Monoazo dyestuffs useful for dyeing and printing hydrophobic fibers have the formula ##STR1## in which R.sup.1 denotes alkyl having 1 to 3 carbon atoms, R.sup.2 and R.sup.3 independently of one another denote alkyl having 2 to 5 carbon atoms and R.sup.4 denotes methyl or ethyl.

The present invention relates to useful monoazo dyestuffs of the general 
formula I 
##STR2## 
in which R.sup.1 denotes alkyl having 1 to 3 C atoms, R.sup.2 and R.sup.3 
independently of one another denote alkyl having 2 to 5 C atoms and 
R.sup.4 denotes methyl or ethyl. 
The invention also relates to mixes of dyestuffs of the general formula I 
and to the preparation of these dyestuffs and their mixtures and their use 
for dyeing hydrophobic fibre materials. 
The alkyl radical R.sup.1 having 1 to 3 C atoms can denote methyl, ethyl, 
n-propyl or i-propyl. Preferred radicals for R.sup.1 are methyl and ethyl. 
The alkyl radicals R.sup.2 and/or R.sup.3 can be straight-chain or 
branched. Examples of the alkyl radicals R.sup.2 and/or R.sup.3 having 2 
to 5 C atoms are: ethyl, n-propyl, i-propyl, n-butyl, i-butyl, 
tert.-butyl, sec.-butyl, n-pentyl, pent-2-yl and pent-3-yl. 
The alkyl radicals R.sup.2 and/or R.sup.3 preferably have 2 to 4 C atoms. 
Preferred radicals for R.sup.2 and/or R.sup.3 are ethyl, and in particular 
n-propyl, i-propyl, n-butyl, i-butyl and sec.-butyl. R.sup.4 preferably 
represents methyl. The radicals R.sup.2 and R.sup.3 are preferably 
identical. 
The sum of the C atoms in the radicals R.sup.1, R.sup.2 and R.sup.3 is 
preferably 5 to 11, particularly preferably 6 to 10. Preferred 
combinations for R.sup.1, R.sup.2 and R.sup.3 are CH.sub.3 /C.sub.2 
H.sub.5 /C.sub.2 H.sub.5 ; CH.sub.3 /n-pentyl/n-pentyl; CH.sub.3 
/pent-2-yl/pent-2-yl; and CH.sub.3 /pent-3-yl/pent-3-yl. 
Particularly preferred combinations for R.sup.1, R.sup.2 and R.sup.3 are 
CH.sub.3 /n-butyl/n-butyl; CH.sub.3 /i-butyl/i-butyl; CH.sub.3 
/sec.-butyl/sec.-butyl; C.sub.2 H.sub.5 /n-propyl/n-propyl; C.sub.2 
H.sub.5 /i-propyl/i-propyl. 
Especially preferred combinations for R.sup.1, R.sup.2 and R.sup.3 are 
CH.sub.3 /n-propyl/n-propyl; CH.sub.3 /i-propyl/i-propyl; C.sub.2 H.sub.5 
/C.sub.2 H.sub.5 /C.sub.2 H.sub.5. 
Preferred dyestuffs of the formula I are those with preferred radicals 
R.sup.1, R.sup.2 and R.sup.3. 
Particularly preferred dyestuffs are those with particularly preferred 
combinations of R.sup.1, R.sup.2 and R.sup.3 and where R.sup.4 is methyl. 
Especially preferred dyestuffs are those with especially preferred 
combinations of R.sup.1, R.sup.2 and R.sup.3 and where R.sup.4 is methyl. 
The dyestuffs of the formulae II and III 
##STR3## 
which are similar to the dyestuffs according to the invention are already 
known and are described in German Patent 1,544,563. 
However, it has now been found, surprisingly, that the dyestuffs according 
to the invention are superior to these dyestuffs, especially in 
application fastness properties, such as pH sensitivity, reduction 
sensitivity and fastness to prolonged boiling, as well as in tinctorial 
strength, and have very good fastness properties in use, such as fastness 
to thermomigration, fastness to thermofixing, fastness to water and 
fastness to light. They can moreover also be employed in alkaline 
discharge resist printing. 
