Method for producing semiconductor single-walled carbon nanotube dispersion

Abstract

In one embodiment, the present application relates to a method for producing a semiconductive single-wall carbon nanotube dispersion liquid, the method comprising a step of collecting a supernatant containing semiconductive SWCNTs after centrifugation of a separated SWCNT dispersion liquid containing SWCNTs including semiconductive SWCNTs and metallic SWCNTs, an aqueous medium, and a polymer, the polymer being a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below. 0 -COOM (1); CH2=CR 5 -COO- (EO) p -(PO) q -R 6 (3).

Description

TECHNICAL FIELD

[0001] The present application relates to a production method of a semiconductor single-walled carbon nanotube dispersion liquid, a production method of a semiconductor single-walled carbon nanotube including the production method as a step, a separation method of a metallic single-walled carbon nanotube and a semiconductor single-walled carbon nanotube, and the like. BACKGROUND

[0002] In recent years, carbon materials of nanometer size are expected to be applied to various fields due to their physical properties and chemical properties. As one of such materials, there are carbon nanotubes (hereinafter sometimes referred to as "CNTs"). CNTs have a structure in which graphene sheets are rolled into a cylindrical shape, and CNTs in which the cylinder is composed of only one layer are referred to as single-walled carbon nanotubes (hereinafter sometimes referred to as "SWCNTs").

[0003] It is known that CNTs differ in electric properties and the like depending on the rolling method of graphene sheets, diameter, and the like. In particular, SWCNTs greatly differ due to the influence of quantum effects, and thus there are SWCNTs that exhibit metallic properties (metallic SWCNTs) and SWCNTs that exhibit semiconducting properties (semiconductor SWCNTs). As a production method of SWCNTs, there are known synthesis methods such as a high-pressure carbon monoxide disproportionation method (HiPco method), a modified direct injection pyrolysis synthesis method (e-DIPS method), an arc discharge method, and a laser ablation method, however, no technology for producing only either type of CNT has been established at present, and when SWCNTs are applied to various uses, it is necessary to separate SWCNTs of a type targeted from a mixture thereof. With regard to metallic SWCNTs, it is expected to be used for touch panels, transparent electrodes for solar cells, fine wiring of devices, and the like by taking advantage of their excellent conductivity, and with regard to semiconductor SWCNTs, it is expected to be applied to transistors, sensors, and the like.

[0004] Several methods for separating metallic SWCNTs and semiconductor SWCNTs have been reported, and in Japanese Patent Application Publication No. 2019-202912 (Patent Literature 1), a separation method is disclosed in which separation of metallic SWCNTs and semiconductor SWCNTs in a separated SWCNT dispersion liquid is performed by using a specific copolymer as a separation agent with a simple operation. Specifically, a production method of a semiconductor SWCNT dispersion liquid is disclosed which includes a step of, after centrifuging a separated SWCNT dispersion liquid containing polyacrylic acid as a dispersion agent, collecting a supernatant containing semiconductor SWCNTs from the separated dispersion liquid. SUMMARY

[0005] In one mode, the present application relates to a production method of a semiconductor SWCNT dispersion liquid, the production method including:

[0006] a process of preparing a separated SWCNT dispersion liquid containing SWCNTs, an aqueous medium, and a polymer, the SWCNTs containing semiconducting SWCNTs and metallic SWCNTs; and

[0007] a process of collecting a supernatant containing the semiconducting SWCNTs from the separated SWCNT dispersion liquid subjected to the centrifugal separation,

[0008] The polymer is a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below.

[0009] CH2=CR 0 -COOM (1)

[0010] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having a structure represented by formula (2) below.

[0011] [Chemical Formula 1]

[0012]

[0013] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, which optionally has a hydroxyl group.

[0014] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0015] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6 represents a hydrogen atom, or a hydrocarbon group having a carbon number of 1 or more and 5 or less, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

[0016] In one embodiment, the present application relates to a method for producing semiconducting SWCNTs, the method including a process of filtering a semiconducting SWCNT dispersion liquid obtained by the method for producing a semiconducting SWCNT dispersion liquid according to the above-described present application, and collecting semiconducting SWCNTs.

[0017] In one embodiment, the present application relates to a method for producing semiconducting SWCNTs, the method comprising: a step of drying a semiconducting SWCNT dispersion obtained by the method for producing a semiconducting SWCNT dispersion according to the present application to obtain a mixture containing semiconducting SWCNTs and the above-described copolymer; and a step of removing the above-described copolymer from the above-described mixture and collecting semiconducting SWCNTs.

[0018] In one embodiment, the present application relates to a method for separating semiconducting SWCNTs from metallic SWCNTs, the method comprising:

[0019] a step of producing a separated SWCNT dispersion containing SWCNTs, an aqueous medium, and a polymer, the SWCNTs containing semiconducting SWCNTs and metallic SWCNTs; and

[0020] a step of collecting a supernatant containing the above-described semiconducting SWCNTs from the separated SWCNT dispersion subjected to centrifugal separation,

[0021] the above-described polymer is a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below.

[0022] CH2=CR 0 -COOM (1)

[0023] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having a structure represented by formula (2) below.

[0024] [Chemical Formula 2]

[0025]

[0026] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, which optionally has a hydroxyl group.

[0027] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0028] In formula (3), R 5 represents a hydrogen atom or a methyl group. R6 It represents a hydrogen atom or a hydrocarbon group with 1 or more carbon atoms and less than 5 carbon atoms. EO represents ethylene oxide, PO represents propylene oxide, p represents the average number of moles of ethylene oxide added, which is 1 or more and less than 120, and q represents the average number of moles of propylene oxide added, which is 0 or more and less than 50.

[0029] In one embodiment, the present invention relates to a method for manufacturing an ink containing semiconductor SWCNTs, the method comprising, as a step, the method for manufacturing a semiconductor SWCNT dispersion of the present invention or the method for manufacturing semiconductor SWCNTs of the present invention.

[0030] In one embodiment, the present invention relates to an ink containing a semiconductor SWCNT, comprising at least one of an organic solvent and water, a semiconductor SWCNT, and a copolymer comprising structural unit A derived from a monomer of formula (1) below and structural unit B derived from a monomer of formula (3) below.

[0031] CH2=CR 0 -COOM (1)

[0032] In equation (1), R 0 represents a hydrogen atom or a methyl group. M represents any of a hydrogen atom, a metal atom, or a group with the structure shown in formula (2) below.

[0033] [Chemistry 3]

[0034]

[0035] In equation (2), R 1 R 2 R 3 R 4 Each can independently represent a hydrogen atom, or optionally an alkyl group having 1 or more but less than 2 carbon atoms and a hydroxyl group.

[0036] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0037] In equation (3), R 5 Represents a hydrogen atom or a methyl group. R 6 It represents a hydrogen atom or a hydrocarbon group with 1 or more carbon atoms and less than 5 carbon atoms. EO represents ethylene oxide, PO represents propylene oxide, p represents the average number of moles of ethylene oxide added, which is 1 or more and less than 120, and q represents the average number of moles of propylene oxide added, which is 0 or more and less than 50. Detailed Implementation

[0038] On the basis of the high separation of semiconducting SWCNTs being desired, it is also desirable that the resulting semiconducting SWCNT dispersion liquid have good dispersion stability.

[0039] In one embodiment, the present application relates to a method for producing a semiconducting SWCNT dispersion liquid that can achieve both high separation of semiconducting SWCNTs and dispersion stability of the resulting semiconducting SWCNT dispersion liquid, and a method for separating semiconducting SWCNTs from metallic SWCNTs. In one embodiment, the present application relates to a method for producing semiconducting SWCNTs including the above-mentioned production method as one step, and a method for producing an ink containing semiconducting SWCNTs, and in one embodiment, the present application relates to an ink containing semiconducting SWCNTs.

