Improvements in the Production of Azo Colours.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Production of Azo Colours.
1, THOMAS RICHARD SHILLITO of 89 Chancery Lane, London, W.C., Engineer
and Patent Agent, do hereby declare the nature of this invention, a communication
to me from abroad by Messieurs John Rudolph Geigy & Co., of Basle, Switzerland,
Colour Manufacturers, to be as follows:-
This invention relates to the production of new azo colours derived from
p-diamidoditolylamine and p-diamidophenyltolylamine. These paradiamines have
not hitherto been used for the preparation of azo colouring matters.
The production of the named bases may be carried out by reduction of the
corresponding indamines. In this manner p-diamidoditolylamine is produced by
reduction, for example with powder of zinc and hydrochloric acid, of that indamine
which, in the well known manuer, is produced by oxydising p-toluylendiamine
together with o-toluidine; p-diamidophenyltolylamine results by reducing the
indamine obtained by oxydation of p-phenylenediamine with o-toluidine or of
p-toluylenediamine with aniline.
For the preparation of symmetrical diazo dye stuffs deriving from the above
named p-diamines the following substances are particularly useful:-
B₁a, amidonaphtol B, sulpho acid and its alkylated or phenylated derivatives.
Ba, amidonaphtol 3, 6, disulpho acid.
Ba, amidonaphtol B, sulpho acid, the known mono and disulpho acids of
a, a amidonaphtol and of a, a, amidonaphtol.
n, a dioxynaphtalene a sulpho acid.
a a dioxynaphtalene ß: ẞ, disulpho acid.
B, a, dioxynaphtalene ß, carbon ẞ, sulpho acid.
EXAMPLE 1.
30 kilos. of hydrochlorate of p-diamidoditolylamine are diazotised in about
500 liters of water at 0° Celsius with 40 kilos. of hydrochloric acid of 21° Bé.
and 14 kilos. of nitrite of sodium. The yellowish coloured diazo solution thus
obtained is pressed into an alkaline solution of 64 kilos. of a a amidonaphtol
B. B. disulpho acid. As the colouring matter still contains zinc salt resulting
from the reduction of the indamine, it is precipitated by acidulating with
bydrochloric acid, then filtered off and washed out. It is then dissolved in hot
water by addition of soda, precipitated with common salt, filtered off and dried.
It dyes unmordanted cotton in blue shades.
For the production of mixed disazo dye stuffs there are used the above named
sulpho acids and besides them m-phenylenediamine and m-toluylenediamine.
EXAMPLE 2.
The diazo compound formed with 30 kilos. of hydrochlorate of p-diamido-
ditolylamine, as described in Example 1, is added to a solution of 20 kilos.
of carbonate of sodium, then a solution of 26 kilos. of B a amidonaphtol
B, sulphonate of sodium is added. The intermediary compound yields as a dark
brown precipitate. The mass is then mixed with a solution of 12 kilos. of

page_text: stirring some hours, poured into an alkaline solution of 22 kilos. of m-phenylene-
diamine and the colouring matter filtered off and uried. It dyes unmordanted
cotton in deep black shades.
EXAMPLE D.
The intermediary and further diazotised compound, prepared according to
Example C, is alkalised with an excess of carbonate of sodium, then added first to
an alkaline solution of 24 kilos. of B, a, amidonaphtol ẞ, sulpho acid and then to a
solution of. 12 kilos. of m-toluylene diamine. The colouring matter thus formed
dyes unmordanted cotton in blueish black shades.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is :-
1. The production of symmetrical disazo dye stuff's by combination of the tetrazo
compounds of p-diamidoditolylamine or of p-diamidophenyltolylamine with two
molecules of one of the sulpho acids cited hereinabove under Part I, substantially
as described. . .
2. The production of mixed disazo dye stuffs by combination of the same tetrazo
compounds with one molecule of the said sulpho acids, and then with one molecule
of another of these sulpho acids, or with one molecule of one of the other
substances cited hereinabove under Part II, substantially as described.
3. The production of trisazo colours by combination of the further diazotised
-intermediary compounds from one molecule of the named bases and one molecule
- of the sulpho acids, named hereinabove under Part III, with two molecules of a
metadiamine, or by combination of the said further diazotised intermediary
compounds first with one molecule of one of the sulpho acids cited hereinabove
under Part I and then with one molecule of a metadiamine, substantially as
described.
4. As new compounds the azo colouring matters referred to in the preceding
claims 1 to 3 inclusive substantially as described.
Dated this 8th day of May 1897
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C.