Azocoumarinic-type dyes for the disperse dyeing of textile fabrics

There is provided a new azoic dye having the general formula ##STR1## wherein: A is an aromatic radical of the benzene class which has been substituted with at least one group selected from among alkyl, alkoxyl, N-dialkylamine, halogen, cyano and nitro; PA1 X is selected from the group consisting of NH and O; PA1 R.sub.1 is selected from the group consisting of H, CH.sub.3, OCH.sub.3 and Cl; PA1 R.sub.2 is selected from the group consisting of H, CH.sub.3, OCH.sub.3, Cl; PA1 R.sub.3 is selected from the group consisting of CH.sub.3 and C.sub.2 H.sub.5 ; and PA1 R.sub.4 is the same as R.sub.3, such dye being useful in the printing and dyeing of the textiles, particularly hydrophobic synthetic fibers such as polyester fibers.

BACKGROUND OF THE INVENTION 
Prior to the present invention, there were known azoic dyes containing the 
coumarinic ring. Such dyes do not exhibit outstanding dyeing 
characteristics. The present invention is concerned with dyes of 
azoic-type but with a structure substantially different from the known 
azoic dyes and which have superior characteristics thereover as dyeing 
agents. 
OBJECTS OF THE INVENTION 
An object of this invention is that of providing a new class of dyes that 
will display excellent overall stability characteristics. 
Another object is that of further providing a new class of intermediate 
compounds for obtaining such dyes which intermediates can be referred to 
as paraphenylazo-cyanaceticanilide or 4-cyanaceticamido-azophenyl 
compounds, hereinafter "cyanacetic-anilide" for brevity's sake. 
These and still other objects, which will appear even more clearly to the 
skilled in the art, are achieved according to this invention. 
SUMMARY OF THE INVENTION 
The present invention comprises a new class of azoic dyes falling under the 
formula: 
##STR2## 
wherein: A is selected from the group consisting of a residue of a 
diazotizable base also substituted with alkyls, alkoxyls, halogens, 
sulphomethyl groups, sulphamide groups, cyano-groups, nitro-groups, 
acetamide groups and a residue of a coupling base substituted with 
N-dialkylamine groups and also with a group selected from the group 
consisting of alkyl, alkoxyl and acetamide groups. 
X is selected from the group consisting of NH and O; 
R.sub.1 is selected from the group consisting of H, CH.sub.3, OCH.sub.3 and 
Cl; 
R.sub.2 is selected from the group consisting of H, CH.sub.3, OCH.sub.3, 
Cl; 
R.sub.3 is selected from the group consisting of CH.sub.3 and C.sub.2 
H.sub.5 ; 
R.sub.4 is the same as R.sub.3. 
The new azoic dyes, corresponding to formula (I), allow one to obtain 
dyeings and printings of a shade ranging from yellow to orange, on 
hydrophobic synthetic fibres, more particularly on polyester fibres, with 
a high dyeing strength and good overall characteristics, in particular 
fastness to light, fastness to wet and thermal treatments. 
The present invention also provides a new class of intermediate compounds 
for obtaining the novel dyes mentioned above, such intermediate compounds 
being referred to as paraphenylazocyanaceticanilide or 
4-cyanaceticamidoazophenyl compounds of "cyanaceticanilide" for brevity's 
sake. 
GENERAL DESCRIPTION OF THE INVENTION 
As indicated earlier, the present invention concerns a new class of azoic 
dyes having the general formula: 
##STR3## 
wherein: A is selected from the group consisting of a residue of a 
diazotizable base also substituted with alkyl, alkoxyls, halogens, 
sulphomethyl groups, sulphamidic groups, cyano-groups, nitro-groups, 
acetamide groups and a residue of a coupling base substituted with 
N-dialkylamine groups and also with a group selected from the group 
consisting of alkyl, alkoxyl and acetamide groups. 
X is selected from the group consisting of NH and O; 
R.sub.1 is selected from the group consisting of H, CH.sub.3, OCH.sub.3 and 
Cl; 
R.sub.2 is selected from the group consisting of H, CH.sub.3, OCH.sub.3 and 
Cl; 
R.sub.3 is selected from the group consisting of CH.sub.3 and C.sub.2 
H.sub.5 ; 
R.sub.4 is the same as R.sub.3. 
These dyes are suitable for applications of the "thermosol" type 
(190.degree. - 220.degree. C). 
The dyes of this invention have, moreover, shown an excellent behavior in 
the dyeing and printing of mixed polyestercotton fibres, according to 
known processes in use at present. 
For this latter application, the dyes must satisfy particular requisites 
such as: 
a satisfactory affinity for polyester fibres; 
an affinity for cotton in the presence of swelling agents; 
possibility of obtaining dyes with very limited differences in shades on 
the two fibres. 
The dyes of formula (I) are obtained by reacting products of structure (II) 
cyanaceticanilide with a p-N-dialkylaminosalicylaldehyde (III) according 
to the scheme: 
##STR4## 
wherein: A, R.sub.1, R.sub.2, R.sub.3, R.sub.4 have the meaning already 
indicated. 