[0040] The present application is based on the insight that, by including a specific polymer in a separated SWCNT dispersion liquid, both high separation of semiconducting SWCNTs and dispersion stability of semiconducting SWCNTs in the resulting semiconducting SWCNT dispersion liquid can be achieved well.

[0041] The details of the mechanism by which the effects of the present application are manifested are not clear, but the following can be inferred. In the present application, it is inferred that because the separated SWCNT dispersion liquid contains a copolymer including structural unit A from the monomer represented by the above-mentioned formula (1), semiconducting SWCNTs are selectively dispersed in the above-mentioned dispersion liquid, while metallic SWCNTs undergo aggregation, and thus are targeted for centrifugal separation, thereby achieving good separation of metallic SWCNTs from semiconducting SWCNTs and an increase in the separation of semiconducting SWCNTs. In addition, it is inferred that because the above-mentioned copolymer includes structural unit B from the monomer represented by the above-mentioned formula (3), the dispersion stability of semiconducting SWCNTs in the resulting semiconducting SWCNT dispersion liquid becomes good. However, the present application is not explained by these mechanisms alone.

[0042] According to the present application, a method for producing a semiconducting SWCNT dispersion liquid that can achieve both high separation of semiconducting SWCNTs and dispersion stability of the resulting semiconducting SWCNT dispersion liquid, and a method for separating semiconducting SWCNTs from metallic SWCNTs can be provided. In one embodiment, the present application can provide a method for producing semiconducting SWCNTs including the above-mentioned production method as one step, and a method for producing an ink containing semiconducting SWCNTs, and can provide an ink containing semiconducting SWCNTs.

[0043] [Method for producing semiconducting SWCNT dispersion liquid, method for separating semiconducting SWCNTs from metallic SWCNTs]

[0044] In one embodiment, the present application relates to a method for producing a semiconductor-type SWCNT dispersion liquid (hereinafter also referred to as "the dispersion liquid producing method of the present application") including the following process A and process B. In another embodiment, the present application relates to a method for separating a semiconductor-type SWCNT from a metal-type SWCNT (hereinafter also referred to as "the separation method of the present application") including the following process A and process B.

[0045] (Process A) A separated SWCNT dispersion liquid is prepared, the separated SWCNT dispersion liquid containing a SWCNT, a copolymer, and an aqueous medium, the SWCNT (hereinafter also referred to as "SWCNT mixture") containing a semiconductor-type SWCNT and a metal-type SWCNT, the copolymer containing a structural unit A derived from a monomer (hereinafter also referred to as "monomer A") represented by the following formula (1) and a structural unit B derived from a monomer (hereinafter also referred to as "monomer B") represented by the following formula (3).

[0046] (Process B) After centrifugal separation of the separated SWCNT dispersion liquid, a supernatant containing the semiconductor-type SWCNT is collected from the separated SWCNT dispersion liquid subjected to the centrifugal separation.

[0047] CH2=CR 0 -COOM (1)

[0048] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having a structure represented by the following formula (2).

[0049] [Chem. 4]

[0050]

[0051] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, which optionally has a hydroxyl group.

[0052] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0053] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6represents a hydrogen atom, or a hydrocarbon group having a carbon number of 1 or more and 5 or less, EO represents an ethyleneoxy group (hereinafter also referred to as "an EO group"), PO represents a propyleneoxy group (hereinafter also referred to as "a PO group"), p represents the average addition mole number of ethyleneoxy groups, and is 1 or more and 120 or less, and q represents the average addition mole number of propyleneoxy groups, and is 0 or more and 50 or less.

[0054] In the present application, the "supernatant liquid containing the above-described semiconductor-type SWCNT" means a supernatant liquid in which the ratio of the semiconductor-type SWCNT to the metal-type SWCNT is increased, with respect to the ratio of the semiconductor-type SWCNT to the metal-type SWCNT in the separated SWCNT dispersion liquid obtained in the above-described process A in the production method of the dispersion liquid of the present application and the separation method of the present application, and the above-described supernatant liquid is a semiconductor-type SWCNT dispersion liquid. In the present application, the case where the metal-type SWCNT is contained in the supernatant liquid in a relatively small amount compared to the semiconductor-type SWCNT is not excluded. If the separation property of the semiconductor-type SWCNT is improved, the proportion of the semiconductor-type SWCNT in the SWCNT in the supernatant liquid is increased, and the supernatant liquid becomes more useful as a material for semiconductor devices.

[0055] In the above-described process B in the production method of the dispersion liquid of the present application and the separation method of the present application, the operation of collecting the supernatant liquid can be performed, for example, by separating the supernatant liquid from the residue thereof. The above-described residue contains a precipitate containing a relatively large amount of the metal-type SWCNT compared to the semiconductor-type SWCNT.

[0056] [Process A]

[0057] In the above-described process A in the production method of the dispersion liquid of the present application and the separation method of the present application, in one or more embodiments, after a mixed liquid (hereinafter, sometimes simply referred to as "mixed liquid A") containing at least a copolymer containing a structural unit A derived from the above-described monomer A and a structural unit B derived from the above-described monomer B, the above-described SWCNT mixture, and an aqueous medium is prepared, the mixed liquid A is used as a target of dispersion treatment. The mixed liquid A can be prepared, for example, by adding the above-described SWCNT mixture to an aqueous solution of the above-described copolymer.

[0058] [Copolymer containing a structural unit A derived from monomer A and a structural unit B derived from monomer B]

[0059] From the viewpoint of improving the separation property of the semiconductor-type SWCNT, the above-described copolymer is water-soluble. In the present application, the "water-soluble" means that 1 g or more of the polymer is dissolved in 100 g of water at 20°C.

[0060] (Structural unit A derived from monomer A)

[0061] The structural unit A contained in the above copolymer is derived from the structural unit of monomer A shown in formula (1) above. In formula (1) above, from the viewpoint of improving the separability of semiconductor SWCNT, R 0 M is preferably methyl. In the above formula (1), from the viewpoint of improving the separability and productivity of semiconductor SWCNTs, M is a hydrogen atom, a metal atom, or a group with the structure shown in the above formula (2). From the viewpoint of improving the separability, productivity, and versatility of semiconductor SWCNTs, M is preferably a hydrogen atom or a group with the structure shown in the above formula (2), and more preferably a hydrogen atom. The monomer A that provides structural unit A is preferably methacrylic acid.

[0062] (Structural unit B derived from monomer B)

[0063] The structural unit B contained in the above copolymer is a structural unit derived from monomer B shown in formula (3) above. The structural unit B contained in the above copolymer can be one type or a combination of two or more types.

[0064] In equation (3) above, from the viewpoint of improving the separation of semiconductor-type SWCNTs, R 5 Methyl is preferred.

[0065] In the above formula (3), from the perspective of balancing the improvement of the separability of semiconductor SWCNTs and the dispersion stability of semiconductor SWCNT dispersions, as well as the availability of monomers, R 6 This indicates a hydrocarbon group containing 1 or more hydrogen atoms and 5 or fewer carbon atoms. In R... 6 In the case of a hydrocarbon group, from the viewpoints of improving the separability of semiconductor SWCNTs and the dispersion stability of semiconductor SWCNT dispersions, as well as the viewpoints of monomer availability, the number of carbon atoms is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less. 6 Examples of hydrocarbon groups include alkyl groups. As R 6 Specific examples include at least one selected from butyl, ethyl, methyl, and hydrogen atoms. From the viewpoint of balancing the improved separability and the dispersion stability mentioned above, methyl or hydrogen atoms are preferred, and methyl is more preferred. From the viewpoint of balancing the improved separability of semiconductor SWCNTs and the dispersion stability of semiconductor SWCNT dispersions, the copolymer more preferably contains R. 6 The structural unit B and R are hydrocarbon groups, preferably having 1 or more and 4 or less carbon atoms, more preferably 1 or more and 3 or less. 6 Both are structural unit B for hydrogen. The number of terminal carbons in structural unit B, i.e., R... 6 The number of carbon atoms can be calculated from the chemical shift in nuclear magnetic resonance, specifically using the method described in the examples.

