Patent ID: 7304121

Claim:
A liquid-crystalline polyester obtainable by a method comprising the steps of: preparing a prepolymer consisting of the repeating units represented by formulae (I), (II), (III) and (IV): wherein, p, q, r and s represent relative molar proportions (mol %) of the repeating units in the liquid-crystalline polyester resin and satisfy the following formulae: 60 ≦p≦ 80 10 ≦r≦ 20 10 ≦q+s≦ 20 0.05 ≦s /( q+s )≦0.3 p+q+r+s= 100; and heating the prepolymer in solid state at 250-350° C., provided that the liquid crystalline polyester has a deflection temperature under load of 280-340° C., and a melt viscosity of 10-60 Pa·s, wherein the melt viscosity is determined at a temperature 30° C. higher than the crystalline melting temperature of the resin, which is determined by differential scanning calorimetry, and a shear rate of 1000 sec-1.