Oligomeriser with an improved feed system

Patent metadata

Field	Value
Publication number	US-11529602-B2
Application number	US-201816625926-A
Country	US
Kind code	B2
Filing date	Jun 29, 2018
Priority date	Jun 30, 2017
Publication date	Dec 20, 2022
Grant date	Dec 20, 2022

Abstract

In an embodiment, a reactor for carrying out a melt transesterification reaction at a reactor temperature of 160 to 300° C. and a reactor pressure of 5 to 200 mbar, comprises a cylindrical tank comprising a top, a side, and a bottom, wherein the bottom is convex, extending away from the top; a stirring shaft disposed within the cylindrical tank along an axis thereof so that it is rotatable from outside of the cylindrical tank; a stirring blade extending from the stirring shaft in the cylindrical tank; a reactant solution inlet located on the bottom; and a reaction solution outlet located on the bottom. The reactor can be used for the polymerization of a polycarbonate oligomer.

First claim

What is claimed is:

1. A method of melt polymerizing a polycarbonate, comprising:
adding a precursor solution comprising a polycarbonate precursor through a reactant solution inlet of a reactor for carrying out a melt transesterification, said reactor comprising:
a cylindrical tank comprising a top, a side, and a bottom, wherein the bottom is convex, extending away from the top; a stirring shaft disposed within the cylindrical tank along an axis thereof so that it is rotatable from outside of the cylindrical tank; a stirring blade extending from the stirring shaft in the cylindrical tank; a reactant solution inlet located on the bottom; and a reaction solution outlet located on the bottom; wherein the stirring shaft is disposed from a top of the cylindrical tank along the axis thereof; the reactant solution outlet is located on the bottom of the cylindrical tank and along the axis of the stirring shaft; and the reaction solution inlet is located on the bottom of the cylindrical tank at a location outside of a rotation column of the stirring blade;
reacting the polycarbonate precursor at the reactor temperature of 160 to 300° C. and the reactor pressure of 5 to 200 mbar to form a mixed solution comprising a polycarbonate oligomer having a weight average molecular weight that is greater than that of the polycarbonate precursor;
withdrawing the mixed solution from the reaction solution outlet; and
polymerizing the polycarbonate oligomer to form the polycarbonate.

2. The method of claim 1 , wherein the mixed solution has a mixed solution viscosity of 0.15 to 10 Pa·s.

3. The method of claim 1 , wherein the mixed solution has a mixed solution viscosity that is greater than a precursor solution viscosity of the precursor solution.

4. The method of claim 1 , further comprising adding a catalyst to the reactor.

5. The method of claim 1 , further comprising, prior to the polymerizing, directing the mixed solution into a second reactor;
mixing the mixed solution at a second temperature greater than the reactor temperature and a second pressure less than the reactor pressure; and
withdrawing an oligomer solution comprising a high molecular weight polycarbonate oligomer having a weight average molecular weight that is greater than that of the polycarbonate oligomer from the reaction solution outlet.

6. The method of claim 5 , wherein the high molecular weight polycarbonate oligomer has a weight average molecular weight of 1.5 to 15 kilodaltons based on polycarbonate standards.

7. The method of claim 1 , wherein the precursor solution comprises bisphenol A and diphenyl carbonate.

8. The method of claim 1 , wherein the average residence time is 0.1 to 15 hours.

9. The method of claim 1 , wherein the reacting comprises mixing the polycarbonate precursor with the stirring blade, wherein the stirring blade is a flat plate impeller has a plurality of openings.

10. The method of claim 1 , wherein the reacting comprises mixing the polycarbonate precursor with the stirring blade, wherein the stirring blade is a hydrofoil impeller.

11. A method of melt polymerizing a polycarbonate, comprising:
adding a precursor solution comprising a polycarbonate precursor through a reactant solution inlet of a reactor for carrying out a melt transesterification, said reactor comprising:
a cylindrical tank comprising a top, a side, and a bottom, wherein the bottom is convex, extending away from the top; a stirring shaft disposed within the cylindrical tank along an axis thereof so that it is rotatable from outside of the cylindrical tank; a stirring blade extending from the stirring shaft in the cylindrical tank; a reactant solution inlet located on the bottom; and a reaction solution outlet located on the bottom;
reacting the polycarbonate precursor at the reactor temperature of 160 to 300° C. and the reactor pressure of 5 to 200 mbar to form a mixed solution comprising a polycarbonate oligomer having a weight average molecular weight that is greater than that of the polycarbonate precursor;
maintaining the reactor temperature via a plurality of heating coils located in the cylindrical tank that are supported by a plurality of supports; wherein an innermost diameter of the heating coils is greater than an outermost diameter of the stirring blade;
withdrawing the mixed solution from the reaction solution outlet; and
polymerizing the polycarbonate oligomer to form the polycarbonate.

Assignees

• Sabic Global Technologies Bv

Inventors

• Fernandez Ignacio Vic
• Mateos Salvador Fernan
• Daliparthi Surya Prakasa Rao

Classifications

• B01J2219/1943

  cylindrical · CPC title

• B01F27/1131

  with holes in the propeller blade surface · CPC title

• B01J19/0066

  Stirrers (mixing per se B01F) · CPC title

• C08G64/307

  and phenols · CPC title

• B01J2219/00779

  Baffles attached to the stirring means · CPC title