A Black Cotton Dyestuff and Process for the Production of the same.
Year: 1898

page_text: [Communicated from abroad by Messrs. DAHL AND COMPANY, of Barmen, in the
Empire of Germany.]
A Black Cotton Dyestuff and Process for the Production of the same.
I, ADOLF BANG, of 55A, St. Paul's Street, in the City of Leeds, Dye-stuff
Merchant, do hereby declare the nature of this invention to be as follows:-
This invention is based on the observation made by my correspondents that
by melting dinitrodiphenylamine-mono-sulphonic acid with sulphide of sodium
and a little sulphur a dyestuff is obtained, which is soluble in alkalies, and
which dyes unmordanted cotton a fast black in either a hot or a cold bath.
The dinitro diphenylamine-mono-sulphonic acid is produced by heating to boil-
ing for some hours aniline sulphonic acid with dinitrobenzol-chloride in an
aqueous solution.
The production of the dyestuff takes place in the following manner;
60 kg. of sulphide of sodium (NaS +9 Aq.) are melted in an iron vessel with
5 kg. of water and 10 kg. of dinitro-diphenylamine-mono-sulphonic acid are
added. After the first violent reaction is over, 8 kg. of sulphur are added, and
the mass then heated to 160° C. until the melted mass is dry; and it is then
further heated to from 2000-250° C. whereupon the mass again melts. This
temperature is now kept up under well stirring until the remelted mass again
becomes dry, when the process is finished.
The dyestuff thus obtained forms black porous pieces, which dissolve in water
with a greenish black colour. On acidifying the solution, a brownish black powder
is precipitated, which will redissolve in alkalies with a greenish colour.
Unmordanted cotton dyes in light shades brownish green; when dyed stronger,
the colour is an intense black. The colours are, without any further-treatment,
absolutely fast.
Dated thin 11th
T
1000
A Black Cotton Dyestuff and Process for the Production of the same.
I, ADOLF BANG, of 55A, St. Paul's Street, in the City of Leeds, Dye-stuff
Merchant, do hereby declare the nature of this invention and in what manner
[Price 8d.]

page_text: the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This invention is based on the observation made by my correspondents that
by melting dinitrodiphenylamine-mono-sulphonic acid with sulphide of sodium
and a little sulphur, a dyestuff is obtained, which is soluble in alkalies, and
which dyes unmordanted cotton a fast black, in either a hot or cold bath.
The dinitrodiphenylamine-mono-sulphonic acid is produced by heating to boil-
ing for some hours aniline sulphonic acid with dinitrobenzol-chloride in an
aqueous solution.
The production of the dyestuff takes place in the following manner;
60 kg. of sulphide of sodium (NaS +9 Aq.) are melted in an iron vessel with
5 kg. of water, and 10 kg. of dinitrodiphenylamine-mono-sulphonic acid are
added. After the first violent reaction is over, 8 kg. of sulphur are added, and
the mass then heated to 160° C. until the melted mass is dry; and it is then
further heated to from 200° to 250° C.; whereupon the mass again melts. This
temperature is now kept up, under well stirring, until the remelted mass again
becomes dry, when the process is finished.
The dyestuff thus obtained forms black porous pieces, which dissolve in water
with a greenish black colour. On acidifying the solution, a brownish black powder
is precipitated, which will redissolve in alkalies with a greenish colour.
Unmordanted cotton dyes in light shades brownish green; when dyed stronger,
the colour is an intense black. The colours are, without any further treatment,
absolutely fast.
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:
1. The process for the production of a black cotton dyestuff by melting dinitro-
diphenylamine-mono-sulphonic acid with sulphur and sulphide of sodium at tem-
peratures between 150° and 250° C. substantially as set forth.
2. Black dyestuffs produced according to the process the subject matter of
Claim 1.
T
CL 1
P
1000
J. CLARK JEFFERSON, F.I.P.A.
30, Park Row, Leeds, Agent for Applicant.