Patent GB-479708-A (GB)
Title: Sulphonic acids, insoluble azo-dyestuffs derived from these acids and processes for their preparation
Filed: 1937-01-06
Abstract: Insoluble azo dyes are made on the fibre by impregnating or printing the fibre with a 2-alkyl- or substituted alkyl aminonaphthalene-1-sulphonate and developing with a diazo compound of an amine which is free from water-solubilizing groups.  The azo group displaces the sulpho group in 1-position.  Coupling may occur in mineral acid solution and the dyeings can be produced on wool or silk.  The coupling components may be made up into preparations with the diazo compound in a form capable of being caused to couple by treatment in an acid medium, such as a diazoamino compound or a nitrosamine, or with the diazotizable base with or without sodium nitrite.  In examples: (3) cotton is impregnated in a bath containing sodium 2-methylaminonaphthalene - 1 - sulphonate, urea and glycerine, dried and developed in an acid or neutral solution with diazotized o-chloraniline, 2 : 5-dichloraniline, 1-amino - 2 - nitro - 4 - chloro-3 : 6-dimethylbenzene or o-chloro or o-bromo-p-nitroaniline; the 2-aminoethyl-, or acetyl-, benzoyl- and sulphonyl-aminoethylaminonaphthalene - 1 - sulphonates and 2 : 4-dinitroaniline are also specified as components; (4) a fabric of vegetable or animal fibres is printed with a paste containing 2-bromo-4-nitroaniline, sodium sulphoricinate, glycerine, sodium 2-benzoylaminoethylaminonaphthalene-1 -sulphonate, sodium nitrite and starch tragacanth thickening, dried, developed in an acid bath and soaped (blue).  The above-mentioned compositions may also be used for printing, the shades being developed by acid treatment.  The 2 - alkylaminonaphthalene - 1 - sulphonic acids are made by reacting primary aliphatic amines and their derivatives with 2-naphthol-1-sulphonic acids in presence of sulphurous acid or its salts.  In examples: (1) 2-methylaminonaphthalene-1-sulphonic acid is made from sodium 2 - naphthol - 1 - sulphonate, sulphur dioxide and methylamine; (2) 2-aminoethylaminonaphthalene-1-sulphonic acid is similarly made using ethylenediamine; the acetyl, benzoyl and sulphonyl derivatives are made by acidylation.  Samples have been furnished under Sect. 2 (5) of (1) the product of example (1), (2) sodium 2-n-butylaminonaphthalene-1-sulphonate; (3) 2-n-amylamino-naphthalene-1-sulphonic acid.  Specifications 15120/90, [Class 2], 7339/92, [Class 15], 18726/00, 26023/08, [both in Class 2]; 21199/10, 230,457, and 249,717, [all in Class 2 (iii)], are referred to.  The Specification as open to inspection under Sect. 91 comprises the use of butylamine, amylamine and cyclohexylamine as in (1) above and states that the 2-amino group may be substituted by a saturated hydrocarbon radical.  The following combinations are also tabulated: 1 - amino - 2 - nitro - 4 - chloro-3:6-dimethylbenzene--> benzoylaminoethylaminonaphthalene sulphonate, o-chloraniline, 2 : 5-dichloraniline, 1-amino-2-nitro-4-chloro-3 : 6-dimethylbenzene, o - chlor - p - nitroaniline or nitrocresidine --> sodium 2-amyl- or 2-cyclohexylaminonaphthalene - 1 - sulphonate.  This subject-matter does not appear in the Specification as accepted.