Composite reverse osmosis membrane and process for preparing the same
US6723422B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1999 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Dec 30, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249992
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A composite reverse osmosis membrane is described, which includes a polyamide skin layer on a porous support, with a contact angle between the polyamide skin layer surface and water of 45° or less. The composite reverse osmosis membrane has a high salt rejection and also a high water permeability. This composite reverse osmosis membrane is produced by forming a polyamide skin layer on a porous support having the steps of: forming a layer on the porous support by coating a solution A including one or more compounds having at least two reactive amino groups; contacting the layer with a solution B comprising one or more polyfunctional acid halide compounds; and subsequently, contacting the layer with a solution C comprising the polyfunctional acid halide compound of a higher concentration than the solution C. The concentration of the polyfunctional acid halide compound in the solution C is preferably at least 1.2 times of the solution B.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.