| 摘要 |
<p>An improved copolyester fiber capable of being dyed with cationic dyes and having an excellent brightness, heat resistance and a satisfactory mechanical strength comprises a copolyester resin comprising a polymerization product of at least one aromatic dicarboxylic acid compound, at least one alkylene diol compound and at least one quaternary phosphonium organic sulfonate of the formula (I): <CHEM> wherein A = an aromatic or aliphatic radical, X<1> = H or an ester-forming organic radical, X<2> = an ester-forming organic radical, R<1>, R<2>, R<3> and R<4> = an alkyl or aryl radical, n = 1 or more, and having an [ eta ]f of 0.5 or more, the copolyester fiber having a silk factor of 25 or more and exhibiting the number of scission of backbone chains of the copolyester molecules of 140 x 10<2><3> or less per 10<6> g of fiber when wet heat-treated in a solution of 0.4 g/l of acetic acid in distilled water at 130 DEG C for 60 minutes.</p> |
