IMPROVEMENTS IN THE PREPARATION OF THE ALKALI SALTS OF SULPHONIC ACIDS
Year: 1880

page_text: "
LETTERS PATENT to Joseph Anthony Dixon, of 175, West George Street,
Glasgow, in the County of Lanark, North Britain, Solicitor, for an Invention
of IMPROVEMENTS IN THE PREPARATION OF THE ALKALI SALTS OF
SULPHONIC ACIDS." A communication from abroad by Doctor Carl Koenig,
of Höchst-am-Main, in the Empire of Germany, a Director of the Farbwerke
vorm. Meister, Lucius, and Bruning, a Company carrying on business as
Chemical Manufacturers.
PROVISIONAL SPECIFICATION left by the said Joseph Anthony Dixon
at the Office of the Commissioners of Patents on the 11th December 1880.
JOSEPH ANTHONY DIXON, of 175, West George Street, Glasgow, in the County
of Lanark, North Britain, Solicitor. "IMPROVEMENTS IN THE PREPARATION OF
THE ALKALI SALTS OF SULPHONIC ACIDS." [A communication from abroad by
Doctor Carl Koenig, of Höchst-am-Main, in the Empire of Germany, a Director
of the Farbwerke vorm. Meister, Lucius, and Bruning, a Company carrying
on business as Chemical Manufacturers.]
For the production of sulphonic acids it has hitherto always been the rule in
cases where the action of monohydrated sulphuric acid (otherwise called sulphuric
acid monohydrate), or of the common English sulphuric acid, was not sufficient to
use a mixture of these with the so called fuming sulphuric acid.
The present Invention is based on the observation that the sulphonic acid salts
of the alkalis are formed direct when pyrosulphate of soda or of potash, preferably
dissolved in monohydrated sulphuric acid, acts at a high temperature upon the
compound to be sulphonated. In this way the process goes on better and smoother
than in the ordinary way, and the destructive collateral reactions which occasion
loss of material are less operative or effective than when fuming sulphuric acid
is used.
The monohydrated sulphuric acid used according to this new method serves in
those cases in which it does not act of itself as sulphonating agent only as a
solvent for the pyrosulphate and for the substance to be sulphonated. No develop-
ment or liberation of sulphuric anhydride can be perceived during the action of the

page_text: 10 parts of rosaniline dried at 110° centigrade are dissolved in 35 parts of
sulphuric acid monohydrate at 100° centigrade, and then 30 parts of pyrosulphate
of soda in fine powder are added in portions. The mixture is frequently stirred
while being heated, and the heating is kept up for about 1 hours at 120° to
125° centigrade, until a sample gives a clear solution of a yellowish colour in
alkaline water, and this solution, after an addition of largely diluted sulphuric
acid, remains permanently pure red.
The further treatment of the above product of sulphonization for separating the
sulphate of lime and so forth is the same as stated before. However, before the
final evaporation of the soda salt, the properly proportioned quantity of dilute
sulphuric acid is added in order to transform the neutral salt into an acid salt.
3. The Soda Salts of the Mono- and Bisulphonic Acids of Amidoazobenzol
and its Homologues.
10 parts of well dried amidoazobenzol are added to 30 parts of sulphuric acid
monohydrate, and the mixture is heated on the water bath until solution takes
place. Afterwards I add 12 parts of well powdered pyrosulphate of soda in
4 portions, and I digest the whole on the water bath at about 98° centigrade with
constant stirring,

