The invention relates to defined tetrakisazo dyes and mixtures thereof with defined trisazo dyes, their production and their use, especially for the dyeing of leather.
In U.S. Pat. No. 4,479,906 there are described trisazo dyes of the formula 
in which
AO is the radical of an aromatic-carbocyclic diazo component,
BO is the radical of a coupling component which contains hydroxyl and/or amino groups,
n is the integer 1 or 2,
one XO is hydroxyl and the other XO is amino,
ZO is 
TO is hydrogen, methyl, ethyl, benzyl, xcex2-hydroxyethyl, xcex2-hydroxypropyl, xcex2-cyanoethyl, xcex2-carboxyethyl or xcex2-carbalkoxyethyl of a total of two to five carbon atoms,
RO is hydrogen, hydroxyl, chloro, bromo, nitro, methyl, ethyl or carboxyl and
R1O is hydrogen, methyl, ethyl, chloro, bromo, cyano, nitro, hydroxysulphonyl, carboxyl or alkoxycarbonyl,
there being described in particular also some tetrakisazo dyes in which in the above formula n is 2, the two sulpho groups are in the positions meta to each XO (as corresponds to H-acid), ZO is a radical of formula (2). AO is the radical of an aminoazobenzene diazocomponent and BO is the radical of certain aminobenzene coupling components. These dyes are described also for the dyeing of leather in green to black shades.
It has now been found that tetrakisazo dyes of the below indicated structure of formula (I) are particularly valuable anionic dyes for obtaining dyeings of intensive dark shades, in particular for the penetration dyeing of leather in dark shades of high fastnesses, especially when combined with the below defined trisazo dyes of formula (X).
The invention relates to the defined dyes and dye mixtures, their production and their use.
The invention, thus, provides a tetrakisazo dye of formula 
wherein
one of the two symbols X and Y signifies xe2x80x94OH and the other signifies xe2x80x94NH2,
Z signifies a radical of formula
xe2x80x94W1xe2x80x94Nxe2x95x90Nxe2x80x94B2 xe2x80x83xe2x80x83(xcex1) 
or, if Y signifies xe2x80x94OH, also a radical of formula
xe2x80x94W2xe2x80x94Nxe2x95x90Nxe2x80x94D xe2x80x83xe2x80x83(xcex2),
Q1 signifies xe2x80x94SO2xe2x80x94 or xe2x80x94COxe2x80x94,
Q2 signifies the direct bond or, if Q1 is xe2x80x94SO2xe2x80x94, also a group xe2x80x94SO2xe2x80x94,
B1 signifies the radical of a coupling component Hxe2x80x94B1,
B2 signifies the radical of a coupling component Hxe2x80x94B2,
D signifies the radical of a diazo component Dxe2x80x94NH2,
W1 signifies the radical of a bicyclic bisdiazo component,
W2 signifies the radical of a bicyclic middle component and
M signifies hydrogen or a cation,
or a mixture of two or more tetrakisazo dyes of formula (I).
Formula (I) comprises in particular the following formulae 
Thus, the invention provides in particular a dye of formula (Ia), (Ib) or (Ic) or a mixture of two or more thereof.
A particular further feature of the invention is represented by a mixture of at least one dye of the above formula (I) and at least one trisazo dye of formula 
in which B1, D, Q1, Q2 and M have the significances indicated above for formula (I).
The dyes of the invention may be produced by means of diazotization and coupling reactions, in order to form the azo groups, in a manner conventional per se. In particular, a process for the production of the tetrakisazo dyes of the invention is characterized in that for the production of a dye of formula (Ia) the bisdiazocompound of a diamine of formula 
is coupled at one side to the 3-position of a bis-coupling component of formula 
the obtained azodiazocompound is either first coupled to a coupling component Hxe2x80x94B1, to give an intermediate of formula 
and the diazocompound of an amine of formula
Dxe2x80x94Nxe2x95x90Nxe2x80x94W2xe2x80x94NH2 xe2x80x83xe2x80x83(V) 
is coupled to the 6-position of the intermediate of formula (IV), or the azodiazocompound is first coupled in the 6-position with the diazocompound of an amine of formula (V) and then coupled to a coupling component Hxe2x80x94B1, for the production of a dye of formula (Ib) the bisdiazocompound of a diamine of formula (II) is coupled at one side to the 3-position of a bis-coupling component of formula (III) and the obtained azodiazocompound is either first coupled to a coupling component Hxe2x80x94B1, to give an intermediate of formula (IV), and then the bisdiazocompound of a diamine of formula
H2Nxe2x80x94W1xe2x80x94NH2 xe2x80x83xe2x80x83(VI) 
is coupled at one side to the 6-position of the intermediate of formula (IV) and the obtained trisazodiazocompound is coupled to a coupling component Hxe2x80x94B2, or the azodiazocompound is first coupled in the 6-position with the bisdiazocompound of a diamine of formula (VI) and then the obtained disazobisdiazocompound is coupled to coupling components Hxe2x80x94B1, and Hxe2x80x94B2 or for the production of a dye of formula (Ic) the bisdiazocompound of a diamine of formula (VI) is coupled at one side to the 3-position of a bis-coupling component of formula (III) and the obtained azodiazocompound is either first coupled to a coupling component Hxe2x80x94B2 to give an intermediate of formula 
and then the bisdiazocompound of a diamine of formula (II) is coupled at one side to the 6-position of the intermediate of formula (VII) and the obtained trisazodiazocompound is coupled to a coupling component Hxe2x80x94B1, or it is first coupled in the 6-position with the bisdiazocompound of a diamine of formula (II) and then the obtained disazobisdiazocompound is coupled to Hxe2x80x94B1, and Hxe2x80x94B2.
