Asymmetric porous polyamide membranes
US5006247A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1989 |
| Grant date | Apr 9, 1991 |
| Priority date | — |
| Expiry date | Aug 15, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D69/02
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Asymmatric, porous polyamide membranes permeable to fluid flow comprising: PA1 (A) a porous skin layer, and PA1 (B) adjacent to the skin layer, an integral, porous support layer having at least one region comprising a network of substantially parallel, hollow tube-like structures, each of the tube-like structures being oriented such that the longitudinal dimension of each tube-like structure is essentially perpendicular to the skin layer; PA1 wherein PA1 the skin layer is relatively thin and dense compared to the support layer, PA1 the pore diameters in the skin layer are relatively small compared to the diameters of the tube-like structures in the support layer, PA1 in membrances having support layers with more than one region, the cross-sectional area of the tube-like structures is larger in regions located farther from the skin layer, and PA1 the polyamide is an aliphatic polyamide having a glass transition temperature of less than 200.degree. C., and method of making the same. These membranes are useful in ultrafiltration and microfiltration processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.