Photochemically stable dyed cellulosic or polyamide textiles - obtd. by treating dyed material with a catalytically crosslinkable N-methylol-urea or N-methylol-melamine cpd.

摘要

A process for producing coloured cellulose or polyamide fibre materials (I) which are stable to photochromism, by treating the dyed material with a N-methylol-urea or N-methylol-melamine cpd. (II) which is crosslinked by heating in the presence of catalysts. Also claimed is a process for determining photochromism, by exposing part of the textile sample to light and keeping the other part covered, testing both parts by colorimetry, keeping the sample in the dark for at least 48 hrs. and repeating the colorimetric measurements; photochromism is calculated from the difference between the first two measurements, allowing for any correction due to the second measurements. USE/ADVANTAGE - Crosslinkable cpds. (II) are useful for treating (I) to increase their stability to photochromism (claimed). The process provides a means of preventing colour change in dyed textiles when exposed to light (esp. preventing the formation of green or brown colours with yellow and orange azo dyes