Particles for electrophoretic displays

Patent metadata

Field	Value
Publication number	US-9588357-B2
Application number	US-201314400623-A
Country	US
Kind code	B2
Filing date	May 7, 2013
Priority date	May 14, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

This invention relates to particles comprising a pigment core particle encapsulated by a polymer, a process for their preparation, electrophoretic fluids comprising such particles, and electrophoretic display devices comprising such fluids.

First claim

The invention claimed is:

1. Particles comprising a single organic or inorganic pigment core particle encapsulated by a polymer having monomer units of at least one polymerisable steric stabiliser, at least one co-monomer, optionally at least one charged co-monomer, and optionally at least one crosslinking co-monomer, and the particles comprise at least one surfactant, wherein the amount of surfactant is from 1-10% by weight based on the weight of the pigment.

2. The particles according to claim 1 , wherein a single organic or inorganic pigment core particle is coated with at least one surfactant and encapsulated by a polymer.

3. The particles according to claim 1 , wherein the pigment core particle is titanium dioxide in the rutile, anatase, or amorphous modification or carbon black.

4. The particles according to claim 1 , wherein the surfactant is soluble in non-polar organic solvents.

5. The particles according to claim 1 , wherein the polymerisable steric stabiliser is a poly(dimethylsiloxane) macromonomer with at least one polymerisable group and a molecular weight in the range of 1000-50000.

6. The particles according to claim 1 , wherein the polymerisable steric stabiliser is a mono-methacrylate terminated poly-dimethylsiloxane.

7. The particles according to claim 1 , wherein the percentage of polymerisable steric stabiliser is at least 5% by weight based on the weight of the particle.

8. The particles according to claim 1 , wherein the particles have a diameter of 400-1000 nm.

9. An optical, electrooptical, electronic, electrochemical, electrophotographic, electrowetting, electrophoretic display or device comprising the particles according to claim 1 .

10. An electrophoretic fluid comprising particles according to claim 1 .

11. An electrophoretic display device comprising an electrophoretic fluid according to claim 10 .

12. An electrophoretic display device according to claim 11 , wherein the electrophoretic fluid is applied by a technique selected from inkjet printing, slot die spraying, nozzle spraying, and flexographic printing, or any other contact or contactless printing or deposition technique.

Assignees

• Merck Patent Gmbh

Inventors

• Blackman Lewis
• Farrand Louise Diane
• Wilson Jonathan Henry
• Biggs Simon
• Cayre Olivier
• Lawson Simon
• Richez Alexandre

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C08F220/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• C01P2006/40

  Electric properties · CPC title

• C09C1/3684

  Treatment with organo-silicon compounds · CPC title

• C09C1/3669

  Treatment with low-molecular organic compounds · CPC title