page_text: According to the duration of the reaction I obtain the soda salt of the disulphonic
acid, which is soluble in water, or the soda salt of the mono sulphonic acid, which
is with difficulty soluble in water.
To obtain the former I digest the mixture (containing as above mentioned
twelve parts of pyrosulphate) for about 2 hours, until a sample gives a clear
solution in water, whereas to produce the latter I use only half of the above named
quantity of pyrosulphate, and I digest at 100° centigrade, until a sample gives a
clear solution in ammonia only.
The further treatment of the product is the same as described with regard to the
soda salts of the anthraquinonesulphonic acids.
All that has been said with regard to the formation and the production of the
sulphonic salts of soda applies also to the sulphonic salts of potash.
The proportion and also the degrees of temperature herein before prescribed may
be varied within certain limits.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Anthony Dixon in the Great Seal Patent Office on
the 7th June 1881.
JOSEPH ANTHONY DIXON, of 175, West George Street, Glasgow, in the County
of Lanark, North Britain, Solicitor. "IMPROVEMENTS IN THE PREPARATION OF
THE ALKALI SALTS OF SULPHONIC ACIDS." A communication from abroad by
Doctor Carl Koenig, of Höchst-am-Main, in the Empire of Germany, a Director
of the Farbwerke. vorm. Meister, Lucius, and Brüning, a Company carrying
on business as Chemical Manufacturers.
For the production of sulphonic acids it has hitherto always been the rule in
cases where the action of monohydrated sulphuric acid, otherwise called sulphuric
acid monohydrate, or of the common English sulphuric acid was not sufficient to
use a mixture of these with the so called fuming sulphuric acid.
The present Invention is based on the observation that when pyrosulphate of
soda or of potash, preferably dissolved in monohydrated sulphuric acid, acts at a
high temperature upon the compound to be sulphonated, the sulphonic acid salts
of the corresponding alkalis are formed direct. In this way the process goes on
better and smoother than in the ordinary way, and the destructive collateral
reactions which occasion loss of material are less operative or effective than when
fuming sulphuric acid is used.
The monohydrated sulphuric acid used according to this new method serves in
those cases in which it does not act of itself as sulphonating agent only as a
solvent for the pyrosulphate and for the substance to be sulphonated. No
development or liberation of sulphuric anhydrate can be perceived during the
action of the monohydrate upon the pyrosulphate at the temperatures used in
processes of sulphonization.
The reaction that takes place between the substance to be sulphonated and the
pyrosulphate varies according to the temperature at which the reaction is going on,
and as an example I give the formulas for the sodium salts of anthraquinone
sulphonic acid, or in other words, the anthraquinone sulphonic acid salts of soda.
1. C, H, O² +
2.-014, H8, 02 +
S², 07, Na²
S2, 07, Na²
-
C14, H7, O², SO3, Na + SO, Na, H.
C, H, O2, (SO³, Na), + H2, O.
At temperatures not above 180° centigrade the process appears to go on
essentially as shown in the first of the before written formulas, and at higher
temperatures, as shown in the second formula.
By this new process after the steps of sulphonating and of dissolving in water
the product of the reaction have been accomplished, and after the free sulphuric
acid has been neutralized by milk of lime, and the liquid has been separated by
filtration and pressure from the precipitated sulphate of lime, I obtain direct the
alkali salts of the sulphonic acids, from the solution of which the small quantity
of unprecipitated sulphate of lime which will still remain therein in consequence
of the slight solubility of the latter must be removed by soda.
As example I give the special directions for the production of,-
1. Anthraquinone-monosulphonate and Anthraquinone-disulphonate of Soda.
10/10 parts of pyrosulphate of soda in fine powder are introduced into 20 parts
of sulphuric acid monohydrate, and the mixture is maintained at about 180°
centegrade, and kept stirred all the time until the greatest part of the pyrosulphate
of soda is dissolved. Then I allow it to cool down to about 120 centigrade, and

page_text: add by portions at short intervals 10 parts of well dried anthraquinone. On
heating further to from 220° to in maximo 230 centigrade there is formed,
according to the temperature applied, more mono- or more disulphonic acid salt,
that is to say, there is formed a larger proportion of the former at the lower and a
larger proportion of the latter at the higher degrees of said range or interval of
temperature.
After finishing the heating I pour the whole products and residues of the reaction
into water, neutralize the free sulphuric acid carefully with milk of lime, separate
out by pressure the precipitated sulphate of lime, wash with water, precipitate the
dissolved sulphate of lime from the hot liquid with a little soda, and evaporate
the liquid (after it has been allowed to settle and clear) to the desired degree.of
concentration.
and as Homologues.
10 parts of well dried sulphate of amido-azo benzol are added to 30 parts of
sulphuric acid monohydrate, and the mixture is heated on the waterbath until
solution takes place. Afterwards I add 12 parts of well powdered pyrosulphate
of soda in 4 portions, and I digest the whole on the water bath at about
98° centigrade with constant stirring.
According to the duration of the reaction I obtain the soda salt of the disul-
phonic acid which is soluble in water, or the soda salt of the monosulphonic acid
which is with difficulty soluble in water. To obtain the former I digest the
mixture (containing, as above mentioned, 12 parts of pyrosulphate) for about two
hours until a sample gives a clear solution in water, whereas to produce the latter
I use only half of the above named quantity of pyrosulphate, and I digest at
100° centigrade until a sample gives a clear solution in ammonia only.
The further treatment of the product is the same as described with regard to the
soda salts of the anthraquinone sulphonic acids.
All that has been said with regard to the formation and the production of the
sulphonic salts of soda applies also to the sulphonic salts of potash.
The proportions and also the degrees of temperature herein before prescribed may
be varied within certain limits.
Having thus described and particularly ascertained the nature of the said
Invention, and the manner of performing the same, I explain that what I claim
as my Invention is the production of the alkali salts (1) of the mono and disul-
phonic acids of anthraquinone, (2) of the sulphonic acids of rosaniline, and (3) of
the mono and disulphonic acids of amido-azo benzol and its homologues by acting
on anthraquinone, rosaniline, and amido-azo benzol, or its homologues respectively

page_text: with pyrosulphate of soda or of potash (preferably dissolved in monohydrated
sulphuric acid) in the manner hereinbefore described, or in manner substantially
the same as herein before described.
In witness whereof, I, the said Joseph Anthony Dixon, have hereunto set my
hand and seal, this Twenty seventh day of May, in the year of our Lord
One thousand eight hundred and eighty one.
J. A. DIXON. (L.S.)