| 摘要 |
Bis-beta-hydroxyethyl terephthalate is purified by dissolving crude bis-beta-hydroxyethyl terephthalate in a hot solvent comprising ethylene dichloride, s-tetrachloroethane, or 1,2-propylene dichloride, or mixtures thereof, removing suspended matter from the solution, cooling and allowing the bis-betahydroxyethyl terephthalate to crystallize, and removing the crystallized material from the solvent. When the crude material is dark in colour, the hot solution may be treated with decolourizing charcoal before cooling to crystallize the product. |
