Composite membranes useful for the separation of organic compounds of low molecular weight from aqueous inorganic salts containing solutions
US4767645A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1987 |
| Grant date | Aug 30, 1988 |
| Priority date | — |
| Expiry date | Apr 17, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Semipermeable composite membranes suitable for separating organic compounds of low molecular weight from aqueous, inorganic salts containing solutions are provided. These membranes are obtained by PA0 coating one side of a membrane support with an aqueous solution containing dissolved therein an organic, film-forming, hydrophilic polymer, and a cross-linking agent (1) and optionally ionic monomeric compounds to form at least one polymer layer, PA0 contacting the still wet polymer layer(s) interfacially with an organic solution of a cross-linking agent (2), containing at least two functional groups, PA0 drying the resultant product for a time sufficient to form the composite membrane comprising the membrane support and an asymmetrical coating consisting of polymer layer(s) and a thin semipermeable crosslinked film, containing ionic groups resting on the top of said layer and being integrally attached thereto. Optionally the membranes can be further stabilized by treating them with an aqueous solution containing a cross-linking agent (3) capable of reacting with the polymer and/or unreacted groups of the monomeric compound, followed by a curing step. The membranes are suitable to sep…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.