Improvements in the Manufacture of Colouring Matters.
Year: 1895

page_text: Date of Application, 10th July, 1895-Accepted, 10th Aug., 1895
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring Matters.
We, JOSEF WELLER of 11A Harzweg, D.Ph., Chemist and WILHELM BRAUNS
of 13 and 14 Harzweg, Manufacturer, both of Quedlinburg am Harz in the
German Empire, 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 :-
This invention relates to the manufacture of induline and the like colouring
matters which are easily soluble in alcohol and the sulpho acids of which are
soluble in an alkali.
At present these colours are produced by melting together aniline, aniline
hydrochloride and mononitrophenol at a temperature of from 210 to 230 degrees
Centigrade. The sulpho acids of the product are not suitable for dyeing cotton
although they are sometimes employed for wool with the result however that the
wool is frequently unevenly dyed owing to the free sulpho acids being precipitated
after the addition of acids.
But we have found that trinitrophenol acts on aniline and aniline hydrochloride
at a temperature of about 120 degrees Centigrade and the produced sulpho acids
have an affinity for cotton and will dye wool evenly in the brightest shades.
The method of carrying this invention into effect for the production of colouring
matters soluble in alcohol is as follows
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200
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parts of aniline hydrochloride,
parts of trinitrophenol,
parts of aniline oil, and
0.5 part of vanadate of ammonia,
are heated and stirred in a cast iron vessel fitted with a condenser and agitator for
about 6 hours at a temperature of about 120 degrees Centigrade. The vanadate
of ammonia is not absolutely necessary and it may be dispensed with but its
presence facilitates the reaction. The substances under treatment at first are red
but by degrees become violet. It is preferred to moderate the heating at the end
of the first hour and when the temperature has reached 115 degrees Centigrade as
the development of ammonia and water becomes so violent that frothing over
When this reaction has diminished the
can not otherwise well be avoided.
condenser is reversed so that the distillate may come over, and the temperature is
increased and continued for six hours at about 120 degrees Centigrade. The
substance becomes thicker and thicker by degrees, with the distillation of aniline
oil and water until it can be drawn in threads. Samples may be taken to ascertain
When the reaction is completed
when the end of the reaction has been reached.
the hot inelted mass is poured into acidulated water and a test is then made to see
whether the water is still acid. The mass is then treated in a centrifugal machine
and the separated water which contains aniline hydrochloride and a little
trinitrophenol is distilled with soda lye and steam to recover the aniline.
The resulting colouring matter is easily soluble in alcohol with a red or violet
colour, is purified by repeated washings, and consists of a black powder which may
be transformed into compounds soluble in water as will be hereinafter described.
Similar colouring matters may be obtained if the aniline is replaced by another
aromatic amine. By melting picric acid with p-phenylendiamine or m-phenylendi-
amine, compounds with hydrochloric acid soluble in water may be produced which
differ very little from the colouring matters produced from aniline oil. The
production of these colouring matters will also be described hereinafter.

page_text: To transform the colouring matter which is soluble in alcohol into a sulpho
colouring matter soluble in alkaline water it is first dried and powdered and then
placed in four times the quantity of fuming sulphuric acid where it is allowed to
stand at a moderate temperature for from ten to twelve hours. After its complete
solubility has been ascertained by dropping a small sample into ammoniacal water,
it is pured into ice water and vigorously stirred. It is then neutralised with
slaked lime and the easily soluble lime salt of the colour acid is filtered from the
produced sulphate of lime.
The same result may be attained by the addition to the colouring matter of a salt
of sodium such as the carbonate of soda. The lime salt however being equally as
soluble may be advantageously employed.
These colouring matters dye cotton wool and silk from grey to black in a bath
acidified by acetic acid.
If the substance be heated up to a temperature of 140 degrees Centigrade a
bluer colouring matter is obtained, and if further heated to 190 degrees Centigrade
still bluer and darker colouring matters are produced.
To transform the colouring matters soluble in alcohol into combinations with
hydrochloric acid which are soluble in water, we add 100 parts of p-phenylendiamine
and 5 parts benzoic acid to 120 parts of the alcohol soluble colouring matter.
They are melted together and heated to from 130 degrees to 140 degrees Centigrade,
which temperature is maintained for some time. The mass becomes fluid ;
becomes more and more blue, the reaction being stopped when the desired colour
is reached, and being finished when ammonia ceases to be evolved. The hot
melted substance is then poured into dilute hydrochloric acid.
The produced
colouring matter is in solution and may be separated by the addition of sodium
chloride and is then filtered dried and ground. It dyes cotton wool and silk blue-
red to blue in a bath acidified by acetic acid.
In the Specification of the German Patent No. 44406 it is stated that by the
action of nitrobenzol on a mixture of hydrochloric p-phenylendiamine and
phenylendiamine with the addition of a suitable oxygen carrier, colouring matters
are produced which dye cotton previously treated with tannic acid, a greenish blue.
The temperature required is said to be 190 degrees Centigrade.
The nitro-phenols behave quite differently, the trinitrophenol in particular
possessing great powers of reaction. The condensation is accomplished at
a temperature of about 120 degrees Centigrade and is finished in about four hours.
The produced colouring matter is distinguished by its strong affinity for cotton
which it dyes directly. To produce this colouring matter,
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parts of p-phenylendiamine hydrochloride
parts of trinitrophenol
parts of phenylendiamine, and
0-2 part of vanadate of ammonia,
are melted in a cast iron tank at a temperature of 120 degrees Centigrade. The
reaction is finished in four hours the end being marked by ammonia ceasing to be
evolved. The melted substance is then poured into water, dissolved by hydro-
chloric acid and the colouring matter is separated by the addition of sodium
chloride, filtered and dried. The p-phenylendiamine can be replaced by 100 parts
of aniline or by an equivalent weight of m-phenylendiamine. Or the
p-phenylendiamine hydrochloride may be replaced by m-phenylendiamine hydro-
chloride. The quantities and temperature set forth may if desired be varied
within comparatively wide limits.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what we
claim is :-
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page_text: soluble in alcohol and in water, by the action of trinitrophenol upon an aromatic
mono- or di amine hydrochloride alone or dissolved in the free bases with or
without oxygen carriers substantially as herein before described.
2. The hereinbefore described process for the conversion of the alcohol soluble
colouring matter into colour compounds soluble in water, by the action of fuming
sulphuric acid and conversion into lime or soda salts substantially as hereinbefore
described.
3. The hereinbefore described process for the conversion of the alcobol soluble
colouring matter into a colour compound soluble in water by melting it with para-
or meta- phenylendiamine and converting the product into hydrochloride compounds
substantially as herein before described.
Dated this 9th day of July A.D. 1895.
W. E. HEYS & SON,
Agents for the Applicants.
W. E. HEYS & SON,
Agents for the Applicants.