Year: 1886

page_text: Date of Application, 12th May, 1886.
Complete Left, 12th Feb., 1887.
Complete Accepted, 15th Mar., 1887.
[Communicated from abroad by THE BADISCHE ANILINE AND SODA FABRIK, at
Ludwigshafen on the Rhine, in the Empire of Germany.]
This invention relates to the production from gallic acid of a new yellow colouring
matter capable of being employed in Dyeing and Printing in a similar manner to that
in which artificial Alizarine is employed.
The said colouring matter which I will hereinafter term Galloflavine is an inter-
mediate product of the oxydizing action of atmospheric air or oxygen upon alkaline
solutions of gallic acid.
The production of Galloflavine in appreciable quantity depends upon certain
conditions hereinafter defined, the influence of which upon the nature of the oxydation
products of Gallic acid has not hitherto as far as I am aware been made the subject
matter of research.
Now this Invention is based upon the following observations.
Solutions of gallic acid in which the hydrogen atoms of its hydroxyle-groups are
completely substituted by the alkali-metals, or which contain an excess of caustic soda
or potash, rapidly absorb oxygen from the air and consequently assume, as is well
known, an intense yellowish brown colour.
No appreciable amount of Galloflavine is however formed under the said conditions.
But if alkaline solutions of gallic acid be prepared with the alkaline carbonates or
with relative proportions of caustic soda or potash not sufficient to saturate the three
hydroxyle-groups of gallic acid such solutions upon the admittance of air quickly
assume an olive or brownish green colour, and during the progress of the oxydizing
action thus taking place Galloflavine will be gradually produced and finally destroyed
again, unless the action be discontinued at the proper time.

page_text: The
In order to obtain a satisfactory yield of the new coloring matter it has been found
advantageons to employ say two or three molecules of caustic alkali (by preference of
caustic potash) for every molecule of the gallic acid to be operated upon.
alkaline carbonates have so far produced inferior results. The oxydation ought to be
retarded by the application of a low temperature and not allowed to proceed beyond
the point in which the maximum of Galloflavine has been formed. This point will be
most safely and conveniently arrived at by using the test hereinafter described.
It is likewise advisable, from time to time or in a continuous manner, to precipitate
and thus to withdraw the colouring matter from its alkaline solution, in order to
prevent the destructive effect of excessive oxydation.
For the said purpose it has so far been found practical to oxydise gallic acid in a
dilute alcoholic solution, from which the potassium-salt of Galloflavine, on account of
its being but sparingly soluble therein, separates out almost as fast as it forms.
The following description is intended to illustrate, by way of an example, the
method of producing Galloflavine.
About five parts by weight of gallic acid are dissolved in about eighty parts by
weight of strong alcohol or methylated spirit and about one hundred parts of water.
The solution thus obtained is cooled down to a temperature ranging between five and
ten degrees Centigrade, and under constant agitation about seventeen parts by weight
of caustic potash liquor of about 1.26 specific gravity are gradually added.
The alkaline solution is then exposed to the action of atmospheric air at a
temperature not exceeding ten degrees Centigrade. For this purpose a strong
current of air may be passed through the alkaline solution or properly constructed
apparatus may be employed, whereby the surface of the solution is continuously
renewed and fresh portions of the same are gradually exposed to the access of air.
The progress of the oxydation will soon be rendered apparent by the before
mentioned olive or brownish-green colour of the solution gradually increasing in
intensity, and after some time a crystalline precipitate-the potassium salt of the new
colouring matter-will begin to settle out.
In order to ascertain the point in which the production of Galloflavine has reached
its maximum the following test is to be applied. From time to time, a sample is to be
withdrawn and filtered. The filtered liquor is then to be shaken up with air and
examined after some time to see if it contains a precipitate, which refuses to dissolve
in dilute hydrochloric acid.
If the said precipitate be not produced, the operation ought to be at once discontinued
in order to prevent the destructive effect of the before-mentioned excessive oxydation.
The crystalline pulp is then quickly filtered, pressed and dissolved in warm water of
about 50 degrees Centigrade. The aqueous solution is acidulated with a slight excess
of hydrochloric or sulphuric acid and afterwards boiled until the flocculent precipitate
of the colouring matter has assumed a crystalline appearance.
The colouring matter thus obtained is filtered, washed with tepid water, and it
may then be dried or by preference be left in the state of a paste suitable for Dyeing
and Printing.
Galloflavine combines with metallic oxydes thus forming yellow lakes or pigment.
colours varying in shade from a greenish to an orange-yellow. It can be fixed upon
textile fibres by means of Alumina, Chrome, Tin or like mordaunts in a manner
similar to that in which artificial Alizarine is fixed. The chrome-lake fixed upon
cotton or linen is particularly distinguished by its resistance to the action of soap,
light and air.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.

