Process for improving the sun protection factor of cellulosic fibre material

摘要

A process for improving the sun protection factor (SPF) of cellulosic fibre materials and blends thereof, which comprises contacting said materials with at least one compound of the formula (1) in which M is hydrogen, an alkali metal atom, ammonium or a cation formed from an amine; R₁ and R₁' independently of each other are -NH-R₃, -N(R₃)₂ or -O-R₃, wherein R₃ is aryl substituted by -CO-X-R₅, wherein X is O or NH and R₅ is optionally substituted C₁-C₄-alkyl, R₂ is a group of formula -O-R₄ wherein R₄ is hydroxy alkyl, alkoxy alkyl or hydroxy alkoxy alkyl, and R₂' has the meaning of R₁ or R₂.