Improvements in Dyeing or Printing Fibres Black, or Shades approaching thereto, with Aniline, its Homologues, or Derivatives.
Year: 1895

page_text: Date of Application (in United Kingdom), 6th Feb., 1895
Complete Specification Left, 6th Feb., 1895-Accepted, 20th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in Dyeing or Printing Fibres Black, or Shades
approaching thereto, with Aniline, its Homologues, or
Derivatives.
I, WILLIAM JULES SAMUEL GRAWITZ, of 62, Boulevard Gambetta, Nogent-
sur-Marne, Department du Seine, in the Republic of France, Civil Engineer, 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 an improved process of dyeing or printing textile
fibres a black colour or shades approaching thereto with aniline, its homologues or
derivatives. Fibres which are dyed by means of a salt of aniline or of one of its
homologues or derivative amines under the oxidizing action of a chlorate (the
colour being developed by ageing-that is, exposing to air in ageing rooms or in
ageing machines after dyeing) are liable to fade. The object of the present
invention is to overcome this defect by the employment of a soluble sulfo-cyanate
together with a salt or a compound of vanadium or any other agent capable of
bringing about the decomposition of the chlorate and its reaction on the salt of
aniline employed, such as for instance, perchloride of iron.
It will be understood that two or more soluble sulfo-cyanates may be used
together, and also that sulfo-cyanate of aniline may be used, the sulfo-cyanate of
aniline being easily prepared by mixing a solution of sulfo-cyanate of barium with
a heated solution of sulfate of aniline. Likewise two or more salts of aniline
may be employed together, for instance hydrochlorate of aniline and nitrate of
aniline.
Likewise vanadate of ammonium may be used conjointly with another soluble
vanadate. In the same way chlorate of potassium may be substituted for chlorate
of sodium or for any other soluble chlorate, or several may be used together.
I do not confine myself to the use of pure aniline in the process of dyeing a fast
black, as this process is applicable to its homologues, such as toluidines, xylidines,
or derivatives such as paraphenylendiamine, and in general to all artificial amines,
which are known to yield dark colors by the same process that transforms pure
aniline into black. I use said process both for printing or for dyeing purposes and
whether the fibres to be treated are grey, or bleached, or dyed in the raw state,
spun or woven or in course of manufacture.
I will here indicate, merely by way of two examples, the preparation of the
dve-baths :-

page_text: FIRST EXAMPLE.
-
1295 grammes.
-
570
do.
-
710
do.
Aniline salt (hydrochlorate, or one equivalent)
Soluble sulfo-cyanate of ammonium (crystallized, or of an
equivalent)
-
-
Chlorate of sodium (or 3 of an equivalent) containing
4 equivalents of oxygen
Lave
Soluble sulfo-cyanate of ammonium (crystallized)
Crystallized chloride of manganese
Chlorate of sodium
-
1250 grammes.
570
do.
-
750
do.
-
710
do.
In both examples, the substances are dissolved separately and mixed luke-warm,
enough water being added to make a total volume of 13 litres, and after cooling,
one gramme of vanadate of ammonium dissolved in one hundred grammes of water,
is added to the bath.
The fibrous materials impregnated with this mixture take a magnificent black
by ageing, that is, on being exposed to the air in an ageing room or an ageing
machine.
I would have it understood that the proportion above indicated may be varied.
In conclusion I would remark that in order to obtain a good colour on silk, it is
preferable to repeat the dyeing operation several times.
The wool chlorinated as indicated by Lightfoot, or treated by any other known
process can be dyed a fast black with my process.
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 process herein described of dyeing or printing textile fibres a fast black by
means of a salt or salts of aniline, which consists in impregnating said fibres with a
solution in water of an aniline-salt, a soluble sulfo-cyanate, a chlorate, and one or
more salts of vanadium or any other agent capable of producing the decomposition
of the chlorate, and then subjecting the fibres to an ageing operation, substantially
as set forth.
Dated this Sinth day of Wahmw 1905
JOHN P. O'DONNELL,
70 & 71, Palace Chambers, Westminster, London, S.W.,
Agent for the said Applicant.