Novel ionic conduction membrane for chlor-alkali industry and preparation method thereof

Abstract

The invention belongs to the technical field of ionic membranes and particularly relates to a novel ionic conduction membrane for chlor-alkali industry. The membrane consists of a perfluorosulfonate ion-exchange resin based membrane, a porous reinforcing material and a surface layer formed by mixing microparticles of fluorine-containing resin and particles of an inorganic compound. The particles of the inorganic compound are selected from one or more of oxides, hydroxides and nitrides of group IV-A, group IV-B, group V-B, iron, cobalt, nickel, chromium, manganese or boron. The microparticles of fluorine-containing resin comprise one or more of microparticles of polytetrafluoroethylene, microparticles of PFA (Polyfluoroalkoxy), microparticles of polyfluorinated ethylene propylene, microparticles of polyfluorinated propyl vinyl ether or microparticles of polyvinylidene fluoride. The ionic conduction membrane for chlor-alkali industry can stably and efficiently treat alkali chloride solutions with wide concentration range and is suitable for operation in a zero polar distance electrolytic bath under a novel electric current density condition, so that the product purity is high. The invention further provides a preparation method of the ionic conduction membrane and the preparation method is simple and reasonable in process and easy for industrialized production.

Description

technical field [0001] The invention belongs to the technical field of ion membranes, and in particular relates to a novel ion conduction membrane used in the chlor-alkali industry 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...

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] Patent US 4502931 mentions that the surface of the ionic membrane is roughened and modified by ion etching, but this method is not easy to implement in a large area, and the anti-foaming ability is not high. The cell voltage is still greater than 3.5V, and the current efficiency is lower than 90%