PROCESS FOR CRYSTALLIZING POLYETHYLENE NAPHTHALATE

摘要

PURPOSE: Provided is a process for crystallizing non-crystalline polyethylene naphthalate without fusion generated by adding terephthalic acid, which is used for a pretreatment of a solid state polymerization or a pretreatment of a drying process of the polyethylene naphthalate. CONSTITUTION: The non-crystalline polyethylene naphthalate is crystallized by adding 0.5-10pts.wt. of the terephthalic acid to 100pts.wt. of the non-crystalline polyethylene naphthalate pellets or chips, wherein the crystallization is performed at a temperature of 180-220deg.C. The terephthalic acid is a raw material used in a solid state polymerization of polyethylene terephthalate.