Process for producing microporous powders and membranes
First Claim
1. A process for producing microporous powders or shaped articles, comprising preparing a solution of at least one polymer selected from the group consisting of polyvinylidene fluoride, polyphenylene sulfide, polysulfone, polyacrylonitrile, ethylene/vinyl alcohol copolymer, ethylene/chlorotrifluoroethylene copolymer, polyether-sulfone, polyether-imide, polymethyl methacrylate, polycarbonate, cellulose triacetate and copolymers thereof in a solvent mixture containing e-caprolactam as the essential dissolving constituent, forming said solution, and triggering phase separation thermally or by a non-solvent.
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Accused Products
Abstract
A process produces microporous powders or shaped articles, in particular membranes in the form of flat films, tubular films or hollow fibers, which may be used for controlled release of an active compound, for dialysis, gas separation, ultrafiltration or microfiltration, from polyvinylidene fluoride and/or polyphenylene sulfide and/or polysulfone and/or polyacrylonitrile and/or ethylene/vinyl alcohol copolymer and/or ethylene/chlorotrifluoroethylene copolymer and/or polyethersulfone and/or polyether-imide and/or polymethyl methacrylate and/or polycarbonate and/or cellulose triacetate. The process utilizes phase separation by means of thermally induced triggering or triggering induced by a non-solvent of a solution of the polymer in a mixture containing ε-caprolactam as the essential dissolving constituent. The solution may be formed before the phase separation is triggered.
212 Citations
11 Claims
- 1. A process for producing microporous powders or shaped articles, comprising preparing a solution of at least one polymer selected from the group consisting of polyvinylidene fluoride, polyphenylene sulfide, polysulfone, polyacrylonitrile, ethylene/vinyl alcohol copolymer, ethylene/chlorotrifluoroethylene copolymer, polyether-sulfone, polyether-imide, polymethyl methacrylate, polycarbonate, cellulose triacetate and copolymers thereof in a solvent mixture containing e-caprolactam as the essential dissolving constituent, forming said solution, and triggering phase separation thermally or by a non-solvent.
Specification