OBTAINING COLOURING MATTERS SUITABLE FOR DYEING AND PRINTING
Year: 1876

page_text: T
A
LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
"IMPROVEMENTS IN
County of Middlesex, Gentleman, for the Invention of
OBTAINING COLOURING MATTERS SUITABLE FOR DYEING AND PRINTING."
communication from abroad by Heinrich Caro, of Mannheim, in the Empire
of Germany, Chemist to the Badische Anilin and Soda Fabrik, of Mannheim,
aforesaid (Grand Duchy of Baden).
Sealed the 23rd May 1876, and dated the 22nd March 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 22nd March 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN OBTAINING COLOURING MATTERS SUITABLE FOR
DYEING AND PRINTING." A communication from abroad by Heinrich Caro, of
Mannheim, in the Empire of Germany, Chemist to the Badische Anilin and Soda
Fabrik, of Mannheim, aforesaid (Grand Duchy of Baden).
This Invention relates to improvements in preparing colouring matters suitable
for dyeing and printing from pure or commercial alizarine.
Alizarine, as is well known to chemists, is easily acted on by nitric acid, the result
being either complete destruction of its molecules, or the production of an unstable
nitro compound, which by the action of water or alkalies, is rapidly converted into
nitro-oxy-alizarine, a colouring matter possessing properties similar to purpurine.
It is only by a circuitous manner, namely, by firstly converting alizarine into its
diacetyl compound, and subsequently treating the same with nitroic acid, or by
submitting textile fabrics dyed or printed with alizarine reds to the action of
nitrous vapours or of nitric acid, and afterwards extracting the colouring matter,
which has undergone alteration therefrom, that colouring matters or nitro com-
pounds of alizarine have been obtained, which differ from the above-mentioned
unstable product by being capable of imparting a permanent orange red dye to
alumina mordants.
According to my present Invention similar colouring matter or matters which I pro-
pose to term "alizarine orange," may be produced in a direct manner from alizarine
itself;
such alizarine being employed either in its pure state or in the commercial con-
dition in which the various preparations from madder, or the artificial alizarines
synthetically prepared from coal tar are delivered to the trade, and which
Price &dl
-

page_text: products contain besides alizarine more or less other compounds, such as iso-
purpurine, anthra-purpurine, or purpurine; all such preparations I hereafter call
commercial alizarine;" the said pure or commercial alizarine may, according to
my Invention, be converted into alizarine orange by the action of nitrous hyponitric
or nitric acids, such acids being used for this purpose either in. their free state
singly or mixed with one another, or such as result from the mutual decomposition
of any saline compound of the same with any other acid or acids, mineral or
organic, which are capable of liberating the said nitrogen acids from their saline
compounds.
This Invention may be carried out in the following manner:-Pure or com-
mercial alizarine, preferably dry, and in a fine state of division is spread out in thin
layers and exposed in a closed chamber or otherwise, to the action of nitrous,
hyponitric, or nitric acids, such acids being employed in a gaseous condition, and
either singly or mixed with one another; and I allow the action to proceed at the
ordinary atmospheric temperature, or at an elevated temperature, until the desired
change has been accomplished. This result may be ascertained by withdrawing a
sample of the product from time to time, and by testing it for the presence of
unaltered alizarine therein by any of the well-known methods generally used for
that purpose. If, for instance, tested with caustic alkalies, the purple solution of
the alkaline alizarates is no longer obtainable, the operation may be considered at
an end, and the alizarine orange should be withdrawn from the further action of
the nitrogen acids. The same colouring matter may also be obtained by mixing pure
or commercial alizarine with or dissolving it in a suitable solvent, which solvent is
not easily acted on by the nitrogen acids, such as ether, glacial acetic acid, sulphide
of carbon, benzole, petroleum, nitro-benzol, or similar substances or mixtures of two
or more of them; and the mixture or solutions thus obtained I treat with nitrous
acid, hyponitric acid, or nitric acid, either singly or mixed with ono another at the
ordinary atmospheric temperature, or at an elevated temperature, until the produc-
tion of the alizarine orange is complete or nearly so. In every instance due care is
to be taken to avoid any excess of the nitrogen acids, as such an excess would carry
the action too far and have the ultimate effect of destroying the desired product.
The result of this operation is then freed from the solvents employed by filtration
or otherwise, and ultimately washed and dried. The alizarine orange obtained by
the above described methods may, if desired, be converted into a paste by dis-
solving it in diluted caustic or carbonated alkalies, and precipitating the solutions
thus obtained by a suitable acid. The precipitate is collected on filters, and after
being well washed it is a coloring matter suitable for dyeing and printing.
