Abstract:
A process for purifying a diaryl carbonate, comprises introducing an aqueous stream to a diaryl carbonate stream that comprises a metal contaminant, wherein the aqueous stream reacts with the metal contaminant to form a precipitate; wherein introducing the aqueous stream to the diaryl carbonate stream results in introducing 100 to 10,000 ppm water based on the total composition of the diaryl carbonate stream and the aqueous stream; removing the precipitate via one or both of a separation column and a filter to result in a purified diaryl carbonate.
Abstract:
A method for producing a polycarbonate comprising: reacting a diaryl carbonate with a dihydroxy compound to form a polycarbonate, wherein the polycarbonate comprises: less than or equal to 1000 ppb of molybdenum; less than or equal to 33 ppb of vanadium; less than or equal to 33 ppb of chromium; less than or equal to 375 ppb of niobium; less than or equal to 33 ppb of nickel; less than or equal to 10 ppb of zirconium; and less or equal to 10 ppb iron.
Abstract:
A method for producing a polycarbonate comprising: reacting a diaryl carbonate with a dihydroxy compound to form a polycarbonate, wherein the polycarbonate comprises: less than or equal to 1000 ppb of molybdenum; less than or equal to 33 ppb of vanadium; less than or equal to 33 ppb of chromium; less than or equal to 375 ppb of niobium; less than or equal to 33 ppb of nickel; less than or equal to 10 ppb of zirconium; and less or equal to 10 ppb iron.
Abstract:
A method for producing polycarbonate by melt polymerization can comprise: (a) adding acetone, diaryl carbonate, and dihydroxy compound to the melt polymerization unit, wherein the acetone is added to the melt polymerization unit as a mixture with the diaryl carbonate and/or the dihydroxy compound; (b) adding a catalyst to the melt polymerization unit, optionally without separating out acetone prior to the addition of the catalyst; and (c) operating the melt polymerization unit under conditions so that the diaryl carbonate(s) and dihydroxy compound(s); dihydroxy compound reacts with the diaryl carbonate to produce polycarbonate with a desired specification, and a phenol by-product.
Abstract:
A method for producing polycarbonate by melt polymerization can comprise: (a) adding acetone, diaryl carbonate, and dihydroxy compound to the melt polymerization unit, wherein the acetone is added to the melt polymerization unit as a mixture with the diaryl carbonate and/or the dihydroxy compound; (b) adding a catalyst to the melt polymerization unit, optionally without separating out acetone prior to the addition of the catalyst; and (c) operating the melt polymerization unit under conditions so that the diaryl carbonate(s) and dihydroxy compound(s); dihydroxy compound reacts with the diaryl carbonate to produce polycarbonate with a desired specification, and a phenol by-product.