Surface-modified nanodiamond and method for producing surface-modified nanodiamond

Patent metadata

Field	Value
Publication number	US-12534374-B2
Application number	US-202017611613-A
Country	US
Kind code	B2
Filing date	Jun 3, 2020
Priority date	Jun 5, 2019
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

Provided are: a polyglycerin-chain surface-modified nanodiamond having excellent dispersibility in a low-polarity solvent; and a method of producing the polyglycerin-chain surface-modified nanodiamond. A surface-modified nanodiamond 1 includes a nanodiamond particle 2 and a surface-modifying group 3 that surface-modifies the nanodiamond particle 2, the surface-modifying group 3 having a polyglycerin chain in which a hydrogen atom of at least some of the hydroxyl groups in the polyglycerin chain is substituted by a monovalent organic group.

First claim

The invention claimed is:

1 . A surface-modified nanodiamond comprising a nanodiamond particle and a surface-modifying group that surface-modifies the nanodiamond particle, the surface-modifying group having a polyglycerin chain in which a hydrogen atom of at least one hydroxyl group in the polyglycerin chain is substituted by a monovalent organic group,
wherein the monovalent organic group is a group represented by Formula (1):
—X—R  (1)

where in Formula (1), X represents —C(═O)— or —C(═O)—NH—; R represents a monovalent organic group; and an atom bonded to X is a carbon atom.

2 . The surface-modified nanodiamond according to claim 1 , wherein the polyglycerin chain is bonded to the nanodiamond particle via a single bond or a divalent group.

3 . The surface-modified nanodiamond according to claim 2 , wherein the divalent group is an amino group (—NH—), an ether bond (—O—), an ester bond (—C(═O)O—), a phosphinic acid group (—PH(═O)O—), a sulfide bond (—S—), a carbonyl group (—C(═O)—), an amide group (—C(═O)—NH—), a urethane bond (—NH—C(═O)—O—), an imide bond (—C(═O)—NH—C(═O)—), a thiocarbonyl group (—C(═S)—), a siloxane bond (—Si—O—), a divalent hydrocarbon group, or a group in which two or more of those listed above are bonded (preferably a single bond, —NH—, —O—, —C(═O)O—, —PH(═O)O—, or —S—).

4 . The surface-modified nanodiamond according to claim 1 , wherein the surface-modifying group having a polyglycerin chain in which a hydrogen atom of at least one hydroxyl group in the polyglycerin chain is substituted by a monovalent organic group represented by Formula (1) is represented by Formula (2):
—Y—(C 3 H 6 O 2 )p-(C 3 H 5 O 2 R 1 )q-OR 2   (2)
where in Formula (2), p and q each represent an average degree of polymerization for a repeating unit in parentheses, where p is a value of 0 or greater, q is a value of 0 or greater, and p+q is a value of 1 or greater; R 1 represents a monovalent organic group; [—OR 2 ] represents a terminal of a polyglycerin chain, where R 2 represents a hydrogen atom or a monovalent organic group, and when R 2 is a hydrogen atom, q represents a value greater than 0; and Y represents a single bond or a divalent group, and a bond extending left from Y is bonded to an ND particle.

5 . The surface-modified nanodiamond according to claim 1 , wherein in Formula (1), R represents an alkyl group.

6 . The surface-modified nanodiamond according to claim 1 , wherein in Formula (1), R represents an alkyl group having from 1 to 18 carbons.

7 . The surface-modified nanodiamond according to claim 1 , wherein in Formula (1), R represents an ethyl group, a butyl group, or a hexyl group.

8 . The surface-modified nanodiamond according to claim 1 , having an absorption peak from around 1510 to 1540 cm −1 and an absorption peak from around 1700 to 1730 cm −1 in an FT-IR spectrum.

9 . The surface-modified nanodiamond according to claim 1 , having an absorption peak from around 1730 to 1750 cm −1 in an FT-IR spectrum.

10 . The surface-modified nanodiamond according to claim 1 , having a median size from 5 to 100 nm upon dispersing the surface-modified nanodiamond in at least one organic dispersion medium having a Hildebrand solubility parameter (δ) of 10 (cal/cm 3 ) 1/2 or less such that a content ratio of the surface-modified nanodiamond is 0.1 mass %.

11 . The surface-modified nanodiamond according to claim 1 , wherein a mass ratio of the nanodiamond particle to the surface-modifying group in the surface-modified nanodiamond is from 0.5 to 1.0.

12 . The surface-modified nanodiamond according to claim 1 , wherein a particle size (D50) of the surface-modified nanodiamond is 400 nm or less.

13 . The surface-modified nanodiamond according to claim 1 , wherein the nanodiamond particle includes a nanodiamond obtained by a detonation method.

14 . A method of producing the surface-modified nanodiamond according to claim 1 , the method comprising reacting a surface-modified nanodiamond (A) with at least one compound selected from the group consisting of an alcohol (B1), an isocyanate ester (B2), and a carboxylic acid chloride (B3),
the surface-modified nanodiamond (A) including a nanodiamond particle and a surface-modifying group that surface-modifies the nanodiamond particle, the surface-modifying group having a polyglycerin chain that contains a hydroxyl group.

15 . A nanodiamond dispersion composition including a dispersion medium and the surface-modified nanodiamond described in claim 1 , the surface-modified nanodiamond being dispersed in the dispersion medium.

16 . The nanodiamond dispersion composition according to claim 15 , wherein the dispersion medium contains a cyclic ether or a chain ketone.

17 . The nanodiamond dispersion composition according to claim 15 , wherein a content ratio of a nanodiamond particle in the nanodiamond dispersion composition is from 0.1 mass ppm to 10 mass %.

18 . The nanodiamond dispersion composition according to claim 15 , wherein an average dispersed particle size (D50) of the nanodiamond particle in the nanodiamond dispersion composition is 100 nm or less.

19 . The nanodiamond dispersion composition according to claim 15 , wherein a haze value of the nanodiamond dispersion composition is 5 or less.

Assignees

• Daicel Corp

Inventors

• Shiro Daisuke
• Kume Atsushi

Classifications

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C08G65/329

  with organic compounds · CPC title

• C08G65/22

  Cyclic ethers having at least one atom other than carbon and hydrogen outside the ring · CPC title

• C01B32/28 Primary

  After-treatment, e.g. purification, irradiation, separation or recovery · CPC title