Chemistry of carbon compounds – Miscellaneous organic carbon compounds
Patent
1975-03-04
1977-07-26
Briggs, Sr., Wilbert J.
Chemistry of carbon compounds
Miscellaneous organic carbon compounds
260463, C08G 6362
Patent
active
040382524
ABSTRACT:
The present invention provides a process for the preparation of a polycarbonate by the phase boundary condensation method, by phosgenation of an aqueous alkali metal salt solution of one or more aromatic dihydroxy compounds, in which process an aromatic chlorinated hydrocarbon is used as the solvent and the synthesis of the polycarbonate is carried out in two stages, in the first stage of which the reaction of the alkali metal salt solution of the aromatic dihydroxy compound(s) with phosgene is carried out at an OH concentration of between 0.01 and 0.1% by weight of OH, relative to the aqueous phase, in the presence of 0.1 to 2.5 mol% of trialkylamine, relative to aromatic dihydroxy compound(s), and at a temperature higher than 70.degree. C, with a dwell time of less than 5 minutes, while in the second stage the polycondensation is effected by adjusting the OH concentration to 0.20 to 0.50% by weight of OH, relative to the aqueous phase, optionally with further addition of trialkylamine, at a temperature higher than 80.degree. C and with a dwell time of more than 1 minute.
REFERENCES:
patent: 3340229 (1967-09-01), Bostian et al.
patent: 3674740 (1972-07-01), Vernaleken et al.
patent: 3763099 (1973-10-01), Jaquiss
patent: 3912687 (1975-10-01), Haupt et al.
Hucks Uwe
Vernaleken Hugo
Bayer Aktiengesellschaft
Briggs Sr. Wilbert J.
Colen Frederick H.
Harsh Gene
Pope Lawrence S.
LandOfFree
Phase boundary process for the preparation of aromatic polycarbo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Phase boundary process for the preparation of aromatic polycarbo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase boundary process for the preparation of aromatic polycarbo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-725633