The Manufacture or Production of Dyestuffs for Cotton.
Year: 1899

page_text: Date of Application, 24th Apr., 1899
Complete Specification Left, 18th Jan., 1900-Accepted, 24th Feb., 1900
PROVISIONAL SPECIFICATION.
[Communicated from abroad by the Farbenfabriken vormals FRIEDRICH Bayer & Co.,
of Elberfeld, Germany.]
L
The Manufacture or Production of Dyestuffs for Cotton.
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 found that valuable dye-stuffs for cotton are
obtained, if mono or dialkylized derivatives from amidodinitrodiphenylamine are
heated with alkaline sulphides and sulphur, or with substances or mixtures acting in
the same or in a similar manner.
It may be remarked that the said alkylized compounds can be easily produced by
the action of dinitrochlorobenzene or mono-alkylized or unsymmetrically dialkylized
diamines of the benzene series. Thus, for instance, dimethylamidodinitrodiphenyl-
amine is obtained, if 13-4-dinitrochlorobenzene is allowed to act on para-amido-
dimethylaniline.
In order to illustrate the production of the new dye-stuffs, the following example
is given, the parts being by weight.
EXAMPLE.
To a mixture prepared from 80 parts of dry sodium sulphide, 60 parts of sulphur
and 30 parts of water, (which mixture is heated in an iron vessel provided with a
stirring apparatus), 40 parts of the above mentioned para-dimethylamidodinitro-
diphenylamine are added, with stirring, at about from 90 to 100 degrees Centigrade.
The temperature is then slowly raised to about from 150 to 160 degrees Centigrade,
the mass being stirred the while. When the whole mass becomes solid, the iron
vessel is closed, and the temperature of the mixture is gradually raised to from
280 to 290 degrees Centigrade. The melt is kept at this temperature until there is
no longer an increase in the quantity of the dye-stuff formed during the reaction.
Subsequently, the melt is allowed to cool. When cool, it represents a dark solid
mass which can easily be pulverized. It dissolves in water with a yellowish-olive
color, and can be directly used for dyeing. On unmordanted cotton, in boiling baths
containing common salt and sodium sulphide, intense olive green shades are obtained,
which are fast to washing and to light. When treated with oxidizing agents, brighter
green shades are obtained.
The process proceeds in an analogous manner if, instead of dimethylamidodinitro-
diphenylamine, others of the above mentioned alkylized derivatives of amidodinitro-
diphenylamine are used.
As a matter of course, my foreign correspondents do not intend to confine them-
selves to the particulars given in this example, as it is merely typical, and can be
varied within wide limits.

page_text: To a mixture prepared from 80 parts of dry sodium sulphide, 60 parts of sulphur,
and 30 parts of water (which mixture is heated in an iron vessel provided with a stir-
ring apparatus), 40 parts of the above mentioned para-dimethylamidodinitrodiphenyl-
amine are added, with stirring, at about from 90 to 100 degrees Centigrade. The
temperature is then slowly raised to about from 150 to 160 degrees Centigrade, the
mass being continuously stirred. When the whole mass becomes solid, the iron vessel
is closed, and the temperature of the mixture is gradually raised to from 280 to 290
degrees Centigrade. The melt is kept at this temperature until there is no longer an
increase in the quantity of the dye-stuff formed during the reaction. Subsequently,
the melt is allowed to cool. When cool, it represents a dark solid mass which can
easily be pulverized. It dissolves in water with a yellowish-olive color, and can be
directly used for dyeing. On unmordaunted cotton, in boiling baths containing
common salt and sodium sulphide, intense olive-green shades are obtained, which are
fast to washing and to light. When treated with oxydizing agents, brighter green
shades are obtained.
The process proceeds in an analogous manner if, instead of paradimethylamido-
dinitrodiphenylamine, others of the above mentioned methylated derivatives of amido-
dinitrodiphenylamine, thus, for instance, dimethyl metaamidodinitrodiphenylamine,
monomethyl para amidodinitrodiphenylamine, dimethyl-ortho - amidodinitrodi-
phenylamine, or the like, are used, coloring matters being thus obtained which like-
wise dye unmordanted cotton, in boiling baths containing common salt and sodium
sulphide, olive-green shades.
-
As a matter of course, my foreign correspondents do not intend to confine them-
selves to the particulars given in this example, as it is merely typical, and can be
varied within wide limits.
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 me
from abroad), I declare that what I claim is :-
1. The process for the production of new dye-stuffs for cotton, which process
consists in treating mono- or unsymmetrically dimethylated amidodinitrodi-

page_text: phenylamines, with alkaline sulphides and sulphur, or with substances or mixtures
acting in the same or in a similar manner, substantially as hereinbefore
described.
2. As new articles of manufacture, the new dye-stuffs for cotton obtainable by the
process herein before described and claimed.