A further purification of the alizarine orange may be effected in various ways, as
for instance, by adding an excess of caustic potash, or soda solution to its alkaline
solution, and by redissolving the precipitate thus produced in water, and decom-
posing the solution by a suitable acid, when the purified coloring matter will be
again precipitated, and may be filtered and washed as above stated.
a
Another process of producing coloring matters similar to the above-mentioned
alizarine orange, according to my Invention, consists in dissolving pure or commer-
cial alizarine in concentrated sulphuric acid, and treating the solution at the ordinary
atmospheric temperature with nitrous, hyponitric, or nitric acids, or with
corresponding quantity of any saline compound of the same, the action of these
acids or compounds being allowed to continue with due care to avoid rise of tem-
perature, until the solution no longer contains any unaltered alizarine or nearly so.
The mixture is then mixed with a large quantity of cold water and the precipitate
obtained filtered and well washed. A further purification of the coloring matter
may be arrived at by the methods before described.
According to another portion of my Invention, a coloring matter possessing the
properties of purpurinė may be obtained as follows:-Upon dissolving the coloring
matter obtained by the last-named process in concentrated sulphuric acid, and by
gradually raising the temperature of the solution a vivid evolution of gas ensues,
chiefly consisting of nitrogen, upon the cessation of which the solution will be found

page_text: to contain the coloring matter possessing the properties of purpurine, which coloring
matter may be obtained in a state suitable for dyeing and printing, by mixing tho
acid solution with water, and filtering and washing the precipitate thus obtained,
which may or may not be further purified by the well-known methods for preparing
pure purpurine. A similar result may be obtained by treating the sulphuric acid
solution of pure or commercial alizarine with nitrous hyponitric or nitric acids, in
the manner above described, until the production of alizarine orange is complete or
nearly so, and afterwards raising the temperature of the solution until the evolution
of gas has ceased, and the formation of purpurine is perfect, or nearly so. I then
apply the methods above described for obtaining purpurine in a state suitable for
dyeing and printing.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 12th
September 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. 86 IMPROVEMENTS IN OBTAINING COLORING MATTERS SUITABLE FOR
DYEING AND PRINTING." A communication from abroad by Heinrich Caro, of
Mannheim, in the Empire of Germany, Chemist to the Badische Anilin and Soda
Fabrik, of Mannheim, aforesaid (Grand Duchy of Baden).
This Invention relates to improvements in preparing coloring matters suitable for
dyeing and printing from pure or commercial "alizarine."
Alizarine, as is well known to chemists, is easily acted upon by nitric acid, the
result being either complete destruction of its molecule or the production of an
unstable nitro compound, which by the action of water or alkalies is rapidly con-
verted into nitro oxyalizarine, a coloring matter possessing properties similar to
purpurine. It is only by a circuitous manner, namely, by firstly converting
alizarine into its diacetyl compound, and subsequently treating the same with nitric
acid, or by submitting textile fabrics, dyed or printed with alizarine reds, to the
action of nitrous vapours or of nitric acid, and afterwards extracting the coloring
natter which has undergone alteration therefrom, that coloring matters or nitro
compounds of alizarine have been obtained which differ from the above-mentioned
unstable product by being capable of imparting a permanent orange red dye to
alumina mordants.
According to my present Invention similar coloring matter or matters, which I
propose to term "alizarine orange," may be produced in a direct manner from
alizarine itself, such alizarine being employed either in its pure state or in the coin-
mercial condition in which the various preparations from inadder, or the artificial
alizarine synthetically prepared from coal-tar are delivered to the trade, and which
products contain besides alizarine, more or less, other compounds, such as iso-
purpurine, anthra-purpurine or purpurine; all such preparations I hereafter call " com-
mercial alizarine"; the said pure or commercial alizarine may, according to my
Invention, be converted into "alizarine orange" by the action of nitrous hyponitric
or nitric acids, such acids being used for this purpose either in their free state singly
or mixed with one another, or such as result from the mutual decomposition of any
saline compound of the same with any other acid or acids, mineral or organic, which
are capable of liberating the said nitrogen acids from their saline compounds.
