APPARATUS AND PROCESS FOR PRODUCING AN ION-PERMEABLE WEB-REINFORCED SEPARATOR AND SEPARATOR OBTAINABLE THEREWITH

摘要

An apparatus for producing an ion-permeable web-reinforced separator comprising a duplex type impregnating apparatus comprising two slots each with substantially vertical upper and lower slot faces for providing premetered substantially identical quantities of a dope simultaneously to either side of an elongated porous web, a transport means providing for substantially vertical downwards transport of said elongated porous web through said duplex impregnating apparatus and subsequent phase inversion, coagulation and washing stations, said phase inversion station providing for phase inversion of said dope and said coagulation station providing for coagulation and washing of solvent from the resulting phase-inverted dope, wherein there is an air gap between said duplex impregnating apparatus and said phase inversion station and wherein the distance between the lower faces of each impregnating apparatus is greater than the distances between the upper faces of each impregnating apparatus; a process comprising the steps of : (i) providing an elongated porous web, said elongated porous web comprising two outermost surfaces; (ii) transporting said elongated porous web downwards between two impregnating heads comprising two slots each with substantially vertical upper and lower slot faces substantially parallel to said elongated porous web providing simultaneously to both surfaces of said elongated porous web metered substantially identical quantities of a dope, comprising at least one membrane polymer and at least one solvent therefor; (iii) thereby impregnating said elongated porous web completely with said dope and providing substantially equally thick dope layers on each surface of said outermost surfaces of said elongated porous web with a thickness independent of the gap between one of said lower slot faces and the surface of said elongated porous web nearest thereto; (iv) subjecting said dope associated with said elongated porous web to symmetric phase inversion with at least one non-solvent thereby forming a membrane, and (v) removing residues of said at least one solvent for said at least one membrane polymer from said membrane thereby producing an ion-permeable web-reinforced separator, wherein said dope is shear- thinning and steps (iv) and (v) are optionally performed simultaneously; and the separator obtainable therewith.