Conductive adhesives and biomedical articles including same

• US 7,620,439 B2
• Filed: 08/04/2005
• Issued: 11/17/2009
• Est. Priority Date: 08/04/2005
• Status: Active Grant

• Current Assignee: Solventum Intellectual Properties Company (Solventum Corp.)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Nelson, Carl T., Rizzardi, Don A., Menon, Vinod P., Kumar, Kanta
• Primary Examiner(s): Cohen; Lee S
• Application Number:
  US11/197,216
• Publication Number:
  US 20070032719A1
• Time in Patent Office: 1,566 Days
• Field of Search: 600391-392
• US Class Current: 600/391
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/0217 Electrolyte containing
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61N 1/0452 Specially adapted for transcutaneous muscle stimulation [TMS]
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives
• CPC Class Codes: C08K 5/19 Quaternary ammonium compounds
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• CPC Class Codes: C08L 33/14 of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: C09J 11/06 organic
• CPC Class Codes: C09J 133/04 Homopolymers or copolymers of esters C09J143/04 takes precedence
• CPC Class Codes: C09J 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 9/02 Electrically-conducting adhesives
• CPC Class Codes: H01B 1/20 Conductive material dispersed in non-conductive organic material organic macromolecular compounds or compositions C08

Abstract

A conductive adhesive composition is provided and articles that include the adhesive composition as a component thereof. The conductive adhesive composition comprises: (a) pressure sensitive adhesive; (b) electrolyte comprising water soluble or water dispersible organic chloride; and (c) humectant. In some embodiments, the conductive adhesive composition is a bicontinuous composition comprising an aqueous phase and an oil phase, and the bicontinuous composition may be derived from a polymerizable microemulsion composition, the microemulsion composition comprising: an aqueous phase comprising one or more hydrophilic monomers or oligomers and/or one or more amphiphilic monomers or oligomers in water, the water-soluble or water-dispersible organic chloride, surfactant and humectant; and an oil phase comprising one or more hydrophobic monomers or oligomers. Biomedical articles such as biomedical electrodes, may incorporate the foregoing adhesive as a component.

Claims

1. A conductive adhesive composition, comprising:

(a) pressure sensitive adhesive;

(b) electrolyte comprising water soluble or water dispersible organic chloride; and

(c) humectant,

wherein the electrolyte and the humectant are at least partially miscible in one another.

2. The conductive adhesive composition of claim 1 wherein the pressure sensitive adhesive is a bicontinuous composition comprising an aqueous phase and an oil phase.

3. The conductive adhesive composition of claim 2 wherein the bicontinuous composition is derived from a polymerizable microemulsion composition, the microemulsion composition comprising:

(a) an aqueous phase comprising one or more hydrophilic monomers or oligomers and/or one or more amphiphilic monomers or oligomers in water, the water-soluble or water-dispersible organic chloride, surfactant and humectant;

(b) an oil phase comprising one or more hydrophobic monomers or oligomers.

4. The conductive adhesive composition as in claim 3, wherein the organic chloride is present in an amount of up to about 20 parts by weight of the total aqueous phase.

5. The conductive adhesive composition as in claim 3, wherein the organic chloride is present in an amount from about 0.5 parts by weight to about 10 parts by weight based on 100 parts by weight of the total aqueous phase.

6. The conductive adhesive composition as in claim 3, wherein hydrophilic monomers and oligomers comprise ethylenically unsaturated, free radically (co)polymerizable, polar species.

7. The conductive adhesive composition as in claim 6, wherein hydrophilic monomers comprise water soluble, ethylenically unsaturated, free radically (co)polymerizable, polar, ionic or nonionic species that are substantially insoluble in the oil phase.

8. The conductive adhesive composition as in claim 7 wherein hydrophilic, water soluble, ethylenically unsaturated, free radically (co)polymerizable, polar, ionic monomers are selected from the group consisting of sodium styrene sulfonate, potassium acrylate, sodium acrylate, sodium methacrylate, ammonium acrylate, sodium 2-acrylamido-2-methylpropane sulfonate, 4,4,9-trimethyl-4-azonia-7-oxa-dec-9-ene-1-sulfonate, N,N-dimethyl-N-(beta-methacryloxyethyl)ammonium propionate betaine, trimethylamine methacrylamide, 1,1-dimethyl-1-(2,3-dihydroxypropyl)amine methacrylamide, and mixtures thereof.

