Patent ID: 8252888

Claim:
A method for the continuous production of high-molecular polyesters by at least one of esterification of dicarboxylic acids and transesterification of dicarboxylic acid esters with diols in the presence of catalysts with formation of a prepolymer in a tower reactor for the production of a prepolymer and a prepolymerization reactor which forms an end reactor, the tower reactor configured in the lower third in the form of a hydrocyclone with a suspended heat exchanger and having a supply line for at least one of a paste, a slurry and a liquid raw material mixture, a static reaction mixer below the heat exchanger, a pressure line for coupling the hydrocyclone to the top side of the tower reactor, the top side of the tower reactor configured in its upper third in the form of a falling-film cascade, a line coupling the cascade to the middle part of the tower reactor, the cascade being configured in the form of one of a single step falling-film zone with prepressure reduction and a multi-step falling-film zone with prepressure reduction, the falling-film zones comprising falling-film pipes which have a filling comprising at least one of structured packing, filling materials, expanded metals and conducting spirals, the end reactor including a reactor housing including inner surfaces, end walls and a mounting device, a rotor which rotates in the reactor housing, the reactor having an inlet and outlet, the reactor including stub shaft arrangements extending beyond the end walls for mounting the reactor horizontally via the mounting device, annular film-forming elements disposed on the rotor, strippers disposed between the annular film-forming elements on the inner surfaces of the reactor housing, the cylindrical rotor having a heatable portion, and polycondensation thereof to form a high-molecular polyester in the polycondensation reactor comprising producing a prepolymer with >40 to 70 repeat units (DP) in the tower reactor and polycondensing this prepolymer in only the end reactor to form a polyester with >150 to 205 DP.