Process for preparing modified PTFE
US6262209A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jan 22, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F214/262
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Method for preparing modified PTFE by suspension, wherein as comonomers perfluoroalkylvinylethers in which the alkyl has from 1 to 5 carbon atoms, and/or a perfluorodioxole are used, characterized by the following conditions: PA1 a part of the comonomer, from 15 to 90% by weight of the total amount is to be fed at the beginning of the reaction; the remaining part of the comonomer is to be distributed during the reaction so as to obtain a constant speed of the comonomer incorporation in the polymer chain; PA1 a perfluorinated surfactant and a buffering salt are used; PA1 a persulphate with a reducing agent is used as initiator in such a ratio as to generate a part of the radicals from the redox reaction and another one from the persulphate thermal decomposition; PA1 one operates with a polymerization pressure from 15 to 30 bar.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.