Patent GB-838337-A (GB)
Title: Stabilisation ofú¾-triazinylamino compounds using a phosphate buffer
Inventor: HESLOP ROBERT NORMAN
IPC: D06P1/382
Filed: 1956-04-20
Abstract: The invention comprises a composition containing one or more compounds selected from amino-s-triazines and compounds containing at least one s-triazin-2-ylamino group substituted in the triazine nucleus by at least one halogen atom, and a phosphate buffer which in aqueous solution maintains a pH of not less than 6 and not more than 8.  The preferred compositions are those where the compound is a 4,6-dichloro-s-triazin-2-ylamino compound and where there is at least 10% (by weight of the triazine compound) of a phosphate buffer which in aqueous solution has a pH of not less than 6 and not more than 7. The invention includes a process for improving the stability of compounds of the type defined by adding to the compound a phosphate buffer of the type defined and a process for manufacturing the compositions defined above by reacting a cyanuric halide or a 2,4-dihalogeno-s-triazine with ammonia or a primary or secondary amine or polyamine so that at least one halogen atom remains attached to a carbon atom of the triazine nucleus and adding to the product, before, during or after its isolation, a phosphate buffer of the type defined.  The buffer e.g. a mixture of Na2HPO4 and KH2PO4, may also be added before or during the reaction period in the solid state or in aqueous solution if the reaction medium is aqueous and may also be mixed with the dried product or a filtered-off residue of the product may be washed with a solution of the buffer.  The compounds stabilized may be of the type obtained by reacting cyanuric chloride or bromide or a 2,4-dihalo-s-triazine bearing an alkyl, aryl, alkoxy, aryloxy, alkylmercapto, arylmercapto or hydroxy group in position 6 with a colourless alkyl or aryl amine which may contain water-solubilizing groups such as methylamine, butylamine, diethylamine, ethanolamine, cyclohexylamine, aniline, b -naphthylamine, metanilic acid, 2 - naphthylamine - 6-sulphonic acid, 2 - naphthylamine - 4,8 - disulphonic acid, 1 - amino - 8 - naphthol - 3,6-disulphonic acid, 2 - amino - 5 - naphthol - 7-sulphonic acid, 2 - amino - 8 - naphthol - 6 - sulphonic acid, p - toluidine, m - anisidine, 2,4-dichloroaniline, ethylene diamine, p - phenylene diamine, 4,41 - diamino - stilbene - 2,21 - disulphonic acid and 2,4- and 2,5-diaminobenzene sulphonic acid.  The amine used may also contain a chromophore which gives a dyestuff product (see Group IV (c)).  In examples the sodium salts of (1) m - (41,61 - dichloro - s - triazin - 2-yl)-aminobenzene sulphonic acid, and (6) 2-(41,61-dichloro - s - triazin - 2 - yl) amino - 8 - naphthol-6-sulphonic acid are treated with Na2HPO4 and KH2PO4. Specifications 772,030, 774,925, 781,930, 785,120, 785,222, 826,405 and 838,335 are referred to.ALSO:The invention comprises a composition containing one or more compounds selected from amino-s-triazines and compounds containing at least one s-triazin-2-ylamino group substituted in the triazine nucleus by at least one halogen atom, and a phosphate buffer which in aqueous solution maintains a pH of not less than 6 and not more than 8.  The preferred compositions are those where the compound is a 4,6-dichloro-s-triazin-2-ylamino compound and where there is at least 10% (by weight of the triazine compound) of a phosphate buffer which in aqueous solution has a pH not less than 6 and not more than 8. The invention includes a process for improving the stability of compounds of the type defined by adding to the compound a phosphate buffer of the type defined and a process for manufacturing the compositions defined above by reacting a cyanuric halide or a 2,4-dihalogeno-d-triazine with ammonia or a primary or secondary amine or polyamine so that at least one halogen atom remains attached to a carbon atom of the triazine ring and adding to the product, before during or after its isolation, a phosphate buffer of the type defined.  The buffer, e.g. a mixture of Na2HPO4 and KH2PO4, may also be added before or during the reaction period in the solid state or in aqueous solution if the reaction medium is aqueous and may also be mixed with the dried product or a filtered-off residue of the product may be washed with a solution of the buffer.  The compounds stabilized may be of the type obtained by reacting cyanuric chloride or bromide or a 2,4-dihalo-s-triazine bearing an alkyl, aryl, alkoxy, aryloxy, alkylmercapto, arylmercapto or hydroxy group in position 6 with a colourless alkyl or aryl amine or with a chromophore-containing amine such as an amino azobenzene or an amino-anthraquinone.  In the examples, using a mixture of Na2HPO4 and KH2PO4 the dyestuffs, derived from the following diazo components and coupling components, are stabilized: (2) aniline and 1-(41,61-dichloro - s - triazin - 2 - yl) - amino - 8 - naphthol-3,6-disulphonic acid by adding buffer solution and mixing buffer with the moist filter cake; (3) metanilic acid and 1-acetylamino-8-naphthol-3,6-disulphonic acid and then condensing the 1-amino group with cyanuric chloride by mixing buffer with the dry filter cake; (4) p-amino-acetanilide and 1-(41,61-dichloro - s - triazin - 2 - yl) - amino - 8 - naphthol - 3,6-disulphonic acid by mixing buffer with the dry filter cake; (5) 2-amino-4-sulphodiphenyl ether and 1-(41,61-dichloro-s-triazin-2-yl)-amino - 8 - naphthol - 3,6 - disulphonic acid by adding buffer solution and mixing buffer with the moist filter cake; (7) 2-chloro-4-anilino-6-(31-amino-41-sulphoanilino) -s-triazine and 1-(21-chlorophenyl) - 3 - methyl - 5 - pyrazolone by mixing with the moist filter cake.  The anthraquinone dyes, derived from the following components, are stabilized: (8) cyanuric chloride and 1 - b - sulphato - isopropylamino - 4 - (41 - aminoanilino) - anthraquinone - 31 - sulphonic acid by adding buffer solution, washing the filter cake with buffer solution and mixing buffer with the moist filter cake; (9) cyanuric bromide and 1 - amino - 2,31,51 - trisulpho - 4 - (41 - aminoanilino)-anthraquinone by adding buffer solution and mixing buffer with the moist filter cake the stabilization of the product of cyanuric chloride and 1-(41-amino-anilino)-anthraquinone - 2,31 - disulphonic acid by adding buffer solution, washing the filter cake with buffer solution and mixing buffer with the dried dyestuff is described in the Provisional Specification. Specifications 772,030, 774,925, 781,930, 785,120, 785,222, 826,405 and 838,335 are referred to.