Patent ID: 7232865
Filing Date: 2007-06-19
Classification: C08G,C08L

Abstract:
1. A method for preparing an aromatic bischloroformate mixture, the method comprising the step of: combining one or more aromatic dihydroxy compounds with phosgene, a phase transfer catalyst, an aqueous solvent and an organic solvent under interfacial reaction conditions while maintaining the pH in the range of about 3 to about 8, wherein the phase transfer catalyst is present in an amount that is effective for catalyzing a reaction between the phosgene and the one or more aromatic dihydroxy compounds, and carrying out the reaction until about 105 to about 150 mole percent of phosgene has been added based on the total moles of available hydroxy groups of the one or more aromatic dihydroxy compounds, thus producing an aromatic bischloroformate mixture.