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EP-4741340-A1 - MULTILAYER CARBON NANOTUBE ASSEMBLY, MULTILAYER CARBON NANOTUBE DISPERSION LIQUID, CONDUCTIVE MATERIAL, ELECTRODE, SECONDARY BATTERY, PLANAR ASSEMBLY, FILTER, ELECTROMAGNETIC WAVE SHIELD, AND PELLICLE FOR EXTREME ULTRAVIOLET RAYS

EP4741340A1EP 4741340 A1EP4741340 A1EP 4741340A1EP-4741340-A1

Abstract

Provided are a multi-walled carbon nanotube assembly having high conductivity and good dispersibility in a dispersion medium, as well as a multi-walled carbon nanotube dispersion liquid, a conductive material, an electrode, a secondary battery, a planar assembly, a filter, an electromagnetic wave shielding, and a pellicle for extreme ultraviolet rays. A multi-walled carbon nanotube assembly, containing multi-walled carbon nanotubes having a maximum length of 1,000 µm to 30,000 µm, and Fe atoms, in which the content ratio of Fe atoms to a total mass of the assembly is 0.5 mass% or more and less than 10 mass%; as well as a multi-walled carbon nanotube dispersion liquid, a conductive material, an electrode, a secondary battery, a planar assembly, a filter, an electromagnetic wave shielding, and a pellicle for extreme ultraviolet rays.

Inventors

  • ARIMURA, TAKASHI
  • AKATSU, MITSUTOSHI
  • YASHIRO, ARIHIRO

Assignees

  • Sumitomo Chemical Company, Limited

Dates

Publication Date
20260513
Application Date
20240613

Claims (20)

  1. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a maximum length of 1,000 µm to 30,000 µm, and Fe atoms, wherein a content ratio of Fe atoms to a total mass of the assembly is 0.5 mass% or more and less than 10 mass%.
  2. The multi-walled carbon nanotube assembly according to claim 1, which is a conductive auxiliary agent.
  3. A multi-walled carbon nanotube dispersion liquid comprising the multi-walled carbon nanotube assembly according to claim 1 or 2, and a dispersion medium.
  4. A conductive material comprising the multi-walled carbon nanotube assembly according to claim 1 or 2.
  5. The multi-walled carbon nanotube dispersion liquid according to claim 3, which is an ink composition for formation of a lithium battery negative electrode.
  6. An electrode comprising an electrode active material, and the conductive material according to claim 4.
  7. A secondary battery comprising the electrode according to claim 6.
  8. A composition comprising the multi-walled carbon nanotube assembly according to claim 1 or 2, and at least one selected from the group consisting of a resin, a ceramic, and concrete.
  9. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a tensile strength of 10 MPa to 100 MPa, and Fe atoms, wherein a content ratio of Fe atoms to a total mass of the assembly is 0.5 mass% or more and less than 10 mass%.
  10. The multi-walled carbon nanotube assembly according to claim 9, which is a conductive auxiliary agent.
  11. A multi-walled carbon nanotube dispersion liquid comprising the multi-walled carbon nanotube assembly according to claim 9 or 10, and a dispersion medium.
  12. A conductive material comprising the multi-walled carbon nanotube assembly according to claim 9 or 10.
  13. The multi-walled carbon nanotube dispersion liquid according to claim 11, which is an ink composition for formation of a lithium battery negative electrode.
  14. An electrode comprising an electrode active material, and the conductive material according to claim 12.
  15. A secondary battery comprising the electrode according to claim 14.
  16. A composition comprising the multi-walled carbon nanotube assembly according to claim 9 or 10, and at least one selected from the group consisting of a resin, a ceramic, and concrete.
  17. A composition comprising: a multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes and Fe atoms, wherein a content ratio of Fe atoms to a total mass of the assembly is 0.5 mass% or more and less than 10 mass%; and at least one selected from the group consisting of a dispersion medium, a resin, a ceramic, and concrete.
  18. A multi-walled carbon nanotube dispersion liquid comprising multi-walled carbon nanotubes having a tensile strength of 10 MPa to 100 MPa, and a dispersion medium.
  19. A planar assembly comprising the multi-walled carbon nanotube assembly according to claim 1, 2, 9 or 10.
  20. A filter comprising the planar assembly according to claim 19.

