EP 1794208 A1 20070613 - METHOD FOR PRODUCING POLYCARBONATE
Title (en)
METHOD FOR PRODUCING POLYCARBONATE
Title (de)
VERFAHREN ZUR HERSTELLUNG VON POLYCARBONAT
Title (fr)
PROCEDE DE PRODUCTION D'UN POLYCARBONATE
Publication
Application
Priority
- EP 2005009911 W 20050915
- DE 102004045822 A 20040922
Abstract (en)
[origin: US2006063906A1] A process for the preparation of polycarbonate by the phase interface process is disclosed. The process includes (a) preparing a sodium hydroxide solution by chloralkali electrolysis, the solution containing not more than 30 ppm sodium chlorate relative to the weight of sodium hydroxide, and (b) reacting an aqueous solution of said sodium hydroxide with at least one dihydoxydiarylalkane to obtain a solution of disodium salt and (c) reacting said solution of disodium salt with phosgene in the presence of at least one organic solvent, a chain terminator and optionally a branching agent to obtain an oligocarbonate, and (d) condensing the oligocarbonate in the presence of at least one catalyst to obtain a material system containing polycarbonate and organic solvent and (e) separating off of the organic phase from said material system. The polycarbonate prepared by the inventive process is characterized by its low yellowness index.
IPC 8 full level
C08G 64/24 (2006.01)
CPC (source: EP KR US)
C08G 64/00 (2013.01 - KR); C08G 64/04 (2013.01 - KR); C08G 64/22 (2013.01 - KR); C08G 64/24 (2013.01 - EP KR US)
Citation (search report)
See references of WO 2006032401A1
Designated contracting state (EPC)
BE DE ES NL
DOCDB simple family (publication)
US 2006063906 A1 20060323; CN 101023118 A 20070822; DE 102004045822 A1 20060406; EP 1794208 A1 20070613; JP 2008513590 A 20080501; KR 20070056106 A 20070531; RU 2007114944 A 20081027; WO 2006032401 A1 20060330
DOCDB simple family (application)
US 22609305 A 20050914; CN 200580031853 A 20050915; DE 102004045822 A 20040922; EP 05784029 A 20050915; EP 2005009911 W 20050915; JP 2007532807 A 20050915; KR 20077006464 A 20070321; RU 2007114944 A 20050915