Highly branched polymer and dispersant for carbon nanotubes

Patent metadata

Field	Value
Publication number	US-10138323-B2
Application number	US-201214119798-A
Country	US
Kind code	B2
Filing date	May 25, 2012
Priority date	May 25, 2011
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A highly branched polymer comprising repeating units which each have an acid group such as sulfo group, said repeating units being represented by formula [1] or the like, and a dispersant for carbon nanotubes (CNTs) which comprises the highly branched polymer can disperse CNTs in a medium such as an organic solvent to the individual sizes and can yield thin films having improved conductivity.

In formula [1], any one of A 1 to A 5 is a sulfo group, and the others are each a hydrogen atom.

First claim

The invention claimed is:

1. A highly branched polymer characterized by comprising repeating units of formula (1) or formula (2) below

wherein
Ar 1 to Ar 3 are each independently a divalent organic group of any one of formulas (3) to (7) below

in which R 5 to R 38 are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, an alkoxy group of 1 to 5 carbons which may have a branched structure, or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof;
Z 1 and Z 2 are each independently a hydrogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, or a monovalent organic group of any one of formulas (8) to (11) below

in which R 39 to R 62 are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, a phenyl group, OR 63 , COR 63 , NR 63 R 64 , COOR 65 (R 63 and R 64 being each independently a hydrogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, or a phenyl group; and R 65 being an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, or a phenyl group), or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof, with the proviso that Z 1 and Z 2 are not both alkyl groups; and R 1 to R 4 in formula (2) are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, an alkoxy group of 1 to 5 carbons which may have a branched structure, or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof;
with the proviso that at least one type of acidic group selected from among carboxyl groups, sulfo groups, phosphoric acid groups, phosphonic acid groups, and salts thereof is present on at least one aromatic ring of the repeating unit of formula (1) or (2).

2. The highly branched polymer according to claim 1 , wherein the repeating units are of formula (12) below

wherein R 5 to R 8 are hydrogen atoms, carboxyl groups, sulfo groups, phosphoric acid groups, phosphonic acid groups, or salts thereof; and Z 1 and Z 2 are as defined above.

3. The highly branched polymer according to claim 1 or 2 , wherein Z 2 is a hydrogen atom.

4. The highly branched polymer according to claim 3 , wherein Z 1 is a hydrogen atom, a thienyl group, or a monovalent organic group of formula (8).

5. The highly branched polymer according to claim 1 , wherein the acidic group is a sulfo group or a salt thereof.

6. The highly branched polymer according to claim 1 which has a polystyrene-equivalent weight-average molecular weight, as measured by gel permeation chromatography, of from 1,000 to 2,000,000.

7. A film-forming composition containing the highly branched polymer according to claim 1 .

8. A film containing the highly branched polymer according to claim 1 .

9. A carbon nanotube dispersant comprising the highly branched polymer according to claim 1 .

10. A composition comprising the carbon nanotube dispersant of claim 9 and carbon nanotubes.

11. The composition according to claim 10 , wherein the carbon nanotube dispersant adheres to surfaces of the carbon nanotubes and forms composite bodies.

12. The composition according to claim 10 or 11 which further comprises an organic solvent.

13. The composition according to claim 12 , wherein the carbon nanotubes are individually dispersed in the organic solvent.

14. The composition according to claim 12 , wherein the composite bodies are individually dispersed in the organic solvent.

15. The composition according to claim 10 , wherein the carbon nanotubes are of at least one type selected from among single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes.

16. The composition according to claim 12 which further comprises a crosslinking agent that is soluble in the organic solvent.

17. The composition according to claim 16 which further comprises an acid and/or an acid generator.

18. A thin-film obtained from the composition according to claim 10 .

19. A cured film obtained by heat-treating a thin-film obtained from carbon nanotubes, an organic solvent, a crosslinking agent which is soluble in said organic solvent, and a carbon nanotube dispersant comprising a highly branched polymer characterized by comprising repeating units of formula (1) or formula (2) below

wherein
Ar 1 to Ar 3 are each independently a divalent organic group of any one of formulas (3) to (7) below

in which R 5 to R 38 are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, an alkoxy group of 1 to 5 carbons which may have a branched structure, or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof;
Z 1 and Z 2 are each independently a hydrogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, or a monovalent organic group of any one of formulas (8) to (11) below

in which R 39 to R 62 are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, a phenyl group, OR 63 , COR 63 , NR 63 R 64 , COOR 65 (R 63 and R 64 being each independently a hydrogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, or a phenyl group; and R 65 being an alkyl group of 1 to 5 carbons which may have a branched structure, a haloalkyl group of 1 to 5 carbons which may have a branched structure, or a phenyl group), or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof, with the proviso that Z 1 and Z 2 are not both alkyl groups; and R 1 to R 4 in formula (2) are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons which may have a branched structure, an alkoxy group of 1 to 5 carbons which may have a branched structure, or a carboxyl group, sulfo group, phosphoric acid group, phosphonic acid group or salt of any thereof;
with the proviso that at least one type of acidic group selected from among carboxyl groups, sulfo groups, phosphoric acid groups, phosphonic acid groups, and salts thereof is present on at least one aromatic ring of the repeating unit of formula (1) or (2).

Assignees

• Saito Daigo
• Hatanaka Tatsuya
• Nissan Chemical Ind Ltd

Inventors

• Saito Daigo
• Hatanaka Tatsuya

Classifications

• C08G12/40

  Chemically modified polycondensates · CPC title

• H01B1/24

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title

• C01B32/176

  Cutting · CPC title

• C08G73/026

  Wholly aromatic polyamines · CPC title

• C08K3/041

  Carbon nanotubes · CPC title