| 摘要 |
<p>PURPOSE:To obtain the titled precursor free from yarn defects, by washing a polymer containing mainly acrylonitrile in hot water or boiling water with a specific bath ratio to remove impurities, and spinning it. CONSTITUTION:A polymer comprising >=95wt% acrylonitrile and preferably 0.5-3wt% carboxyl group-containing unsaturated monomer (e.g., acrylic acid, etc.) as a flameproofing rate promoting agent is washed with hot water or boiling water with a bath ratio of polymer/water of 1/10-1/20 at >=80 deg.C usually at least for 30min twice, to remove impurities such as a polymerization initiator residue, metal, oligomers with low polymerization degree, etc. The washed polymer is slurried with a solvent such as preferably DMF, etc. containing no metal, dissolved under heating, and spun, to give the aimed precursor.</p> |
