Process for producing purified polyether sulfones

• US 20030004302A1
• Filed: 05/13/2002
• Published: 01/02/2003
• Est. Priority Date: 05/15/2001
• Status: Abandoned Application

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Okamoto, Satoshi, Saito, Noriaki, Hayashi, Toshiaki
• Application Number:
  US10/142,777
• Publication Number:
  US 20030004302A1
• Time in Patent Office: Days
• US Class Current: 528/373
• CPC Class Codes: C08G 75/23 Polyethersulfones
• CPC Class Codes: C08L 81/06 Polysulfones; Polyethersulfones

Abstract

A process for producing a purified polyether sulfone which comprises bringing a solution of a crude polyether sulfone in an organic solvent in contact with an adsorbent.

Claims

1. A process for producing a purified polyether sulfone which comprises bringing a solution of a crude polyether sulfone in an organic solvent in contact with an adsorbent.

2. The process according to claim 1, wherein the organic solvent is at least one polar solvent selected from the group consisting of sulfoxide solvents, amide solvents, pyrrolidone solvents, piperidone solvents, 2-imidazolinone solvents, diphenyl compounds, hexamethylene sulfoxide, γ

-butyrolactone and sulfolane.

3. The process according to claim 1, wherein the adsorbent is at least one selected from the group consisting of activated carbon, silica gel, silica-alumina complex, activated clay, activated alumina, diatomaceous earth, pearlite, cellulose and asbestos.

4. The process according to claim 1, wherein the crude polyether sulfone is a polymer obtained by polycondensing at least one bisphenol selected from the group consisting of hydroquinone, 4,4′

-biphenol, 2,2-bis(4-hydroxyphenylpropane), 4,4′

-dihydroxydiphenyl ether and 4,4′

-dihydroxydiphenyl sulfone with 4,4′

-dihalodiphenyl sulfone in an organic solvent and in the presence of an alkali metal compound.

5. The process according to claim 4, wherein the alkali metal compound is an anhydrous alkali metal carbonate.

6. A solution of a purified polyether sulfone is an organic solvent obtained by a process according to claim 1.

7. A purified polyether sulfone obtained by removing the solvent from the solution of a purified polyether sulfone in an organic solvent according to claim 6.