The present invention relates to a process for preparing aromatic polycarbonates, comprising the step of reacting bisphenols with dithiocarbonates or selenium analogs thereof in the presence of a catalyst. It further relates to the use of dithiocarbonates or selenium analogs thereof as transesterifying reagents for the preparation of polycarbonates.

A method of preparing a poly(ester-carbonate) includes contacting an aqueous solution including a dicarboxylic acid with a first solution including phosgene and a first organic solvent in a tubular reactor to provide a first reaction mixture. A dihydroxy aromatic compound, the corresponding dialkali metal salt of the dihydroxy aromatic compound, or a combination comprising at least one of the foregoing, water, and a second organic solvent are combined to provide a second reaction mixture. The method further includes introducing the first reaction mixture, the second reaction mixture, and a second solution comprising phosgene to a tank reactor, wherein the tank reactor has a first pH of 7 to 10. The pH is optionally raised to 9 to 11 to provide a third reaction mixture including the poly(ester-carbonate). Poly(ester-carbonate)s prepared according to the method described herein are also disclosed.

In an embodiment, a continuous method of forming a bisphenol A oil comprises forming the bisphenol A oil by mixing a molten bisphenol A and water; wherein the bisphenol A oil comprises 10 to 30 wt % water based on a total weight of the bisphenol A oil and is at a temperature of 100 to 140 C.; flowing at least a portion of the bisphenol A oil through an inline densitometer and measuring a real-time density and a real-time temperature of the bisphenol A oil; determining a real-time concentration of the bisphenol A oil based on said real-time density and said real-time temperature.

A continuous process for producing a polysiloxane-polycarbonate block copolymer by polycondensation, comprising use of at least one thin-film evaporator, where this at least one thin-film evaporator includes at the circumference at least two wiper blade elements which rotate in the at least one thin-film evaporator. An oligocarbonate is reacted with a hydroxyaryl-terminated polysiloxane to afford a polysiloxane-polycarbonate block copolymer. In the reaction of the oligocarbonate with the hydroxyaryl-terminated polysiloxane using at least one thin-film evaporator, certain process parameters are observed. The polysiloxane-polycarbonate block copolymer produced has a small volume fraction of large polysiloxane domains at simultaneously narrow size distribution of the polysiloxane domains and exhibits good mechanical properties, in particular tough fracture behaviour, good processability, and good flowability.

A multi-stage process for continuous production of a polysiloxane-polycarbonate block copolymer by polycondensation is disclosed where in a first stage an oligocarbonate and a hydroxyaryl-terminated polysiloxane are provided and in a second stage at least one special condensation reactor is used. A certain amount of a particular co-catalyst is added and this co-catalyst is added upstream of the first special condensation reactor. The polysiloxane-polycarbonate block copolymer produced by the process according to the invention has a high proportion of small polysiloxane domains and features good mechanical properties, in particular tough fracture behaviour in the notched impact test according to ISO 7391/ISO 180A, good processability, for example in injection moulding or in extrusion, and good flowability.

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Provided is an aromatic polycarbonate wherein indicators of change in elongational viscosity measured at an elongation rate of 0.005 sec.sup.1 for a specimen 127 mm long, 12.7 mm wide, and 0.8 mm thick under a condition of 280 C. satisfy conditions (i) and (ii), and MFR at 300 C. under a load of 1.2 kg is 1.5 to 4.5 (g/10 min): <condition (i)> an indicator of change in elongational viscosity of the following formula (1):

[00001]$\begin{array}{cc}\left({\log }_{10}\left(\mathrm{Elongational}\mathrm{viscosity}\left[\mathrm{Pa}.Math.s\right]\mathrm{at}0.8\mathrm{seconds}\right)-{\log }_{10}\left(\mathrm{Elongational}\mathrm{viscosity}\left[\mathrm{Pa}.Math.s\right]\mathrm{at}0.3\mathrm{seconds}\right)\right)/\left({\log }_{10}0.8-{\log }_{10}0.3\right)& \mathrm{formula}\left(1\right)\end{array}$

in interval A (interval from 0.30 to 0.80 seconds after the start of elongation) is 0.10 to 0.30; and <condition (ii)> an indicator of change in elongational viscosity of the following formula (2):

[00002]$ ( log 10 ( Elongational viscosity [ Pa .Math. s ] at 8. seconds ) - log 10 ( Elongational viscosity [ Pa .Math. s ] at PROCESS FOR PREPARING POLYCARBONATES BY TRANSESTERIFYING DITHIOCARBONATES OR SELENIUM ANALOGUES THEREOF WITH BISPHENOLS 20180037697 · 2018-02-08 · Thomas Ernst Müller, Christoph Gürtler, Nicolai Kolb, Burkhard Köhler, Walter Leitner, Jan HEIJL, Alexandra Große Böwing The present invention relates to a process for preparing aromatic polycarbonates, comprising the step of reacting bisphenols with dithiocarbonates or selenium analogues thereof in the presence of a catalyst. It further relates to the use of dithiocarbonates or selenium analogues thereof as transesterifying reagents for the preparation of polycarbonates. Continuous manufacturing of polyol 12215187 · 2025-02-04 · Saudi Arabian Oil Company · Mohammad S. Alroaithi, Hussain M. Yami, Ola Ali, Wei Xu A method of continuously producing a polyol includes: (i) feeding a solid catalyst into a continuous stirred tank reactor (CSTR); (ii) contacting a reaction mixture comprising one or more epoxides and carbon dioxide with the solid catalyst and a chain transfer agent comprising a plurality of sites capable of initiating copolymerization of epoxides and carbon dioxide in the CSTR; (iii) allowing polymerization reaction to proceed until a desired molecular weight polyol has formed; and (iv) terminating the polymerization reaction. Method for the Production of Polyether Carbonate Polyols and Device Therefor 20170198092 · 2017-07-13 · Stefanie Braun, Horst Zwick, Matthias Wohak, Jörg Hofmann, Aurel Wolf, Michael Traving, Rolf Bachmann The present invention relates to a method for producing polyether carbonate polyols by addition of one or more alkylene oxides and carbon dioxide to one or more H-functional starter substances in the presence of at least one DMC catalyst, in which the reaction is conducted in a main reactor (8) and a tubular reactor (11, 17) connected as a post reactor downstream thereof, wherein the method is characterized in that at the outlet (13) of the tubular reactor (11, 17) a temperature is set that is at least 10 C. above the temperature in the inside of the main reactor (8). The invention further relates to a device for carrying out said method. $