Patent GB-432355-A (GB)
Title: New azo dyestuffs and their application in leather dyeing
IPC: C09B35/00
Filed: 1934-01-20
Abstract: Dis-, tris-, and tetrakisazo dyes are made from tetrazotized benzidine-2 : 2<1>-disulphonic acid or the tetrazo compound of the tolidine disulphonic obtained from o-nitrotoluene by sulphonation, alkaline reduction and intramolecular change of the hydrazo compound (1) by coupling with 2 mols. of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol or with 1 mol. of such an acid and 1 mol. of another such aminonaphthol sulphonic acid; (2) by coupling with 1 mol. of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol and 1 mol. of a - or b -naphthol or a sulphonic acid thereof, resorcinol, resorcylic acid 1 : 3 : 4, b -oxynaphthoic acid, salicylic acid, o-cresotinic acid, phenol, cresols, phenylpyrazolones, or an aminophenolic or amino component, e.g. m-phenylene or m-tolulylene diamine; (3) by coupling with 2 mols. of an acyl derivative of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol containing an acyl group derived from a fatty acid of eight or less carbon atoms or from a substituted or unsubstituted aromatic acid; (4) by coupling with 1 mol. of an acylaminonaphthol sulphonic acid as defined in (3) and 1 mol. of the second components stated in (2); (5) by coupling with 2 mols. of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol one or both of which have been previously coupled with a diazo compound, or alternatively by coupling the tetrazo compound with 2 mols. of the said aminonaphthol sulpho acid and subsequently coupling with 1 or 2 mols. of the diazo compound; (6) by coupling with one molecule of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol which is previously or subsequently coupled with a diazo compound, the second diazo group of the tetrazo compound being coupled with one of the second components in (2); (7) by coupling in alkaline solution with either one or two mols. of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol, the product rediazotized and coupled with 2 mols. of one of the second components of (2); (8) by coupling with either 1 or 2 mols. of a middle component other than 2 : 5- or 1 : 8-aminonaphthol sulphonic acid, the product rediazotized and coupled with 2 mols. of a sulphonic acid of 2 : 5- or 1 : 8-aminonaphthol.  They are suitable for leather dyeing.  Suitable acids specified are J, H and K acids.  In examples, the following dyes are described: (1) and (4) benzidine-2 : 2<1>-disulphonic acid \sQ (alkaline) H acid or J acid; (2) and (8) benzidine-2 : 2<1>-disulphonic acid or the tolidine disulphonic acid \sQ (alkaline) acetyl H acid; (3) 1-phenyl-3-methyl-5-pyrazolone \sM benzidine-2 : 2<1>-disulphonic acid --> (acid) H acid \sM (alkaline) p-nitraniline; (5) and (9) benzidine-2 : 2<1>-disulphonic acid or the tolidine-disulphonic acid \sQ (alkaline) H acid \sx (acid) p-nitraniline; (6) H acid \sM (acid) benzidine-2 : 2<1>-disulphonic acid --> (acid) H acid \sM (alkaline) aniline or b -naphthylamine; (7) H acid \sM (alkaline) benzidine-2 : 2<1>-disulphonic acid --> p-xylidine --> (alkaline) H acid. Samples have been furnished under Sect. 2 (5) of the following dyestuffs: (1) and (2) acetyl H acid \sM benzidine-2 : 2<1>-disulphonic acid --> resorcin or b -naphthol; (3) benzidine-2 : 2<1>-disulphonic acid \sQ H acid \sQ a -naphthylamine; (4) benzidine-2 : 2<1>-disulphonic acid \sQ J acid \sQ H acid. The Provisional Specification refers to the use of aminonaphthol sulphonic acids and amino, phenolic and aminophenolic components in general.