Process for producing porous polytetrafluoroethylene film
US5217666A · kind A · utility
29Cited by
6References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 28, 1992 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | May 28, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2327/18
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A porous PTFE film having a thin thickness and good permeability is produced by coating an emulsion of polytetrafluoroethylene on a substrate surface, in particular, a porous polytetrafluoroethylene substrate which has not been heated at a melting point of unsintered polytetrafluoroethylene or higher, heating the coated substrate at a temperature not lower than a melting point of sintered polytetrafluoroethylene to semi-sinter polytetrafluoroethylene, optionally removing the semi-sintered polytetrafluoroethylene film from the substrate, and then stretching the semi-sintered film at least in one direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.