Patent ID: 8759458

Claim:
A process for the production of polyarylene ether block copolymers comprising (a) the reaction of components (A1) composed of at least one aromatic dihydroxy compound and (A2) composed of at least one 4,4′-dihalodiphenyl sulfone to form a reaction mixture comprising a polybiphenyl sulfone polymer, where component (A1) comprises at least 80% by weight of 4,4′-dihydroxybiphenyl and the reaction according to step (a) is carried out with a molar excess of component (A1), and then (b) reaction of the reaction mixture of step (a) with components (B1) composed of at least one aromatic dihydroxy compound and (B2) composed of at least one aromatic dihalogen compound, where the reaction of the starting compounds (A1) and (A2) takes place in the presence of anhydrous alkali metal carbonate wherein the molar ratio of component (A1) to (A2) in step (a) is from 1.005:1 to 1.2:1, and wherein the aromatic dihalogen compound (B2) is selected from dihalodiphenyl sulfones.