Use of substituted 2-(2'-hydroxyaryl)-2H-benzotriazolesulfonates as photostabilizing agents for natural and synthetic fibres

Abstract

A method for protecting synthetic and natural fibres against phototendering. The method comprises treating the fibres with a substituted benzotriazolesulfonate of the following formula: ##STR1## wherein (I) R.sub.1 is hydrogen or halogen, R.sub.2 is hydrogen or alkyl, R.sub.3 is hydrogen or hydroxy, R.sub.4 is --SO.sub.3 X where X is hydrogen or an alkali metal, and R.sub.5 is hydrogen, with the proviso that R.sub.2 is not methyl when R.sub.1 and R.sub.3 are hydrogen; or (II) R.sub.1, R.sub.3 and R.sub.4 are hydrogen, R.sub.2 is --SO.sub.3 X where X is hydrogen or an alkali metal, and R.sub.5 is --OR.sub.6 where R.sub.6 is hydrogen or alkyl; or (III) R.sub.1 is hydrogen or halogen, R.sub.2 is --SO.sub.3 X where X is hydrogen or an alkali metal, R.sub.3 and R.sub.5 are hydrogen, and R.sub.4 is hydrogen, alkyl or benzyl; or (IV) R.sub.1 is --SO.sub.3 X where X is hydrogen or an alkali metal, R.sub.2 is alkyl, R.sub.3 and R.sub.5 are hydrogen, and R.sub.4 is hydrogen or alkyl; under acidic conditions. The method is particularly suitable for treating wool, silk and nylon fibres, including blends thereof.

Dependencies are inferred from the claim text.