Improvements in the Manufacture of Azo Dyes.
Year: 1887

page_text: Date of Application, 30th Nov., 1887
Complete Specification Left, 26th June, 1888
Complete Specification Accepted, 3rd Aug., 1888
Improvements in the Manufacture of Azo Dyes.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman, do hereby declare the nature of this Invention which has been com-
municated to me from abroad by the Farbenfabriken vormals Friedrich Bayer & Co.
of Elberfeld in the Empire of Germany, to be as follows:-
This Invention has for its object the manufacture or production of dyes or dye-stuffs
of from light to dark blue black colour which are capable of dyeing cotton goods in
an alkaline bath by direct action without the employment of a mordant, and it consists
essentially in combining the tetrazo compounds of para diamines or of their sulpho- or
carbo-acids with alpha Naphthylamine in the first place, the amido azo compounds
thus obtained being again diazotised and caused to act upon amides, phenols or the
sulpho or carbo acids thereof.
According to this Invention violet blue to blue black direct dyeing azo dyes are
manufactured by the action of the tetrazo compounds of those amido azo compounds
which result when one molecule of the above mentioned paradiamine is diazotised and
combined with one or two molecules of alpha naphthylamine two molecules of alpha
or beta naphthol dioxy-naphthaline or their mono and disulpho acids or the aforesaid
tetrazo compound is caused to act upon one molecule of an amide, a phenol or their
sulpho or carbo acids so as to obtain an intermediate product which contains a free
diazo group and is consequently capable of combining with a second molecule of
another amide or phenol or the sulpho- or carbo-acids thereof to form a dyestuff.
Blue black dyestuffs are manufactured from acetyl para phenylenediamine and acetyl
diamido azo benzol by combining the diazo compounds of this substance with one
molecule of alpha naphthylamine and repeatedly diazotising the same and bringing it
into contact with amides, phenols or the sulpho or carbo acids thereof the acetyl group
being afterwards separated by known means then repeating the diazotising and again
combining with amides, phenols and their sulpho or carbo acids.
The following description explains the application of the invention to the production
of certain dyestuffs by way of example, from which the method of proceeding in order
to obtain others of the same class or series will be readily understood by those skilled
in the art.

page_text: Dye obtained from benzidine. One molecule alpha naphthylamine and two mole-
cules alpha naphthol alpha 'mono sulpho acid. About one hundred parts by weight of
benzidine sulphate in a fine state of division are placed in suspension in water and
mixed with about fifty parts by weight of hydrochloric acid at 21° Beaumé.
This solution is cooled by means of ice and a solution composed of twenty-five parts
by weight of sodium nitrite in twenty five parts by weight of water is poured slowly
into it.
This solution is then mixed with an aqueous solution of about twenty six parts by
weight of alpha naphthylamine in weak or highly diluted hydrochloric acid and the
free mineral acid is neutralized by rapidly introducing a solution of sodium acetate.
The mixture then assumes a brown colour and is allowed to stand until a drop of the
deposit upon blotting paper leaves a colourless ring which does not show any colour on
the application of an alkaline solution of naphthol sulpho-acid."
The deposit thus formed is separated by filtration and stirred with water into a thin
paste. About fifty parts by weight of hydrochloric acid at 21° Beaumé are then
added and the second diazotising is performed with the application of about thirteen
parts by weight of sodium nitrite.
After standing for about twelve hours the diazo compound thus obtained is poured
into a solution, maintained alkaline to the last with soda and consisting of about eighty
eight parts by weight of a soda salt of alpha naphthol alpha mono sulpho acid. A blue
black deposit or precipitate is then formed which when separated by filtration and
dried forms a dye-stuff by means of which cotton can be dyed a blue-violet colour,
being bluer than that obtained with the dye produced with the employment of one
molecule of benzidine and two molecules of alpha naphthol alpha mono sulpho
acid.
Dyestuff obtained from benzidine with one molecule of alpha naphthylamine,
one molecule of alpha naphthionic acid and one molecule of alpha napthol sulpho acid.
