THE PRODUCTION OF NEW COLOURING MATTERS SUITABLE FOR DYEING AND CALICO-PRINTING
Year: 1880

page_text: LETTERS PATENT to Otto Nicholas Witt, Ph.D., of Mülhausen (Alsace), in the
Empire of Germany, for an Invention of "THE PRODUCTION OF NEW
COLOURING MATTERS SUITABLE FOR DYEING AND CALICO-PRINTING”
PROVISIONAL SPECIFICATION left by the said Otto Nicholas Witt at the
Office of the Commissioners of Patents on the 22nd November 1880.
OTTO NICHOLAS WITT, Ph.D., of Mülhausen (Alsace), in the Empire of Germany.
"THE PRODUCTION OF NEW COLOURING MATTERS SUITABLE FOR DYEING AND
CALICO-PRINTING."
If the organic bases of the aromatic series known to chemists as metadiamines,
such as metaphenylendiamines or metatoluylenediamines be exposed to the action
of the nitroso derivatives of tertiary aromatic amines such as nitroso-dimethyl-
aniline, or of the nitroso derivatives of phenols, such as, for instance, nitroso-phenol,
a reaction takes place which results in the formation of new colouring matters.
The same colouring matters may be obtained by the action of oxidising agents
upon a mixture of one of the said metadiamines, and the products of reduction of the
above named nitroso compounds, such as, for instance, amidodimethylaniline or
amidophenol. Instead of the latter the amido derivatives of secondary bases (such
as amidodiphenylamine or amidomonomethylaniline) and even primary para-
diamines (such as paraphenylenediamine) may be used.
The colouring matters thus obtained can be used advantageously for dyeing or
calico printing, or they may be transformed into other dye-stuffs, which, on account
of their greater power of resistance to atmospheric influences, are even preferable
to those obtained by the direct process. This transformation takes place spon-
taneously if the acidulated solution of the first-named dye-stuffs be kept for some
time either in closed or in open vessels. It may be accelerated by various means,
such as the injection of a current of air or the addition of oxydising agents; the
reaction is more complete if the liquid be heated for a while either under
atmospheric or increased pressure, with or without an injection of steam or air
with or without the addition of oxydising agents.

page_text: To obtain a violet-colouring matter I dissolve molecular weights of meta-
phenylenediamine and nitrosodimethylaniline-hydrochloride in water. I heat this
mixture by a steam jet adding small quantities of hydrochloric or other acid from
time to time. I keep the liquid boiling until its colour ceases to increase in intensity.
After cooling I precipitate the colouring-matter either by the addition of salt in
the shape of a hydrochloride, or as a double chloride by the addition of a suitable
metallic salt, or in the shape of the free base by adding an alkali. I separate the
precipitate from the mother-liquor by filtration and finish it by drying.
If in the above process the metaphenylenediamine be replaced by metatoluylene-
diamine a red colouring matter may be obtained.
Instead of metaphenylenediamine I may use, as before said, any other
metadiamine or its methylated, athylated, or amylated derivatives instead of
nitrosodimethylaniline, nitrosophenol, or any other nitroso compound may be used.
Instead of any of the said nitroso compounds I may use the substances which have
been described and are known to chemists under the name of chloro-quinonemides,
and which may be easily obtained by treating the hydrochlorides of amidophenols
or paradiamines such as paramidophenolhydrochloride or paraphenylenediamine-
hydrochloride, or any of their homologues or products of substitution with an aqueous
solution of chloride of lime (bleaching powder). The products thus obtained are
easily transformed into colouring matters by the addition of a corresponding
quantity of any of the above named diamines. I prefer however however for the
present the combinations above described, as the ingredients may be easily
obtained in any quantity and at a cheap price.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Otto Nicholas Witt in the Great Seal Patent Office on the
20th May 1881.
OTTO NICHOLAS WITT, Ph.D., of Mülhausen (Alsace), in the Empire of Germany.
"THE PRODUCTION OF NEW COLOURING MATTERS SUITABLE FOR DYEING AND
CALICO-PRINTING."
If the organic bases of the aromatic series known to chemists as metadiamines,
such as metaphenylenediamine or metatoluylenediamine be exposed to the action
of nitrosoderivatives of tertiary aromatic amines such as nitrosodimethylaniline or
its homologues, or of the nitrosoderivatives of phenols, such as, for instance, nitroso-
phenol, or of the substances known as chloroquinoneimides, a reaction takes place
which results in the formation of new colouring-matters. The same colouring-
matters may be obtained by the action of oxydising agents upon a mixture of one
of the said metadiamines and one of the paramidoderivatives of phenols or
secondary or tertiary aromatic bases and even primary paradiamines.
The colouring-matters obtained by either of the above two processes can be
used directly for dyeing and calico-printing, paper staining, or ink-making, or they
may be transformed into other dye-stuffs, which, on account of their greater power
of resistance to atmospheric influences, are preferable to those obtained by the
direct process.
This transformation takes place spontaneously if the neutral or
acidulated solution of the first named dye-stuffs be kept for some time either in a
closed or in an open vessel. It may be accelerated by various means, such as the
injection of a current of air, either hot or cold, or the addition of an oxydising
agent; the reaction is more complete if it takes place at an increased temperature,
and thus the liquid may be kept boiling for a while, or it may be heated under
increased pressure, both with or without an injection of steam or air, with or
without the addition of oxydising agents.
I will now describe, as an instance, the manner in which I have hitherto
proceeded to obtain a violet colouring-matter without however confining myself to
this example, as these colouring-matters are formed in many different ways by the
reaction of the named products upon each other.
I place in a wooden vat 186 lbs of nitrosodimethylaniline hydrochloride, I then
add a solution of 108 lbs of metaphenylenediamine in 216 gallons of water; I take
care to obtain a perfect solution by vigorous stirring, and when this is the case, I
allow the liquid to remain undisturbed during several hours. The liquid contains
now a dark-blue colouring matter of the first class described, which may be
precipitated by salt and collected, but generally I prefer to transform it in a more
stable violet colouring without previous precipitation. For this purpose I introduce
a steam-jet and gradually raise the temperature of the liquid to the boiling point. At
this stage of the operation I introduce gradually 116 lbs. ordinary aqueous
hydrochloric or a corresponding quantity of any other acid. I may, but this is not
absolutely necessary, facilitate the reaction by the injection of cold or hot air, or by
adding an oxydising agent, such as, for instance, ferric chloride. When the colour
of the solution ceases to increase in intensity I allow the liquid to cool, and then
precipitate the colouring-matter which it now contains by the addition of a salt,
such as sodic chloride or acetate, zincic chloride, or even by soda. In the latter
case the precipitate, after filtering and before drying it, must be mixed with so
much hydrochloric acid as is necessary to allow, after drying, of a ready solution in
hot water. The necessary quantity of hydrochloric acid may be easily ascertained
by a previous test. If in the above process I replace the metaphenylenediamine
by 122 lbs. of metatoluylenediamine, I obtain by simple standing a blue colouring

