THE MANUFACTURE OF NEW COLORING MATTERS
Year: 1884

page_text: I DOTTO HOFFMANN of Mainkur near Frankfort on Main in the Empire of
Germany Chemist do hereby declare the nature of my Invention for "THE
MANUFACTURE OF NEW COLORING MATTERS" to be as follows:-
I have found that by the action of certain metals or of their salts upon certain
nitrosonaphtolsulphonic acids, new combinations are formed, containing these
metals, which however are not indicated by the ordinary chemical reactions.
The nitrosonaphtolsulphonic acids or their salts are formed by the action of
molecular quantities of nitrite of sodium and muriatic acid upon the naphtol-
sulphonic acids or their salts dissolved or finely suspended in water. The nitroso
compounds can also be used in the solutions in which they were formed.
In order to produce a green coloring matter which I call naphtol-green I proceed
as follows:
27.5 kilos. of nitrosobetanaphtolmonosulphonate of sodium (prepared from the
monosulphonic acid of Schaeffer) are dissolved in 100 litres hot water, I let this
solution cool down and then I add 20 litres of dissolved perchloride of iron
containing 5 kilos. of Fe, Cl. The yellow brownish solution becomes dark brown
and finally deep black. After several hours standing the excess of iron is
precipitated by an alkali and the filtered solution showing a pure green color is
evaporated. The green dye stuff can be obtained in a purer state by crystallization
out of diluted alcohol or by precipitation from the alkaline aqueous solution by
the solution of a lend salt, the coloring matter deposits in form of an insoluble
basic leadsalt which is washed with water and rendered soluble with diluted
sulphuric acid or with the sulphate or carbonate of an alkali.
In place of the monosulphonic acid of Schaeffer all other naphtolsulphonic acids
may be used with exception of the betanaphtolalphamonosulphonic acid and the
betanaphtolgammadisulphonic acid.
Naphtol-green prepared with the alphanaphtolmonosulphonic acid corresponding
with the difficultly soluble alphanaphtylamine sulphonic acid is characterized by
its being difficultly soluble and crystallizing easily; it is of a yellow shade.
In place of the perchloride of iron other iron salts may be used to the same
effect; metallic iron and salts of the protoxyd of iron act also in a similar manner
upon nitrosonaphtolsulphonic acids and according to the quantity of iron or
protoxyd salts employed the color obtained can be varied from a green to a dark
olive shade the coloring matters formed in this manner are inixtures of naphtol-
green with other combinations of a dark brown color.

page_text: The figures I have given in the above example with regard to dilution,
temperature during the reaction, quantity of perchloride of iron and manner of
purifying the dye stuff may be altered within wide limits. I also obtain similar
results by starting from the naphtolsulphonic acids, in this case I add to their
aqueous solution an iron salt and then I treat the mixture with nitrous acid.
In order to produce brown and yellow colors I substitute in the above described
method of producing a green color in place of the perchloride of iron an equivalent
quantity of a cobalt salt, I obtain, by operating in the very same manner brown
coloring matters. The alpha compound has a reddish shade, the beta compound a
yellowish one. Nickel-salts produce yellow colors.
The dye-stuffs berein described belong to a new class of metallo-organic
compounds. In an acidulated dyebath they dye silk and wool and other materials-
An excess of acid will make the color disappear, it comes back on the neutralization
of the acid.
D
GOLL
T100 A

page_text: I DR OTTO HOFFMANN of Mainkur near Frankfort on Main in the Empire of
Germany Chemist, do hereby declare the nature of my Invention for "THE
MANUFACTURE OF NEW COLORING MATTERS and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
I have found that by the action of certain metals or of their salts upon certain
nitrosonaphtolsulphonic acids, new combinations are formed, containing these
metals, which however are not indicated by the ordinary chemical reactions
The nitrosonaphtolsulphonic acids or their salts are formed by the action of
molecular quantities of nitrite of sodium and muriatic acid upon the napthol-
sulphonic acids or their salts dissolved or finely suspended in water. The nitroso
compounds can also be used in the solutions in which they were formed.
PRODUCTION OF A NEW GREEN COLORING MATTER WHICH I CALL
NAPTHOL GREEN.
27.5 kilos. of nitrosobetanaphtolmonosulphonate of sodium (prepared from the
monosulphonic acid of Schaeffer) are dissolved in 100 litres hot water, I let this
solution cool down and then I add 20 litres perchloride of iron containing 5 kilo.
of Fe, Cl. The yellow brownish solution becoines dark brown and finally deep
black. After several hours standing, the excess of iron is precipitated by an
alkali, and the filtered solution, showing a pure green color is evaporated
The green dyestuff can be obtained in a purer state by crystallization out of
diluted alcohol or by precipitation from the alkaline aqueous solution, by a solution
of a lead salt, the coloring matter deposits in form of an insoluble basic lead salt,
which is washed with water and rendered soluble with diluted sulphuric acid or
with the sulphate or carbonate of an alkali.
In place of the monosulphonic acid of Schaeffer all other naptholsulphonic acids
may be used with exception of the betanaphtolalphamonosulphonic acid and the
betanaphtolgammadisulphonic acid.
Naphtol-green prepared with the alphanaphtolmonosulphonic acid, corresponding.
with the difficultly soluble alphanaphtylamine-sulphonic acid is characterized by
being difficultly soluble and crystallizing easily, it is of a yellow shade.
In place of the perchloride of iron other iron salts may be used to the same
effect, metallic iron and salts of the protoxyd of iron act also in a similar manner
upon nitrosonaphtolsulphonic acids and according to the quantity of iron or
protoxyd salts employed the color which is obtained can be varied from a green
to a dark olive shade, the coloring matters formed in this way are mixtures of
naphtol-green with other combinations of a dark brown color. The figures I have
given in the above example with regard to dilution, temperature during the
reaction, quantity of perchloride of iron and manner of purifying the dyestuff may
be altered within wide limits. I also obtain similar results by starting from the
naptholsulphonic acids adding an iron salt to their aqueous solution and then
treating the mixture with nitrous acid.

page_text: by operating in the very same manner, brown coloring matters. The alpha
compound has a reddish shade, the beta compound a yellowish one.
Nickel salts produce under the same or similar circumstances yellow colors.
The dyestuffs described belong to a new class of metallo-organic compounds. In
an acidulated dyebath they dye silk and wool, it is adviseable to add to the
dyebath a small quantity of a salt of that metal, which has been used for the
production of the respective color. An excess of acid will make disappear the color,
which comes back by neutralization of the acid.
All the colors herein described may also be formed on the material that is to be
dyed. For this purpose the acidulated dye bath has to contain a fit nitrosonaphtol-
sulphonic acid or a salt of one of these acids and a salt of iron cobalt or nickel
according to the color required.
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:
First. The new coloring matters herein specified.
Second. The method or methods herein described for producing green, brown,
and yellow coloring matters by the action of iron cobalt or nickel upon the named
nitrosonaphtolsulphonic acids.
Third. The production of the described colors upon the material to be dyed by
dyeing with the named nitroso-compounds in presence of the named metallic
combinations in acidulated baths.