Process for Production of Black Azo Dyes on the Fibre.
Year: 1894

page_text: Date of Application, 15th June, 1894
Complete Specification Left, 15th Mar., 1895-Accepted, 20th Apr., 1895
[Communicated from abroad by THE FARBWERKE, vormals MEISTER LUCIUS
AND BRUNING, of Hoechst a/ Main, in the Empire of Germany, Chemical
Manufacturers.]
Process for Production of Black Azo Dyes on the Fibre.
I, OLIVER [MRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:—
The production of insoluble azo dyes on the fibre, especially in calico printing,
extends from year to year according to the increased facilities of adding new dyes
to those already obtained, and of thus attaining the desired end, namely the
production of every colour on a grounding of ẞ naphthol.
Up to the present time fine and fast red bordeaux, orange, and recently blue,
tints, also a variety of fashionable colours can be produced on goods prepared with
B naphthol. Of the missing colours the most important is a good black. It has
hitherto been impossible to produce such a colour by the employment of a single
base. By employing various substances only a dark dirty violet or grey has been
obtained even with the greatest possible concentration of the printing colour.
As it was impossible to obtain a practical black by a chemical method alone,
physical means were adopted, that is to say, the use at the same time of two bases
which produce dark colours with 3 naphthol, of a quite different shade, but
complementary to one another.
It was found that for the one shade, dianisidine or diphenctidine which produces
a dark violet, and for the other, meta-nitro-aniline, benzidine or toluidine which
produces yellowish orange and dark brown, were the most suitable substances.
The mixture of two of these colours contains the necessary primary colors for
black namely blue, red and yellow.
The colour obtainable in this way is sufficiently good in shade and sufficiently
fast, greatly excelling logwood black and almost equalling aniline black. The
advantages of a black which can be produced directly on the fibre are self evident.
Formerly, in order to obtain black and red articles which were so popular, it was
necessary to print the black first, to hang up the goods for 24 hours until the colour
was developed, and then to finish according to known methods.
The difficulties were still greater in the case of a simultaneous reserve for white
printed under black.
The reserve preparations are mostly strongly hygroscopic and absorb water by
hanging up with the simultaneously printed aniline black. The result is that
blurred outlines and a bad white are obtained.
The new black, according to this invention, on the contrary, is easily reservable,
like all other azo colours and is printed simultaneously with the diazo-para-nitro-
aniline over the reserve.
The effects thus obtainable are extremely beautiful and the process for producing
them is cheap.
More than the calculated quantity of nitrite can be employed for the diazotation
of the above mentioned bases in order to obtain particular shades. This however
does not attack.the "doctor" and the printing mixtures keep very well.

page_text: COMPLETE SPECIFICATION.
Process for Production of Black Azo Dyes on the Fibre.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
The production of insoluble azo dyes on the fibre, especially in calico printing,
extends from year to year according to the increased facilities of adding new dyes
to those already obtained, and of thus attaining the desired end, namely the
production of every colour on a grounding of ẞ naphthol.
It has
Up to the present time fine and fast red bordeaux, orange, and recently blue
tints, also a variety of fashionable colours can be produced on goods prepared with
ẞ naphthol. Of the missing colours the most important is a good black.
hitherto been impossible to produce such a colour by the employment of a single
base. By employing various substances only a dark dirty violet or grey has been
obtained even with the greatest possible concentration of the printing colour.
As it was impossible to obtain a practical black by a chemical method alone,
physical means were adopted, that is to say, the use at the same time of two bases
which produce dark colours with ẞ-naphthol of a quite different shade, but
complementary to one another.
It was found that for the one shade, dianisidine or diphenetidine which produces
a dark violet, and for the other, meta-nitro-aniline, benzidine or toluidine which
produces yellowish orange and dark brown, were the most suitable substances.
The mixture of two of these colours contains the necessary primary colours for
black namely blue, red and yellow.
The colour obtainable in this way is sufficiently good in shade and sufficiently
fast, greatly excelling logwood black, and almost equalling aniline black, The
advantages of a black which can be produced directly on the fibre are self evident.
Formerly in order to obtain black and red articles which were so popular, it was
necessary to print the black first, to hang up the goods for 24 hours until the
colour was developed, and then to finish according to known methods.
The difficulties were still greater in the case of a simultaneous reserve for white
printed under black.
The reserve preparations are mostly strongly hygroscopic and absorb water by
hanging up with the simultaneously printed aniline black. The result is that
blurred outlines and a bad white are obtained.
The new black according to this invention, on the contrary, is easily reservable,
like all other azo colours and is printed simultaneously with the diazo para-nitro-
aniline over the reserve.
The effects thus obtainable are extremely beautiful and the process for producing
them is cheap.
More than the calculated quantity of nitrite can be employed for the diazotation
of the above mentioned bases in order to obtain particular shades. This however
does not attack the "doctor" and the printing mixtures keep very well.

page_text: 4
280 grammes metanitro-aniline base are dissolved in
600 cubic centimetres hydrochloric acid of 21° Bé: and
2 litres of hot water;
the solution is cooled down by the addition of 2500 grammes of ice or by ice
water, and, while continuously stirring, 500 cubic centimetres of nitrite solution
(290 grammes per litre) are added.
After the diazotation is complete the whole is diluted to 7500 cubic centimetres.
150
,,
"
acetate of soda.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The herein described process for the production on the fibre of black azo
colours of various shades by combining with naphthols on the fibre mixtures of
bases which give dark violet, such as dianisidine or diphenetidine, and of bases
which give yellow orange or brown colours, such as aniline, the toluidines, the
nitro-anilines, benzidine and tolidine, in various proportions.
Dated this 15th dow of Mauh 100%
ABEL & IMRAY,
Agents for Applicant.