page_text: matter, which, on applying heat as described is readily transformed into a dark
red colouring matter.
Having thus described my process, I wish it to be understood that I do not
confine myself to the above named ingredients, quantities, or conditions. Thus I
may, instead of working in aqueous solutions, allow the reaction to take place by
mere fusion of the ingredients, or I may employ any other suitable solvent; or I
may change the proportions indicated, and thus vary the shades of the dye-stuffs
obtained; instead of metaphenylenediamine, I may use as aforesaid any other
aromatic metadiamine, or its methylated, aethylated, or amylated derivatives;
instead of nitrosodimethylaniline I may use nitrosophenol or any other nitroso
compound, or any of the substances known to chemists under the name of
chloroquinoneimides, and which may be obtained by the action of chloride of lime
(bleaching powder) upon paradiamines or paraamidophenols. The manner of
working with these compounds is exactly the same as described above.
I prefer, however, at present the combinations above described, as the ingredients
may be easily obtained in any quantity and at a moderate cost.
The following is the description of a process for preparing the same colouring
matters by simultaneous oxydation of a metadiamine with one of paramido
derivatives of the phenols, primary, secondary, cr tertiary aromatic bases, such as,
for instance, amidodimethylaniline.
add 100 lbs
of ordinary hydrochloric acid. I then introduce a solution of 108 lbs. of meta-
phenylenediamine (or 122 lbs. of metatoluylenediamine, as the case may be) in
216 gallons of water; I take care to obtain a perfect mixture by vigorous
stirring, and then gradually introduce the solution of some oxydising agent, such
as ferric chloride or potassic ferricyanide. From time to time I convince myself
by a test whether a further addition of oxydising agent still increases the quantity
of dye-stuff formed. If this be not the case, and a very slight excess of oxydising
agent may be shown to be present, the liquid contains a large quantity of a blue
colouring matter, which may be transformed into a violet or red one by the
injection of steam and air exactly as described above.
I place in a wooden vat 136 lbs. of paraamidodimethylaniline, and
Having thus fully described and explained the nature of my Invention, I wish it
to be understood that I claim as the new and essential part of my Invention,―
First. The production of the new colouring matters resulting, as herein described,
from the actions of chloro-quinone-imides or nitroso-derivatives of tertiary
aromatic amines or phenols upon aromatic metadiamines.
Second. The production of the new colouring matters resulting, as herein
described, from the simultaneous oxydation of aromatic metadiamines, and the
paraamidoderivatives of phenols, or primary, secondary, or tertiary amines.
Third. The production of other new colouring matters resulting, as herein
described, from the change by heat and other agents of the new colouring matters:
referred to in the first and secondary claiming clauses.
In witness whereof, I, the said Otto Nicholas Witt, have hereunto set my
hand and seal, this Sixteenth day of May, in the year of our Lord One
· thousand eight hundred and eighty one.
OTTO NICHOLAS WITT. (L.S.)