Electronic devices comprising butyl rubber

Abstract

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.

What is claimed: 
     
         1 . An electrical device comprising a substrate layer, a conductive layer and an encapsulant layer, wherein at least the encapsulant layer comprises cured butyl rubber. 
     
     
         2 . The device of  claim 1 , wherein the device exhibits an increase in electrical resistance of less than 360% following exposure to nitric acid vapour for 12 hours or hydrochloric acid vapour for 10 hours. 
     
     
         3 . The device of  claim 1  or  2 , 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. 
     
     
         4 . The device of any one of  claims 1  to  3 , wherein the conductive layer comprises silver. 
     
     
         5 . The device of any one of  claims 1  to  3 , wherein the conductive layer comprises indium tin oxide. 
     
     
         6 . The device of any one of  claims 1  to  5 , wherein the substrate layer comprises glass. 
     
     
         7 . The device of any one of  claims 1  to  6 , wherein the encapsulant layer comprises a filler. 
     
     
         8 . The device of any one of  claims 1  to  7 , wherein the encapsulant layer comprises a butyl rubber comprising repeating units derived from at least one isoolefin monomer and repeating units derived from one or more multiolefin monomers. 
     
     
         9 . The device of  claim 8 , wherein the encapsulant layer comprises a butyl rubber comprising repeating units derived from at least one isoolefin monomer and repeating units derived from the reaction product, following halogenation, of one or more multiolefin monomers and at least one nitrogen or phosphorous based nucleophile comprising a pendant vinyl group. 
     
     
         10 . The device of  claim 8  or  9 , wherein the isoolefin monomer comprises a C 4  to C 8  isomonoolefin monomer. 
     
     
         11 . The device of  claim 10 , wherein the isoolefin monomer comprises isobutylene. 
     
     
         12 . The device of any one of  claims 8  to  11 , wherein the multiolefin monomer comprises a C 5  to C 11  conjugated aliphatic diene monomer. 
     
     
         13 . The device of  claim 12 , wherein the multiolefin monomer comprises isoprene. 
     
     
         14 . The device of any one of  claims 8  to  13 , wherein the multiolefin monomer is present in a total amount of from 0.5-2.5 mol % prior to halogenation. 
     
     
         15 . The device of any one of  claims 8  to  14 , wherein the butyl rubber ionomer further comprises one or more co-polymerizable alkyl-substituted vinyl aromatic co-monomers. 
     
     
         16 . The device of  claim 15 , wherein the co-monomer comprises a C 1 -C 4  alkyl substituted styrene. 
     
     
         17 . The device of  claim 16 , wherein the co-monomer comprises α-methyl styrene, p-methyl styrene, chlorostyrene, cyclopentadiene or methylcyclopentadiene. 
     
     
         18 . The device of  claim 9 , 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  or R 3  contains a pendant vinyl group. 
       
     
     
         19 . The device of  claim 18 , 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. 
     
     
         20 . The device of  claim 19 , wherein the nucleophile comprises diphenylphosphinostyrene DPPS.