Highly asymmetric ultrafiltration membranes
US5958989A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Jul 8, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249989
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention relates to highly asymmetric polymer membranes for ultrafiltration (UF), and to a simplified method of their manufacture. Disclosed herein are UF membranes with a high degree of asymmetry between the size of pores at the skin face of the membrane and the size of pores at the opposite face of the membrane. Asymmetry ratios of these membranes range from about 20 to about 1000. The porous support layer between the skin face and the opposite face is reticular and is substantially free of macrovoids. These membranes thus have higher flow rates than prior UF membranes. The membranes are cast from polymer dope mixes that are either homogeneous solutions or stable colloidal dispersions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.