page_text: The Preparation from Gallic Acid of a Yellow Colouring Matter
Suitable for Dyeing and Printing.
I JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention which has been communicated
to me from abroad by The Badische Aniline and Soda Fabrik of Ludwigshafen on
the Rhine 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:
This Invention relates to the production from gallic acid of a new yellow colouring
matter capable of being employed in Dyeing and Printing.
The said colouring matter which hereinafter shall be termed "Galloflavine" is an
intermediate product of the oxydizing action of atmospheric air or of oxygen upon
alkaline solutions of gallic acid.
The production of "Galloflavine" in appreciable quantity depends upon certain
conditions hereinafter defined the influence of which upon the nature of the oxydation
products of gallic acid has not hitherto as far as I am aware been made the subject
matter of research.
Now this Invention is based upon the following observations:-
Solutions of gallic acid in which the hydrogen atoms of its three hydroxyle groups
are completely substituted by the alkali metals (or in other words, solutions of alkaline
gallates containing an excess of caustic soda or potash) rapidly absorb oxygen from
the air and consequently assume, as is well known, an intense yellowish-brown colour.
No appreciable amount of
Galloflavine is however formed under the said
conditions.
But if alkaline solutions of gallic acid be prepared with the employment of alkaline
carbonates, or with relative proportions of caustic soda or potash not sufficient to
saturate the three hydroxyle groups of gallic acid, such solutions upon the admittance
of atmospheric air or oxygen gas quickly assume an olive or brownish green colour,
and during the progress of the oxydizing action, thus taking place, "Galloflavine"
will be gradually produced and finally destroyed again, unless the action be discontinued
at the proper time.
In order to obtain a satisfactory yield of the new colouring matter it has been found
advantageous to employ say two or three molecules of caustic alkali (by preference of
caustic potash) for every molecule of the gallic acid to be operated upon. The
oxydation ought to be retarded by the application of a low temperature, and not to be
allowed to proceed beyond the point in which the maximum of "Galloflavine" has
been formed. This point will be inost safely and conveniently arrived at by using the
test hereinafter described.
In order to prevent the destructive effect of excessive oxydation the operation ought
not only to be stopped at the proper point, as before said, but it is moreover advisable
either from time to time or, by preference, in a continuous manner, to precipitate and
thus to withdraw the already-formed portions of the colouring matter from their
alkaline solution. For this purpose the oxydation of Gallic acid is most conveniently
performed by employing dilute alcohol as a solvent, in as much as the alkaline salts of
" Galloflavine" (and especially the potassium salt) on account of their being but
sparingly soluble in the said solvent will separate out almost as fast as they form.

page_text: In practice it has not been found advantageous to employ the carbonates of potash
or soda in lieu of the corresponding caustic alkalies on account of the inferior yield of
colouring matter thus produced.
The following description is intended to illustrate, by way of an example of the
manner in which the Invention may be performed a method by which "Galloflavine "
may be produced according to the said Invention.
About five parts by weight of gallic acid are dissolved in about eighty parts by
weight of strong alcohol or methylated spirits and about one hundred parts of water.
The solution thus obtained is cooled down to a temperature ranging between five and
ten degrees Centigrade, and under constant agitation about seventeen parts by weight
of caustic potash liquor of about 1.26 specific gravity are gradually added.
The alkaline solution is then exposed to the action of oxygen which may be effected
by exposure to atmospheric air at a temperature of about zero of Centigrade and not
exceeding ten degrees Centigrade.
This operation may be carried out in various ways and with the application of
various mechanical contrivances employed for analogous operations in which the
direct oxydizing action of oxygen or atmospheric air is made use of for manufacturing
purposes. For instance a strong current of atmospheric air may be blown or drawn
through the alkaline solution, or apparatus or agitators may be employed which will
cause the surface of the solution to be continuously removed, and fresh portions of the
same to be gradually exposed to the oxygen or atmospheric air. The progress of the
oxydation will soon be rendered apparent by the olive or brownish green colour of
the solution gradually increasing in intensity and after some time a crystalline
precipitate the potassium salt of the new colouring matter-will begin to settle out.
In order to ascertain the point at which the production of "Galloflavine" has
reached its maximum the following test is to be applied.
From time to time a sample of the liquor under treatment is to be withdrawn and
filtered. The filtered liquor is then to be shaken up with air and examined, after
some time to see if it contains a precipitate, which will not dissolve in dilute
hydrochloric acid. If the said precipitate be not produced, the operation ought to be
at once discontinued, in order to prevent as above said the destructive effect of
excessive oxydation. The crystalline pulp is then quickly filtered, pressed, and
dissolved in warm water of about (500) fifty degrees Centigrade. The aqueous
solution is acidulated with a slight excess of hydrochloric or sulphuric acid, and
afterwards hoiled, until the flocculent precipitate of the colouring matter has assumed
a crystalline appearance. The colouring matter thus obtained is filtered, washed with
tepid water, and it may then be dried or by preference, be left in the state of a paste
suitable for dyeing and printing.
22'
"Galloflavine combines with metallic oxides thus forming yellow lakes or pigment-
colours, varying in shade from a greenish yellow to an orange-yellow. It can be fixed
upon textile fibres by means of Alumina, Chrome, Tin, or like mordants in a manner
similar to that in which artificial Alizarine is fixed. The chrome-lake, fixed upon
cotton or linen, is particularly distinguished by its resistance to the action of soap,
light, and air.
"
Having now particularly described and ascertained the nature of the said Invention
and in what manner the same is to be performed I declare that what I claim is
The preparation of the herein before described Galloflavine," by the oxydizing
action of atmospheric air or oxygen gas upon alkaline solutions of gallic acid
(preferably with the employment of dilute alcohol as a solvent) substantially as
hereinbefore described.
J. HENKY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agents.