[0066] The monomer B that provides the structural unit B is preferably 2-hydroxyethyl methacrylate (HEMA), butoxy polyethylene glycol methacrylate, ethoxy polyethylene glycol methacrylate, methoxy polyethylene glycol (meth)acrylate (PEG(M)A), and more preferably methoxy polyethylene glycol methacrylate (PEGMA).

[0067] In formula (3), p is 1 or more from the viewpoint of improving the separation of semiconductive SWCNTs, and is 120 or less, preferably 100 or less, more preferably 90 or less, further preferably 60 or less, furthermore preferably 45 or less, furthermore preferably 25 or less, from the viewpoint of improving the separation of semiconductive SWCNTs and the viewpoint of the availability of the monomer.

[0068] In formula (3), q is 0 or more and 50 or less, preferably 0 or more and 30 or less, more preferably 0 or more and 10 or less, further preferably 0 or more and 5 or less, furthermore preferably 0 or more and 3 or less, furthermore preferably 0, from the viewpoint of the water solubility of the copolymer, the viewpoint of improving the separation of semiconductive SWCNTs, and the viewpoint of the availability of the monomer.

[0069] In formula (3), q / (p+q) is preferably 0.7 or less, more preferably 0.4 or less, further preferably 0, from the viewpoint of the water solubility of the copolymer, the viewpoint of improving the separation of semiconductive SWCNTs, and the viewpoint of the availability of the monomer.

[0070] In formula (3), the addition order of the EO group and the PO group is not limited, and in the case where q is 2 or more, either of block bonding or random bonding can be adopted.

[0071] In the case where the structural unit B contained in the above-described copolymer is a combination of two or more, the combination of a structural unit B1 in which the average number of moles of the addition of the EO group p is 4 or more and 120 or less and a structural unit B2 in which the average number of moles of the addition of the EO group p is 1 or more and less than 4 is preferred from the viewpoint of improving the separation of semiconductive SWCNTs. The average number of moles of the addition of the EO group p of the structural unit B1 is preferably 100 or less, more preferably 90 or less, further preferably 60 or less, furthermore preferably 45 or less, furthermore preferably 25 or less, from the viewpoint of improving the separation of semiconductive SWCNTs. The average number of moles of the addition of the EO group p of the structural unit B2 is preferably 3 or less, more preferably 2 or less, further preferably 1, from the viewpoint of improving the separation of semiconductive SWCNTs.

[0072] R of the structural unit B1 6 It is preferably a hydrocarbon group having 1 or more and 5 or less carbon atoms, more preferably a hydrocarbon group having 1 or more and 4 or less carbon atoms, further preferably a hydrocarbon group having 1 or more and 3 or less carbon atoms. R of the structural unit B26 Preferably, it is a hydrogen atom.

[0073] In the case where the structural unit B contained in the above-described copolymer is a combination of the structural unit B1 and the structural unit B2, the molar ratio of the structural unit B1 to the structural unit B2 (B1 / B2) in the above-described copolymer is preferably 0.01 or more, more preferably 0.03 or more, and further preferably 0.05 or more, from the viewpoint of improving the separation property of semiconducting SWCNTs, and is preferably 0.5 or less, more preferably 0.4 or less, and further preferably 0.3 or less, from the viewpoint of improving the separation property of semiconducting SWCNTs.

[0074] In the case where the structural unit B contained in the above-described copolymer is a combination of the structural unit B1 and the structural unit B2, the mass ratio of the structural unit B1 to the structural unit B2 (B1 / B2) in the above-described copolymer is preferably 0.1 or more, more preferably 0.2 or more, and further preferably 0.4 or more, from the viewpoint of improving the separation property of semiconducting SWCNTs, and is preferably 5 or less, more preferably 3 or less, and further preferably 1 or less, from the viewpoint of improving the separation property of semiconducting SWCNTs.

[0075] The content of the structural unit A (mass %) in the total structural units of the above-described copolymer is preferably greater than 0 mass %, more preferably 1 mass % or more, further preferably 2 mass % or more, and still further preferably 3 mass % or more, from the viewpoint of improving the separation property of semiconducting SWCNTs, and is preferably 80 mass % or less, more preferably 50 mass % or less, further preferably 30 mass % or less, and still further preferably 20 mass % or less, from the viewpoint of improving the dispersion stability of a semiconducting SWCNT dispersion.

[0076] The content of the structural unit A (mol %) in the total structural units of the above-described copolymer is preferably greater than 0 mol %, more preferably 1 mol % or more, further preferably 3 mol % or more, still further preferably 5 mol % or more, and yet further preferably 8 mol % or more, from the viewpoint of improving the separation property of semiconducting SWCNTs, and is preferably less than 100 mol %, more preferably 90 mol % or less, further preferably 80 mol % or less, still further preferably 60 mol % or less, yet further preferably 40 mol % or less, and yet further preferably 25 mol % or less, from the viewpoint of improving the dispersion stability of a semiconducting SWCNT dispersion.

[0077] From the viewpoint of improving the dispersion stability of the semiconductor-type SWCNT dispersion liquid, the content of the structural unit B in the total structural units of the above-described copolymer (mass%) is preferably greater than 10 mass%, more preferably 50 mass% or greater, further preferably 70 mass% or greater, and more further preferably 80 mass% or greater, and from the viewpoint of improving the separation property of the semiconductor-type SWCNT, is preferably less than 100 mass%, more preferably 97 mass% or less, further preferably 95 mass% or less, and more further preferably 92 mass% or less.

[0078] From the viewpoint of improving the dispersion stability of the semiconductor-type SWCNT dispersion liquid, the content of the structural unit B in the total structural units of the above-described copolymer (mol%) is preferably greater than 0 mol%, more preferably 10 mol% or greater, further preferably 20 mol% or greater, more further preferably 30 mol% or greater, and more further preferably 50 mol% or greater, and from the viewpoint of improving the separation property of the semiconductor-type SWCNT, is preferably less than 100 mol%, more preferably 97 mol% or less, further preferably 95 mol% or less, and more further preferably 92 mol% or less.

[0079] From the viewpoint of improving both the separation property of the semiconductor-type SWCNT and the dispersion stability of the semiconductor-type SWCNT dispersion liquid, the total content of the structural unit A and the structural unit B in the total structural units of the above-described copolymer (mass%) is preferably 80 mass% or greater, more preferably 90 mass% or greater, further preferably 95 mass% or greater, and more further preferably 99 mass% or greater, and is 100 mass% or less. From the viewpoint of improving the separation property of the semiconductor-type SWCNT, it is more further preferably substantially 100 mass%.

[0080] From the viewpoint of improving both the separation property of the semiconductor-type SWCNT and the dispersion stability of the semiconductor-type SWCNT dispersion liquid, the total content of the structural unit A and the structural unit B in the total structural units of the above-described copolymer (mol%) is preferably 80 mol% or greater, more preferably 90 mol% or greater, further preferably 95 mol% or greater, and more further preferably 99 mol% or greater, and is 100 mol% or less. From the viewpoint of improving the separation property of the semiconductor-type SWCNT, it is more further preferably substantially 100 mol%.

[0081] The above copolymer can contain a structural unit C other than the structural units A and B, within a range that does not impair the effects of the present application. The structural unit C can be one or a combination of two or more. As the monomer C that provides the structural unit C, for example, a structural unit from a carboxylic acid-based monomer other than monomer A such as maleic acid, or a nonionic monomer other than the structural unit B can be given. As the nonionic monomer, at least one selected from a (meth)acrylate-based monomer, a (meth)acrylamide-based monomer, a styrene-based monomer, and a (meth)acrylonitrile-based monomer can be given, among which a (meth)acrylate-based monomer is preferred.

[0082] In the case where the monomer C is a (meth)acrylate-based monomer, as the monomer C, for example, at least one selected from methyl (meth)acrylate, ethyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and benzyl (meth)acrylate can be given.

