IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL ALIZARINE
Year: 1881

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 MANUFACTURE OF ARTIFICIAL ALIZARINE."
A communication from abroad by Doctor Carl Koenig, of Höechst-am-Main, in
the Empire of Germany, a Director of the Farbwerke vorm: Meister. Lucius.
PROVISIONAL SPECIFICATION left by the said Joseph Anthony Dixon at
the Office of the Commissioners of Patents on the 17th May 1881.
JOSEPH ANTHONY DIXON, of 175, West George Street, Glasgow, in the County
of Lanark, North Britain, Solicitor. "IMPROVEMENTS IN THE MANUFACTURE OF
ARTIFICIAL ALIZARINE." [A communication from abroad by Doctor Carl Koenig,
of Höechst-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.]
The transformation of the anthraquinone sulphonic acids into artificial alizarine
is effected, as is well known, by heating to a high temperature or smelting" the
salts of these acids with caustic soda or caustic potash.
This process produces masses of "alizarine-smelt," which besides the colouring
matters which are formed and besides varying quantities of sulphites, sulphates,
and carbonates of the alkalis, contain principally free caustic soda or caustic
potash, according to the caustic alkali used in the " "smelting." Now instead of
following the ordinary practice of supersaturating with acids the aqueous solution
of the "alizarine-smelts," and then precipitating the colouring matter, I mix that
aqueous solution with lime water and so precipitate from the same the calcium
compounds of the alizarine (the so called lime lakes), which I separate from the
alkaline lyes by filtration or by other suitable means. I evaporate the alkaline
lyes thus obtained, remove from the same, on suitable concentration, the above
mentioned alkali salts by crystallization, destroy the organic substances remaining
in the mother lye by smelting with saltpetre or by blowing in air of a high

page_text: temperature, and I then recover therefrom, by further means well known to
chemists, the caustic soda or caustic potash, as the case may be.
Instead of lime I can with equal success use in my process baryta, strontian, or
magnesia, and also with slight and obvious alterations in the conditions of the
process I can also use the chlorides of lime, of barium, of strontium, of magnesium,
and other salts of the alkaline earths and of magnesia.
Instead of causing those substances, beforementioned as employed for the
formation of the alizarine lakes (which are insoluble in the alkaline lyes), to act as
aforesaid upon the finished smelts, I add the same with equal success to the
materials to be "smelted" before the smelting process begins, or I use in
the smelting process the corresponding salts of the anthraquinone sulphonic acids.
The precipitated lakes I decompose direct by acids or I treat them first with
alkalis or with alkali salts, in order to remove the impurities arising from the
precipitating agents which have been applied, and then I precipitate by acids the
artificial alizarine from the solutions thus prepared.

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
14th November 1881.
JOSEPH ANTHONY DIXON, of 175, West George Street, Glasgow, in the County
of Lanark, North Britain, Solicitor. "IMPROVEMENTS IN THE MANUFACTURE OF
ARTIFICIAL ALIZARINE." A communication from abroad by Doctor Carl Koenig,
of Hoechst-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.
(First.) The transformation of the anthraquinone sulphonic acids into artificial
alizarine is effected, as is well known, by heating to a high temperature or
smelting" these acids or their alkaline salts with caustic soda or caustic potash.
This process produces masses of "alizarine-smelt," which besides the colouring
matters that are formed and besides varying quantities of sulphites, sulphates, and
carbonates of the alkalis, contain principally free caustic soda or caustic potash,
according to the caustic alkali used in the "smelting." Now instead of following
the ordinary practice of precipitating the colouring matter by supersaturating the
aqueous solution of the "alizarine-smelts "with acids, such as sulphuric or hydro-
chloric acid, which produce in the alkaline liquors from which they precipitate the
alizarine a crop of salts of little utility or value, I mix that aqueous solution with
lime water and so precipitate the alizarine from the same in the form of the
calcium compounds of alizarine (the so called lime lakes of alizarine), which lakes
I separate from the alkaline lyes remaining after the precipitation by filtration or
by other suitable means. I evaporate the alkaline lyes thus obtained, remove from
the same, after suitable concentration, the above mentioned alkali salts by
crystallization, destroy the organic substances remaining in the mother lye by
sinelting with saltpetre or by blowing in air of a high temperature, and I then
recover therefrom, by further means well known to chemists, the caustic soda or
caustic potash, as the case may be. I thus avoid the deteriorating action on the
alkali salts and caustic alkalis contained in the aqueous solution of the "smelt" of
the acids ordinarily used to precipitate the alizarinė from said solution, and am
able to recover the said alkali salts and caustic alkalis by not exposing them to the
action of the said acids. The alizarine is, as hereinafter mentioned, separated from
the lake by acting on the lake after its separation from the solution of the "smelti
(directly or after further treatment with alkalis, as hereinafter mentioned) with the
acids which, according to the present method, are made not only to act on the
alkaline compound of alizarine in the said solution, but also on the alkaline salts
and alkalis contained along with the alizarate therein.
Instead of lime I can with equal success use in my process baryta, strontian, or
magnesia, and also with slight and obvious alterations in the conditions of the
process I can also use the chlorides of lime, of barium, of strontium, of magnesium,
and such other salts of the alkaline earths and of magnesia as will yield alizarino
compounds insoluble in the alkaline lyes.
(Second.) Instead of causing those substances, hereinbefore mentioned as em.
ployed or capable of being employed, for the formation of alizarine lakes insoluble
in the alkaline lyes, to act as aforesaid upon the finished "smelts," I add the same
with equal success to the materials to be "smelted" before the "smelting" process
begins, or I use in the smelting process the corresponding salts of the anthra-
quinone sulphonic acids.
In this way I get an alizarine lake or compound of
alizarine insoluble in the alkaline liquors obtained by dissolving the smelted mass
in water, from which luke the alizarine can be separated in manner hereinafter
described, and I treat the alkaline liquor which remains after separating the lake
so as to recover therefrom by evaporation, crystallization, and other methods
hereinbefore mentioned, the alkali salts and caustic alkalis contained therein.
The precipitated lakes I decompose direct by acids or I treat them first with