When the diazo compound of the intermediate product of benzidine and one molecule
of alpha naphthylamine described in the preceding example is poured into a solution
of a quantity of a soda salt of an alpha naphthionic acid (alpha naphthionate of soda)
corresponding to one molecule (or about forty-two parts by weight) and acetate of
soda is added until the mineral acid has disappeared a brown precipitate or deposit is
obtained after standing for some time which precipitate also contains a free diazo
group and combines with naphthol sulpho acids to form dye stuffs of from red to blue
violet colour.
Dyes with two molecules of alpha naphthylamine and two molecules of alpha naphtol
sulpbo acid.
When, in the process firstly hereinbefore described, two molecules of alpha
naphthylamine are employed in place of the one molecule above referred to and are
allowed to act upon the diazo compound of the benzidine, that is to say, when about
fifty parts by weight of alpha naphthylamine are allowed to act upon about one
hundred parts by weight of diazotised benzidine sulphate a known amido azo substance
insoluble in water is obtained. After standing for about twelve hours this substance
is separated by filtration and washed with water slightly acidulated with hydrochloric
acid in order to remove all excess of hydro chlorate of alpha naphthylamine after
which it is mixed with a small quantity of water with the addition of about fifty parts
by weight of hydro chloric acid at 21° Beaumé and about twenty five parts by weight
of sodium nitrite in solution in water.
After again standing for about twelve hours a diazo compound, soluble in water
with great difficulty, is formed which yields a blue black precipitate on being poured
into a solution, maintained alkaline to the end, of about eighty eight parts by weight
of a soda salt of alpha naphthol sulpho acid.
By boiling filtering and drying this product a dyestuff is obtained of a beautiful
blue-black colour.
Dyestuffs from benzidine and two molecules of alpha naphthylamine the product
being treated with sulphuric acid and then after diazotizing with two molecules. of
alpha naphthol sulpho acid.

page_text: A very excellent and beautiful blue black dye stuff is obtained by the following
process:-
:
When the well known insoluble dye obtained by the action of two molecules of
alpha naphthylamine upon diazotised benzidine is rendered soluble by treatment with
sulphuric acid and the product from about 100 parts by weight of benzidine sulphate
is then treated in the known manner being dissolved in water and mixed with about
fifty parts by weight of hydrochloric acid at 21° Beaumé and about twenty five parts
by weight of sodium nitrite in solution in water a diazo compound is obtained which
is soluble with difficulty and after pouring or flowing into an alkaline solution of about
eighty eight parts by weight of a soda salt of alpha naphthol alpha mono sulpho acid
yields a dye which dyes the goods a deep blue to black.
Tolidine yields a somewhat weaker and dianisidine a still less useful product.
Dye from para-phenylene-diamine and diamido azo benzol.
In making this dye it is preferable to apply the acetyl combinations of mono acetyl
para-phenylene-diamine and mono acetyl diamido azo benzol but this is not absolutely
essential.
Alpha naphthol sulpho acid, azo benzol azo naphthaline, azo alpha naphthol sulpho acid.
About fifty parts by weight of acetyl para-phenylene-diamine are dissolved in about
eight hundred parts by weight of water and about fifty parts by weight of hydrochloric
acid at 21° Beaumé. Into this mixture is slowly poured a solution of about twenty-
three parts by weight of nitrite.
After standing for from about one to two hours the formation of the diazo compond
is completed and this product is poured into a solution of about forty seven parts by
weight of alpha naphthylamine in highly diluted hydro-chloric acid. The product of
reaction forins very rapidly and in a few hours the liquid thickens and becomes a
stiff paste.
In order to remove any alpha-naphthylamine that may have remained unconverted
filtering is performed after standing for about one hour and the product is repeatedly
washed or elutriated in water acidulated with hydro-chloric acid.
The azo substances thus treated are then washed or elutriated with about seven
hundred parts by weight of water and about fifty parts by weight of hydrochloric acid
at 21° Beaumé and mixed with an aqueous solution of about twenty-three parts by
weight of nitrite.
After standing for about twenty four hours the diazo compound formed is poured
into an alkaline solution of about eighty parts by weight of a soda salt of alpha
naphthol sulpho acid.