The compounds of formula (V) may be produced by coupling the diazocompound of a diazocomponent of formula
Dxe2x80x94NH2 xe2x80x83xe2x80x83(VIII) 
to a middle component of formula (IX)
Hxe2x80x94W2xe2x80x94NH2 xe2x80x83xe2x80x83(IX). 
The trisazo dyes of formula (X) may be synthetized by coupling the diazocompound of a diazocomponent of formula (VIII) to a compound of formula (IV) or to its precursor azodiazocompound, before coupling of the diazoazocompound to Hxe2x80x94B1. If the starting compounds are the same as the corresponding ones employed for the production of the dyes of formula (I), this reaction sequence may be carried out together with the production of the tetrakisazo dye or dye mixture, choosing the molar ratios in a suitable way.
In the mixtures of tetrakisazo dyes of formula (I) and trisazodyes of formula (X) the molar ratio of tetrakisazo dye or tetrakisazo dye mixture to trisazo dye or trisazo dye mixture is e.g. in the range of 95/5 to 20/80, prferably 80/20 to 30/70, more preferably 75/25 to 40/60.
As diazocomponents of formula (VIII) there may be employed any known diazotizable amines, in particular of the benzene of naphthalene series, preferably containing at least one solubilizing substituent, which preferably is a sulpho group, a carboxy group, a carbamoyl group and/or a sulphamoyl group.
As diazo components of formula (VIII) come, in particular, into consideration those of the following formulae 
wherein
R1 signifies hydrogen, nitril, trifluoromethyl, nitro, xe2x80x94SO3M, xe2x80x94SO2NR4R5, xe2x80x94COOM or xe2x80x94CONR4R5,
R2 signifies hydrogen, nitro, xe2x80x94SO3M, xe2x80x94SO2NR4R5, trifluoromethyl, nitril, xe2x80x94COOM, xe2x80x94CONR4R5, C1-4-alkyl, C1-4-alkoxy, halogen or C1-2-mercaptoalkyl,
R3 signifies hydrogen, C1-4-alkyl, C1-4-alkoxy, halogen, C1-2-mercaptoalkyl, xe2x80x94NHxe2x80x94Ac, xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94CH3 or a radical of formula 
R4 signifies hydrogen, C1-4-alkyl, C1-3-alkylene-Rxe2x80x2 or C2-3-3-hydroxyalkyl,
R5 signifies hydrogen, C1-4-alkyl, C1-3-alkylene-Rxe2x80x2, C2-3-hydroxyalkyl, benzyl or a radical of formula 
Rxe2x80x2 signifies nitril, carbamoyl or xe2x80x94COOM,
R6 signifies hydrogen, nitro or xe2x80x94SO3M,
R7 signifies hydrogen, methyl, chlorine, nitro, xe2x80x94COOM or xe2x80x94SO3M,
R8 signifies hydrogen, halogen, nitro, xe2x80x94SO3M, xe2x80x94SO2NR4R5, methylsulphonyl, C1-4-alkyl or xe2x80x94NHxe2x80x94Ac,
R9 signifies hydrogen, halogen, nitro, xe2x80x94SO3M, xe2x80x94SO2NR4R5, methylsulphonyl, C1-4-alkyl or xe2x80x94NHxe2x80x94Ac,
R10 signifies nitro, xe2x80x94SO3M or xe2x80x94SO2NR4R5,
Ac signifies an aliphatic acyl group,
p signifies 0 or 1 and
r signifies 0 or 1,
R1 preferably signifies hydrogen or xe2x80x94COOM.
Of the alkyl and alkoxy groups with 1 to 4 carbon atoms, the lower molecular ones are preferred, in particular ethyl, methyl, ethoxy and methoxy. Halogen may in particular be fluorine, chlorine or bromine of which fluorine and, before all, chlorine are preferred.
Where in formula (a1) R3 signifies a radical of formula (axe2x80x2) this is preferably in para-position to the amino group, R1 preferably signifies hydrogen, R2 preferably signifies hydrogen or a sulpho group and, if R2 signifies a sulpho group, this is preferably in meta-position to the azo group and R6 and R7 preferably signify both hydrogen or, if R2 signifies hydrogen, R6 signifies preferably a nitro group and R7 signifies preferably a carboxy group or a sulpho group, the two substituents R6 and R7 being placed in the para-position to the imino group and in one of the two ortho-positions to the imino group.
