Abstract:
This invention discloses the method of making nylon 6 cationic dyeable whereby the water soluble alkaline metal salts of poly(2methyl-2-((1-oxo-2-propenyl) amino)-1-propanesulfonic acid) are added to caprolactam and the mixture subjected to polymerization conditions.
Abstract:
It has been suggested that a high strength polycaproamide fiber having excess number of carboxyl end groups over amino end groups can be produced by melt spinning a polymer prepared by polymerizing e-caprolactam and reacting the polymer with a dibasic carboxylic acid containing at least six carbon atoms. However, with incorporation of this dicarboxylic acid reactant in continuous operation, serious problems have been encountered in melt-spinning of the polymer due to the frequent occurrence of ''''nubs'''' or enlarged places in the extruded polyamide filament. It has now been found that the occurrence of said nubs in the fiber can be greatly reduced by utilizing certain polyanhydrides of dicarboxylic acid and reacting the polyanhydride at the end of the polymerization. Moreover, dyeing properties of the fiber may be more readily controlled.