page_text: alkalis or with alkali salts, in order to remove the impurities arising from the
precipitating agents which have been applied, and then I precipitate by acids the
artificial alizarine from the solutions thus prepared.
In the terms "alizarine" or "artificial alizarine," I mean throughout this
Specification to include not only alizarine properly so called, but also the other
colouring matters usually accompanying it in the product of the ordinary process
for artificial alizarine, such as anthrapurpurin and Havopurpurin.
Having now described and particularly ascertained the nature of the said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the bereinbefore in part recited Letters Patent is,-
First. The process or method, hereinbefore described under head "First," of
treating the alkaline "alizarine-smelts" of the artificial alizarine manufacture,--such
process or method consisting in precipitating by means of lime or the other
substitutes therefor hereinbefore mentioned, and separating the alizarine from the
solution of the "smelt" in the form of an insoluble lake from which the alizarine
is afterwards separated, all in manner hereinbefore described, and in treating, in the
manner herein before described, the residual alkaline solution obtained by separating
the alizarine in the said manner, and form from the solution of the "smelt," so as
to recover from the said residual alkaline solution the alkali salts and caustic
alkalis contained therein.
Second. The process or method, herein before described under head "Second,"
which consists in the addition to or the use as an ingredient in or as one of the
components of the mass or magma to be smelted, of lime or any of the other
substances (including the herein before mentioned salts of the anthraquinone
sulphonic acids) hereinbefore mentioned as yielding after the smelting an alizarino
lake or compound of alizarine insoluble in the alkaline liquor obtained by dissolving
the smelted mass in water, and in the separation in manner hereinbefore described
of such lake from the said alkaline liquor, and the subsequent separation of the
alizarine from the said lake, and in the treatment, in manner hereinbefore described,
of the said alkaline liquor after the separation of the lake therefrom, so as to
recover from the said alkaline liquor the alkali salts and caustic alkalis contained
therein.
Third. Separatim. The general method exemplified in the processes claimed under
the two preceding heads of claim, of avoiding bringing the alkaline salts and
caustic alkalis contained in the alizarine "smelt" under the action of acids in order
to precipitate the alizarine, and of removing with the said view and purpose the
alizarine from the solution of the "sınelt in the form of an insoluble lako in
order to a separate treatment of the lake for recovery of the alizarine, the alkaline
liquors remaining after the separation of the lake being also separately treated for
recovery of the alkaline salts and caustic alkalis contained therein, and that
irrespective of how the lake may be produced, and of what special methods of
treatment may be applied to the separated lake and to the residual alkaline liquor
respectively for recovery of the alizarine and of the alkaline salts and caustic
alkalis respectively therefrom.
In witness whereof, I, the said Joseph Anthony Dixon, have hereunto set my
hand and seal, this Ninth day of November, in the year of our Lord One
thousand eight hundred and eighty one.
JOSEPH ANTHONY DIXON. (L.S.)