IMPROVEMENTS IN THE MANUFACTURE OF DYES
Year: 1883

page_text: LETTERS PATENT to Gustav Adolph Bang of Leeds in the County of York
trading as Theodor Bang import and export merchant for an Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF DYES" communicated to him
from abroad by Gustav Adolph Dahl, Ernst Dahl and Rudolph Dahl trading
as Dahl and Company of Barmen in the German Empire
PROVISIONAL SPECIFICATION left by the said Gustav Adolph Bang at the
Office of the Commissioners of Patents on the 5th May 1883.
"
GUSTAV ADOLPH BANG of Leeds in the County of York, trading as Theodor
Bang, import and export merchant "IMPROVEMENTS IN THE MANUFACTURE OF
DYES (A communication to me from abroad by Gustav Adolph Dahl, Ernst
Dahl and Rudolph Dahl trading as Dahl and Company of Barmen in the German
Empire)
Firstly. The production of Azo dyes by the action of Diazobenzole, Diazotoluole,
Diazoxylole, Diazoazobenzole, Diazoazotoluole, Diazoazooxylole and compound
Diazoazo combinations, Diazoanisol, Diazonaphthaline and the corresponding
sulphates, on monosulphate of alphanaphthaline derived from naphthaline.
Secondly. The production of an azo dye by direct conversion of monosulphate of
Diazoalphanaphthaline Naphthaline is converted in the manner known into the
monosulphate of naphthaline.
The soda salt of the latter is readily soluble in 90% alcohol and crystallizes out
of the solution in large needle shaped crystals, which property can be made
available for purification
Whilst the azo dyes derived from Schaffer's alpha naphtha monosulphate are
brown, those produced from the monosulphate of alpha naphthaline derived from
naphthaline are orange to blue-red
This monosulphate or acid treated with Diazobenzole, Diazotoluole and
Diazoxylole produces yellow-red and red dyes; treated with Diazoanisole,
Diazoazobenzole, Diazoazotoluole, Diazoazoxylole and their sulphates it produces

page_text: blue-red dyes, with Diazonaphthaline and monosulphate of Diazonaphthaline
scarlet-red and Bordeaux-red dyes which are distinguished by purity and
strength.
A scarlet red dye is produced in the following manner.
100 pounds of soda naphtha is dissolved in 200 gallons of water to which
52 pounds of hydrochloric acid are added and cooled to 41 degrees Fahrenheit, after
which 28 pounds of nitrate of soda are added.
After standing for some time the mono sulphate of apha-diazonaphthaline is run
off slowly into a weak alkaline solution of 100 pounds of monosulphate of
alphanaphthaline cooled likewise to 41 degrees Fahrenheit
The resulting dye is precipitated by means of salt and purified by being
redissolved.
The dye produced from the monosulphate of Diazonaphthaline and mono
sulphate of alphanaphthaline can also be readily obtained by slowly adding the
Diazo compounds produced from naphthaline to about 10 times the quantity of
water (warmed to about 90 degrees Centigrade) with the salt of an organic acid
such for example as acetate of soda or formate of soda.
The resulting dye is precipitated by means of common salt.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gustav Adolph Bang in the Great Seal Patent Office on the
5th November 1883.
"
GUSTAV ADOLPH BANG of Leeds in the County of York trading as Theodor
Bang import and export merchant "IMPROVEMENTS IN THE MANUFACTURE OF
DYES being a communication to me from abroad by Gustav Adolph Dahl, Ernst
Dahl and Rudolph Dahl, tráding as Dahl and Company of Barmen in the German
Empire,
This Invention has reference
Firstly. To the production of Azo Dyes by the action of Diazobenzol,
Diazotoluol, Diazoxylol, Diazoazobenzol Diazoazotoluol, Diazoazoxylol and
compound diazoazo combinations Diazoanisol, Diazonaphthaline, and the
corresponding sulphates, on monosulphate of alphanaphthaline derived from
naphthaline.
Secondly To the production of an azo dye by direct conversion of monosulphate
of Diazoalphanaphthaline.
Naphthaline is converted in the manner known into the corresponding
monosulphate of alphanaphthaiine
The soda salt of the latter is readily soluble in 90 per cent of alcohol and
crystallizes out of the same in large needle shaped crystals, which property can be
made available for its purification
Whilst the Azo dyes derived from Schoeffer's alpha-naphtha monosulphate are
brown those produced from the monosulphate of alphanaphthaline derived from
naphthaline are orange to blue red.
This monosulphate (or acid) treated with Diazobenzol Diazotoluol and Diazoxylol
produces yellow-red and red dyes; treated with Diazoanisol, Diazoazobenzol,
Diazoazotoluol, Diazoazoxylol and their sulphates it produces blue red dyes; and
with Diazonaphthaline and Diazonaphthaline-monosulphate scarlet red and
Bordeaux red dyes, which are distinguished by purity and strength.
A scarlet red dye may be produced in the following manner. 100 lbs of soda
naphtha is dissolved in 200 gallons (= 1000 Litres) of water to which 52 lbs of
hydrochloric acid are added and cooled to 41 degrees Fahrenheit after which
28 pounds of nitrate of soda are added. After standing for some time the
monosulphate of alphadiazonaphthaline is run off slowly into a weak alkaline
solution of 100 pounds of monosulphate of alphanaphthaline cooled likewise to
41 degrees Fahrenheit.
The resulting dye is precipitated by means of salt and purified by being
redissolved
The dye produced from the monosulphate of Diazonaphthaline can also be
readily obtained by slowly adding the diazo compounds produced produced from
naphthaline to about 10 times the quantity of water (warmed to about 90 degrees
Centigrade) with the salt of an organic acid such as for example acetate of soda,
or formate of soda.
The resulting dye is precipitated by means of common salt.
Having now described the nature of the said Invention I would have it
understood that I do not limit myself to the exact details herein set forth as the
quantities and strengths of the various ingredients will vary with the nature or
strength of the dye to be produced; but what is claimed is
Firstly The production of Azo Dyes by the action of Diazobenzol, Diazotoluol,
Diazoxylol, Diazoazobenzol, Diazoazoxylol Diazoazotoluol and compound Diazoazo

page_text: combinations, Diazoanisol Diazonaphthaline and the corresponding sulphates, on
monosulphate of alphanaphthaline derived from naphthaline as described herein.
Secondly. The production of an azo dye by direct conversion of monosulphate of
diazoalphanaphthaline as described herein.
In Witness whereof I the said Gustav Adolph Bang have hereunto set my
hand and seal this first day of September in the Year of Our Lord One
thousand eight hundred and eighty three.
GUSTAV ADOLPH BANG (L.S.)