In practice, the intermediate (II) cyanaceticanilide is dissolved in an 
organic solvent, preferably dimethylformamide and/or ethanol. This 
solution is then treated with p-N-dialkylaminosalicyl aldehyde in the 
presence of a basic catalyst and is then reflux-heated for about 1 hour. 
There is formed a precipitate which is filtered, washed and dried. Thereby 
is obtained a compound within the above formula I wherein X = NH. 
By treating compound with X = NH with diluted HCl there is obtained 
compound wherein X = O. 
As the basic catalyst, piperidine is preferably used. 
Intermediate (II) which participates in the reaction (1) is obtained by 
condensation according to known methods between the aminoazo compound (IV) 
and the compound (V) (acid or cyanacetic ester), according to the 
reaction: 
##STR5## 
wherein: A, R.sub.1, R.sub.2 have the meaning already indicated; 
Y = oh, or (with R = low alkyl). 
The amino-azo compound (IV) can, in its turn, be obtained by conventional 
methods: 
(a) by diazotizing an A base (e.g.: aniline, toluidine, anisidine, 
xylidine, chloro-aniline, 2-nitro-4-methoxyaniline) and by coupling it 
with the amine of formula: 
##STR6## 
(b) by diazotizing and coupling 4-nitro-aniline of formula: 
##STR7## 
with a coupling base A (e.g.: N-dimethyl-aniline, 
N-dimethyl-chloroaniline, N-dimethyl-m-toluidine) and by the subsequent 
reduction of the nitro-group. 
Reaction (2) of the amino-azo compound (IV) with compound (V) is conducted 
according to conventional procedures, e.g., by direct condensation of 
compound IV with cyanacetic ester or by condensation of compound IV with 
cyanacetic acid, in this latter case also in the presence of PCl.sub.5. 
SPECIFIC DESCRIPTION OF THE INVENTION 
The following examples illustrate the inventive idea without, however, 
limiting its scope.

EXAMPLE 1 
##STR8## 
22.5 g of aminoazotoluene were dissolved in 100 ml of dimethylformamide, 
and to this solution were added 71.5 g of ethyl cyanacetate. This mixture 
was then reflux-heated for 3 hours. 
After cooling down and acidification with HCl, the mixture was diluted with 
water and the precipitated cyanaceticanilide [intermediate (II)] was 
filtered. The unreacted amine remained in solution as hydrochloride. The 
precipitate was then washed with water until attaining neutrality and, 
after drying, 17.52 g of cyanaceticanilide were obtained. This same 
cyanaceticanilide was also obtained with lower outputs by adding, in small 
portions, 48 g of PCl.sub.5 to a suspension of 45 g of amino-azotoluene 
and 21 g of cyanacetic acid in 400 ml of toluene, under stirring and at 
room temperature. 
After heating for 3 hours at 100.degree. C the suspension was cooled down 
and the suspended solid was filtered. 
This latter was then treated with dimethylformamide, acidified with HCl and 
then poured into water. After filtering, washing and drying, there were 
obtained 10 g of the cyanaceticanilide corresponding to general formula 
(II). 
29.2 g of such cyanaceticanilide were then dissolved in 200 ml of 
dimethylformamide and 400 ml of ethanol. To this solution were added 21.23 
g of N-diethyl-salicyl aldehyde and 1.38 g of piperidine and the whole was 
then reflux-heated for one hour. Thereby formed a precipitate which was 
filtered and washed with ethanol first and then with water. After drying 
there were obtained 40.5 g of the yellow azoic iminocoumarin dye that 
showed the following percentage analysis: 
Found percentage : C = 71.99-72.22; H = 6.22-6.26; N = 15.12-15.18; 
Theoretical percentage for C.sub.28 H.sub.29 N.sub.5 O.sub.2 : C = 71.9; H 
= 6.2; N = 15. 
The product showed a maximum absorption in the visible spectrum at .lambda. 
460 m.mu.(acetone) and in the IR spectrum (nujol) clearly revealed the 
presence of an intense band in the 6.mu. zone, attributable to the C.dbd.O 
group, and an absorption typical of iminic NH in the 3.mu. zone. 
EXAMPLE 2 (dyeing): 
In an apparatus for pressurized dyeing, 100 g of a preventively scoured 
polyester fabric were treated for 10-15 minutes in a 2-liter dyeing bath 
at 50.degree. C containing: 
2 g/lt of ammonium sulphate, 
1 g/lt of ELU emulsion (non-ionogenic surfactant, produced by Montedison). 
To this dyeing bath was then added 1 g of the dye prepared according to 
Example 1, previously dispersed and filtered through a sieve. The bath was 
then brought to a pH = 5.5 with formic acid, heated over between 20-30 
minutes up to 90.degree. C, thereafter slowly raising the temperature to 
attain 130.degree. C at which level it was maintained for 60 minutes. 
At the end of the dyeing, the bath was cooled down to 80.degree.-85.degree. 
