Abstract: The invention relates to a continuous process for the preparation of segmented elastomer polyester copolymers that shows greater flexibility with respect to the types and amounts of product to be produced than the known processes. The flexibility is achieved by splitting up a low-molecular PBT product stream from a continuous PBT process and partly using it as feed for the transesterification reaction with the polyalkyleneoxide glycol yielding soft segments to form a low-molecular segmented polyester copolymer, which is subsequently further condensed in the melt or optionally in the solid phase to form high-molecular segmented polyester copolymers. Even greater flexibility can be obtained by operating several parallel production lines for segmented polyester copolymer. Fluctuations in the types of copolyester product to be produced and the amounts thereof are accommodated predominantly in the polycondensation step of the PBT production.

Abstract: The reactor device comprises a horizontally-disposed housing (1), at one end of which there is disposed an inlet (4) for supply of the medium, and at the other end of which there is an outlet (5) for the reaction products. Within the housing (1) of the reactor device a rotor (1) is rotatably mounted. The rotor (8) has a hollow cylinder (9), which is provided with openings (10) and annular members (12, 13) for moving and transporting the medium. The hollow cylinder (9) is partly immersed in the free-flowing medium, the openings (10) in the hollow cylinder (9) ensuring additional admixture of the medium.

Abstract: A process and an apparatus for the production of high molecular weight linear polyester is proposed, in which a pumpable material is produced in particular terephthalic acid and an alkaline diol which is esterified in a two or multi-stage reactor arrangement and is subsequently condensed in vacuo in at least one vacuum reactor. The waste heat of the esterification reactor arrangement is used for producing the vacuum in the vacuum reactors. The water for condensing the steam is also obtained from the process steam.