Burgess, Ryan & Wayne
Highly elastic ionic dye-dyeable polyether-ester block copolymer filaments
 A polyether-ester block copolymer, and filaments formed therefrom, having an enhanced thermal stability of the elastic property thereof and a satisfactory dyeing property, comprises a polymerization product of (A) an acid component comprising as a major ingredient, terephthalic acid, (B) a phosphonium sulfate component comprising a compound of the formula (I): ##STR1## wherein Z.sub.1 =tri- or more valent aromatic or aliphatic group, A.sub.1 =ester-forming group, A.sub.2 =H or ester-forming group, R.sup.1, R.sup.2, R.sup.3, R.sup.4 =alkyl or aryl radical and n=a positive integer, (C) a polymeric glycol component comprising a polyoxyalkylene glycol having an MW of 400 to 6000 and (D) a monomeric glycol component comprising, as a major ingredient, 1,4-butane diol, in which the copolymer component (B) is in an amount of from 0.1 to 5 molar % based on the molar amount of the component (A) and the component (C) is in an amount of from 50 to 80% by weight based on the total weight of the copolymer, and which copolymer has a limiting viscosity number of 1.2 or more, a melting point of 160.degree. C. or more, and a 1/2 crystallization time of 10 seconds or less. 
Teijin Limited
C D C
C08G D01F C08G
inventional inventional inventional
Hironori
Yamada