Improvements in the Manufacture of Colouring-matters Derived from Anthraquinone.
Year: 1892

page_text: Date of Application, 27th Jan., 1892
Complete Specification Left, 27th Oct., 1892-Accepted, 10th Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Colouring-matters Derived from
Anthraquinone.
1, BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Farbenfabriken vormals Friedrich
Bayer & Co. of Elberfeld in the Empire of Germany) to be as follows:-
In the Specifications of Letters Patent granted to me No. 12715 dated
13th August 1890, No. 17712 dated 4th November 1890, No. 18729 dated
19th November 1890 and in the Specifications of applications for Letters Patent
No. 4871 dated 18th March 1891 and No. 13677 dated 13th August 1891 it is
stated that certain tetra-hydroxyanthraquinones by treating them in sulphuric acid
solution with oxidising agents can be transformed into new valuable dye-stuffs
which dye blue with the aid of chromium mordants and which have been termed
"alizarin cyanines."
In the same manner alizarin bordeaux, purpurin bordeaux and anthrachryson
which are tetrahydroxyanthraquinones, likewise anthrapurpurine bordeaux and
flavo purpurine bordeaux which appear also to represent tetrahydroxyanthra-
quinones can by treatment with oxidising agents in sulphuric acid solution be
changed into so called alizarin-cyanines.
My foreign correspondents have now found that other tetrahydroxyanthra-
quinones especially oxyflavopurpurine and oxyanthrapurpurine which are described
in the Specification of Letters Patent No. 18729 granted to me and dated
November 19th 1890 yield when treated in sulphuric acid solution with manganese
dioxide or arsenic acid dye-stuffs belonging to the series of alizarin-cyanines.
In order to carry out this process either a somewhat higher temperature such as
from about 50 to 150 degrees centigrade or a greater quantity of the oxidising
agent is necessary in the latter case the reaction taking place commencing at from
about 25 to 30 degrees centigrade most practically in the presence of a greater
quantity of sulphuric acid than in analogous operations.
The following may be given as an example for the transformation of oxy-flavo-
purpurine and oxy-anthrapurpurine into the so called cyanines at first quinones
(anthradiquinones) of the cyanines being first produced which are either
spontaneously changed into the cyanines owing to the higher temperature
employed or may be converted into the said cyanines in the well known manner.
VAIDATION
10 parts (the parts are by weight) of dried oxy-flavopurpurine are introduced into
200 parts, of sulphuric acid (66 degrees Baumé) and 15 parts of pulverised
manganese dioxide are added to the resulting mixture. The whole mass is then
heated to about 100 degrees centigrade for three hours or for such a time that a
test portion separated in the known manner yields on dissolving in concentrated
sulphuric acid, a solution which shews a strong cyanine spectrum.
In the mixture obtained the new dye-stuff is partly in the form of cyanine and
partly as an intermediate product which belongs to the series of the quinones or
anthradiquinones described in the Specification of my application for Letters
Patent No. 4871 dated March 18th 1891.

page_text: The mixture is poured into water and an excess of acid sodium sulphite is added.
After boiling the separated dye-stuff is filtered off and washed with water in order
to remove the adherent acid.. The colouring matter thus obtained appears to be
identical with the hexahydroxyanthraquinone described in the Specification of
Letters Patent No. 17712 dated November 4th 1890 and in the Specification of
my application for Letters Patent No. 13667 dated August 13th 1891.
In an analogous manner oxyanthrapurpurine can be converted into the cyanine
dye-stuff which my foreign correspondents have found to be identical with the-
alizarin hexacyanine described in the Specification of my application for Letters
Patent No. 4871 dated March 18th 1891.
When in the preceding example a greater quantity of the oxidising agent viz. :
manganese dioxide (say about 20 parts) and a greater quantity of sulphuric acid
are employed the oxidation commences at from about 25 to 30 degrees centigrade.
In carrying out the reaction on the latter conditions the dye-stuffs are found to be
in the mixture as quinones or anthraquinones.
In the Specification of Letters Patent No. 18729 granted to me and dated.
November 19th 1890 it is stated that oxyflavopurpurine and oxyanthrapurpurine
are produced by a moderate oxidation of flavopurpurine and anthrapurpurine and
my foreign correspondents have now discovered that the production of oxyflavo-
purpurine and oxyanthrapurpurine and the oxidation of the latter two substances
into the cyanines may be done in one operation.
The following may be given as an example for the conversion of anthra-..
purpurine into the dye-stuff belonging to the series of alizarine cyanines, the parts
being by weight.
