AN IMPROVED MANUFACTURE OF SULPHO-ACID OR ITS SALTS FROM GREEN COLOURING MATTER OR ITS BASE
Year: 1879

page_text: LETTERS PATENT to Henry Harris Lake, of the Office of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"AN IMPROVED MANUFACTURE OF SULPHO-ACID OR ITS SALTS FROM GREEN
COLOURING MATTER OR ITS BASE." A communication from abroad by
Messrs. Bindschedler and Busch, of Basle, Switzerland.
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 23rd June 1879.
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED MANUFACTURE OF SULPHO-ACID
OR ITS SALTS FROM GREEN COLOURING MATTER OR ITS BASE." [A communication
from abroad by Messieurs Bindschedler and Busch, of Basle, Switzerland.]
This Invention consists in the transformation into sulpho-acid or its salts of the
differently shaded now fast green colouring matters manufactured by variously
conducted oxidation of the tetramethyldiamidotriphenylmethan.
The green colouring matter thus obtained is very advantageously applicable to
dyeing and printing. The production of the sulpho-acid is effected as follows, that
is to say:-One hundred parts of the base of the said new fast green, or the equi-
valent quantity of new fast green, are dissolved in one hundred parts of English
sulphuric acid; then one hundred and sixty parts of fuming sulphuric acid con-
taining forty five per cent. of anhydrous sulphuric acid are added, and the whole
heated until a sample taken out dissolves in boiling alkaline water. According to
the temperature and the length of time during which the operation is subjected to
the above process, sulpho-acids of a more or less easy solubility in water are produced.
These sulpho-acids also differ from each other in shade and tinctorial power; the
difficultly soluble sulpho-acid is considered preferable to any other. A four hours'
heating on the waterbath is quite sufficient to produce a complete transformation
into sulpho-acid. The solution is then poured into water, and after the neutralization
of the undecomposed sulphuric acid by means of caustic soda the sulpho-acid of
the new fast green is precipitated. If the concentrated solution is completely
neutralized with caustic soda it is the soda salt of the sulpho-acid of the new fast
green that precipitates.
The free sulpho-acid or the soda salts of the sulpho-acid are brought into the
market in form of paste or as dry powder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Harris Lake in the Great Seal Patent Office on the
22nd December 1879.
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED MANUFACTURE OF SULPHO-ACID
OR ITS SALTS FROM GREEN COLOURING MATTER OR ITS BASE." A communication
from abroad by Messrs. Bindschedler and Busch, of Basle, Switzerland.
This Invention consists in the transformation of the "new fast green
base into sulpho acid or its salts.
"3
or its
The green coloring matter thus obtained is very advantageously applicable for
dyeing and printing purposes.
The denomination of "new fast green" is applied to the differently shaded green
coloring matters manufactured by my foreign correspondents by variously conducted
processes of oxidation of the tetramethyldiamidotriphenylmethan, the discovery of
which is due to Messieurs Emile and Otto Fischer, of the well known firm of that
name.
In the production of sulpho acid one hundred parts of the base of new fast green,
or the equivalent quantity of new fast green, are dissolved in one hundred parts of
English sulphuric acid; then one hundred and sixty parts of fuming sulphuric acid
containing forty five per cent. of anhydrous sulphuric acid are added, and the whole
heated until a sample taken out dissolves in boiling alkaline water.
According to the temperature and the length of time during which the above
process is continued, sulpho-acids of a more or less casy solubility in water are
produced. These sulpho-acids also differ from each other in shade and tinctorial
power.
The sulpho-acid which is not readily soluble is apparently preferable to any
other.
A four hours' heating in the water bath is quite sufficient to produco a complete
transformation into sulpho-acid.
The solution is then poured into water, and after the neutralization of the unde-
composed sulphuric acid by means of caustic soda the sulpho-acid of the
new fast
green " is precipitated. If the concentrated solution is completely neutralized with
caustic soda, it is the soda salt of the sulpho-acid of the "new fast green" that
precipitates.
The free sulpho-acid, or the soda salts of the sulpho-acid are brought into the
market in the form of paste or dry powder.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it to be
understood that I claim,-
The transformation of the "new fast green" or its base into sulpho-acid or its
salts.
In witness whereof, I, the said Henry Harris Lake, have hereunto set my
hand and seal, this Twenty second day of December, in the year of our
HENRY H. LAKE. (L.S.)