Highly permeable composite reverse osmosis membrane
US6171497A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2323/30
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A module that can be practically used at a pressure of about 3 kgf/cm.sup.2 is obtained by treating a polyamide based reverse osmosis membrane with an oxidizing agent. A composite reverse osmosis membrane comprises a thin film which is a polyamide based skin layer obtained by polycondensation of a compound having two or more reactive amino groups and a polyfunctional acid halide compound having two or more reactive acid halide groups, and a microporous support for supporting the thin film. The polyamide based skin layer formed on the surface of the membrane has a mean roughness of 50 nm or more. The composite reverse osmosis membrane is treated with an oxidizing agent. A salt rejection of 99% or more and a flux of 1.5 m.sup.3 /m.sup.2.multidot.day or more are obtained when evaluated by using a solution having pH 6.5 containing 500 ppm of sodium chloride at an operating pressure of 7.5 kgf/cm.sup.2 and a temperature of 25.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.