[0083] In the case where the monomer C is a (meth)acrylamide-based monomer, as the monomer C, for example, at least one of acrylamide, methacrylamide, dimethylacrylamide, and dimethylmethacrylamide can be given.

[0084] In the case where the monomer C is a styrene-based monomer, as the monomer C, for example, styrene, or methylstyrene can be given.

[0085] In the case where the monomer C is a (meth)acrylonitrile-based monomer, as the monomer C, for example, acrylonitrile, or methacrylonitrile can be given.

[0086] From the viewpoint of both improving the separation property of the semiconductive SWCNT and improving the dispersion stability of the semiconductive SWCNT dispersion liquid, the content of the structural unit C in the copolymer is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, still further preferably 1% by mass or less, and still further preferably substantially not contained. The "substantially not contained" here means that it is not intentionally contained, for example, in the raw material monomer that constitutes the structural unit A and the structural unit B, and the case where it is not intentionally contained is equivalent to "substantially not contained".

[0087] From the viewpoint of improving the separation property of the semiconductive SWCNT, the mass ratio (A / B) of the structural unit A to the structural unit B in the above copolymer is preferably greater than 0, more preferably 0.01 or more, further preferably 0.03 or more, still further preferably 0.05 or more, and from the viewpoint of improving the dispersion stability of the semiconductive SWCNT dispersion liquid, it is preferably 10 or less, more preferably 5 or less, further preferably 3 or less, still further preferably 1.5 or less, still further preferably 0.5 or less, and still further preferably 0.4 or less.

[0088] From the viewpoint of improving the separation property of semiconductive SWCNT, the molar ratio (A / B) of the structural unit A to the structural unit B in the above copolymer is preferably greater than 0, more preferably 0.01 or greater, further preferably 0.05 or greater, and still further preferably 0.1 or greater, and from the viewpoint of improving the dispersion stability of the semiconductive SWCNT dispersion liquid, is preferably 30 or less, more preferably 10 or less, further preferably 5 or less, still further preferably 3 or less, yet further preferably 2 or less, and still further preferably 1.1 or less, and still further preferably 0.5 or less.

[0089] From the viewpoint of improving the separation property of semiconductive SWCNT, the weight average molecular weight of the above copolymer is preferably 1000 or greater, more preferably 2000 or greater, further preferably 3000 or greater, and still further preferably 4000 or greater, and from the viewpoint of improving the separation property of semiconductive SWCNT, is preferably 250,000 or less, more preferably 150,000 or less, further preferably 120,000 or less, and still further preferably 110,000 or less. In the present application, the weight average molecular weight of the above copolymer is a value obtained by a gel permeation chromatography method, and specifically, can be measured by the method described in the examples.

[0090] From the viewpoint of improving the separation property of semiconductive SWCNT and the viewpoint of improving the productivity, the mass ratio (copolymer / SWCNT) of the above copolymer to the SWCNT in the above mixed liquid A and the separated SWCNT dispersion liquid is preferably 0.5 or greater, more preferably 1 or greater, further preferably 2 or greater, and still further preferably 4 or greater, and from the same viewpoints, is preferably 100 or less, more preferably 70 or less, further preferably 50 or less, and still further preferably 20 or less.

[0091] From the viewpoint of improving the separation property of semiconductive SWCNT and the viewpoint of improving the productivity, the content of the above copolymer in the above mixed liquid A and the separated SWCNT dispersion liquid is preferably 0.05% by mass or greater, more preferably 0.1% by mass or greater, further preferably 0.15% by mass or greater, and still further preferably 0.2% by mass or greater, and from the same viewpoints, is preferably 10% by mass or less, more preferably 7% by mass or less, and further preferably 5% by mass or less.

[0092] [SWCNT]

[0093] There is no particular limitation on the SWCNT used in the preparation of the above-described mixed solution A and the separated SWCNT dispersion liquid. The SWCNT is, for example, a material synthesized by a conventionally known synthesis method such as a HiPco method, an e-DIPS method, and the like, and can include a variety of materials in terms of chirality and diameter. The metallic SWCNT and the semiconducting SWCNT can be included at an arbitrary ratio, and the SWCNT generally synthesized is a SWCNT mixture including about 1 / 3 of the metallic SWCNT and about 2 / 3 of the semiconducting SWCNT.

[0094] From the viewpoint of improving the separation of the semiconducting SWCNT, the average diameter of the SWCNT is preferably 0.5 nm or more, more preferably 0.8 nm or more, and from the same viewpoint, is preferably 3 nm or less, more preferably 2 nm or less. The average diameter of the SWCNT can be calculated by measuring the diameters of 10 or more CNTs from an image obtained using a transmission electron microscope and averaging the diameters.

[0095] From the viewpoint of the electrical properties, the average length of the SWCNT is preferably 0.1 μm or more, more preferably 0.3 μm or more, and further preferably 0.5 μm or more, and from the viewpoint of improving the separation of the semiconducting SWCNT and the viewpoint of improving the productivity, is preferably 100 μm or less, more preferably 50 μm or less, and further preferably 20 μm or less, and more further preferably 10 μm or less. The average length of the SWCNT can be calculated by measuring the lengths of 10 or more CNTs from an image obtained using a transmission electron microscope and averaging the lengths.

[0096] From the viewpoint of improving the separation of the semiconducting SWCNT, the content of the SWCNT in the above-described mixed solution A and the separated SWCNT dispersion liquid is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and further preferably 0.03% by mass or more, and from the viewpoint of improving the separation of the semiconducting SWCNT and the viewpoint of improving the productivity, is preferably 5% by mass or less, more preferably 1% by mass or less, and further preferably 0.5% by mass or less.

[0097] [Aqueous medium]

[0098] The above-described mixed solution A and the separated SWCNT dispersion liquid include an aqueous medium as a dispersion medium. As the aqueous medium, water is preferred, and from the viewpoint of improving the separation of the semiconducting SWCNT and the viewpoint of improving the productivity, the water is preferably pure water, ion-exchanged water, purified water, or distilled water, and more preferably pure water.

[0099] The above mixed solution A and the separated SWCNT dispersion liquid can contain, in addition to water, a lower alcohol such as methanol, ethanol, or isopropanol; acetone; tetrahydrofuran; dimethylformamide; or another water-soluble organic solvent as the aqueous medium.

[0100] In the case where the aqueous medium is a combination of water and a dispersion medium other than water, the proportion of water in the dispersion medium is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more from the viewpoint of improving the separation of semiconducting SWCNTs.

[0101] The content of the aqueous medium in the above mixed solution A and the separated SWCNT dispersion liquid is preferably 85% by mass or more, more preferably 92% by mass or more, and further preferably 96% by mass or more from the viewpoint of improving the separation of semiconducting SWCNTs and the viewpoint of improving productivity, and is preferably 99.9% by mass or less, more preferably 99.8% by mass or less, further preferably 99.5% by mass or less, and more further preferably 99.0% by mass or less from the same viewpoints.

[0102] The dispersion treatment of the mixed solution A can be performed using, for example, a bath-type ultrasonic disperser, a homomixer, a high-pressure homogenizer, an ultrasonic homogenizer, a jet mill, a bead mill, a millser, or another disperser.

[0103] In the process A, a defoaming treatment can be performed before the dispersion treatment of the mixed solution A.

[0104] [Process B]

[0105] In the above process B in the method of producing the dispersion liquid of the present application and the separation method of the present application, the separated SWCNT dispersion liquid obtained in the process A is subjected to centrifugal separation, and the supernatant containing semiconducting SWCNTs is collected from the separated SWCNT dispersion liquid subjected to the centrifugal separation. The ratio of semiconducting SWCNTs is increased in the above supernatant relative to the ratio of semiconducting SWCNTs to metallic SWCNTs in the separated SWCNT dispersion liquid before being subjected to the centrifugal separation. The ratio varies depending on the centrifugal separation conditions and the like, and the rotation speed of the centrifuge is preferably 5,000 rpm or more, and more preferably 10,000 rpm or more from the viewpoint of improving the separation of semiconducting SWCNTs and the viewpoint of improving productivity, and is preferably 100,000 rpm or less, and more preferably 70,000 rpm or less from the same viewpoints. The gravitational acceleration of the centrifuge is preferably 10 kG or more, and more preferably 50 kG or more from the viewpoint of improving the separation of semiconducting SWCNTs and the viewpoint of improving productivity, and is preferably 1,000 kG or less, and more preferably 500 kG or less from the same viewpoints.

