Research on synthesis and application of anti-UV reactive dyes containing a built-in benzotriazol group

Four M-type reactive dyes (yellow, orange, red and blue) containing a built-in 2-(2-hydroxy-5-sulfophenyl)-5-amino-2H-benzotriazol group were synthesized using p-ester and sulphonated p-ester as diazo component, and their structures were identified by MS. Cotton fabrics were dyed with prepared dyes, the reactivity degree and exhaustion degree of dyes were measured, and the dyeing property of yellow dye was worse. Compared with the undyed cotton fabric, the UV transmittance of dyed fabrics has a great decrease. The UPF values of undyed cotton fabric is 1.3, and cotton fabrics dyed with yellow, orange, red and blue dyes are 5.9, 13.7, 18.8, 17.5 respectively, which show good anti-UV properties except yellow dyes. It is also found that the anti-UV property of dark fabrics is better than that of light fabrics.