Year: 1886

page_text: Date of Application, 9th July, 1886.
Complete Left, 5th Apr., 1887.
Complete Accepted, 6th May, 1887.
[Communicated from abroad by THE FARBWERKE VORMALS MEISTER LUCIUS AND
PRUNING, of Hoechst-am-Main, in the Empire of Germany, a Company carrying
on business as Chemical Manufacturers.]
I, CHARLES DENTON ABEL of No. 28 Southampton Buildings, Chancery Lane in
the County of Middlesex, Consulting Engineer and Patent Agent do hereby declare
the nature of this invention to be as follows:-
:-
This invention relates to the production of green coloring matters or dye stuffs by
the action of nitrous acid upon an acid solution of the coloring-matters known in
commerce as Methylene Blue" and "Ethylene Blue."
"
The following is an example of the way in which the invention may be carried out.
10 parts of methylene-blue are dissolved in 1000 parts of water and the solution
rendered acid by the addition of 100 parts of sulphuric acid. To the cold acid
solution of the methylene-blue are added, by degrees, 8 parts of nitrite of sodium.
The conversion of the methylene-blue into the green coloring-matters proceeds but
slowly and will not be completed before several days. As soon as the solution has
assumed a pure green colour, the coloring matter is precipitated by means of common
salt, filtered and purified by repeated dissolving. The mother-lye contains a compound
which is precipitated by means of zinc-chloride and by careful reduction is
retransformed into methylene-blue.
The reaction may be accelerated by heating, but this will be found rather
disadvantageous as the yield of green coloring matter is lessened thereby.
The reaction will also be completed more promptly when nitric acid is added.
ABEL & IMRAY,
28, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Production of Green Coloring Matters
or Dye Stuffs.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane in
the County of Middlesex, Consulting Engineer and 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 :-
"
This invention relates to the production of green coloring matters or dyestuffs by
the action of nitrous acid upon an acid solution of the coloring matters known in
commerce as Methylene Blue" and "Ethylene Blue" or other alkylised thionin
salts as, for example, the chlorhydrate of trimethyl-thionin or the chlorzine double
salt of the same.
The following is an example of the way in which the invention may be carried out.
10 parts of methylene-blue are dissolved in 1000 parts of water and the solution
rendered acid by the addition of 100 parts of sulphuric acid. To the cold acid
solution of the methylene blue are added, by degrees, 8 parts of nitrite of sodium.
The conversion of the methylene-blue into the green coloring-matters proceeds but
slowly and will not be completed before several days. As soon as the solution has
assumed a pure green color, the coloring matter is precipitated by means of common
salt, filtered and purified by repeated dissolving. The mother-lye contains a
compound which is precipitated by means of zinc-chloride and by careful reduction is
retransformed into methylene-blue.
The reaction may be accelerated by heating, but this will be found rather
disadvantageous as the yield of green coloring matter is lessened thereby. The
reaction will also be completed more promptly when nitric acid is added.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is
66
"
--
The production of green coloring matters or dyestuffs by adding a solution of
nitrite of sodium, with or without some nitric acid, to an acid solution of the coloring
matters known as Methylene Blue" and "Ethylene Blue or of other alkylised
thionin salts, and precipitating the green coloring matter formed, by means of
common salt.
Total thin 5th day of Al 1007