ELECTROLYTIC PREPARATION OF QUATERNARY AMMONIUM HYDROXIDE

PURPOSE:To mass-produce a quaternary ammonium hydroxide with low electrolysis voltage, by supplying an aqueous quaternary ammonium salt solution and water to anodic and cathodic chambers, respectively, divided from each other with a composite membrane prepd. by forming a porous metal (oxide) layer as an electrode on the surface of a cation-exchange membrane, and applying a DC. CONSTITUTION:An electrolytic cell divided into anodic and cathodic chambers with a composite membrane in which a porous metal, e.g. Pt or Rh, or metal oxide layer acting as an electrode is formed on one or both surfaces of a cation-exchange membrane is prepared. Then, an aqueous solution containing 10-50wt% a quaternary ammonium salt (e.g. tetramethyl ammonium chloride) represented by formula is supplied to the anodic chamber of said electrolytic cell, while water is supplied to the cathodic chamber. The temp. of a liquid in the electrolytic cell is held below 50 deg.C, and a DC is applied with current density of 1-100A/dm to each of the anode and the cathode to perform electrolytic reaction. Hence, an aqueous quaternary ammonium hydroxide solution is obtained with cocentration of 1-40wt% as a product. Hereon, voltage necessary for the electrolysis is sufficiently 1/2-1/10 as compared with a conventional method, so that the cost of electric power can be remarkably curtailed.