| abstract |
Modified polyester filaments having over conventional filaments, improved inherent thermal stability in the presence of oxygen and inherent disperse dye uptake, without the significant loss in dye lightfastness typical of such modified filaments, are produced from terephthalic acid; glycols; small amounts of mixtures of compounds having a typical general formula: R-O(G-O)x-H, where R is an alkyl group containing an average of from about eight to 20 carbon atoms; G is a hydrocarbon radical selected from the group consisting of ethylene, propylene, and isomers thereof, butylene and isomers thereof, and mixtures of the above; and x has an average value of from 8-20, and is about equal to 8-greater than R; and small amounts of manganous ion. Polyfunctional chainbranching agents in amounts up to about 0.7 mole percent, based on the weight of the dicarboxylic acid or ester-forming derivative thereof, may be added, whereby the polymer, with the chain terminators described above, can be polymerized to higher molecular weights by ordinary polymerization techniques. |