| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique of inhibiting adherent staining caused in facilities to a minimum to enable economical distillation and purification in reutilizing the unreacted monomer content formed in the process for producing PAN-based fibers by solution polymerization using an aprotic polar solvent and a radical initiator. <P>SOLUTION: A method of reutilizing the unreacted monomer content in the polymerization of acrylonitrile (AN) includes a step of performing azeotropy of water and AN, a step of separating a distillate of the azeotropy into an aqueous phase and an organic phase by decantation to recover crude AN including not less than 90 wt.% AN, a step of subjecting the crude AN to reduced-pressure distillation at least once in the presence of a polymerization solvent and a polymerization inhibitor in a distillation column, and a step of recovering highly purified AN having a purity of 97 wt.% or higher, and a step of adding at least part of the purified AN to the polymerization step as a polymerization raw material in separating the unreacted monomer content from an aqueous coagulation bath solution after spinning polyacrylonitrile (PAN). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
