Low shear process for polycarbonate purification

Patent metadata

Field	Value
Publication number	US-2016168322-A1
Application number	US-201414907349-A
Country	US
Kind code	A1
Filing date	Jul 25, 2014
Priority date	Jul 25, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

In another embodiment, a process of purifying an interfacially polymerized polycarbonate from a feed comprising an aqueous phase and an organic phase comprising an organic solvent, the interfacially polymerized polycarbonate, a catalyst, and ions, can comprise: separating the aqueous phase and the organic phase from the feed, wherein during the separating the feed is subjected to at least one of: energy of less than or equal to 0.5 kJ/kg of feed, a shear rate of less than 150,000 S −1 , and centrifugal forces of 100 to 2,000 g-force; to form a purified aqueous phase and a purified organic phase comprising a purified polycarbonate.

First claim

I/we claim:

1 . A process of purifying a polycarbonate from a feed comprising an interfacial polymerization product mixture, wherein the product mixture comprises an aqueous phase and an organic phase comprising an organic solvent, the polycarbonate, a catalyst, and ions, the process comprising:
separating the aqueous phase and the organic phase while subjecting the product mixture to a shear rate of less than 150,000 S 1 to form a separated organic phase and a separated aqueous phase; extracting the catalyst from the separated organic phase with an acid stream while subjecting the separated organic phase and the acid stream to a shear rate of less than 150,000 S −1 ; and extracting the ions from the separated organic phase with a water stream while subjecting the separated organic phase and the water stream to a shear rate of less than 150,000 S −1 ; to form a purified organic phase comprising a purified polycarbonate.

2 . A process of making a purified polycarbonate, comprising:
interfacially polymerizing a polycarbonate to form a product mixture; wherein the product mixture comprises an aqueous phase and an organic phase comprising an organic solvent, the polycarbonate, a catalyst, and ions; separating the aqueous phase and the organic phase while subjecting the product mixture to a shear rate of less than 150,000 S 1 to form a separated organic phase and a separated aqueous phase; extracting the catalyst from the separated organic phase with an acid stream while subjecting the separated organic phase and the acid stream to a shear rate of less than 150,000 S −1 ; and extracting the ions from the separated organic phase with a water stream while subjecting the separated organic phase and the water stream to a shear rate of less than 150,000 S −1 ; forming a purified organic phase comprising the purified polycarbonate.

3 . The process of any of claim 1 , wherein one or more of the separating, the extracting of the catalyst, and the extracting of the ions, is at a shear rate of 0.5 to less than 100,000 S −1 .

4 . A process of purifying an interfacially polymerized polycarbonate from a feed comprising an aqueous phase and an organic phase comprising an organic solvent, the interfacially polymerized polycarbonate, a catalyst, and ions, the process comprising:
separating the aqueous phase and the organic phase from the feed, wherein during the separating the feed is subjected to at least one of: energy of less than or equal to 0.5 kJ/kg of feed, a shear rate of less than 150,000 S −1 , and centrifugal forces of 100 to 2,000 g-force, to form a purified aqueous phase and a purified organic phase comprising a purified polycarbonate.

5 . The process of claim 4 , further comprising
interfacially polymerizing the interfacially polymerized polycarbonate.

6 . The process of claim 4 , wherein the feed comprises an organic wash stream and wherein the process further comprises extracting the organic wash stream with an extracting aqueous stream prior to the separating.

7 . The process of claim 4 , wherein the feed is subjected to the energy of 0.001 to 0.5 kJ/kg of feed.

8 . The process of claim 4 , wherein the feed is subjected to the shear rate of 0.5 to less than 100,000 S −1 .

9 . The process of claim 1 , wherein the separating is at a shear rate of 0.5 to less than 100,000 S −1 .

10 . The process of claim 1 , further comprising increasing a size of an aqueous droplet in the organic phase in a low shear rate coalescer to form a coalesced mixture.

11 . The process of claim 1 , wherein the separated aqueous stream comprises less than or equal to 10 vol % of the organic phase.

12 . The process of claim 1 , wherein the separated organic phase has a viscosity of less than or equal to 100 centipoise.

13 . The process of claim 1 , wherein the separating comprises separating with a low shear centrifuge, wherein the low shear centrifuge is free of a rotating disc and a rotating screw, wherein the process further comprises introducing the feed to an annular mixing zone in the low shear centrifuge.

14 . The process of claim 1 , further comprising determining that the product mixture emulsifies at shear rate of greater than or equal to 150,000 S −1 prior to the separating.

15 . The process of claim 1 , further comprising determining that one or both of the separated aqueous phase and the separated organic phase emulsifies at shear rate greater than or equal to 150,000 S −1 .

16 . The process of claim 2 , wherein one or more of the separating, the extracting of the catalyst, and the extracting of the ions, is at a shear rate of 0.5 to less than 100,000 S −1 .

17 . The process of claim 4 , further comprising increasing a size of an aqueous droplet in the organic phase in a low shear rate coalescer to form a coalesced mixture.

18 . The process of claim 4 , wherein the separated aqueous stream comprises less than or equal to 10 vol % of the organic phase.

19 . The process of claim 4 , wherein the separated organic phase has a viscosity of less than or equal to 100 centipoise.

20 . The process of claim 4 , further comprising determining that the product mixture emulsifies at shear rate of greater than or equal to 150,000 S −1 prior to the separating.

Assignees

• Sabic Global Technologies Bv

Inventors

• Gautam Pankaj Singh
• Kuzeljevic Zeljko
• Hollar William E
• Khadilkar Mohan

Classifications

• C08G64/406 Primary

  Purifying; Drying · CPC title

• C08G64/24

  and phenols · CPC title