Patent ID: 7425222

Claim:
A process for improving the sun protection factor (SPF) of cellulosic fibre materials selected from cotton and cotton blends, which process comprises contacting said materials with at least one compound of the formula (1) in which M is an alkali metal atom, ammonium or a cation formed from an amine; R 1 and R 1 ′ independently of each other are hydrogen, hydroxy, optionally substituted alkyl, 4-morpholinyl, —NH—R 3 , —N(R 3 ) 2 or —O—R 3 , wherein R 3 is optionally substituted alkyl or optionally substituted aryl, R 2 is a group of formula (2) wherein X is —NH— and R 4 is C 1 -C 4 -alkyl which carries at least one hydrophilic substituent —OM and R 2 ′ has the meaning of R 1 or R 2 , and further contacting said materials with at least one UV absorber of the formula (3) where L 1 and L 2 independently of each other are hydrogen, sulpho, hydroxy, C 1 -C 4 -alkyl or C 1 -C 12 -alkoxy, x and y independently of each other are 1, 2 or 3, X 1 is chloro or fluoro and X 2 is a reactive radical of the formula (4) or (5) wherein Z is a fibre-reactive group and n is 2 or 3 and Y is —CH 2 CH 2 OSO 3 M.