GB776873A - Manganese salts of chromium complexes of monoazo dyestuffs and their use in lacquers - Google Patents

Abstract

Manganese salts of chromium complexes of 1 - (51 - chloro - 21 - carboxyphenylazo) - 2-naphthol - 3 - carboxylic acid which contain 0.4-0.6, preferably 0.5, atoms of metal per mol. of dyestuff (see Group IV (c)), are used as maroon pigments in nitrocellulose lacquers. Other constitutents of the lacquers may be metal powders, e.g. aluminium powder, synthetic resins, other cellulose derivatives and solvents or diluents such as dibutylphthalate, xylene, toluene, ethyl and butyl acetates and butanol. In examples, lacquers are made from (2) the pigment, nitrocellulose, an oil-modified alkyd resin and the above listed solvents and diluents; and (3) the same constituents as (2) with the addition of aluminium paste.ALSO:The invention comprises manganese salts of chromium complexes of 1 - (51 - chloro - 21 - carboxyphenylazo) - 2 - naphthol - 3 - carboxylic acid which contain 0.4 to 0.6, preferably 0.5, atoms of metal per mol of dyestuff. They may be made by treating the chromium complex with a manganese salt such as the chloride or sulphate. The monoazo dyestuff is made by coupling diazotized 4 - chloro - 2 - aminobenzoic acid with 2, 3 - hydroxy - naphthoic acid in an alkaline medium and the dyestuff is chromed by conventional methods. The manganese salts are pigments and may be used in lacquers vide Group IV(a). An example is provided of the preparation of a manganese salt of the chromed dyestuff.