Electro-optic display and materials for use therein

• US 7,535,624 B2
• Filed: 07/05/2006
• Issued: 05/19/2009
• Est. Priority Date: 07/09/2001
• Status: Expired due to Term

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Abramson, Justin J., Geramita, Katherine, Webber, Richard M., Ritter, John E., Crossley, Glen, Zehner, Robert W., Steiner, Michael L., Duthaler, Gregg M., Loxley, Andrew L., Amundson, Karl R., Zhang, Libing, Holman, Mavyn M.
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): PINKNEY, DAWAYNE
• Application Number:
  US11/428,584
• Publication Number:
  US 20070035808A1
• Time in Patent Office: 1,049 Days
• Field of Search: 359/259, 359/296, 345 84- 85, 345/107, 430 31- 38, 347111-112, 399/131, 204/600
• US Class Current: 359/296
• CPC Class Codes: C08K 3/017 Antistatic agents
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C09J 11/04 inorganic
• CPC Class Codes: C09J 2301/408 additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• CPC Class Codes: C09J 9/02 Electrically-conducting adhesives
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133368 Cells having two substrates with different characteristics, e.g. different thickness or material
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules
• CPC Class Codes: G02F 1/172 based on a suspension of orientable dipolar particles, e.g. suspended particles displays
• CPC Class Codes: G02F 2202/16 conductive
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: H05K 3/323 by applying an anisotropic conductive adhesive layer over an array of pads

Abstract

An electro-optic display comprises a layer (130) of a solid electro-optic material, at least one electrode disposed adjacent the layer (130) of electro-optic material, and a layer (180) of a lamination adhesive interposed between the layer (130) of electro-optic material and the electrode, the lamination adhesive (180) having a higher electrical conductivity in a direction perpendicular to the layer of lamination adhesive than in the plane of the layer.

Claims

1. An electro-optic display comprising a layer of a solid electro-optic material, and at least one electrode arranged to apply an electric field to the layer of electro-optic material, the layer of electro-optic material comprising a binder, the binder having a volume resistivity, measured at 10°

C., which does not change by a factor of more than about 3 after being held at 25°

C. and 45 per cent relative humidity for 1000 hours.

2. An electro-optic display according to claim 1 wherein the volume resistivity of the binder measured at 10°

C. does not change by a factor of more than about 2 after being held at 25°

C. and 45 per cent relative humidity for 1000 hours.

3. An electro-optic display according to claim 2 wherein the volume resistivity of the binder measured at 10°

C. does not change by a factor of more than about 1.5 after being held at 25°

C. and 45 per cent relative humidity for 1000 hours.

4. An electro-optic display according to claim 1 wherein the binder essentially free from plasticizer.

5. An electro-optic display according to claim 1 wherein the binder exhibits a change in the enthalpy associated with any phase transition in the material, as measured by differential scanning calorimetry, that is not more than about 2 Joules per gram after being held at 25°

C. and 45 per cent relative humidity for 1000 hours.

6. An electro-optic display according to claim 1 wherein the binder exhibits a change in dielectric constant of less than about 2 after being held at 25°

C. and 45 percent relative humidity for 1000 hours.

7. An electro-optic display according to claim 1 wherein the binder comprises a blend of at least two binder materials, at least one of which has a volume resistivity, measured at 10°

C., which changes by a factor of more than 3 after being held at 25°

C. and 45 percent relative humidity for 1000 hours.

8. An electro-optic display according to claim 1 wherein the binder comprises at least one polyurethane.

9. An electro-optic display according to claim 8 wherein the binder comprises a blend of at least two polyurethanes.

10. An electro-optic display according to claim 9 wherein the binder comprises a blend of a non-ionically stabilized polyester-based polyurethane and an anionically stabilized polyester-based polyurethane.

11. An electro-optic display according to claim 1 wherein the binder has a volume resistivity, measured at 10°

C., of not more than about 3×

10¹⁰ ohm cm.

12. An electro-optic display according to claim 1 wherein the electro-optic medium comprises a rotating bichromal member, polymer-dispersed electrophoretic or microcell electrophoretic medium.

13. An electro-optic display according to claim 1 wherein the electro-optic medium comprises an electrophoretic medium comprising a plurality of capsules, each capsule comprising a capsule wall and an internal phase encapsulated within capsule wall, the internal phase comprising electrically charged particles suspended in a fluid and capable of moving through the fluid on application of an electric field to the electrophoretic material.