In order to separate the acetyl group from the dye which is immediately formed
the product is filtered and washed or elutriated with about one thousand parts by
weight of water and heated to boiling with the addition of about two hundred parts
by weight of soda lye at about 35° Beaumé. After simmering for about two hours
the separation of the acetyl group is completed.
The dissolved soda salt of para amido benzol azo naphthaline azo naphthol sulpho
acid forming a fine blue dye stuff is mixed with a watery solution of about twenty
three parts by weight of nitrite and about fifty parts of hydrochloric acid at 20° Beaumé
and allowed to stand for about twenty four hours.
The resulting diazo compound is placed in a solution of about eighty parts by weight
of alpha naphthol sulpho acid and about one hundred parts by weight of soda in
about five thousand parts by weight of water. A dyestuff is immediately obtained
giving a very fine indigo blue colour.
Dyestuffs from amido benzol azo benzol azo amido benzol.
This substance is very readily obtained from para-phenylene-diamine. When the
para-phenylene-diamine is diazotised in a strong hydrochloric acid solution being well
cooled at the time and the solution in the highest degree of concentration is poured
into three times the quantity of aniline corresponding to the nitrite contained therein
the diazo amido compound is formed after stirring the mixture for a certain time.
After standing for about twenty four hours a small quantity of aniline and hydro-
chloric acid is added and the temperature is raised to about 40 degrees centigrade.

page_text: The entire transformation or conversion of the diazo amido compound into the amido
azo compound is completed.
The product is separated by filtration elutriated with hydrochloric acid and filtered
again to remove any aniline that may be present after which by the addition of
ammonia it is changed into the yellow base.
Production of the dye stuff alpha naphthol sulpho acid azo naphthalin azo benzol
azo benzol azo benzol azo naphthalin azo alpha naphthol sulpho acid.
About one hundred parts by weight of amido benzol azo benzol azo amido benzol
are elutriated with about one thousand five hundred parts by weight of water and one
hundred parts by weight of hydrochloric acid at 21° Beaumé. A watery solution of
about forty four parts by weight of sodium nitrite is then poured into this mixture
the latter being effectually cooled.
To complete the formation of the diazo compound the liquid is allowed to stand
for about 24 hours and a weak hydrochloric acid solution of about ninety parts by
weight of alpha naphthylamine is poured into the resulting diazo compound.
The formation of the products of reaction proceeds very rapidly when the free
mineral acid is neutralized by acetate of soda. It is then acidulated with hydrochloric
acid, separated by filtration and clutriated with water containing hydrochloric acid
to remove the alpha naphthylamine.
The new azo substance is suspended in about one thousand parts by weight of
water and about one hundred parts by weight of hydro-chloric acid at 21° Beaumé a
solution of about ninety parts by weight of nitrite being added.
After standing for about twenty four hours the diazo compound formed is caused
to flow into a solution of about one hundred and sixty parts by weight of the soda
salt of alpha naphthol sulpho acid maintained alkaline by soda. The dye stuff which
is immediately formed produces a grey black.
In all these examples there may be employed in place of the tetrazo compounds
herein before specified any other para-diamine such as benzidine, tolidine, diamido
diphenol ether, diamido stilbene, diamido fluorene, diamido azo benzol, diamido azo
toluol, diamido azo xylol, phenylenediamine, amido benzol azo benzol, azo amido
benzol, naphthylene diamine or the sulphones, sulpho acids or carbo acids thereof.
Dated this 30th day of November 1887.

page_text: J, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman do hereby declare the nature of this Invention which has been com-
municated to me from Abroad by The Farbenfabriken vormals Friedrich Bayer & Co.
of Elberfeld in the Empire of Germany and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
This Invention has for its object, the manufacture or production of dyes or dye
stuffs varying in colour from light to dark blue-black which are capable of dyeing
cotton goods in an alkalino bath without the employment of a mordant and it consists
essentially in combining the tetrazo-compounds of para-diamines or of their sulpho- or
carbo- acids with alpha-naphthylamine in the first place, the amido-azo-compounds
thus obtained being again diazotised and caused to act upon amines, phenols or the
sulpho- or carbo-acids thereof.
