GB1330136A - Water-soluble asymmetric 2-1-chromium complex azo dyestuffs and process for their manufacture ice rinks - Google Patents

Abstract

1330136 Chromium complex azo dyestuffs FARBWERKE HOECHST AG 15 Oct 1970 [17 Oct 1969] 49068/70 Heading C4P The invention comprises 2: 1 Cr complex azo dyes having the formula wherein A and C independently represent a phenylene or naphthylene radical which optionally contains, besides X or X<SP>1</SP> one or more substituents selected from SO 3 H, SO 2 NH 2 , -SO 2 -NH alkyl, and -SO 2 N(alkyl) 2 groups, halogen atoms, NO 2 , -CONH 2 , alkyl and alkoxy groups; X and X<SP>1</SP> independently represent -0- or -COO-bound to A and C respectively ortho to the azo bridge; B and D independently represent a radical of the naphthalene, pyrazolone or acetocetic acid arylamide series; Y is -O- or -NH-; Y<SP>1</SP> is -OH, Y and Y<SP>1</SP> being bound to B and D respectively in the ortho position to the azo bridge and in which the -0- atom participating in the Cr complex formation is bonded to the naphthalene nucleus in the 1- or 2- position, the adjacent azo group is bonded accordingly in the 2- or 1- position and the group -N=N-D-Y is bonded in the 6- or 7- position. The dyes may be prepared by reacting either (a) a compound of formula with an equimolar amount of a disazo dye of formula or (b) a compound of formula with an equimolar amount of a monoazo dye of formula in the presence of an acid-binding agent in an aqueous or aqueous-organic medium have a pH of 4.5-9.0 and at a temperature of 50-100‹C. The dyes give grey, navy and brown shades on nitrogen-containing fibres, wool, silk, and synthetic polyamide and polyurethane fibres.