The Manufacture or Production of Blue Anthraquinone Dye-stuffs.
Year: 1899

page_text: Date of Application, 12th Apr., 1899
Complete Specification Left 11th Jan 1900 Accepted 17th Feb. 1900
Date of Application, 12th Apr., 1899
Complete Specification Left 11th Jan 1900-Accepted 17th Feb. 1900
[Communicated from abroad by THE FARBENFABRIKEN vormals FRIEDRICH
BAYER & Co., of Elberfeld, Germany.]
The Manufacture or Production of Blue Anthraquinone Dye-stuffs.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
In the Specification of Letters Patent No. 120117 my foreign correspondents
described the production of diamido anthrarufine disulphonic acid and diamido-
chrysazine disulphonic acid (which acids are valuable blue dye-stuffs), by treating
the corresponding dinitro compounds with reducing agents.
My foreign correspondents have now found that instead of chemical reducing
agents, the electric current can also be employed, in order to transform the
dinitro-anthrarufine disulphonic acid, and the dinitro-chrysazine disulphonic
acid, into the above mentioned dye-stuffs.
In order to illustrate this method of proceeding, the following example is
given (the parts being by weight).
EXAMPLE.
A solution prepared from 15 parts of the sodium salt of dinitro-anthrarufine
disulphonic acid, and 300 parts of dilute sulphuric acid, is subjected, at about
90 degrees Centigrade, to the action of an electric current having a density of
300 ampères on each square metre, the anode and the cathode being separated
by a suitable diaphragm. The anodes, which may consist of platinum or of
carbon, are immersed in dilute sulphuric acid; whilst the cathodes, which may
consist of lead, are immersed in the above described solution of the nitro-sul-
phuric acid, which solution is preferably stirred during the reaction.
After a short time, the color of this solution changes into blue, and the color-
ing matter begins to separate in the shape of needles exhibiting a bronze-like
lustre. When the solution is nearly colorless, and the development of hydrogen
begins to increase, the electric current is stopped, and the dye-stuff is separated
from the solution by filtration. The coloring matter thus obtained is identical
with the diamido-anthrarufine disulphonic acid described in the above mentioned
Letters Patent.
If, instead of the dinitro-anthrarufine disulphonic acid, the dinitro-chrysazine
disulphonic acid is employed, the process proceeds in an analogous manner,
diamido-chrysazine disulphonic acid being produced.
My foreign correspondents do not intend to confine themselves to the particu-
lars given in the above example, as these can be varied within wide limits
without affecting the results.
Dated this 12th day of April 1899.

page_text: The Manufacture or Production of Blue Anthraquinone Dye-stuffs.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
In the Specification to Letters Patent No. 120117, my foreign correspondents
have described the production of diamido-anthrarufine disulphonic acid and
diamido-chrysazine disulphonic acid (which acids are valuable blue dye-stuffs),
by treating the corresponding dinitro compounds with reducing agents.
My foreign correspondents have now found that, instead of chemical reducing
agents, the electric current can also be employed in order to transform the
dinitro-anthrarufine disulphonic acid and the dinitro-chrysazine disulphonic
acid into the above mentioned dye-stuffs.
In order to illustrate this method of proceeding, the following example is
given (the parts being by weight).
EXAMPLE.
A solution prepared from 15 parts of the sodium salt of dinitro-anthrarufine
disulphonic acid and 300 parts of dilute sulphuric acid, is subjected, at about
90 degrees Centigrade, to the action of an electric current having a density of
300 ampères on each square metre, the anode and the cathode being separated
by a suitable diaphragm. The anodes, which may consist of platinum or of
carbon, are immersed in dilute sulphuric acid, whilst the cathodes, which may
consist of lead, are immersed in the above described solution of the nitro-sul-
phonic acid, which solution is preferably stirred during the reaction.
After a short time, the color of this solution changes into blue, and the color-
ing matter begins to separate in the shape of needles exhibiting a bronze-like
lustre. When the solution is nearly colorless and the development of hydrogen
begins to increase, the electric current is stopped, and the dye-stuff is separated
from the solution by filtration. The coloring matter thus obtained is identical
with the diamido-anthrarufine disulphonic acid described in the above mentioned
Letters Patent.
If, instead of the dinitro-anthrarufine disulphonic acid, the dinitro-chrysazine
disulphonic acid is employed, the process proceeds in an analogous manner,
diamido-chrysazine disulphonic acid being produced.
My foreign correspondents do not intend to confine themselves to the particu-
lars given in the above example, as these can be varied within wide limits,
without affecting the results.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed (as communicated to me
from abroad), I declare that what I claim is:-
The process for the production of diamido-anthrarufine disulphonic acid and
amido-chrysazine disulphonic acid, which process consists in subjecting dinitro-
anthrarufine disulphonic acid and dinitro-chrysazine disulphonic acid to the
electric current, substantially as hereinbefore described.
Dated this 10th day of January 1900.
NEWTON & SON,
Agents for the Applicant.