Electrically-conductive, pressure-sensitive adhesive and biomedical electrodes

Claim 2

A composition comprising: a conformable, cohesive, adhesive copolymer matrix formed by free radical polymerizing an adhesive precursor comprising a carboxylic acid as a water-soluble hydrogen bond donating monomer, N-vinyl pyrrolidone as a water-soluble hydrogen bond accepting monomer, and a polymerization initiator, wherein the molar ratio of hydrogen bond accepting sites to hydrogen bond donating sites available on the monomers is from about 1:3 to about 6:1 and wherein the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1; and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble, polar organic compound, about 2 to 100% by weight water, and about 0 to 12% by weight water-soluble salt; wherein the composition contains from about 12% to about 50% by weight non-volatile copolymer matrix, the hydrogen bond donating sites on the copolymer matrix are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive.

Claim 3

The composition of claim 1 wherein the copolymer matrix is covalently crosslinked and the adhesive precursor further comprises a multifunctional crosslinker present up to about 2.5% by weight of the total monomers in the adhesive precursor.

Claim 4

The composition of claim 1 wherein the hydrogen bond donating monomer is selected from the group of carboxylic acids consisting of α,β-ethylenically unsaturated carboxylic acids having up to eight carbon atoms.

Claim 5

The composition of claim 1 wherein the hydrogen bond donating monomer is acrylic acid and the final composition comprises from about 15% to about 25% by weight copolymer matrix.

Claim 6

The composition of claim 1 wherein the water-soluble, polar organic compound is selected from a group consisting of monomeric and polymeric polyhydric alcohols.

Claim 7

The composition of claim 1 wherein the water-soluble polar organic compound is glycerol.

Claim 8

The composition of claim 1 wherein the soluble salt is a chloride, bromide, or iodide salt of sodium or potassium and comprises from 0 to 6% by weight of the plasticizing, electrically-conductive solution.

Claim 9

The composition of claim 1 wherein the soluble salt is potassium chloride and it comprises about 1.25% by weight of the plasticizing, electrically-conductive solution.

Claim 10

An electrically-conductive, pressure-sensitive adhesive formed by the free radical copolymerization of an adhesive precursor comprising: a carboxylic acid as a water-soluble hydrogen bond donating monomer; N-vinyl pyrrolidone as a water-soluble hydrogen bond accepting monomer; a free radical initiator; and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble, polar organic compound, from about 2 to 100% by weight water, and from about 0 to 12% by weight soluble salt; wherein the ratio of hydrogen bond accepting sites to hydrogen bond donating sites on the monomers is from about 1:3 to about 6:1, the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, the adhesive precursor contains from about 12% to about 50% by weight total monomers, the acid sites on the hydrogen bond donating monomer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive.

Claim 11

An electrically-conductive, pressure-sensitive adhesive formed by the free radical copolymerization of an adhesive precursor comprising: a carboxylic acid as a water-soluble hydrogen bond donating monomer; N-vinyl pyrrolidone as a water-soluble hydrogen bond accepting monomer; a free radical initiator; and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble, polar organic compound, from about 2 to 100% by weight water, and from about 0 to 12% by weight soluble salt; wherein the ratio of hydrogen bond accepting sites to hydrogen bond donating sites on the monomers is from about 1:3 to about 6:1, the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, the adhesive precursor contains from about 12% to about 50% by weight total monomers, the acid sites on the hydrogen bond donating monomer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive.

Claim 12

The composition of claim 9 wherein the adhesive precursor further comprises a multifunctional crosslinker present up to about 2.5% by weight of the total monomers in the adhesive precursor.

Claim 13

The composition of claim 9 wherein the hydrogen bond donating monomer is selected from the group of carboxylic acids consisting of α,β-ethylenically unsaturated carboxylic acids having up to eight carbon atoms.

Claim 14

The composition of claim 9 wherein the adhesive precursor comprises by weight: from about 5% to 43.5% acrylic acid, from about 7% to 45% N-vinylpyrrolidone, from about 0.05% to 0.3% triethylene-glycol-bis-methacrylate, from about 0.02% to 0.1% benzildimethylketal, from about 5% to 60% water, from about 0.5% to 12% potassium chloride, and from about 30% to 70% glycerol; and wherein the acrylic acid is from about 5% to about 80% neutralized with sodium hydroxide.

Claim 15

The composition of claim 3 wherein the adhesive precursor comprises by weight from about 8% to 12% acrylic acid from about 8% to 12% N-vinylpyrrolidone from about 0.10% to 0.15% triethylene-glycol-bis-methacrylate from about 0.05% to 0.07% benzildimethylketal from about 23% to 27% water from about 0.75% to 1.25% potassium chloride from about 48% to 52% glycerol, and the acrylic acid is from about 45% to 55% neutralized with sodium hydroxide.