Where the symbol R3 does not signify a radical (axe2x80x2), R3 preferably signifies hydrogen and R1 preferably signifies hydrogen or xe2x80x94COOM. According to a preferred feature, in this case in formula (a1) one or both of the positions ortho to the primary amino group and, more preferably, also one or both of the positions meta to the primary amino group are unsubstituted. According to a further preferred feature, if R1 signifies xe2x80x94COOM, this is in position ortho or para to the diazotizable primary amino group.
R4 preferably signifies hydrogen.
R5 advantageously signifies hydrogen, methyl, ethyl, hydroxyethyl or a radical of formula (axe2x80x3), in which R7 preferably signifies hydrogen or carboxy.
The aliphatic acyl group Ac advantageously signifies the radical of a low molecular aliphatic carboxylic acid, preferably of an alkanoic acid with 2 to 4 carbon atoms, more preferably acetyl or propionyl, of which acetyl is preferred.
Most preferably the diazo component of formula (a1) is an aminobenzoic acid, in particular anthranilic or p-aminobenzoic acid.
In formula (a2 ) preferably at least one of R8 and R9 has a significance other than hydrogen, more preferably R9 has a significance other than hydrogen and R8 signifies hydrogen, a nitro group or a sulpho group.
The primary amino group in formula (a4) may be in any of the positions xcex1 and xcex2 of the naphthalene ring and, if p signifies 1, the sulpho group may be in any of the other available positions, preferably so that at least one vicinal position to the amino group is unsubstituted; e.g. if the amino group is in position 1, the sulpho group is preferably in any of the positions 3 to 8, more preferably 4 to 8, and if the amino group is in the position 2, the sulpho group is e.g. in position 1 or in any of the positions 4 to 8, more preferably 5, 6 r 7. A preferred diazocomponent of formula (a4) is naphthionic acid.
The compounds (a5) are indicated in the free amino form, as diazo components they are however usually employed directly in the form of the respective commercially available diazonium compounds 1-diazonium-2-naphthol-4-sulphonic acid (in which r=0) and 1-diazonium-6-nitro-2-naphthol-4-sulphonic acid (in which r=1).
Among the above diazo components are preferred those, which do not contain a hydroxy group in ortho position to the diazotizable amino group, in particular the compounds of formula (a1) and (a4).
Preferably Dxe2x80x94NH2 contains at least one hydrophilic substituent, preferably a substituent selected from the group consisting of xe2x80x94SO3M, xe2x80x94SO2NR4R5, xe2x80x94COOM and xe2x80x94CONR4R5, more preferably not more than one hydrophilic substituent per homocyclic aromatic nucleus.
As a middle component there is understood a compound that acts as a coupling component and that contains a diazotizable primary amino group or a group convertible to a diazotizable primary amino group and which compound, upon having been coupled with a diazo compound, if required after having converted a substituent convertible to a primary amino group to this primary amino group, is diazotized and the obtained azodiazocompound is then coupled to a further coupling component. As middle components, from which W1 derives, come preferably into consideration middle components containing a primary amino group.
The radical W2 and respectively the middle component of formula (IX), from which the radical W2 derives, contains two rings of aromatic character, of which one is a benzene ring and the other may be an optionally condensed second benzene ring (to give a naphthalene radical) or a benzene ring linked over a bridging group or a heterocyclic ring linked to the benzene ring, optionally over a heteroatomic bridging group. The diazotizable primary amino group is suitably a substituent of a benzene ring and the coupling position is suitably activated by at least one electron donor substituent, in particular by an amino group or preferably a hydroxy group. The middle component of formula (IX) preferably is a compound of the aminonaphthalene series (more preferably of the aminonaphthole series), of the 1-(aminophenyl)-5-pyrazolone or -5-aminopyrazol series or of the sulphanilylamino-phenol or -pyrimidone series. Where the middle component is of the pyrazole series, it is preferably a pyrazolone in which the 3-position may be substituted with carboxy or C1-4-alkyl, preferably methyl, and where the primary amino group at the 1-positioned phenyl radical is in meta- or para-position to the pyrazole radical. Where the middle component is of the sulphanilylaminophenol series, the phenolic hydroxy group is preferably in meta-position and the two benzene rings preferably do not contain any further substituents. Where the middle component is of the sulphanilylaminopyrimidine series, this is e.g. a middle component as described in GB-A 2 276 174, among which 6-amino-2-sulphanilylamino-3-H-pyrimidin-4-one and 2-sulphanilylamino-3-H-pyrimidine-4,6-dione are preferred. Among the aminonaphthols are preferred those containing two or preferably only one sulpho group, more particularly H-acid, J-acid and xcex3-acid (the latter being particularly preferred).
B1 or B2 may be the radical of any coupling component Hxe2x80x94B1 or Hxe2x80x94B2 which may, in particular, be of the benzene, naphthalene, heterocyclic or open-chain methylene-active series, and suitably contains at least one substituent that activates the compound Hxe2x80x94B1 or Hxe2x80x94B2 or coupling, in particular an aromatically bound or enolic, optionally etherified hydroxy group or an optionally substituted amino group, so that the coupling reaction may take place in the corresponding activated position of the molecule Hxe2x80x94B1 or Hxe2x80x94B2.
