Aqueous polytetrafluoroethylene emulsion, polytetrafluoroethylene fine powder and porous material obtained therefrom
US7851573B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2008 |
| Grant date | Dec 14, 2010 |
| Priority date | — |
| Expiry date | Apr 17, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249962
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
To provide an aqueous polytetrafluoroethylene (PTFE) emulsion which does not substantially contain ammonium perfluorooctanoate, and which is obtained by emulsion polymerization. Further, to provide a PTFE fine powder which is obtained from the aqueous PTFE emulsion and is excellent in a paste extrusion processability, and a porous material. An aqueous polytetrafluoroethylene emulsion obtained by carrying out emulsion polymerization of tetrafluoroethylene alone or together with another copolymerizable monomer in an aqueous medium, wherein a fluorinated emulsifier of the formula (1): CF2CF2(O)mCF2CF2OCF2COOA wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4, and m is an integer of 0 or i, is used in an amount of from 1,500 to 20,000 ppm, based on the final yield of polytetrafluoroethylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.