[0106] [Method for producing semiconductor SWCNTs and semiconductor SWCNTs]

[0107] If semiconductor SWCNTs are collected from the semiconductor SWCNT dispersion liquid produced by the method for producing a semiconductor SWCNT dispersion liquid according to the present application, semiconductor SWCNTs can be produced. The collection of semiconductor SWCNTs from the semiconductor SWCNT dispersion liquid can be performed, for example, by filtering the semiconductor SWCNTs from the semiconductor SWCNT dispersion liquid using a membrane filter and then drying them. In the case of filtering the semiconductor SWCNTs from the semiconductor SWCNT dispersion liquid, the filtering can be performed after performing a pretreatment such as reprecipitation of the semiconductor SWCNTs in the semiconductor SWCNT dispersion liquid. Alternatively, it can be performed by drying the semiconductor SWCNT dispersion liquid and removing the above-described copolymer coexisting therewith by washing, heat decomposition, or the like. Thus, in one mode, the present application relates to a method for producing semiconductor SWCNTs (hereinafter also referred to as "Method A for producing semiconductor SWCNTs according to the present application"), which includes a step of filtering the semiconductor SWCNT dispersion liquid obtained by the method for producing a semiconductor SWCNT dispersion liquid according to the present application and collecting semiconductor SWCNTs. In another mode, the present application relates to a method for producing semiconductor SWCNTs (hereinafter also referred to as "Method B for producing semiconductor SWCNTs according to the present application"), which includes a step of drying the semiconductor SWCNT dispersion liquid obtained by the method for producing a semiconductor SWCNT dispersion liquid according to the present application to obtain a mixture containing semiconductor SWCNTs and the above-described copolymer, and a step of removing the above-described copolymer from the mixture and collecting semiconductor SWCNTs. In another mode, the present application relates to semiconductor SWCNTs obtained by Method A or B for producing semiconductor SWCNTs according to the present application (hereinafter also referred to as "semiconductor SWCNTs according to the present application").

[0108] [Method for producing an ink containing semiconductor SWCNTs]

[0109] In one embodiment, the present application relates to a method for producing an ink containing semiconductive SWCNTs (hereinafter also referred to as "the method for producing an ink containing semiconductive SWCNTs of the present application") including the method for producing a semiconductive SWCNT dispersion of the present application or the method for producing semiconductive SWCNTs of the present application as one step. One embodiment of the method for producing an ink containing semiconductive SWCNTs of the present application includes, for example, the method for producing semiconductive SWCNTs A or B of the present application as one step, and further includes a step of mixing at least one of an organic solvent and water, at least one of a surfactant and a resin used as necessary, and the above semiconductive SWCNTs. Another embodiment of the method for producing an ink containing semiconductive SWCNTs of the present application includes, for example, the method for producing a semiconductive SWCNT dispersion of the present application as one step, and further includes a step of mixing the above semiconductive SWCNT dispersion and at least one of an organic solvent, a surfactant and a resin which can be miscible with the above dispersion used as necessary.

[0110] As the above organic solvent, for example, aliphatic solvents such as n-hexane, n-octane, n-decane and the like; alicyclic solvents such as cyclohexane and the like; aromatic solvents such as benzene, toluene and the like; alcohol solvents such as methanol, ethanol and the like; glycol ether solvents such as diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, butyl cellosolve and the like can be exemplified. From the viewpoint of improving film formability, the ink containing semiconductive SWCNTs can further include, for example, polystyrene resins, acrylic resins, vinyl resins and the like as the above resin which can be dissolved or dispersed in a solvent, and well-known surfactants, other additives as dispersants. As for the content of semiconductive SWCNTs in the ink containing semiconductive SWCNTs, it is only necessary to be appropriately set according to the use.

[0111] [Ink containing semiconductive SWCNTs]

[0112] In one embodiment, the present application relates to an ink containing semiconductive SWCNTs (hereinafter also referred to as "the ink containing semiconductive SWCNTs of the present application") including at least one of an organic solvent and water, semiconductive single-wall SWCNTs, and a copolymer including structural unit A derived from a monomer represented by the above formula (1) and structural unit B derived from a monomer represented by the above formula (3).

[0113] One embodiment of the ink containing semiconductive SWCNTs of the present application includes at least semiconductive SWCNTs of the present application, a copolymer including structural unit A derived from a monomer represented by the above formula (1) and structural unit B derived from a monomer represented by the above formula (3), and at least one of an organic solvent and water, and further includes a surfactant and a resin as necessary.

[0114] [Method for manufacturing semiconductor device]

[0115] In one embodiment, the present application relates to a method for manufacturing a semiconductor device, including a step of printing or coating an ink containing semiconducting SWCNTs obtained by the method for manufacturing an ink containing semiconducting SWCNTs of the present application on a substrate to form a semiconducting layer.

[0116] In another embodiment, the present application relates to a method for manufacturing a semiconductor device, including a step of forming a semiconducting circuit, a semiconducting film (semiconducting layer) by printing or coating the ink containing semiconducting SWCNTs on a substrate provided with a gate electrode, a source electrode and a drain electrode. As the printing method of the ink containing semiconducting SWCNTs, inkjet printing, screen printing, offset printing, letterpress printing and the like can be mentioned. After forming the semiconducting film by printing or coating, a step of forming a circuit by etching or the like can be included.

[0117] The present application further discloses the following: a method for manufacturing a semiconducting single-walled carbon nanotube dispersion liquid, a method for separating semiconducting single-walled carbon nanotubes from metallic single-walled carbon nanotubes, a method for manufacturing an ink containing semiconducting single-walled carbon nanotubes, and an ink containing semiconducting single-walled carbon nanotubes.

[0118] <1> A method for manufacturing a semiconducting single-walled carbon nanotube dispersion liquid, the method comprising:

[0119] a step of preparing a separated single-walled carbon nanotube dispersion liquid containing semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes, an aqueous medium and a polymer; and

[0120] a step of collecting a supernatant containing the semiconducting single-walled carbon nanotubes from the separated single-walled carbon nanotube dispersion liquid after centrifuging the separated single-walled carbon nanotube dispersion liquid,

[0121] The polymer is a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below.

[0122] CH2=CR 0 -COOM (1)

[0123] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom and a group having a structure represented by formula (2) below.

[0124] [Chemical Formula 5]

[0125]

[0126] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group.

[0127] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0128] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6 represents a hydrogen atom, or a hydrocarbon group having a carbon number of 1 or more and 5 or less, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

[0129] A method for producing a semiconductor single-walled carbon nanotube dispersion liquid, the method comprising:

[0130] a step of preparing a separated single-walled carbon nanotube dispersion liquid containing single-walled carbon nanotubes, an aqueous medium, and a polymer, the single-walled carbon nanotubes containing semiconductor single-walled carbon nanotubes and metallic single-walled carbon nanotubes; and

[0131] a step of, after centrifuging the separated single-walled carbon nanotube dispersion liquid, collecting a supernatant containing the semiconductor single-walled carbon nanotubes from the centrifuged separated single-walled carbon nanotube dispersion liquid,

[0132] the polymer is a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below,

[0133] the content of the structural unit A in all the structural units of the copolymer is greater than 0 mol% and less than 100 mol%, and the content of the structural unit B is greater than 0 mol% and less than 100 mol%.

