Process for removing fluorosurfactant from aqueous fluoropolymer dispersions and reducing scum formation
US7619018B2 · kind B2 · utility
1Cited by
14References
8Claims
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Key dates
| Filing date | Dec 2, 2005 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Aug 5, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F214/18
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for reducing fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion containing ferric ions by contacting the fluoropolymer dispersion with strong base anion exchange resin to reduce fluorosurfactant content to a predetermined level, the anion exchange resin being in the hydroxide form, separating the dispersion from the anion exchange resin, and adding an effective amount of chelating agent having an equilibrium constant when complexed with iron of at least 1018 prior to the contacting with the ion exchange resin for complexing ferric ions to prevent scum formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.