发明名称 |
Process for recovering N-methylpyrrolidone by plural distillations |
摘要 |
A process for recovering N-methylpyrrolidone contained in an N-methylpyrrolidone-containing liquid formed in the process for preparing a polyarylene thioether by the dehalogenosulfidation of a dihalogeno-aromatic compound and an alkali metal sulfide in the presence of N-methylpyrrolidone as the polymerization solvent, which comprises (a) subjecting the N-methylpyrrolidone-containing liquid to distillation to distill and recover the majority of contained N-methylpyrrolidone while recovering a distillation residue having such a flowability that flow transferring of the distillation residue is possible, and (b) supplying the distillation residue to an air-tight mixer for a highly-viscous fluid, which has a vent and is provided with a heater, to treat the distillation residue under the conditions of a temperature in the mixer of 190 DEG to 310 DEG C., a pressure in the mixer of 50 to 760 Torr and a residence time in the mixer of 5 minutes to 10 hours, thereby to distill N-methylpyrrolidone contained in the distillation residue through said vent, the distilled N-methylpyrrolidone being collected. According to this process, N-methylpyrrolidone can be recovered at a high recovery without deterioration of the N-methylpyrrolidone.
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申请公布号 |
US4976825(A) |
申请公布日期 |
1990.12.11 |
申请号 |
US19890372221 |
申请日期 |
1989.06.23 |
申请人 |
KUREHA KAGAKU KOGYO KABUSHIKI KAISHA |
发明人 |
IWASAKI, TAKAO;HORIKOSHI, KATSUMI;YOSHIJI, YUZO |
分类号 |
C07D207/263;C07D207/26;C07D207/267;C08G75/02;C08G75/06 |
主分类号 |
C07D207/263 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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