9. The conductive adhesive composition as in claim 6 wherein hydrophilic oligomers are selected from the group consisting of polyethylene oxide acrylates, polyethylene oxide diacrylates, polyethylene glycol acrylates, polyethylene glycol diacrylates, polyurethane acrylates, polyurethane diacrylates, N-vinylpyrrolidone macromer, and mixtures of two or more of the foregoing.

10. The conductive adhesive composition as in claim 9 wherein the hydrophilic oligomers have a number average molecular weight from about 100 to about 100,000.

11. The conductive adhesive composition as in claim 9 wherein the amphiphilic monomers are selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, (meth)acrylic acid, hydroxyethyl (meth)acrylate, itaconic acid, styrene sulfonic acid, N-substituted acrylamides, N,N-disubstituted acrylamides, N,N-dimethylaminoethyl methacrylate, 2-acrylamido-2-methyl propane sulfonic acid, and mixtures thereof.

12. The conductive adhesive composition as in claim 3 wherein amphiphilic monomers comprise polar ethylenically-unsaturated free-radically (co)polymerizable species partitionable between the aqueous phase and the oil phase of the microemulsion.

13. The conductive adhesive composition as in claim 3 wherein hydrophilic or amphiphilic oligomers comprise polar ethylenically-unsaturated free-radically (co)polymerizable species which are substantially insoluble in the oil phase or which are both water soluble and oil soluble.

14. The conductive adhesive composition as in claim 13 wherein hydrophilic or amphiphilic oligomers are selected from the group consisting of polyethylene oxide acrylates, polyethylene oxide diacrylates, polyethylene glycol acrylates, polyethylene glycol diacrylates, polyurethane acrylates, polyurethane diacrylates, N-vinylpyrrolidone macromer, and mixtures of two or more of the foregoing.

15. The conductive adhesive composition as in claim 3 wherein the polymerizable microemulsion further comprises at least one initiator.

16. The conductive adhesive composition as in claim 3 wherein the hydrophobic monomers comprise free-radically polymerizable, ethylenically-unsaturated species selected from the group consisting of C₁ to C₁₈ alkyl esters of acrylic acid.

17. The conductive adhesive composition as in claim 16, wherein the hydrophobic monomer comprises one or more alkyl acrylate selected from the group consisting of isooctyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate and combinations of two or more of the foregoing.

18. The conductive adhesive composition as in claim 3 further comprising lipophilic additive.

19. The conductive adhesive composition as in claim 18 wherein the lipophilic additive comprises a free radically reactive, hydrophobic, crosslinking agent(s) selected from the group consisting of divinylbenzene, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,8-octanediol diacrylate;

and mixtures of two or more of the foregoing.

20. The conductive adhesive composition as in claim 18 wherein the lipophilic additive comprises a free radically reactive, hydrophobic, chain transfer agent selected from the group consisting of carbon tetrabromide, alcohol, mercaptan, and mixtures of two or more of the foregoing.

21. The conductive adhesive composition as in claim 20 wherein the chain transfer agent is isooctylthioglycolate.

22. The conductive adhesive composition as in claim 3 wherein the surfactant comprises a non-(co)polymerizable surfactant.

23. The conductive adhesive composition as in claim 3 wherein the surfactant comprises a polymerizable surfactant.

24. The conductive adhesive composition as in claim 3 wherein the surfactant is selected from nonionic, anionic and cationic.

25. The conductive adhesive composition of claim 2 wherein the bicontinuous composition is substantially non-porous.

26. The conductive adhesive composition as in claim 1, wherein the organic chloride comprises onium chloride selected from the group consisting of quaternary ammonium chloride, phosphonium chloride, oxonium chloride, sulfonium chloride or mixtures of two or more of the foregoing.