According to this Invention violet-blue to blue-black azo dyes which dye cotton
directly are manufactured by the action of the tetrazo-compounds of those amido-azo-
compounds which result when one molecule of the para-diamine is diazotised and
combined with one or two molecules of alpha-napthibylamine, upon two molecules of
alpha- or beta-naphthol, dioxynaphthalene, metaphenylenediamine, or their mono- and
disulpho acids; or the aforesaid tetrazo-compound is caused to act upon one molecule
of an amine or plienol or of their sulpho- or carbo-acids so as to obtain an intermediate
product which contains a free diazo-group and is consequently capable of combining
with a second molecule of another amine diamine or phenol or the sulpho- or carbo-
acids thereof to form a dyestuff.
Blue-black dye stuffs are manufactured from acetyl-para-phenylenediamine and
acetyl-diamido-azo-benzene by combining the diazo-compound of either substance
with one molecule of alpha-naphthylamine thon diazotising the product and bringing
the new diazo-compound into contact with amines, phenols or the sulpho- or carbo-
acids thereof, the acetyl group being afterwards separated by known means and the
diazotising again repeated and the product combined with an amine, diamine, phenol
or the sulpho- or carbo-acid thereof.
Dyes similar to those derived from para-phenylenediamine can be manufactured
from alpha-naphthylenediamine, but it is preferable to use the acetyl derivative thereof,
monoacetyl alpha naphthylenediamine, whereof the diazo compound is combined with
one molecule of aniline toluidine or xylidine and the product is diazotised and caused
to act upon a phenol the sulpho- or carbo-acids thereof or on one molecule of alpha
naphthylamine and in this last case may be diazotised again and brought into contact
with phenols or the sulpho- or carbo-acids thereof. In order to separate the acetyl
group from the dyestuffs, they are boiled with soda-lye, the diazotising is then
repeated and the diazo-compounds are combined with amines, diamines, phenols or
the sulpho- or carbo-acids thereof.

page_text: Instead of combining alpha naphthylenediamine by means of its acetyl derivative
with only one molecule of aniline, toluidine or xylidine, it is also possible to combine
it with two molecules in a known manner, by causing the tetrazo compound of
naphthylenediamine to act upon more than two molecules of aniline. The diamidoazo-
compounds thus produced are diazotised again and combined with two molecules of an
amine or phenol or the sulpho- or carbo-acid thereof or with one molecule of an amine
phenol or the sulpho-acid of an amine or phenol and another molecule of another
amine diamine or phenol or sulpho- or carbo-acid thereof.
The following description explains the application of the invention to the production
of certain dyestuffs by way of example from which the method of proceeding in order
to obtain others of the same class or series will be readily understood.
EXAMPLE I. DYESTUFF OBTAINED FROM BENZIDINE, ONE
MOLECULE OF ALPHA-
NAPHTHYLAMINE AND TWO MOLECULES OF ALPHA-NAPHTHOL-MONOSULPHO-ACID.
About 100 parts by weight of benzidine sulphate in a fine state of division are
suspended in water and mixed with about 50 parts by weight of hydrochloric acid at
21° Beaume. This solution is cooled by means of ice and a solution composed of
25 parts by weight of sodium nitrite in 25 parts by weight of water is poured slowly
into it. The resulting solution is then mixed with an aqueous solution of about
26 parts by weight of alpha-naphthylamine in weak or highly diluted hydrochloric
acid and the free mineral acid is neutralized by rapidly introducing a solution of
sodium acetate. The mixture then assumes a brown colour and is allowed to stand
until a drop of the precipitate upon white blotting paper leaves a colourless ring which
does not show any colour on the application of an alkaline solution of beta-naphthol-
sulpho-acid.
The deposit thus formed is separated by filtration and stirred with water into a thin
paste. About 50 parts by weight of hydrochloric acid at 21° Beaumé are then added
and the second diazotising is effected by means of about 13 parts by weight of sodium
nitrite.
After standing for about 12 hours the diazo-compound thus obtained is poured into
a solution maintained alkaline throughout with soda and consisting of about 88 parts
by weight of a sodium salt of alpha-naphthol-mono-sulpho-acid. A blue-black deposit
or precipitate is then formed which when separated by filtration and dried forms a
dyestuff by means of which cotton can be dyed a blue-violet colour, being bluer than
that obtained with the dye produced with the employment of one molecule of benzidine
and two molecules of alpha-napthol-alpha-mono-sulpho-acid.