The dyestuffs according to the invention have a greenish-tinged blue shade 
and they are therefore outstandingly suitable for toning reddish-tinged 
blue dyestuffs, for example those of the formula IV 
##STR4## 
such as are described, for R.sup.4 =R.sup.5 =CH.sub.3, for example, in 
British Patent Specification 1,184,825, to give neutral blue shades. 
The dyestuffs according to the invention are preferably prepared by a 
procedure in which an azo dyestuff of the formula V 
##STR5## 
wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the meanings already 
given and Hal denotes a halogen atom, such as chlorine or, in particular, 
bromine, is subjected to a nucleophilic replacement reaction in a manner 
which is known per se, for example in accordance with the instructions in 
German Offenlegungsschrift 1,809,920, German Offenlegungsschrift 
1,809,921, British Patent Specification 1,184,825, German Auslegeschrift 
1,544,563, German Offenlegungsschrift 2,310,745, German Auslegeschrift 
2,456,495, German Auslegeschrift 2,610,675, German Offenlegungsschrift 
2,724,116, German Offenlegungsschrift 2,724,117, German 
Offenlegungsschrift 2,834,137, German Offenlegungsschrift 2,341,109, U.S. 
Pat. No. 3,821,195, German Offenlegungsschrift 2,715,034 or German 
Offenlegungsschrift 2,134,896, the cyanide ion CN.sup.- being employed as 
a nucleophilic agent. In this reaction, Hal in the dyestuff of the formula 
V is replaced by CN. 
Solvents which are employed for the replacement reaction are inert organic 
solvents, such as, for example, nitrobenzene or glycol or diglycol 
monomethyl or monoethyl ether, or mixtures of such solvents with one 
another and with tertiary organic nitrogen bases, and dipolar aprotic 
solvents, such as, for example, N-methylpyrrolidone, pyridine, 
dimethylformamide, dimethylsulphoxide or dicyano-dialkylthio ethers. Water 
or aqueous systems consisting of water and a water-immiscible organic 
solvent, such as, for example, nitrobenzene, preferably in the presence of 
a wetting or dispersing agent or a known phase transfer catalyst, or of 
water and a water-soluble inert organic solvent, such as ethylene glycol 
or dimethylformamide, are furthermore suitable as the medium for the 
replacement reaction. 
The presence of organic basic nitrogen compounds, such as, for example, 
pyridine and pyridine bases, also have a favourable effect on the 
replacement reaction. 
The reaction temperatures for the replacement reaction are normally between 
20.degree. and 150.degree. C. 
The nucleophilic agent CN.sup.- is fed to the reaction in the form of a 
metal cyanide, which is complex if appropriate, such as, for example, an 
alkali metal or alkaline earth metal cyanide, zinc cyanide or an alkali 
metal cyano-zincate or ferrate, but preferably in the form of copper-I 
cyanide or a system which forms copper-I cyanide. The use of a combination 
of alkali metal cyanide and copper-I cyanide, in which the weight ratio of 
alkali metal and copper salt can be varied within wide limits, has proved 
particularly suitable. 
The customary range for the weight ratio of alkali metal cyanides/copper-I 
cyanide is 5:95 to 95:5. Positive mutual influencing of the components can 
also still be detected outside these limits. It is of course also possible 
for the copper-I cyanide in turn to be replaced by a system which forms 
copper-I cyanide, such as, for example, a combination of alkali metal 
cyanide with another copper salt, preferably a copper-I salt, such as, for 
example, a copper-I halide. 
The dyestuffs of the formula V required for preparation of the dyestuffs 
according to the invention can be prepared by a procedure in which a 
diazonium compound of an aromatic amine of the general formula VI 
##STR6## 
wherein Hal has the meaning already given, is coupled with a coupling 
component of the general formula VII 
##STR7## 
wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the abovementioned 
meanings, in a manner which is known per se. 
The solutions of the diazonium compounds are obtained from the amines of 
the general formula VI in a manner which is known per se by the action of 
nitrous acid or other systems which form nitrozonium ions, in a mineral 
acid or a mineral acid aqueous medium or a lower alkane carboxylic acid, 
such as, for example, formic acid, acetic acid or propionic acid, or 
mixtures thereof, at temperatures from -15.degree. C. to 40.degree. C. 
