Abstract: This invention relates to the use of certain co-solvents in cellulose amine N-oxide solutions, which co-solvents increase the cellulose dissolution rate; lower the temperatures necessary to reasonably form a solution; lower the viscosity of the solution; provide solutions with improved color, amine oxide stability, and cellulose stability, provide a solution with improved flow characteristics; increase solution processability, e.g. wet spinning; permit the replacement of amine oxides by a less expensive co-solvent; and are recoverable and reusable in cellulose dissolution and processing.The co-solvents of the invention comprise compounds, miscible with cellulose-dissolving amine N-oxides, containing primary, or combinations of primary and secondary, amino groups wherein the amino groups are bonded to alkyl, alicyclic, dialkyl ether or alkyl/alicyclic radical(s) and wherein the number of carbon atoms divided by the number of primary amino groups is approximately equal to or less than 4; or#C/#NH.sub.2 .

Abstract: The invention relates to new copolyester polymers which are high molecular weight copolyesters of terephthalic acid, ethylene glycol, dimer acid and polyoxyethylene glycols and to films, fibers and filaments made from these copolyesters. The copolyesters contain about 2 to 4% by weight of dimer acid and about 1 to 3% by weight of polyoxyethylene glycol. Fibers and yarns processed from these copolyesters have markedly improved affinity for disperse dyes.