Suitable coupling components Hxe2x80x94B1 or Hxe2x80x94B2 are, in particular, those of the following formulae 
wherein
R13 signifies hydrogen, xe2x80x94OR17 or NHR17,
R14 signifies xe2x80x94OR17 or xe2x80x94NHR17,
R15 signifies hydrogen, xe2x80x94SO3M, xe2x80x94SO2NR4R5, xe2x80x94COOM or xe2x80x94CONR4R5.
R16 signifies hydrogen, xe2x80x94SO3M, xe2x80x94SO2NR4R5, xe2x80x94COOM or xe2x80x94CONR4R5,
R17 signifies hydrogen, C1-4-hydrogen, C1-4-alkyl, Acxe2x80x2 or a radical of formula 
Acxe2x80x2 signifies the acyl radical of an aliphatic carboxylic acid,
Q3 signifies xe2x80x94COxe2x80x94, xe2x80x94SO2xe2x80x94 or the direct bond,
R18 signifies hydrogen, methyl, xe2x80x94NHxe2x80x94Ac, xe2x80x94COOM or xe2x80x94NO2 or, if in formula (bxe2x80x2) Q3 signifies xe2x80x94COxe2x80x94 or xe2x80x94SO2xe2x80x94, also xe2x80x94NH2,
R19 signifies xe2x80x94OH or xe2x80x94NH2,
R20 signifies hydrogen, C1-4-alkyl, C1-4-alkoxy, xe2x80x94OH, xe2x80x94NRxe2x80x3Rxe2x80x3xe2x80x2 or xe2x80x94NHxe2x80x94Ac,
R21 signifies hydrogen, C1-4-alkyl or C1-4-alkoxy,
Rxe2x80x3 and Rxe2x80x2xe2x80x3 independently, signify hydrogen, C1-2-alkyl or C2-3-hydroxy-alkyl,
R22 signifies hydrogen, sulphonaphthyl or a radical of formula 
G1 signifies hydrogen, halogen, methyl, methoxy or xe2x80x94COOM,
G2 signifies hydrogen, halogen, trifluoromethyl, nitril, nitro, xe2x80x94COOM, xe2x80x94SO3M or xe2x80x94SO2NR4R5,
R23 signifies C1-4-alkyl, phenyl, xe2x80x94COOM, xe2x80x94CONR4R5, xe2x80x94COOCH3 or xe2x80x94COOC2H5,
R24 signifies xe2x95x90O or xe2x95x90NH,
R25 signifies hydrogen, unsubstituted amino, phenylamino, sulphonaphthyl, open-chain C1-8-alkyl, C6-9-cycloalkyl, carboxy-(C1-4-alkyl), C2-4-alkyl substituted with hydroxy, methoxy, ethoxy or a sulpho group in one of the positions xcex2 to xcfx89, or a radical of formula (bxe2x80x3),
R26 signifies hydrogen, nitril, acetyl, xe2x80x94COOM, carbamoyl, xe2x80x94SO3M, pyridinio or 2-methyl-pyridinio,
R27 signifies hydrogen, hydroxy, methyl, carboxy, phenyl, sulphomethyl or carbamoyl,
R28 signifies hydroxy, primary amino, nitrilamino, thiol or a radical of formula 
R29 signifies hydroxy or primary amino,
R30 signifies hydroxy or primary amino,
R31 signifies hydrogen, methyl, chlorine, chloromethyl or chloroacetyl,
T signifies xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94 or the direct bond,
R32 signifies naphthyl, sulphonaphthyl, disulphonaphthyl or a radical of formula (bxe2x80x3),
R33 signifies C1-4-alkyl,
G3 signifies hydrogen, hydroxy, C1-4-alkoxy, xe2x80x94NHAc, xe2x80x94NH2, di-(C1-4-alkyl)-amino or carboxy-methylamino, and
G4 signifies hydrogen or methyl,
and, where in formula (b4) R26 stands for pyridinio or orthomethylpyridinio, any carboxy or sulpho group present in the molecule may be in the form of the anion xe2x80x94SO3xe2x80x94 or xe2x80x94COOxe2x80x94 to form the counter ion in the form of the inner salt.
The aliphatic acyl radical Acxe2x80x2 in the significance of R17 may be the radical of any aliphatic carboxylic acid as can be introduced by acylation, in particular of a C2-12-alkanoic primary monocarboxylic acid, preferably such as stated above for Ac, especially C2-4-alkanoyl, most preferably acetyl.
If R18 signifies xe2x80x94COOM, Q3 in formula (bxe2x80x2) signifies in particular xe2x80x94COxe2x80x94. If in formula (bxe2x80x2) Q3 signifies the direct bond, R18 preferably signifies hydrogen. If in formula (bxe2x80x2) Q3 signifies xe2x80x94SO2xe2x80x94, R18 preferably signifies methyl, acetylamino or xe2x80x94NH2. If in formula (bxe2x80x2) Q3 signifies xe2x80x94COxe2x80x94, R18 preferably signifies hydrogen or xe2x80x94NO2.