The coupling is likewise carried out in a manner which is known per se by 
combining the resulting solution of the diazonium compound with a solution 
of the coupling component at temperatures from 0.degree. to 40.degree. C., 
preferably 0.degree. to 25.degree. C., in a suitable solvent, such as, for 
example, an alkanol having 1 to 4 C atoms or dimethylformamide, or 
preferably in water acidified with sulphuric acid, hydrochloric acid or 
phosphoric acid, or an optionally aqueous lower alkane carboxylic acid or 
a lower alkane carboxylic acid mixture. 
In some cases, it may be advantageous to buffer the pH during the coupling, 
for example by addition of sodium acetate. The coupling has ended after a 
few hours and the dyestuff of the formula V can be isolated and dried in 
the customary manner. 
The coupling components of the formula VII required can be prepared from 
known commercial products by known processes. 
Another process for the preparation of the dyestuffs according to the 
invention comprises acylation of dyestuffs of the formula VIII 
##STR8## 
wherein R.sup.1 and R.sup.4 have the meanings given, with known acylating 
agents of the formula 
EQU X--COR.sup.2 or X--COR.sup.3 
wherein X is a radical which can be split off, taking the bonding electron 
pair and R.sup.2 and R.sup.3 have the abovementioned meanings. The 
acylating agents are reacted derivatives of the carboxylic acids of the 
formulae 
EQU R.sup.2 COOH or R.sup.3 COOH 
such as, for example, carboxylic acid chlorides (X=Cl) or carboxylic acid 
anhydrides (X=R.sup.2 COO-- or X=R.sup.3 COO--). 
It is advantageous to carry out the acylation reaction in a solvent or 
diluent in order to moderate the reaction. All the organic solvents which 
cannot react with the acylating agents are suitable. Aromatic 
hydrocarbons, such as benzene, toluene or xylene, are chiefly used as 
solvents, diluents or dispersing agents, it being advantageous to carry 
out the acylation in the presence of an acid-trapping agent, such as, for 
example, a tertiary organic amine base. Acylations of the type mentioned 
can also be carried out in the presence of pyridine or pyridine 
derivatives as solvents. In this case, the solvent itself acts as the 
acid-trapping agent. Acylation with alkane carboxylic acid anhydrides is 
possibly carried out in the excess alkane carboxylic acid anhydride itself 
or in the corresponding alkane carboxylic acid as the solvent. The 
acylation of the dyestuffs of the formula VIII can be carried out at 
temperatures between normal room temperature and temperatures up to 
150.degree. C. At least 2 mol of the acylating agent are as a rule 
employed per mol of the dyestuff of the formula VIII. 
The dyestuffs of the formula VIII required for this preparation process can 
be prepared by a process in which a diazonium compound of an aromatic 
amine of the general formula VI 
##STR9## 
is coupled with a coupling component of the general formula IX 
##STR10## 
wherein Hal, R.sup.1 and R.sup.4 have the abovementioned meanings, in a 
manner which is known per se and the halogen atom Hal is then replaced by 
the cyano radical. 
The diazotization of the aromatic amine of the formula VI and the coupling 
of the resulting diazonium compounds to the amine of the formula IX are 
carried out within the conditions which have already been described in 
detail above for the preparation of the dyestuffs of the formula V. The 
subsequent replacement of the halogen atom Hal by cyano is also carried 
out within the conditions described above for the preparation of the 
dyestuffs of the formula I according to the invention. 
Dyestuff mixtures according to the invention consist of two or more 
dyestuffs of the formula I in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 
have the abovementioned meanings Mixtures of preferred dyestuffs of the 
formula I are preferred, and of these those which differ only in the 
meaning of the radical R.sup.1 are particularly preferred. 
The ratio of the various dyestuffs of the general formula I in the dyestuff 
mixtures according to the invention can vary within relatively wide 
limits, and the dyestuffs can be in the form of crystal mixtures or 
entirely or partly in the form of mixed crystals. The minimum amount by 
weight of one component is in general 10%, and its maximum amount by 
weight is 90%. In the case of dyestuff mixtures which consist only of two 
dyestuffs of the general formula I, a weight ratio of 70:30 to 30:70 is 
preferred, that is to say the amount by weight of one dyestuff is 30 to 
70%. 
