Photo-thermally induced polymerization inhibitors for electrophoretic media

Patent metadata

Field	Value
Publication number	US-10585325-B2
Application number	US-201815904739-A
Country	US
Kind code	B2
Filing date	Feb 26, 2018
Priority date	Mar 9, 2017
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

An electrophoretic medium that may be incorporated into an electrophoretic display includes a dispersion that may be contained in a plurality of microcapsules or microcells or a polymeric continuous phase. The dispersion may include a non-polar fluid, a plurality of first charged particles; and an inhibitor of photo-thermally induced polymerization that inhibits potential cross-linking between the particles and/or the microcells or polymeric continuous phase. The inhibitor may be a compound having an unsaturated hydrocarbon ring and at least one of a hydroxyl group, a carbonyl group, and a nitroso group. The plurality of microcells or polymeric continuous phase and a coating of the particles may include a polymeric material that includes (meth)acrylates.

First claim

We claim:

1. An electrophoretic medium comprising a dispersion, the dispersion comprising:
(a) a non-polar fluid;
(b) a plurality of first charged particles; and
(c) an inhibitor of photo-thermally induced polymerization, wherein the inhibitor is selected from the group consisting of 2, 6-di-tert-butyl-p-cresol, tris (N-nitroso-N-phenylhydroxylamine) aluminum salt, 4,4′,4″-(1-methylpropanyl-3-ylidene)tris[6-tert-butyl-m-cresol], and 4,4′-butylidenebis(6-tert-butyl-m-cresol).

2. The electrophoretic medium of claim 1 , wherein the first charged particles comprise a polymeric coating containing (meth)acrylate groups.

3. The electrophoretic medium of claim 2 , wherein the dispersion is encapsulated within a plurality of microcells or polymeric continuous phase comprising a polymeric material containing (meth)acrylate groups.

4. The electrophoretic medium of claim 1 , wherein the dispersion is encapsulated.

5. The electrophoretic medium of claim 4 , wherein the dispersion is encapsulated within a plurality of microcells or polymeric continuous phase comprising a polymeric material containing (meth)acrylate groups.

6. The electrophoretic medium of claim 1 , further comprising a plurality of second charged particles dispersed in the non-polar fluid, wherein the first and second charged particles have opposite charges, and at least one of the first and second charged particles comprises a polymeric coating containing (meth)acrylate groups.

7. The electrophoretic medium of claim 6 , wherein the dispersion is encapsulated within a plurality of microcells or polymeric continuous phase comprising a polymeric material containing (meth)acrylate groups.

8. The electrophoretic medium of claim 1 , wherein the first charged particles comprise titania, carbon black, or copper chromite.

9. The electrophoretic medium of claim 1 , wherein the weight percent of the inhibitor is 0.01 to 10% based on the total weight of the dispersion.

10. The electrophoretic medium of claim 1 , wherein the weight percent of the inhibitor is 0.1 to 5% based on the total weight of the dispersion.

11. The electrophoretic medium of claim 1 further comprising a plurality of second charged particles and a plurality of third charged particles dispersed in the non-polar fluid, wherein each of the first, second, or third charged particles are a different color selected from red, green, blue, cyan, yellow, and magenta.

Assignees

• E Ink California Llc

Inventors

• Shao Lin
• Gu Haiyan
• Wang Ming
• Sofiyev Vladimir

Classifications

• C09D5/4411

  Homopolymers or copolymers of acrylates or methacrylates · CPC title

• G02F1/1681

  having two or more microcells partitioned by walls, e.g. of microcup type · CPC title

• C09D7/65

  macromolecular (C09D7/41-C09D7/48 take precedence) · CPC title

• C01G3/00

  Compounds of copper · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title