HIGHLY HEAT-RESISTANT POLYESTER FIBER MATERIAL, TIRE CORD, DIPPED CORD, AND METHOD FOR PRODUCING HIGHLY HEAT-RESISTANT POLYESTER FIBER MATERIAL

摘要

Disclosed is a highly heat-resistant polyester fiber material which is capable of maintaining mechanical characteristics at high temperatures, particularly at a temperature not less than the melting point of the polyester. Also disclosed are a tire cord, a dipped cord and a method for producing a highly heat-resistant polyester fiber material. Specifically disclosed is a highly heat-resistant polyester fiber material which is composed of a polyester fiber containing an ethylene terephthalate unit as a main repeating unit and satisfies the conditions (a) and (b) below at the same time in a dynamic viscoelasticity measurement. (a) Storage modulus at 275˚C (E') ≥ 0.1 MPa (b) Main dispersion peak temperature of loss tangent (tan δ) ≤ 148˚C