Fluoropolymer dispersion containing no or little low molecular weight fluorinated surfactant
US6861466B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2004 |
| Grant date | Mar 1, 2005 |
| Priority date | — |
| Expiry date | Jan 20, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L71/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
In an aspect of the invention, a fluoropolymer dispersion, preferably a PTFE dispersion, is provided that comprises fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water whereby the dispersion has an amount of solids between 35 and 70% by weight. The dispersion is free of fluorinated surfactant having a molecular weight of less than 1000 g/mol (hereinafter called low molecular weight fluorinated surfactant) or contains the low molecular weight fluorinated surfactant in an amount of not more than 0.05% by weight based on the total weight solids of the dispersion. The dispersion further comprises a non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants and one or more non-fluorinated anionic surfactants. Through the use of a non-fluorinated anionic surfactant, a dispersion is obtained that has a low viscosity at room temperature (20° C.). The dispersion is further free of aromatic group containing non-ionic surfactants and is accordingly environmentally more friendly and can yield coatings that are less susceptible of discoloration. The amount and nature of the non-ionic non-fluorinated surfactant or mixture of no…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.