Method of making electrical devices having an oxygen barrier coating
View Patent ↗An electrical device includes two electrodes and a conductive polymer layer, containing a mixture of a polymer and a conductive filler, separating the electrodes. A oxygen barrier material containing a thermosetting polymer component is present on the exposed surface of the conductive polymer layer that is not in contact with the laminar electrodes. The oxygen barrier material may be a polyamine-polyepoxide material, and may provide for acceptable barrier properties over a wide range of humidity levels.
1. A method of making an electrical device, comprising:
forming a laminate of a conductive polymer layer, a first electrode, and a second electrode, the conductive polymer layer comprising a mixture of a polymer and a conductive filler, and the laminate comprising an exposed surface between the first and second electrodes; and
covering at least a portion of the exposed surface of the conductive polymer layer with a thermoset oxygen barrier material comprising a thermosetting polymer component, at least 65 weight percent of said polymer component comprising two or more groups selected from the group consisting of >N—CH 2 -Aryl-CH 2 —N<, >N-Aryl-N<, —O-Aryl-O—, —O(O═)C-Aryl-C(═O)O—, —O(O═)C—CH 2 -Aryl-CH 2 —C(═O)O—, and —CH 2 —CH(OH)—CH 2 —; wherein -Aryl- is selected from the group consisting of phenylene, naphthylene and anthracenyl.
2. The method of claim 1 , wherein the covering at least a portion of the exposed surface comprises contacting at least a portion of the region between the first and second electrodes with a mixture of a polyamine and a polyepoxide, and curing the mixture to form a polyamine-polyepoxide material that is a thermoset oxygen barrier.
3. The method of claim 2 , further comprising repeating the contacting at least a portion of the region with a mixture of a polyamine and a polyepoxide, and the curing the mixture to form a polyamine-polyepoxide material.
4. The method of claim 2 , wherein the mixture of the polyamine and polyepoxide further comprises a solvent.
5. The method of claim 2 , wherein the mixture of the polyamine and polyepoxide further comprises a platelet-type filler.
6. The method of claim 1 , wherein -Aryl- is selected from the group consisting of meta-phenylene and 2,6-naphthalene.
7. The method of claim 1 , wherein the conductive filler comprises nickel.
8. The method of claim 1 , wherein at least 90% of the exposed surface of the conductive polymer layer is covered by the oxygen barrier material.
9. The method of claim 1 , wherein at least 99% of the exposed surface of the conductive polymer layer is covered by the oxygen barrier material.
10. The method of claim 1 , wherein at 100% of the exposed surface of the conductive polymer layer is covered by the oxygen barrier material.
11. The method of claim 1 , wherein the covering at least a portion of the exposed surface comprises encapsulating the laminate.