Process for coloring polytrimethylene terephthalate fibres and use of the fibres colored by this process

Abstract

The present invention relates to a process for coloring polytrimethylene terephthalate fibers by treating the fibers with an aqueous liquor containing at least one dispersing colorant, in the absence of a carrier and the application of pressure. The temperature of the treatment is carried out at or below the boiling point of the liquid, within 20.degree. C. of the boiling point of the liquor. The coloring process begins at a liquor temperature between 20.degree. and 50.degree. C., and the temperature is raised over a period of 20 to 90 minutes. The liquor is then cooled to a temperature between 20.degree. and 50.degree. C., preferably at a rate of cooling of 1.degree. C. per minute, so that at least 95% wt. % of the colorant is absorbed by the fibers, and the dispersing colorant penetrates the fibers to a relative depth of at least 5% with respect to the diameter of the fibers.

Dependencies are inferred from the claim text.