Polyanilines and their manufacture
US5837806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1996 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | Feb 22, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01B1/128
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A polyaniline is characterized by a nuclear magnetic resonance spectrum in its leuco form showing only two .sup.13 C peaks, indicating the substantal absence of chain branching, and preferably by a molecular weight (M.sub.p) above 90,000 and up to about 170,000 (more especially 100-140,000). Oriented films of such polyanilines in the protonated emeraldine oxidation state have electrical conductivities up to at least around 500 S/cm. They may be made by oxidizing aniline in aqueous solution with a persulfate under the combination of conditions PA1 that the acidity of the solution throughout the reaction is such that if its temperature is adjusted to 20.degree. C. it will have a pH in the range from about -0.2 to +3.0; PA1 that the temperature of the solution is in the range from -5.degree. to about -40.degree. C.; PA1 that the solution contains at least sufficient inert ionic solute to maintain it in the liquid state; and PA1 that the persulfate is added to the solution always at a rate corresponding to a total addition time of at least six hours (but preferably not over 36 hours) and in a molar ratio to the aniline in the range from 1.1:1 to 1.4:1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.