In formula (b1) xe2x80x94OR17 preferably signifies hydroxy and xe2x80x94NHR17 preferably signifies xe2x80x94NHR17xe2x80x2, where R17xe2x80x2 signifies hydrogen, methyl, acetyl or a radical of formula (bxe2x80x2). Preferably R14 signifies hydroxy or xe2x80x94NHR17xe2x80x2 and R13 signifies hydrogen or, where R14 signifies xe2x80x94OH, also a group xe2x80x94NHR17xe2x80x2. More preferably either R14 signifies hydroxy and R13 signifies hydrogen or xe2x80x94NHR17 or R14 signifies xe2x80x94NHR17xe2x80x2 and R13 signifies hydrogen, R15 preferably signifies hydrogen, xe2x80x94SO3M, xe2x80x94COOM or xe2x80x94CONH2. R16 preferably signifies hydrogen or xe2x80x94SO3M, more preferably hydrogen. Preferred coupling components of formula (b1) are those in which R13, R15 and R16 signify hydrogen and, in particular, R14 signifies hydroxy. Most preferably (b1) is xcex2-naphthol.
If in formula (b2) R20 signifies hydroxy, xe2x80x94NRxe2x80x3Rxe2x80x2xe2x80x3 or xe2x80x94NHxe2x80x94Ac, it is preferably in meta-position to R19 and R21 preferably signifies hydrogen. If R20 signifies C1-4-alkyl or C1-4-alkoxy it may be in any of the available positions ortho, meta and para to R19. More preferably R19 signifies hydroxy. Advantageously R21, signifies hydrogen.
Of the alkyl and alkoxy radicals with 1 to 4 carbon atoms, also in Hxe2x80x94B1 or Hxe2x80x94B2 the lower molecular ones are preferred (analogously as in Dxe2x80x94NH2), more specifically ethyl, methyl, ethoxy and methoxy. In the C2-3-hydroxyalkyl radicals the hydroxy group is preferably in xcex2position.
In formula (b3) R22 preferably signifies a radical of formula (bxe2x80x3). In formula (bxe2x80x3)xe2x80x94in the significance of R22xe2x80x94preferably at least one of G1 and G2 signifies hydrogen, more preferably G1. R23 preferably signifies C1-4-alkyl, more preferably methyl. R24 preferably signifies oxygen.
The open-chain C3-8-alkyl radicals in the significance of R25 may be linear or branched, if they contain 6 to 8 carbon atoms they are preferably branched; the cycloalkyl radicals in the significance of R25 are preferably cyclohexyl, which may be substituted with 1 to 3 methyl groups, more preferably it is unsubstituted cyclohexyl. The carboxy-substituted C1-4-alkyl group preferably is carboxymethyl or xcex2-carboxyethyl. The substituent (hydroxy, methoxy, ethoxy, sulpho) at the C2-4-alkyl, in the significance of R25, is preferably in xcex2-position. If R25 signifies a radical of formula (bxe2x80x3) G1 preferably signifies hydrogen and G2 preferably signifies carboxy, sulpho or trifluoromethyl. Preferred significances of R25 are hydrogen, a radical of formula (bxe2x80x3), C1-8-alkyl, C2-3-hydroxyalkyl and C6-9-cycloalkyl.
R26 preferably signifies hydrogen, a sulpho group or one of the stated nitrogen-containing substituents.
R27 preferably has a significance other than hydrogen, more preferably methyl.
In formula (b5) preferably at least one of R29 and R30 signifies hydroxy, more preferably both R29 and R30 signify hydroxy groups.
If in formula (b5) R28 signifies a radical of formula (bxe2x80x3xe2x80x2), xe2x80x94NHxe2x80x94Q3xe2x80x94 preferably signifies a group xe2x80x94NHxe2x80x94SO2xe2x80x94.
In formula (b6) the hydroxy group preferably is in position 8. If R31 is other than hydrogen it is preferably in position para to the 8-positioned hydroxy group. R31 preferably signifies hydrogen or methyl, more preferably hydrogen.
In formula (b7) T preferably signifies xe2x80x94NHxe2x80x94. More preferably R32 is unsubstituted phenyl and R33 is preferably methyl.
The coupling component radical xe2x80x94B1 or xe2x80x94B2 preferably contains up to three cycles (homocyclic rings, heterocyclic rings and optionally a cycloaliphatic ringxe2x80x94a naphthalene radical being calculated as two cycles), more preferably xe2x80x94B1 or xe2x80x94B2 contain each one or two of such cycles.
The coupling components Hxe2x80x94B1 and Hxe2x80x94B2 preferably correspond to formula (b1), (b2), (b3) and/or (b7) or are preferably mixtures of (b1) with one of (b2), (b3) or (b7), e.g. in the molar ratio of 1/9 to 9/1, preferably 3/7 to 7/3.