The dyestuff mixtures according to the invention can be prepared by various 
processes, thus, for example: 
1) By mixing at least two separately prepared and finished individual 
dyestuffs of the formula I. 
2) By mixing separately prepared individual dyestuffs which have not been 
finished and finishing them together. 
3) By mixing the starting materials of the general formulae V; VI and VII; 
VIII; or VI and IX, and further reacting them together as described above. 
If, for example, a mixture of two or more dyestuffs of the formula V which 
differ from one another in respect of R.sup.1 and/or R.sup.2 and/or 
R.sup.3 and/or R.sup.4 is employed instead of an individual dyestuff of 
the formula V in the process described above for replacement by cyano, the 
corresponding mixture of dyestuffs of the formula I according to the 
invention is obtained. 
The mixture of the dyestuffs of the formula V which is employed here can of 
course in turn either be obtained by mixing separately prepared dyestuffs 
of the formula V, or it can be prepared by coupling of the diazonium 
compound of an amine of the formula VI to a corresponding mixture of 
coupling components of the formula VII which differ from one another in 
respect of R.sup.1 and/or R.sup.2 and/or R.sup.3 and/or R.sup.4. 
It is also possible in the acylation process described above for a mixture 
of two or more dyestuffs of the formula VIII which differ from one another 
in respect of R.sup.1 and/or R.sup.4 to be acylated instead of an 
individual starting dyestuff of the formula VIII. Another variant of this 
process is the acylation of a dyestuff or a mixture of two or more 
dyestuffs of the formula VIII which differ in respect of R.sup.1 and/or 
R.sup.4 with a mixture of two or more acylating agents which differ from 
one another in respect of R.sup.2 and R.sup.3. 
The dyestuffs and dyestuff mixtures according to the invention are 
outstandingly suitable, individually or as a mixture with other dispersed 
dyestuffs, for dyeing and printing hydrophobic synthetic materials. 
Possible hydrophobic synthetic materials are, for example: cellulose 21/2 
acetate, cellulose triacetate, polyamides and high molecular weight 
polyesters. The dyestuffs according to the invention are preferably 
employed for dyeing and printing materials of high molecular weight 
polyesters, in particular those based on polyethylene glycol 
terephthalates or mixtures thereof with naturally occurring fibre 
materials, or of materials of cellulose triacetate. 
The hydrophobic synthetic materials can be in the form of sheet-like or 
thread-like structures and can be processed, for example, to yarns or 
woven, knitted or meshed textiles. The fibre goods mentioned can be dyed 
with the dyestuffs or dyestuff mixtures according to the invention in a 
manner which is known per se, preferably from aqueous suspension, if 
appropriate in the presence of carriers, at between 80.degree. and about 
110.degree. C. by the exhaustion process or by the HT process in a dyeing 
autoclave at 110.degree. to 140.degree. C., and by the so-called 
thermofixing process, in which the goods are padded with the dye liquor 
and then fixed at about 80.degree. to 230.degree. C. Printing of the 
materials mentioned can be carried out in a manner which is known per se 
by incorporating the dyestuffs or dyestuff mixtures according to the 
invention into a printing paste and treating the goods printed with this 
paste with HT steam, pressurized steam or dry heat at temperatures between 
80.degree. to 230.degree. C., if appropriate in the presence of a carrier, 
in order to fix the dyestuff. Very deep greenish-tinged blue dyeings and 
prints with very good fastness properties, in particular very good 
fastness to light, thermofixing, thermomigration and washing, and above 
all a very good M+S fastness (C4A washing), are obtained in this manner. 
The dyestuffs or dyestuff mixtures according to the invention are also 
suitable for dyeing the abovementioned hydrophobic materials from organic 
solvents by the methods known for this, and for bulk dyeing as well as for 
alkaline discharge resist printing. 
