Process for improving the photochemical stability of dyeings and prints on polyester fibres

摘要

A process for the photochemical stabilization of dyeings and prints on polyester fibre material, which comprises treating the polyester fibre material with a compound of formula ##STR1## wherein R. sub.1, R.sub.2, R. sub.3, R.sub.4, n and m are as defined herein.P P The treated dyed or printed polyester fibre material is distinguished by good fastness to light and heat and has a high sun protection factor.