SECOND EXAMPLE.
OXIDATION OF ANTHRAPURPURINE INTO THE CYANINE DYE-STUFF.
10 parts of dried anthrapurpurine are introduced into 200 parts of concentrated
sulphuric acid (66 degrees Baumé) and after adding 25 parts of manganese
dioxide containing 90 per cent. of pure dioxide the mixture is heated at 120 degrees
centigrade for say five hours. The end of the reaction may be ascertained by the
aid of the spectroscope as mentioned under the first example and the dye-stuff can
be separated as described in that example.
When the anthrapurpurine is replaced by flavopurpurine the reaction proceeds
in an analogous manner.
The oxidation of anthrapurpurine and flavopurpurine into the cyanines can be
carried out at lower temperature, but then a greater quantity of the oxidising
agent and of the sulphuric acid is necessary. The following is an example for the
conversion of anthrapurpurine into the cyanine dye-stuff at a lower temperature
the parts being by weight.
UXIDE.ON OF ANTHRAPURPURINE INTO THE CYANINE DYESTUFF.
10 parts of dry anthrapurpurine are introduced into 500 parts of concentrated
sulphuric acid and 22 parts of pulverised manganese dioxide are added whilst
continually stirring taking care at the same time that the temperature does not rise
above 35 degrees centigrade towards the end of the operation. Thereupon the
whole is poured into water and the quinone of the alizarin hexacyanine separates
in violet flakes. After adding 10 parts of an acid sodium sulphite solution
(35 degrees Baumé) the whole is heated to the boiling point. The conversion of
the anthradiquinone first produced into the alizarine hexacyanine is recognised by
the change in colour of the precipitate from violet to brown. The hexacyanine
filtered off is washed out and purified by redissolving in alkali and subsequently
precipitating with acids

page_text: By further researches my foreign correspondents have found that other trihy-
droxyanthraquinones such as oxychrysazine can likewise be changed by oxidation
into dye-stuffs belonging to the alizarin-cyanine series. The oxidation of oxy-
chrysazine proceeds easily and commences at ordinary temperatures and in the
first place the quinone (anthradiquinone) of the cyanine is formed which is
converted into the alizarin cyanine by boiling with water, heating with acids or
treating with reducing agents such as sulphurous acid or the like.
My foreign correspondents have further discovered that dihydroxyanthra-
quinones which do not possess dyeing properties also can be changed into alizarin
cyanine colouring matters by subjecting them to treatment in sulphuric acid
solution with oxidising agents. The following compounds belonging to the series
of dihydroxyanthraquinones may be employed in the said process: viz. :-anthra-
flavinic acid, isoanthraflavinic acid and authrarufin.
The method for the conversion of the last named dihydroxyanthraquinones into
cyanine dye-stuffs is analogous to that which is hereinbefore described for the
transformation of anthrapurpurine. The end of the reaction is recognised most
practically and distinctly by meaus of the spectroscope.
II.
My foreign correspondents have further found that also several colouring-
matters which contain nitrogen and are derived from alizarin bordeaux and
alizarin cyanines can be converted into new valuable dye-stuffs by an oxidising
process which takes place with great ease and even at ordinary temperature.
So called intermediate products also are at first formed in this process these
intermediate products belonging to the series of anthradiquinones according to
their chemical properties and are converted into the dye-stuffs by boiling them
with water or heating with acids or treating with reducing agents such as for
instance sulphurous acid. The resulting dye-stuffs in general produce with the aid
of mordants shades which are greener than those obtained by means of the said
original substances.
The following substances can be employed in such a process :
1. The products obtained by the action of ammonia on alizarin bordeaux,
alizarin pentacyanine, alizarin hexacyanine, hexahydroxy-anthraquinone, and the
compound resulting from combining salicylic acid with the quinone of alizarin-
pentacyanine which substances are described in the Specification of my application
for Letters Patent No. 8702 dated May 21st 1891.
2. The substances resulting by the action of ammonia and oxygen or atmospheric
air on alizarin pentacyanine, alizarin hexacyanine and hexahydroxyanthraquinone
which compounds are described in the Specification of my application for Letters
Patent No. 4871 dated March 18th 1891.
The following may be given as an example for the formation of new colouring-
matters by subjecting the last named two series of compounds to an oxidation
process (the parts are by weight).
5
OXIDATION OF THE PRODUCT OBTAINED BY THE ACTION OF AMMONIA ON
ALIZARIN BORDEAUX.
