PURPOSE: In interfacial polymerization, to obtain a polyester having improved heat resistance and molding properties in high reproducibility, by bringing an alkali aqueous solution of a bisphenol into contact with a solution of an acid chloride in an organic solvent with vigorous stirring in a short time so that the solutions are dispersed rapidly and uniformly.
CONSTITUTION: In subjecting a solution of a dicarboxylic acid dihalide shown by the formula I (carbonyl is in m-position and p-position each other; X is halogen) in an organic solvent and an alkali aqueous solution of bisphenol shown by the formula II (OH is in m-position or p-position based on -SO2-) and shown by the formula III (OH is in m-position or p-position based on Y; Y is 1W20C bifunctional hydrocarbon, -O-, etc.; a is 0, or 1; R1W4 are H, or 1W8C hydrocarbon or halogen; when Y is -SO2- and a is L, R1WR4 are not H simultaneously) to interfacial polymerization in a ratio of 0.36W1.06mol of the bisphenol shown by the formula II and 0.04W0.66mol of the bisphenol shown by the formula III based on 1mol of the dihalide (total amount of both the bisphenols is 0.90W1.10mol), polymerization is carried out with vigorous stirring in such a way that the polymerization time tc and the addition time ta satisfy the relationship shown by the equation 0<ta≤1/5tc.
KAWAMATA MOTOO
TSUBOI HIKOTADA
SONOBE YOSHIO
HASHIMOTO MITSUYOSHI