EXAMPLE II. DYESTUFF OBTAINED FROM BENZIDINE, ONE MOLECULE OF ALPHA-
NAPHTHYLAMINE, ONE MOLECULE OF ALPHA-NAPHTHYLAMINE-MONO-SULPHONIC
ACID AND ONE MOLECULE OF ALPHA-NAPHTHOL-SULPHO-ACID.
When the diazo-compound of the intermediate product of benzidine and one molecule
of alpha-naphthylamine described in the preceding example is poured into a solution of
one molecular proportion (or about 42 parts by weight) of a sodium salt of alpha-
naphthylamine monosulphonic acid and acetate of soda is added until the mineral acid
has disappeared a brown precipitate or deposit is obtained after standing for some time
which precipitate also contains a free diazo-group and combines with naphthol-sulpho-
acids to form dyestuffs of-blue-violet colour.
EXAMPLE III. PRODUCTION, OF DYESTUFF WITH TWO MOLECULES OF ALPHA-
NAPHTHYLAMINE AND TWO MOLECULES OF ALPHA-NAPHTHOL-SULPHO-ACID.
When, in the process firstly berein before described, two molecules of alpha-
naphthylamine are employed in place of the one molecule above referred to and
are allowed to act upon the diazo-compound of benzidine, that is to say when about
50 parts by weight of alpha-naphthylamine are allowed to act upon about 100 parts by

page_text: weight of diazotised benzidine sulphate a known amido-azo-substance insoluble in
water is obtained. After standing for about 12 hours this substance is separated by
filtration and washed with water slightly acidulated with hydrochloric acid in order to
remove all excess of hydrochlorate of alpha-naphthylamine, after which it is mixed
with a small quantity of water with the addition of about 50 parts by weight of hydro-
chloric acid at 21° Beaumé and about 25 parts by weight of sodium nitrite in solution
in water.
After again standing for about 12 hours a diazo-compound, which is very difficultly
soluble in water, is formed which yields a blue-black precipitate on being poured into
a solution maintained alkaline throughout the operation of about 88 parts by weight
of a sodium salt of alpha-naphthol-sulpho-acid.
By boiling, filtering and drying this product, a dyestuff is obiained of a beautiful
blue-black colour.
EXAMPLE IV. DYESTUFF FROM BENZIDINE AND TWO MOLECULES OF ALPHA-
NAPHTHYLAMINE; THE PRODUCT BEING TREATED WITH SULPHURIC ACID AND
THEN AFTER DIAZOTISING WITH TWO MOLECULES OF
ACID.
ALPHA-NAPHTHOL-SULPHO-
A very excellent and beautiful blue-black dyestuff is obtained by the following
process.
When the well known insoluble dye obtained by the action of two molecules of alpha-
naphthylamine upon diazotised benzidine is rendered soluble by treatment with
sulphuric acid and the product from about 100 parts by weight of benzidine sulphate
is then treated in the known manner being dissolved in water and mixed with about 50
parts by weight of hydrochloric acid at 21° Beaumé and about 25 parts by weight of
sodium nitrite in solution in water a diazo-compound is obtained which is soluble with
difficulty and after pouring into an alkaline solution of about 88 parts by weight of a
sodium salt of alpha-naphthol-alpha-mono-sulpho-acid yields a dyestuff which dies the
goods a deep blue to black.
Tolidine vields a somewhat weaker and dianisidine a still less useful product.
In making this dyestuff it is preferable to apply the acetyl compounds monacetyl-
para-phenylene-diamine and monacetyl-diamido-azo-benzene but this is not absolutely
essential.
EXAMPLE V.
ALPHA-NAPHTHOL-SULPHO-ACID-AZO-BENZENE-AZO-NAPHTHALENE-AZO-
ALPHA-NAPHTHOL-SULPHO-ACID.
