# US 5,344,908 A · Process for the manufacture of polycarbonate-oligomers without solvent > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,344,908 A - Document ID: US5344908A - Status: Granted - Kind: A - Application number: 08/058,070 - Filed: 1993-05-04 - Granted: 1994-09-06 - Earliest claimed: 1993-05-04 - Assignees: General Electric Company - Inventors: Niles R. Rosenquist - Web page: https://patentgrep.com/patent/US5344908A ## CPC - C08G 64/186: {containing polysiloxane sequences} - C08G 77/448: containing polycarbonate sequences - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The method according to claim 1, wherein the polyorganosiloxane has an average chain length of 2 to about 100 chemically combined organosiloxy units. ### Claim 3 (depends on 1) The method according to claim 1, wherein the polyorganosiloxane has an average chain length of 5 to about 60 chemically combined organosiloxy units. ### Claim 4 (depends on 1) The method according to claim 1, wherein the polyorganosiloxane has an average chain length of 7 to about 12 chemically combined organosiloxy units. ### Claim 5 (depends on 1) The method according to claim 1, wherein the polyorganosiloxane is a chlorine terminated polydimethylsiloxane having about 8 to about 10 dimethylsiloxane units. ### Claim 6 (depends on 1) The method according to claim 1, wherein the basic catalyst comprises at least one member selected from the group consisting of: tetrabutylammonium tetraphenylborate, tetraethylammonium hydroxide, and tetramethylammonium hydroxide. ### Claim 7 (depends on 1) The method according to claim 1, wherein the catalyst is present in a range of from about 0.005 to about 0.1 mole percent. ### Claim 8 (depends on 1) A polycarbonate-polysiloxane block co-polymer prepared by the method of claim 1 wherein the chlorine terminated polyorganosiloxane has an average of about 2 to about 100 chemically combined organosiloxy units wherein the co-polymer is free of phosgene. ### Claim 9 (depends on 8) The polycarbonate-polysiloxane copolymer of claim 8, wherein the polyorganosiloxane has an average of about 2 to about 60 chemically combined organosiloxy units. ### Claim 10 (depends on 8) The polycarbonate-polysiloxane copolymer of claim 8, wherein the polyorganosiloxane has an average of about 5 to about 60 chemically combined organosiloxy units. ### Claim 11 (depends on 8) The polycarbonate-polysiloxane copolymer of claim 8, wherein the polyorganosiloxane has an average of about 7 to about 12 chemically combined organosiloxy units. ### Claim 12 (depends on 8) The polycarbonate-polysiloxane copolymer of claim 8, wherein the polyorganosiloxane comprises a chlorine terminated polydimethylsiloxane having about 8 to about 10 dimethylsiloxane units. ### Claim 13 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: and 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. ### Claim 14 (depends on 13) The method according to claim 13, wherein the dihydric phenol is bisphenol-A (BPA). ### Claim 15 (depends on 13) The method according to claim 13, wherein the polycarbonate oligomer has from about 2 to about 15 carbonate units. ### Claim 16 (depends on 13) The method according to claim 13, wherein the polycarbonate oligomer has from about 3 to about 6 carbonate units. ### Claim 17 (depends on 13) The method according to claim 13, wherein the mole ratio of BPA to polycarbonate is-about 2:10 to about 4:10. ### Claim 18 (depends on 13) The method according to claim 13, wherein the catalyst comprises at least one member selected from the group consisting of: tetrabutylammonium tetraphenylborate, tetraethylammonium hydroxide, and tetramethylammonium hydroxide. ### Claim 19 (depends on 13) The method according to claim 13, wherein the catalyst is present in a range from about 0,005 to about 0.1 mole percent. ### Claim 20 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. ### Claim 21 (depends on 20) The copolymer according to claim 20, wherein the dihydric phenol is bisphenol-A. ### Claim 22 (depends on 20) The copolymer according to claim 20, wherein the polycarbonate oligomer has from about 2 to about 15 carbonate units. ### Claim 23 (depends on 20) The copolymer according to claim 20, wherein the polycarbonate oligomer has from about 3 to about 6 carbonate units. ### Claim 24 (depends on 21) The copolymer according to claim 21, wherein the mole ratio of bisphenol-A to polycarbonate is about 2: 10 to about 4:10.