Method for manufacturing diaryl carbonates from dialkyl carbonates

摘要

Preparing at least a diaryl carbonate, comprises (a) preparing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide; (b) reacting the alkylene carbonate with at least an alkyl alcohol to obtain at least a dialkyl carbonate and alkylene glycol; (c) separating and reconditioning at least a portion of the dialkyl carbonate; (d) separating and optionally purifying at least a portion of the dialkyl carbonate; and (e) oxidative carbonylation of at least a portion of separated alkylene glycol with carbon monoxide to alkylene carbonate. Preparing at least a diaryl carbonate from at least a dialkyl carbonate and at least an aryl hydroxy compound, comprises (a) preparing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide; (b) reacting the alkylene carbonate with at least an alkyl alcohol in the presence of a catalyst, and optionally an organic solvent to obtain at least a dialkyl carbonate and alkylene glycol; (c) separating and reconditioning at least a portion of the dialkyl carbonate; (d) separating and optionally purifying at least a portion of the dialkyl carbonate; (e) oxidative carbonylation of at least a portion of separated alkylene glycol with carbon monoxide to alkylene carbonate under the formation of water; (f) separating and optionally purifying least a portion of the alkylene carbonate; (g) recycling at least a portion of the separated alkylene carbonate in the preparation of dialkyl carbonate in the step (b); (h) reacting at least a portion of the dialkyl carbonate with a monophenol to obtain alkyl aryl carbamate and/or diaryl carbonate and alkyl alcohol, where the alkyl alcohol is optionally used in the step (b); (i) disproportionating at least a portion of alkyl aryl carbonate to diaryl carbonate and dialkyl carbonate; and (j) transesterifying at least a portion of the diaryl carbonate with a bisphenol to oligo-/polycarbonate and the monophenol, where the monophenol is optionally used in the step (h). An independent claim is included for a polycarbonate obtained by the above process.