The Manufacture and Production of New Colouring-matter from Dinitro-naphthalene.
Year: 1896

page_text: Date of Application, 13th Apr., 1896
Complete Specification Left, 11th Feb., 1897-Accepted, 13th Mar., 1897
PROVISIONAL SPECIFICATION.
The Manufacture and Production of New Colouring-matter from
Dinitro-naphthalene.
1, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields, in the County of London,
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me by The Badische Anilin & Soda Fabrik of Ludwigshafen-
on-Rhine in the Empire of Germany) to be as follows:-
In the Specification of Letters Patent No. 10996 of 1893, granted to me, on a
communication from my present foreign correspondents, there is described the
production of a violet product possessing a metallic lustre and termed dye A.
This body is produced by the reduction of dinitro-naphthalene with grape-sugar
and is insoluble in nearly all the ordinary solvents. It can only be used in
dyeing by production on the fibre, and yields on cotton in this way violet-black to
black shades.
My foreign correspondents have found that if a dinitro-naphthalene be reduced
in the presence of a sulphite, or bisulphite, a different product results, viz. :-
a dyestuff which is completely soluble in water, and which dyes from the acid bath,
unmordanted wool, deep violet-blue shades.
The following example will serve to further illustrate the nature of the invention,
but the invention is not confined to this example.
PRODUCTION OF A
EXAMPLE.
COLOURING-MATTER
SOLUBLE VIOLET-BLUE
1.1 DINITRO-NAPHTHALENE.
FROM
Mix together about ten parts (the parts are by weight) of finely powdered
1.1 dinitro-naphthalene, about eight hundred parts of water, about ten parts of
grape-sugar, about twenty parts of sodium-bisulphite solution, containing about
forty per cent. NaHSO, and about twenty parts of caustic soda lye containing
about twenty four per cent. NaOH. Heat this mixture, at about eighty degrees
Centigrade, until no unchanged dinitro-naphthalene can be found in the reaction
product. This usually requires about two hours heating. The solution is of a
beautiful blue colour. Add about thirty parts of hydrochloric acid (containing
about thirty-two per cent. HCl) and boil until no further evolution of sulphurous
anhydride takes place. Precipitate the dye which can be done by means of
common salt, or potassium chloride, filter, press and dry. In appearance the
product so obtained is a violet-black powder, with metallic lustre, soluble in cold
water, giving a violet coloured solution.
Dated this 13th day of April 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.

page_text: The Manufacture and Production of New Colouring-matter from
Dinitro-naphthalene.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Badische Auilin & Soda Fabrik of
Ludwigshafen-on-Rhine 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 :-
In the Specification of Letters Patent No. 10996 of 1893 granted to me, on a
communication from my present foreign correspondents there is described the
production of a violet product possessing a metallic lustre and termed dye A.
This body is produced by the reduction of dinitro-naphthalene with grape-sugar
and is insoluble in nearly all the ordinary solvents. It can only be used in dyeing
by production on the fibre and yields on cotton in this way violet black to black
shades.
My foreign correspondents have found that if a dinitro-naphthalene be reduced
in the presence of a sulphite or bisulphite a different product results, viz. :-
a dyestuff which is completely soluble in water, aud which dyes from the acid bath
unmordanted wool deep violet-blue shades. Grape-sugar, milk sugar, sodium
sulphide, sodium stannite, zinc-dust and the like are suitable reducing agents for
the above purpose.
The following example will serve to further illustrate the nature of the
invention and the manner in which it can be carried into practical effect but the
invention is not confined to the details of this example. The parts are by
weight.
PRODUCTION OF A
EXAMPLE.
VIOLET-BLUE
COLOURING-MATTER
SOLUBLE
1.1 DINITRO-NAPHTHALENE.
FROM
Mix together about ten parts of finely powdered 1.1' dinitro-naphthalene, about
eight hundred parts of water, about ten parts of grape-sugar, about twenty parts
of sodium bisulphite solution containing about forty per cent. NaHSO, and about
twenty parts of caustic soda lye containing about twenty four per cent. NaOH.
Heat this mixture at about eighty degrees Centigrade until no unchanged dinitro-
naphthalene can be found in the reaction product. This usually requires about
two hours heating. The solution is of a beautiful blue colour. Add about thirty
parts of hydrochloric acid (containing about thirty-two per cent. HCI.) and boil
until no further evolution of sulphurous anhydride takes place. Precipitate the
dye which can be done by mears of common salt, or potassium chloride, filter,
press and dry. In appearance the product so obtained is a violet-black powder
with metallic lustre, soluble in cold water, giving a violet coloured solution.
If desired the treatment with the reducing agent and with the sulphite or
bisulphite can be effected successively instead of simultaneously without changing
the nature of the process or of the product obtained. The following is a variation
of the example for such successive treatment.
Add about one hundred parts of finely divided 1.1' dinitro-naphthalene to a
mixture of five hundred parts of a forty per cent. solution of sodium bisulphite,

page_text: one hundred and fifty parts of caustic soda lye (containing about twenty four
per cent. NaOH) and about one thousand parts of water; boil till the dinitro-
naphthalene is dissolved. Next add about one hundred and fifty parts sodium
sulphide (Na,S+ 9 aq) and stir the mixture at a temperature of ninety five degrees
Centigrade until it assumes a beautiful deep blue colour.. Then add about four
hundred parts of hydrochloric acid (containing about thirty per cent. HCI).
Precipitate the colouring matter by means of common salt, or potassium chloride,
and alcohol, and collect in the usual way.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is.
1. The manufacture of new soluble colouring matter by treating 1.11 dinitro-
naphthalene with a reducing agent and with a solution of a sulphite or a
bisulphite.
2. As a new article of manufacture colouring matter such as can be obtained.
substantially as hereinbefore described.
3. The manufacture of a new colouring matter in the manners herein before
described in the example.
Dated this 11th day of February 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents..