Aqueous dispersion of polytetrafluoroethylene and process for its production
US7514483B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2005 |
| Grant date | Apr 7, 2009 |
| Priority date | — |
| Expiry date | Nov 26, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/285
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An aqueous dispersion of polytetrafluoroethylene (PTFE) comprising from 55 to 70 mass % of PTFE fine particles having an average particle diameter of from 0.1 to 0.5 μm, from 0.0001 to 0.02 mass %, based on PTFE, of a specific C8 fluorine-containing carboxylic acid salt (APFO) such as ammonium perfluorooctanoate, from 1 to 20 mass %, based on PTFE, of a specific nonionic surfactant and from 0.01 to 0.3 mass %, based on PTFE, of a specific C5-7 fluorine-containing carboxylic acid salt such as ammonium perfluorohexanoate. The aqueous dispersion of PTFE has excellent properties which can form crack-resistant coatings which do not undergo coloration during baking or form problematic ionic impurities by improving the friction stability of aqueous PTFE dispersions even at APFO concentrations without viscosity increase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.