Production of asymmetrical microporous membranes by double irradiation and asymmetrical membranes
US4832997A · kind A · utility
26Cited by
6References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1987 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Nov 20, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249978
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Process for the production of asymmetrical microporous membranes by double irradiation. A membrane (5) is exposed to two irradiations, whereof one has an inadequate energy level to pass through the same, whereas the other passes through membrane (5). The irradiations produce molecular defects, which are attacked or etched in preferred manner by certain chemical agents. Thus, two networks of pores are obtained, one network being of large diameter and of a non-issuing nature (26), the other being smaller (27, 28, 29) and which issue on to the two surfaces (31, 32) of membrane (5). Application to filtration and sterilization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.