Improvements in Dyeing and Printing Textile Fibres with Aniline and its Homologues or Derivatives.
Year: 1891

page_text: PROVISIONAL SPECIFICATION.
Improvements in Dyeing and Printing Textile Fibres with Aniline
and its Homologues or Derivatives.
I WILLIAM JULES SAMUEL GRAWITZ, of 62 Boulevard Gambetta, Nogent-sur-
Marne (Seine) France, Civil Engineer do hereby declare the nature of this invention
to be as follows:-
:-
When aniline becomes transformed into aniline black by the various processes of
development by weathering after drying the color does not become discharged by
friction but the fibre is weakened. In fact the acid of the aniline salt becomes
partly set free by the very fact of the transformation of the aniline (a mono-acid
amine) into a more condensed body, (aniline black) which is a mono-acid triamine of
tetramine.
I avoid all weakening of the fibre by adding to the mixture suitable for yielding
black, acetates, tartrates, or oxalates of the alkalies or alkali earths which absorb
the acid liberated from the aniline salt. In order that the reaction shall continue
to be produced it is always necessary that there should be present at most one
equivalent of these alkali or alkaline earth salts, for one equivalent of salt of
aniline. Up to this limit, the higher their proportion the more complete is the
preservation of the fibre.
The following example yields excellent results
Salt of aniline (hydrochlorate)
Chlorate of soda.
Acetate of soda (crystallized)
Vanadate of ammonia
Total volume of the bath
300 grammes.
-
100
"
-
225
"
2
-
The drugs dissolved separately are mixed at the time of use.
to add to the bath a few grammes of tartaric acid.
99
3 litres.
It is advantageous
The cotton impregnated with this mixture is dried at a low temperature and
weathered at a temperature not exceeding 30° C. which is sufficient to develop the
black in 24 hours.
I apply this method of preventing the weakening of the fibre, not only to aniline
but to its homologues, toluidines, &c., to primary amines derived therefrom by
substitution, as well as to the various diamines known to be convertible into
coloring matters under the action of the products of decomposition of the chlorates
whatever may be the mixture which determines this decomposition whether
vanadium, copper, or other salts.
By suitably thickening the mixture it may be employed for calico printing and I
claim this application.
Dated this 18th day of August 1891.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Dyeing and Printing Textile Fibres with Aniline
and its Homologues or Derivatives.
1, WILLIAM JULES SAMUEL GRAWITZ of 62, Boulevard Gambetta; Nogent-sur-
Marne (Seine) 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 dyeing or printing textile fibres with aniline and its
homologues or derivatives.
When a mineral salt of aniline becomes converted into aniline black by the
various processes of development by weathering after drying, the fibre is weakened
by the mineral acid of the aniline salt becoming partly set free by the transformation
of the aniline which is a mono-acid amine into aniline black which is probably a
mono-acid tri-amine or tetra-amine.
I avoid all weakening of the fibre by adding to the black producing mixture an
acetate or tartrate of an alkali, or alkali earth which will absorb the mineral acid
liberated from the aniline salt.
The proportion of the alkali or alkali earth salt should not exceed one equivalent
thereof for one equivalent of the mineral aniline salt, otherwise the reaction will
be interfered with.
The best proportions of the alkali salt for the preservation of the fibre, seem to
be three-fourths of one equivalent.
The following example yields excellent results.
Crystallized salt of aniline (hydrochlorate) 129 grammes or 1998 grains.
Chlorate of soda
-
Acetate of soda (crystallized)
Vanadate of ammonia
Water
دو
35+
548
"
"
102
1574
"
"
"
1
15
"
"
"
1 litres
"
2 pints.
Thus for one equivalent of salt of aniline, I use three-fourths of an equivalent
of acetate of soda and one-third of an equivalent of chlorate of soda, or such
quantity of another chlorate as will furnish two equivalents of oxygen by its
decomposition by the salt of vanadium. From two to six equivalents of oxygen
may be thus used to obtain different shades of black.
The various ingredients are to be dissolved separately and mixed at the time of
use and it is advantageous to add to the bath a few grammes of tartaric acid. The
cotton impregnated with this mixture is dried and weathered at a low temperature
as well known by calico-printers. For example a temperature not exceeding 30° (.
is sufficient to develop the black in twenty-four hours. The color is then washed or
treated by the various means for rendering the black fast against greening.
My invention includes the employment of this method of preventing the weakening
of the fibre in dyeing with the homologues of aniline, such as toluidines, etc., the
primary amines derived therefrom by substitution, as well as with the various
di-amines known to be convertible into coloring matters under the action of the
products of decomposition of the chlorates whether this decomposition be brought
about by a salt of vanadium, copper, chromium, iron, or other metals known as
acting efficiently on the chlorates.
The invention extends also to calico printing, for which the same mixture when
suitably thickened may be used, and also for marking linen. The oxalates act as
acetates or tartrates, but their employment is difficult on account of the formation
of an insoluble oxalate of aniline which takes place.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is―
In dyeing or printing textile fibres (whether grey, bleached, or previously dyed)
with the mineral salts of aniline or its homologues or derivatives by the action of a
chlorate and exposure to the air, the combination, with the aniline bath or mixture,
of an acetate or tartrate of an alkali or alkali earth to absorb the acid set free from
the mineral aniline salt, as and for the purpose specified.
Dated May 10 1994.
W. J. S. GRAWITZ,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.