Manufacture of polyethers from bis-(4-hydroxyphenyl)-sulfone and bis-(4-chlorophenyl)-sulfone in N-methylpyrrolidone using an alkali metal carbonate as catalysts

Claim 1

A process for the manufacture of polyethers by reacting substantially equivalent amounts of bis-(4-hydroxyphenyl)-sulfone with bis-(4-chlorophenyl)-sulfone in the solvent N-methylpyrrolidone in the presence of an anhydrous alkali metal carbonate, wherein (a) in a first stage of the reaction a solution of one mole of bis-(4-hydroxyphenyl)-sulfone is reacted with about one mole of bis-(4-chlorophenyl)-sulfone in the presence of from 1 to 2 moles of an anhydrous alkali metal carbonate and in the presence of a compound which forms an azeotrope with water, at an average temperature of from 100° C. to 170° C., until at least 90% of the amount of water which can theoretically be formed has been removed, (b) in a second stage of the reaction, further amounts of the compound which forms an azeotrope are added to the reaction mixture while raising the temperature to an average temperature of from 150° C. to 230° C., and at the same time the azeotropic mixture formed is distilled off, until the reaction mixture is completely anhydrous, (c) in a third stage of the reaction, the reaction mixture is polycondensed at an average temperature of from 150° C. to 230° C. until its reduced viscosity is from 0.4 to 1.5 and the polymerization is then stopped by adding methyl chloride and (d) the polyether formed is separated from the solvents and inorganic constituents.