Method for producing modified polytetrafluoroethylene, method for producing modified polytetrafluoroethylene powder, and method for producing stretched porous material
US11780943B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 2020 |
| Grant date | Oct 10, 2023 |
| Priority date | — |
| Expiry date | Jun 6, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2327/22
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.