This Invention may be carried out in the following manner:-Pure or commercial
alizarine, preferably dry and in a fine state of division, is spread out in thin layers
and exposed in a closed chamber or otherwise, to the action of nitrous, hyponitric, or
nitric acid, such acids being employed in a gaseous condition and either singly or
mixed with one another, but I generally prefer their gascous mixture, practically
known as nitrous fumes, resulting as a bye product froin various processes in which
nitric acid is omployed as an oxidizing agent. I then allow the action to proceed at

page_text: the ordinary atmospheric temperature or at an elevated temperature until the
desired change has been accomplished. This result may be ascertained by with-
drawing a sample of the product from time to time and by testing it for the pre-
sence of unaltered alizarine therein by any of the well-known methods generally
used for that purpose. If, for instance, tested with caustic alkalies, the purple solu-
tion of the alkaline alizarates is no longer obtainable the operation may be considered
at an end, and the alizarine orange should be withdrawn from the further action of
the nitrogen acids. The same coloring matter may also be obtained by mixing pure
or commercial alizarine with or dissolving it in a suitable solvent, which solvent is
not easily acted on by the nitrogen acids, such as ether, glacial acetic acid, bisulphide
of carbon, benzole, petroleum, nitro benzole, or similar substances, or mixtures of
two or more of them, and the mixture or solutions thus obtained I treat with
nitrous acid. Hyponitric acid or nitric acid, either singly or mixed with one another
at the ordinary atmospheric temperature, or at an elevated temperature, until the
production of the alizarine orange is complete, or nearly so. In every instance due
care is to be taken to avoid the employment of any excess of the nitrogen acids as
such an excess would carry the action too far and have the ultimate effect of destroy-
ing the desired product. As an example, I proceed as follows:-I take a cold and
saturated solution of alizarine in sulphuric ether, and I allow a current of nitrous
acid to pass through it for some time, until a crystallization takes place consisting
of small shining scales of the alizarine orange in an almost chemically pure con-
dition.
By another method I dissolve one part by weight of alizarine in about twenty parts
by weight of nitro benzole at a temperature of about 120 degrees centigrade, and
this solution, whilst being kept heated, I heat with a current of nitrous acid until
no more absorption of the gas takes place and the mixture no longer contains any
appreciable quantity of unaltered alizarine. The alizarine orange may then be
separated from the nitro benzole by removing the latter by distillation, or the mix-
ture may be agitated with an aqueous solution of caustic or carbonated alkali until
the coloring matter has been withdrawn from its solution in nitro benzole. The
alkaline compound of the alizarine orange is afterwards decomposed by a suitable
acid, then filtered and washed.
Another method for effecting the conversion of alizarine into alizarine orange by
means of nitrous or hyponitric acids, and in presence of a suitable solvent, is the
following I take about one part by weight of alizarine in a finely divided condi-
tion, which is intimately mixed with about thirty parts by weight of benzole, and
the mixture is then heated to ebullition in a suitable vessel or apparatus, (by prefer-
ence in an earthenware distillatory apparatus provided with a condensing arrange-
ment in such a manner that the benzole is constantly made to run back into the
vessel. I then pass the gaseous mixture of nitrous and hyponitric acids into and
through the boiling mixture of alizarine and benzole until the conversion of the
former into alizarine orange is complete or nearly so. I then allow the mixture to
cool and separate the alizarine orange from the benzole by filtration. The benzole,
which has served for this operation can afterwards be conveniently used for a
series of similar operations, or it may be recovered by distillation.
The following process I give as an example to illustrate the conversion of alizarine
into alizarine orange by means of nitric acid acting in presence of a suitable solvent
of alizarine About two parts by weight of alizarine are mixed with about 20
(twenty) parts by weight of glacial acetic acid, and with about 1/2 (one and a half)
parts by weight of nitric acid of about 138 specific gravity, which are added by
small portions at a time. The mixture is then allowed to remain tranquil for about
twenty-four hours at the ordinary temperature, or I accelerate the action by
employing a somewhat higher temperature, say from about 30 to 50 degrees centi-
grade. In this process the glacial aocetic acid may be replaced by other suitable
solvents of alizarine, such as petroleum, hydrocarbons, benzole or its homologues, a
nitro benzole, bisulphide of carbon. The result of this operation is then freed from
the solvents employed by filtration or otherwise, and ultimately washed and dried.

page_text: The alizarine orange obtained by the above-described methods may, if desired, be
converted into a paste by dissolving it in diluted caustic or carbonated alkalies, and
precipitating the solutions thus obtained by a suitable acid. The precipitate is collected
on filters, and after being well washed it is a coloring matter suitable for dyeing and
printing.
