Electronic devices comprising butyl rubber
This invention relates to elastomeric coatings for electronics. Disclosed is a electronic device comprising a substrate layer, a conductive layer and an encapsulant layer. The encapsulant layer comprises at least a butyl rubber material. The butyl rubber encapsulant prevents a change in resistivity of the conductive layer following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours.
1. An electrical device comprising:
a substrate,
an electrically conductive layer disposed on the substrate and having an electrical resistance to flow of electricity therethrough, and
an encapsulant layer disposed over at least the conductive layer to inhibit contact of moisture and gas with the electrically conductive layer, wherein the encapsulant layer comprises cured butyl rubber ionomer, the butyl rubber ionomer comprising a reaction product of:
at least one nitrogen or phosphorous based nucleophile comprising a pendant vinyl group, and
a halogenated copolymer derived from an olefinic copolymer comprising repeat units derived from at least one isoolefin monomer and repeat units derived from one or more multiolefin monomers in an amount of 0.5 to 2.5 mole percent, based on the total number of monomers in the olefinic copolymer,
wherein the reaction product includes 0.5 to 4 molar equivalents of the at least one nitrogen or phosphorous based nucleophile;
wherein the device exhibits an increase in electrical resistance of less than 100% following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours.
2. The device of claim 1 , wherein the device exhibits a change in optical transmittance at 365 nm of less than 15% following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours.
3. The device of claim 1 , wherein the electrically conductive layer comprises at least one of: silver and indium tin oxide.
4. The device of claim 1 , wherein the substrate-comprises glass.
5. The device of claim 1 , wherein the butyl rubber comprises a filler.
6. The device of claim 1 , wherein:
the isoolefin monomer comprises a C 4 to C 8 isomonoolefin monomer; and
the multiolefin monomer comprises a C 5 to C 11 conjugated aliphatic diene monomer.
7. The device of claim 6 , wherein:
the isoolefin monomer comprises isobutylene; and
the multiolefin monomer comprises isoprene.
8. The device of claim 1 , wherein the wherein an amount of ionomeric moiety in the butyl rubber ionomer is at least 0.75 mol %.
9. The device of claim 1 , wherein the butyl rubber ionomer further comprises one or more co-polymerizable alkyl-substituted vinyl aromatic co-monomers.
10. The device of claim 9 , wherein the co-monomer comprises a C 1 -C 4 alkyl substituted styrene.
11. The device of claim 10 , wherein the co-monomer comprises α-methyl styrene, p-methyl styrene, chlorostyrene, cyclopentadiene or methylcyclopentadiene.
12. The device of claim 1 , wherein the nitrogen or phosphorous based nucleophile is selected according to the formula,
wherein:
A is nitrogen or phosphorus; and, R 1 , R 2 and R 3 are independently selected and comprise: linear or branched C 1 -C 18 alkyl substituents; an aryl substituent which is monocyclic or composed of fused C 4 -C 8 rings; or, combinations thereof, wherein at least one of R 1 , R 2 and R 3 contains a pendant vinyl group.
13. The device of claim 12 , wherein the nucleophile is selected from the group consisting of diphenylphosphinostyrene (DPPS), allyldiphenylphosphine, diallylphenylphosphine, diphenylvinylphosphine, triallylphenylphosphine, N-vinyl caprolactam, N-vinyl phthalimide, 9-vinyl carbazole, N-[3-(dimethylamino)propyl]methacrylamide, diphenylvinylphsophin-methyl-N-vinylacetamide, N-allyl-N-butyl-2-propen-1-amine, 1-vinyl-2-pyrrolidone, 2-Isopropenyl-2-oxazoline, 2-vinylpyrid-4-vinylpyridine, N-ethyl-2-vinylcarbazole and mixtures thereof.
14. The device of claim 13 , wherein the nucleophile comprises diphenylphosphinostyrene (DPPS).
15. The device of claim 12 , wherein:
the isoolefin monomer comprises a C 4 to C 8 isomonoolefin monomer;
the multiolefin monomer comprises a C 5 to C 11 conjugated aliphatic diene monomer; and
the nucleophile is selected from the group consisting of diphenylphosphinostyrene (DPPS), allyldiphenylphosphine, diallylphenylphosphine, diphenylvinylphosphine, triallylphenylphosphine, N-vinyl caprolactam, N-vinyl phthalimide, 9-vinyl carbazole, N-[3-(dimethylamino)propyl]methacrylamide, diphenylvinylphsophin-methyl-N-vinylacetamide, N-allyl-N-butyl-2-propen-1-amine, 1-vinyl-2-pyrrolidone, 2-Isopropenyl-2-oxazoline, 2-vinyl pyrid-4-vinylpyridine, N-ethyl-2-vinylcarbazole and mixtures thereof.
16. The device of claim 15 , wherein:
the isoolefin monomer comprises isobutylene;
the multiolefin monomer comprises isoprene; and
the nucleophile comprises diphenylphosphinostyrene (DPPS).
17. The device of claim 16 , wherein the butyl rubber further comprises one or more co-polymerizable co-monomers selected from the group consisting of: α-methyl styrene, p-methyl styrene, chlorostyrene, cyclopentadiene or methylcyclopentadiene.
18. The device of claim 1 , wherein the encapsulant layer is a cured layer laminated onto the substrate and/or the electrically conductive layer, optionally using an adhesive.
19. An electrical device comprising:
a substrate,
an electrically conductive layer disposed on the substrate and having an electrical resistance to flow of electricity therethrough, and
an encapsulant layer disposed over at least the conductive layer to inhibit contact of moisture and gas with the electrically conductive layer, wherein the encapsulant layer comprises cured butyl rubber ionomer, the butyl rubber ionomer comprising a reaction product of:
at least one phosphorous based nucleophile comprising a pendant vinyl group, and
a brominated copolymer derived from an olefinic copolymer consisting of:
i. repeat units derived from at least one isoolefin monomer including isobutylene;
ii. repeat units derived from one or more multiolefin monomers in an amount of 0.5 to 2.5 mole percent, based on the total number of monomers in the olefinic copolymer and including isoprene, and
iii. optionally one or more co-polymerizable alkyl-substituted vinyl aromatic co-monomers selected from the group consisting of α-methyl styrene, p-methyl styrene, chlorostyrene, cyclopentadiene and methylcyclopentadiene;
wherein the reaction product includes 0.5 to 4 molar equivalents of the at least one phosphorous based nucleophile;
wherein the device exhibits an increase in electrical resistance of less than 100% following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours; and the device exhibits a change in optical transmittance at 365 nm of less than 15% following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours.
20. The device of claim 19 , wherein the wherein an amount of ionomeric moiety in the butyl rubber ionomer is at least 0.75 mol % and the nucleophile comprises diphenylphosphinostyrene (DPPS).