Stretchable polymer thick film silver conductor for highly permeable substrates

1. An electrical circuit on a wearable garment, the electrical circuit comprising:

(i) a conductor formed from a polymer thick film conductor composition comprising:

(a) 30 to 70 wt % silver flakes;

(b) 20 to 50 wt % first organic medium comprising 10 to 50 wt % thermoplastic urethane resin dissolved in a first organic solvent, wherein the weight percent (wt %) of the thermoplastic urethane resin is based on the total weight of the

(c) organic medium; and

(d) 5 to 20 wt % second organic medium comprising 10 to 50 wt % thermoplastic polyhydroxyether resin dissolved in a second organic solvent wherein the weight percent of the thermoplastic polyhydroxyether resin is based on the total weight of the organic medium;

wherein the ratio of the weight of the first organic medium to the weight of the second organic medium is in the range from 2.3 to 3.7, wherein the weight percent of the silver flakes, the first organic medium and the second organic medium are based on the total weight of the polymer thick film conductor composition; and

(ii) a polyamide-coated woven polyester substrate, wherein the polymer thick film conductor composition is deposited on the polyamide-coated woven polyester substrate and is then dried to form the conductor on the polyamide-coated woven polyester substrate.

2. The electrical circuit of claim 1 , wherein said thermoplastic urethane resin is a linear hydroxyl polyurethane.

3. The electrical circuit of claim 1 , wherein said thermoplastic urethane resin is a polyester-based copolymer.

4. The electrical circuit of claim 1 , wherein said permeable substrate is a woven polyester coated with polyamide.

5. The electrical circuit of claim 1 , wherein said ratio of the weight of the first organic medium to the weight of the second organic medium is about 3:1.

6. A process for making an electrical circuit on a wearable garment, the electrical circuit comprising a conductor formed from a thick film conductor composition, said process comprising the steps of:

(a) providing a polyamide-coated woven polyester substrate;

(b) providing a polymer thick film conductor composition comprising:

(i) 30 to 70 wt % silver flakes;

(ii) 20 to 50 wt % first organic medium comprising 10 to 50 wt % thermoplastic urethane resin dissolved in a first organic solvent, wherein the weight percent (wt %) of the thermoplastic urethane resin is based on the total weight of the organic medium; and

(iii) 5 to 20 wt % second organic medium comprising 10 to 50 wt % thermoplastic polyhydroxyether resin dissolved in a second organic solvent wherein the weight percent of the thermoplastic polyhydroxyether resin is based on the total weight of the organic medium;

wherein the ratio of the weight of the first organic medium to the weight of the second organic medium is in the range from 2.3 to 3.7 and wherein the weight percent of the silver flakes, the first organic medium and the second organic medium are based on the total weight of the polymer thick film conductor composition;

(c) depositing said polymer thick film conductor composition onto said polyamide-coated woven polyester; and

(d) drying the polymer thick film conductor composition that was deposited in step (c) to form the conductor on the polyamide-coated woven polyester substrate.

7. The process of claim 6 , wherein said thermoplastic urethane resin is a linear hydroxyl polyurethane.

8. The process of claim 6 , wherein said thermoplastic urethane resin is a polyester-based copolymer.

9. The process of claim 6 , wherein said permeable substrate is a woven polyester coated with polyamide.

10. The process of claim 6 , wherein said ratio of the weight of the first organic medium to the weight of the second organic medium is about 3:1.