Functionalized quinacridone pigments

• US 9,752,034 B2
• Filed: 11/10/2016
• Issued: 09/05/2017
• Est. Priority Date: 11/11/2015
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Wu, Ziyan, Feick, Jason D.
• Primary Examiner(s): CHEUNG, WILLIAM K
• Application Number:
  US15/347,995
• Publication Number:
  US 20170130053A1
• Time in Patent Office: 299 Days
• Field of Search: 526204, 8454, 8461
• CPC Class Codes: C07D 471/04 Ortho-condensed systems
• CPC Class Codes: C08F 120/18 with acrylic or methacrylic acids
• CPC Class Codes: C09B 48/00 Quinacridones
• CPC Class Codes: C09B 69/109 containing other specific dyes
• CPC Class Codes: C09D 11/033 characterised by the solvent
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/107 from unsaturated acids or derivatives thereof
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: C09D 4/00 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 Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 5/4411 Homopolymers or copolymers of acrylates or methacrylates
• CPC Class Codes: G02F 2001/1678 characterised by the composition or particle type

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.

Claims

1. A pigment comprising Formula I:

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

5. The pigment of claim 1, comprising Formula IV

6. The pigment of claim 1, wherein R₂ is —

H or R₂ is —

CH₃.

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;

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.