Purification of polymer solution

• US 4,177,343 A
• Filed: 12/19/1977
• Issued: 12/04/1979
• Est. Priority Date: 12/19/1977
• Status: Expired due to Term

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Pannell, Calvin E.
• Primary Examiner(s): Briggs, Sr., Wilbert J.
• Application Number:
  US05/861,610
• Time in Patent Office: 715 Days
• Field of Search: 260/47 XA, 528/196, 528/197, 528/482
• US Class Current: 528/482
• CPC Class Codes: C08G 64/406 Purifying; Drying

Abstract

Undesired impurities in polymer solutions, such as amine scavenging agents or hydrochloric acid, are removed by passing a contaminated polymer solution through a strong acid cation exchange resin bed.

Claims

1. A method of removing organic contaminants from a non-aqueous polycarbonate polymer solution containing the same which comprises contacting said polymer solution with a strong acid cation exchange resin effective to remove said contaminants therefrom, and thereafter recovering a purified polymer solution.

2. The method of claim 1 wherein substantially all of the contaminants are removed from the polymer solution.

3. The method of claim 1 wherein the contaminant is pyridine hydrochloride.

4. The method of claim 3 wherein substantially all of the contaminant is removed from the polymer solution.

5. The method of claim 1 wherein the polymer solution comprises a phenolphthalein polycarbonate polymer in a solvent and the contaminant is pyridine hydrochloride.

6. The method of claim 5 wherein substantially all of the contaminant is removed.

7. The method of claim 1 wherein the resin is a macroporous strong acid cation exchange resin.

8. The method of claim 5 wherein the resin is a macroporous strong acid cation exchange resin.