Patent GB-349600-A (GB)
Title: The manufacture of black azo-dyestuffs
IPC: C09B35/50
Filed: 1930-02-24
Abstract: Azo dyes; substantive dyes, dyeing with.-Azo dyes are obtained by coupling with 1 mol. of a 1 : 8-aminonaphthol mono- or di-sulphonic acid 2 mols. of diazotized nitro- or acylamino-amines of the benzene series of which at least one carries a hydroxy, carboxy, or ether group in o-position to either of the nitrogenous groups, converting the nitro and acylamino into amino groups by reduction and saponification respectively, tetrazotizing, and coupling with 2 mols. of components each carrying two auxochrome groups in m-position to each other.  Specified auxochrome groups are amino, alkylamino, and hydroxy groups.  The products are distinguished from the dyestuffs of similar constitution described in Specifications 7969/95, 14483/95, 2196/96, 18977/99, [all in Class 2, Acids and salts, Organic &c.], and 267,633, [Class 2 (iii), Dyes &c.], by the improved fastness to light of their dyeings when after-treated with an aldehyde and a copper salt. The following examples are specified.  (1) The nitro groups of the dyestuff 5-nitro-2-aminoanisol --> (acid) 1 : 8-aminonaphthol - 4 : 6 - disulphonic acid (K-acid) (alkaline) \sM 5 - nitro-2-aminoanisol are reduced with sodium sulphide, and the diaminodisazo product is tetrazotized and coupled (alkaline) with 2 mols. of m-aminophenol; the product gives on vegetable fibres reddish black dyeings which become greener and faster to light on after-treatment with formaldehyde and copper sulphate.  (2) The diaminodisazo product in (1) is tetrazotized and coupled with 1 mol. of m-phenylenediamine and 1 mol. of resorcinol; the product gives on vegetable fibres reddish black dyeings which become greener and faster to light on after-treatment with formaldehyde and copper sulphate or with acetaldehyde and copper acetate.  (3) The nitro groups of the dyestuff 5-nitro-4-methyl-2-aminoanisol --> (acid) K-acid (alkaline) \sM 5-nitro-4-methyl-2-aminoanisol are reduced and the diaminodisazo product is tetrazotized and coupled with 2 mols. of resorcinol; the product gives on cotton black dyeings which become bluer and faster to light on after-treatment with formaldehyde and copper salts; similar products are obtained when the resorcinol is replaced by 2 : 4 : 41-triaminodiphenyl, m-phenylenediamine, m-toluylenediamine, 2 : 4-diaminoanisol, 2 : 4-diaminodiphenylamine, 2 : 4-diaminodiphenylether-41-sulphonic acid, 3-diethylaminophenol, or 3-aminophenylglycine.  (4) The nitro groups of the dyestuff 4-nitraniline --> (acid) K-acid (alkaline) \sM 5-nitro-2-aminoanisol are reduced and the diamino disazo product is tetrazotized and coupled with 2 mols. of m-phenylenediamine; the product gives on cotton black dyeings which become greener and faster to light on after-treatment with formaldehyde and copper salts; similar products are obtained when the K-acid is replaced by 1 : 8-aminonaphthol-3 : 6-disulphonic acid (H-acid) or by 1 : 8 : 4-aminonaphtholsulphonic acid, or when as diazo components are used two of the following, viz. 5-nitro-2-aminobenzoic acid, 5-nitro-2-aminophenol, 5-nitro-2-aminophenetol, 4-nitro-2-aminoanisol, 5-nitro-4-chloro-2-aminoanisol, 2-chloro-4-nitraniline, 2 : 6-dichloro-4-nitraniline, 2-methyl-4-nitraniline, or sulphonic acids thereof, providing that at least one of the diazo components carries an alkoxy, hydroxy, or carboxylic group.  (5) The dyestuff 4-aminoacetanilide --> (acid) H-acid (alkaline) \sM 5-nitro-4-methyl-2-aminoanisol is subjected to saponification and reduction of the nitro group, and the diaminodisazo product is tetrazotized and coupled with 2 mols. of resorcinol; the product gives on vegetable fibres full black shades which become faster to light on after-treatment with formaldehyde and copper salts; the same product is obtained when the 4-aminoacetanilide is replaced by 4-nitraniline, the saponification omitted, and both nitro groups reduced.  (6) The acetylamino groups of the dyestuff 2-acetylamino-5-aminoanisol --> (acid) K-acid (alkaline) \sM 4-aminoacetanilide are converted by saponification into amino groups, and the diaminodisazo product is tetrazotized and coupled with 1 mol. of m-phenylenediamine and 1 mol. of resorcinol; the product gives on vegetable fibres full black dyeings which become bluer and faster to light on after-treatment with formaldehyde and copper salts; a similar product is obtained when the 2-acetylamino-5-aminoanisol is replaced by 4-acetylamino-2 : 5-dimethoxyaniline.  (7) On replacing the 4-aminoacetanilide in (6) by 2-acetylamino-4-chloro-5-aminoanisol, the product gives dyeings which on after-treatment with formaldehyde and copper salts are bluish black and very fast to washing and light.  (8) The acetylamino groups of the dyestuff 2-acetylamino-5-aminoanisol --> (acid) 1 : 8 : 4 - aminonaphtholsulphonic acid (alkaline) \sM 2-acetylamino-5-aminoanisol are converted by saponification into amino groups, and the diaminodisazo product is tetrazotized and coupled with 2 mols. of resorcinol; the product gives on cotton full black dyeings which become faster to light on after-treatment with formaldehyde and copper salts.  (9) The nitro groups of the dyestuff 4-nitraniline --> (acid) K-acid alkaline) \sM 5-nitro-2-aminophenol are reduced, and the diaminodisazo product is tetrazotized and coupled (alkaline) with 2 mols. of m-aminophenol; the product gives on cotton black dyeings which become faster to light on after-treatment with formaldehyde and copper salts.  (10) On replacing the 5-nitro-2-aminophenol in (9) by 5-nitro-2-aminobenzoic acid a similar product is obtained.