Patent ID: 8592548
Filing Date: 2013-11-26
Classification: C07D,C08G

Abstract:
1. A method for preparing a bis(halophthalimide), said method comprising sequentially: (A) preparing a mixture comprising at least one halophthalic anhydride and at least one solvent wherein the mixture has a temperature greater than 150° C., (B) adding to the mixture formed in step (A) at least one molten diamine to form a reaction mixture, said reaction mixture being characterized by “an initial molar ratio of halophthalic anhydride to diamine”, wherein the at least one molten diamine has the formula H (C) heating the reaction mixture formed in step (B) to a temperature of at least 150° C., and removing water of imidization; (D) analyzing the reaction mixture formed by the combination of steps (A)-(C) to determine the initial molar ratio of halophthalic anhydride to diamine; and (E) adding anhydride or diamine to the mixture formed by the combination of steps (A)-(C) to achieve a “corrected molar ratio” of halophthalic anhydride to diamine, said initial molar ratio and corrected molar ratio being in a range between about 2.01 and about 2.3, and (F) adding sodium phenyl phosphinate imidization catalyst to the mixture and heating to a temperature of at least 100° C., to obtain a bis(halophthalimide) product mixture that is substantially free of water.