Abstract: A process for producing a propylene block copolymer in the presence of a highly stereospecific olefin polymerization catalyst which comprises producing a crystalline polymer or copolymer of propylene in a first stage and random-copolymerizing propylene and another alpha-olefin in a mole ratio of from 10:90 to 90:10 in the presence of the propylene polymer or copolymer in a second stage; wherein in the random copolymerization, 0.0001 to 0.5 mole, per gram atom of aluminum in the catalyst, of an oxygen-containing compound being gaseous in a standard condition or 0.001 to 1 mole, per gram atom of aluminum in the catalyst, of an active hydrogen-containing compound being liquid or solid in a standard condition is fed into the random-copolymerization reaction system.

Abstract: In a process for producing an olefin polymer which comprises continuously polymerizing an olefin in the presence of a catalyst composed of a transition metal compound component and an organometallic compound component in at least two independent polymerization zones connected in series by a pipeline while feeding the olefin and the catalyst into an upstream zone of polymerization and withdrawing the resulting polymer from a downstream zone of polymerization; the improvement wherein(1) the polymerization in the upstream polymerization zone is carried out in a liquid medium under conditions for slurry polymerization,(2) the solid polymer-containing slurry discharged from the upstream polymerization zone is fed into a liquid medium exchanging zone through an upper feed opening (A) in its upper portion, said liquid medium exchanging zone being provided between the upstream polymerization zone and the downstream polymerization zone and connected to these zones by pipelines, and an additional supply of the liquid m

Abstract: An improved fluidizing apparatus includes a gas distribution plate which is supported by support means located below the level of the gas distribution plate. The support means comprises beam members extending across the interior of the vessel and a number of rods standing upright on the beam members, with the gas distribution plate placed on the uppermost ends of the rods. The support means can also include annular members made integral with the beam members and/or a projection or projections projecting inward from the inner wall surface of the vessel. A number of rods can stand upright on the annular members.