If a textile material containing exclusively hydrophobic fibres or only the 
hydrophobic fibre content of a textile blend is to be coloured by alkaline 
discharge resist printing, the procedure takes place in a manner which is 
known per se by padding the textile materials with dye liquors or printing 
them with printing pastes which contain one or more dyestuffs of the 
formula I in addition to the known customary dyeing auxiliaries, such as, 
for example, dispersing agents, wetting agents, foam suppressants or 
padding auxiliaries and printing thickeners. Padded fabric webs are 
squeezed off onto a liquor pick-up of 50 to 120%. After this first padding 
or printing process, the goods can be dried or superficially dried, or 
further processing can be carried out "wet-in-wet" without any separate 
drying operation. The fabric webs are then printed with a discharge resist 
printing paste which contains, as the discharge agent, a base which 
produces a pH of at least 8 in 5% strength aqueous solution, and the known 
additives customary in printing pastes for textile printing, in particular 
thickening agents. 
The operation, mentioned above as the first process step, of padding or 
printing with a dye liquor or printing paste and the printing, mentioned 
as the second step, with the discharge resist printing paste can also be 
interchanged. In this case, after the discharge resist printing paste has 
been printed on, the textile material is over-padded with the dye liquor 
for the background dyeing, or overprinted with the printing paste. This 
sequence can also be carried out "wet-in-wet", or the textile material can 
be dried superficially or dried after being printed with the discharge 
resist paste. The padded and printed fabric webs are then subjected to 
heat treatment at between 100.degree. and 230.degree. C. In the lower 
temperature range from about 100.degree. to 110.degree. C., heating is 
preferably by superheated steam. For heat treatments carried out between 
160.degree. and 230.degree. C., hot air is preferably used as the heat 
transfer medium. After the heat treatment, which results in fixing of the 
dispersed dyestuffs and destruction of the dyestuffs of the formula I at 
the points printed with the discharge resist printing paste, the textiles 
are after-treated, rinsed hot and cold and dried, in the manner customary 
for polyesters. A particular embodiment of the discharge printing process 
comprises a procedure in which the padding liquor also contains, in 
addition to dyestuffs of the formula I, those which are stable towards 
alkali and thus are not destroyed by the alkaline discharge resist 
printing pastes to be employed. If the procedure is otherwise as described 
above, multi-coloured designs are obtained. As already described above, 
another embodiment of the process comprises a procedure in which the dye 
liquor of the formula I is not applied to the total fabric by padding with 
a padding liquor but is likewise printed on to the fabric in the form of 
printing pastes. 
Fixing and finishing of the textile prints is then carried out as already 
described above. It is also possible in this process to add dyestuffs 
which are resistant to alkalis to the printing pastes printed on. In this 
case also, multi-coloured designs are obtained. 
A large number of bases which the discharge resist printing paste contains 
as discharge agents and which bring about a pH of at least 8 in 5% 
strength aqueous solution are known. Examples of such bases are the 
hydroxides of the alkali and alkaline earth metals, salts of alkaline 
earth and alkali metals with weak organic or inorganic acids, such as, for 
example, alkali metal acetates, alkali metal carbonates or bicarbonates or 
tri-alkali metal phosphates, ammonia or aliphatic amines, such as, for 
example, triethyl-, tripropyl- or tributylamine, ethanolamine, dimethyl- 
or diethyl ethanolamine, diethanolamine, methyl-, ethyl- or 
propyldiethanolamine or triethanolamine. Alkaline earth metal hydroxides, 
such as, for example, calcium hydroxide, alkali metal hydroxides, such as, 
for example, sodium hydroxide or potassium hydroxide, or alkali metal 
salts of weak inorganic acids, such as, for example, sodium carbonate, 
trisodium phosphate or sodium silicate or potassium silicate, are usually 
employed as the bases. Sodium hydroxide or potassium hydroxide or, in 
particular, sodium carbonate, potassium carbonate, sodium bicarbonate or 
potassium bicarbonate is preferably used as the base in the discharge 
resist printing pastes. Mixtures of various bases can also be used. The 
concentration of the base in the discharge resist printing pastes is 
advantageously 25 to 250 g/kg, preferably 50 to 130 g/kg. The discharge 
resist printing pastes contain, in addition to the bases mentioned, the 
additives usually contained in textile printing pastes, in particular 
thickening agents, such as, for example, alginates, starch products, 
synthetic polymeric thickening agents, mineral oils, hydrotropic 
substances, such as, for example, urea, and additives which promote the 
wetting, penetration and dyestuff uptake. The presence of nonionogenic 
detergents, which are advantageously contained in the discharge resist 
printing pastes, such as, for example, glycerol and/or polyglycols, such 
as polyethylene glycol having an average molecular weight of 300 to 400, 
is particularly advantageous for the discharge operation. 
