Expanded porous polytetrafluoroethylene film having elastic recovery property in thickness-wise direction of the film, production process thereof, and use of the porous film
US7976751B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2009 |
| Grant date | Jul 12, 2011 |
| Priority date | — |
| Expiry date | Jun 6, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249953
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An expanded porous polytetrafluoroethylene film having residual strain of at most 11.0% as measured after a load required to indent a rod, which is in a columnar form that its outer diameter is at least 2 mm and at least 1.9 times as much as the thickness of the film, and has a smooth plane perpendicular to its axis at a free end surface thereof and a modulus of longitudinal elasticity of at least 1.0×104 kgf/mm2, up to 20% of the film thickness at a strain rate of 100%/min from the free end surface is applied repeatedly 20 times, and a production process of the porous film, in which a step of compressing an expanded porous polytetrafluoroethylene film having a high draw ratio is provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.