Process for the preparation of aqueous dispersions of fluoropolymers
US6576703B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Apr 8, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/26
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for the preparation of a dispersion based on homopolymers/copolymers of tetrafluoroethylene (TFE), said dispersion having a bimodal or multimodal distribution of the particle diameters, wherein the fraction of small particles is in the range 1.5-35% by weight calculated on the dry product; the ratio between the average diameter of the small particles with respect to the average diameter of the dispersion obtained from the polymerization being in the range 0.02-0.6; said process comprising the following essential steps:(a) preparation of an aqueous microemulsion comprising fluorinated surfactants and (per)fluoropolyether oils (PFPE);(b) feeding of the microemulsion into the polymerization reactor;(c) feeding of at least one fluorinated surfactant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.