The dyestuffs or dyestuff mixtures according to the invention should be 
present in the dye liquors and printing pastes employed in the above 
application in the finest possible division. 
The dyestuffs are finely divided in a manner which is known per se by 
suspending the dyestuff obtained in the manufacture in a liquid medium, 
preferably in water, together with dispersing agents and exposing the 
mixture to the action of shearing forces, the dyestuff particles 
originally present being ground mechanically to the extent that an optimum 
specific surface area is achieved and the sedimentation of the dyestuff is 
as low as possible. The particle sizes of the dyestuffs are in general 
between 0.5 and 5 .mu.m, preferably about 1 .mu.m. 
The dispersing agents also to be employed in the grinding operation can be 
nonionogenic or anionic. Nonionogenic dispersing agents are, for example, 
reaction products of alkylene oxides, such as, for example, ethylene oxide 
or propylene oxide, with compounds which can be alkylated, such as, for 
example, fatty alcohols, fatty amines, fatty acids, phenols, alkylphenols 
and carboxylic acid amides. Examples of anionic dispersing agents are 
lignin-sulphonates, alkyl- or alkylaryl sulphonates or 
alkyl-arylpolyglycol-ether sulphates. 
The dyestuff formulations thus obtained should be pourable for most methods 
of use. The dyestuff and dispersing agent content is therefore limited in 
these cases. The dispersions are in general brought to a dyestuff content 
of up to 50% by weight and a dispersing agent content of up to about 25%. 
For economic reasons, the dyestuff contents usually do not fall below 15% 
by weight. 
The dispersions can also additionally contain other auxiliaries, for 
example those which act as oxidizing agents, such as, for example, sodium 
m-nitrobenzene sulphonate, or fungicidal agents, such as, for example 
sodium o-phenyl-phenolate and sodium pentachlorophenolate, and in 
particular so-called "acid donors", such as, for example, butyrol acetone, 
monochloroacetamide, sodium chloroacetate, sodium dichloroacetate, the Na 
salt of 3-chloropropionic acid, half-esters of sulphuric acid, such as, 
for example, lauryl sulphate, and sulphuric acid esters of oxyethylated 
and oxypropylated alcohols, such as, for example, butyl glycol sulphate. 
The dyestuff dispersions thus obtained can very advantageously be used for 
preparing printing pastes and dye liquors. They offer particular 
advantages, for example, in the case of continuous processes in which the 
dyestuff concentration of the dye liquors must be kept constant by 
continuously feeding dyestuff into the running apparatus. 
For certain fields of use, powder formulations are preferred. These powders 
contain the dyestuff or the dyestuff mixture, dispersing agents and other 
auxiliaries, such as, for example, wetting agents, oxidizing agents, 
preservatives and dust removal agents, and the abovementioned "acid 
donors". 
A preferred preparation process for pulverulent dyestuff formulations 
comprises removing the liquid from the liquid dyestuff dispersions 
described above, for example by vacuum drying, freeze drying or drying on 
roller dryers, but preferably by spray drying. 
To prepare the dye liquors, the required amounts of the dyestuff 
formulations, which have been prepared in accordance with the above 
instructions, are diluted with the dyeing medium, preferably with water, 
to the extent that a liquor ratio of 1:5 to 1:50 results for the dyeing. 
Other dyeing auxiliaries, such as dispersing, wetting and fixing 
auxiliaries, are in general additionally added to the liquors. A pH of 4 
to 5, preferably of 4.5, is established by addition of organic and 
inorganic acids, such as acetic acid, succinic acid, boric acid or 
phosphoric acid. 
If the dyestuff or dyestuff mixture is to be used for textile printing, the 
required amounts of the dyestuff formulations are kneaded to printing 
pastes in a manner which is known per se, together with thickeners, such 
as, for example, alkali metal alginates or the like, and if appropriate 
other additives, such as, for example, fixing accelerators, wetting agents 
and oxidizing agents. 
The invention is illustrated in more detail by the following examples. 
Percentage data are percentages by weight.