THE METHOD OF REDUCTION OF SOLID POLYMERIZATION REACTION TIME OF POLYETHYLENETEREPHTHALATE

摘要

A manufacturing method of a polyethylene-terephthalate for reducing the solid polymerization reaction time is provided to increase the viscosity of pre-polymer maximally and to cut the pre-polymer as a flat type chip by means of a twin roller. An esterification reacting product by the terephthalic acid and diol is melted and polymerized so that the polyethylene terephthalate pre-polymer with the inherent viscosity of 0.45-0.80 dl/g is obtained. The obtained pre-polymer is cut by means of a twin roller in the hot water so that the flat chip with a thin diameter of below 1.2 mm is obtained. The cut pre-polymer chip is dried under the hot wind of 100 to 160°C and vacuum for two hours or more. Thereafter, the temperature is raised until 230 to 260°C within four hours and then the solid polymerization is performed for 5 to 12 hours in the vacuum state, so that the polyethylene terephthalate chip with the high inherent viscosity of above 0.80 dl/g is obtained. The polyethylene terephthalate solid polymer is spun and drawn at the low temperature of below 310°C as the temperature of a spinning extruder.