10 parts of the dried product resulting by the action of ammonia on alizarin
bordeaux are dissolved in 200 parts of concentrated sulphuric acid (66 degrees
Baumé) at a temperature of from about 20 to 25 degrees centigrade and 12 parts
of pulverised manganese dioxide (containing 90 per cent. of dioxide) are added
O whilst constantly stirring. After the addition of the dioxide the mixture is further
stirred for say 3 hours and is then poured into water. In order to convert into the
dye-stuff the intermediate product which is first produced and separates the liquid

page_text: is mixed with such a quantity of acid sodium sulphite as is necessary for producing
an excess of sulphurous acid and is thereupon, heated to boiling. The precipitate
which separates is filtered off and washed. The dyestuff thus obtained is a dark
paste which dissolves in ammonia liquid with a bluish violet colour in soda lye with
a greenish blue colour, and in concentrated sulphuric acid with a violet colour. By
means of chromium mordants it produces beautiful and pure blue shades which are
much greener than those obtained in the employment of the original material; that
is the product resulting by the action of ammonia on alizarin bordeaux.
In a similar manner the analogous products are obtained when the other
substances of the aforesaid two series are employed.
DYE-STUFF OBTAINED BY THE ACTION OF AMMONIA ON THE INTERMEDIATE
PRODUCT RESULTING AS DESCRIBED IN THE PRECEDING FOURTH EXAMPLE.
10 parts of the product formed by treating alizarin bordeaux with ammonia are
oxidised by means of manganese dioxide in sulphuric acid solution as described in
the preceding fourth example. The mixture, thereupon, is poured into ice water
and the intermediate product which separates is filtered off, washed out with icy
cold water and dissolved in an excess of dilute ammonia liquid. After beating the
resulting solution to boiling the dye-stuff formed is precipitated by the addition of
acids. It differs from the dye-stuff obtained as described in the preceding fourth
example by treating the first formed intermediate product with reducing agents
such as sulphurous acid.
Dated this 27th day of January 1892.
:
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring-matters Derived from
Anthraquinone.
I BENJAMIN WILLCOX of 47, Lincoln's Inn Fields in the County of Middlesex
Patent Agent, do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Farbenfabriken vormals Friedrich
Bayer & Co. of Elberfeld in the. Empire of Germany) and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement :-
In the Specifications of Letters Patent granted to me No. 12715 dated
13th August 1890, No. 17712 dated 4th November 1890 No. 18729 dated
19th November 1890 and No. 4871 dated 18th March 1891 it is stated that by
treating certain tetrahydroxyanthraquinones dissolved in sulphuric acid with
oxidising agents they can be transformed. into new valuable dye-stuffs which dye
blue with the aid of chromium mordants and which have been termed "alizarin
cyanine."
In this manner alizarin bordeaux, purpurin bordeaux and anthrachrysone which

page_text: are tetrahydroxyanthraquinones as well as anthrapurpurine bordeaux and flavo-
purpurin bordeaux which appear also to be tetrahydroxyanthraquinones can by
treatment with oxidising agents in sulphuric acid solution be changed into so called
alizarin cyanines.
My foreign correspondents have now found that other tetrahydroxyanthra-
quinones especially hydroxyflavopurpurin and hydroxyanthra purpurin which are
described in the Specification of Letters Patent No. 18729 granted to me and
dated November 19th 1890 are, by treatment in sulphuric acid solution with
manganese dioxide or arsenic acid or other suitable oxidising agents, converted
into dye-stuffs belonging to the series of the alizarin cyanines.
In order to carry out this process, either a somewhat higher temperature, such
as from about 50 to 150 degrees centigrade, or a greater quantity of the oxidising
agent is necessary; in the latter case the oxidation is carried out at from about
25 to 30 degrees centigrade preferably in presence of a larger quantity of sulphuric
acid (for instance from 30 to 40 parts) than is usually employed in analogous
operations.
•
The following is given as an example of the method of converting hydroxyflavo-
purpurin and hydroxyanthra purpurin into the so-called cyanines, quinones (anthra
diquinones) of the cyanines being first produced which either spontaneously change
into the cyanines owing to the higher temperature employed or may be converted
into the said cyanines in the well known manner. The parts are by weight in all
OXIDATION OF HYDROXYFLAVOPURPURIN.
10 parts of dried oxyflavopurpurin are introduced into 200 parts of sulphuric
acid (66 degrees Baumé) and 15 parts of pulverised manganese dioxide are added
to the resulting mixture at from 60 to 70 degrees centigrade. The whole mass is
then heated to about 100 degrees centigrade for three hours or until a test portion
separated in the known manner when dissolved in concentrated sulphuric acid
yields a solution exhibiting a strong cyanine spectrum.