A further purification of the alizarine orange may be effected in various ways,
as for instance, by adding an excess of caustic potash or soda solution to its
alkaline solution and by re-dissolving the precipitate thus produced in water and
decomposing the solution by a suitable acid, when the purified colouring matter
will be again precipitated, and may be filtered and washed as above stated.
Another process for producing colouring matter similar to the above-mentioned
alizarine orange, according to my Invention, consists in dissolving pure or commercial
alzarine in concentrated sulphuric acid, and treating the solution at the ordinary
atmospheric temperature with nitrous, hyponitric, or nitric acids, or with a corre-
sponding quantity of any saline compound of the same, the action of these acids or
compounds being allowed to continue with duc care to avoid rise of temperature
until the solution no longer contains any or but little unaltered alizarine. As an
example I proceed as follows:-I take about 10 parts by weight of alizarine which
are dissolved in about 50 parts by weight of sulphuric acid of about 1848 specific
gravity, and this mixture is afterwards cooled down to a temperature of about
zero, and by preference not higher than 10 degrees centigrade. I then add in
small portions from time to time and with due care so as to avoid any rise of
temperature, a well cooled mixture of 8 parts (by weight) of sulphuric acid of
about 1848 specific gravity. The mixture is then mixed with with a large quantity
of cold water, and the precipitate obtained filtered and well washed. A further
purification of the colouring matter may be arrived at by the methods before
described.
According to a further portion of my Invention a coloring matter possessing the
properties of purpurine may be obtained as follows:-Upon dissolving one part by
weight of the colouring matter obtained by the last named process in about 10
parts by weight of concentrated sulphuric acid of about 1-848 specific gravity, and
by gradually raising the temperature of the solution to about 150 degrees centigrade
an evolution of gas ensues, chiefly consisting of nitrogen, upon the cessation of
which the solution will be found to contain the colouring matter possessing the
properties of purpurine, which coloring may be obtained in a state suitable for
dyeing and printing by mixing the acid solution with water and filtering and
washing the precipitate thus obtained, which may or may not be further purified by
the well known methods for preparing pure purpurine, as, for example, by dissolving
the coloring matter in a boiling and concentrated aqueous solution of alum, and by
precipitating the colouring matter from the filtered solution by means of a mineral
acid. A similar result may be obtained by treating the sulphuric acid solution of
pure or commercial alizarine with nitrous hyponitric or nitric acids in the manner
above described until the production of alizarine orange is complete, or nearly so,
and afterwards raising the temperature of the solution until the evolution of gas
has ceased and the formation of purpurine is perfect, or nearly so.
I then apply
the methods above described for obtaining purpurine in a state suitable for dyeing
and printing.
I wish it to be understood that I do not confine myself to the proportions,
weights, periods, or temperatures herein-before stated, as such may be varied, but
the processes described will be found practically to serve as examples for carrying
out the Invention.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or 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 herein-before in part
recited Letters Patent, is,―
First. The production of alizarine orange by the action cf either nitrous or of

page_text: hyponitric acids, or mixtures of the same upon either pure or upon commercial
alizarine, the same being obtained either from natural sources or produced artificially,
and such alizarine or alizarines being employed either in their dried condition or
mixed with or dissolved in a suitable solvent not easily acted upon by the nitrogen
and other acids employed.
Second. The production of alizarine orange by means of nitric acid acting in
the presence of a suitable solvent upon pure or upon commercial alizarine, in the
manner herein-before described.
Third. In the production of an alizarine orange from either pure or from com-
mercial alizarine by firstly dissolving the same in concentrated sulphuric acid and
then treating the solution with either nitrous hyponitric or nitric acids, or with
mixtures of the same, in the manner herein-before described.
Fourth. In the production of a colouring matter possessing the properties of
purpurine by dissolving alizarine orange obtained by the process described in the
third claim of this Specification in concentrated sulphuric acid and then gradually
raising the temperature of such solution, in the manner herein-before described.
Fifth. In the production of a colouring matter possessing the properties of
purpurine by treating either pure or commercial alizarine dissolved in concentrated
sulphuric acid and then submitting such solution to the action of either nitrous
hyponitric or nitric acids, or mixtures of the same, so as to produce alizarine
orange, and subsequently raising the temperature of such solution so as to produce
the desired colouring matter, in the manner herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, the Twelfth day of September, One thousand
eight hundred and seventy-six.
