Adhesive encapsulating composition and electronic devices made therewith
Adhesive encapsulating compositions for use in electronic devices such as organic electroluminescent devices, touch screens, photovoltaic devices, and thin film transistors are disclosed herein. The adhesive encapsulating compositions include pressure sensitive adhesives comprising one or more polyisobutylene resins, in combination with optional multifunctional (meth)acrylate monomers and/or optional tackifiers.
1. An adhesive encapsulating composition for use in an electronic device, comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a multifunctional (meth)acrylate monomer;
wherein the adhesive encapsulating composition is substantially free of tackifier.
2. The adhesive encapsulating composition of claim 1 , wherein the first isobutylene resin has a weight average molecular weight of greater than about 1,000,000 g/mol.
3. The adhesive encapsulating composition of claim 1 , wherein the first polyisobutylene comprises at least about 50 wt. % of the total weight of the adhesive encapsulating composition.
4. An adhesive encapsulating composition for use in an electronic device, comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a second polyisobutylene resin having a weight average molecular weight of less than about 100,000 g/mol,
wherein the adhesive encapsulating composition is substantially free of tackifier.
5. The adhesive encapsulating composition of claim 4 , wherein the first isobutylene resin has a weight average molecular weight of greater than about 400,000 g/mol.
6. The adhesive encapsulating composition of claim 4 , wherein the first polyisobutylene comprises at least about 50 wt. % of the total weight of the adhesive encapsulating composition.
7. The adhesive encapsulating composition of claim 4 , further comprising a multifunctional (meth)acrylate monomer.
8. The adhesive encapsulating composition of claim 7 , comprising:
from about 50 to about 80 wt. % of the first polyisobutylene resin;
from about 10 to about 30 wt. % of the second polyisobutylene resin; and
from about 10 to about 20 wt. % of the multifunctional (meth)acrylate monomer;
all relative to the total weight of the adhesive encapsulating composition.
9. An adhesive encapsulating composition for use in an electronic device, comprising:
a second polyisobutylene resin having a weight average molecular weight of less than about 300,000 g/mol;
a multifunctional (meth)acrylate monomer; and
a tackifier,
wherein the adhesive encapsulating composition is free of a first polyisobutylene having a weight average molecular weight of greater than about 300,000 g/mol.
10. The adhesive encapsulating composition of claim 9 , wherein the second isobutylene resin has a weight average molecular weight of less than about 100,000 g/mol.
11. The adhesive encapsulating composition of claim 9 , comprising:
from about 10 to about 50 wt. % of the second polyisobutylene resin;
from about 10 to about 40 wt. % of the multifunctional (meth)acrylate monomer;
from about 30 to about 60 wt. % of the tackifier;
all relative to the total weight of the adhesive encapsulating composition.
12. An adhesive encapsulating composition for use in an electronic device, comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol, wherein the first polyisobutylene resin comprises 20 wt. % or less of the total weight of the adhesive encapsulating composition;
a second polyisobutylene resin having a weight average molecular weight of less than about 300,000 g/mol;
a multifunctional (meth)acrylate monomer; and
a tackifier.
13. The adhesive encapsulating composition of claim 12 , wherein the first isobutylene resin has a weight average molecular weight of greater than about 1,000,000 g/mol.
14. The adhesive encapsulating composition of claim 12 , comprising:
from about 10 to about 30 wt. % of the second polyisobutylene resin;
from about 10 to about 30 wt. % of the multifunctional (meth)acrylate monomer;
from about 40 to about 60 wt. % of the tackifier;
all relative to the total weight of the adhesive encapsulating composition.
15. The adhesive encapsulating composition of claim 1 , wherein the multifunctional (meth)acrylate monomer comprises an aliphatic di(meth)acrylate.
16. The adhesive encapsulating composition of claim 1 , wherein the multifunctional (meth)acrylate monomer comprises a multifunctional (meth)acrylate/epoxy monomer.
17. The adhesive encapsulating composition of claim 1 , wherein the adhesive encapsulating composition is photopolymerizable and comprises a photoinitiator.
18. The adhesive encapsulating composition of claim 1 , wherein the adhesive encapsulating composition is thermally polymerizable and comprises a thermal initiator.
19. The adhesive encapsulating composition of claim 1 , further comprising particles.
20. An adhesive encapsulating film comprising an adhesive layer disposed on a substrate, the adhesive layer comprising the adhesive encapsulating composition of claim 1 .
21. An adhesive encapsulating film comprising an adhesive layer disposed on a substrate, and a gas-barrier film disposed on the adhesive layer opposite the substrate, the adhesive layer comprising the adhesive encapsulating composition of claim 1 .
22. An adhesive encapsulating film comprising an adhesive layer disposed on a substrate, and a trapping layer disposed either on the adhesive layer opposite the substrate or between the adhesive layer and the substrate, the adhesive layer comprising the adhesive encapsulating composition of claim 1 .
23. An organic electroluminescent device comprising:
a pair of opposing electrodes;
a light-emitting unit having at least an organic light-emitting layer, the light-emitting unit disposed between the pair of opposing electrodes; and
an adhesive encapsulating composition disposed on, above, or around the light-emitting unit, the adhesive encapsulating composition comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a multifunctional (meth)acrylate monomer;
wherein the adhesive encapsulating composition is substantially free of tackifier.
24. The organic electroluminescent device of claim 23 , wherein the device is flexible.
25. A touch screen comprising:
a glass or polymeric substrate;
a substantially transparent conductive metal disposed on the substrate; and
an adhesive encapsulating composition disposed on, above, or around the metal, the adhesive encapsulating composition comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a multifunctional (meth)acrylate monomer;
wherein the adhesive encapsulating composition is substantially free of tackifier.
26. A photovoltaic device comprising:
a photovoltaic cell or an array of photovoltaic cells; and
an adhesive encapsulating composition disposed on, above, or around the photovoltaic cell or any one of the photovoltaic cells of the array of photovoltaic cells, the adhesive encapsulating composition comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a multifunctional (meth)acrylate monomer;
wherein the adhesive encapsulating composition is substantially free of tackifier.
27. A thin film transistor comprising:
a semiconductor layer; and
an adhesive encapsulating composition disposed on, above, or around the semiconductor layer, the adhesive encapsulating composition comprising:
a first polyisobutylene resin having a weight average molecular weight of greater than about 300,000 g/mol; and
a multifunctional (meth)acrylate monomer;
wherein the adhesive encapsulating composition is substantially free of tackifier.