Manufacture of Substantive Azo-dyestuffs derived from Para-phenylenediamine.
Year: 1899

page_text: Manufacture of Substantive Azo-dyestuffs derived from
Para-phenylenediamine.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals; Meister
Lucius & Brüning, of Hoeclist a/Main, in the Empire of Germany, Chemical
Manufacturers,) to be as follows:-
If chrysoidine of the constitution para-ainidobenzene-sulphonic acid azo-meta-
diamine he treated with 1 molecular proportion of nitrous acid, the amido-groups of
the metadiamine are at first not attacked, but only those of the benzene nucleus
containing the sulphonic group, and well characterised monodiazo-compounds, soluble
with difficulty, are obtained; they are mostly of a green tint.
My foreign correspondents have found that valuable dyestuffs may be obtained
from these diazo-compounds containing sulphonic groups by combining them with
substances capable of combination, dyestuffs which contain para-phenylenediamine-
sulphonic acid in middle position and having the properties of powerfully dyeing
unmordanted cotton in an alkaline bath.
The tints thus obtained may all be developed with diazo-compounds, such as,
nitrodiazobenzene, tetrazodiphenyl and the like, whereby a greater depth of colour
and fastness are obtained. Though the second component in the dyestuff molecule
be capable of combining with 2 molecules of the diazo-compound, yet greater
intensity is obtained when the dye is developed on the fibre.
The process for producing such dyestuffs is illustrated by the following examples:
3-29 kilos. of para-amidobenzene-ortho-sulphonic acid azo-meta-phenylenediamine
(Na salt) are dissolved together with 0.69 kilos. of sodium nitrite in about 150 litres
of water and the solution, cooled down to 10° C., is slowly run into 150 litres of cold
dilute hydrochloric acid, containing 0-80 kilos. H.Cl, while the mixture is well
stirred.
After stirring for some time at a low temperature, the diazo-compound is run into,
a cold solution of 1.13 kilos. of meta-phenylenediamine in 50 litres of water. The
free acid of the desired tetrazo-dyestuff is formed at once as a blackish precipitate.
Then a solution of 1.65 kilos. of sodium carbonate in 20 litres of water is slowly
run in and heated to about 60° C., when the dyestuff partly dissolves with a violet
colour; it is isolated in the usual manner.

page_text: The dyestuff dyes unmordanted cotton brown-violet; on being subsequently treated
on the fibre with diazo-compounds, full brown tints thoroughly fast to washing are
obtained;
EXAMPLE HI
The diazo-compound: obtained as set forth in Example I from 3.29 kilos. of 5
para-amidobenzene-ortho-sulphonic acid azo-meta-phenylenediamine (Na salt) is run
into a solution of 2.7 kilos. of sodium amidonaphtholsulphonate R and 2 kilos. of
sodium carbonate in 50 litres of water, while the mixture is stirred. A dark blue-
violet tetrazo-body is formed, which, mostly remains insoluble when cold.
It is then heated for some time to 50° to 60° C. and the dyestuff is isolated in the 1
usual manner. '.
:
The dyestuff directly dyes cotton black-violet. When treated on the fibre with
dinzotised para-nitraniline a deep black of remarkable fastness is obtained.
The following table contains a number of such dyestuffs showing the direct shades
on cotton as well as the shades of those subsequently treated with diazotised para-
nitraniline,

page_text: Manufacture of Substantive Azo-dyestuffs derived from
Para-phenylenediamine.
1, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals: Meister
Lucius & Brüning, of Hoechst a/Main, in the Empire of Germany, Chemical
Manufacturers) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
If chrysoidine of the constitution para-amidobenzene-sulphonic acid azo-meta-
diamine be treated with 1 molecular proportion of nitrous acid, the amido-groups of
the meta-diamine are at first not attacked, but only those of the benzene nucleus
containing the sulphonic group, and well characterised monodiazo-compounds, soluble
with difficulty, are obtained; they are mostly of a green tint.
My foreign correspondents have found that valuable dyestuffs may be obtained
from these diazo-compounds containing sulphonic groups by combining them with
substances capable of combination, dyestuffs which contain para-phenylenediamine-
sulphonic acid in middle position and having the properties of powerfully dyeing.
unmordanted cotton in an alkaline bath.
The tints thus obtained may all be developed with diazo-compounds, such as,
nitrodiazobenzene, tetrazodiphenyl and the like, whereby a greater depth of colour
and fastness are obtained. Though the second component in the dyestuff molecule
be capable of combining with 2 molecules of the diazo-compound, yet greater
intensity is obtained when the dye is developed on the fibre.
The process for producing such dyestuffs is illustrated by the following examples.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The herein described manufacture of violet to blue-black azo-dyestuffs yielding
when developed on the fibre fast brown to black tints, by converting monoazo
compounds having the general form of para-amidobenzene-sulphonic acid-azo-meta-
diamine into diazo-compounds having the general form of para-diazo-benzene-
sulphonic acid-azo-meta-diamine and by combining these latter with amines or
phenols or their sulphonic or carboxylic acids or with such azodyestuffs as are capable
of being combined.
2. The dyestuffs manufactured as above set forth.