| 摘要 |
PURPOSE:To obtain the titled quality polyester inexpensively in good efficiency, by using a thin-film polymerization tank as the last-stage reaction tank in a continuous melt polymerization process and operating this tank in conditions in which a specified relationship between the average residence time and the internal reaction temperature holds. CONSTITUTION:Terephthalic acid (dialkyl ester) and ethylene glycol are converted into a polyester monomer and/or prepolymer in an esterification tank or transesterification tank and then converted into a polymer of an intermediate MW corresponding to an intrinsic viscosity of 0.3-0.7 in the initial and intermediate polymerization tanks. This polymer is polymerized in a thin-film polymerization tank in which the polymer fed from a sparger 15 in the peripheral direction is formed into a film by rotating impellers 14 arranged concentrically in the direction of the periphery of a reaction tank 13 in conditions in which the average resisdence time theta(min) and the internal reaction temperature T( deg.C) can satisfy the relationship (wherein 280<=T) to obtain the titled polyester of an intrinsic viscosity >=0.8 and a carboxyl end group content <=20 equivalent/ T. This polyester is solidified by cooling, comminuted by means of a cutter and used as, e.g., a fiber for clothing and industrial materials.
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