Preparation of conductive polyurethanes using a conductive quasi-solution

• US 5,898,057 A
• Filed: 05/27/1997
• Issued: 04/27/1999
• Est. Priority Date: 05/25/1995
• Status: Expired due to Term

• Current Assignee: Fleet National Bank (Bank of America Corp.)
• Original Assignee: Mearthane Products Corporation
• Inventors: Chiang, Albert C., Roderick, John A.
• Primary Examiner(s): Truong, Duc
• Application Number:
  US08/863,212
• Time in Patent Office: 700 Days
• Field of Search: 528/71, 528/56, 528/59, 528/61, 528/65, 528/85, 524/589, 524/590, 521/65, 521/67, 521/134, 521/137, 521/155, 521/159, 521/911, 264/457, 264/46.8
• US Class Current: 528/71
• CPC Class Codes: C08K 5/098 Metal salts of carboxylic acids
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: Y10S 521/911 Surfactant for other than polyurethane cellular product

Abstract

A conductive quasi-solution useful for making a homogeneously conductive single-phase polyurethane, comprising a transition metal salt, a carrier solution, and a dispersing agent, wherein said conductive quasi-solution has a transition metal salt concentration between 10 and 30% by weight, and methods of making thermoset and thermoplastic polyurethane polymers therewith.

Claims

1. A method of making a homogeneously conductive single-phase polyurethane, comprising

mixing, with heating, a combination containing between 10% and 30% by weight of a transition metal salt, a dispersing agent, and a solvent comprising a flame retardant and/or polyol to provide a conductive quasi-solution in which said transition metal salt is partially dissolved in said solvent, and

combining said conductive quasi-solution with a polyurethane precursor and a diisocyante to provide a homogeneously conductive single-phase polyurethane containing between 0.02% and 1% of said transition metal salt by weight, wherein at least part of the combining involves reaction injection molding.

2. A method of claim 1, wherein said transition metal salt comprises a transition metal selected from Cu (II), Fe (III), Ni (II), Zn (II), and Co (II), and a counter-anion selected from acetate, tartrate, lactate, phosphate, oxalate, fluoride, chloride, bromide, iodide, thiocyanate, and cyanide.

3. A method of claim 2, wherein said transition metal salt comprises Fe (III) or Cu (II).

4. A method of claim 2, wherein said transition metal is Cu (II) or Fe (III), and said counter-anions are independently selected from acetate, thiocyanate, chloride, or bromide.

5. A method of claim 1, wherein there are at least two transition metal salts in said conductive quasi-solution.

6. A method of claim 5, wherein said transition metal salts comprise Fe (III) and Cu (II).

7. A method of claim 1, wherein said solvent comprises a flame retardant comprising a phosphate haloalkyl ester or a diphosphate haloalkyl ester.

8. A method of claim 1, wherein said dispersing agent comprises a non-ionic surfactant.

9. A method of claim 1, wherein said concentration of said dispersing agent in said conductive quasi-solution is between 0.5% and 5% by weight.

10. A method of claim 1, wherein the product produced as a result of said mixing is a thermoset polyurethane.

11. The method of claim 1, wherein said transition metal salt comprises copper chloride.

12. The method of claim 1, wherein said combining step includes

combining said quasi-solution with a polyurethane precursor to provide a conductive polyurethane precursor, and

combining a first stream comprising said conductive polyurethane precursor and a second stream comprising said diisocyante in a reaction injection molding process to provide the homogeneously conductive single-phase polyurethane.