About 50 parts by weight of acetyl-para-phenylene-diamine are dissolved in about
S00 parts by weight of water and about 50 parts by weight of hydrochloric acid at 21°
Beaumé. Into this mixture a solution of about 23 parts by weight of sodium nitrite
is slowly poured.
.
After standing for from about one to two hours the formation of the diazo-compound
is completed and this product is poured into a solution of about 47 parts by weight of
alpha-naphthylamine diluted in dydrochloric acid. The product of the reaction forms
very rapidly if acetate of soda be added and in a few minutes the liquid thickens and
becomes a stiff paste.
In order to remove any alpha-naphthylamine that may have remained unconverted
the mixture is filtered after it has stood for about 1 hour and the product is repeatedly
washed or clutriated in water acidulated with hydrochloric acid.
The azo substance thus treated is then added to about 700 parts by weight of water
and about 50 paris by weight of hydrochloric acid at 21° Beaumé and mixed with an
aqueous solution of about 23 parts by weight of sodium nitrite.

page_text: After standing for about 24 hours the diazo-compound thus formed is poured into
an alkaline solution of about 80 parts by weight of the sodium salt of alpha-naphthol-
mono-sulpho-acid.
In order to separate the acetyl group from the dyestuff which is immediately formed,
the product having been filtered off is added to about 1000 parts by weight of water
and heated to boiling point with the addition of about 200 parts by weight of soda-
lye at about 35° Beaumé. After simmering for about 2 hours the separation of the
acetyl group is completed.
The dissolved sodium salt of para-amido-benzene-azo-naphthalene-azo-naphthol-
sulpho-acid forming a fine blue dyestuff is mixed with a watery solution of about 23
parts by weight of nitrite and about 50 parts of hydrochloric acid at 20° Beaumé and
allowed to stand for about 24 hours.
The resulting diazo compound is introduced into a solution of about 80 parts by
weight of alpha-naphthol-sulpho-acid and about 100 parts by weight of soda in about
5000 parts by weight of water. A dyestuff is immediately obtained giving a very fine
indigo blue colour.
indigo blue colour.
EXAMPLE VI. ALPHA-NAPHTHOL-MONOSULPHO-ACID-AZO-BENZINE-AZO-BENZENE-
AZO-NAPHTHALENE-AZO-ALPHA-NAPHTHOL MONOSULPHO ACID.
About 50 parts by weight of acetyl para-phenylendiamine is converted in a known
manner into the diazo-compound, which is poured into a solution of about 50 parts by
weight of aniline.
After standing for about twenty four hours, the mixture is heated to fifty degrees
Centigrade and in order to remove the aniline, which has not taken part in the
reaction, hydrochloric acid is added and the insoluble product is then filtered off and
repeatedly washed with water acidulated with hydrochloric acid.
The azo-compound thus obtained, is mixed with about 600 paris by weight of water
and about 50 paris by weight of hydrochloric acid at 21° Beaumé and an aqueous
solution of about 23 parts by weight of nitrite of sodium is added.
After standing for one or two hours the formation of the diazo-compound is completed
and this product is poured into a solution of about 42 parts by weight of alpha--
naphthylamine diluted in hydrochloric acid. The product of the reaction forms very
rapidly when the free mineral acid is nentralised by acetate of soda and in a few
minutes the liquid thickens and becomes a stiff paste.
The azo substance thus obtained is without filtering (after standing for about one
hour) acidulated with hydrochloric acid and mixed with an aqueous solution of about
23 parts by weight of sodium nitrite.
After standing for about 24 hours the diazo compound is poured into an alkaline
solution of about 80 parts by weight of a sodium salt of alpha-naphthol-sulpho acid.
The dyestuff is immediately formed.
In order to separate the acetyl group from the dyestuff, the product is filtered, mixed
with 1000 parts by weight of water and heated to boiling with the addition of about
250 parts by weight of soda-lye at about 35° Beaumé. After simmering for about
two hours, the separation of the acetyl group is completed.
The dissolved sodium salt of the dyestuff is mixed with a watery solution of 23 parts
by weight of nitrite of sodium and hydrochloric acid at 20° Beaunié until the mixture
is acidulated which is then allowed to stand for about 24 hours.
