The Manufacture or Production of Colouring Matters.
Year: 1894

page_text: Date of Application, 13th Feb., 1894
Complete Specification Left, 10th Nov., 1894-Accepted, 15th Dec., 1894
[Communicated from abroad by The Farbenfabriken, vormals FRIEDRICH
BAYER & Co., of Elberfeld, in the Empire of Germany.]
The Manufacture or Production of Colouring Matters.
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:-
:-
My foreign correspondents have discovered some time since, a process for
converting dinitroanthraquinone, or the like, into dje-stuffs, by heating with
concentrated sulphuric acid in the presence of boric acid.
The researches of my foreign correspondents have now shown, that in the
production of colouring matters from dinitronaphthalene (a, us), boric acid exerts
a very favourable influence, that is, when the said dinitro-naphthalene is heated
with concentrated sulphuric acid in the presence of boric acid, or agents acting
in a similar manner.
According to the researches of my foreign correspondents, dinitronaphthalene,
when heated with concentrated sulphuric acid in the presence of boric acid, does
not yield, as chief product, naphthazarine (which it is known results as chief.
product when the process is carried out without the addition of boric acid), but a
series of colouring matters is formed which are entirely different from
naphthazarine.
My foreign correspondents have hitherto succeeded in isolating from the reaction
mixture, in particular two dye-stuffs, hereinafter termed "dye stuff A" and " "dye
stuff B," which could easily be separated one from the other by reason of their
different degrees of solubility in dilute sulphuric acid.
The production of these two dye-stuffs is illustrated by the following example,
the parts being by weight.
EXAMPLE.
10 parts of a1 a 3 dinitro naphthalene and 15 parts of crystallized boric acid are
mixed with 250 parts of sulphuric acid (66 degrees Baumé). The resulting mixture
is heated at from 200 to 220 degrees Centigrade. A non-violent reaction takes
place, the sulphuric acid solution assuming a reddish color, and gas being
disengaged. The mass is allowed to cool as soon as the liquid has assumed a deep
bluish red color, and is then poured into 1000 parts of water. After heating to
boiling, the liquid is filtered whilst hot. Small proportions of dinitronaphthalene,
unaltered, and a coloring matter soluble in soda lye, producing a dull violet-red
colored solution, remain on the filter. The aforesaid "dye stuff A " separates as a
black violet precipitate from the hot filtrate, when cooling, and is filtered off. On
adding common salt to the filtrate, the "dye stuff B" is precipitated, which is
likewise isolated by filtration.
My foreign correspondents have also found that in a similar manner as in the
production of naphthazarine, intermediate products are likewise formed in the
process illustrated by the above example, and that these intermediate products can
be converted into the corresponding dye-stuffs by boiling with dilute acids.
The above named dye-stuffs A and B possess the following properties
The dve stuff & " is coluble with diffiante in cold water but more easily in

page_text: a violet-red color, whilst the solution in soda lye possesses a violet color. It
dissolves in concentrated sulphuric acid, yielding a currant-red colored solution.
It produces on wool mordanted with chromium salts, from violet to deep black
shades possessing a reddish hue.
The dye stuff B" dissolves with difficulty in cold pure water; more easily in
cold dilute sulphuric acid; and very readily in hot pure water, producing a
magenta-red coloured solution. It is dissolved with ease by glacial acetic acid,
affording a cherry-red solution, and likewise with ease by concentrated sulphuric
acid, forming a yellowish-red coloured solution. Its solution in ammonia is
carmine-red, whilst its solution in soda-lye has a magenta-red colour. The shades
produced therewith on chromated wool are similar to those obtained by means of
the above "dye stuff A," but possess a considerably bluer hue than those of the
latter colouring matter.
The two dye-stuffs differ from the naphthazarine in a very distinct manner with
reference to the colours resulting on dissolving them in soda lye, for the
naphthazarine, when dissolved in soda ye, yields a beautiful blue coloured
solution.
In order to produce the above or similar mordant-dyeing colouring matters
from α 1 az dinitro naphthalene, my foreign correspondents do not limit themselves
to the directions given in the aforesaid example, as the operations can be varied.
For instance, the boric acid used can be generally replaced by such boron
compounds as yield boric acid when in the presence of sulphuric acid; stronger or
weaker sulphuric acid can be used in place of the sulphuric acid at 66 degrees
Baumé in the latter case applying relatively a lower or higher temperature, or
heating for a longer or shorter period. Such or similar modifications do not alter
the nature of this invention, as it in general relates to the production of dye-stuff's
by heating a, a, dinitro naphthalene with sulphuric acid in the presence of boric
acid or other agents acting in a similar manner.
Dated this 13th day of February 1894.
NEWTON & SON,
Agents for the Applicant.
The Manufacture or Production of Colouring Matters.
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 :—
My foreign correspondents have described in the Specification of Letters Patent
No. 14345, dated 25th July 1893, a process for converting dinitro anthraquinone,
or the like, into dye-stuffs, by heating with concentrated sulphuric acid, in the
presence of boric acid or other boron compounds yielding boric acid when used
together with sulphuric acid, and it is mentioned in the said Specification that the
boric acid exerts a very favourable influence in the process.
According to the researches of my foreign correspondents, when dinitro-
naphthalene is heated with concentrated sulphuric acid in the presence of boric
acid or the like, it does not yield naphthazarine as chief product (which is known
to be the chief product when the process is carried out without boric acid), but a
series of colouring matters is formed entirely different from naphthazarine.
My foreign correspondents have already succeeded in isolating two dye-stuffs
hereinafter termed "dye-stuff A" and "dye-stuff B," which can easily be separated
one from the other by reason of the difference in their solubility in dilute
sulphuric acid.

