摘要 |
Polymeric residue including toluene diisocyanate is combined with a solvent having a low affinity for polymer solution and a high affinity for toluene diisocyanate to dissolve toluene diisocyanate leaving the polymeric materials in suspension. The polymeric compounds are precipitated and filtered, the filtrate solution distilled and the toluene diisocyanate recovered as a pure product. |