[0134] CH2=CR 0 -COOM (1)

[0135] In formula (1), R 0represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having a structure represented by the following formula (2).

[0136] [Chemical Formula 6]

[0137]

[0138] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group.

[0139] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0140] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6 represents a hydrogen atom, or a hydrocarbon group having a carbon number of 1 or more and 5 or less, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

[0141] <3> A method for producing a semiconductor single-walled carbon nanotube dispersion liquid, the method comprising:

[0142] a step of preparing a separated single-walled carbon nanotube dispersion liquid containing a single-walled carbon nanotube, an aqueous medium, and a polymer, the single-walled carbon nanotube containing a semiconductor single-walled carbon nanotube and a metallic single-walled carbon nanotube; and

[0143] a step of collecting a supernatant containing the semiconductor single-walled carbon nanotube from the separated single-walled carbon nanotube dispersion liquid after centrifuging the separated single-walled carbon nanotube dispersion liquid,

[0144] the polymer is a copolymer containing a structural unit A derived from a monomer represented by the following formula (1) and a structural unit B derived from a monomer represented by the following formula (3),

[0145] the content of the structural unit A in all the structural units of the copolymer is greater than 0 mol% and less than 100 mol%, and the content of the structural unit B is greater than 0 mol% and less than 100 mol%.

[0146] CH2=CR 0 -COOM (1)

[0147] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having a structure represented by formula (2) described below.

[0148] [Chemical Formula 7]

[0149]

[0150] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, which optionally has a hydroxyl group.

[0151] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0152] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6 represents a hydrogen atom, or a methyl group, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

[0153] <4> The production method of a semiconductor single-walled carbon nanotube dispersion liquid according to any one of <1> to <3>, wherein a mass ratio (A / B) of the structural unit A to the structural unit B in the copolymer is 0.01 or more and 10 or less.

[0154] <5> The production method of a semiconductor single-walled carbon nanotube dispersion liquid according to any one of <1> to <3>, wherein a mole ratio (A / B) of the structural unit A to the structural unit B in the copolymer is 0.05 or more and 30 or less.

[0155] <6> The production method of a semiconductor single-walled carbon nanotube dispersion liquid according to any one of <1> to <5>, wherein a content (mol%) of the structural unit A in all of the structural units of the copolymer is 1 mol% or more and less than 100 mol%.

[0156] <7> The production method of a semiconductor single-walled carbon nanotube dispersion liquid according to any one of <1> to <6>, wherein a content (mol%) of the structural unit B in all of the structural units of the copolymer is more than 0 mol% and less than 100 mol%.

[0157] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to any one of <1> to <7>, wherein the average addition mole number p of the structural unit B1 of ethylene oxide in the structural unit B of the copolymer is 4 or more and less than 120, and the average addition mole number p of the structural unit B2 of ethylene oxide is 1 or more and less than 4.

[0158] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the molar ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.01 or more and 0.5 or less.

[0159] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the mass ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.1 or more and 5 or less.

[0160] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the mass ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.1 or more and 5 or less.

[0161] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the mass ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.1 or more and 5 or less.

[0162] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the mass ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.1 or more and 5 or less.

[0163] The production method of the semiconductor single-walled carbon nanotube dispersion liquid according to <8>, wherein the mass ratio (B1 / B2) of the structural unit B1 to the structural unit B2 in the copolymer is 0.1 or more and 5 or less.

[0164] CH2=CR 0 -COOM (1)

[0165] In formula (1), R 0 represents a hydrogen atom or a methyl group. M represents any one of a hydrogen atom, a metal atom, and a group having the structure shown in formula (2) below.

[0166] [Chemical 8]

[0167]

[0168] In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group.

[0169] CH2=CR 5 -COO-(EO) p -(PO) q -R 6 (3)

[0170] In formula (3), R 5 represents a hydrogen atom or a methyl group. R 6 represents a hydrogen atom, or a methyl group, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

[0171] Hereinafter, the present application will be further explained in detail using examples, however, they are illustrative and the present application is not limited by these examples.

[0172] 1. Measurement method of various parameters

[0173] [Measurement of weight average molecular weight of copolymer]

[0174] The weight average molecular weight of the copolymer used in the preparation of the separated SWCNT dispersion liquid was measured using a gel permeation chromatography (hereinafter also referred to as "GPC") method under the following conditions.

[0175] <GPC conditions>

[0176] Measurement device: HLC-8320 GPC (manufactured by TOSOH CORPORATION)

[0177] Chromatography column: α-M + α-M (manufactured by TOSOH CORPORATION)

[0178] Eluent: 60 mmol / L H3PO4 and 50 mmol / L LiBr in N,N-dimethylformamide (DMF)

[0179] Flow rate: 1.0 mL / min

[0180] Column temperature: 40°C

[0181] Detection: RI

[0182] Sample amount: 0.5 mg / mL

[0183] Standard substance: monodisperse polystyrene (manufactured by TOSOH CORPORATION)

[0184] [Method for measuring the number of EO and PO addition moles]

[0185] The number of EO and PO addition moles of the copolymer used in the preparation of the isolated SWCNT dispersion was measured using nuclear magnetic resonance method (hereinafter also referred to as "NMR") under the following conditions. The number of EO and PO addition moles was calculated from the integral value of the chemical shift.

[0186] <NMR conditions>

[0187] Measurement device: Vnmrs400 (manufactured by Agilent)

[0188] Measurement solvent: deuterated chloroform (containing 0.05% TMS) (manufactured by FUJIFILM and Otsuka Pharmaceutical Co., Ltd.)

[0189] Measurement chemical species: 1H

[0190] [Method for measuring the number of terminal carbons of PEGMA in the copolymer]

[0191] The number of terminal carbons of PEGMA in the copolymer used in the preparation of the isolated SWCNT dispersion was measured using nuclear magnetic resonance method (hereinafter also referred to as "NMR") under the following conditions. The number of terminal carbons was calculated from the integral value of the chemical shift.

[0192] <NMR conditions>

[0193] Measurement device: Vnmrs400 (manufactured by Agilent)

[0194] Measurement solvent: deuterated chloroform (containing 0.05% TMS) (manufactured by FUJIFILM and Otsuka Pharmaceutical Co., Ltd.)

[0195] Measurement chemical species: 1H, 13C

[0196] [Evaluation of water solubility]

[0197] To 100 g of water at 20°C, 1 g of the copolymer was added, and stirred for 5 minutes, and the presence or absence of insoluble matter was observed visually. In the case where no insoluble matter was observed, it was judged to be water-soluble. In Tables 1 and 2, the case where it was judged to be water-soluble is denoted as A, and the case where it was judged to be not water-soluble is denoted as B.

[0198] [Measurement of average diameter and average length of SWCNT]

[0199] The average diameter and average length of the SWCNTs were calculated by measuring the diameter and length of 10 or more CNTs from images obtained using a transmission electron microscope and averaging the values.

[0200] 2. Production of copolymers a to i

[0201] [ Copolymer a ]

[0202] Into a reaction vessel equipped with a stirrer, a reflux tube, a thermometer, a dropping funnel 1, and a dropping funnel 2 were charged ethanol (manufactured by FUJIFILM Wako Pure Chemical Corporation) 15 g. After the reaction system was replaced with nitrogen gas while stirring, the temperature was raised to 90°C. A mixed solution of a monomer (methacrylic acid (manufactured by FUJIFILM Wako Pure Chemical Corporation) 15 g (71.2 mol%) and methoxypolyethylene glycol (9) monomethacrylate (manufactured by SHIN-NYU SEIKA KAGAKU KOGYO CO., LTD., "M-90G" 35 g (28.8 mol%)) and ethanol 10 g was prepared in the dropping funnel 1, and a mixed solution of 3-mercapto-1,2-propanediol (manufactured by FUJIFILM Wako Pure Chemical Corporation) 1.59 g (6.0 mol% relative to the total monomer) as a chain transfer agent and 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by FUJIFILM Wako Pure Chemical Corporation, "V-65B") 0.304 g (0.5 mol% relative to the total monomer) as a polymerization initiator and ethanol 50.5 g were prepared in the dropping funnel 2. The mixed solutions were simultaneously added dropwise to the reaction vessel over 1 hour. After the addition was completed, the reaction was completed by aging for 1 hour with stirring to obtain copolymer a.

