| 摘要 |
PROBLEM TO BE SOLVED: To provide a normal pressure cationic dyeable polyester which can be cation-dyed under normal pressure and has high strength.SOLUTION: There is provided a normal pressure cationic dyeable polyester that is a polyester of which the main repeating unit is composed of ethylene terephthalate, in which a sulfoisophthalic acid metal salt (A) and a compound (B) such as a sulfoisophthalic acid phosphonium salt are contained in an acid component constituting the polyester so as to simultaneously satisfy two mathematical formulae, and is a copolyester containing 1-20 mol% of at least one type among alkaline metal salts, alkaline earth metal salts, tetraalkylphosphonium hydroxide, tetraalkylammonium hydroxide, and trialkylamine in relation to the total molar weight of the sulfoisophthalic acid metal salt (A) and the compound (B). Preferably, the glass transition temperature of the copolyester is in a range of 70-85°C, and the intrinsic viscosity of the copolyester is in a range of 0.55-1.00 dL/g. In addition, a polyester fiber can be provided by melt spinning of the copolyester. |
