Title:
METHOD FOR CONTINUOUSLY RECOVERING DIMETHYLFORMAMIDE FROM WASTE SOLUTION RESULTING FROM PRODUCTION OF POLYIMIDE
Document Type and Number:
WIPO Patent Application WO/2023/014050
Kind Code:
A1
Abstract:
The present invention relates to a method for efficiently recovering dimethylformamide at high purity from a waste solution resulting from the production of a polyimide. The method according to the present invention is directed to a method for recovering dimethylformamide from a waste solution, which results from the production of a polyimide and contains the dimethylformamide, acetic acid, catalysts, water, and solid particles, the method comprising: (a) a neutralization step of adding a metal hydroxide to the filtered waste solution to make the acetic acid into a non-volatile acetate; (b) a first distillation step of removing water contained in the waste solution undergoing step (b); (c) a second distillation step of separating and removing the non-volatile acetate from the waste solution; (d) a water content adjustment step of adding water to the waste solution distilled in step (c) to adjust the water content in the waste solution, so that the dimethylformamide and the catalyst contained in the waste solution are not an azeotropic mixture; and (e) a third distillation step of separating and recovering, through fractional distillation, dimethylformamide from the waste solution with the adjusted water content.
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Inventors:
HWANG SUN SUB (KR)
KIM SEOK JUNG (KR)
HWANG BAEK GYU (KR)
KIM YONG HYUN (KR)
KIM SEOK JUNG (KR)
HWANG BAEK GYU (KR)
KIM YONG HYUN (KR)
Application Number:
PCT/KR2022/011402
Publication Date:
February 09, 2023
Filing Date:
August 02, 2022
Export Citation:
Assignee:
GTCNS CO LTD (KR)
International Classes:
C07C231/24; B01D1/06; B01D1/22; B01D3/14; B01D35/02; C07C231/12; C07C233/03; C08G73/10; C08G85/00; C08J11/02
Foreign References:
| KR101986367B1 | 2019-06-05 | |||
| KR20190064299A | 2019-06-10 | |||
| KR20030018474A | 2003-03-06 | |||
| JP2002363150A | 2002-12-18 | |||
| KR20130101279A | 2013-09-13 |
Attorney, Agent or Firm:
IAM PATENT FIRM (KR)
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