Patent GB-875888-A (GB)
Title: Disazo dyestuffs containing acid sulphate ester groups and metal complexes thereof
Filed: 1959-01-30
Abstract: The invention comprises disazo dyes of formula:- <FORM:0875888/IV(c)/1> wherein Y is hydrogen or a sulphonic acid group, R2 is the residue of a benzene diazo component, R3 is the same as R2 but having ortho to -N=N- a metal complex-forming group or a group or atom convertible thereto under metallizing conditions, R1 is an ethylene radical, X is hydrogen or an alkali metal cation and m is an integer; and metal complexes thereof.  They are prepared by diazotizing an aminobenzene (R2) and coupling in acid medium with 1-amino- 7-naphthol or a sulphonic acid thereof and then coupling the monoazo compound so obtained with a diazotized aminobenzene (R3) in acid medium, the components being selected so that at least one diazo component contains a -SO2-NH-R1-OSO3X group.  The sulphonamido-ethylene sulphuric acid ester groups may also be introduced into suitable disazo dyestuffs containing sulphonamido-ethanol groups by esterifying with sulphuric acid or by reacting the disazo dyes with chlorosulphonic acid or thionyl chloride to introduce sulphonyl chloride groups, reacting these with ethanolamine and finally esterifying with sulphuric acid. The dyestuffs may be converted in substance or on the fibre into metal (e.g. copper, chromium or cobalt) complexes.  The dyestuffs give black dyeings on hydroxyl- and amidegroup-containing materials and in the case of hydroxyl-group-containing fibres, such as cotton or cellulose, react with the fibre and are fixed by treatment with acid-binding agents.  In Examples: (1) the disazo dye 1-amino- 2-nitro-benzene- 4-sulphonic acid --> 1-amino-7-naphthol \sM 4-chloro- 2-aminophenol-6-sulphonic acid is prepared and treated first with a mixture of chlorosulphonic acid and thionyl chloride to give the sulphochloride, which is then reacted with ethanolamine and the hydroxyethyl-sulphonamide esterified with sulphuric acid; in a modification of the process the sulphochloride is reacted with amino-ethanol-sulphuric acid semi-ester; further dyes are prepared by the above process, the additional components specified being (R2) 3- or 4-nitroaniline and (R3) 6-chloro- or -nitro- 2-aminophenol- 4-sulphonic acid, 2-amino-phenol- 4-sulphonic acid and -4 : 6-disulphonic acid; (2) the disazo dyes 1-amino- 2-nitrobenzene- 4-sulphonyl-aminoethyl hydrogen sulphate --> 1-amino- 7-naphthol \sM 6-chloro- 2-aminophenol- 4-sulphonylaminoethyl-hydrogen sulphate or 1-amino-2-benzoic acid- 5-sulphonylaminoethyl hydrogen sulphate are prepared and coppered; further dyes are prepared by the above process the additional components being (R2) 1-amino- 3-nitrobenzene-4-sulphonylaminoethyl hydrogen sulphate and (R3) 4-chloro- 2-aminophenol- 6-sulphonylaminoethyl hydrogen sulphate and 2-amino-phenol-4-mono- or -4 : 6- di-sulphonylamino-ethyl hydrogen sulphate; (3) the disazo dyestuff 2-nitroaniline --> 1-amino- 7-naphthol- 3-sulphonic acid \sM 2-aminophenol is treated as in (1) to give the hydroxyethyl-sulphonamide, which is chromed or cobalted and the metallized disazo dye esterified with sulphuric acid; (4) the dyestuff 4-nitroaniline --> 1-amino- 7-naphthol- 3-sulphonic acid \sM 4-chloro- 2-aminophenol- 5-sulphonylaminoethyl hydrogen sulphate and 2-nitroaniline-4-sulphonic acid --> 1-amino- 7-naphthol \sM 2-aminophenol -4 : 6-bis sulphonylaminoethyl hydrogen sulphate are prepared. Specifications 637,404, 660,447 and 721,495 are referred to.