Lg Chem, Ltd

Mi-Jeung Hong

Boo-Gon Woo

Jong-Hun Kim

Eun-duck Park

Moo-Ho Hong

Ja-Hun Kwak

The present invention relates to a continuous method for the preparation of an aromatic carbonate by reacting a dialkyl carbonate and an aromatic hydroxy compound in the presence of a heterogeneous catalyst, and a reaction apparatus for the same. The continuous method comprises the step of reacting dialkyl carbonate and an aromatic hydroxy compound in the presence of the heterogeneous catalyst in a loop-type, catalyst-containing reaction apparatus, wherein a reactor equipped with a filter in which the catalyst is contained is connected with a heat exchanger portion for providing necessary heat during the reaction, reaction solution is circulated between the catalyst-containing portion and heat exchanger via a circulation pump, and by-products can be eliminated via a distillation column connected with the reactor.

Continuous method for preparing aromatic carbonate using a heterogeneous catalyst and a reaction apparatus for the same

The present invention relates to a method for preparing polycarbonate resin, and more particularly to a method for effectively preparing polycarbonate resin having a large molecular weight in a short time under a melt polymerization condition using a catalyst system comprising phosphoranylidene ammonium salts, which is stable and maintains superior reactivity during melt polymerization and solid state polymerization.

Method for preparing polycarbonate resin

The present invention relates to a method for the preparation of a high molecular weight polycarbonate resin, and more particularly to a method for preparing a high molecular weight polycarbonate resin using a solid state polymerization method after the preparation of a crystalline polycarbonate or-conducting the preparation of the crystalline polycarbonate and the solid state polymerization thereof simultaneously. According to the method for the preparation of a high molecular weight polycarbonate resin of the invention, it is possible to produce a high molecular weight polycarbonate resin having a narrow molecular weight distribution and uniform properties and that is applicable to injection and extrusion in large quantities with a low cost within a short time.

Preparation method of high molecular weight polycarbonate resin

The present invention relates to a process for preparing high molecular weight polycarbonate resin, particularly to a process for preparing high molecular weight polycarbonate resin, which conducts condensation polymerization of low molecular weight amorphous polycarbonate prepolymer prepared by transesterification of dialkyl(aryl)carbonate and aromatic hydroxy compound and solid state polymerization within short time to increase molecular weight. The present invention introduces condensation polymerization to lower mole fractions of arylcarbonate existing in unreacted diarylcarbonate, end groups of reaction by products of polymerization degree less than 3, and polycarbonate prepolymer obtained by transesterification, and thus can maximize molecular weight increase of polycarbonate after solid state polymerization and remarkably reduce time required for preparing polycarbonate of the same molecular weight. In addition, since the present invention does not use toxic substance phosgene, it has no danger and it can prevent deterioration, and it can prepare high molecular weigh polycarbonate that can be used for injection and extrusion.

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Daejeon, South Korea

Mi-Jeung Hong