IMPROVEMENTS IN PREPARING COLORING MATTERS SUITABLE FOR DYEING AND PRINTING
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents on the 5th September 1881. A com-
munication from abroad by the Badische Anilin and Soda Fabrick, of
Ludwigshafen on the Rhine, in the Empire of Germany.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PREPARING COLORING MATTERS SUITABLE FOR
DYEING AND PRINTING." A communication from abroad by the Badische Anilin
and Soda Fabrik, of Ludwigshafen on the Rhine, in the Empire of Germany.
This Invention relates to the conversion of the well known, and in water almost
insoluble, coeruleïne into a new soluble compound of the said coloring matter by
means of and together with the bisulphites of the alkalies. This new compound is
hereinafter designated "coeruleïne S."
In carrying out this Invention coeruleïne in the form of paste, such as that in
which it is brought into trade, is well mixed with a solution of the bisulphite of
sodium (or of potassium or of ammonium), and such mixture is allowed to stand in
closed vessels during from about 8 to 10 days, whereby it is converted into a thick
yellow greenish product in the form of paste, which is soluble in water.
In order to obtain the product thus resulting in a dry state or condition it is
first pressed, and the residual product is then subjected to the action of heat at a
low temperature.
The substance thus prepared will be a dark greenish powder soluble in water,
and of a yellow-greenish color. Its aqueous solution is decomposed by boiling
when continued for some time, and coeruleïne is precipitated. A similar
decomposition takes place more rapidly by heating the same in the presence of
diluted mineral acids, but no precipitate is formed if to aqueous solutions of the
coeruleïne-bisulphite-compound acetate of chromium is added.
This remarkable property allows the mixed solutions of coeruleïne S and of the
before mentioned metallic salt to be brought on the textile fibre, and by steaming
a fast green coloring matter is produced and fixed in and upon the fibre or fibres.
As an example of the manner in which the compound designated as "coeruleïne S,"
and herein before described is prepared, it is proposed to proceed as follows:-
About 100 lbs. of coeruleïne in the form of a paste, as hereinbefore described (and
which paste may contain about 15 per cent. of dry residue), such as is brought into

page_text: trade, are mixed with about 100 lbs. of the bisulphite of sodium, which is employed
as a solution of 30 degrees Beaumé (1.25 specific gravity).
The mixture is then left to itself during from about 8 to 14 days, after which
time the coeruleïne will be found to have been converted into a yellow-greenish thick
product or paste. The product thus resulting may be employed either directly, or
the coeruleïne compound may be separated from the mother-liquor which contains
only small quantities of the coloring matter dissolved therein either by filtration,
pressure, or otherwise.
The coeruleïne compound thus obtained or resulting may be desiccated or dried
at a low temperature. Although I have mentioned the use of acetate of chromium,
other compounds of that metal may be employed.