page_text: or these two dye-stuffs is illustrated by the following example,.
the parts being by weight.
EXAMPLE.
10 parts of alpha, alpha, dinitro naphthalene and 15 parts of crystallized boric
acid, are mixed with 250 parts of sulphuric acid (66 degrees Baumé). The
mixture is heated at from 200 to 220 degrees Centigrade. A moderate action
takes place, the solution assuming a reddish colour, and gas being disengaged. As
soon as the liquid has assumed a deep bluish-red colour, it is allowed to cool, and is
then poured into 1000 parts of water. After heating the liquid to boiling, it is
filtered while hot. A small quantity of unaltered dinitronaphthalene and of a
colouring matter which dissolves in soda lye producing a dull violet-red coloured
solution remain on the filter. The aforesaid "dye-stuff A separates as a black
violet precipitate from the hot filtrate as it cools, and is filtered off; the "dye-
stuff Bis precipitated on adding common salt to the filtrate, and is also separated
by filtration.
"
My foreign correspondents have also found, that, as in the production of
naphthazarine, intermediate products are also formed in the process illustrated by
the above example, and that these intermediate products can be converted into the
corresponding dye-stuffs by boiling with dilute acids.
The above named dye-stuffs A and B possess the following properties.
The "dye-stuff A "dissolves with difficulty in cold water, but more easily in hot
water, producing a bluish-red coloured solution. It easily dissolves in glacial
acetic acid, producing a beautiful bluish-red coloured solution. Its solution in
ammonia shews a violet-red colour, whilst the solution in soda-lye possesses a
violet colour. It dissolves in concentrated sulphuric acid, yielding a currant-red
coloured solution. It produces on wool mordanted with chromium salts, from
violet to deep-black shades possessing a reddish hue.
The "dye stuff B" dissolves with difficulty in cold water, more easily in cold
dilute sulphuric acid, and readily in hot water, producing a magenta-red coloured
solution. It is dissolved with ease by glacial acetic acid, affording a cherry-red
solution, and also with ease by concentrated sulphuric acid, forming a yellowish-red
coloured solution. Its solution in ammonia is carmine red, whilst its solution in
soda-lye has a magenta-red colour. The shades produced therewith on chromated
wool are similar to those obtained by means of the above "dye-stuff A," but possess
a considerably bluer hue than those of the latter colouring-matter.
The two dye-stuffs differ in a very distinct manner from naphthazarine as regards
the colours they afford on dissolving them in soda-lye, naphthazarine yielding a
beautiful blue coloured solution.
In order to produce the above or similar mordant-dyeing colouring matters from
alpha, alpha, dinitronaphthalene, my foreign correspondents do not limit themselves
to the directions given in the aforesaid example, as the operations can be varied.
For instance, instead of boric acid, salts of boric acid, or boron trichloride, or
other boron compounds yielding boric acid when used together with sulphuric acid,
can be taken; stronger or weaker sulphuric acid can be used in place of the
sulphuric acid at 66 degrees Baumé, the operation being in this case carried on at
a relatively lower or higher temperature, and heating being continued during a
longer or shorter period. Such or similar modifications do not alter the nature of
this invention, as it in general relates to the production of dye stuffs by heating
alpha, alpha, dinitronaphthalene with sulphuric acid in the presence of boric acid
or other boron compounds yielding boric acid, when used together with sulphuric
acid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to ine
from abroad, I declare that what I claim is :-
1 T1

page_text: mordants, from alpha, alpha, dinitronaphthalene, and concentrated or monohydrated
or moderately fuming sulphuric acid and boric acid, or other boron compounds
yielding boric acid when used together with sulphuric acid.
2. The process for producing colouring matters capable of dyeing with the aid
of mordants, which process consists in heating at elevated temperatures alpha,
alpha, dinitronaphthalene, with concentrated or monohydrated or moderately
fuming sulphuric acid, and boric acid, or other boron compounds yielding boric acid
when used together with sulphuric acid; pouring the mixture, when cool, into
water, then heating the liquid to boiling, and isolating the dye-stuffs thus produced
in any suitable manner.
.
3. As new products of manufacture, the new dye-stuffs produced by the process
herein before defined, or by any other process affording the same result.
Dated this 8th day of November 1894.
NEWTON & SON,
Agents for the Applicant.