Chemical oxidative preparation of conductive polymers
US6334966B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 2000 |
| Grant date | Jan 1, 2002 |
| Priority date | — |
| Expiry date | Nov 6, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/13
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An intrinsically conductive polymer is prepared with a chemical oxidative process. The polymer is prepared by first dipping or coating a substrate with an Fe(III)-containing oxidizer solution and drying. The substrate is then dipped or coated with a monomer, such as 3,4-ethylenedioxythiophene solution, and reacted to form the conductive polymer. The monomer is dissolved in a solvent in which it has a high solubility but in which the Fe(III)-containing oxidizer has low solubility. This minimizes cross-contamination of the monomer and oxidizer dipping solutions thereby making this process suitable for high volume production. Dissolving the monomer in a solvent allows control over the stoichiometric ratio of monomer to oxidizer and prevents an excess of monomer thereby facilitating the removal of any unreacted monomer by water. The substrate is then dipped in an aqueous solution of para-toluenesulfonic acid to facilitate the removal of Fe(II) byproducts by enhancing their solubility in water and then the substrate may be washed with an aqueous solution or pure water. The process produces low ESR and low leakage valve metal capacitors with conductive polymer cathodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.