Salt byproduct separation during formation of polyarylene sulfide

Patent metadata

Field	Value
Publication number	US-9938379-B2
Application number	US-201615224884-A
Country	US
Kind code	B2
Filing date	Aug 1, 2016
Priority date	Sep 25, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

First claim

What is claimed is:

1. A system for forming a polyarylene sulfide comprising:
a first polymerization reactor in which a dihaloaromatic compound is capable of being reacted with an alkali metal sulfide or an alkali metal hydrosulfide in an organic amide solvent to form a mixture that includes a polyarylene sulfide and a salt;
a filter unit that is located downstream from the first polymerization reactor and configured to separate the mixture into a filter cake and a filtrate, wherein the filtrate contains at least a portion of the polyarylene sulfide and the filter cake contains at least a portion of the salt; and
a second polymerization reactor located downstream from the filter unit and in which the polyarylene sulfide from the filtrate is capable of being reacted with an alkali metal sulfide or hydrosulfide.

2. The system of claim 1 , further comprising an additional reactor upstream of the filter unit.

3. The system of claim 1 , wherein at least a portion of the filter unit is heated.

4. The system of claim 3 , wherein at least that portion of the filter unit that contacts the mixture and the filtrate is heated.

5. The system of claim 1 , wherein the filter unit is maintained at a pressure that is elevated above atmospheric pressure and at a temperature of from about 220° C. to about 300° C.

6. The system of claim 5 , wherein the elevated pressure is about 300 kilopascals or more.

7. The system of claim 5 , wherein the elevated pressure is constant.

8. The system of claim 1 , wherein the pressure upstream of the filter unit is greater than the pressure downstream of the filter.

9. The method of claim 8 , wherein the downstream pressure is about 300 kilopascals or more.

10. The method of claim 8 , wherein the difference between the upstream pressure and the downstream pressure is constant.

11. The method of claim 8 , wherein the upstream pressure and downstream pressure are constant.

12. The system of claim 1 , further comprising an additional filter unit that is located downstream from the second polymerization reactor.

Assignees

• Ticona Llc

Inventors

• Chiong Hendrich
• Haubs Michael
• Feord Damian
• Shatzer Mark
• Grayson Jacob

Classifications

• C08G75/16 Primary

  by polycondensation of organic compounds with inorganic polysulfides · CPC title

• B01J19/24

  Stationary reactors without moving elements inside (B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02) · CPC title

• C08G75/14 Primary

  Polysulfides · CPC title

• C08J3/203

  Solid polymers with solid and/or liquid additives · CPC title

• B01J19/245

  placed in series · CPC title