| US 7,528,214 B2 | ||
| Methods for preparing transparent articles from hydroquinone polycarbonate copolymers | ||
| Gautam Chatterjee, Bangalore (India); Patrick J. McCloskey, Watervliet, N.Y. (US); Warren W. Reilly, Northville, N.Y. (US); William D. Richards, Scotia, N.Y. (US); Subash Scindia, Bangalore (India); Gokul Srinivasan, Bangalore (India); and Yatin Tayalia, Bangalore (India) | ||
| Assigned to SABIC Innovative Plastics IP B.V., Bergen op Zoom (Netherlands) | ||
| Filed on Oct. 28, 2005, as Appl. No. 11/261,262. | ||
| Prior Publication US 2007/0100118 A1, May 03, 2007 | ||
| Int. Cl. C08G 63/02 (2006.01); C08G 63/00 (2006.01) | ||
| U.S. Cl. 528—198 [264/176.1; 264/219; 528/196; 548/472] | 33 Claims |
| 1. A method for producing a transparent article, the method comprising the steps of:
melt transesterifying a monomer mixture in the presence of a transesterification catalyst, said monomer mixture comprising
a hydroquinone, at least one aromatic dihydroxy compound other than the hydroquinone, and a carbonic acid diester to produce
a hydroquinone polycarbonate copolymer product comprising greater than 45 mole percent of structural units derived from the
hydroquinone, wherein the transesterification catalyst is in an amount of 1×10−7 to 1×10−2 moles catalyst per total moles of the hydroquinone and the at least one aromatic dihydroxy compound, and wherein the carbonic
acid diester is in an amount of 0.95 to 1.08 moles per mole of the hydroquinone and the at least one aromatic dihydroxy compound;
heating the hydroquinone polycarbonate copolymer product to a processing temperature of 5° C. to 20° C. above a maximum melting
melt temperature for the hydroquinone polycarbonate copolymer product for a period of time effective to render the hydroquinone
polycarbonate copolymer product transparent upon cooling to an ambient temperature; and
cooling the hydroquinone polycarbonate copolymer product to the ambient temperature to produce the transparent article.
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