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:
Nov. 26, 2002
Filed:
Oct. 28, 1999
Jong Ok Won, Seoul, KR;
Yong Soo Kang, Nowon-ku, KR;
Hyun Chae Park, Seoul, KR;
Un Young Kim, Seoul, KR;
Seong Hyun Yoo, Seoul, KR;
Korea Institute of Science and Technology, Seoul, KR;
Abstract
An asymmetric support membrane can be prepared by using a phase separation method. The method includes immersing a polymer solvent solution into water. The polymer solution is made by dissolving 15 to 35% by weight of the polymer into a solvent that lets the polymer solution become a gel at a temperature of 0 to 50° C. The solution is then allowed to gel and brought into a final membrane form in water for phase separation and formation of the asymmetric support membrane. The polymer may be poly(vinyl chloride), polyethersulfone, polyetherimide and polyamic(methylester). The solvent is &ggr;-butyrolactone alone as a major solvent or is a mixed solvent with N-methyl-2-pyrrolidone as a cosolvent. The asymmetric support membrane is a porous support membrane of a sponge form having open pores that are connected to one another with a narrow pore size distribution. Thus, the asymmetric support membrane has an improved permeance and mechanical strength. Further, because it has a narrow pore size distribution, a coating process can be optimized with a material having high selectivity. Therefore, the composite membranes having improved selectivity can be easily produced by the present invention.