PURPOSE: To provide a liquid-crystalline polyesteramide comprising p- aminobenzoic acid units, aromatic diol units, 2,6-naphthalenedicarboxylic acid units, and p-hydroxybenzoic acid units, having a high elastic modulus and a high strength, high in soldering heat resistance, and useful for injection moldings, etc.
CONSTITUTION: p-Aminobenzoic acid, methylhydroquinone, 2,6-naphthalene dicarboxylic acid, and p-hydroxybenzoic acid are fed into a reactor equipped with a stirring blade, a nitrogen gas-introducing port, and a pressure-reducing port, subjected to the replacement of gases in the reactor with nitrogen gas and the feed of acetic anhydride into the reactor, acetylated at 140°C for a hour, heated up to 320°C, and subsequently polymerized under vacuum to obtain the objective liquid-crystalline polyesteramide comprising (A) 5-22mol.% of p-aminobenzoic acid units of formula I, (B) 10-30mol.% of aromatic diol units of formula II [Ar1 is group of formula III (R is 1-6C alkyl, etc.; m is 1, 2; n is 1-4)], (C) 10-30mol.% of 2,6-naphthalenedicarboxylic acid units of formula IV, and (D) 30-65mol.% of p-hydroxybenzoic acid units of formula V.
KIMURA MASATOSHI
HONMA MASARU
TOKUNAGA TOMOHIKO