[0203] [ Copolymers b to i ]

[0204] The production method of copolymer a was repeated except that the monomer, the amount of monomer, the amount of chain transfer agent, and the amount of polymerization initiator were changed to those shown in Table 1 to obtain copolymers b to i.

[0205] The physical properties of the obtained copolymers a to i are shown in Table 1 below.

[0206] The monomers used in the production of the copolymers a to i are shown below.

[0207] (Monomer A)

[0208] MAA: methacrylic acid (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0209] AA: acrylic acid (manufactured by FUJIFILM Wako Pure Chemical Corporation, "Special Grade")

[0210] (Monomer B1)

[0211] PEG(9)MA: methoxypolyethylene glycol (9) monomethacrylate [manufactured by SHIN-NYU SEIKA KAGAKU KOGYO CO., LTD., "M-90G"] (in formula (3), R6 = methyl, R 5 = methyl, p = 9, q = 0)

[0212] (Monomer B1)

[0213] PEG(23)MA: methoxypolyethylene glycol (23) monomethacrylate [manufactured by Shin-Nakamura Chemical Industries, Ltd., "M-230G"] (in formula (3), R 6 = methyl, R 5 = methyl, p = 23, q = 0)

[0214] (Monomer B1)

[0215] PEG(90)MA: methoxypolyethylene glycol (90) monomethacrylate [manufactured by Shin-Nakamura Chemical Industries, Ltd., "M-900G"] (in formula (3), R 6 = methyl, R 5 = methyl, p = 90, q = 0)

[0216] (Monomer B1)

[0217] PEG(20)PG(3)MA: methoxypolyethylene glycol (20) polypropylene glycol (3) monomethacrylate [manufactured by Shin-Nakamura Chemical Industries, Ltd., "M-0320PE"] (in formula (3), R 6 = methyl, R 5 = methyl, p = 20, q = 3)

[0218] (Monomer B1)

[0219] PEG(45)MA: methoxypolyethylene glycol (45) monomethacrylate [manufactured by Shin-Nakamura Chemical Industries, Ltd., "M-450G"] (in formula (3), R 6 = methyl, R 5 = methyl, p = 45, q = 0)

[0220] (Monomer B2)

[0221] HEMA: 2-hydroxyethyl methacrylate [manufactured by FUJIFILM Wako Pure Chemical Corporation] (in formula (3), R 6 = H, R 5 = methyl, p = 1, q = 0)

[0222] (Other)

[0223] PDEA: phenoxydioxyethylene acrylate [manufactured by Kyoeisha Chemical Co., Ltd., "Lightacrylate P2H-A"]

[0224] [Table 1]

[0225]

[0226] 3. Preparation of a semiconductive SWCNT dispersion liquid

[0227] [Examples 1 to 8]

[0228] To 30 mL of a 0.5 mass% aqueous solution of each of the copolymers shown in Table 1, which was prepared by dissolving the copolymer with ultrapure water (manufactured by Wako Pure Chemical Industries, Ltd.), 30 mg of a SWCNT mixture (NanoIntegris Corporation, "HiPco-Raw", average diameter: 0.8 to 1.2 nm, average length: 0.4 to 0.7 μm) synthesized by the HiPco method was added to obtain a mixture.

[0229] Then, the mixture was dispersed by an ultrasonic homogenizer (BRANSON, "450D") at an amplitude of 30% and 10°C for 10 minutes while stirring with a stirrer to obtain a separated SWCNT dispersion liquid of each of Examples 1 to 8. The kinds and contents of each component in the separated SWCNT dispersion liquid are shown in Table 2. The contents of the SWCNT mixture and the copolymer in the separated SWCNT dispersion liquid are shown in Table 2, and the content of the aqueous medium is the residue after removing the SWCNT mixture and the copolymer.

[0230] The obtained separated SWCNT dispersion liquid was subjected to centrifugal treatment using an ultracentrifuge (Hitachi Koki, Co., Ltd., "CS100GXII", rotor S50A) at a rotation speed of 50,000 rpm, a gravitational acceleration of 210 kG, and 20°C for 30 minutes. Thereafter, 80% of the supernatant was collected from the liquid surface without raising the precipitated sediment on a volume basis to obtain a semiconductive SWCNT dispersion liquid of each of Examples 1 to 8.

[0231] [Comparative Example 1]

[0232] A separated SWCNT dispersion liquid and a supernatant (semiconductive SWCNT dispersion liquid) of Comparative Example 1 were obtained in the same manner as in Example 1 except that the copolymer a was replaced with the copolymer f. The contents of the SWCNT mixture and the copolymer in the separated SWCNT dispersion liquid are shown in Table 2, and the content of the aqueous medium is the residue after removing the SWCNT mixture and the copolymer.

[0233] 4. Evaluation

[0234] [Evaluation of separation]

[0235] The absorbance was measured using a UV-Visible-NIR spectrophotometer ("UV-3600 Plus" manufactured by Shimadzu Corporation) capable of measuring visible light to infrared light. Thereafter, the ratio of the peak intensity of the absorption wavelength inherent to the semiconducting SWCNTs to the peak intensity of the absorption wavelength inherent to the metallic SWCNTs was taken as an evaluation value of the separation of the semiconducting SWCNTs. The higher the calculated value, the higher the semiconducting SWCNT separation can be evaluated, and if the value is 1.2 or more, the semiconducting SWCNT separation is sufficiently high. The results are shown in Table 2.

[0236] [Num 1]

[0237]

[0238] Note that the SWCNTs (HIPCO) used had an absorption wavelength inherent to semiconducting SWCNTs around 730 nm and an absorption wavelength inherent to metallic SWCNTs around 480 nm.

[0239] [Dispersion stability evaluation]

[0240] The dispersion state of the semiconducting SWCNTs in the semiconducting SWCNT dispersion liquid after being left at room temperature of 25°C for 2 weeks was evaluated in accordance with the following evaluation criteria, and the results are shown in Table 2.

[0241] (Evaluation criteria)

[0242] A: Aggregates could not be confirmed by visual observation.

[0243] B: Several (less than 6) aggregates could be confirmed by visual observation.

[0244] C: A large number of aggregates could be confirmed by visual observation.

[0245] [Table 2]

[0246]

[0247] As shown in Table 2, in Examples 1 to 8, compared to Comparative Example 1, high separation of semiconducting SWCNTs and dispersion stability of semiconducting SWCNTs in the semiconducting SWCNT dispersion liquid could be well balanced.

[0248] Industrial applicability

[0249] As shown in the above description, according to the method for producing a semiconducting SWCNT dispersion liquid of the present application, high separation of semiconducting SWCNTs and dispersion stability of semiconducting SWCNTs in the semiconducting SWCNT dispersion liquid can be well balanced, and thus an improvement in the quality of an ink containing semiconducting SWCNTs can be expected.

Claims

1. A method for producing a semiconductor single-walled carbon nanotube dispersion liquid, the method for producing comprising the following steps: a step of preparing a separated single-walled carbon nanotube dispersion liquid containing a single-walled carbon nanotube, an aqueous medium, and a polymer, the single-walled carbon nanotube containing a semiconductor single-walled carbon nanotube and a metallic single-walled carbon nanotube; and a step of collecting a supernatant containing the semiconductor single-walled carbon nanotube from the separated single-walled carbon nanotube dispersion liquid after centrifuging the separated single-walled carbon nanotube dispersion liquid, the polymer is a copolymer containing a structural unit A derived from a monomer represented by formula (1) below and a structural unit B derived from a monomer represented by formula (3) below, the content of the structural unit B in all the structural units of the copolymer being 70% by mass or more and less than 100% by mass, CH2=CR 0 -COOM (1) In formula (1), R 0 represents a hydrogen atom or a methyl group; M represents any one of a hydrogen atom, a metal atom, and a group of a structure represented by formula (2) shown below. In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group; CH2=CR 5 -COO- (EO) p - (PO) q -R 6 (3) In formula (3), R 5 represents a hydrogen atom or a methyl group; R 6 represents a hydrogen atom or a hydrocarbon group having 1 or more and 5 or less carbon atoms, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents the average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents the average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

2. The method for producing a semiconductor single-walled carbon nanotube dispersion liquid according to claim 1, wherein the content of the structural unit A in all the structural units of the copolymer is more than 0% by mole and 90% by mole or less.

