HIGH-VISCOSITY POLYETHYLENE NAPHTHALATE RESIN, ITS PRODUCTION AND MOLDING PRODUCT COMPRISING THE RESIN

摘要

PROBLEM TO BE SOLVED: To obtain a polyethylene naphthalate resin not raising a melting point in part of the resin even by a high-temperature solid-phase polymerization, having excellent productivity and color tone of resin. SOLUTION: This polyethylene naphthalate resin comprises 2,6- naphthalenedicarboxylic acid as a main acid component and ethylene glycol as a main glycol component and has 0.65-1.2 intrinsic viscosity. When the resin is heated from 25 deg.C at 10 deg.C/minute by a scanning calorimeter, the peak temperature of an initially observed endothermic temperature is >=245 deg.C. When dissolved in a mixed solvent of phenol/1,1,2,2-tetrachloroethane of 60/40 (weight ratio) in 1 g/deciliter concentration at 130 deg.C, the resin is dissolved within two hours.