Disazo pigments containing naphthalene coupling components

Abstract

Disazo pigments of the formula ##STR1## wherein R.sub.1 is 2-nitro-5-chlorophenyl or 1-nitronaphthyl-2, R.sub.2 is naphthalene in which the azo, hydroxyl and --CO--group are in the 1,2,3-position and R.sub.4 is a phenylene or naphthalene group are prepared. The disazo pigments may be used for pigmenting high molecular organic materials such as cellulose ethers, polyamides, polyurethanes and acrylic. The pigments have very good fastness to migration, heat and to light.

Dependencies are inferred from the claim text.