Process for the manufacture of polycarbonate-oligomers without solvent
AssigneeGeneral Electric Company
InventorNiles R. Rosenquist
Life of this patent
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Abstract
Polycarbonate oligomers having hydroxy end groups are produced by a melt reaction with bisphenol-A and a basic catalyst. The oligomers may then be reacted with chloro end-group siloxanes in the presence of a solvent and an acid acceptor to yield polycarbonate-polysiloxane block co-polymers. The melt reaction occurs at elevated temperature without the direct use of phosgene gas.
Claims24
A method for making a polycarbonate polysiloxane block co-polymer comprising melt reacting a polycarbonate resin having an intrinsic viscosity ranging from about 0.4 to about 1.6 dl/g in methylene chloride at 25.degree. C. and bisphenol-A in the presence of a basic catalyst and in the absence of both a solvent and phosgene to produce a hydroxyaryl terminated polycarbonate oligomer having an average of about 2 to about 50 chemically combined carbonate units, wherein the mole ratio of bisphenol-A to polycarbonate is in the range of about 1:50 to about 5:10 and reacting the hydroxyaryl terminated polycarbonate oligomer and a chlorine terminated polyorganosiloxane under substantially anhydrous conditions in an organic solvent and in the presence of an acid acceptor.
A method for making a polycarbonate polysiloxane copolymer comprising melt reacting a polycarbonate resin and a dihydric phenol in the presence of a basic catalyst and in the absence of a solvent and phosgene to produce a hydroxyaryl terminated polycarbonate oligomer having an average of about 2 to about 50 chemically combined carbonate units:
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- reacting the hydroxyaryl terminated polycarbonate oligomer and a chlorine terminated polydiorganosiloxane in an organic solvent and in the presence of an acid acceptor to form a polycarbonate-polysiloxane block co-polymer free of phosgene.
A polycarbonate-polysiloxane block copolymer prepared by reacting a hydroxy terminated polycarbonate oligomer made by the melt reaction of a polycarbonate resin and a dihydric phenol in the presence of a basic catalyst and in the absence of a solvent and a chlorine terminated polyorganosiloxane having an average of about 2 to about 100 chemically combined organosiloxy units in an organic solvent.
Dependencies are inferred from the claim text.