Inks including segment copolymer grafted pigments via azide chemistry

Patent metadata

Field	Value
Publication number	US-9441122-B2
Application number	US-201214373814-A
Country	US
Kind code	B2
Filing date	Jan 26, 2012
Priority date	Jan 26, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Pigment based inks are provided. The inks include a non-polar carrier fluid; and a surface-functionalized pigment particle including a nitrogen-inked moiety to the surface of the pigment particle through a nitrogen link at one end of the nitrogen-linked moiety and a segment copolymer having at least two blocks attached at another end, the pigment particle suspended in the non-polar carrier fluid. A combination of an electronic display and an electronic ink employing the pigment and a process for making the pigment-based inks are also provided.

First claim

What is claimed is:

1. Pigment based inks including:
a non-polar carrier fluid; and
a surface-functionalized pigment particle including a nitrogen-linked moiety to the surface of the pigment particle through a nitrogen link at one end of the nitrogen-linked moiety and a segment copolymer having at least two blocks attached at another end, wherein the segment copolymer has a formula selected from the group consisting of segment copolymer 1, segment copolymer 2, and segment copolymer 3, as shown below:

wherein,
L 1 , L 2 , and L 3 are each independently a covalent bond or chemical structure providing a covalent bond between different blocks selected from the group consisting of C—C, C═C, C═N, C≡C, and N≡N;
SG 1 and SG 2 each independently represent a solubilizing and sterically bulky group, which helps to improve the solubility of the polymer and stabilize the colorant particles, selected from the group consisting of alkyl groups, alkoxy groups, branched alkyl groups, branched alkoxy groups, aliphatic esters, branched aliphatic esters, substituted phenyl groups, and macromolecular monomers;
FG represents a functional group that provides charging sites to pigment surfaces, selected from acidic functional groups and basic groups;
x, y and z are each independently an integer between 1 and about 5,000; and n is an integer between 2 and about 100,
wherein the pigment particle is suspended in the non-polar carrier fluid.

2. The inks of claim 1 , wherein the non-polar carrier fluid is a non-polar solvent selected from the group consisting of hydrocarbons, halogenated hydrocarbons, partially halogenated hydrocarbons, and siloxanes.

3. The inks of claim 1 , wherein the pigment particle is selected from the group consisting of black pigment particles, yellow pigment particles, magenta pigment particles, red pigment particles, violet pigment particles, cyan pigment particles, blue pigment particles, green pigment particles, orange pigment particles, brown pigment particles, and white pigment particles.

4. The inks of claim 1 , wherein FG is selected from the group consisting of primary amines, secondary amines, tertiary amines, amides, nitriles, isonitriles, cyanates, isocyanates, thiocyanates, isothiocyanates, azides, thiols, thiolates, sulfides, sulfinates, sulfonates, phosphates, hydroxyls, alcoholates, phenolates, carbonyls, carboxylates, phosphines, phosphine oxides, phosphonic acids, phosphoramides, and phosphates.

5. The inks of claim 1 , wherein at least one of SG 1 and SG 2 comprise the macromolecule monomer selected from the group consisting of

wherein m is an integer from 1 to 5,000.

6. The inks of claim 1 , wherein one or both of SG 1 and SG 2 comprises

wherein,
R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from the group consisting of C1-C30 alkyl, C1-C30 alkenyl, C1-C30 alkynyl, C1-C30 aryl, C1-C30 alkoxy, C1-C30 phenoxy, C1-C30 thioalkyl, C1-C30 thioaryl, C(O)OR 6 , N(R 7 )(R 8 ), C(O)N(R 9 )(R 10 ), F, Cl, Br, NO 2 , CN, acyl, carboxylate and hydroxy, wherein R 6 , R 7 , R 8 , R 9 and R 10 are each independently selected from the group consisting of hydrogen, C1-C30 alkyl and C1-C30 aryl, and wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 may or may not be identical.

7. The inks of claim 1 , further including a charge director, wherein the charge director is a small molecule or polymer that is capable of forming reverse micelles in the non-polar carrier fluid.

8. In combination, an electronic display and an electronic ink, wherein the electronic display includes:
a first electrode;
a second electrode; and
a display cell having a recess defined by a dielectric material, the first electrode, and the second electrode, the display cell containing the electronic ink; and wherein the electronic ink includes:
a non-polar carrier fluid; and
a surface-functionalized pigment particle including a nitrogen-linked moiety to the surface of the pigment particle through a nitrogen link at one end of the nitrogen-linked moiety and a segment copolymer having at least two blocks attached at another end, wherein the segment copolymer has a formula selected from the group consisting of segment copolymer 1, segment copolymer 2, and segment copolymer 3, as shown below:

wherein,
L 1 , L 2 , and L 3 are each independently a covalent bond or chemical structure providing a covalent bond between different blocks selected from the group consisting of C—C, C═C, C═N, C≡C, and N≡N;
SG 1 and SG 2 each independently represent a solubilizing and sterically bulky group, which helps to improve the solubility of the polymer and stabilize the colorant particles, selected from the group consisting of alkyl groups, alkoxy groups, branched alkyl groups, branched alkoxy groups, aliphatic esters, branched aliphatic esters, substituted phenyl groups, and macromolecular monomers;
FG represents a functional group that provides charging sites to pigment surfaces, selected from acidic functional groups and basic groups;
x, y and z are each independently an integer between 1 and about 5,000; and n is an integer between 2 and about 100,
wherein the pigment particle is suspended in the non-polar carrier fluid.

9. The combination of claim 8 , wherein the electronic display includes a plurality of display cells in a stacked configuration, associated first electrodes and second electrodes, and a plurality of electronic inks of different colors, each display cell containing an electronic ink of a different color.

10. The combination of claim 8 , wherein the non-polar carrier fluid is a non-polar solvent selected from the group consisting of hydrocarbons, halogenated hydrocarbons, partially halogenated hydrocarbons, and siloxanes.

11. The combination of claim 8 , wherein the colored pigment is a colored particle having a size ranging from 1 nm to 10 μm and is selected from the group consisting of black pigment particles, yellow pigment particles, magenta pigment particles, red pigment particles, violet pigment particles, cyan pigment particles, blue pigment particles, green pigment particles, orange pigment particles, brown pigment particles, and white pigment particles.

12. The combination of claim 8 , further including a charge director, wherein the charge director is a small molecule or polymer that is capable of forming reverse micelles in the non-polar carrier fluid.

13. A method for making a nitrogen-linked surface functionalized pigment particle including:
providing an azide;
causing the azide to initiate polymerization of a first block monomer to give a first block azide living polymer;
adding a second monomer to the first block living polymer to give a two-block azide living copolymer and form a first segment;
forming at least one additional segment by adding, in any order, a first block monomer and a second block monomer to form a two-block living segment copolymer; wherein the segment copolymer has a formula selected from the group consisting of segment copolymer 1, segment copolymer 2, and segment copolymer 3, as shown below:

wherein,
L 1 , L 2 , and L 3 are each independently a co

Assignees

• Zhou Zhang-Lin
• Liu Qin
• Hewlett Packard Development Co Lp

Inventors

• Zhou Zhang-Lin
• Liu Qin

Classifications

• C09D11/033

  characterised by the solvent · CPC title

• C09D11/107 Primary

  from unsaturated acids or derivatives thereof · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title

• C09D11/037

  characterised by the pigment · CPC title

• G02F1/133348

  Charged particles addressed liquid crystal cells, e.g. controlled by an electron beam · CPC title