PROCESS FOR THE POLYMERIZATION OF PHENOLS AT LOW OXYGEN FLOWRATES

摘要

The need for indirect cooling and for pure oxygen are decreased without offsetting disadvantages in the batch manufacture of polyphenylene ether resins by the catalyzed oxidation of hindered phenols, by introducing oxygen into the catalyst-phenol-solvent solution at such rate that about 1/4 to 3/4 of said phenol is in prepolymer state when about 1/3 to 2/3 of the charge of phenol has been added to the reaction mixture. Lengthening of the time over which the phenol is added decreases the proportion of the diphenoquinone byproduct which is formed.