| US 7,501,481 B2 | ||
| Process for production of copolycarbonates with reduced color | ||
| Jan Henk Kamps, Bergen op Zoom (Netherlands); and Jan Pleun Lens, Breda (Netherlands) | ||
| Assigned to Sabic Innovative Plastics IP B.V., Bergen op Zoom (Netherlands) | ||
| Appl. No. 10/597,586 PCT Filed Jan. 20, 2005, PCT No. PCT/US2005/002186 § 371(c)(1), (2), (4) Date Oct. 11, 2006, PCT Pub. No. WO2005/073274, PCT Pub. Date Aug. 11, 2005. |
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| Application 10/597586 is a continuation of application No. 10/768575, filed on Jan. 29, 2004, granted, now 7,057,004, filed on Jun. 06, 2006. | ||
| Prior Publication US 2008/0076902 A1, Mar. 27, 2008 | ||
| Int. Cl. C08G 64/00 (2006.01); C08G 63/02 (2006.01) | ||
| U.S. Cl. 528—196 [422/131; 422/135; 502/150; 502/208; 528/198] | 26 Claims |
| 1. A method of producing a copolycarbonate with improved color wherein the method comprises the steps of,
i. preparing a molten reaction mixture in a monomer mix tank wherein the reaction mixture comprises a first dihydroxy aromatic
compound comprising monomer residue (a), a second dihydroxy aromatic compound comprising monomer residue (b), and a carbonate
source,
wherein monomer residue (a) is a quinone structure, or a structure capable of forming a quinone structure upon oxidation,
wherein monomer residue (b) is a quinone structure, or a structure capable of forming a quinone structure upon oxidation different
from monomer residue (a) or is,
 where B is
 —O—, —CO—, —S—, —SO2—, a C6-C20 aromatic radical, or a C6-C20 cycloaliphatic radical; the groups R1 and R2 are independently a hydrogen atom, C1-C20 alkyl radical, C4-C20 cycloalkyl radical, or C4-C20 aryl radical; or R1 and R2 together form a C4-C20 cycloaliphatic ring which is optionally substituted by one or more C1-C20 alkyl, C6-C20 aryl, C5-C21 aralkyl, C5-C20 cycloalkyl groups or a combination thereof, R3 is a divalent hydrocarbylene group, and R4 and R5 are independently a hydrogen atom, halogen atom, nitro group, cyano group, C1-C20 alkyl radical C4-C20 cycloalkyl radical, or C6-C20 aryl radical and p and q are both integers from 0 to 4,
ii. introducing a polymerization catalyst to the reaction mixture or monomer residues prior to melting in said monomer mix
tank with the proviso that the residence time of the process from the start of melting until substantial polymerization has
occurred is less than 4 hours,
wherein the polymerization catalyst is an inorganic catalyst, an organic catalyst, or both an inorganic catalyst and an organic
catalyst which may be introduced separately or together,
iii. introducing the reaction mixture to a series of process units, wherein said series of process units comprises a plurality
of polymerization process units in which polymerization occurs and copolymer molecular weight increases, and
iv. allowing the reaction mixture to polymerize in the series of process units thereby forming copolycarbonate, wherein the
copolycarbonate has improved color as compared to a copolycarbonate formed in a melt process wherein said residence time is
not less than 4 hours.
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