Final polycondensation reactor for preparing polycarbonate

Abstract

The invention discloses a final polycondensation reactor for preparing a polycarbonate, which comprises a horizontal cylindrical shell, the shell is provided with a feed port and a product outlet, thefeed port is connected with a feed pipeline, a rotary cylinder is arranged in the shell, the front end of the rotary cylinder is provided with an inlet, and the feed pipeline penetrates through the inlet and is inserted into the rotary cylinder; a driving shaft is arranged in the center of the rotary cylinder; a feeding disc is arranged at the front end, close to the inlet, in the rotary cylinder, a discharging disc is arranged at the rear end, and a supporting frame and a plurality of material passing discs are arranged in the middle. When the reactor disclosed by the invention runs, a prepolymer melt can completely infiltrate the inner surface of the cylinder and the surfaces of the material passing discs, the phenol removal rate is increased, the reaction rate is increased, excessive polymerization or side reaction caused by viscosity of part of materials is prevented, so that the residence time of all the prepolymers is narrow in distribution, and finally a polycarbonate product with narrow molecular weight distribution and low impurity content is obtained.

Description

technical field [0001] The invention relates to the field of polycarbonate production, in particular to a final polycondensation reactor for preparing polycarbonate. Background technique [0002] The final polycondensation reaction of the process of preparing polycarbonate by melt transesterification is an esterification reaction, and the precondensation melt is under high temperature and high vacuum conditions to generate small molecular product phenol and polycarbonate products. During the reaction process, it is necessary to continuously remove phenol and stir evenly to prevent part of the prepolymer from staying for a long time, excessive polycondensation and yellowing, and to promote the completion of the polycondensation reaction. [0003] The final polycondensation reactor is generally a horizontal disc reactor. Inside the disc reactor, the disc rotates to form a melt film, which increases the volatilization surface area, increases the volatilization speed of phenol, ...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a final polycondensation reactor for preparing polycarbonate, which solves the problems of uneven flow of high-viscosity materials inside the existing horizontal disc reactor, long-term residence of materials, and easy occurrence of side reactions

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