Copolymers of vinylidene fluoride and hexafluoropropylene and process for preparing the same
US6187885A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 3, 1995 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Jan 3, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F214/22
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Melt processable copolymers of vinylidene fluoride and hexafluoropropylene, containing from about 1% to about 20% hexafluoropropylene by weight, are prepared by emulsion polymerization of vinylidene fluoride and hexafluoropropylene in a stirred aqueous reaction medium. The reaction medium is formed by charging to a heated reactor, water, vinylidene fluoride, an initiator to start the polymerization, and a water-soluble surfactant capable of emulsifying both the initiator and the reaction mass during polymerization. Additional amounts of vinylidene fluoride and initiator are fed to the reaction medium to continue polymerization of the vinylidene fluoride monomer until from about 50% to about 90% of the total weight of the vinylidene fluoride monomer utilized in the process has been added to the reaction medium. There is then added to the reaction medium (i) from about 1% to about 20% hexafluoropropylene by weight, based upon the combined weight of the hexafluoropropylene and the total weight of the vinylidene fluoride utilized in the process, and (ii) the balance of the vinylidene fluoride utilized in the process. The resulting vinylidene fluoride/hexafluoropropylene copolymers are …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.