Dual curing optically transparent adhesive compositions

1. An adhesive composition comprising:

a photo- and/or heat-curable polyolefin-based oligomer;

a moisture-curable polyolefin-based oligomer;

a curative package to trigger and/or accelerate cure of the oligomer(s) under appropriate cure conditions; and

at least one polyolefin-based polyurethane that is not reactive under the cure conditions with the photo- and/or heat-curable polyolefin-based oligomer or the moisture-curable polyolefin-based oligomer, represented by the formula:

HO—U—P—U—OH

where U comprises a urethane or urea linkage, and P comprises a polyolefin backbone.

2. The adhesive composition of claim 1 , wherein the curative package comprises one or more curatives and/or one or more catalysts appropriate to trigger and/or accelerate cure of the oligomer(s).

3. The adhesive composition of claim 1 , wherein the curative package comprises a photoinitiator.

4. The adhesive composition of claim 1 , wherein the curative package comprises a thermal initiator.

5. The adhesive composition of claim 1 , wherein the curative package comprises a moisture cure catalyst.

6. The composition of claim 5 , wherein moisture cure catalyst is present in amounts of about 0.01 percent by weight to about 1.0 percent by weight of the total composition.

7. The composition of claim 3 , wherein the photo-initiator is present in amounts of about 0.1 percent by weight to about 3.0 percent by weight of the total composition.

8. The composition of claim 4 , wherein the thermal initiator is present in amounts of about 0.1 percent by weight to about 3.0 percent by weight of the total composition.

9. The composition of claim 1 , having a haze value of 0-2 and a yellowness value of 0-2, after cure.

10. The composition of claim 1 , wherein the photo- and/or heat-curable polyolefin-based oligomer(s) has a backbone selected from the group consisting of polybutadiene, hydrogenated polybutadiene, butyl rubber, polyisobutylene and combinations thereof.

11. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer contains terminal and/or pendent alkoxy groups.

12. The composition of claim 1 , wherein the photo- or heat-curable polyolefin-based oligomer contains terminal and/or pendent (meth)acrylate groups and/or vinyl groups.

13. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer is present in amounts of about 5 percent by weight to about 80 percent by weight of the total composition.

14. The composition of claim 1 , wherein the photo- or heat-curable polyolefin-based oligomer is present in amounts of about 5 percent by weight to about 80 percent by weight of the total composition.

15. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer has the structure:

M—(U—P) n —U—M

wherein M represents one or more moisture-curable groups, U represents a component which includes a urethane or urea linkage, and P represents a polyolefin backbone, and n is 1 to 100.

16. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer has the structure:

17. The composition of claim 1 , wherein the heat-curable polyolefin-based oligomer has the structure:

H—(U—P) n —U—H

wherein H represents one or more (meth)acrylate or vinyl groups, U represents a component which includes a urethane or urea linkage, and P represents a polyole fin backbone, and n is 1 to 100.

18. The composition of claim 1 , wherein the photo-curable polyolefin-based oligomer has the structure:

Ph-(U—P) n —U-Ph

wherein Ph represents one or more photo-curable groups, U represents a component which includes a urethane or urea linkage, and P represents a polyolefin backbone, and n is 1 to 100.

19. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer is a polyurethane reaction product of a polyolefin diol and an isocyanato alkoxysilane.

20. The composition of claim 1 , wherein the moisture-curable polyolefin-based oligomer is a polyurethane reaction product of a polybutadiene diol and isocyanato trimethoxysilane.

21. The composition of claim 1 , wherein each of the polyolefin-based oligomers is based on butyl rubber or polyisobutylene and has an average molecular weight (Mw) of about 10,000 to about 15,000.

22. The composition of claim 1 , further comprising a (meth)acrylate monomer.

23. The composition of claim 1 , further comprising a component selected from the group consisting of diluents, thickeners, stabilizers, colorants, pigments, antioxidants, plasticizers, rheology modifiers and combinations thereof.

24. A process for making an optical assembly comprising the steps of:

a) providing a display panel and a top substrate comprising a cover lens or a touch panel;

b) providing the adhesive composition according to claim 1 so that it is disposed between the top substrate and the display panel; and

c) curing the adhesive composition by exposure to at least one of radiation in the electromagnetic spectrum, heat and moisture.

25. A process for reworking the optical assembly of claim 24 , comprising the steps of:

e) detaching a top substrate from a display panel by heating the optical assembly;

f) allowing the detached substrate and display panel to cool to room temperature (25° C.); and

f) peeling the adhesive from the top substrate and/or display panel.

26. An optical assembly comprising a display panel, a top substrate for the display panel and a reaction product of the adhesive composition of claim 1 disposed therebetween.