27. The conductive adhesive composition as in claim 26, wherein quaternary ammonium chloride is selected from the group consisting of hydroxyethyl-trimethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride tetraethylammonium chloride, acetamidopropyl trimethylammonium chloride, lactamidopropyl trimethylammonium chloride, dodecyl trimethylammonium chloride, hexadecyl trimethylammonium chloride, octadecyl trimethylammonium chloride, behenyl trimethylammonium chloride, coconut alkyl trimethylammonium chloride, tetradecyl dimethylbenzylammonium chloride, almondamidopropalkonium chloride, avocadamidopropalkonium chloride, bis-hydroxyethyl tallowmonium chloride, dibehenyldimonium chloride, diocodimonium chloride, didecyldimonium chloride, disoydimonium chloride, ditallowedimonium chloride, ditallowedimonium chloride, PPG-9 diethylmonium chloride, PPG-9 diethylmonium chloride, stearyl ethylhexyldimonium chloride, and combinations of two or more of the foregoing.

28. The conductive adhesive composition of claim 1, wherein the humectant is selected from the group consisting of glycerin, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, trimethylolpropane, ethylene glycol and combinations of two or more of the foregoing.

29. The conductive adhesive composition of claim 1 wherein the humectant is given by the formula:

MO(CH₂CH₂O)_mH

wherein

M is selected from the group consisting of hydrogen and C₁ through C₆ alkyl; and

m is an integer of about 1 to about 25.

30. The conductive adhesive composition of claim 1 wherein the pressure sensitive adhesive is a hydrogel.

31. A biomedical electrode, comprising:

(a) a conductor member; and

(b) a conductive adhesive composition associated with the conductor member, the conductive adhesive composition, comprising;

(i) pressure sensitive adhesive;

(ii) electrolyte comprising water soluble or water dispersible organic chloride; and

(iii) humectant,

wherein the electrolyte and the humectant are at least partially miscible in one another.

32. A biomedical electrode as in claim 31, wherein the conductor member comprises a backing and a conductive component associated with the backing;

the conductive adhesive composition comprising first and second major surfaces, the first major surface of the conductive adhesive operatively associated with the conductive component so that electrical current is able to pass through the conductive adhesive to the conductive component or through the conductive component to the conductive adhesive.

33. A biomedical electrode as in claim 32 further comprising a release liner over the second major surface of the conductive adhesive.

34. A biomedical electrode as in claim 33 wherein the release liner comprises a polymeric backing and a fluorochemical release coating over the polymeric backing.

35. A biomedical electrode as in claim 34 wherein the polymeric backing of the release liner comprises polyester.

36. A biomedical electrode as in claim 31 wherein the pressure sensitive adhesive is a bicontinuous composition derived from a polymerizable microemulsion composition, the microemulsion composition comprising:

(a) an aqueous phase comprising one or more hydrophilic monomers or oligomers and/or one or more amphiphilic monomers or oligomers in water, the water-soluble or water-dispersible organic chloride, and humectant;

(b) an oil phase comprising one or more hydrophobic monomers or oligomers.

37. A biomedical electrode as in claim 36 wherein the bicontinuous composition is substantially non-porous.

38. A biomedical electrode as in claim 36, wherein the organic chloride comprises onium chloride selected from the group consisting of quaternary ammonium chloride, phosphonium chloride, oxonium chloride, sulfonium chloride or mixtures of two or more of the foregoing.

39. A biomedical electrode as in claim 38, wherein quaternary ammonium chloride is selected from the group consisting of hydroxyethyl-trimethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride tetraethylammonium chloride, acetamidopropyl trimethylammonium chloride, lactamidopropyl trimethylammonium chloride, dodecyl trimethylammonium chloride, hexadecyl trimethylammonium chloride, octadecyl trimethylammonium chloride, behenyl trimethylammonium chloride, coconut alkyl trimethylammonium chloride, tetradecyl dimethylbenzylammonium chloride, almondamidopropalkonium chloride, avocadamidopropalkonium chloride, bis-hydroxyethyl tallowmonium chloride, dibehenyldimonium chloride, diocodimonium chloride, didecyldimonium chloride, disoydimonium chloride, ditallowedimonium chloride, ditallowedimonium chloride, PPG-9 diethylmonium chloride, PPG-9 diethylmonium chloride, stearyl ethylhexyldimonium chloride, and combinations of two or more of the foregoing.

40. A biomedical electrode as in claim 36 wherein hydrophilic monomers and oligomers comprise ethylenically unsaturated, free radically (co)polymerizable, polar species.

41. A biomedical electrode as in claim 40, wherein hydrophilic monomers comprise water soluble, ethylenically unsaturated, free radically (co)polymerizable, polar, ionic or nonionic species that are substantially insoluble in the oil phase.