3. The method for producing a semiconductor single-walled carbon nanotube dispersion liquid according to claim 1 or 2, wherein the content of the structural unit B in all the structural units of the copolymer is 10% by mole or more and less than 100% by mole.

4. The method for producing a semiconductor single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 3, wherein the terminal structure R of the monomer represented by the formula (3) 6 is a hydrogen atom or a methyl group.

5. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 4, wherein In the formula (1), R 0 is a methyl group.

6. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 5, wherein In the formula (3), R 6 is a hydrocarbon group having 1 or more and 5 or less carbon atoms.

7. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 6, wherein the content of the structural unit A in all the structural units of the copolymer is more than 0% by mass and 20% by mass or less.

8. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 7, wherein the molar ratio of the structural unit A to the structural unit B in the copolymer, i.e., A / B, is more than 0 and 30 or less.

9. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 8, wherein the mass ratio of the structural unit A to the structural unit B in the copolymer, i.e., A / B, is more than 0 and 0.4 or less.

10. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 9, wherein the combination of the structural unit B1 in which the average addition mole number p of ethylene oxide is 4 or more and 120 or less and the structural unit B2 in which the average addition mole number p of ethylene oxide is 1 or more and less than 4.

11. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to claim 10, wherein the molar ratio of the structural unit B1 to the structural unit B2 in the copolymer, i.e., B1 / B2, is 0.01 or more and 0.5 or less.

12. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to claim 10, wherein the molar ratio of the structural unit B1 to the structural unit B2 in the copolymer, i.e., B1 / B2, is 0.03 or more and 0.4 or less.

13. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to claim 10, wherein the mass ratio of the structural unit B1 to the structural unit B2 in the copolymer, i.e., B1 / B2, is 0.1 or more and 5 or less.

14. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to claim 10, wherein the mass ratio of the structural unit B1 to the structural unit B2 in the copolymer, i.e., B1 / B2, is 0.2 or more and 3 or less.

15. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 14, wherein in formula (3), p is 1 or more and 90 or less.

16. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 15, wherein in formula (3), q is 0 or more and 30 or less.

17. The method for producing a semiconductive single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 16, wherein the weight average molecular weight of the copolymer is 1,000 or more and 250,000 or less.

18. The method for producing a semiconductor single-walled carbon nanotube dispersion liquid according to any one of claims 1 to 17, wherein The average diameter of the single-walled carbon nanotubes used in the production of the separated single-walled carbon nanotube dispersion is 0.5 nm or more and 3 nm or less.

19. A method for producing semiconductor-type single-walled carbon nanotubes, the method comprising a step of filtering a semiconductor-type single-walled carbon nanotube dispersion obtained by the method for producing a semiconductor-type single-walled carbon nanotube dispersion according to any one of claims 1 to 18, and collecting semiconductor-type single-walled carbon nanotubes.

20. A method for producing semiconductor-type single-walled carbon nanotubes, the method comprising the following steps: a step of drying a semiconductor-type single-walled carbon nanotube dispersion obtained by the method for producing a semiconductor-type single-walled carbon nanotube dispersion according to any one of claims 1 to 18 to obtain a mixture containing semiconductor-type single-walled carbon nanotubes and the copolymer; and a step of removing the copolymer from the mixture and collecting semiconductor-type single-walled carbon nanotubes.

21. A method for separating semiconductor-type single-walled carbon nanotubes from metal-type single-walled carbon nanotubes, the method comprising: a step of producing a separated single-walled carbon nanotube dispersion containing single-walled carbon nanotubes, an aqueous medium, and a polymer, the single-walled carbon nanotubes containing semiconductor-type single-walled carbon nanotubes and metal-type single-walled carbon nanotubes; and a step of collecting a supernatant containing the semiconductor-type single-walled carbon nanotubes from the separated single-walled carbon nanotube dispersion subjected to centrifugal separation, the polymer being a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below, the content of the structural unit B in all the structural units of the copolymer being 70% by mass or more and less than 100% by mass, CH2=CR 0 -COOM (1) In formula (1), R 0 represents a hydrogen atom or a methyl group; M represents any one of a hydrogen atom, a metal atom, and a group of a structure represented by formula (2) shown below. In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group; CH2=CR 5 -COO- (EO) p - (PO) q -R 6 (3) In formula (3), R 5 represents a hydrogen atom or a methyl group; R 6 represents a hydrogen atom or a hydrocarbon group having 1 or more and 5 or less carbon atoms, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents the average addition mole number of ethyleneoxy groups, and is 1 or more and 120 or less, and q represents the average addition mole number of propyleneoxy groups, and is 0 or more and 50 or less.

22. The method for separating semiconductor-type single-wall carbon nanotubes from metal-type single-wall carbon nanotubes according to claim 21, wherein, In the formula (1), R 0 is a methyl group.

23. The method of separating semiconductive single-wall carbon nanotubes from metallic single-wall carbon nanotubes according to claim 21 or 22, wherein, the terminal structure R of the monomer represented by the formula (3) 6 is a hydrogen atom or a methyl group.

24. The method of separating semiconductive single-wall carbon nanotubes from metallic single-wall carbon nanotubes according to any one of claims 21 to 23, wherein, In the formula (3), R 6 is a hydrocarbon group having 1 or more and 5 or less carbon atoms.

25. A method for producing an ink containing semiconductor-type single-walled carbon nanotubes, the method comprising the method according to any one of claims 1 to 24 as a step.

26. An ink containing semiconductor-type single-walled carbon nanotubes, the ink containing: semiconductor-type single-walled carbon nanotubes, at least one of an organic solvent and water, and a copolymer containing structural unit A derived from a monomer represented by formula (1) below and structural unit B derived from a monomer represented by formula (3) below, the content of the structural unit B in all the structural units of the copolymer being 70% by mass or more and less than 100% by mass, CH2=CR 0 -COOM (1) In formula (1), R 0 represents a hydrogen atom or a methyl group; M represents any one of a hydrogen atom, a metal atom, and a group of a structure represented by formula (2) shown below. In formula (2), R 1 , R 2 , R 3 , R 4 each independently represents a hydrogen atom, or an alkyl group having a carbon number of 1 or more and 2 or less, optionally having a hydroxyl group; CH2=CR 5 -COO- (EO) p - (PO) q -R 6 (3) In formula (3), R 5 represents a hydrogen atom or a methyl group; R 6 represents a hydrogen atom, or a hydrocarbon group having a carbon number of 1 or more and 5 or less, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, p represents an average addition mole number of the ethyleneoxy group, and is 1 or more and 120 or less, and q represents an average addition mole number of the propyleneoxy group, and is 0 or more and 50 or less.

27. The ink containing semiconductive single-walled carbon nanotubes according to claim 26, wherein, In the formula (1), R 0 is a methyl group.

28. The ink containing semiconducting single-walled carbon nanotubes according to claim 26 or 27, wherein, the terminal structure R of the monomer represented by the formula (3) 6 is a hydrogen atom or a methyl group.

29. The ink containing semiconducting single-walled carbon nanotubes according to any one of claims 26 to 28, wherein, In the formula (3), R 6 is a hydrocarbon group having 1 or more and 5 or less carbon atoms.

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