IMPROVEMENTS IN COLOURING MATTER
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of, the
Commissioners of Patents on the 17th July 1883.. A communication from
Heinrich Baum, chemist, a person resident at Höchst on the Main, Germany.
FRANK WIRTH of the firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany IMPROVEMENTS IN COLOURING
MATTER [a communication from Heinrich Baum, chemist, a person resident at
Höchst on the Main, Germany.]
This Invention relates to the preparation of a betanaphtholdisulphoacid from
betanaphthol monosulphoacid and also to the method of preparing the azo colors
from this disulphoacid.
The object of the Invention is the cheap preparation of the azo coloring matters.
The preparation of the disulphoacid is carried out in the following manner :-
Equal weights of the well dried Potash salt (first prepared by Schäffer and
described as very insoluble-Annals 152 page 279 and Berlin Berichte 1869
page 90) of the betanaphthol monosulphoacid and pyrosulphate of potash, are
intimately mixed. The mixture of both substances is then transferred into a
quantity of hydrated sulphuric acid, heated to 120° to 130° C, equal to from 0.8 to
the same weight of the sulphoacid used, the mixture being stirred during the
operation. When everything has dissolved, the mixture is kept at a temperature
of 150°-160° C for five or six hours and then allowed to cool. By this means is
obtained almost exclusively a betanaphtholdisulphoacid which yields a single red
azo coloring matter, and it can be at once used for the preparation of azo coloring
matters without further purification or separation.
An example will show the mode of proceeding.-26 kilogrammes of the well
dried potash salt of the difficultly soluble betanaphthol monosulphoacid is intimately
mixed with 26 kilogrammes of pyrosulphate of potash and this mixture transferred
into its own weight of hydrated sulphuric acid which has been heated to
120°-130° C, stirring being carried on during the operation. The mixture is
then kept for five or six hours at a temperature of 160° C and the melted mass so
obtained is transferred into 3 to 5 times its own weight of water. The solution
is first neutralized with calcium carbonate or lime, and the calcium sulphate which
is formed, separated by filtration. To the solution of the disulphoacid 5 kilo-
grammes of lime in the form of milk of lime are added, and the solution kept at

page_text: a low temperature, by means of ice. 144 kilogrammes of diazobenzolchloride
(obtained by well known methods) are now added to the solution made alkaline
by means of lime, stirring being continued during the operation. The coloring
matter is at once formed and can be obtained pure by redissolving and precipitating
by means of common salt. It forms a fiery yellow-red powder and dies-wool, silk,
and cotton a very yellow tinted Ponceau red. In this description the potasium
salt of the monosulpho acid can, with advantage, be replaced by its sodium or its
ammonium salt. Likewise the corresponding amount of pyrosulphate of potash
can be used in the place of the potassium pyro-sulphate without spoiling the
results. By substituting other diazo compounds for the diazo-benzol chloride, a
series of coloring matters of different shades are obtained.
I claim therefore in the manner described above the following combination.
By substituting in the place of diazo-benzolchloride
1. Diazotoluol
Diazoxylol.
2.
3.
Diazocymol.
4.
Diazoethylxylol.
5. Diazodiphenyl.
6.
Orthodiazoanisol
7.
Diazoparacresolmethylether
yellow ponceau.
ponceau.
ponceau with blue tint
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8. Diazonaphthalin
9.
Diazonaphthalin
10. Diazonaphtholmethylether
11. Orthodiazoanisolsulpho acid;
12 Diazodiphenylsulpho acid
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yellow carmoisin
do with blue tint.
blue tinted ponceau.
ponceau-red.
violet
blue tinted ponceau.
در
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