Provided herein are methods of making polyalkylene carbonate compositions. The methods provided herein may comprise one or more of the following steps: (1) a polymerization step wherein an alkylene oxide is contacted with carbon dioxide, optionally in the presence of a catalyst, thereby forming a polyalkylene carbonate; (2) a dissolution step wherein the polyalkylene carbonate is dissolved in an organic solvent, thereby forming a polyalkylene carbonate solution; (3) a heat treatment step wherein a polyalkylene carbonate composition is heated, thereby forming a heat-treated poyalkylene carbonate composition; and (4) an irradiation step wherein a composition comprising polyalkylene carbonate is exposed to ionizing radiation, thereby providing an irradiated polyalkylene carbonate composition

A recycled cyclic carbonate composition and a method for manufacturing same, the composition including an alkylene carbonate and a phenolic compound whose mass ratio, measured using .sup.1H NMR, is 5 mass % or less relative to the total mass of the composition, and wherein the recycled cyclic carbonate composition is a recovered product from a polycarbonate-based resin.

A recycled cyclic carbonate composition and a method for manufacturing same, the composition including an alkylene carbonate and a phenolic compound whose mass ratio, measured using .sup.1H NMR, is 5 mass % or less relative to the total mass of the composition, and wherein the recycled cyclic carbonate composition is a recovered product from a polycarbonate-based resin.

A method for producing a polycarbonate, comprising a polymerization step of polymerizing a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof in a polymerization reactor, a washing step of contacting a discharged vapor containing the hydroxyaryl compound, the diaryl carbonate and the dihydroxy compound, discharged from the polymerization reactor in the polymerization step, with a washing liquid in a scrubber, and a condensation step of condensing the discharged vapor washed in the washing step, wherein at least a portion of a bottom liquid of the scrubber in the washing step is supplied to the polymerization reactor.

A method for producing a polycarbonate, comprising a polymerization step of polymerizing a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof in a polymerization reactor, a washing step of contacting a discharged vapor containing the hydroxyaryl compound, the diaryl carbonate and the dihydroxy compound, discharged from the polymerization reactor in the polymerization step, with a washing liquid in a scrubber, and a condensation step of condensing the discharged vapor washed in the washing step, wherein at least a portion of a bottom liquid of the scrubber in the washing step is supplied to the polymerization reactor.

The present invention relates to the use of an ultraviolet stabilising compound comprising at least one benzotriazole group as a heat stabiliser in polycarbonate manufactured by means of a melt transesterification process comprising reacting diaryl carbonate and bisphenol catalysed by a catalyst and quenching the catalyst with a quencher.

The present invention relates to the use of an ultraviolet stabilising compound comprising at least one benzotriazole group as a heat stabiliser in polycarbonate manufactured by means of a melt transesterification process comprising reacting diaryl carbonate and bisphenol catalysed by a catalyst and quenching the catalyst with a quencher.

The present invention is capable of providing a method for producing a refined polycarbonate resin by removing unreacted dihydroxy compounds contained as impurities in a polycarbonate resin following polymerization. This production method includes: (i) a step for dissolving said polycarbonate resin following polymerization in an organic solvent, and filtering to prepare a 1-30 mass % resin solution or (ii) a step for preparing, by means of interfacial polymerization, a 1-30 mass % resin solution in which a polycarbonate resin is dissolved in an organic solvent following interfacial polymerization; and a step for passing the obtained resin solution through a column chromatograph to remove unreacted dihydroxy compounds contained as impurities in the polycarbonate resin following polymerization.