Water-vapor-permeable, waterproof, highly elastic films
US4692369A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 9, 1985 |
| Grant date | Sep 8, 1987 |
| Priority date | — |
| Expiry date | Dec 9, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/413
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A water-vapor-permeable, waterproof, highly elastic film of expanded, porous, unsintered polytetrafluoroethylene having impregnated within the pores of the porous film, on both sides thereof, a water-vapor-permeable resin, for example, an elastomer containing urethane bonds and a hydrophilic group(s) in its molecular structure. The film of this invention is useful in clothing, tents, and various applications where water vapor transmission characteristics and waterproofness are simultaneously desired. The film has elongation percentage in at least one direction exceeding 40% and durability in repeated stretching to 80% of its elongation percentage of more than 200,000 cycles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.