Porous polymeric films
US4386129A · kind A · utility
43Cited by
5References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1981 |
| Grant date | May 31, 1983 |
| Priority date | — |
| Expiry date | Mar 31, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to porous films having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns and the method for preparing these films. More particularly this invention relates to a porous film having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns formed from a resinous polymer of propylene and the process for forming the film which comprises the steps of (a) forming a film containing beta-spherulites and (b) selectively extracting the beta-spherulites.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.