J. HENRY JOHNSON. (L.S.)

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
OBTAINING COLOURING MATTERS SUITABLE FOR DYEING AND PRINTING." A
communication from abroad by Heinrich Caro, of Mannheim, in the Empire of
Germany, Chemist to the Badische Anilin and Soda Fabrik, of Mannlicim,
aforesaid (Grand Duchy of Baden).
Sealed the 23rd May 1876, and dated the 22nd March 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 22nd March 1876.
14
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleinan. IMPROVEMENTS IN OBTAINING COLOURING MATTERS SUITABLE FOR
DYEING AND PRINTING." A communication from abroad by Heinrich Caro, of
Mannheim, in the Empire of Germany, Chemist to the Badische Anilin and Soda
Fabrik, of Mannheim, aforesaid (Grand Duchy of Baden).
This Invention relates to improvements in preparing colouring matters suitable
for dyeing and printing from pure or commercial alizarine.
Alizarine, as is well known to chemists, is easily acted on by nitric acid, the result
being either complete destruction of its molecules, or the production of an unstablo
nitro compound, which by the action of water or alkalies is rapidly converted into
nitro-oxyalizarine, a colouring matter possessing properties similar to purpurine.
It is only by a circuitous manner, namely, by firstly converting alizarine into its
diacetyl compound, and subsequently treating the same with nitroic acid, or by
submitting textile fabrics dyed or printed with alizarine reds to the action of
nitrous vapours or of nitric acid, and afterwards extracting the colouring matter,
which has undergone alteration therefrom, that colouring matters or nitro com-
pounds of alizarine have been obtained, which differ from the above-mentioned
unstable product by being capable of imparting a permanent orange red dye to
alumina mordants.
According to my present Invention similar colouring matter or matters which I pro
pose to term "alizarine orange," may be produced in a direct manner from alizarine
itself; such alizarine being employed either in its pure state or in the commercial con-
dition in which the various preparations from madder, or the artificial alizarines
synthetically prepared from coal tar are delivered to the trade, and which

page_text: products contain besides alizarine more or less other compounds such as iso-
purpurine, anthra-purpurine, or purpurine; all such preparations I hereafter call
commercial alizarine;" the said pure or commercial alizarine may, according to
my Invention, be converted into alizarine orange by the action of nitrous, hyponitric,
or nitric acids, such acids being used for this purpose either in their free state
singly or mixed with one another, or such as result from the mutual decomposition
of any saline compound of the same with any other acid or acids, mineral or
organic, which are capable of liberating the said nitrogen acids from their saline
compounds.
This Invention may be carried out in the following manner:-Pure or com-
mercial alizarine, preferably dry, and in a fine state of division is spread out in thin
layers, and exposed in a closed chamber or otherwise to the action of nitrous,
hyponitric, or nitric acids, such acids being employed in a gaseous condition, and
either singly or mixed with one another; and I allow the action to proceed at the
ordinary atmospheric temperature, or at an elevated temperature, until the desired
change has been accomplished. This result may be ascertained by withdrawing a
sample of the product from time to time, and by testing it for the presence of
unaltered alizarine therein by any of the well known methods generally used for
that purpose. If, for instance, tested with caustic alkalies the purple solution of
the alkaline alizarates is no longer obtainable the operation may be considered at
an end, and the alizarine orange should be withdrawn from the further action of
the nitrogen acids. The same colouring matter may also be obtained by mixing pure
or commercial alizarine with or dissolving it in a suitable solvent, which solvent is
not easily acted on by the nitrogen acids, such as ether, glacial acetic acid, sulphide
of carbon, benzole, petroleum, nitro-benzol, or similar substances or mixtures of two
or more of them; and the mixture or solutions thus obtained I treat with nitrous
acid, hyponitric acid, or nitric acid, either singly or mixed with one another at the
ordinary atmospheric temperature, or at an elevated temperature, until the produc-
tion of the alizarine orange is complete or nearly so. In every instance due care is
to be taken to avoid any excess of the nitrogen acids, as such an excess would carry
the action too far, and have the ultimate effect of destroying the desired product.
The result of this operation is then freed from the solvents employed by filtration
or otherwise, and ultimately washed and dried. The alizarine orange obtained by
the above described methods may, if desired, be converted into a paste by dis-
solving it in diluted caustic or carbonated alkalies, and precipitating the solutions
thus obtained by a suitable acid. The precipitate is collected on filters, and after
being well washed it is a coloring matter suitable for dyeing and printing.
