| US 7,601,794 B2 | ||
| Monomer solution for producing polycarbonate | ||
| Hans-Peter Brack, Herrliberg (Switzerland); Maarten Antoon Jan Campman, Churra-Murcia (Spain); Yohana Perez de Diego, Murcia (Spain); Martin Herke Oyevaar, Goes (Netherlands); Laurus van der Wekke, Rucphen (Netherlands); and Dennis Willemse, Standdaarbuiten (Netherlands) | ||
| Assigned to Sabic Innovative Plastics IP B.V., Bergen op Zoom (Netherlands) | ||
| Filed on Sep. 28, 2007, as Appl. No. 11/863,659. | ||
| Prior Publication US 2009/0088540 A1, Apr. 02, 2009 | ||
| Int. Cl. C08G 64/00 (2006.01); C08G 63/62 (2006.01) | ||
| U.S. Cl. 528—196 [422/56; 422/57; 422/62; 422/75; 436/75; 436/79; 436/85; 436/95; 436/106; 436/111; 528/198] | 25 Claims |
| 1. A method of forming a non-reactive monomer mixture suitable for use in a melt transesterification reaction to form polycarbonate,
the method comprising the steps of:
(i) providing a diaryl carbonate;
(ii) selecting a first dihydroxy compound,
(iii) performing a dihydroxy conditioning step selected from the group consisting of:
(a) testing the first dihydroxy compound for the presence of alkali metal prior to forming the non-reactive monomer mixture,
and if said alkali metal is present, performing a step selected from the group consisting of:
(I) treating the first dihydroxy compound to reduce the level of said alkali metal to an amount of less than 600 ppb,
(II) adding an acid stabilizer to the first dihydroxy compound, and
(III) a combination of steps (I) and (II), and
(b) treating the first dihydroxy compound with a step selected from the group of:
(I) treating the first dihydroxy compound to reduce the level of said alkali metal to an amount of less than 600 ppb,
(II) adding an acid stabilizer to the first dihydroxy compound, and
(III) a combination of steps (I) and (II),
(iv) adjusting the temperature of the diaryl carbonate to a first temperature that is:
greater than the melting point of the diaryl carbonate; and
below the melting point of the first dihydroxy compound;
(v) adding the first dihydroxy compound as a solid to the diaryl carbonate,
wherein the first temperature is selected such that the first dihydroxy compound added to the diaryl carbonate dissolves in
the diaryl carbonate to produce a non-reactive monomer mixture.
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