42. A biomedical electrode as in claim 41, wherein hydrophilic, water soluble, ethylenically unsaturated, free radically (co)polymerizable, polar, ionic monomers are selected from the group consisting of sodium styrene sulfonate, potassium acrylate, sodium acrylate, sodium methacrylate, ammonium acrylate, sodium 2-acrylamido-2-methylpropane sulfonate, 4,4,9-trimethyl-4-azonia-7-oxa-dec-9-ene-1-sulfonate, N,N-dimethyl-N-(beta methacryloxyethyl)ammonium propionate betaine, trimethylamine methacrylamide, 1,1-dimethyl-1-(2,3-dihydroxypropyl)amine methacrylamide, and mixtures thereof.

43. A biomedical electrode as in claim 40, wherein hydrophilic oligomers are selected from the group consisting of polyethylene oxide acrylates, polyethylene oxide diacrylates, polyethylene glycol acrylates, polyethylene glycol diacrylates, polyurethane acrylates, polyurethane diacrylates, N-vinylpyrrolidone macromer, and mixtures of two or more of the foregoing.

44. A biomedical electrode as in claim 36, wherein amphiphilic monomers comprise polar ethylenically-unsaturated free-radically (co)polymerizable species partitionable between the aqueous phase and the oil phase of the microemulsion.

45. A biomedical electrode as in claim 44, wherein the amphiphilic monomers are selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, (meth)acrylic acid, hydroxyethyl (meth)acrylate, itaconic acid, styrene sulfonic acid, N-substituted acrylamides, N,N-disubstituted acrylamides, N,N-dimethylaminoethyl methacrylate, 2-acrylamido-2-methyl propane sulfonic acid, and mixtures thereof.

46. A biomedical electrode as in claim 36 wherein hydrophilic or amphiphilic oligomers comprise polar ethylenically-unsaturated free-radically (co)polymerizable species which are substantially insoluble in the oil phase or which are both water soluble and oil soluble.

47. A biomedical electrode as in claim 46, wherein hydrophilic or amphiphilic oligomers are selected from the group consisting of polyethylene oxide acrylates, polyethylene oxide diacrylates, polyethylene glycol acrylates, polyethylene glycol diacrylates, polyurethane acrylates, polyurethane diacrylates, N-vinylpyrrolidone macromer, and mixtures of two or more of the foregoing.

48. A biomedical electrode as in claim 36, wherein the hydrophobic monomers comprise free-radically polymerizable, ethylenically-unsaturated species selected from the group consisting of C₁ to C₁₈ alkyl esters of acrylic acid.

49. A biomedical electrode as in claim 48, wherein the hydrophobic monomer comprises one or more alkyl acrylate selected from the group consisting of isooctyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate and combinations of two or more of the foregoing.

50. A biomedical electrode as in claim 36, wherein the humectant is selected from the group consisting of glycerin, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, trimethylol propane, ethylene glycol and combinations of two or more of the foregoing.

51. A biomedical electrode as in claim 36, wherein the humectant is given by the formula:

MO(CH₂CH₂O)_mH

wherein

M is selected from the group consisting of hydrogen and C₁ through C₆ alkyl; and

m is an integer of about 1 to about 25.

52. A biomedical electrode as in claim 36 further comprising lipophilic additive.

53. A biomedical electrode as in claim 52, wherein the lipophilic additive comprises a free radically reactive, hydrophobic, crosslinking agent(s) selected from the group consisting of divinylbenzene, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,8-octanediol diacrylate;

and mixtures of two or more of the foregoing.

54. A biomedical electrode as in claim 52, wherein the lipophilic additive comprises a free radically reactive, hydrophobic, chain transfer agent selected from the group consisting of carbon tetrabromide, alcohol, mercaptan, and mixtures of two or more of the foregoing.

55. A biomedical electrode as in claim 54, wherein the chain transfer agent is isooctylthioglycolate.

56. A biomedical electrode as in claim 36, wherein surfactant comprises non (co)polymerizable surfactant.

57. A biomedical electrode as in claim 36, wherein the surfactant comprises polymerizable surfactant.

58. A biomedical electrode as in claim 36, wherein the surfactant is selected from nonionic, anionic and cationic surfactants.

59. The conductive adhesive composition of claim 31 wherein the pressure sensitive adhesive is a hydrogel.