PROCESS FOR PREPARING POLYETHYLENENAPHTHALATE FIBER

摘要

A manufacturing method of a polyethylene naphthalate fiber is provided to the prepolymer with high viscosity and to reduce the difference between the viscosity of the prepolymer and the object viscosity of the final solid polymer. The naphthalene dicarboxylate and the esterification reaction materials of diol are melted and polymerized so that the polyethylene naphthalate pre-polymer with the inherent viscosity of 0.45 to 0.80 dl/g is obtained. The obtained pre-polymer is cut as a chip with a flat shape with the small-sized diameter of below 1.2mm by means of a twin roller in the water with high temperature. The cut pre-polymer chip is polymerized in solid phase. The chip with high viscosity is manufactured by the melting and spinning processes. The melting point of the solid polymer is below 270 degrees centigrade and the density thereof is below 1.350. The distribution of molecular weight is below 1.72.