Cationic dyeable polyester composition as well as preparation method and application thereof

The invention discloses a cationic dyeable polyester composition, which is mainly composed of an aromatic dicarboxylic acid structural unit and an aliphatic dihydric alcohol structural unit, the polyester composition contains a terminal-blocked sulfonate group accounting for 1000-5000 ppm of the total amount of the polyester composition in terms of sulfur element, a common sulfonate group accounting for 200-2000 ppm of the total amount of the polyester composition in terms of sulfur element, and a dimer foreign matter sulfonate compound, and the dimer foreign matter sulfonate compound accounts for 3.0 mol% or less of the terminal-blocked sulfonate group. The polyester composition provided by the invention has the advantages of low insoluble compound content, low-temperature dyeing, good spinnability, little filter pressure rise in the spinning process, long filter screen replacement period and low cost. 本申请公开了一种阳离子可染聚酯组合物，所述聚酯组合物主要由芳香族二元羧酸结构单元和脂肪族二元醇结构单元构成，该聚酯组合物中含有以硫元素计占聚酯组合物总量1000～5000ppm的末端封锁磺酸盐基团、以硫元素计占聚酯