Vorrichtung zur kontinuierlichen Herstellung von Polykondensaten

摘要

A polycondensable mixture is reacted in a continuous process by feeding it into a reactor having a stirrer or boundary wall in rotation or rotary oscillation about a horizontal or inclined axis through which flows a polymer containing liquid the stirrer or boundary wall being heated only at a point which is in contact with the liquid. The polycondensate may be a saturated linear or unsaturated polyester, a polyether or a polyamide. The reactor may be conical or cylindrical in shape and may contain annular partitions at right angles to the rotating wall. It may be 1/4 -/ba1/3 full. Additional agitation may be provided by (a) metal balls, (b) an axially mounted agitator in the form of a disc, blade or screw which is stationary or rotating at a different speed to the reactor, (c) baffle plates or (d) inclination of the reactor. Heat may be supplied by electrical means or by immersing 1/4 or 1/3 of the reactor in a hot fluid bath. The electrical heating means may comprise a number of elements either arranged as blades of a stirrer, or fixed to the outside of the rotating boundary wall coupled to equipment which allows them to be switched on and off in rotation. The reaction may be carried out in a number of stages each stage being a process as previously described but the speed of rotation and degree of heating decreasing in the direction in which the polymer flows. Several embodiments of the invention are illustrated. In an example polyethylene terephthalate is prepared using a zinc acetate catalyst.