Manufacture of a New Leuko Compound of the Gallocyanine Group.
Year: 1895

page_text: Date of Application, 30th Aug., 1895-Accepted, 26th Oct., 1895
COMPLETE SPECIFICATION.
[Communicated from abroad by JEAN CLAUDE LOUIS DURAND, DANIEL
EDOUARD HUGUENIN, and ADOLPHE JEAN JAMES D'ANDIRAN, con-
stituting the Firm of L. Durand, Huguenin & Co., of Basle, Switzerland,
Manufacturers.]
Manufacture of a New Leuko Compound of the Gallocyanine Group.
I, CHARLES DENTON ABEL, of 28 Southampton Buildings, Chancery Lane,
in the County of London, Consulting Engineer and Chartered Patent Agent,
do hereby declare the nature of this invention and in what
same is to be performed to be particularly described and ascertained in and by
the following statement :-
manner the
In the Specification to Patent No. 15064 of 1894 was described the manufacture
of a leuko compound of the gallocyanine group suitable for printing purposes,
which was produced by the condensation of resorcine with gallamine blue.
My correspondents have now discovered that by the condensation of resorcine
with the gallocyanine colouring matter which is produced by the combination of
gallamic acid with hydrochlorate of nitrosodiethylaniline, or hydrochlorate of
diethylamidoazobenzol, a similar leuko compound suitable for printing on fabrics,
is obtained, but which is mainly distinguished from the one produced from
gallamine blue in that it is very easily soluble both in hot and in cold pure water
and when oxidised upon the fibre, gives much bluer tints than the corresponding
leuko compounds from gallamine blue.
The production of the new leuko body is effected as follows:
300 kilos. of the gallocyanine colouring matter obtained by the action of
gallamic acid upon hydrochlorate of diethylamidoazo-benzol or hydrochlorate
of nitrosodiethylanilin, are heated on the water bath together with 150 kilos.
of resorcine, 200 litres of water and 900 kilos. of ordinary hydrochloric acid until
the blue colouration has completely disappeared.
The reaction-product obtained by filtration is pressed and dissolved in pure
water.
The solution obtained is boiled and the leuko body is precipitated by means
of salt or an acid. The new leuko body thus obtained, which is almost insoluble
in acidulated water, in alcohol, as also in a solution of acetate of soda, is readily
soluble in pure cold and warm water. In a 10 p.c. carbonate of soda solution, as
also in soda lye, it dissolves with a yellowishgreen colouration which passes rapidly
over into blue. In hot glacial acetic acid the new leuko body is tolerably
soluble. Its solution in concentrated sulphuric acid is of a yellowish-brown colour,
and, on the addition of minute quantities of nitric acid it becomes first blue and
then red.
If the new leuko compound is printed with a chrome mordant upon cotton or
other fabrics, and is oxidized on the fibre, it is converted into a blue colouring
matter. In consequence of its easy solubility in water, it can also be used for
dyeing, for which purpose it is oxidized on the fibre by means of an oxidizing
agent, such as sodium chlorate, which is added to the dye bath.
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 Process for the manufacture of a leuko compound, suitable for printing and

page_text: dyeing, by the condensation of resorcine with the gallocyanine colouring matter
which is produced by the action of gallamic acid upon hydrochlorate of
diethylamidoazobenzol, or hydrochlorate of nitrosodiethylaniline, substantially as
described.
2. As a new manufacture the leuko compound produced as herein described.
Dated this 30th day of August 1895.
ABEL & IMRAY,
Agents for the Applicant.