A further purification of the alizarine orange may be effected in various ways, as
for instance, by adding an excess of caustic potash or soda solution to its alkaline
solution, and by redissolving the precipitate thus produced in water, and decom-
posing the solution by a suitable acid, when the purified coloring matter will be
again precipitated, and may be filtered and washed as above stated.
Another process of producing coloring matters similar to the above-mentioned
alizarine orange, according to my Invention, consists in dissolving pure or commer-
cial alizarine in concentrated sulphuric acid, and treating the solution at the ordinary
atmospheric temperature with nitrous, hyponitric, or nitric acids, or with a
corresponding quantity of any saline compound of the same, the action of these
acids or compounds being allowed to continue with due care to avoid rise of tem-
perature, until the solution no longer contains any unaltered alizarine or nearly so.
The mixture is then mixed with a large quantity of cold water, and the precipitate
obtained filtered and well washed. A further purification of the coloring matter
may be arrived at by the methods before described.
According to another portion of my Invention, a coloring matter possessing the
properties of purpurine may be obtained as follows:-Upon dissolving the coloring
matter obtained by the last-named process in concentrated sulphuric acid, and by
gradually raising the temperature of the solution a vivid evolution of gas ensues,
chiefly consisting of nitrogen, upon the cessation of which the solution will be found

page_text: to contain the coloring matter possessing the properties of purpurine, which coloring
matter may be obtained in a state suitable for dyeing and printing, by mixing the
acid solution with water, and filtering and washing the precipitate thus obtained,
which may or may not be further purified by the well-known methods for preparing
pure purpurine. A similar result may be obtained by treating the sulphuric acid
solution of pure or commercial alizarine with nitrous, hyponitric, or nitric acids, in
the manner above described, until the production of alizarine orange is complete or
nearly so, and afterwards raising the temperature of the solution until the evolution
of gas has ceased, and the formation of purpurine is perfect, or nearly so. I then
apply the methods above described for obtaining purpurine in a state suitable for
dyeing and printing.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 12th
September 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN OBTAINING COLORING MATTERS SUITABLE FOR
DYEING AND PRINTING." A communication from abroad by Heinrich Caro, of
Mannheim, in the Empire of Germany, Chemist to the Badische Anilin and Soda
Fabrik, of Mannheim, aforesaid (Grand Duchy of Baden).
This Invention relates to improvements in preparing coloring matters suitable for
dyeing and printing from pure or commercial "alizarine."
Alizarine, as is well known to chemists, is easily acted upon by nitric acid, the
result being either complete destruction of its molecule or the production of an
unstable nitro compound, which by the action of water or alkalies is rapidly con-
verted into nitro-oxyalizarine, a coloring matter possessing properties similar to
purpurine. It is only by a circuitous manner, namely, by firstly converting
alizarine into its diacetyl compound, and subsequently treating the same with nitric
acid, or by submitting textile fabrics, dyed or printed with alizarine reds, to the
action of nitrous vapours or of nitric acid, and afterwards extracting the coloring
matter which has undergone alteration therefrom, that coloring matters or nitro
compounds of alizarine have been obtained which differ from the above-mentioned
unstable product by being capable of imparting a permanent orange red dye to
alumina mordants.
According to my present Invention similar coloring matter or matters, which I
propose to term "alizarine orange," may be produced in a direct manner from
alizarine itself, such alizarine being employed either in its pure state or in the com-
mercial condition in which the various preparations from madder, or the artificial
alizarine synthetically prepared from coal tar are delivered to the trade, and which
products contain besides alizarine, more or less, other compounds, such as iso-
purpurine, anthra-purpurine or purpurine; all such preparations I hereafter call "com-
mercial alizarine;" the said pure or commercial alizarine may, according to my
Invention, be converted into "alizarine orange" by the action of nitrous, hyponitric,
or nitric acids, such acids being used for this purpose either in their free state singly
or mixed with one another, or such as result from the mutual decomposition of any
saline compound of the same with any other acid or acids, mineral or organic, which
are capable of liberating the said nitrogen acids from their saline compounds.
