Transformable pressure sensitive adhesive tape and use thereof in display screens

• US 20060100299A1
• Filed: 07/18/2003
• Published: 05/11/2006
• Est. Priority Date: 07/24/2002
• Status: Abandoned Application

• Current Assignee: Adhesives Research Inc.
• Original Assignee: Adhesives Research Inc.
• Inventors: Malik, Ranjit, Williams, David H III, Harkins, Brian A
• Application Number:
  US10/522,149
• Publication Number:
  US 20060100299A1
• Time in Patent Office: Days
• US Class Current: 522/31
• CPC Class Codes: C08G 59/18 Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
• CPC Class Codes: C09J 163/00 Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: H01J 2211/48 Sealing, e.g. seals specially adapted for leading-in conductors
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 59/8722 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/874 including getter material or desiccant

Abstract

A transformable pressure sensitive adhesive composition comprised of from about 15 to about 80% by weight of a polymer having a softening point greater than 60° C.; from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30° C.; a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin; and optionally, a crosslinking agent. The transformable pressure sensitive adhesive has particular applicability in connection with organic light emitting diode display devices, light emitting diode display devices, medical diagnostic testing devices, flexible or rigid LCD display devices, plasma display devices, and electrochromic devices.

Claims

1. A transformable pressure sensitive adhesive composition comprised of:

(a) from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin; and

(d) optionally, a crosslinking agent.

2. The composition of claim 1, wherein said polymer is selected from the group consisting of polyurethane, poly(isobutylene), poly(arylonitrile butadiene), polyvinylidene chloride, aromatic liquid crystalline polymers, copolymers of ethylene norbornene, poly(meth)acrylate, polycarbonate, polyester, polycaprolactone, polysulfone, polyphenylene oxide resins, phenolic resins, and phenoxy resins.

3. The composition of claim 1, wherein said resin is an epoxy resin.

4. The composition of claim 3, wherein said epoxy resin is a glycidyl ether of alcohol and phenol.

5. The composition of claim 1 wherein the latent initiator is a free radical and/or onium salt cationic photoinitiator.

6. The composition of claim 1 further comprising nanoclays in an amount of from 1 to 20% by weight.

7. The composition of claim 1 further comprising a desiccant material.

8. The composition of claim 1 further comprising at least one material selected from the group consisting of tackifying resins, plasticizers, fillers or reinforcing polymers.

9. The composition of claim 1, further including a crosslinking agent.

10. The composition of claim 9, wherein said crosslinking agent is selected from the group consisting of isocyanates, aziridines, and organometallic compounds.

11. The composition of claim 1, wherein said polymer is an acrylate.

12. In an organic light emitting diode display device, comprised of a substrate, two electrodes, organic stack between said electrodes, and a cover for said device, the improvement wherein said electrodes and organic stack are encapsulated in a transformed pressure sensitive adhesive which serves as a barrier layer for moisture and other contaminants, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of from (a) about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin; and

(d) optionally a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator.

18. The device of any one of claims 12-17 wherein said adhesive has been transformed by application of a suitable trigger to activate said latent initiator.

19. The device of any one of claims 12-17 wherein said adhesive includes a desiccant material.

20. The device of any one of claims 12-17 further including a crosslinking agent.

21. The device of claim 20, wherein said crosslinking agent is selected from the group consisting of isocyanates, aziridines, and organometallic compounds.

22. The device of any one of claims 12-17 wherein said polymer is an acrylate.

23. The device of any one of claims 12-17 wherein said polymer is selected from the group consisting of polyurethane, poly(isobutylene), poly(acrylonitrile butadiene), polyvinylidene chloride, aromatic liquid crystalline polymers, copolymers of ethylene norbornene, poly(meth)acrylate, polycarbonate, polyester, polycaprolactone, polysulfone, polyphenylene oxide resins, phenolic resins, and phenoxy resins.

24. The device of any one of claims 12-17, wherein said polymerizable resin is an epoxy resin.

25. The device of claim 24, wherein said epoxy resin is a glycidyl ether of alcohol and phenol.

26. The device of any one of claims 12-17 wherein the latent initiator is a free radical and/or onium salt cationic photoinitiator.

27. The device of any one of claims 12-17 further comprising nanoclays in an amount of from 1 to 20% by weight.

28. The device of any one of claims 12-17 further comprising at least one material selected from the group consisting of tackifying resins, plasticizers, fillers or reinforcing polymers.

13. In a light emitting diode display device, the improvement wherein the perimeter seal of said device is comprised of a transformed pressure sensitive adhesive which serves as a barrier layer for moisture and other contaminants, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin, and (d) optionally, a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator.

14. In a medical diagnostic testing device, comprised of a plastic housing and a diagnostic test strip in the housing, the improvement wherein said device includes a transformed pressure sensitive adhesive, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of (a) from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin, and (d) optionally a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator

15. In a flexible or rigid LCD display device, the improvement wherein the perimeter seal of said device includes a transformed pressure sensitive adhesive, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of (a) from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin, and (d) optionally a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator.

16. In a plasma display device, the improvement wherein the perimeter seal of said device includes a transformed pressure sensitive adhesive, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of (a) from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.; and

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin, and (d) optionally a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator.

17. In an electrochromic device, the improvement wherein the perimeter seal of said device includes a transformed pressure sensitive adhesive, said transformed pressure sensitive adhesive being applied in the form of a pressure sensitive adhesive comprised of (a) from about 15 to about 80% by weight of a polymer having a softening point greater than 60°

C.;

(b) from about 20 to about 85% by weight of a polymerizable resin having a softening point less than 30°

C.;

(c) a latent initiator in an amount sufficient to cause a reaction between said polymer and said resin, and (d) optionally a crosslinking agent, with said adhesive subsequently being transformed upon application of a suitable trigger to transform said adhesive by activation of said latent initiator.