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:
Jan. 09, 2001
Filed:
Jan. 21, 1997
Nitto Denko Corporation, Osaka, JP;
Abstract
A module that can be practically used at a pressure of about 3 kgf/cm,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,/m,·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,and a temperature of 25° C.