This Invention may be carried out in the following manner :-Pure or commercial
alizarine, perferably dry and in a fine state of division, is spread out in thin layers
and exposed in a closed chamber or otherwise, to the action of nitrous, hyponitric, or
nitric acids, such acids being employed in a gaseous condition and either singly or
mixed with one another, but I generally prefer their gaseous mixture, practically
known as nitrous fumes, resulting as a bye product from various processes in which
nitric acid is employed as an oxidizing agent. I then allow the action to proceed at

page_text: the ordinary atmospheric temperature or at an elevated temperature until the
desired change has been accomplished. This result may be ascertained by with-
drawing a sample of the product from time to time and by testing it for the pro-
sence of unaltered alizarine therein by any of the well-known methods generally
used for that purpose. If, for instance, tested with caustic alkalies, the purple solu-
tion of the alkaline alizarates is no longer obtainable the operation may be considered
at an end, and the alizarine orange should be withdrawn from the further action of
the nitrogen acids. The same coloring matter may also be obtained by mixing pure
or commercial alizarine with or dissolving it in a suitable solvent, which solvent is
not easily acted on by the nitrogen acids, such as ether, glacial acetic acid, bisulphide
of carbon, benzole, petroleum, nitro benzole, or similar substances, or mixtures of
two or more of them, and the mixture or solutions thus obtained I treat with
nitrous acid, hyponitric acid, or nitric acid, either singly or mixed with one another
at the ordinary atmospheric temperature, or at an elevated temperature, until the
production of the alizarine orange is complete, or nearly so. In every instance due
care is to be taken to avoid the employment of any excess of the nitrogen acids as
such an excess would carry the action too far and have the ultimate effect of destroy-
ing the desired product. As an example, I proceed as follows:-I take a cold and
saturated solution of alizarine in sulphuric ether, and I allow a current of nitrous
acid to pass through it for some time, until a crystallization takes place consisting
of small shining scales of the alizarine orange in an almost chemically pure con-
dition.
By another method I dissolve one part by weight of alizarine in about twenty parts
by weight of nitro benzole at a temperature of about 120 degrees centigrade, and
this solution, whilst being kept heated, I heat with a current of nitrous acid until
no more absorption of the gas takes place and the mixture no longer contains any
appreciable quantity of unaltered alizarine. The alizarine orange may then be
separated from the nitro benzole by removing the latter by distillation, or the mix-
ture may be agitated with an aqueous solution of caustic or carbonated alkali until
the coloring matter has been withdrawn from its solution in nitro benzole. The
alkaline compound of the alizarine orange is afterwards decomposed by a suitable
acid, then filtered and washerl.
Another method for effecting the conversion of alizarine into alizarine orange by
means of nitrous or hyponitric acids, and in presence of a suitable solvent, is the
following I take about one part by weight of alizarine in a finely divided condi-
tion, which is intimately mixed with about thirty parts by weight of benzole, and
the mixture is then heated to ebullition in a suitable vessel or apparatus, (by prefer-
ence in an earthenware distillatory apparatus provided with a condensing arrange-
ment in such a manner that the benzole is constantly made to run back into the
vessel. I then pass the gaseous mixture of nitrous and hyponitric acids into and
through the boiling mixture of alizarine and benzole until the conversion of the
former into alizarine orange is complete or nearly so. I then allow the mixture to
cool and separate the alizarine orange from the benzole by filtration. The henzole,
which has served for this operation can afterwards be conveniently used for a
series of similar operations, or it may be recovered by distillation.
The following process I give as an example to illustrate the conversion of alizarine
into alizarine orange by means of nitric acid acting in presence of a suitable solvent.
of alizarine About two parts by weight of alizarine are mixed with about 20
(twenty) parts by weight of glacial acetic acid, and with about 1/2 (one and a half)
parts by weight of nitric acid of about 1:38 specific gravity, which are added by
small portions at a time. The mixture is then allowed to remain tranquil for about
twentry-four hours at the ordinary temperature, or I accelerate the action by
employing a somewhat higher temperature, say from about 30 to 50 degrees centi-
grade. In this process the glacial aocetic acid may be replaced by other suitable
solvents of alizarine, such as petroleum, hydrocarbons, benzole or its homologues,
nitro benzole, bisulphide of carbon. The result of this operation is then freed from
the solvents employed by filtration or otherwise, and ultimately washed and dried.

page_text: The alizarine orange obtained by the above-described methods may, if desired, be
converted into a paste by dissolving it in diluted caustic or carbonated alkalies, and
precipitating the solutions thus obtained by a suitable acid. The precipitate is collected
on filters, and after being well washed it is a coloring matter suitable for dyeing and
printing.
