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EP-4741341-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

EP4741341A1EP 4741341 A1EP4741341 A1EP 4741341A1EP-4741341-A1

Abstract

There are provided a multi-walled carbon nanotube assembly having high conductivity, 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, 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, each including multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-based particle size distribution obtained by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.004% by mass, and having a rate of change in transmittance of 0.3%/hour or less as measured by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.

Inventors

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

Assignees

  • Sumitomo Chemical Company, Limited

Dates

Publication Date
20260513
Application Date
20240613

Claims (17)

  1. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-based particle size distribution obtained by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.004% by mass, and having a rate of change in transmittance of 0.3%/hour or less as measured by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  2. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a scattering intensity ratio S1/S2 of 90 or more, which is a ratio of a scattering intensity S1 at a scattering vector magnitude q = 0.2 nm -1 to a scattering intensity S2 at a scattering vector magnitude q = 0.8 nm -1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  3. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a scattering intensity ratio S3/S4 of 10 or less, which is a ratio of a scattering intensity S3 at a scattering vector magnitude q = 0.02 nm -1 to a scattering intensity S4 at a scattering vector magnitude q = 0.08 nm -1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  4. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-based particle size distribution obtained by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.004% by mass, and having a rate of change in transmittance of 0.3%/hour or less as measured by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass, and having a scattering intensity ratio S1/S2 of 90 or more, which is a ratio of a scattering intensity S1 at a scattering vector magnitude q = 0.2 nm -1 to a scattering intensity S2 at a scattering vector magnitude q = 0.8 nm -1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  5. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-based particle size distribution obtained by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.004% by mass, and having a rate of change in transmittance of 0.3%/hour or less as measured by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass, and having a scattering intensity ratio S3/S4 of 10 or less, which is a ratio of a scattering intensity S3 at a scattering vector magnitude q = 0.02 nm -1 to a scattering intensity S4 at a scattering vector magnitude q = 0.08 nm -1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  6. A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a scattering intensity ratio S1/S2 of 90 or more, which is a ratio of a scattering intensity S1 at a scattering vector magnitude q = 0.2 nm -1 to a scattering intensity S2 at a scattering vector magnitude q = 0.8 nm -1 in a scattering profile obtained by a small-angle X-ray scattering method, and having a scattering intensity ratio S3/S4 of 10 or less, which is a ratio of a scattering intensity S3 at a scattering vector magnitude q = 0.02 nm -1 to a scattering intensity S4 at a scattering vector magnitude q = 0.08 nm -1 in the scattering profile, when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.
  7. The multi-walled carbon nanotube assembly according to any one of claims 1 to 6, wherein a maximum length of the multi-walled carbon nanotubes is 1000 µm to 30000 µm.
  8. The multi-walled carbon nanotube assembly according to any one of claims 1 to 6, which is a conductive auxiliary agent.
  9. A multi-walled carbon nanotube dispersion liquid comprising the multi-walled carbon nanotube assembly according to any one of claims 1 to 6, and a dispersion medium.
  10. A conductive material comprising the multi-walled carbon nanotube assembly according to any one of claims 1 to 6.
  11. An electrode comprising an electrode active material and the conductive material according to claim 10.
  12. A secondary battery comprising the electrode according to claim 11.
  13. A composition comprising the multi-walled carbon nanotube assembly according to any one of claims 1 to 6, and at least one selected from the group consisting of resin, ceramic, and concrete.
  14. A planar assembly comprising the multi-walled carbon nanotube assembly according to any one of claims 1 to 6.
  15. A filter comprising the planar assembly according to claim 14.
  16. An electromagnetic wave shielding comprising the planar assembly according to claim 14.
  17. A pellicle for extreme ultraviolet rays comprising the planar assembly according to claim 14.

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 (also referred to as "CNTs") are substances having a cylindrical structure formed by rolling graphene sheets, in which carbon atoms are arranged in a hexagonal honeycomb pattern, into a tubular shape. Due to their excellent characteristics such as conductivity, thermal conductivity, and heat resistance, CNTs are expected to be applied to various electronic materials, including electrode materials for energy storage devices. Basically, CNTs are broadly classified into single-walled carbon nanotubes (also referred to as "SWCNTs") formed from a single layer of graphene sheet, and multi-walled carbon nanotubes (also referred to as "MWCNTs") formed from multiple layers of graphene sheets. MWCNTs have the advantage of superior thermal stability and chemical stability compared to SWCNTs, and in recent years, attempts have been made to enhance the characteristics of MWCNTs more effectively. For example, Patent Literature 1 discloses CNTs having two or more layers of coaxial tubes of graphene sheets in which carbon atoms are arranged in a hexagonal honeycomb pattern, wherein, in the MWCNTs, the diameter of the outermost layer based on image observation with a transmission electron microscope is 3 nm or more and 15 nm or less, and the length based on image observation with a scanning electron microscope is 1.0 mm or more. According to the MWCNTs disclosed in Patent Literature 1, the applicability to materials requiring high conductivity, high thermal conductivity, and the like is considered to be enhanced. Citation List Patent Literature Patent Literature 1: Japanese Patent Laid-Open No. 2020-180028 Summary of Invention Problems to be Solved by Invention In recent years, interest in the usefulness of MWCNTs as electronic materials has been increasing. For example, when MWCNTs are used as electrode materials such as conductive auxiliary agents, high conductivity can be imparted to the electrodes, and thus an improvement in the performance of energy storage devices can be expected. However, conventional MWCNTs, including the MWCNTs disclosed in Patent Literature 1, still have room for improvement in terms of the effect of enhancing conductivity when used in electrodes as electrode materials. The present disclosure has been made in view of the above circumstances. A problem to be solved by one embodiment of the present disclosure is to provide a multi-walled carbon nanotube assembly having high conductivity. Problems to be solved by other embodiments of the present disclosure are to provide a multi-walled carbon nanotube dispersion liquid, a conductive material, an electrode, a secondary battery, and a planar assembly, each comprising the multi-walled carbon nanotube assembly described above. In addition, problems to be solved by other embodiments of the present disclosure are to provide a filter, an electromagnetic wave shielding, and a pellicle for extreme ultraviolet rays, each comprising the planar assembly described above. Means to Solve the Problems Specific means for solving the above problems include the following aspects. [1] A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-based particle size distribution obtained by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.004% by mass, and having a rate of change in transmittance of 0.3%/hour or less as measured by a centrifugal sedimentation method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.[2] A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a scattering intensity ratio S1/S2 of 90 or more, which is a ratio of a scattering intensity S1 at a scattering vector magnitude q = 0.2 nm-1 to a scattering intensity S2 at a scattering vector magnitude q = 0.8 nm-1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.[3] A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a scattering intensity ratio S3/S4 of 10 or less, which is a ratio of a scattering intensity S3 at a scattering vector magnitude q = 0.02 nm-1 to a scattering intensity S4 at a scattering vector magnitude q = 0.08 nm-1 in a scattering profile obtained by a small-angle X-ray scattering method when formed into an aqueous dispersion liquid having a concentration of 0.2% by mass.[4] A multi-walled carbon nanotube assembly comprising multi-walled carbon nanotubes having a median diameter of 80 nm or more in a volume-b