NORMAL-PRESSURE CATION-DYEABLE POLYESTER COMPOSITION AND FIBER

摘要

PROBLEM TO BE SOLVED: To provide a normal-pressure cation-dyeable polyester fiber which can be cation-dyed under normal pressure and has high strength.SOLUTION: A polyester composition contains: polyester comprising the ethylene terephthalate accounting for 80 mol% of all repeating units thereof; and an inactive particle. An acid component constituting the polyester contains metal salt (A) of sulfoisophthalic acid and a compound (B) being phosphonium salt of the sulfoisophthalic acid in such a state that two numerical expressions are satisfied simultaneously. The inactive particle accounts for 0.1-5.0 wt.% of the weight of the polyester composition and contains an antimony compound and at least one selected from calcium carbonate and the like.