PURPOSE: To produce a particulate thermoplastic olefin elastomer of excellent properties economically and stably, by polymerizing olefins by using a specified catalyst system by a vapor phase polymerization process in two stages.
CONSTITUTION: Isotactic polypropylene is obtained (step 1) by polymerizing propylene in liquefied propylene or a vapor phase by using a catalyst system comprising a solid catalyst component prepared by impregnating a porous organic carrier with a catalyst component containing Ti, Mg, Cl and an ester compound, an organoaluminum compound and an electron donating compound. A random copolymer of ethylene with an α-olefin is formed in a vapor phase (step 2) so that the ethylene content of the copolymer formed in this step may be 15W90mol.%, that the intrinsic viscosity in tetralin at 185°C may be 0.8W15, and that the copolymer formed in the step 2 may amount to 60W97wt.% based on the total polymer. In this way, a particulate thermoplastic olefin elastomer of excellent properties can be produced economically and stably.
EBARA TAKESHI
TAKARA HIROMASA
KAWAI SEIJI
