Patent attributes
The method for producing a propylene-ethylene block copolymer in accordance with the present invention has: a first polymerization process which is performed using two or more polymerization tanks connected in series and in which a solid catalyst or a prepolymerized catalyst containing a solid catalyst, and propylene are continuously supplied to a first polymerization tank; and a second polymerization process in which propylene, ethylene, and polypropylene particles continuously extracted from the last polymerization tank of the first polymerization process are supplied to a polymerization tank to produce a propylene-ethylene block copolymer, wherein the average retention time of the polypropylene particles in each polymerization tank of the first polymerization process is 0.1 to 1.5 h and the sum total of average retention times of polypropylene particles in the polymerization tanks of the first polymerization process is 1.5 to 3.0 h.
