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. An electrical device, comprising:
a first electrode;
a second electrode;
a conductive polymer layer separating the first and second electrodes, said conductive polymer layer (i) having an exposed surface not in contact with the first and second electrodes, and (ii) comprising a mixture of a polymer and a particulate conductive filler which comprises nickel; and
a thermoset oxygen barrier material comprising a thermosetting polymer component on the exposed surface of the conductive polymer layer, at least 65 weight percent of the polymer component of the oxygen barrier material 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 —; -Aryl- being selected from the group consisting of phenylene, naphthylene and anthracenyl.
2. The electrical device of claim 1 , wherein the oxygen permeability constant of the oxygen barrier material is less than 0.60 cc·mil/100 in 2 ·atm·day.
3. The electrical device of claim 1 , wherein the oxygen permeability constant of the oxygen barrier material is less than 0.50 cc·mil/100 in 2 ·atm·day.
4. The electrical device of claim 1 , wherein the oxygen permeability constant of the oxygen barrier material is less than 0.30 cc·mil/100 in 2 ·atm·day.
5. The electrical device of claim 1 , wherein the oxygen permeability constant of the oxygen barrier material is less than 1 cc·mil/100 in 2 ·atm·day, when in an environment of 75% relative humidity.
6. The electrical device of claim 1 , wherein the oxygen barrier material covers at least 90% of the exposed surface of the conductive polymer layer.
7. The electrical device of claim 1 , wherein the oxygen barrier material covers at least 99% of the exposed surface of the conductive polymer layer.
8. The electrical device of claim 1 , wherein the oxygen barrier material covers 100% of the exposed surface of the conductive polymer layer.
9. The electrical device of claim 1 , wherein the device is encapsulated by the oxygen barrier material.
10. The electrical device of claim 1 , wherein the oxygen barrier material comprises a polyamine-polyepoxide material.
11. The electrical device of claim 1 , wherein -Aryl- is selected from the group consisting of meta-phenylene and 2,6-naphthalene.
12. The electrical device of claim 1 , wherein at least 80 weight percent of the polymer component of the oxygen barrier material comprises 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.
13. The electrical device of claim 12 , wherein -Aryl- is selected from the group consisting of meta-phenylene and 2,6-naphthalene.
14. The electrical device of claim 1 , wherein at least 95 weight percent of the polymer component of the oxygen barrier material comprises 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.
15. The electrical device of claim 14 , wherein -Aryl- is selected from the group consisting of meta-phenylene and 2,6-naphthalene.
16. The electrical device of claim 1 , wherein the oxygen barrier material comprises from 2 to 40 weight percent of a platelet-type filler.
17. The electrical device of claim 1 , having a resistance of less than 15 milliohms.
18. An electrical device, comprising:
a first electrode, a second electrode, and a conductive polymer layer separating the first and second electrodes and having an exposed surface not in contact with the first and second electrodes;
the conductive polymer layer comprising a mixture of a polymer and a particulate conductive filler comprising nickel; and
a thermoset polyamine-polyepoxide oxygen barrier comprising a thermosetting polymer component on at least 90% of the exposed surface of the conductive polymer layer;
at least 65 weight percent of the polymer component of the oxygen barrier material 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.