Method for preparing fluroxene by vertical-tube type catalytic reaction

Abstract

The invention discloses a preparation method of fluorine-containing vinyl ether. The method comprises the following steps of: uniformly mixing a perfluoro-linear chain or branched chain acyl fluoride compound, trifluoroethylene sulfuric ester and anhydrous hydrogen fluoride liquid in the mole ratio of 1:1:(1-20); passing from bottom to top through a vertical-tube type reactor which is filled with a catalyst; finishing addition reaction in a short time under the action of the high specific surface area catalyst inside the reactor; and setting apart a reaction liquid product from the upper part of the vertical-tube type reactor to form a product with a general formula in formula (I). In the invention, a functional fluorine-containing monomer can be prepared continuously and efficiently with no adoption of high temperature pyrolysis path, easily operated reaction equipment, conveniently controlled reaction temperature and no use of any organic solvent, and a high-purity monomer can be obtained through simple rectification. The reaction is carried out continuously inside the reactor and satisfies industrialization requirements. CF2=CF-O-Rf (I).

Description

technical field [0001] The invention belongs to the field of fluorine-containing fine chemicals, and relates to a preparation method of a class of fluoroalkenes, which are widely used in the synthesis of fluororesins with proton exchange functions, and membrane products prepared from such fluororesins are used in the chlor-alkali industry In the electrolytic cell composite membrane diaphragm, it plays a dual role of transporting protons and preventing the reverse migration of hydroxyl radicals from the cathode chamber to the anode chamber. Background technique [0002] Since the ionic membrane electrolysis method was applied in the chlor-alkali industry in the 1970s, this technology has become the development direction of the technical transformation of old factories in the chlor-alkali industry and the development of new electrolysis devices. The use of fluorine-containing ion exchange membranes in electrolyzers is a known technology. Such ionic membranes have bonded anion...

AI Technical Summary

Problems solved by technology

Practice has proved that fluorine-containing ion-exchange membranes containing ion-exchange groups, especially sulfonic acid groups and carboxylic acid groups, are more suitable for use as composite ion-exchange membranes for chlor-alkali electrolyzers due to their resistance to chemical degradation. The exchange membrane of the fluorine-containing carboxylic acid layer mainly prevents the reverse migration of hydroxyl anions into the anode chamber. Once the reverse migration of hydroxyl anions enters the anode chamber, the current efficiency of chlorine gas and caustic soda will be greatly reduced.

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