Method for preparing polyarylene sulfide with reduced free iodine content

Patent metadata

Field	Value
Publication number	US-9163119-B2
Application number	US-200913142932-A
Country	US
Kind code	B2
Filing date	Dec 28, 2009
Priority date	Dec 31, 2008
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

The present invention relates to a method for preparing polyarylene sulfide with a reduced free iodine content. More specifically, the method for preparing polyarylene sulfide includes: (a) polymerizing reactants including a diiodo aromatic compound and a sulfur compound to form a polyarylene sulfide; and (b) maintaining the polyarylene sulfide product at 100 to 260° C. for heat-setting. The preparation method of the present invention effectively reduces the free iodine content of the polyarylene sulfide to prevent potential corrosion of facilities for the subsequent process and improves the properties of the polyarylene sulfide product such as thermal stability, so the method can be usefully applied to industrial fields in regard to the preparation of polyarylene sulfide.

First claim

What is claimed is:

1. A method for preparing a heat-set polyarylene sulfide having a melting temperature of 265 to 320° C. and a free iodine content of at most 20 ppm, comprising:
(a) polymerizing reactants including a diiodo aromatic compound, a polymerization inhibitor, and a sulfur compound at an initial temperature of 180° C. to 250° C. and at a final temperature of 270° C. to 350° C. to form a polyarylene sulfide product; and
(b) maintaining the polyarylene sulfide product at 150° C. to 230° C. for heat-setting for 0.5 to 100 hours to give a heat-set polyarylene sulfide;
wherein:
the heat-set polyarylene sulfide has a melting temperature of 265° C. to 320° C. and a free iodine content of at most 20 ppm;
the heat-set polyarylene sulfide has a melting temperature variation of less than 5% before and after the heat-setting step (b); and
the polymerization inhibitor is at least one of N-cyclohexylbenzothiazole-2-sulfenamide, N,N-dicyclohexyl-2-benzothiazole sulfenamide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, and diphenyl disulfide.

2. The method as claimed in claim 1 , wherein the polymerization step (a) is carried out for 1 to 30 hours under an initial condition including a temperature of 180 to 250° C. and a pressure of 50 to 450 torr and then under a final condition including an elevated temperature of 270 to 350° C. and a reduced pressure of 0.001 to 20 torr.

3. The method as claimed in claim 1 , wherein the sulfur compound is solid sulfur.

4. The method as claimed in claim 1 , further comprising:
melt-mixing the diiodo aromatic compound and the sulfur compound prior to the polymerization step (a).

5. The method as claimed in claim 1 , wherein the polyarylene sulfide has a melt viscosity variation of less than 35%.

6. The method as claimed in claim 1 , wherein the polyarylene sulfide has a melt viscosity of 200 to 20,000 poise.

7. The method as claimed in claim 1 , wherein the diiodo aromatic compound includes at least one selected from the group consisting of diiodobenzene, diiodonaphthalene, diiodobiphenyl, diiodobisphenol, and diiodobenzophenone.

8. The method as claimed in claim 1 , wherein the polymerization step (a) is carried out in the presence of a nitrobenzene-based catalyst.

9. The method as claimed in claim 1 , wherein the heat-setting step (b) is carried out in an atmosphere purged with at least one gas selected from the group consisting of nitrogen, air, helium, argon, and water vapor.

10. The method as claimed in claim 1 , wherein the heat-setting step (b) is carried out under vacuum condition.

11. The method of claim 1 , wherein the heat-setting step (b) is carried out for 1 to 40 hours.

Assignees

• Shin Yong-Jun
• Kim Sung-Gi
• Lim Jae-Bong
• Cho Joon-Sang
• Cha Il-Hoon
• Sk Chemicals Co Ltd

Inventors

• Shin Yong-Jun
• Kim Sung-Gi
• Lim Jae-Bong
• Cho Joon-Sang
• Cha Il-Hoon

Classifications

• C08G75/0213 Primary

  containing elements other than carbon, hydrogen or sulfur · CPC title

• C08G75/0268

  using disulfides · CPC title

• C08G75/0263

  using elemental sulfur · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08G75/16 Primary

  by polycondensation of organic compounds with inorganic polysulfides · CPC title