A further purification of the alizarine orange may be effected in various ways,
as for instance, by adding an excess of caustic potash or soda solution to its
alkaline solution and by re-dissolving the precipitate thus produced in water and
decomposing the solution by a suitable acid, when the purified colouring matter
will be again precipitated, and may be filtered and washed as above stated.
Another process for producing colouring matter similar to the above-mentioned
alizarine orange, according to my Invention, consists in dissolving pure or commercial
alzarine in concentrated sulphuric acid, and treating the solution at the ordinary
atmospheric temperature with nitrous, hyponitric, or nitric acids, or with a corre-
sponding quantity of any saline compound of the same, the action of these acids or
compounds being allowed to continue with due care to avoid rise of temperature
until the solution no longer contains any or but little unaltered alizarine. As an
example I proceed as follows:-I take about 10 parts by weight of alizarine which
are dissolved in about 50 parts by weight of sulphuric acid of about 1-848 specific
gravity, and this mixture is afterwards cooled down to a temperature of about
zero, and by preference not higher than 10 degrees centigrade. I then add in
small portions from time to time and with due care so as to avoid any rise of
temperature, a well cooled mixture of 8 parts (by weight) of nitric acid of about 1.38
specific gravity with about forty parts (by weight) of sulphuric acid of about 1.848
specific gravity. The mixture is then mixed with with a large quantity of cold
water, and the precipitate obtained filtered and well washed. A further purification
of the colouring matter may be arrived at by the methods before described.
According to a further portion of my Invention a coloring matter possessing the
properties of purpurine may be obtained as follows:-Upon dissolving one part by
weight of the colouring matter obtained by the last named process in about 10
parts by weight of concentrated sulphuric acid of about 1848 specific gravity, and
by gradually raising the temperature of the solution to about 150 degrees centigrade
an evolution of gas ensues, chiefly consisting of nitrogen, upon the cessation of
which the solution will be found to contain the colouring matter possessing the
properties of purpurine, which coloring may be obtained in a state suitable for
dyeing and printing by mixing the acid solution with water and filtering and
washing the precipitate thus obtained, which may or may not be further purified by
the well known methods for preparing pure purpurine, as, for example, by dissolving
the coloring matter in a boiling and concentrated aqueous solution of alum, and by
precipitating the colouring matter from the filtered solution by means of a mineral
acid. A similar result may be obtained by treating the sulphuric acid solution of
pure or commercial alizarine with nitrous, hyponitric, or nitric acids in the manner
above described until the production of alizarine orange is complete, or nearly so,
and afterwards raising the temperature of the solution until the evolution of gas
has ceased and the formation of purpurine is perfect, or nearly so.
I then apply
the methods above described for obtaining purpurine in a state suitable for dyeing
and printing.
I wish it to be understood that I do not confine myself to the proportions,
weights, periods, or temperatures herein-before stated, as such may be varied, but
the processes described will be found practically to serve as examples for carrying
out the Invention.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or 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 herein-before in part
recited Letters Patent is,-
First. The production of alizarine orange by the action of either nitrous or of

page_text: hyponitric acids, or mixtures of the same upon either pure or upon commercial
alizarine, the same being obtained either from natural sources or produced artificially,
and such alizarine or alizarines being employed either in their dried condition or
mixed with or dissolved in a suitable solvent not easily acted upon by the nitrogen
and other acids employed.
Second. The production of alizarine orange by means of nitric acid acting in
the presence of a suitable solvent upon pure or upon commercial alizarine, in the
manner herein-before described.
Third. In the production of an alizarine orange from either pure or from com-
mercial alizarine by firstly dissolving the same in concentrated sulphuric acid and
then treating the solution with either nitrous, hyponitric, or nitric acids, or with
mixtures of the same, in the manner herein-before described.
Fourth. In the production of a colouring matter possessing the properties of
purpurine by dissolving alizarine orange obtained by the process described in the
third claim of this Specification in concentrated sulphuric acid and then gradually
raising the temperature of such solution, in the manner herein-before described.
Fifth. In the production of a colouring matter possessing the properties of
purpurine by treating either pure or commercial alizarine dissolved in concentrated
sulphuric acid and then submitting such solution to the action of either nitrous,
hyponitric, or nitric acids, or mixtures of the same, so as to produce alizarine
orange, and subsequently raising the temperature of such solution so as to produce
the desired colouring matter, in the manuer herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, the Twelfth day of September, One thousand
eight hundred and seventy-six.
J. HENRY JOHNSON. (L.s.)