Description

Technical Field The present disclosure relates to a multi-walled carbon nanotube assembly, a multi-walled carbon nanotube dispersion liquid, a conductive material, an electrode, a secondary battery, a planar assembly, a filter, an electromagnetic wave shielding, and a pellicle for extreme ultraviolet rays. Background Art Carbon nanotubes have good mechanical and electronic characteristics, and are expected to be used for various purposes. As carbon nanotubes (which may be hereinafter referred to as "CNT"), single-walled carbon nanotubes (which may be hereinafter referred to as "SWCNT") and multi-walled carbon nanotubes (which may be hereinafter referred to as "MWCNT") that are several µm to several tens of µm in length are known. SWCNT is a seamless cylindrical tube formed from a single layer of graphene, has a high specific surface area, thus can be expected to have high conductivity, and therefore attracts attention as a conductive auxiliary agent. On the other hand, MWCNT is formed such that a plurality of layers of concentric cylindrical tubes overlap one another. Some MWCNT has as many as several tens of layers. MWCNT is larger in diameter of the cylindrical tube than SWCNT and smaller in specific surface area than SWCNT, and therefore has slightly better handleability over SWCNT, but has a problem that it is difficult to exhibit conductivity as high as that of SWCNT. CNT that is several µm to several tens of µm in length is powdery, and is mainly composed of carbon. Therefore, CNT is typically difficult to handle, and has poor dispersibility in a dispersion medium. In recent years, longer CNT, specifically long-fiber MWCNT having a length in the order of several mm, has attracted attention. Long-fiber MWCNT has a low specific surface area, but is expected to have higher conductivity over short MWCNT because of the large length. Long-fiber MWCNT is easier to handle over powdery CNT. Long fiber MWCNT has been heretofore difficult to produce, but is expected to be more easily obtained by virtue of recent studies made on production techniques. For example, a method has been proposed in which a plurality of CNT is collected in a state of being aligned in a longitudinal direction, thereby obtaining an elongated CNT assembled line or CNT assembled line bundle (see, for example, Patent Literature 1). Patent Literature 1 discloses a technique capable of setting the length of a CNT assembled line to 10 cm or more. Citation List Patent Literature Patent Literature 1: International Publication No. WO 2020/138379 Summary of Invention Problems to be Solved by Invention A CNT assembly obtained by the technique disclosed in Patent Literature 1 includes an assembly of long fibers in which CNT fibers are aligned. Patent Literature 1 does not describe the dispersibility in a dispersion medium, which is important for the application of CNT. A problem to be solved by an embodiment of the present disclosure is to provide a multi-walled carbon nanotube assembly having high conductivity and good dispersibility in a dispersion medium, as well as a conductive material, an electrode, a secondary battery, and a planar assembly, each containing the multi-walled carbon nanotube assembly. A problem to be solved by another embodiment of the present disclosure is to provide a multi-walled carbon nanotube dispersion liquid containing a multi-walled carbon nanotube assembly having high conductivity. A problem to be solved by yet another embodiment of the present disclosure is to provide a planar assembly containing multi-walled carbon nanotube powder, and a filter, an electromagnetic wave shielding, and a pellicle for extreme ultraviolet rays, each including the planar assembly. Means to Solve the Problems <1> A multi-walled carbon nanotube assembly comprising: multi-walled carbon nanotubes having a maximum length of 1,000 µm to 30,000 µm; and Fe atoms, wherein a content ratio of Fe atoms to a total mass of the assembly is 0.5 mass% or more and less than 10 mass%.<2> The multi-walled carbon nanotube assembly according to <1>, which is a conductive auxiliary agent.<3> A multi-walled carbon nanotube dispersion liquid comprising the multi-walled carbon nanotube assembly according to <1> or <2>, and a dispersion medium.<4> A conductive material comprising the multi-walled carbon nanotube assembly according to <1> or <2>.<5> The multi-walled carbon nanotube dispersion liquid according to <3>, which is an ink composition for formation of a lithium battery negative electrode.<6> An electrode comprising an electrode active material, and the conductive material according to <4>.<7> A secondary battery comprising the electrode according to <6>.<8> A composition comprising the multi-walled carbon nanotube assembly according to <1> or <2>, and at least one selected from the group consisting of a resin, a ceramic, and concrete.<9> A multi-walled carbon nanotube assembly comprising: multi-walled carbon nanotubes having a tensile strength of 10 MPa t