The bis-diazo component radicals W1 are bicyclic, in particular they contain two benzenic rings linked to each other over a heteroatomic bridge. They derive from corresponding bis-diazo components containing as a substituent at one of the two rings a primary diazotizable amino group and as a substituent at the other benzenic ring a primary diazotizable amino group or a substituent convertible into such a primary amino group, in particular a nitro group reducible to primary amino or an acylated amino group hydrolyzable to primary amino; more preferably this substituent is, however, primary amino. As bis-diazo components from which W1 derives come, in particular, into consideration those of the formula 
wherein
T1 signifies a heteroatomic bridging member, in particular xe2x80x94SO2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94SO2xe2x80x94NHxe2x80x94, xe2x80x94SO2xe2x80x94NHxe2x80x94SO2xe2x80x94, xe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94, or a methylene bridge.
Rx signifies primary amino, acetylamino or nitro, and
z signifies 0 or 1.
In formula (Aa1) Rx preferably signifies primary amino.
T1 preferably signifies xe2x80x94SO2NHxe2x80x94, xe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94NHxe2x80x94 or xe2x80x94SO2NHxe2x80x94SO2xe2x80x94, among which xe2x80x94NHxe2x80x94 and especially xe2x80x94SO2xe2x80x94NHxe2x80x94 are particularly preferred.
R2 in formula (Aa1) preferably signifies hydrogen.
Where T1 signifies xe2x80x94NHxe2x80x94 z preferably signifies 1. Where T1 signifies xe2x80x94COxe2x80x94NHxe2x80x94 or xe2x80x94SO2xe2x80x94NHxe2x80x94 the xe2x80x94NHxe2x80x94 group thereof is preferably linked to the benzenic ring bearing the substituent Rx. Where T1 signifies a bridging group containing a xe2x80x94SO2xe2x80x94 or xe2x80x94COxe2x80x94 group z preferably signifies 0.
The substituent Rx, in particular the primary amino group, may be in position meta, or preferably, para to T1.
The compounds of formula (VI) preferably correspond to the above formula (Aa1) wherein Rx signifies primary amino, which is more preferably in para position to T1.
In formula (II) Q1 preferably signifies xe2x80x94SO2xe2x80x94; Q2 preferably signifies the direct bond.
Among the tetrakisazo dyes of the invention are preferred those in which Z signifies a radical of formula (xcex1), especially those of formula (Ib), and particularly preferred are also their mixures with trisazo dyes of formula (X).
The diazotization and coupling reactions may be carried out in a manner conventional per se. Diazotization may e.g. be carried out with a nitrite (preferably sodium nitrite) in acidic aqueous medium (preferably in the presence of hydrochloric acid) and at low temperatures, e.g. in the range of xe2x88x925xc2x0 C. to +10xc2x0 C., preferably 0 to 5xc2x0 C. The coupling reaction of the diazonium compounds to the respective coupling components is advantageously carried out at temperatures in the range of xe2x88x925xc2x0 C. to +30xc2x0 C., preferably below 25xc2x0 C., more preferably in the range of 0 to 10xc2x0 C. The coupling of the diazo compound of an amine of formula (VIII) to a middle component of formula (IX) may be carried out under distinctly acidic to strongly basic pH-conditions, e.g. at a pH in the range of 4 to 12, preferably 5 to 11. The selective coupling of a bisdiazo compound of a diamine of formula (II) or (VI) at one side to the 3-position of a compound of formula (III) is suitably carried out under distinctly acidic conditions, e.g. at a pH in the range of 1 to 5, preferably by adding an aqueous solution of a compound of formula (III) of a nearly neutral pH (e.g. pH in the range of 6 to 8, preferably 6.5 to 7.5) into the acidic solution, in which the diazotization has been carried out and that contains the diazonium compound.
The coupling of the monoazodiazo compound to a coupling component Hxe2x80x94B1 or Hxe2x80x94B2 may be carried out at any pH as suitable for coupling to the respective coupling component, preferably at pH values below 10, in particular in the range of 4 to 8.5, more preferably under nearly neutral conditions, in particular at pH-values in the range of 6 to 7.5 and at temperatures, e.g. in the range of xe2x88x925xc2x0 C. to +30xc2x0 C., preferably 0 to 25xc2x0 C. The coupling of a diazo compound of an amine of formula (V) to the 6-position of a compound of formula (IV) is preferably carried out under mildly basic to nearly neutral pH-conditions, e.g. at a pH in the range of 6 to 9, preferably 6.5 to 8 and under temperatures preferably in the range of 0 to 25xc2x0 C. These pH and temperature conditions are also suitable for the selective coupling of the bisdiazocompound of a bisamine of formula (II) or (VI) at one side to the 6-position of a disazo compound of formula (VII). The coupling of the trisazodiazocompound to a coupling component Hxe2x80x94B1 or Hxe2x80x94B2 may be carried under conditions as described above for the coupling of the monoazodiazo compound. By using a suitable base for pH-adjustment (preferably alkali metal hydroxide, e.g. sodium hydroxide or potassium hydroxide, more preferably sodium hydroxide), the dyes may be obtained in a suitable salt form of high hydrosolubility. If desired, they may be obtained in another salt form, e.g. by precipitation by means of acidification and then conversion to another salt form by addition of a suitable base.
