Electrically conductive compositions and electrodes utilizing same

Claim 1

An electrically conductive, adhesive, cohesive composition characterized by: an interpenetrating polymer network essentially including two components: a first polymeric constituent which is crosslinked and hydrophilic and a second polymeric constituent which is hydrophilic and not crosslinked, the network being comprised of at least about 35% of the first constituent; humectant; and water. 2. The composition of claim 1 wherein the interpenetrating network comprises an amount of the first polymeric constituent in excess of about 50% and preferably between about 80% and 90%. 3. The composition of claim 1 or 2 wherein the interpenetrating polymer network comprises about 25% to 70% of the overall composition. 4. The composition of any one of the preceding claims wherein the amount of the humectant is about 5% to 50%. 5. The composition of any one of the preceding claims wherein the first polymeric constituent is a hydroxymethylmethacrylate polymer. 6. The composition of any one of claims 1 to 4 wherein the first polymeric constituent is a potassium acrylate polymer. 7. The composition of any one of claims 1 to 4 wherein the first polymeric constituent is an N-sulfohydrocarbon substituted acrylamide polymer. 8. The composition of any one of claims 1 to 4 wherein the second polymeric constituent is polyacrylic acid. 9. An adhesive, electrically conductive composition, characterized by essentially including between about 25% and about 75% of an interpenetrating polymer network formed as the result of the polymerization and cross-linking of 2-acrylamido-2-methylpropanesulfonic acid or one of its salts in the presence of a hydrophilic polymer which is not cross-linked, and including between about 5% to about 50% of a humectant, the balance being substantially water. 10. The composition of claim 9 wherein a salt form of the 2-acrylamido-2-methylpropanesulfonic acid is polymerized. 11. The composition of claim 10 wherein the salt is a sodium salt. 12. The composition of any one of claims 9 to 11 wherein the amount of the polymer network is about 50%. 13. The composition of any one of claims 9 to 12 wherein the hydrophilic polymer is polyacrylic acid. 14. The composition of claim 13 wherein the molecular weight of the polyacrylic acid is about 5,000. 15. The composition of any one of the preceding claims wherein the humectant is glycerol. 16. The composition of any one of claims 1 to 14 wherein the humectant is propylene glycol, polyethylene glycol or sorbitol. 17. The composition of any one of the preceding claims wherein the amount of the humectant is about 30%. 18. An electrically conductive, adhesive, conformable and flexible, cohesive body, characterized by: an interpenetrating polymer network essentially including two components: polymerized and crosslinked 2-acrylamido-2-methylpropanesulfonic acid, its salts or copolymers of the acid or its salts as the first component and, as the second component, an organic, hydrophilic polymer which is not cross-linked, the amounts of the first component and the second component in terms of overall composition ranging from about 24% to 74% and 1% to 40%, respectively; a humectant ranging in amount from about 5% to 50%, and water, substantially the balance. 19. The body of claim 18 wherein the amounts of the two polymer network components are about 45% and 10%, respectively. 20. The body of claim 18 or 19 wherein the amount of the humectant is about 30%. 21. The body of any one of claims 18 to 20 wherein the amount of the interpenetrating polymer network is about 25% to 75% and preferably about 50%. 22. The body of any one of claims 18 to 21 wherein the first component is a polymerized salt of 2-acrylamido-2-methylpropanesulfonic acid. 23. The body of claim 22 wherein the salt is a sodium salt. 24. The body of any one of claims 18 to 23 wherein the second component is polyacrylic acid. 25. The body of claim 24 wherein the molecular weight of the polyacrylic acid is about 5,000. 26. An electrically conductive, adhesive, cohesive body, characterized in that the body comprises predominately the composition according to claim 1. 27. The body of claim 26 wherein the interpenetrating polymer network comprises at least about 50% of the crosslinked polymer. 28. The body of claim 27 wherein the amount is about 80% to 90% and the second component comprises substantially the balance of the network. 29. The body of claim 14 wherein the humectant is glycerol. 30. The body of claim 14 wherein the humectant is propylene glycol, sorbitol or polyethylene glycol. 31. An adhesive electrode for establishing electrical contact with a surface, comprising: support means and terminal means for connection to external electrical circuit means, and an adhesive, conductive body as defined in claim 26 for electrically interfacing with the surface to be contacted, the body being contacted by the support means and being in electrical communication with the terminal means. 32. The electrode of claim 31 wherein the composition includes as the two components: polymerized crosslinked 2-acrylamido-2-methylpropanesulfonic acid, its salts or copolymers of the acid or its salts as the first component and an organic, non-crosslinked hydrophilic polymer, as the second polymeric component, the overall amounts of the first and second components ranging from about 24% to 74% and 1% to 40%, respectively. 33. The electrode of claim 32 wherein the first component is a polymerized salt form of the 2-acrylamido-2-methylpropanesulfonic acid. 34. The electrode of claim 33 wherein the salt is a sodium salt. 35. The electrode of any one of claims 32 to 34 wherein the hydrophilic polymer is polyacrylic acid. 36. The electrode of claim 35 wherein the molecular weight of the polyacrylic acid is about 5,000. 37. The electrode of any one of claims 31 to 36 wherein the humectant is glycerol. 38. The electrode of any one of claims 31 to 36 wherein the humectant is propylene glycol, sorbitol or polyethylene glycol. 39. The electrode of any one of claims 31 to 38 wherein the amount of the humectant is about 30%.