Patent GB-741602-A (GB)
Title: Manufacture of metalliferous azo-dyestuffs
IPC: C09B45/16
Filed: 1952-07-18
Abstract: A solution of sodium-potassium chromosalicylate is made by boiling an aqueous solution of chromic sulphate with salicylic acid to yield chromosalicylic acid which is dissolved by the addition of sodium hydroxide and potassium hydroxide added until the solution is alkaline to phenolphthalein.ALSO:The invention comprises cobalt or chromium compounds which contain one or two monazo-dyestuffs which are free of sulphuric and carboxylic acid groups and are of formula <FORM:0741602/IV(c)/1> where R1 is a benzene residue bound to the azo linkage in ortho position relatively to the hydroxyl group, and R2 is a benzene residue, and in which at least one of R1 and R2 contains an aliphatic group or a halogen atom, or two monoazo dyes of which one corresponds to the above formula and the other is an 5, 51-dioxymonoazo dyestuff of the benzene-azonaphthalene series free of sulphonic and carboxylic acid groups, and in which the ratio of the number of cobalt or chromium atoms to monoazo dyestuff molecules is less than 1 : 1 and is advantageously about 1 : 2.  They may be made by treating the appropriate dyestuff or mixture of dyestuffs with an agent yielding cobalt or chromium so that the resulting metalliferous dyestuff contains less than one atom of metal per mol. of dyestuff. The metallization may be effected by using the appropriate quantities of reagents and/or by using a weakly acid to alkaline medium. Complex cobalt or chromium compounds of aliphatic oxy- or di-carboxylic acids are especially suitable metal-yielding agents and particularly complex chromium compounds of aromatic-ortho-oxy-carboxylic acids. Divalent cobalt compounds e.g. the sulphate, acetate and hydroxide may also be used. Metallization is preferably effected at raised temperature and salts of organic acids, bases and solvents may be present if desired.  The chromium-containing dyestuff may also be made by treating, preferably in a neutral to alkaline medium, a chromium compound of one of the dyestuffs containing one atomic proportion of metal per molecular proportion of dyestuff with advantageously an equimolecular quantity of a metal-free dyestuff which is the same as that of the chromium compound or is the other of the two dyestuffs to be present in the product.  The 1 : 1 complexes may be made by treating the free monoazo dyestuff in an acid medium with an excess of a salt of trivalent chromium at raised temperature in the presence of a solvent such as alcohol if necessary under dealkylating conditions.  Dyestuffs of the above formula are made by coupling an ortho-oxydiazocompound of the benzene series free of sulphonic and carboxylic acid groups and containing an unsubstituted sulphonamide group, with a 1-phenyl-3-methyl-5-pyrazolone which if necessary contains an aliphatic group or halogen atom in the phenyl group.  Preferably R2 contains the aliphatic group or halogen atoms. Specified amines where diazo-compounds may be used are: 6-chloro-2-amino-1-oxy-benzene-4-sulphonamide, 4-methyl-2-amino-1-oxy-benzene -5- or -6- sulphonamide and particularly 2-amino-1-oxybenzene -4- or -5-sulphonamide, the last two components being coupled exclusively with 1-phenyl-3-methyl-5-pyrazolones containing the necessary substituent: Specified coupling components are: 1-(31 and 41-methyl-, 41-tertiary-amyl-, 31-trifluoromethyl-, 21, 51- dichloro- and -dibromo- 21-chloro, 21- and 41-fluoro- and particularly 31- and 41 chlorophenyl)-3-methyl-5-pyrazolone; 1-phenyl-3-methyl-5-pyrazolone is specified for coupling with the appropriately substituted sulphonamides listed above.  The dyestuffs may be isolated before metallization or metallized in the form of filter-cakes or in the coupling mixture without prior separation.  The ortho, ortho1-dioxy-monoazo-dyestuffs of the benzene-azo-naphthalene series used in the preparation of mixed dyes may be made by coupling the appropriate diazo-benzene compound with the required naphthol. Specified amines whose diazo-compounds may be used are 4- and 5-nitro- and -chloro-2-amino-1-oxybenzene, 6-acetylamino-4-nitro-and 4-acetylamino-6-nitro-2-amino-1-oxybenzene, 2-amino-1-oxybenzene-4-methyl sulphone and -4- and -5-sulphonic acid-N-methyl-, -ethyl-,-B-oxyethyl- and -phenyl-amide and the above mentioned ortho-oxy-amines.  Specified naphthols: 5-chloro- and 5, 8-dichloro-1-oxy-naphthalene, b -naphthol, 6-bromo- and -methoxy- and -7- methoxy-2-oxynaphtha lene and 1-acetyl-, -butyryl- and -benzoylamino -7-oxynaphthalene. Preferred are metal compounds of dyestuffs of formula:- <FORM:0741602/IV(c)/2> where R1 is a benzene residue bound to the azo linkage in ortho-position relative to the hydroxyl group, and m is 1, 2 or 3. The dyestuffs dye silk, leather and especially wool and super polyamids and neger superpolymethanes from weakly alkaline to weakly acid baths in yellow, brown and red shades.  Examples are provided of the use of certain of the above specified reagents in the preparation of dyestuffs, an additional pyrazolone used being 41(bromo-phenyl)-3-methyl-5-pyrazolone, and the use of dyestuffs in dyeing wool and nylon fibres.  Specifications 637,404, 693,245 and 706,370 are referred to.