Improvements in the Manufacture and Production of New Azo-dyestuffs.
Year: 1894

page_text: Date of Application, 25th Jan., 1894
Complete Specification Left, 18th Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture and Production of New
Azo-dyestuffs.
I, GEORGE WILLIAM JOHNSON of 47 Lincoln's Inn Fields in the County of
London Patent Agent do hereby declare the nature of this invention (which has
been communicated to me from abroad by Kalle & Co. of Biebrich on Rhine in
the Empire of Germany, Manufacturers) to be as follows:-
By treating the 1.5 naphthalene disulphonic acid with strong fuming sulphuric
acid at a low temperature, naphthalene trisulphonic acid is obtained which by
nitrating and subsequently reducing is converted into the alpha naphthylamine-tri
sulphuric acid 1. 4. 6. 8. The diazo compound thereof when boiled with diluted
acids yields a 1.8 naphtsulton 4.6 disulphonic acid, which by melting with caustic
alkalies forms the 1.8 dioxynaphthalene-4.6-disulphonic acid. The sodium salt
of the latter crystallizes in white prismatic needles and is readily soluble in water.
The solution showing a feeble bluish violet lustre becomes by addition of ferric
chloride of an intensively bluish green coloration, which disappears on heating.
The 1.8 dioxynaphthalene-4.6-disulphonic acid is susceptible of being combined
with one or two diazo groups.
In the following description the production of dyestuffs is given resulting from
the combination of one molecule of 1.8 dioxynaphthalene-4.6-disulphonic acid
with one molecule of the diazo compound of a monamine or an amido-azo-compound
respectively but I do not limit myself to the precise details. These dyestuffs yield
shades tending more towards blue than the corresponding chromotropes; they
differ from the colouring-matters obtained by using 1.8 dioxynaphthalene-
disulphonic acid S, forming, like the chromotropes, on the fibre very valuable lakes,
the shades of which differ from the original tints.
The new colouring matters are produced in the usual manner by combination in
a weak acid or in an alkaline solution.
The parts are by weight.

page_text: The amido-azo-compound, obtained in the usual way by combining the diazo 20
derivative of 32-6 parts of a-naphthylamine disulphonic acid III with 10.3 parts of
a-naphthylamine is diazotized with 26 parts of concentrated bydrochloric acid and
7.2 parts of nitrite and the separated diazo compound is brought together with an
acetic acid solution of 37 parts of 1.8 dioxynaphthalene 4.6 disulphonic-acid. After
some hours the mass is heated to 40-50 degrees Centigrade and maintained at that 25
temperature until the formation of the dyestuff is finished.

page_text: By replacing the alpha-naphthylamine by the alpha-naphthylamine-sulphonic-
acid 1.6 or 1.7 dyestuffs result, having a more reddish tint, whereas amidonaphthols
yield dyestuffs of a more bluish green shade.
Dated the 25th day of January 1894.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture and Production of New
Azo-dyestuffs.
I GEORGE WILLIAM JOHNSON of 47 Lincoln's Inn Fields in the County of
London Patent Agent do hereby declare the nature of this invention (which has
been communicated to me from abroad by Kalle & Co. of Biebrich on Rhine in
the Empire of Germany Manufacturers) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
By treating the 1.5 naphthalene disulphonic acid with strong fuming sulphuric
acid at a low temperature naphthalene-trisulphonic acid is obtained which by
nitrating and subsequently reducing is converted into the alpha-naphthylamine
trisulphonic acid 1. 4. 6. 8. The diazo compound thereof when boiled with diluted
acids yields a 1.8 naphtsulton 4.6 disulphonic acid, which by melting with caustic
alkalies form the 1.8 dioxynaphthalene 4.6 disulphonic acid. The sodium salt of
the latter crystallizes in white prismatic needles and is readily soluble in water.
The solution shewing a feeble bluish violet lustre becomes by addition of ferric
chloride of an intensely bluish-green colouration, which disappears on heating.
The 1.8 dioxynaphthalene 4.6 disulphonic acid is susceptible of being. combined
with one or two diazo groups.

page_text: In the following description the production of dyestuffs is given resulting from
the combination of one molecule of 1.8 dioxynaphthalene 4.6 disulphonic acid with
one molecule of the diazo compound of a monamine or an amido-azo-compound
respectively but I do not limit myself to the precise details. These dyestuffs yield
shades tending more towards blue than the corresponding chromotropes; they
differ from the colouring matters obtained by using 1.8 dioxynaphthalene-
disulphonic acid S, forming, like the chromotropes, on the fibre very valuable
lakes, the shades of which differ from the original tints.
The new colouring matters are produced in the usual manner by combination in
a weak acid or in an alkaline solution.
The

page_text: EXAMPLE 2.
The amido azo compound obtained in the usual way by combining the diazo
derivative of 32-6 parts of a-naphthylamine disulphonic acid III with 14.3 parts of
a-naphthylamine is diazotised with 26 parts of concentrated hydrochloric acid and
7.2 parts of nitrite and the separated diazo compound is brought together with an
acetic acid solution of 37 parts of 1.8 dioxynaphthalene 4.6 disulphonic acid.
After some hours the mass is heated to 40-50 degrees Centigrade and maintained
at that temperature until the formation of the dyestuff is finished.
The shades of some colours produced in an analogous manner are described in
the following table.
By replacing the alpha-naphthylamine by the alpha-naphthylamine-sulphonic-
acid 1.6 or 1.7 dyestuffs result, having a more reddish tint, whereas amidonaphthols
yield dyestuffs of a more bluish green shade.
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 I
claim is.-
The production of new azo dyestuffs resulting from the combination of one
equivalent of 1.8 dioxynaphthalene-4.6-di-sulpho-acid with one equivalent of the
diazo compound of a monamine or with one equivalent of the diazo compound of
an amido-azo-compound substantially as herein before described.
JOHNSONS & WILLCOX,
47, Lincoln's lon Fields, Agents.