The synthetized dyes may be purified, if desired, in any manner conventional per se, e.g. by precipitation (e.g. by salting out or by acidification with a strong mineral acid) and filtration and optionally re-precipitation and filtration, and/or by microfiltration and, optionally, ultra-filtration. Where desired, the dye solution may be further purified and/or concentrated by means of suitable membrane filtrations. The purified dye solutions may be dried to dye-powder or -granulate.
The dye may, upon isolation or dialysis, be blended with suitable blending agents conventional per se, e.g. alkali metal salts (sodium carbonate, sodium sulphate) non-electrolyte blending agents (mainly oligosaccharides, e.g. dextrine) or/and with surfactants (e.g. as suitable as wetting agents), in particular non-ionic and/or anionic surfactants. There may e.g. be mentioned hydrocarbon sulphonates, sulphonated castor oil, sulphosuccinates, lignin sulphonate, hydrophilic polysaccharide derivatives, ethoxylated alkylphenols or fatty alcohols. If a surfactant is employed the weight ratio of the surfactant to the dye is advantageously in the range of 5:95 to 40:60. If desired, especially if the composition contains a surfactant, as indicated above, it may be formulated with water as a liquid concentrated dye-composition, preferably with a dry-substance content in the range of 10 to 70%, more preferably 20 to 50% by weight, referred to the weight of the composition.
The dyes of the invention are, in general, of dark hues, in particular ranging from green to red hues, e.g. bluish black, reddish black or greenish black, and/or deep black.
The tetrakisazo dyes of the invention are anionic dyes and are suitable for dyeing substrates dyeable with anionic dyes.
Any substrate that is dyeable with anionic dyes is suitable as a substrate that may be dyed with the azo dyes of the invention; these include natural and regenerated cellulose, polyurethanes, basically modified high polymers (e.g. basically modified polypropylene), natural or synthetic polyamides or anodized aluminium, in particular, however, leather substrates. The substrate to be dyed may be in any conventional form, e.g. in the form of loose fibers, filaments, yarns, woven or knitted goods, non-woven webs, carpets, half-ready-made and ready-made soft goods and tanned leather or pelts. The dyes may be employed in any desired concentration up to the saturation of the substrate. The dyeing may be carried out by any conventional methods that are suitable for the substrate to be dyed, e.g. by exhaustion or impregnation methods (e.g. padding, spraying, foam application or application with a roller, or printing), preferably from aqueous medium; for synthetic substrates, the dye may optionally also be incorporated into the synthetic mass. Paper may be dyed in the pulp, or after sheet formation.
The dyes of the invention are, however, mainly suitable for the dyeing of leather and pelts.
Any kinds of leather which are conventionally dyed from aqueous medium are suitable, particularly grain leather (e.g. nappa from sheep, goat or cow and box-leather from calf or cow), suede leather (e.g. velours from sheep, goat or calf and hunting leather), split velours (e.g. from cow or calf skin), buckskin and nubuk leather; further also woolen skins and furs (e.g. fur-bearing suede leather). The leather may have been tanned by any conventional tanning method, in particular vegetable, mineral, synthetic or combined tanned (e.g. chrome tanned, zirconyl tanned, aluminium tanned or semi-chrome tanned). If desired, the leather may also be re-tanned; for re-tanning there may be used any tanning agent conventionally employed for re-tanning, e.g. mineral, vegetable or synthetic tanning agents |e.g. chromium, zirconyl or aluminium derivatives, quebracho, chestnut or mimosa extracts, aromatic syntans, polyurethanes, (co) polymers of (meth)acrylic acid compounds or melamine/, dicyanodiamide/and/or urea/formaldehyde resins|. Thus leathers of very high to very low affinity for anionic dyes may be used.
The leathers may be of various thicknesses, thus, there may be used very thin leathers, such as book-binder""s leather or glove-leather (nappa), leather of medium thickness, such as shoe upper leather, garment leather and leather for handbags, or also thick leathers, such as shoe-sole leather, furniture leather, leather for suitcases, for belts and for sport articles; hear-bearing leathers and furs may also be used. After tanning (in particular after a re-tanning) and before dyeing, the pH of the leather is advantageously set to values in the range of 4 to 8 (the leather is xe2x80x9cneutralizedxe2x80x9d); depending on the kind of the leather, there may be chosen an optimum pH range, e.g. for grain leather pH values in the range of 4 to 6, for suede leather and split velours and for very thin leathers pH-values in the range of 4.5 to 8, for intermediately dried suede leathers and intermediately dried split velours the pH may range in the scope of 5 to 8. For the adjustment of the pH-value of the leather there may be employed conventional assistants; for tanned leather of acidic character the pH may be adjusted by addition of suitable bases, e.g. ammonia, ammonium bicarbonate or alkali metal salts of weak acids, e.g. sodium formate, sodium acetate, sodium bicarbonate, sodium carbonate or sodium sulphite, of which sodium formate and sodium bicarbonate are preferred. Sodium carbonate and sodium bicarbonate are usable in particular as second bases for the exact adjustment of the superficial pH-value of the leather. Mineral tanned leather may, if desired, also be masked, e.g. with alkali metal formate, oxalate or polyphosphate or e.g. with titanium/potassium oxalate.
