Production of New Red Coloring Matters.
Year: 1889

page_text: Date of Application, 8th Aug., 1889
Complete Specification Left, 19th Feb., 1890-Accepted, 15th Mar., 1890
PROVISIONAL SPECIFICATION.
Production of New Red Coloring Matters.
I, SYDNEY PITT of Sutton in the County of Surrey Gentleman (a communication
to me from abroad by Leopold Cassella & Co. of Frankfort-on-Main in the Empire of
Germany Manufacturing Chemists) do hereby declare the nature of this Invention to
be as follows:-
:-
In the class of azo colors deriving from benzidine and other paradiamines red
coloring matters have only been obtained in combining the said amines with naphtyl-
amines sulpho acids. These colors are more or less altered by acids. The com-
bination of paradiamines with naphtols or their sulpho acids, which resist to the action
of acids, yields but blue to violet colors. We have found a method to get brilliant
red coloring matters from naphtols and benzidine or its homologues.
In our English Patent 816% (Gaus and Hoffmann) we have mentioned a dye stuff
formed by the action of y naphtoldisulphonate upon tetrazodiphenyl-this body results
from the combination of only one molecule naphtol-sulphonic acid with one molecule
of benzidine, the second equivalent does not combine under ordinary circumstances.
This product combines very well with one equivalent of phenole. The thus obtained
compound has not yet been described, (though the general chemical law for its
formation has been formulated by Martins' (German Patent No. 40954). It shows
a violet shade in an alkaline solution. We have found that by alkylating or
benzylating, the said product is transformed into a beautiful scarlet dyestuff which has
the new and characteristic property to dye animal as well as vogetable fibres without
any mordant in acid-or neutral-or alkaline baths.
We proceed as follows:-
18.4 kilos of benzidine are diazotised and added to a cooled solution of 40 kilos of
naphtoly disulphonate of sodium; after a short time 10 kilos of phenole are
introduced, then heated to boiling and the coloring matter is precipitated by common
salt and separated by filtration. The precipitate is again dissolved in 200 liters of
water and 200 kilos of alcohol with 4.5 kilos of caustic soda and heated together with
12 kilos of ethylbromide during 24 hours in a closed vessel to about 60° C. After
cooling the new coloring matter separates in shining crystals.
Instead of benzidine other paradiamines, such as methylbenzidine, tolidine, instead
of y naphtol disulphonate, ẞ naphtol a monosulphonate and instead of phenole, cressol
may be employed with a similar result.
Dated this Sth day of August 1889.
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Production of New Red Coloring Matters.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, (a communication
to me from abroad by Leopold Cassella & Co., of Frankfort-on-Main, in the Empire
of Germany, Manufacturing Chemists,) do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
In the class of azo colors deriving from benzidine and other paradiamines red
coloring matters have only been obtained in combining the said amines with naphtyl-
amines sulpho acids. The combination of paradiamines with naphtols or their sulpho
acids yields but blue to violet colors. My correspondents have found a method to get
brilliant red coloring matters from naphtols and benzidine or its homologues.
D
7

page_text: In their English Patent No. 8168 (Gans and Hoffmann) is mentioned a dye stuff
formed by the action of y naphtoldisulphonate upon tetrazodiphenyl; this body results
from the combination of only one molecule naphtol sulphonic acid with one molecule
of benzidine, the second equivalent does not combine under ordinary circumstances.
This product combines very well with one equivalent of phenol. The thus obtained
compound has not yet been described. It shows a violet shade in an alkaline solution.
My correspondents have found that by alkylating or benzylating, the said product is
transformed into a beautiful scarlet dyestuff which has the new and characteristic
property to dye animal as well as vegetable fibres without any mordant in acid-or
neutral or alkaline baths.
It is preferred to proceed as follows:-
184 kilos of benzidine are diazotised and added to a cooled solution of 40 kilos of
ẞ naphtol y disulphonate of sodium; after a short time 10 kilos of phenol are intro-
duced, then heated to boiling and the coloring matter is precipitated by common salt
and separated by filtration. The precipitato is again dissolved in 200 litres of water
and 200 kilos of alcohol with 4-5 kilos of caustic soda and heated together with
12 kilos of ethylbromide during 24 hours in a closed vessel to about 60° C. After
cooling the new coloring matter separates in shining crystals.
Instead of benzidine other paradiamines, such as methylbenzidine, tolidine, instead
of naphtol disulphonate, ẞ naphtol a monosulphonate and instead of phenol cresol
may be employed with a similar result.
γ
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
1. The process substantially as described for the production of red coloring matters
by alkylating or benzylating the substances formed by the combination of one mole-
cule of naphtol a monosulphonate or y disulphonate and of one molecule of phenol
or cresol with one molecule of tetrazo-diphenyle or its homologues.
2. As new articles of manufacturo the red coloring matters obtained by the said
process.
Dated this 10th dow of Dearmbar 1800
CARPMAEL & Co.,
Agents.