PREPARATION OF POLYPHENYLENE ETHERS, AND AN APPARATUS FOR THIS PURPOSE

Disclosed is a process of preparation of polyphenylene ethers from monohydric phenols, which possess alkyl substituents in the two ortho-positions and, if desired, in the meta-position, but not in the para-position, by an oxidative coupling reaction with oxygen at from 15 to 50.degree.C and under from 1 to 10 bar in the presence of a catalyst complex, of a solvent and, if required, of an activator. In this process,the conversion of the phenols is carried out in two or more reaction zones. Some or all of the solvent, catalyst complex phenols and where relevant, activator are initially added to one of the reaction zones and are circulated in the other reaction zone and about 60-100% of the stoichiometric amount of oxygen required for the oxidative coupling is introduced into the first reaction zone and from 0 to about 40% of the said stoichiometric amount is introduced into the second reaction zone. This process is interesting in that it makes it possible to carry out oxidative coupling of phenols with oxygen in a very economic and reliable manner, with very high space-time yields, formation of only a small amount of by-products, and minimum emissions of gas and volatile components.