| 摘要 |
<p>The compound 2,2-bis(4-hydroxyphenyl) propane is recovered in the form of rhombic crystals from an essentially non-crystalline mixture comprising 2,2-bis(4-hydroxyphenyl) propane, organic by products of the condensation reaction of phenol and acetone, and phenol by lowering the temperature of the mixture from an elevated state to a temperature which is low enough to cause the separation of the phenol and 2,2-bis(4-hydroxyphenyl) propane in equimolar proportions as a crystalline adduct, recovering the adduct, forming a mixture of the adduct and water at an elevated temperature sufficient to completely melt the adduct, and thereafter lowering the temperature of the mixture of water and melted adduct to cause the separation of the 2,2-bis(4-hydroxyphenyl) propane in the form of rhombic crystals substantially free of the phenol. The crystals are easily handled and recovered by means such as filtration or centrifugation, and they can be formed into high quality polycarbonate molding resins. </p> |
