method for the preparation of metaalbevattende polyazokleurstoffen analogues in a normal way for dyeing or printing of leather with these colours,and the resulting objects of dyed or printed leather.

摘要

1313382 Polyazo dye; metal complexes SANDOZ Ltd 24 July 1970 [7 Aug 1969] 36017/70 Heading C4P Metallized polyazo dyes have the formula wherein R-R 3 represent hydrogen, halogen, nitro, substituted or unsubstituted alkyl or alkoxy, COOH or -SO 3 H; R 4 represents the radical or the radical of a freely selected diazo component; Me is a metal atom and n is 0, 1 or 2. The dyes may be prepared by coupling, in any order, 2 moles of the monoazo dye of formula with 1 mole of a diazo compound of an amine of formula and 0, 1 or 2 moles of a diazo compound of an amine of formula R 4 -NH 2 and treating the resulting azo compound with a metal complexing agent. Alternatively 1 mole of the metal complex of formula may be coupled with 1 mole and 0, 1 or 2 of the diazo components indicated above. Preferred metals are Fe, Co, and Cr and the integer n is preferably 0 or 1. The dyes are used for dyeing leather.