Functionalized quinacridone pigments

Patent metadata

Field	Value
Publication number	US-9752034-B2
Application number	US-201615347995-A
Country	US
Kind code	B2
Filing date	Nov 10, 2016
Priority date	Nov 11, 2015
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Quinacridone pigments that are surface-functionalized with glycidyl methacrylate, maleic anhydride, or 4-methacryloxyethyl trimellitic anhydride to create a functionalized pigment. The functional groups are then activated to bond hydrophobic polymers, thereby coating the pigment with the hydrophobic polymers. The quinacridone pigments can be used for a variety of applications. They are well-suited for use in electro-optic materials, such as electrophoretic media for use in electrophoretic displays.

First claim

The invention claimed is:

1. A pigment comprising Formula I:

wherein R 1 is a hydrogen, a C 1 -C 3 alkyl group, a halogen, a hydroxyl, or —CH 2 CHR 4 CH 2 OCOR 3 ;
R 2 is a hydrogen, C 1 -C 3 alkyl group, or a halogen;
R 3 is —C(CH 3 )CH 2 , or a hydrophobic polymer having a molecular weight between 5 kD and 100 kD; and
R 4 is —OH or —O[CH 2 CH(CH 2 OCOC(CH 3 )CH 2 )O] x H, and x is an integer from 1 to 15.

2. The pigment of claim 1 , wherein the hydrophobic polymer is a polymer comprising lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hexyl acrylate, hexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, n-octadecyl acrylate, n-octadecyl methacrylate, or a combination thereof.

3. The pigment of claim 1 , comprising Formula II:

4. The pigment of claim 1 , comprising Formula III

wherein m and n are independently integers between 10 and 200.

5. The pigment of claim 1 , comprising Formula IV

wherein m and n are independently integers between 10 and 200.

6. The pigment of claim 1 , wherein R 2 is —H or R 2 is —CH 3 .

7. An electrophoretic medium comprising a pigment of claim 1 .

8. An electro-optic display comprising a pigment of claim 1 .

9. A front plane laminate comprising a pigment of claim 1 .

10. A method for making a functionalized pigment, comprising:
providing a pigment comprising Formula V:

wherein R is a hydrogen, C 1 -C 3 alkyl group, or a halogen; and
reacting the pigment with glycidyl methacrylate, maleic anhydride, or 4-methacryloxyethyl trimellitic anhydride monomers to create a functionalized pigment.

11. The method of claim 10 , wherein the pigment is dispersed in toluene and reacted with methacrylate, maleic anhydride, or 4-methacryloxyethyl trimellitic anhydride at a temperature greater than 40° C.

12. The method of claim 10 , further comprising reacting the functionalized pigment with a hydrophobic polymer.

13. The method of claim 12 , wherein the functionalized pigment and the hydrophobic polymer are ball milled together prior to reacting.

14. The method of claim 12 , wherein the hydrophobic polymer is a polymer comprising lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hexyl acrylate, hexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, n-octadecyl acrylate, n-octadecyl methacrylate, or a combination thereof.

15. The method of claim 10 , wherein the pigment is a magenta pigment.

Assignees

• E Ink Corp

Inventors

• Wu Ziyan
• Feick Jason D

Classifications

• C09B48/00 Primary

  Quinacridones · CPC title

• C09D4/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16} · CPC title

• G02F2001/1678

  characterised by the composition or particle type · CPC title

• C07D471/04

  Ortho-condensed systems · CPC title

• C09D5/24

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title