C, then it was discharged, the fabric was rinsed and then submitted to a 
reducing alkaline treatment for 20 minutes at 80.degree. C with a bath 
containing: 
2 ml/lt of caustic soda at 36 Be 
2 g/lt of Albite A (Na.sub.2 S.sub.2 O.sub.4 at 85%) 
0.5 g/lt of Diapal CW (non-ionogenic detersive, produced by Montedison). 
The fabric was then abundantly rinsed and dried. The dyeing thus obtained, 
of a bright yellow tone, displayed a high intensity, good light and 
moisture fastnesses, and an excellent stability under thermal treatments. 
EXAMPLE 3 (dyeing) 
The polyester-cotton fabric, suitably scoured, was printed with a paste of 
the following formulation: 
______________________________________ 
dye (Example 1) 8 g 
alginate thickener 50 g 
diethylenglycol diacetate 
8 g 
water 34 g 
______________________________________ 
The dried fabric, by retaining some solvent useful for the fixing of the 
dye, was thermo-fixed in hot air at 200.degree. C for 1 - 2 minutes. Then, 
it was first washed in running water, then subjected to hot soaping and 
finally rinsed in running water, thereby obtaining a printing of a yellow 
tinge, free of contrast, with high characteristics of light fastness, 
resistance to moisture, to rubbing and stable to thermal treatments. 
EXAMPLE 4 
##STR9## 
23.35g of the azo-iminocoumarin dye, obtained according to Example 1, were 
reflux-treated for about 15 hours with 1000 ml of 5% HCl and a few drops 
of sodium sulphoricinate. 
The solid was filtered, washed in water and, after drying, there were 
obtained 21.8 g of a yellow azocoumarinic dye showing the following 
percentage analysis: 
Found percentage: C 72.12-72-21, H = 6.20-6.15, N = 12.06-11.97; 
Theoretical percentage for C.sub.28 H.sub.28 N.sub.4 O.sub.3 : C = 71.8%, 
H = 6%; N = 11.9%. 
The product showed a maximum absorption in the visible spectrum at .lambda. 
440 m.mu. (acetone) and clearly showed in the IR spectrum (nujol) the 
presence of an intense band in the 6.1.mu. zone typical of the C.dbd.O 
group. 
Moreover, there was observed the disappearance of the absorption of the 
iminic NH group in the 3.mu.-zone. 
By applying this dye onto polyester, according to Example 2, there was 
obtained a dyeing of a bright yellow tinge, with high intensity, a good 
light fastness, resistance to moisture and an excellent stability under 
thermal treatments. 
By applying this dye onto polyester-cotton fabrics, according to Example 3, 
there was obtained a yellow tinged print without contrasts, having high 
light-fastness characteristics, resistance to moisture and rubbing, and 
stability to thermal treatments. 
EXAMPLE 5 
##STR10## 
The aminoazo-p-(N-dimethylamino)-benzene, which is reacted with the ethyl 
cyanacetate, was obtained by diazotizing the p-nitroaniline, by coupling 
on N-dimethylaniline and finally by reduction of the NO.sub.2 group. 
Operating as indicated in Example 1, 4.8 g of aminoazo-p-(N-dimethylamino) 
benzene were reacted with 14.3 g of ethyl cyanacetate thus obtaining 2.4 g 
of cyanaceticanilide which in turn are condensed with 3.2 g of 
N-diethylsalicilic aldehyde, thereby obraining 2.5 g of a yellow 
azoiminocoumarinic dye which at the percentual analysis showed to be in 
good accord with the values calculated for C.sub.28 H.sub.30 N.sub.6 
O.sub.2 and to have a .lambda. absorption in the visible spectrum at 450 
m.mu. (acetone). 
In the IR spectrum there was observed an intense band near to 6.mu., 
typical for the C.dbd.O group, and the presence of the iminic NH group 
around 3.mu.. 
When applying this dye on polyester, according to Example 2, one obtains a 
dyeing of a bright yellow tinge of high intensity, with a good light 
fastness, resistance to moisture, as well as an excellent stability under 
thermal treatments. 
When applying the dye on a polyester-cotton fabric according to Example 3, 
there is obtained a printing in a yellow tone without contrasts, with high 
characteristics of light fastness, resistance to moisture and to rubbing 
and stability under thermal treatments. 
In a way similar to that of the examples described above, there were 
prepared the dyes and obtained the dyeings and printings recorded in the 
following table: 
TABLE 
__________________________________________________________________________ 
Shades obtained on 
poly- 
polyester- 
Ex. 
DYE ester 
cotton 
__________________________________________________________________________ 
6 
##STR11## Yellow 
Yellow 
7 
##STR12## Yellow 
Yellow 
8 
##STR13## Yellow 
Yellow 
9 
##STR14## Yellow 
Yellow 
10 
##STR15## gold yellow 
gold yellow 
11 
##STR16## orange 
orange 
12 
##STR17## orange 
orange 
__________________________________________________________________________ 
Shades obtained on 
Ex. Polyester 
n.degree. 
DYE Polyester 
cotton 
__________________________________________________________________________ 
13 
##STR18## gold yellow 
gold yellow 
14 
##STR19## gold yellow 
gold yellow 
__________________________________________________________________________