The resulting diazo compound is poured into a solution of about 80 parts by weight
of a sodium salt of alpha-naphthol mono-sulpho acid.
The dyestuff is immediately formed.

page_text: the highly concentrated solution is poured into three times the quantity of aniline
corresponding to the nitrite employed in diazotising the diazo-amido-compound is
formed after stirring the mixture for a certain time.
After standing for about 24 hours a small quantity of aniline and hydrochloric acid
is added and the temperature is raised to about 40° Centigrade thus securing the
entire transformation or conversion of the diazo-amido-compound into the amido-azo-
compound.
The product is separated by filtration, clutriated with hydrochloric acid and the
solution filtered off in order to remove any aniline that may be present after which, by
the addition of ammonia it is changed into the yellow base.
EXAMPLE VII. ALPHA-NAPHTHOL-SULPHO-ACID-AZO-NAPHTHALENE-AZO-BENZENE-AZO-
BENZENE-AZO-BENZENE AZO-NAPHTHALENE-AZO-ALPHA-NAPHTHOL-SULPHO-ACID.
About 100 parts by weight of amido-benzene-azo-benzene-azo-amido-benzene are
added to about 1500 parts by weight of water and 100 parts by weight of hydrochloric
acid at 21° Beaumé. The mixture having been effectually cooled, a watery solution
of about 65 parts by weight of sodium: nitrite is then poured into it.
To complete the formation of the diazo compound the liquid is allowed to stand for
about 24 hours and a weak hydrochloric acid solution of about 130 parts by weight of
alpha-naphthylamine is then added to the resulting diazo-compound.
The reaction proceeds very rapidly when the free mineral acid is neutralized by
acetate of soda. When it is completed hydrochloric acid is added, and the product is
separated by filtration and elutriated with water containing hydrochloric acid to remove
the alpha-naphthylamine.
The new azo-substance is suspended in about 1000 parts by weight of water and
about 100 parts by weight of hydrochloric acid at 21° Beaumé and a solution of about
65 parts by weight of nitrite is added.
After standing for about 24 hours the diazo-compound which is formed is caused
to flow into a solution of about 240 parts by weight of the sodium salt of alpha-
naphthol-sulpho-acid maintained alkaline by soda. The dyestuff which is immediately
formed produces a grey black.
EXAMPLE VIII. ALPHA-NAPHTHOL SULPHO ACID-AZO-NAPHTHALENE-AZO-BENZENE-
AZO-NAPHTHOL-SULPHO-ACID.
About 100 parts by weight of acetyl naphthylene diamine are dissolved in about
100 parts by weight of water and about 100 parts by weight of hydrochloric acid at
21° Beaumé. Into this mixture a solution of about 35 parts by weight of sodium
nitrite is slowly poured.
The formed diazocompound is poured into a solution of about 100 parts by weight
of aniline. After standing for about 24 hours the mixture is heated to fifty degrees
Centigrade and in order to remove the aniline which has not taken part in the reaction
hydrochloric acid is added and the insoluble product is then filtered off and repeatedly
washed with water acidulated with hydrochloric acid.
The azocompound thus obtained is mixed with 1000 parts by weight of water and
about 100 parts by weight of hydrochloric acid at 21° Beaumé and an aqueous solution
of about 35 parts by weight of nitrite of sodium is added.
After standing for about 24 hours the formed diazocompound is poured into an
alkaline solution of about 120 parts by weight of a sodium salt of alpha-naphthol-
sulpho acid. The dyestuff is immediately formed.
In order to separate the acetyl group from the dyestuff, the product is filtered mixed
with 100 parts by weight of water and heated to boiling with the addition of about
B

page_text: The dissolved sodium salt of the dyestuff is mixed with a water solution of 35 parts
by weight of nitrite of sodium and hydrochloric acid until the mixture is acidulated,
which is then allowed to stand for about 24 hours. The resulting diazocompound is
poured into a solution of 120 parts by weight of a sodium salt of alpha naphthol
mono-sulpho acid. The dyestuff is immediately formed.
EXAMPLE IX. ALPHA-NAPHTHOL SULPHO ACID-AZO-BENZENE-AZO-NAPHTHALENE-AZO-
BENZENE-AZO-NAPIITHOL-SULPHO-ACID.