In the resulting mixture the new dye-stuff is present partly in the form of
cyanine and partly as an intermediate product belonging to the series of the
quinones or anthradiquinones described in the Specification of Letters Patent
No. 4871 dated 18th March 1891.
The mixture is poured into water and an excess of acid sodium sulphite is then
added. After boiling the dye-stuff which separates is filtered off, and washed with
water in order to remove the adherent acid. The colouring matter thus obtained
is identical with the hexahydroxyanthraquinone described in the Specification of
Letters Patent No. 17712 dated November 4th 1890.
In an analogous manner hydroxyanthrapurpurin can be converted into the
cyanine dye-stuff which my foreign correspondents have found to be identical with
the alizarin hexacyanine described in the Specification of Letters Patent No. 4871
dated March 18th 1891.
If in operating according to the preceding example a greater quantity of the
oxidising agent riz. manganese dioxide (say about 20 parts) and a greater quantity
of sulphuric acid be employed, the oxidation can be performed at from about
25 to 30 degrees centigrade on carrying out the process under these latter con-
ditions, the dye-stuffs are found to be present in the mixture as quinones
(anthradiquinones).
In the Specification. of Letters Patent No. 18729 granted to me and dated
November 19th 1890 it is stated that hydroxyflavopurpurin and hydroxyanthra-
purpurin are produced by moderate oxidation of flavopurpurin and anthrapurpurin.
My foreign correspondents have now discovered that the production of hydroxy-
flavopurpurin and hydroxyanthrapurpurin and the oxidation of the latter two
substances into the cyanines may be effected in one operation.

page_text: cyanine colouring matters by subjecting them to treatment in sulphuric acid
solution with oxidising agents. The following compounds belonging to the series
of dihydroxy anthraquinones may be employed in the said process niz.:-anthra-
flavic acid, isoanthraflavic acid and anthrarufin.
•
The method of converting the last named dihydroxy anthraquinones into cyanine
dye-stuffs is analogous to that which is herein before described for the trans-.
formation of anthrapurpurin. The end of the reaction in these processes is also
most practically and distinctly recognised by means of the spectroscope. A
somewhat higher temperature can be employed for transforming the dihydroxy.
anthraquinones than that which is used for the conversion of the analogous tri- or
tetra-hydroxy anthraquinones.
- As a general result my foreign correspondents have found that all dihydroxy,
trihydroxy and tetrahydroxy anthraquinones which contain at least one hydroxylic
group in every benzene nucleus can be oxidised in the manner hereinbefore
described into alizarin cyanine like compounds or so called anthradiquinones which
are-formed as intermediate products and easily yield the cyanine dye-stuffs. They
have ascertained that hydro oxyanthrapurpurin anthrapurpurin and isoanthraflavic
acid are converted by such a treatment into the alizarin hexacyanine described in
the Specification of Letters Patent No. 4871" whilst anthraflavic acid hydroxy
flavopurpurin and flavopurpurin yield the hexhydroxyanthraquinone described in
the Specification of Letters Patent No. 177120 and anthrarufin is changed into the
alizarinpentacyanine described in the Specification of Letters Patent No. 4871"1
hydroxychrysazine yields at first alizarinpentacyanine or the corresponding quinone,
then a mixture of alizarinhexacyanine and hexahydroxyanthraquinone or a mixture
of the corresponding quinones of alizarinḥexacyanine and hexahydroxyanthra-
quinone.
::
My foreign correspondents have further found that several colouring-matters
which contain nitrogen derived from alizarin bordeaux or alizarin cyanines can be
converted into new valuable dye-stuffs by an oxidising process which may be.
effected with great ease and even at ordinary temperature. So-called intermediate
products are also at first formed in this process; these intermediate products which
belong, judging from their chemical properties, to the series of anthradiquinones
are converted into the dye-stuffs by boiling them with water or heating with acids
or treating with reducing agents such as for instance sulphurous acid. The
resulting dye-stuffs in general produce with the aid of mordants greener shades
than those obtained by means of the said original substances.
The substances which can with advantage be employed in such a process are the
two products obtained by the action of ammonia on alizarin bordeaux or alizarin
pentacyanine described in the Specification of Letters Patent No. 8702 dated:
May 21st 1891.
The following is given as an example of the method of producing new colouring
matters by subjecting the last named two products to an oxidation process..
FOURTH EXAMPLE.
