Patent GB-775385-A (GB)
Title: Improvements relating to chromium-containing azo dyestuffs and their use
Filed: 1954-11-24
Abstract: The invention comprises complex chromium compounds of formula:-(F1 - M1 - F2)M2 wherein M1 is a chromium atom bound in complex linkage, M2 is a monovalent cation, F1 is a metallizable monoazo dyestuff and F2 is a metallizable azo-methine dyestuff, which dyestuffs apart from any carboxyl groups taking part in the complex formation contain no further acid water-solubilizing groups.  The above compounds are prepared by reacting simultaneously or in any order desired, a chroming agent, a metallizable monoazo dyestuff and a metallizable azomethine dyestuff, or the appropriate amino and aldehyde compounds which form the azomethine dyestuff, the dyestuffs containing no acid water solubilizing groups except complexforming carboxyl groups, under conditions such that a compound of the above formula is obtained.  The monoazo and azomethine dyestuffs used in the process contain in the neighbouring positions to the azo or azomethine bridge a metallizable substituent or a group convertible thereto (e.g. on one side a hydroxyl or enolizable carbonyl group and on the other a hydroxyl or carboxy or alkoxy group).  The monoazo dyestuffs are obtained from diazotized o - hydroxy - or - alkoxy - or -carboxy - amino aromatic compounds by coupling with azo components which couple ortho to a hydroxy or enolizable carbonyl group.  The metallizable azomethine dyestuffs are obtained by reacting an aromatic o - hydroxy - or - carboxy - amino compound with an aromatic o - hydroxyaldehyde. The dyestuff components may contain further substituents such as halogen atoms and alkyl, alkoxy, nitro, acylamino, alkyl and aryl sulphonyl, sulphonic acid dialkylamide groups or sulphonic acid phenyl alkylamide groups.  The preferred substituents for use in the dyestuffs used for textile dyeing are non-acid water solubilizing substituents such as sulphonamide, N-monosubstituted sulphonamide, sulphonic acid N - alkyl - N - alkanolamide, alkyl and alkenyl sulphonyl and acetylamino groups.  The specified chroming agents are normal and complex salts of chromium including salts of chromosalicyclic acid.  The metallization may be carried out in the warm in organic or inorganic diluents in a neutral to alkaline medium and using at least one atom of chromium to two dyestuff molecules.  A preferred procedure is to convert one dyestuff component, preferably the monoazo component, into a chromium complex containing a chromium atom to one dyestuff molecule, in known manner, and then to react with the other dyestuff in aqueous or organic solution at a pH of 3-9.  The 1 : 1 chromium : dyestuff complex used in above process may be an addition compound thereof with metallizable organic compounds which are not dyestuffs such as salicylic acid or sulphosalicyclic acid.  The dyestuffs dye wool and synthetic polypeptides in orange, yellow, brown, green and blue shades.  In examples: (1) 2 - hydroxybenzaldehyde or 3 : 5 - dichloro - 2 - hydroxybenzaldehyde is reacted with 2 - aminophenol or 4 - chloro - or - nitro - or - methylsulphonyl - 2 - aminophenol and the reaction mixture reacted further with the 1 : 1 chromium complex of 4 - methylsulphonyl - 2 - aminophenol --> 1 - (31 - chlorophenyl) - 3 - methyl - 5-pyrazolone; (2) the chromium complex consisting of one molecule of 4 - nitro - 2 - aminophenol --> 1 - phenyl - 3 -methyl-5 - pyrazolone, one chromium atom and one molecule of sulphosalicylic acid is reacted with a mixture of 2 - hydroxybenzaldehyde and 4 - methylsulphonyl - 2 - aminophenol; (3) 4-methylsulphonyl - 2 - aminophenol --> 2-naphthol, 2 - aminophenol and 2 - hydroxybenzaldehyde are reacted together with ammonium chromosalicylate.  In a Table the following additional reaction components are specified (a) 1 : 1 complexes of the monoazo dyes: - 2 - aminobenzoic acid or 4 - chloro - 2 - aminobenzoic acid --> 1 - phenyl - 3 -methyl - 5 - pyrazolone, 5 - nitro - 2 - aminophenol --> 1 - phenyl-3 - methyl - 5 - pyrazolone, 4 - nitro - 2 - aminophenol --> p - cresol or 3 : 4 dimethylphenol, 2 - aminophenol - 4 - sulphonamide --> 1 - 31 - sulphonamido - phenyl) - 3 - methyl - 5 - pyrazolone, 4 - methoxy - 2 - aminophenol --> 1 - hydroxynaphthalene - 3 - sulphodimethylamide and 1 - amino - 2 - naphthol --> 2 - naphthol or 2 - hydroxynaphthalene - 6 - sulphomethyl - ethanolamide; (b) azomethine dyestuff components:- 2 - hydroxy - 1 - naphthaldehyde; 1 - amino - 2 - naphthol, 2 - aminobenzoic acid, 4 - chloro - 2 - amino - benzoic acid and 2 - aminophenol-4 - sulphonamide.