Back to results
US 5,239,106 AGranted
Method of recovering and purifying diphenylcarbonate from phenolic solutions thereof
AssigneeGeneral Electric Company
InventorSheldon J. Shafer
Life of this patent
Estimating the term…
Abstract
Phenolic solutions of 20%-70% by weight of diphenylcarbonate have been found to form a crystalline 1:1 molar adduct of diphenylcarbonate and phenol when allowed to cool to a temperature between about 50.degree. C. and 25.degree. C. Recovery of the crystalline 1:1 molar adduct followed by distillation of phenol therefrom has been found to provide substantially pure diphenylcarbonate.
Claims7
A diphenylcarbonate purification method which comprises,
- (1) forming a crystalline 1:1 molar adduct of diphenylcarbonate and phenol by allowing a liquid phase mixture at a temperature in the range of about 80.degree. C. to 180.degree. C. to cool to a temperature in the range of 50.degree. C. to 25.degree. C., where the liquid phase mixture comprises about 20-70% by weight of diphenylcarbonate and about 80-30% by weight of phenol,
- (2) recovering the crystalline 1:1 molar adduct of (1), and
- (3) heating the crystalline 1:1 molar adduct under reduced pressure to a temperature of up to 180.degree. C. to effect the separation of phenol.
Dependencies are inferred from the claim text.