Red monoazo dyes for different number of simple inherit of polyamides and process for their preparation

摘要

1362717 Monoazo dyes CROMPTON & KNOWLES CORP 11 Oct 1971 [12 Oct 1970] 47278/71 Heading C4P New monoazo dyes of formula where M is H, Na, K or NH 4 and R is H, Cl, NO 2 or CH 3 provided that where the benzamide group is positioned para to the azo linkage R is not H, are described. The dyes may be prepared by reacting m- or p-phenylenediamine sulphonic acid with a benzoyl chloride, diazotizing the intermediate amine thus formed and coupling it with 2-amino-8-naphthol-6-sulphonic acid and optionally converting the dye to its Na, K or NH 4 salt by neutralization with an alkali. The dyes give red shades on natural and synthetic polyamide fibre materials and are particularly useful for the differential dyeing of composite nylon yarns and textiles, and may be used alone or with other dyes.