A polyester fiber having a superior stainproof property comprises at least one fiber-forming polyester copolymer comprising a backbone polyester polymer and at least one type of terminal substituent which blocks at least some of the terminals of the molecules of the backbone polyester polymer and which substituent consists of a polyoxyalkyleneglycol monoether group of the formula (I):
wherein R' is a monovalent organic radical free from active hydrogen atom, R2 is an alkylene radical, and n is an integer of 2 or more.
一种具有优异防污性能的聚酯纤维包括至少一种成纤聚酯共聚物,该共聚物由主干聚酯聚合物和至少一种末端取代基组成,该末端取代基至少可阻断主干聚酯聚合物分子的部分末端,该取代基由式 (I) 的聚氧亚烷基
乙二醇单醚基团组成:
其中 R'是不含活性氢原子的单价有机基,R2 是亚烷基,n 是 2 或 2 以上的整数。