Polyetheric copolymers, process for preparing the same compositions containing the same, their molded products, and their use

A polyetheric block copolymer comprising:

• a benzonitrile recurring unit block as represented by the following general formula (III):
• ##STR38## (wherein m is an integer from 10 to 100) and a benzophenone recurring unit block as represented by the following general formula (IV):
• ##STR39## (wherein n is an integer of 80 or smaller) wherein the molar ratio of benzonitrile in said recurring unit (III) to the sum of said benzonitrile in recurring unit (III) and benzophenone in recurring unit (IV), is in the range from 0.15:1 to 0.4:1, and wherein said copolymer has a melt viscosity at 420.degree. C. in the range of 500 to 100,000 poise.

A process for the preparation of powdery polyetheric copolymer having a high bulk density comprising the step of:

• removing an aprotic polar solvent from a final reaction mixture of the aprotic polar solvent with the polyetheric copolymer obtained by reacting the dihalogeno benzonitrile and the 4,4'-dihalogeno benzophenone with 4,4'-biphenol in the presence of an alkali metal compound in an aprotic polar solvent.