Particles for electrophoretic displays

Patent metadata

Field	Value
Publication number	US-10344167-B2
Application number	US-201515536833-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Dec 19, 2014
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

This invention relates to polymer particles, a process for their preparation, the use of these particles for the preparation of an electrophoretic device, electrophoretic displays comprising such particle, and new polymerizable dyes.

First claim

The invention claimed is:

1. Coloured polymer particles for use in electrophoretic devices comprising monomer units of at least one polymerisable dye and at least one co-monomer, wherein the at least one polymerisable dye is selected of Formula (3):

wherein
R 1 and R 2 are independently of each other linear or branched, substituted or unsubstituted alkyl, where one or more non-adjacent carbon atoms may be replaced by O, S and/or N, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl;
R 3 and R 4 are independently of each other H or linear or branched, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, or R 3 and R 4 forming a cycloaliphatic ring;
L 1 and L 2 are independently of one another linear or branched, substituted or unsubstituted alkylene groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
Y 1 and Y 2 are independently of one another linear or branched alkyl groups or polymerisable groups;
and wherein at least one of Y 1 and Y 2 is a polymerisable group.

2. The coloured polymer particles according to claim 1 , wherein the at least one co-monomer comprises at least one amino group.

3. The coloured polymer particles according to claim 1 , wherein the at least one co-monomer is selected from the group consisting of 2-Aminoethyl methacrylate hydrochloride, 2-(tert-Butylamino)ethyl methacrylate, 2-(Diethylamino)ethyl methacrylate, 2-(Dimethylamino)ethyl methacrylate, [2-methacryloxyethyl] trimethyl ammonium chloride, [3-(Methacryloylamino)propyl]trimethylammonium chloride, and [2-(Methacryloyloxy)ethyl]trimethylammonium methyl sulfate.

4. The coloured polymer particles according to claim 1 , wherein said Y 1 and Y 2 are unsaturated alkyl groups comprising acrylate and methacrylate groups.

5. The coloured polymer particles according to claim 1 , wherein R 1 and R 2 are independently of each other aryl or C1-C15 alkyl.

6. The coloured polymer particles according to claim 1 , wherein R 3 and R 4 are independently of each other aryl or C1-C20 alkyl.

7. The coloured polymer particles according to claim 1 , wherein at least one black polymerisable dye is used.

8. The coloured polymer particles according to claim 1 , wherein the polymer particles have a diameter of 100-1000 nm.

9. A process for the preparation of the coloured polymer particles according to claim 1 comprising
a) polymerizing at least one polymerisable dye, at least one co-monomer, and at least one initiator, by dispersion polymerisation in at least one non-aqueous, non-polar solvent, and optionally
b) washing and drying the polymer particles wherein the at least one polymerisable dye of Formula (1) is used

wherein
A is a chromophoric residue comprising at least one polymerisable group;
R 1 and R 2 are independently of each other linear or branched, substituted or unsubstituted alkyl, where one or more non-adjacent carbon atoms may be replaced by O, S and/or N, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl;
R 3 and R 4 are independently of each other H or linear or branched, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, or R 3 and R 4 forming a cycloaliphatic ring.

10. An electrophoretic fluid comprising polymer particles prepared by the process according to claim 9 .

11. A device comprising the polymer particles according to claim 1 , wherein the device is an optical, electrooptical, electronic, electrochemical, electrophotographic, electrowetting and electrophoretic displays, and in security, cosmetic, decorative, and diagnostic applications.

12. The device as claimed in claim 11 , wherein the device is in mono, bi or polychromal electrophoretic device.

13. An electrophoretic fluid comprising the polymer particles according to claim 1 .

14. An electrophoretic display device comprising an electrophoretic fluid according to claim 13 .

15. The electrophoretic display device according to claim 14 , wherein the electrophoretic fluid is applied by a technique selected from the group consisting of inkjet printing, slot die spraying, nozzle spraying, and flexographic printing.

16. The coloured polymer particles according to claim 1 , wherein the polymerisable dyes comprise two polymerisable groups selected from the group consisting of methacrylates, acrylates, methacrylamides, acrylamides, acrylonitriles, α-substituted acrylates, styrenes and vinyl ethers, vinyl esthers, propenyl ethers, oxetanes and epoxys.

17. The coloured polymer particles according to claim 1 , wherein the polymerisable dyes comprise two polymerisable groups selected from the group consisting of methacrylates and acrylates.

18. The coloured polymer particles according to claim 1 , wherein the polymerisable dyes are selected from the group consisting of

19. The coloured polymer particles according to claim 1 , wherein
R 1 and R 2 are independently of each other aryl or C2-C12 alkyl and
R 3 and R 4 are independently of each other aryl or C1-C15 alkyl.

20. The coloured polymer particles according to claim 1 , which comprises
0.1-15% by weight of the at least one polymerisable dye according to formula (3),
50-95%, by weight of the at least co-monomer and
1-40%, by weight of the at least one co-monomer comprising amino groups all percentages are based on the total weight of the polymerizable.

21. The coloured polymer particles according to claim 1 , which comprises
1-10% by weight of the at least one polymerizable dye according to formula (3),
70-90% by weight of the at least one co-monomer,
1-10% by weight of the at least one co-monomer comprising amino groups, and
0.1-5% by weight of initiator, all percentages are based on the total weight of the polymerizable composition.

Assignees

• Merck Patent Gmbh
• Univ Belfast

Inventors

• Wilson Jonathan Henry
• Farrand Louise Diane
• Lawrence Anthony
• Youngs Sarah

Classifications

• C09B35/037

  characterised by two coupling components of different types · CPC title

• C09B35/06

  the tetrazo component being a naphthalene derivative · CPC title

• C09B31/14

  Heterocyclic components · CPC title

• G02F2001/1678

  characterised by the composition or particle type · CPC title

• C08F2/06

  Organic solvent · CPC title