Purification of diphenyl terephthalate

摘要

Diphenyl phthalates are purified by crystallizing them from dipolar- aprotic solvents or solutions of solvents containing such solvents. The phthalate solutions are advantageously, but not necessarily, treated in a carbon column in hydrocarbon solvent without dipolar- aprotic solvents present to remove part of the color and impurities, and then dipolar- aprotic solvents are added to the solution before crystallization to aid in the final removal of color and impurities.