Ion-conducting membrane and preparation method thereof

Abstract

The invention belongs to the technical field of ion membranes and specifically relates to an ion-conducting membrane and a preparation method thereof. The ion-conducting membrane comprises a perfluorinated ion-exchange resin-based membrane, a porous reinforced material and a perfluorinated sulfonic acid resin micro-particle surface layer. The perfluorinated ion-exchange resin-based membrane comprises a resin layer which is mainly composed of perfluorinated sulfonic acid resin and another resin layer which is mainly composed of perfluorinated carboxylic acid resin. The surface layer of the ion-conducting membrane provided by the invention has good compatibility and adhesion, so that the good degassing effect throughout the whole life of the ion-conducting membrane can be ensured. When used in the chlor-alkali industry, the ion-conducting membrane is capable of treating an alkali metal chloride solution in a wide concentration range stably and efficiently; and the ion-conducting membrane is suitable for operation in a zero-polar distance electrolyzer under high current density condition and has very excellent product purity index. The invention further provides the preparation method thereof, the process is simple and reasonable and the industrial production is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of ion membranes, and in particular relates to an ion conduction membrane and a preparation method thereof. Background technique [0002] In recent years, in the production of chlor-alkali by ion-exchange membrane method, in order to realize electrolysis under the conditions of high current density, low cell voltage and high concentration of lye, in order to achieve the purpose of increasing productivity and reducing power consumption, the key is to shorten the ion-exchange membrane The distance between the electrode and the electrode can be reduced to reduce the cell voltage, so that the narrow pole distance ion membrane electrolysis process can be practical. With the continuous advancement of technology, the zero-electrode distance electrolyzer has been widely used, but when the distance between the electrodes is reduced to less than 2mm, the hydrogen bubbles attached to the membrane surface are difficult ...

AI Technical Summary

Problems solved by technology

The hydrophilic coating modification process needs to be mixed with inorganic components and special binders, and then covered on the surface of the ion membrane by electrolytic deposition, particle embedding, etc. Patents CA2446448 and CA2444585 have introduced the coating process in detail ; Although the effect of this modification method is remarkable, the process is relatively complicated

In addition, because the ionic membrane will experience continuous scouring and turbulence caused by the lye flow during the electrolysis operation, the hydrophilic coating attached to the surface of the ionic membrane will gradually fall off, and the anti-foaming function will gradually decrease to ineffective.

[0004] The patent US4502931 mentions that the surface of the ionic membrane is roughened by ion etching, but this method is not easy to implement in a large area, and the anti-foaming ability is not high. When the distance between the electrodes is reduced to a certain extent, the groove voltage is still greater than 3.5V, and the current efficiency is less than 90%