Liquid crystalline polyesters having a surprisingly good combination of a low melting point, a high heat distortion temperature, a low melt viscosity, and a high tensile elongation

摘要

Disclosed is a select class of liquid crystalline polyesters and molding compositions comprising the polyesters and glass fiber. The liquid crystalline polyesters consist essentially of (1) diacid residues consisting essentially of (i) cyclohexanedicarboxylic acid residues and (ii) other diacid residues selected from terephthalic acid residues, 2,6-naphthalene-dicarboxylic acid residues, or a mixture thereof; (2) diol residues consisting essentially of hydroquinone residues, 4,4'-biphenol residues or a mixture thereof; and, optionally, (3) p-hydroxybenzoic acid residues. In the above definition, the moles of diol residues are equal to the moles of diacid residues and the total of the (1), (2) and (3) mole percentages is equal to 100. The liquid crystalline polyesters have melting points determined by differential scanning calorimetry equal to or less than 360° C.