The dyeing may be carried out in a manner known per se suitably in an aqueous medium and under conventional temperature and pH conditions, in particular in the temperature range of 20 to 80xc2x0 C., preferably 25 to 70xc2x0 C., milder temperature conditions, in particular in the range of 25 to 40xc2x0 C., being preferred for the achievement of deeper penetrations and for the dyeing of wool-bearing skins and furs. The pH-values of the dye-bath may, in general, range broadly, mainly from pH 8 to pH 3; in general the dyeing may be advantageously begun at higher pH-values and concluded at lower pH-values. Preferably the dyeing is carried out at pH-values xe2x89xa74, in particular in the pH-range of 8 to 4, and for the conclusion of the dyeing procedure the pH-value is lowered (e.g. by addition of an acid conventional in the leather dyeing technique such as acetic acid or formic acid) preferably to values in the range between 4 and 3. The dye concentration may range broadly, if desired, up to the saturation degree of the substrate, e.g. up to 5%, referred to the wet weight of the substrate. The dyeing may be carried out in one or more stages, e.g. in two stages, optionally with insertion of charge reversal of the substrate by means of conventional cationic assistants.
The dyes of the invention may, if desired, be employed in combination with conventional dyeing assistants, mainly non-ionic or anionic products (in particular surfactants, preferably hydrophilic polysaccharide derivatives, polyoxyethylated alkylphenols or alcohols, lignosulphonates or sulpho group-containing aromatic compounds).
A fatting may, if desired, be carried out before and/or after the dyeing process, in particular also in the same liquor. For fatting after the dyeing process the fatting agent is advantageously added before the pH of the liquor is lowered, preferably to values between 3 and 4.
For the fatting (in particular fat-liquoring) step there may be used any conventional natural animal, vegetable or mineral fat, fat oil or wax, or chemically modified animal or vegetable fat or oil, which include in particular tallow, fish oils, neats-foot oil, olive oil, castor oil, rapeseed oil, cottonseed oil, sesame oil, corn oil and Japanese tallow, and chemically modified products thereof (e.g. hydrolysis, transesterification, oxidation, hydrogenation or sulphonation products), bees-wax, Chinese wax, carnauba wax, montan wax, wool fat, birch oil, mineral oils with boiling range within 300 and 370xc2x0 C. (particularly the so-called xe2x80x9cheavy alkylatesxe2x80x9d), soft paraffin, medium paraffin, vaseline and methyl esters of C14-22-fatty acids; and synthetic leather fatting agents, including esters, in particular partial esters of polybasic acids (e.g. phosphoric acid) with optionally oxyethylated fatty alcohols. Of the above mentioned the methyl ester, the sulphonation products and the phosphoric acid partial esters are particularly preferred. By the term xe2x80x9csulphonationxe2x80x9d for the fatting agents, there is meant generally the introduction of the sulpho group including also the formation of a sulphato group (=xe2x80x9csulphatingxe2x80x9d) and the introduction of a sulpho group by reaction with a sulphite or SO2 (=xe2x80x9csulphitingxe2x80x9d).
A conventional leather softener, in particular a cationic leather softener may, if desired, be applied in a final step, particularly if fatting has been carried out with a sulphonated fat-liquoring agent.
The treated substrate may then be further treated in conventional manner, e.g. rinsed or washed, drained, dried and cured.
According to the invention there may be obtained azodyes that display, even with a relatively low number of hydro-solubilizing substituents in W1, W2, D, B1 or B2, a high solubility in water, especially where the anionic dyes are in alkali metal salt form; they are distinguished by their stability to electrolytes (in particular inorganic ions), specifically also to bases and acids, and are also distinguished, especially on leather, by their build-up and a high degree of insensitivity to variations of the affinity of the leather towards anionic dyes, very level dyeings of outstanding penetration and high colour-yield being obtainable. In these leather-dyeing properties the dyes of formulae (Ic) and especially (Ib) excel over those of formula (Ia) and are, thus, preferred. According to a particular feature of the invention and with a view to these properties, they may advantageously be employed also in a form substantially free of other elektrolytes, as obtainable by dialysis.
The dyeings, particularly on leather, have excellent fastness properties, for example wet-fastnesses, fastness to rubbing, light-fastness and stability to PVC-migration. They are readily combinable with other dyes, in particular such with similar tinctorial behavior. There may be obtained very level, intense, fine dyeings, grain side and velours side being very evenly dyed, the shade of the dyeings on different kinds of leather being equal or very similar; in admixture with corresponding compatible dyes with which the dyes of the invention are combinable, in particular with the above trisazo dyes of formula (X), there may also be obtained very intense and regular dyeings of high yield and optimum fastnesses. By the choice of the substituents some of the properties of the dyes (e.g. solubility, shade, build-up, penetration, levelness etc.) may be varied accordingly. The polyazodyes of the invention, especially the preferred ones, are also well combinable with trisazo or other tetrakisazo dyes, there being obtainable very homogeneous shades and penetrations and regular dyeings of optimum fastnesses, also light fastness.