Production of a Diamido Dioxynaphtalene and Dyeings therefrom.
Year: 1899

page_text: Date of Application, 5th May, 1899
PROVISIONAL SPECIFICATION.
The Production of a Diamido Dioxynaphtalene and Dyeings therefrom.
I, ROBERT BOLTON RANSFORD, of 41, Waldegrave Road, Upper Norwood, in
the County of Surrey, Gentleman, do hereby declare the nature of this invention
(which has been communicated to me from abroad by Leopold Cassella & Com-
pany, of Frankfort-on-Main, in the Empire of Germany) to be as follows:-
―:
My correspondents have discovered that a hitherto unknown diamido dioxy-
naphtalene (probably 1.8 diamido 2.7 dioxynaphtalene) possesses the property,
if combined with chrome mordants, of producing on wool a black of great in-
tensity which is fast to washing and milling.
If the almost colourless salts are brought together in a boiling bath with wool
previously mordanted with chrome, the same will gradually be dyed a deep blue
black, which fact renders this body of great technical value. For its production
it is preferable to start from the primary disazo derivatives of 2.7 dioxynaphta-
lene subjecting the same to the action of reducing agents. In order to easily
recover the regenerated component it is preferable to use the difficultly soluble
amido acids as for instance naphtionic acid, for the combination with the dioxy-
naphtatene; as the salts of the diamido dioxynaphtalene, especially the chlorhydrate
are comparatively easily soluble it is then not difficult to ceparate the products
of the reduction from each other.
Example: 160 kilograms 2.7 dioxynaphtalene are dissolved in water with
80 kilograms caustic soda; to this solution 400 kilograms soda are first added
and then at a temperature of 0° C. the diazo compound from 450 kilograms
naphtionic acid. The mixture is left standing for 24 hours and then the tem-
perature is gradually raised to 50° C. and the resulting disazo dyestuff precipitated
with common salt.
The dyestuff thus obtained is dissolved in 2000 litres boiling water, 150 kilo-
grams zinc dust are then added and about 500 kilograms muriatic acid are
allowed to run in gradually whilst well stirring; finally the solution has a
distinct acid reaction. The solution becomes discoloured, the naphtionic acid
separating out. The latter is filtered off and from the filtrate the rather diffi-
cultly soluble sulphate of the diamido dioxynaphtalene is precipitated with sul-
phuric acid in the shape of fine yellowish white needles, which dissolve in alkalis
with a magnificent blue colour.
The Production of a Diamido Dioxynaphtalene and Dyeings therefrom.
I, ROBERT BOLTON RANSFORD, of 41, Waldegrave Road, Upper Norwood, in
the County of Surrey, Gentleman, do hereby declare the nature of this invention
[Price Sd.

page_text: (which has been communicated to me from abroad by Leopold Cassella & Com-
pany, of Frankfort-on-Main, in the Empire of Germany,) and in what manner
the same is to be, performed to be particularly described and ascertained in and
by the following statement:-
My correspondents have discovered that a hitherto unknown diamido dioxy-
napltalene (probably 1.8 diamido 2.7 dioxynaphtalene) possesses the property,
if combined with chrome mordants, of producing on wool a black of great in-
tensity which is fast to washing and milling.
If the almost colourless salts are brought together in a boiling bath with wool
previously mordanted with chrome, the same will gradually be dyed a deep blue
black, which fact renders this body of great technical value. For its production
it is preferable to start from the primary disazo derivatives of 2.7 dioxynaphta-
lene subjecting the same to the action of reducing agents. In order to easily
recover the regenerated component it is preferable to use the difficultly soluble
amido acids as for instance naphtionic acid, for the combination with the dioxy-
naphtalene; as the salts of the diamido dioxynaphtalene, especially the chlorhydrate,
are comparatively easily soluble it is then not difficult to separate the products
of the reduction from each other.
Example: 160 kilograms 2.7 dioxynaphtalene are dissolved in water with
80 kilograms caustic soda; to this solution 400 kilograms soda are first added
and then at a temperature of 0° C. the diazo compound from 450 kilograms
naphtionic acid. The mixture is left standing for 24 hours and then the tem-
perature is gradually raised to 50° C. and the resulting disazo dyestuff precipitated
with common salt.
The dyestuff thus obtained is dissolved in 2000 litres boiling water, 150 kilo-
grams zinc dust are then added and about 500 kilograms muriatic acid are
allowed to run in gradually whilst well stirring; finally the solution has a
distinct acid reaction. The solution becomes discoloured, the naphtionic acid
separating out. The latter is filtered off and from the filtrate the rather difti-
cultly soluble sulphate of the diamido dioxynaphtalene is precipitated with sul-
phuric acid in the shape of fine yellowish white needles, which dissolve in alkalis
with a magnificent blue colour.
The method of dyeing black shades with the new compound may be illustrated
by the following example:
100 kilos. wool are boiled in a bath containing 10 kilos. of bisulphate of soda,
to which 5 kilos. bichromate of soda and 3 kilos. diamidodioxynaphtalene are
gradually added. The bath will be exhausted in about one hour.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what
I claim is:-
1. The production of the diamido dioxynaphtalene herein before described
by treating primary disazodyestuffs derived from 2.7 dioxynaphtalene with re-
ducing agents, substantially as described.
2. As a new article of manufacture the diamido dioxynaphtalene, hereinbefore
described.
3. The dyeings produced by combining the diamido dioxynaphtalene herein-
before described with chrome mordants.
Dated this 31st day of January 1900