Abstract
The invention is a method for sizing polytetrafluoroethylene fabrics comprising: (a) forming a sizing composition of a perfluorinated polymer containing sites convertible to ion exchange groups and a treating agent having: a boiling point less than about 110 DEG C.; a density of from about 1.55 to about 2.2; and a solubility parameter of from greater than about 7.1 to about 8.2 hildebrands; (b) contacting the sizing composition with the fibers of a polytetrafluoroethylene fabric; and (c) removing the treating agent from the sizing composition. Particularly preferred as a treating agent is a compound represented by the general formula: XCF2-CYZX' wherein: X is selected from the group consisting of F, Cl, Br, and I; X' is selected from the group consisting of Cl, Br, and I; Y and Z are independently selected from the group consisting of H, F, Cl, Br, I and R'; R' is selected from the group of perflluoroalkyl radicals and chloroperfluoroalkyl radicals having from 1 to 6 carbon atoms. The most preferred treating agent is 1,2-dibromotetrafluoroethane.
Front-page drawing from US4784900A
Front-page drawing from US4784900A
| Original language | English |
|---|---|
| Patent number | US4784900A |
| IPC | B01D67/00 |
| Priority date | 31/05/85 |
| Filing date | 9/05/86 |
| Publication status | Published - 15 Nov 1988 |
| Externally published | Yes |