Electro-optic displays, and materials for use therein
A flexible electro-optic display comprises a layer of solid electro-optic material; a backplane comprising at least one electrode arranged to apply an electric field to the layer of electro-optic material; and an adhesive layer disposed between the layer of electro-optic material and the backplane and adhesively securing the layer of electro-optic material to the backplane, the adhesive layer having a storage modulus (G′) of at least about 10 4 Pascals at 10 −3 Hz and 70° C.
1. A flexible electro-optic display comprising:
a layer of solid electro-optic material capable of changing at least one optical characteristic upon application of an electric field thereto;
a backplane comprising at least one electrode arranged to apply an electric field to the layer of electro-optic material; and
an adhesive layer disposed between the layer of electro-optic material and the backplane and adhesively securing the layer of electro-optic material to the backplane,
the adhesive layer having a storage modulus (G′) of at least about 10 4 Pascals at 10 −3 Hz and 70° C.
2. An electro-optic display according to claim 1 wherein the backplane comprises a polymeric film having a thickness not greater than about 300 μm, the display further comprising a front plane lying on the opposed side of the electro-optic material from the backplane and comprising a polymeric film having a thickness not greater than about 300 μm.
3. A display according to claim 2 wherein the backplane and front plane each comprise a polymeric film having a thickness not greater than about 100 μm.
4. A display according to claim 1 wherein the backplane comprises a plurality of non-linear electronic devices comprising conductive polymers.
5. A display according to claim 1 wherein the adhesive layer has a storage modulus (G′) of at least about 3×10 4 Pascals at 10 −3 Hz and 70° C.
6. A display according to claim 5 wherein the adhesive layer has a storage modulus (G′) of at least about 6×10 4 Pascals at 10 −3 Hz and 70° C.
7. A display according to claim 1 having a second layer of adhesive material disposed on the opposed side of the electro-optic material from the backplane, the second layer of adhesive having a storage modulus (G′) of at least about 10 4 Pascals at 10 −3 Hz and 70° C.
8. A display according to claim 1 wherein the adhesive layer comprises a polyurethane.
9. A display according to claim 1 wherein the adhesive layer comprises a cross-linked polymer.
10. A display according to claim 1 wherein the adhesive layer has been cross-linked with a thermally-activated cross-linking agent.
11. A display according to claim 10 wherein the adhesive layer has been cross-linked with a thermally-activated cross-linking agent containing an epoxy group.
12. A display according to claim 10 wherein the adhesive layer has been cross-linked with N,N-diglycidylaniline.
13. A display according to claim 9 wherein the adhesive layer has been cross-linked with an ultra-violet activated cross-linking agent.
14. A process for producing a flexible electro-optic display, the process comprising:
providing an assembly comprising a layer of solid electro-optic material capable of changing at least one optical characteristic upon application of an electric field thereto; a flexible backplane comprising at least one electrode arranged to apply an electric field to the layer of electro-optic material; and an adhesive layer disposed between the layer of electro-optic material and the backplane and adhesively securing the layer of electro-optic material to the backplane, the adhesive layer comprising a cross-linking agent capable of cross-linking the adhesive layer, and
exposing the adhesive layer to conditions effective to activate the cross-linking agent, thereby cross-linking the adhesive layer to produce an adhesive layer having a storage modulus (G′) of at least about 10 4 Pascals at 10 −3 Hz and 70° C.
15. A process according to claim 14 wherein the adhesive layer produced by cross-linking has a storage modulus (G′) of at least about 3×10 4 Pascals at 10 −3 Hz and 70° C.
16. A process according to claim 15 wherein the adhesive layer produced by cross-linking has a storage modulus (G′) of at least about 6×10 4 Pascals at 10 −3 Hz and 70° C.
17. A process according to claim 14 wherein the adhesive layer comprises a polyurethane.
18. A process according to claim 14 wherein the adhesive layer is cross-linked with a thermally-activated cross-linking agent.
19. A process according to claim 18 wherein the adhesive layer is cross-linked with a thermally-activated cross-linking agent containing an epoxy group.
20. A process according to claim 19 wherein the adhesive layer is cross-linked with N,N-diglycidylaniline.