Patent GB-369991-A (GB)
Title: Manufacture of azo-dyestuffs containing chromium
IPC: C09B45/01
Filed: 1930-12-18
Abstract: Azo dyes, complex chromium compounds of; regenerated celluloses, dyeing.--Azo dyestuffs containing at least one atom of chromium for each chromable group present in the molecule are obtained by the use as chroming agent of a basic chromium sulphate.  The products are applicable for dyeing animal fibres such as wool, natural or loaded silk, and leather, cotton and other vegetable fibres, and regenerated cellulose fibres; they are also suitable for incorporation in varnishes having a basis of natural or artificial resins, such as phenolformaldehyde or urea-formaldehyde condensation products, or having a basis of cellulose derivatives.  The following examples are specified: (1) An aqueous solution of the dyestuff, 4 - nitro - 2 - aminophenol - 6 - sulphonic acid --> acetoacetanilide, is boiled for fifteen hours under reflux with addition of a basic chromium sulphate containing 8,4 parts Cr2O3 to 12,6 parts H2SO4; the product dyes wool from a sulphuric acid bath fast yellow; when the coupling component is replaced by 1-phenyl-3-methyl-5-pyrazolone the dyeings are yellowish-orange. (2) An aqueous solution of the dyestuff, 1 : 2-aminonaphthol-4-sulphonic acid --> 1-(3<1>-sulphamido) phenyl-3-methyl-5-pyrazolone, is boiled for 20 hours under reflux with addition of the basic chromium sulphate of (1); the product dyes wool fast rose; when the diazo component is the nitrated diazo compound the dyeings are yellowish red; when the parent dyestuff is 1 : 2-aminonaphthol-4-sulphonic acid --> 1-naphthol-8-sulphamide the dyeings are greenish-blue.  (3) An aqueous solution of the dyestuff, 2-aminophenol-4 : 6-disulphonic acid --> 1-phenyl-3-methyl-5-pyrazolone, is boiled for 15 hours with additional of a basic chromium sulphate containing 11,7 parts Cr2O3 to 14,7 parts H2SO4; the product dyes wool level orange; when the parent dyestuff is 1 : 2-aminonaphthol-4-sulphonic acid --> 1-(3<1>-sulpho) phenyl-3-methyl-5-pyrazolone the dyeings are rose. (4) An aqueous solution of the dyestuff, 2 : 1-aminonaphthol-4 : 8-disulphonic acid --> b -naphthol, is boiled for 20 hours under reflux with addition of a basic chromium sulphate containing 8,4 parts Cr2O3 to 5,4 parts H2SO4; the product dyes wool reddish-blue; the basicity of the chromium sulphate used may be widely varied.  (5) An aqueous solution of the dyestuff, 1 : 2-aminonaphthol-4-sulphonic acid --> a -naphthol, is boiled for 24 hours with addition of a basic chromium sulphate containing 15,2 parts Cr2O3 to 24,6 parts H2SO4; the product dyes wool fast greenish blue; when the coupling component is replaced by b  - naphthol and a more basic sulphate (e.g. that from 1 mol. Cr2O4 and 2 mols. H2SO4) is used, the dyeings are reddish blue.  (6) A mixture of the dyestuff, 2-aminophenol-4-sulphamide --> 1-(3<1>-sulphamido) phenyl-3-methyl-5-pyrazolone, with water is heated for 12 hours under pressure at 115-120 DEG  C. with addition of a basic chromium sulphate containing 9 parts Cr2O3 to 13,6 parts H2SO4; the product dyes wool fast reddish orange.  (7) An aqueous solution of the dyestuff, 5-nitro - 2 - aminophenol --> 2 : 6 - naphthylamine-sulphonic acid, is heated for 10 hours under pressure at 115-120 DEG  C. with addition of a basic chromium sulphate containing 9 parts Cr2O3 to 8,7 parts H2SO4; the product, after being rendered more freely soluble in water by solution in caustic soda lye, neutralizing with acetic acid and salting out, dyes wool fast blueish green.  (8) An aqueous solution of the dyestuff, 5-nitro-2-aminophenol --> phenyl-2 : 5 : 7 - acid, is heated for 15 hours under pressure at 125-130 DEG  C. with addition of a basic chromium sulphate of which 9 parts contain 3,8 parts Cr2O3; the product, after being solubilized as in (7) dyes wool from an acid bath, and cotton or regenerated cellulose, e.g. viscose, silk from a neutral or feebly alkaline bath, greenish blue.  (9) Wool is dyed by treatment for 30 minutes at 60 DEG  C. in a dyebath containing the dyestuff and sulphuric acid, further treatment with addition of more sulphuric acid while gradually heating to boiling, and finally boiling for 30-45 minutes.  (10) Cotton is dyed by treatment in a dyebath containing the dyestuff, Glauber's salt and common salt while heating for 15 minutes from 60 or 70 DEG  C. to boiling and finally boiling for 30-45 minutes.  (11) 4-5 parts of the dyestuff are dissolved in 1000 parts of a nitrocellulose varnish; suitable additions may be incorporated to produce a matt or a covering varnish. Specification 26460/12 is referred to.  The Specification as open to inspection under Sect. 91 (3) (a) comprises also the use of nonbasic chromium sulphates as chroming agents.  This subject-matter does not appear in the Specification as accepted.  Reference has been directed by the Comptroller to Specification 26460/12, [Class 2 (iii), Dyes &c.].