Production of Mixed Disazo Dyestuffs from Delta-amido- naphtol.
Year: 1894

page_text: Date of Application, 17th Nov., 1894
Complete Specification Left, 15th Aug., 1895-Accepted, 21st Sept., 1895
PROVISIONAL SPECIFICATION.
The Production of Mixed Disazo Dyestuffs from Delta-amido-
naphtol.
1, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, (a communi-
cation to me from abroad by Leopold Cassella & Co. of 18 Liebigstrasse,
Frankfort-on-Main, in the Empire of Germany, Manufacturing Chemists,) do
bereby declare the nature of this invention to be as follows:-
The 8-amidonaphtol described in the German Patent No. 69458 combines
easily with the tetrazo derivatives of the paradiamines forming dyestuffs which are
absolutely insoluble in water and vary in shade from blue to black. If however
one of the diazo groups of such tetrazo derivatives is combined with components
which give easily soluble azo derivatives as especially those of the disulpho acids
of the amidonaphtols and dioxynaphtalenes and the other diazo group is combined
with 8-amidonaphtol, blue to blue black dyestuffs are obtained which owing to
the presence of -amidonaphtol show a remarkable fastness to light and washing.
Example. 244 kilos. dianisidine are tetrazotised and quickly mixed with a
solution of 32 kilos. a, a, dioxynaphtalene ẞ, ẞ, disulpho acid kept alkaline by
means of carbonate of soda. To the intermediate body thus formed an aqueous
solution of 16 kilos. 8-amidonaphtol dissolved in 4 kilos. caustic soda is added.
The dyestuff forms at once. It separates from the solution completely, when
common salt is added. It dyes unmordanted cotton a greenish dark blue of great
fastness to light and washing.
In an analogous manner similar combinations are produced as for instance, the
following dyestuffs
Con OT SIDE ART
[Price 8d.]
SYDNEY PITT.

page_text: COMPLETE SPECIFICATION.
The Production of Mixed Disazo Dyestuffs from Delta-amido-
naphtol.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, (a communi
cation to me from abroad by Leopold Cassella & Co., of 19 Liebigstrasse,
Frankfort-on-Main, in the Empire of Germany, Manufacturing Chemists), do
hereby declare the nature of this invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
The S-amidonaphtol described in the German Patent No. 69458 combines easily
with the tetrazo derivatives of the paradiamines forming dyestuffs which are
absolutely insoluble in water and vary in shade from blue to black. If however
one of the diazo groups of such tetrazo derivatives is combined with components
which give easily soluble azo derivatives as especially those of the disulpho acids
of the amidonaphtols and dioxynaphtalenes and the other diazo group is combined
with amidonaphtol, blue to blue black dyestuffs are obtained which owing to the
presence of amidonaphtol show a remarkable fastness to light and washing.
Example. 244 kilos. dianisidine are tetrazotised and quickly mixed with a
solution of 32 kilos. a₁ a dioxynaphtalene B2 B3 disulpho acid kept alkaline by
means of carbonate of soda. To the intermediate body thus formed an aqueous
solution of 16 kilos. & amidonaphtol dissolved in 4 kilos. caustic soda is added.
The dyestuff forms at once. It separates from the solution completely, when
common salt is added. It dyes unmordanted cotton a greenish dark blue of great
fastness to light and washing.
In an analogous manner similar combinations are produced as for instance, the
following dyestuffs
1 molecule a a4 amidonaphtol B2 B3 disulpho acid and 1 molecule
&amidonaphtol
-
dark blue
1 molecule a₁ a amidonaphtol ẞ₁ a disulpho acid and I'molecule
8 amidonaphtol
1 molecule a, a, dioxynaphtalene ß₁ a disulpho‘acid and 1 'molecule'
8 amidonaphtol
pure blue
blue
If instead of dianisidine another paradiamine, as for instance tolidine, is used,
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amidonaphtol B, ẞ, disulpho acid produces a blackish blue
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a, a, dioxynaputalene B, B
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reddish blue black
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B₁ az
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Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed 1 declare that what
I claim is -
1. The process of producing blue dyestuffs by combining one molecule of a
tetrazo compound (such as for instance tetrazoditolyle, tetrazodiphenolether) with

page_text: one molecule of the 8 amidonaphtol described in the German Patent No. 69458
and one molecule of an amidonaphtoldisulpho acid or a dioxynaphtalenedisulpho
acid (such as for instance a, a, amidonaphtol B, a, disulpho acid; a, a dioxy-
naphtalene B2B, disulpho acid) substantially as described.
2. The new dyestuffs above described.