Black polymer particles

Patent metadata

Field	Value
Publication number	US-2016297945-A1
Application number	US-201415100390-A
Country	US
Kind code	A1
Filing date	Nov 18, 2014
Priority date	Dec 2, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

This invention relates to a process for the preparation of a dispersion comprising black polymer particles, such black polymer particles prepared by the process, the use of the dispersion and the black polymer particles in electrophoretic fluids, and electrophoretic display devices comprising such fluids.

First claim

1 . A process for the preparation of black polymer particles dispersed in at least one non-polar fluorinated solvent for use in electrophoretic devices, the process comprising the steps of
a) forming a reverse emulsion comprising at least one polymer, at least one carbon black pigment, at least one polar solvent, at least one non-polar, fluorinated solvent, and at least one surfactant, and b) removing the polar solvent or polar solvents by evaporative methods, wherein the non-polar, fluorinated solvent or solvents are not removed.

2 . Process according to claim 1 , wherein the reverse emulsion of step a) is prepared by a process comprising; a1) forming a polar phase by mixing at least one polymer, at least one carbon black pigment, and at least one polar solvent, a2) forming a non-polar phase by mixing at least one non-polar, fluorinated solvent, and at least one surfactant, a 3 ) combining the polar phase and the non-polar phase, and a4) homogenizing the combined phases to form the reverse emulsion.

3 . Process according to claim 1 , wherein the polymer of step a) is produced from at least one monomer that is insoluble in the non-polar, fluorinated solvent, or that the monomer is soluble in the non-polar fluorinated solvent, but the polymer is insoluble in the non-polar fluorinated solvent.

4 . Process according to claim 1 , wherein the polymer of step a) is selected from poly(vinyl pyrrolidone), poly(acrylanaide), poly(acrylic acid) and poly(methacrylic acid).

5 . Process according to claim 1 , wherein the non-polar fluorinated solvent used in step a) is a perfluorinated hydrocarbon having a refractive index of ≦1.3, a dielectric constant≦10, a viscosity≦5 cst, and a boiling point≧80° C., and has a refractive index and a density similar to that of the polymer used in step a).

6 . Process according to claim 1 , wherein the polar solvent used in step a) is selected from water, low molecular weight alcohols, methyl ethyl ketone, acetonitrile, DMSO, DMF or mixtures thereof.

7 . Process according to claim 1 , wherein the reverse emulsion comprises perfluoro(tributylamine) as non-polar phase, and a polar phaac that comprises one or more of water, ethanol, methanol, methyl ethyl ketone, or industrial methylated spirits.

8 . Process according to claim 1 , further comprising adding a blue or black dye is in step a).

9 . Process according to claim 1 , further comprising step c) concentrating the non-polar fluorinated solvent or solvents.

10 . Process according to claim 1 , further comprising step c′) removing the non-polar fluorinated solvent or solvents.

11 . A dispersion prepared by a process according to claim 1 .

12 .- 20 . (canceled)

21 . A dispersion comprising black particles prepared according to claim 10 .

22 . A dispersion comprising a non-polar, fluorinated solvent, and black particles, and optionally a dye that is soluble in the non-polar, fluorinated solvent, wherein the black particles comprise carbon black, a polymer, a fluorinated surfactant, and optionally a blue and/or black dye.

23 . Dispersion according to claim 22 , comprising perfluoro(tributylamine), and the black particles consist of the carbon black, poly(vinyl pyrrolidone) and/or poly(acrylic acid), and a poly(hexafluoropropylene oxide) polymeric surfactant with a monofunctional carboxylic acid end group, and a weight-average molecular weight Mw between 5000 and 8000.

24 . An electronic device comprising a dispersion of claim 22 , wherein the electronic device is selected from the group consisting of an electrooptical device, electrochemical device, electrophotographic device, electrowetting device, electro-osmotic device, electrohydrodynamic device, and electrophoretic device.

25 . A mono, bi or polychromal electrophoretic device comprising the dispersion according to claim 21 .

26 . A Total Internal Reflection (TIR) type device comprising the dispersion according to claim 21 .

27 . An electrophoretic display device comprising the dispersion according to claim 21 .

28 . The device according to claim 24 , the device selected from the group consisting of a dynamic keypad, e-paper watch, dynamic pricing and advertising device, e-reader, rollable display, smart card media, product packaging, mobile phone, lab top, display card, digital signage and shelf edge label.

29 . The device according to claim 24 , wherein the dispersion is applied to the device by a technique selected from inkjet printing, slot die spraying, nozzle spraying, and flexographic printing.

Assignees

• Merck Patent Gmbh
• The Queen'S Univ Of Belfast

Inventors

• Farrand Louise D
• Norman Sarah

Classifications

• C09B67/0097

  Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes · CPC title

• C09B67/009

  polymeric dispersing agent · CPC title

• C08L39/06

  Homopolymers or copolymers of N-vinyl-pyrrolidones · CPC title

• C09D5/4411

  Homopolymers or copolymers of acrylates or methacrylates · CPC title

• C08J2339/06

  Homopolymers or copolymers of N-vinyl-pyrrolidones · CPC title