OXIDATION OF THE PRODUCT OBTAINED BY THE ACTION OF AMMONIA' ON
ALIZARIN BORDEAUX.
10 parts of the dried product resulting from the action of ammonia on alizarin
bordeaux are dissolved in 200 parts of concentrated sulphuric acid (66 degrees
Baumé) and 12 parts of finely pulverised manganese dioxide (containing 90 per cent.
of dioxide) are added whilst constantly stirring, the temperature being maintained
at. from about 20 to 25 degrees centigrade. After the addition of the dioxide the
mixture is further stirred for say three hours and is then poured into water. In
order to convert the intermediate product which is first produced and separates as
a blackpipate. insoluble in water, into the dyestuff the liquid is mixed with
such a quantity of acid sodium sulphite (for instance 10 parts of an. acid. sodium

page_text: sulphite solution, 34 degrees Baumé) as is necessary for producing an excess of
sulphurous acid and is thereupon heated to boiling. The conversion of the inter-
mediate product into the dye-stuff is recognized to have taken place by the change
of its colour into brownish-violet.
The precipitate which remains undissolved is filtered off and washed. The dye-
stuff thus obtained is a dark paste which dissolves in sodium carbonate and caustic
ammonia with a violet colour, in soda-lye with an indigo-blue colour and in con-
centrated sulphuric acid with a violet-red colour. It is dissolved by alcohol with
a bluish-red colour and the resulting solution, unlike that of the original product
exhibits a characteristic and distinct absorption spectrum. It affords beautiful
and pure blue shades with chromium mordants.
The oxidation of the product obtained by the action of ammonia on alizarin-
pentacyanine is effected in a similar manner.
My foreign correspondents do not limit themselves to the proportions given in the
preceding fourth example for the production of dye-stuffs by oxidising products.
resulting from the action of ammonia on alizarin bordeaux or alizarin pentacyanine.
The method of producing these colouring matters can be varied in a number of
ways without departing from the nature of this invention.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. Production of so called anthradiquinone compounds, which are quinones of
alizarincyanines, by treating anthraflavic acid, isoanthraflavic acid, anthrarufin,
hydroxychrysazin, flavopurpurin, anthrapurpurin, hydroxyflavopurpurin, hydroxy-
anthrapurpurin dissolved in sulphuric acid with manganese dioxide or other
oxidising agents at temperatures of from about 0 to 60 degrees centigrade.
2. Conversion of the anthradiquinone compounds produced by means of the
method claimed by the preceding first claim, or by any other method. producing
the same result, into the corresponding alizarincyanine dye-stuff by heating them
with water or acids or by treating with reducing agents.
'
3. Process for producing the alizarincyanine colouring matters defined in the
preceding second claim by heating anthraflavic acid, isoanthraflavic acid,
anthrarufin, hydroxychrysazin, flavopurpurin, anthrapurpurin, hydroxyflavo-
purpurin, hydroxyanthrapurpurin dissolved in sulphuric acid with manganese
dioxide or other oxidising agents at elevated temperatures.
4. Manufacture of so called intermediate products, belonging to the series of
anthradiquinones, by treating with manganese dioxide or other oxidising agents at
temperatures not rising above 40 degrees centigrade solutions in sulphuric acid of
the following substances described in the Specification of Letters Patent
No. 87021 viz. the products resulting from the action of ammonia on 'alizarin
bordeaux and alizarin pentacyanine.
5. Conversion of the intermediate products defined in the preceding 4th Claim,
into the corresponding new alizarincyanine dye-stuffs by heating them with water
or acids or by heating with reducing agents.
6. Production of new alizarincyanine dye-stuffs by treating with manganese
dioxide or other oxidising agents at elevated temperatures, solutions in sulphuric
acid of the products resulting from the action of ammonia on alizarin bordeaux and
alizarin pentacyanine and subsequently heating the so formed anthradiquinone-like
intermediate products with water or acids or by treating these intermediate products
with reducing agents.
7. As new manufactures the following compounds :
a.) So-called intermediate products belonging to the series of anthradi-
quinones which can be obtained by treating with oxidising agents solutions
in sulphuric acid of the products described in the Specification of Letters
Patent N 87000 and mosulting from the nation of Ammania
An
alizarin

page_text: b.) Dye-stuffs belonging to the series of alizarincyanines which can be
produced by heating the intermediate products defined in this 7th claim
(under the preceding part a thereof) with water or diluted acids or by
treating these intermediate products with reducing agents.
Dated this 27th day of October 1892.