The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 20, 2004
Filed:
Dec. 30, 1999
Nitto Denko Corporation, Osaka, JP;
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.