Patent ID: 9529286
Filing Date: 2016-12-27
CPC Classification: B29C,B29K,B29L,C07C,G03G

Claim Text:
1. A process for making purified bis(4-diethylamino-2-methylphenyl)-(4-diethylaminophenylmethane) comprising: dissolving crude bis(4-diethylamino-2-methylphenyl)-(4-diethylaminophenylmethane) in a first solvent room temperature to form dissolved crude bis(4-diethylamino-2-methylphenyl)-(4-diethylaminophenylmethane); heating a mixture of a second solvent and a third solvent to a temperature of about 50° C. or higher to form a warm co-solvent mixture; adding the dissolved crude bis(4-diethylamino-2-methylphenyl)-(4-diethylaminophenylmethane) to the warm co-solvent mixture in a drop-wise manner to form a precipitate mixture; mixing the precipitate mixture; cooling the precipitate mixture; and drying the precipitate mixture to obtain the dried product comprising purified bis(4-diethylamino-2-methylphenyl)-(4-diethylaminophenylmethane), wherein the first, second and third solvents are not isopropanol.