Lg Chem, Ltd

Mijeung Hong

Jong-Hun Kim

Jong Hun Kim

Boo Gon Woo

Boo-Gon Woo

Sung Kyou Park

Jong-Hun 101-1507 Cheongsol Apt Kim

Jong-Hun 101-1507 Cheongsol Apt 8-2 Kim

Sung-Kyou Park

Boo-Gon 8-401 Lg Company Housing Apt Woo

A method of preparing a polycarbonate resin having improved thermal stability is provided. The method includes: mixing polycarbonate having hydroxy terminal groups and a end terminator, a compound of formula (1) (refer to the detailed description section) at normal temperature and pressure to obtain a mixture; and performing a melt reaction on the mixture at 250-320&#xb0; C. and reduced pressure to highly reduce the final concentration of the hydroxy terminal groups of the polycarbonate resin.

Method of preparing polycarbonate resin

Provided is a method of producing a high-molecular weight modified polycarbonate resin. The method includes a melt condensation polymerization process in which transesterification and quick condensation polymerization are sequentially performed, a spray crystallization process, and a solid state polymerization process. When this method is used, solid state polymerization can be performed without additional drying, milling and fractionation processes so that the operation time and costs are highly reduced. In addition, crystallinity and size of crystallized modified polycarbonate particles can be efficiently controlled to produce a high-molecular weight modified polycarbonate having uniform physical properties in the solid state polymerization.

Method of producing modified polycarbonate using spray-crystallizing method

A method of preparing a high molecular weight polycarbonate resin is provided. In the method, a condensation polymerization process is used so that a mole fraction of arylcarbonate existing in a terminated group of a reaction side product having a degree of polymerization of less than 3 obtained as a result of transesterification and in a non-reacted diarylcarbonate is reduced. As a result, a high molecular weight polycarbonate can be obtained by solid state polymerization. A polycarbonate with an identical molecular weight can be produced in a substantially short time, compared with a polycarbonate produced through solid state polymerization without condensation polymerization. In addition, the non-use of a poisonous phosgene contributes to stability. Furthermore, quality polycarbonate may be guaranteed.

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Daejeon, South Korea

Mijeung Hong