Claim 16

A process for making an electrically-conductive, pressure-sensitive adhesive comprising: (a) providing an adhesive precursor comprising a carboxylic acid as a hydrogen bond donating monomer, N-vinyl pyrrolidone as a hydrogen bond accepting monomer, a free radical initiator, and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble organic compound, from about 2 to 100% by weight water, and from about 0 to 12% by weight soluble salt; wherein the ratio of hydrogen bond accepting sites to hydrogen bond donating sites on the monomers is from about 1:3 to about 6:1, the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, the adhesive precursor contains from about 12% to about 50% by weight of total monomers, the hydrogen bond donating sites on the hydrogen bond donating monomer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive; (b) coating the adhesive precursor on a substrate; and (c) initiating copolymerization of the monomers in the adhesive precursor.

Claim 17

A process for making an electrically-conductive, pressure-sensitive adhesive comprising: (a) providing an adhesive precursor comprising a carboxylic acid as a hydrogen bond donating monomer, N-vinyl pyrrolidone as a hydrogen bond accepting monomer, a free radical initiator, and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble organic compound, from about 2 to 100% by weight water, and from about 0 to 12% by weight soluble salt; wherein the ratio of hydrogen bond accepting sites to hydrogen bond donating sites on the monomers is from about 1:3 to about 6:1, the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, the adhesive precursor contains from about 12% to about 50% by weight of total monomers, the hydrogen bond donating sites on the hydrogen bond donating monomer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive; (b) coating the adhesive precursor on a substrate; and (c) initiating copolymerization of the monomers in the adhesive precursor.

Claim 18

A biomedical electrode comprising: an electrical conductor, means integrally associated with the conductor for connecting the electrode to an electromedical instrument, an electrically-conductive, pressure-sensitive adhesive in electrical contact with the conductor comprising a conformable, cohesive, adhesive copolymer matrix formed by free radical polymerizing an adhesive precursor comprising a carboxylic acid as a water-soluble hydrogen bond donating monomer, N-vinyl pyrrolidone as a water-soluble hydrogen bond accepting monomer, and a polymerization initiator, wherein the molar ratio of hydrogen bond accepting sites to hydrogen bond donating sites available on the monomers is from about 1:3 to about 6:1 and wherein the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble, polar organic compound, about 2 to 100% by weight water, and about 0 to 12% by weight water-soluble salt; wherein the electrically-conductive, pressure-sensitive adhesive contains from about 12% to about 50% by weight non-volatile copolymer matrix, the hydrogen bond donating sites on the copolymer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive.

Claim 19

A biomedical electrode comprising: an electrical conductor, means integrally associated with the conductor for connecting the electrode to an electromedical instrument, an electrically-conductive, pressure-sensitive adhesive in electrical contact with the conductor comprising a conformable, cohesive, adhesive copolymer matrix formed by free radical polymerizing an adhesive precursor comprising a carboxylic acid as a water-soluble hydrogen bond donating monomer, N-vinyl pyrrolidone as a water-soluble hydrogen bond accepting monomer, and a polymerization initiator, wherein the molar ratio of hydrogen bond accepting sites to hydrogen bond donating sites available on the monomers is from about 1:3 to about 6:1 and wherein the weight ratio of carboxylic acid to N-vinyl pyrrolidone is from about 1:2 to about 3:1, and a plasticizing, electrically-conductive solution comprised of from about 0 to 98% by weight water-soluble, polar organic compound, about 2 to 100% by weight water, and about 0 to 12% by weight water-soluble salt; wherein the electrically-conductive, pressure-sensitive adhesive contains from about 12% to about 50% by weight non-volatile copolymer matrix, the hydrogen bond donating sites on the copolymer are from about 5% to about 80% neutralized, and the composition is substantially homogeneous and pressure-sensitive adhesive.

Claim 20

The biomedical electrode of claim 15 further comprising a medical tape comprised of a backing and a biocompatible pressure-sensitive adhesive coated on one surface of the backing wherein the conductor adheres to a portion of the medical tape and the remainder of the medical tape extends beyond the perimeter of the conductor.

Claim 23

The method of claim 17 further comprising laminating onto the surface of the conductor opposing the electrically-conductive, pressure-sensitive adhesive a medical tape comprised of a backing and a biocompatible pressure-sensitive adhesive coated on one surface of the backing and cutting the medical tape to a shape and size that provides an apron of medical tape extending beyond the perimeter of the conductor.