Encapsulant compositions, methods of manufacture and uses thereof
View Patent ↗An encapsulant composition containing about 15 to about 50 wt % of an ethylene/ethyl acrylate/maleic anhydride copolymer containing about 20 to about 40 wt % of an ethylene/glycidyl (meth)acrylate copolymer; about 2 to about 30 wt % of an ethylene/butyl acrylate/maleic anhydride copolymer; about 5 to about 50 wt % of polyethylene, about 0.05 to about 5 wt % of an adhesion promoter; and optionally about 0.01 to about 2 wt % of at least one additive. The composition is useful for encapsulating thin film devices. The disclosure also relates to a method of encapsulating thin film devices with the composition and to devices produced by the method.
1. An encapsulant composition comprising:
about 15 to about 50 wt % of an ethylene/ethyl acrylate/maleic anhydride copolymer;
about 20 to about 40 wt % of an ethylene/glycidyl (meth)acrylate copolymer; about 2 to about 30 wt % of an ethylene/butyl acrylate/maleic anhydride copolymer;
about 5 to about 50 wt % of polyethylene; and
about 0.05 to about 5 wt % of an adhesion promoter,
wherein the adhesion promoter is at least one selected from the group consisting of a silane adhesion promoter, an epoxy adhesion promoter, an acrylate adhesion promoter, and a blocked isocyanate adhesion promoter.
2. The encapsulant composition as claimed in claim 1 , wherein the ethylene/ethyl acrylate/maleic anhydride copolymer comprises about 10 to about 25 wt % ethyl acrylate units and about 1 to about 10 wt % maleic anhydride units, wherein the ethylene/glycidyl (meth)acrylate copolymer comprises about 5 to about 15 wt % glycidyl (meth)acrylate units and wherein the ethylene/butyl acrylate/maleic anhydride copolymer comprises about 3 to about 10 wt % buty acrylate units and from about 2 to about 10 wt % maleic anhydride units.
3. The encapsulant composition as claimed in claim 1 , wherein the copolymers are random copolymers and the polyethylene is a low density polyethylene, wherein the density of the low density polyethylene is about 0.9 to about 0.95 g/cm 3 .
4. The encapsulant composition as claimed in claim 1 , wherein the adhesion promoter comprises an organosilane wherein the organosilane contains an olefinic group having a terminal ethylenically unsaturated group or an epoxy group.
5. The encapsulant composition of claim 1 , further comprising about 0.01 to about 2 wt % of at least one additive.
6. A method of encapsulating a thin film device comprising: providing a thin film device;
placing the thin film device between a first substrate and a second substrate; and
sealing the first substrate and the second substrate together with the encapsulant composition as claimed in claim 1 to encapsulate the thin film device.
7. The method as claimed in claim 6 , wherein the thin film device is at least one selected from the group consisting of a photovoltaic cell, a light emitting diode, an organic light emitting diode and a liquid crystal display.
8. The method as claimed in claim 6 , wherein the first substrate and the second substrate are at least one selected from the group consisting of glass, plastic, and quartz crystal.
9. The method as claimed in claim 6 , wherein the first substrate and the second substrate are sealed together with the encapsulant composition by lamination.
10. The method as claimed in claim 9 comprising:
placing the encapsulant composition between the first substrate and second substrate to form a laminate;
applying pressure to the laminate;
heating the laminate to a temperature above the melting point of the encapsulant composition;
cooling the laminate to room temperature to form a seal between the first substrate and second substrate.
11. The method as claimed in claim 10 , wherein the space between the substrates not occupied by the thin film device is filled with nitrogen, argon or other inert gas or is evacuated to form a vacuum during the heating of the laminate.
12. An electronic device produced by the method as claimed in claim 6 .
13. The electronic device as claimed in claim 12 , wherein the thin film device is at least one selected from the group consisting of a photovoltaic cell, a light emitting diode, an organic light emitting diode and a liquid crystal display.
14. The encapsulant composition of claim 1 , wherein the adhesion promoter is a silane adhesion promoter and is at least one selected from the group consisting of 3-methacryloxypropyltrimethoxysilane 3-glycidoxypropyltrimethoxysilane, N-2-(benzylamino)-ethyl-3-aminopropyltrimethoxysilane, N-(f3-aminoethyl)-′yaminopropyltrimethoxysilane, and vinylbenzylaminoethylaminopropyltrimethoxysilane.
15. The encapsulant composition as claimed in claim 5 , wherein the at least one additive is selected from the group consisting of UV stabilizers, UV absorbers, antioxidants, lubricants, fillers, dyes and combinations thereof.