50 parts by weight of naphthylene diamine are converted in the known manner
into its tetrazocompound, which is poured into 100 parts by weight of aniline under
addition of some hydrochloric aniline.
After standing for about twenty four hours a small quantity of aniline and hydrochloric
acid are added; the mixture is heated to fifty degrees Centigrade, thus securing the
entire transformation or conversion of the diazoamidocompound into the amidoazo-
compound. In order to remove the aniline which has not taken part in the reaction,
hydrochloric acid is added and the insoluble product is then filtered off and repeatedly
washed with water acidulated with hydrochloric acid.
The azocompound thus obtained is mixed with about 700 parts by weight of water
and about 70 parts by weight of hydrochloric acid at 21° Beaumé and an aqueous
solution of about 45 parts by weight of nitrite of sodium is added.
After standing for about 24 hours the diazocompound is formed and is poured
into a solution of 160 parts by weight of a sodium salt of alpha naphthol-sulpho-
acid.
The dyestuff is immediately formed.
In all these examples in place of the tetrazo-compounds hereinbefore specified any
other para-diamine may be employed such as benzidine, benzidinesulphone; tolidine,
tolidinesulphone, diamidodiphenole ether, diamido-stilbene, diamido fluorene, diamido-
azo-benzene, diamido-azo-toluene, diamido azo-xylene, phenylene-diamine, naphthylene-
diamine, amido-benzene-azo-benzene-azo-amido-benzene, or the sulphones or sulpho-
acids or carbo-acids thereof.
Having now particularly described and ascertained the nature of the said inven-
tion and the manner in which the same is to be performed I declare that what
I claim is
1. In the production of dyestuffs combining the tetrazo compounds of para-diamines
such as benzidine, benzidine sulphone, tolidine, tolidine sulphone, diamido-di-phenol
ether, diamido stilbene, para-phenylen-diamine, diamido azo benzene, amido benzene-
azo-benzene-azo-amido benzene, naphthylendiamine or their sulpho- or carbo-acids,
with one or two molecules of alpha-naphthylamine, the mono or diamido-azo-
compounds thus obtained being again diazotised and caused to act upon two molecules
of an amine diamine phenol or their sulpho- or carbo-acids or with one molecule of
an amine diamine phenol or a sulpho- or carbo-acid thereof and another molecule of
another amine diamine phenol or a sulpho- or carbo-acid thereof, substantially as set
forth.
2. In the production of dyestuffs combining the diazo compound of mono-acetyl-
para-phenylene diamine or mono-acctyl amido benzene-azo-amido-benzene with alpha
naphthylamine, the resulting amido azo compound being diazotised and caused to act
upon phenols, naphthols, or their sulpho- or carbo-acids, the acetyl group being then
separated by boiling with soda-lye the product diazotised and the resulting diazo
compound combined with amines, phenols or their sulpho- or carbo-acids, or causing
them to act upon one molecule of alpha naphthylamine, diazotising this amido azo
compound and combining it with amines diamines phenols, or the sulpho- or carbo-
acids thereof substantially as set forth.

page_text: 3. In the production of dyestuffs combining the diazo-compound of mono-acetyl
alpha naphthylenediamine with aniline, toluidine, xylidine, diazotising the resulting
amido azo compounds, combining them with phenols or their sulpho- or carbo-acids,
separating the acetyl group of the dyestuffs by boiling with soda-lye, diazotising again
and causing the product to act on amines diamines phenols and the sulpho- or carbo-
acids thereof, substantially as set forth.
4. In the production of dyestuffs combining the tetrazo compounds of naphthylene-
diamine with two molecules of aniline toluidine, xylidine, diazotising the resulting
diamido azo compounds and causing them to act upon two molecules of an amine
diamine phenol or their sulpho- or carbo-acids or one molecule of an amine or phenol
or their sulpho- or carbo-acids and then on another molecule of another amine diamine
phenol or their sulpho- or carbo-acids, substantially as set forth.
5. The manufacture of dyestuffs in the several manners herein before described under
each of the foregoing examples.
6. As new articles of manufacture the dyestuffs herein described.