Highly permeable composite reverse osmosis membrane, method of producing the same
US5843351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1996 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Aug 14, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A20/131
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention provides a composite reverse osmosis membrane having a polyamide type skin layer whose average surface roughness is at least 55 nm, and the polyamide type skin layer comprises the reaction product of a compound having amino groups and polyfunctional acid halide compound having acid halide groups. The composite reverse osmosis membrane of this invention is superior in salt rejection and water permeability. A polymer film is formed on a supporting film by contacting a solution containing e.g., m-phenylenediamine with a porous polysulfone supporting film so as to form a layer of the solution on the supporting film, then contacting the film with a solution of trimesic acid chloride and holding the film in a hot air dryer so that a polymer film is formed on the supporting film. The surface of the polyamide type skin layer can also be treated with quaternary ammonium salt and coated with a crosslinked layer of an organic polymer having positively-charged groups. Raw liquid is transmitted from a raw liquid tank to a membrane module for the first stage through a first transmission pump, and the first stage of reverse osmosis treatment is carried out. The composite reverse os…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.