Process for preparing wetfast polyamide fibers

A process for preparing a wetfast dyed polyamide fiber comprising the steps of

• (a) presenting to a dyebath a fiber which is formed of a polyamide polymer having a high amino end group content which is comprised of the polyamide polymerization reaction product of polyamide-forming monomers in the presence of between about 0.50 to about 0.80 weight percent of a hindered piperidine derivative and between about 0.05 to about 0.40 weight percent of a carboxylic acid chain regulator sufficient to form a polyamide polymer having at least about 65 percent amino end groups comprised of secondary or tertiary amines;
• and
• (b) in the dyebath, dyeing the polyamide fiber with one or more dyestuffs to obtain a dyed polyamide fiber which exhibits better wetfast properties, including improved resistance to dye bleeding in water and improved colorfastness to laundering, as compared to a fiber formed of a polyamide polymer having a content of secondary or tertiary amino end groups of less than about 65 percent.