Encapsulant materials and associated devices
View Patent ↗Compositions suitable for use as encapsulants are described. The inventive compositions include a high molecular weight polymeric material, a curing agent, an inorganic compound, and a coupling agent. Optional elements include adhesion promoting agents, colorants, antioxidants, and UV absorbers. The compositions have desirable diffusivity properties, making them suitable for use in devices in which a substantial blocking of moisture ingress is desired, such as photovoltaic (PV) modules.
1. A composition which, when applied to a substrate and cured, provides a substantially water impervious coating on the substrate, comprising:
an effective amount of a high molecular weight polymeric material;
an effective amount of a curing agent;
an inorganic compound;
an effective amount of a coupling agent; and
an effective amount of an antioxidant;
wherein the effective amount of an antioxidant is an amount up to about 3% by weight of the total composition, and
wherein the antioxidant comprises one or more hindered-amine light stabilizers.
2. The composition of claim 1 , wherein the effective amount of the high molecular weight polymeric material is present in the composition in an amount from about 40% to about 95% by weight of the total composition.
3. The composition of claim 1 , wherein the effective amount of the high molecular weight polymeric material is present in the composition in an amount from about 60% to about 80% by weight of the total composition.
4. The composition of claim 1 , wherein the effective amount of the high molecular weight polymeric material is present in the composition in an amount of about 65% by weight of the total composition.
5. The composition of claim 1 , wherein the high molecular weight polymeric material is an ethylene-propylene polymeric material.
6. The composition of claim 5 , wherein the ethylene-propylene polymeric material is a randomly polymerized mixture of individual units of ethylene and propylene.
7. The composition of claim 6 , wherein the ethylene-propylene polymeric material is terpolymerized with at least one diene molecule to form an ethylene-propylene-diene molecule.
8. The composition of claim 7 , wherein the diene molecule is selected from the group consisting of ethylidene nobornene, dicyclopentadiene, butadiene, 1,4hexadiene and combinations thereof.
9. The composition of claim 1 , wherein the effective amount of the curing agent is in an amount from about 0.1 to about 3% by weight of the total composition.
10. The composition of claim 1 , where the curing agent is a radical producing curing agent.
11. The composition of claim 10 , wherein the radical producing curing agent is a peroxide.
12. The composition of claim 11 , wherein the peroxide is selected from the group consisting of diacyl peroxides, dialkyl peroxides, diperoxyketals, ketone peroxides, peroxydicarbonates, peroxyesters, and combinations thereof.
13. The composition of claim 11 , wherein the peroxide is selected from the group consisting of tert-butyl-peroxy-2-ethylhexylcarbonate, OO-(t-butyl) O-(2-ethylhexyl) monoperoxycarbonate, benzoyl peroxide, dicumyl peroxide, a-a′-bis(t-butylperoxy)diisopropylbenzene (Vulcup), 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, t-butylperoxy-diisopropyl benzene 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and combinations thereof.
14. The composition of claim 11 , wherein the peroxide is 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane.
15. The composition of claim 10 , wherein the radical producing curing agent is an azide.
16. The composition of claim 1 , wherein the inorganic compound is present in the composition in an amount of from about 1% to about 25% by weight of the total composition.
17. The composition of claim 1 , wherein the inorganic compound is selected from the group consisting of silica, titanium dioxide, barium sulfate, talc, carbon black, clay, limestone, and combinations thereof.
18. The composition of claim 1 , wherein the composition further comprises an adhesion promoting agent in an amount from about 0.05% to about 2% by weight of the total composition.
19. The composition of claim 18 , where the adhesion promoting agent is an unsaturated alkoxy silane.
20. The composition of claim 18 , wherein the adhesion promoting agent is an alkoxy silane selected from the group consisting of bis-trialkoxy silanes, amino-alkoxy silanes, phenyl alkoxy silanes, methoxy alkyl silanes, ethoxy alkyl silanes, and combinations thereof.
21. The composition of claim 19 , wherein the alkoxy silane is selected from the group consisting of glycidoxypropyltrimethoxy silane, phenyltriethoxy silane, vinyl trimethoxy silane, vinylbenzylated aminoethylaminopropyltrimethoxy silane, g-methacryloxypropyltrimethoxy silane, and combinations thereof.
22. The composition of claim 1 , further comprising an effective amount of a coupling coagent.
23. The composition of claim 22 , wherein the coupling coagent is present in the composition in an amount up to about 30% by weight of the total composition.
24. The composition according to claim 1 , wherein the coupling agent comprises a diacrylate.
25. The composition according to claim 24 , wherein the diacrylate comprises zinc diacrylate.
26. The composition of claim 1 , further comprising an effective amount of a colorant.
27. The composition of claim 1 , wherein each of the one or more hindered-amine light stabilizers is selected from the group consisting of Tinuvin 770 [bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate], Chimassorb 944 {Poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-s-triazine-2,4-diyl]-[(2,2-,6,6-tetramethyl-4-piperidyl)imino]-hexamethylene-[(2,2,6,6-tetramethyl-4-piperidyl)iminolli, Tinuvin 123 [Decanedioic acid, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)ester], Chimassorb 119 {1,3,5-Triazine-2,4,6-triamine, N,N′″-[1,2-ethanediylbis[[[4.6-bis[butyl(-1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1p-ropanediyl]]-bis[N′,N″-dibutyl-N′,N″-bis(1,2,2,6,6-pentamethyl-4-piperid-inyl)-}, and combinations thereof.
28. A composition suitable for encapsulation of photovoltaic components and which, when applied to a substrate and cured, provides UV stability, electrical insulation, mechanical protection, low tack, and corrosion protection, comprising:
a high molecular weight polymeric material in an amount from about 40% to about 95% by weight of the total composition;
a curing agent in an amount from about 0.1% to about 3% by weight of the total composition;
an inorganic compound in an amount up to about 35% by weight of the total composition;
a coupling agent in an amount from about 0.09% to about 5% by weight of the total composition;
a processing aid in an amount up to about 50% by weight of the total composition;
an adhesion promoting agent in an amount from about 0.05% to about 2% by weight of the total composition; and
an effective amount of an antioxidant;
wherein the effective amount of an antioxidant is an amount up to about 3% by weight of the total composition, and
wherein the antioxidant comprises one or more hindered-amine light stabilizers.
29. A photovoltaic module, comprising:
a glass plate;
photovoltaic cell circuitry; and
an encapsulant composition bonded to a portion of the glass plate and encapsulating at least a portion of the photovoltaic cell circuitry, the encapsulant composition comprising an effective amount of a high molecular weight polymeric material, an effective amount of a curing agent, an inorganic compound, an effective amount of a coupling agent, and an effective amount of an antioxidant;
wherein the effective amount of an antioxidant is an amount up to about 3% by weight of the total composition, and
wherein the antioxidant comprises one or more hindered-amine light stabilizers.