PRODUCTION OF ETHYLENE/PROPYLENE ELASTOMERIC COPOLYMER

PURPOSE:To obtain an elastomeric copolymer having excellent resin properties and suited as a thermoplastic rubber by copolymerizing a propylene/ethylene monomer mixture containing a liquid monomer in the presence of a specified catalyst containing Ti, Al and an organic acid ester. CONSTITUTION:The purpose copolymer is obtained by copolymerizing a monomer mixture of propylene with ethylene containing at least one liquid monomer in the absence of any inert solvent in the presence of a catalyst comprising a mixture of a solid titanium catalyst component obtained by copulverizing a magnesium halide with an organic acid ester and a titanium halide compound and having a specific surface area of 30-80m /g and a molar ratio of the ester to the magnesium halide of 0.005-0.165, an organoaluminum compound and an organic acid ester. As the organic acid ester used, ethyl benzoate is particularly desirable.