Patent GB-347097-A (GB)
Title: Manufacture of dyestuffs
Filed: 1929-12-11
Abstract: Azo dyes and soluble metal compounds thereof; substantive and mordant dyes, dyeing with; regenerated celluloses, dyeing.-Azo dyes containing copper which are capable of dyeing "stripey" viscose in level blue shades fast to light are obtained by treating with agents yielding copper disazo dyes of the type R1-N=N-R2-N=N-R3, in which R1 is the residue of a diazotizable aromatic amine, R2 is the residue of an aromatic middle component carrying an OH group in o-position to the second azo group, and R3 is the residue of 2 : 5 : 7-aminonaphtholsulphonic acid or an N-substituted derivative thereof, coupled alkaline.  Such coppering treatment may be applied to the dyestuffs in substance, in the dyebath, or on the fibre, or the coupling with the 2 : 5 : 7-acid or N-derivative thereof to form the parent dyestuffs may be effected in presence of agents yielding copper.  The products are applicable also for dyeing vegetable fibres, animal fibres such as natural or loaded silk, and regenerated cellulose fibres in general.  The following example is specified. The dyestuff 2-aminonaphthalene-4 : 8-disulphonic acid --> m-amino-p-cresol --> (alkaline) phenyl-2 : 5 : 7-acid is heated for 1 hr. at 50 DEG  C. with an ammoniacal solution of copper sulphate; the product dyes cotton blue and gives level shades fast to light on viscose; similar products dyeing blue to green-blue are obtainable by replacing the initial diazo component by sulphanilic or metanilic acid or replacing the end component by 2 : 5 : 7-acid; a product dyeing red-blue is obtainable from the dyestuff sulphanilic acid --> acetyl-o-aminophenol (acetyl group eliminated by hydrolysis after coupling) --> (alkaline) phenyl - 2 : 5 : 7 - acid. Specifications 1611/15, 12932/15, 15127/15, 209,723, 297,003, 297,687, 306,859, and 306,908, [all in Class 2 (iii), Dyes &c.], are referred to.  The Specification as open to inspection under Sect. 91 (3) (a) comprises also the similar treatment with agents yielding metals such as copper, chromium, nickel, iron, cobalt, titanium, or aluminium, of any azo dyestuffs of the general formula (R1-N=N-R2-N=N-)x R3, in which R1 is any aromatic residue, R2 is an aromatic residue carrying in o-position to the second azo group an OR group, R being H or a salt-forming group such as CH2-COOH, R3 is the residue of a component capable of coupling once or several times, and x is a whole number. As end components are specified 2 : 5 : 7- and 2 : 8 : 6-aminonaphthol-sulphonic acids and N-acidyl, N-alkyl, N-aryl, triazine, quinazoline, pyridazine, and pyrimidine derivatives of these and of other aminonaphthols including 1 : 8-aminonaphthols.  A further example is given in which a tetrakisazo dyestuff, obtainable by diazotizing 2 mols. of the monoazo product sulphanilic acid --> acetyl-o-aminophenol (acetyl group eliminated by hydrolysis after coupling) and coupling with 1 mol. of 5 : 51-dioxy-2 : 21-dinaphthylamine-7 : 71-disulphonic acid, is heated for 2 hrs. at 75-95 DEG  C. with a solution of copper sulphate; the product dyes cotton brownish red-violet shades fast to light.  A table is also given showing the shades obtainable with the following additional metal compounds, viz. the copper compounds from metanilic acid --> m-amino-p-cresol --> phenyl-2 : 8 : 6-acid or H-acid, 2-naphthylamine-4 : 8-disulphonic acid --> m-amino-p-cresol --> 1 : 8 : 4 acid or H-acid, H-acid --> m-amino-p-cresol glycollic acid ether --> benzoyl-2 : 5 : 7-acid, 2-naphthylamine-4 : 8-disulphonic acid --> m-amino-p-cresol glycollic acid ether --> phenyl-2 : 5 : 7-acid, and (sulphanilic acid --> o-aminophenol)2 \sQ the urea of 2 : 5 : 7-acid or 5 : 51-dioxy-2 : 21-dinaphthylamine-7 : 71-disul phonic acid, and the chromium compounds from 2-naphthylamine-4 : 8-disulphonic acid --> m-amino p-cresol --> phenyl-2 : 5 : 7-acid, sulphanilic acid --> m-amino-p-cresol --> 3-methyl-5-pyrazolone, p-toluidine-5-sulphonic acid --> m-amino-p-cresol --> 3-methyl-5-pyrazolone, sulphanilic acid --> m-amino-p-cresol --> acetoacetanilide or barbituric acid, and sulphanilic acid --> o-aminophenol --> 3-methyl-5-pyrazolone.  This subject-matter does not appear in the Specification as accepted.