PROCESS FOR PURIFYING 2-PHENYL-3, 3 -BIS (4-HYDROXYPHENYL) PHTHALIMIDINE ( PPPBP)

摘要

A method for decoloring 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine ('p,p- PPPBP') is disclosed. The method comprises contacting a liquid solution containing p,p-PPPBP and the common impurities o,p-PPPBP and aminophenone with activated carbon fibers. The activated carbon fibers adsorb the impurities, resulting in a purified solution of p,p-PPPBP. The activated carbon fibers can then be regenerated, such as with a methanol solution having a highly basic pH.