PRODUCTION OF BLOCK COPOLYMER

PURPOSE:To produce a block copolymer inexpensively, by withdrawing a slurry- form polyolefin produced in the polymerization step, separating solid polyolefin by evaporation and copolymerizing this with a different olefin. CONSTITUTION:A slurry-form polyolefin obtained by polymerization in a polymerization tank 1 is fed into a flashing tank 10 via a concentrator 9, the unreacted liquid olefin separated in the concentrator 9 is recirculated into the polymerization tank 1. The solid polyolefin separated from the unreacted olefin by evaporation in the flashing tank 10 is converted into a block copolymer in a vapor-phase polymerization tank 25. Here, 27, 28 and 29 represent olefins and water, respectively. The evaporated olefin vapor is scrubbed with a liquid olefin 16 in a wet scrubber 14 and then the vaporous olefin is separated in a tank 17 and recirculated into the polymerization tank 1. A portion of the scrubbed olefin vapor is heated in a heat exchanger 12 and fed into the flashing tank 10, and the rest is liquefied in a condenser 20, and the condensed liquid is separated in a separator 22 and a portion is recirculated into the wet scrubber 14, and the rest is recirculated into the polymerization tank 1, and transferred into a recovery process through a pipe 24.