Stretchable polymer thick film silver conductor for highly permeable substrates

• US 9,253,883 B2
• Filed: 11/18/2013
• Issued: 02/02/2016
• Est. Priority Date: 11/18/2013
• Status: Active Grant

• Current Assignee: Du Pont China Limited (DuPont de Nemours, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Dorfman, Jay Robert, Critzer, Mark Steven
• Primary Examiner(s): KOPEC, MARK T
• Application Number:
  US14/082,600
• Publication Number:
  US 20150137048A1
• Time in Patent Office: 806 Days
• US Class Current: 1/1
• CPC Class Codes: B05D 5/12 to obtain a coating with specific electrical properties
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C09D 171/00 Coating compositions based on polyethers obtained by reactions forming an ether link in the main chain based on polyacetals C09D159/00; based on epoxy resins C09D163/00; based on polythioether-ethers C09D181/02; based on polyethersulfones C09D181/06; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 175/00 Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 13/30 Drying; Impregnating H01B13/32 takes precedence
• CPC Class Codes: H05K 1/038 Textiles used as reinforcing materials for organic insulating substrates H05K1/0366

Abstract

This invention is directed to a polymer thick film conductor composition. The polymer thick film (PTF) conductor composition may be used in applications where significant stretching is required, particularly on highly permeable substrates. A particular type of substrate which is suitable is a woven polyester coated with polyamide. An electrical circuit containing a conductor formed from the composition and a process to make such a circuit are provided.

Claims

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.