Matters, and in the Method of Fixing the same.
Year: 1886

page_text: Matters, and in the Method of Fixing the same.
I JOHN CLARK JEFFERSON of 2 East Parade Leeds in the County of York
Engineer and Patent Agent, do hereby declare the nature of said invention for
IMPROVEMENTS IN THE MANUFACTURE OF BLUE DYE STUFFS OR COLORING
MATTERS AND IN THE METHOD OF FIXING THE SAME, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement --
Our Invention is founded on the observation, that when the salts of certain
amidoazo compounds as well as the sulpho acids of the same are melted either with
Benzoldiamine, Toluoldiamine, or Xyloldiamine, they have the property of forming
blue dye stuffs, which are soluble in water.
.
These dye stuffs, when used on cotton which has been mordanted with Tannin,
produce blue colours, which on suitable treatment with oxidizing agents, (such as
bichromate of potash), become darker, and fast both to light and washing. The
best results are obtained by the action of Para-diamidobenzol on Amidoazobenzol,
Amidoazotoluol or on Dimethylamidoazobenzol, which bodies are preferable also on
account of the greater readiness with which they can be produced. Metadiamido-
benzol produces less fixed dye stuffs; the homologues, for example Diamidotoluol,
produce similar dye stuffs but of redder shades. Of the sulpho-acids of the Amido-
azo compounds, only those can be employed in which the sulpho group remains in
the so-called Anil-rest (see Berichte der deutschen chemischen Gesellschaft Jahrgang
1886 p 1542) of the Azo-compounds, and whose chemical composition is represented
by the formula HSO,-C. H.. N.. C. H. NH, moreover it is then quite immaterial
whether an Anil- Tolyl- or Naphtyl rest is combined with that portion of the
Amido-azo compound containing the Amido group. Thus in place of the com
pound Na SO.-C. H.. N. C. H. NH, one may use equally well the compound
Na SO, CH. N. C. H. NH, or Na SO,. C10 H. N. C. H. NH. C. H. As
regards the shades of the dye stuffs to be obtained, besides the diamido derivatives
of Benzol, Toluol, or Xylol, the nature of that portion of the Amido azo compound
containing the Amido group alone is of importance; so that whilst one can use
An idobenzolazotoluol equally as well as Amidoazobenzol, yet it is not immaterial

page_text: whether Amidoazobenzol or Amidotoluolazobenzol is employed: The mode of pro-
ducing the dye-stuffs is the same for all Amido-azo compounds as well as for
Diamidobenzol, Diamidotoluol or Diamidoxylol, and can be explained or illustrated
by a single example, for which we choose the method of preparing the blue dye-
stuff from chlorhydrate of Amidoazobenzol and Paradiamidobenzol
We must. here preface that it is not necessary to follow out the exact proportions
and details of the method here given, the description merely giving the method by
which we have obtained exceptionally good results.
100 Kilogrammes of Paradiamidobenzol are melted in a melting pot or pan
having a distillation apparatus, and to the warm (about 150° C) mass 100 Kilo-
grammes of Chlorbydrate of Amidoazobenzol are added, the mass at the same time
being actively stirred.
:
A strong frothing or effervescence is hereby produced, ammonia and analine vapour
escaping, so that active stirring is required to prevent the melted mass overflowing.
During the reaction the temperature rises to 180° C, which is retained by heating.
The effervescence gradually ceases, the previously thin and fluid mass becomes stiff,
and must then (after taking off the cover of the pan) be stirred about with an
iron rod.
k
In order to be able to determine the end of the process, tests are made at
intervals. A sample is dissolved in hot water with the addition of a little hydro-
chloric acid, filtered, and common salt added to produce precipitation. A small
sample of cotton mordanted with tannin is dyed with the precipitate (dye-stuff)
'thus obtained. As soon as a dyed sample is obtained having the desired shade,
the process is interrupted by removing the fire from under the melting pan. On
cooling the stiffened mass is taken out of the pan, ground, and stirred up with
hot water. A quantity of hydrochloric acid just sufficient for solution is then
added. The solution is filtered warm, and the blue dye-stuff precipitated by means
of common salt, is pressed, dried, and ground, to bring it into the usual marketable
condition.
If free amido-azo-benzol is employed about 5 per cent of Benzoic Acid must be
added. A similar addition is advisable in the employment of the sulpho-acids of
Amido-azobenzol or its Homologues. Very good results are obtained when instead
of Amidoazobenzol, dimethylamidoazobenzol or the sulpho-acids. of phenylamidoazo-
benzol known in the market under the names Tropaeolin OO and Metanil-yellow
are melted with paradiamidobenzol. All the dye-stuffs of this group dissolve
readily in water, and dye vegetable fibres previously mordanted with tannin' to a
strong blue colour.
t
METHOD OF OXIDIZING THE COLOURS PRODUCED BY MEANS OF THE ABOVE
DESCRIBED DYE-STUFFS ON VEGETABLE FIBRES,
If an oxidizing agent, for example bi-chromate of potash is added to an hot-
water solution of one of the above mentioned dye-stuffs, a black precipitate is
produced which is insoluble in water.
We take advantage of this valuable property of our new dye stuffs for "shading"
and "fixing" the colours produced (as now known) on cotton.
We draw the goods, dyed with the above dyestuffs through a boiling bath
containing bi-chromate of potash to the extent of about 5 per cent of the weight
of the dyed stuff, wash well, and treat in the usual manner.
Instead of bi-chromate of potash; chlorate of potash, ferricyanide (red prussiate)
of potash, ferric chloride or similar agents may be employed.
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 :-
1° The mode or modes of producing blue dye stuffs (soluble in water) by the action
of Benzoldiamine, Toluoldiamine, and Xyloldiamine on Amidoazo-compounds, the

page_text: salts of the same, and those sulpho-acids contained in the sulpho-group in the so-
called Anilrest at a temperature between 170° and 190° Centigrade, substantially
according to the above described method.
2° The mode or modes of oxidizing otherwise called "Fixing" and "Shading,"
the colours obtained on cotton with the above mentioned dyestuffs by means of the
usual oxidizing agents, particularly bichromate of potash, chlorate of potash,
prussiate of potash, ferric salts and the like, substantially according to the above
described method.