The Manufacture and Production of Colouring Matters from Dinitro Naphthalenes.
Year: 1896

page_text: Date of Application, 12th Sept., 1896
Complete Specification Left, 22nd Feb., 1897-Accepted, 10th Apr., 1897
PROVISIONAL SPECIFICATION.
The Manufacture and Production of Colouring Matters from Dinitro
Naphthalenes.
I, BENJAMIN WILLCOX 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 The Badische Anilin & Soda Fabrik of
Ludwigshafen-on-Rbine in the Empire of Germany) to be as follows:-
In the Specification of the application for Letters Patent No. 7766 of 1896 the
production of violet-blue colouring matters from 1.1' dinitro-naphthaleno is
described.
My foreign correspondents have now discovered that if, instead of 1.1 dinitro-
naphthalene the isomeric 1.4' body be reduced in the presence of an alkaline sulphite,
or bisulphite there is obtained a new brown colouring matter which dyes wool from
the acid bath.
My foreign correspondents have further found that if a mixture of 1.1' and 1.4'
dinitro-naphthalene be treated in a similar manner a valuable violet-black to black
colouring matter of similar properties is obtained.
My foreign correspondents have further found that if instead of treating the
dinitro-naphthalene, or the mixture of dinitro-naphthalenes, simultaneously with
the reducing agent and a sulphite or bisulphite, the reaction can be effected by
treating the dinitro-naphthalene or the mixture of dinitro-naphthalenes first with one
of the reagents and then with the other.
As reducing agents in carrying out this invention grape-sugar, milk-sugar,
sodium sulphide, sodium stannite, zinc dust and the like can all be used.
The following examples will serve to further illustrate the nature of the invention
but it is not confined to the details given in these examples.
The parts are by weight.
EXAMPLE 1.
PRODUCTION OF A NEW BROWN COLOURING-MATTER.
Mix together about two hundred parts of 1.4¹ dinitro-naphthalene (preferably
finely divided in paste form) with about eight hundred parts of water and about
two hundred parts of grape sugar, five hundred and twenty parts of caustic soda lye
(containing about twenty-four per cent. NaOH) and about five hundred and fifty
parts of a forty per cent. solution of sodium bisulphite. Heat this mixture on the
boiling water bath until the dinitro-naphthalene is dissolved, or nearly so.
dilute it with about ten thousand parts of hot water and filter to separate any
unchanged dinitro-naphthalene. Acidify the filtrate with about seven hundred parts
Then
bont thinker toe non sont roal HCD boil for about

page_text: and four hundred parts of caustic soda lye (containing about twenty-four per cent.
NaOH). To this mixture add about two hundred parts of mixed dinitro-naphthalene
consisting of about one hundred and sixty parts of 1.1' and forty parts of 1.4' dinitro
naphthalene. Heat the mixture slowly to about seventy-five degrees Centigrade and
maintain this temperature for about five hours, then add about eight hundred parts
of hydrochloric acid (containing about thirty-two per cent. real HCI) and precipitate
the colouring matter by means of two hundred parts of common salt, stir for about
three days then filter and dry. If in the above example the proportion of the
1.4 dinitro-naphthalene used be materially increased the colouring matter is of a
more brownish shade.
EXAMPLE 3.
TREATMENT OF A DINITRO-NAPHTHALENE FIRST WITH A BISULPHITE AND THEN WITH
A REDUCING AGENT.
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, one
bundred 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
(Na2S+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.
Datod this 12th day of September 180€
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
The Manufacture and Production of Colouring Matters from Dinitro
Naphthalenes."
I, BENJAMIN WILLCOX, of 47 Lincoln's Inn Fields, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Badische Anilin & Soda Fabrik, of
Ludwigshafen-on-Rhine, in the Empire of Germany) and in what manner the same
is to he performed to be particularly described and ascertained in and by the following
statement:-
In the Specification of the application for Letters Patent No. 7766 of 1896 the
production of violet-blue colouring-matters from 1.1' dinitro-naphthalene is
described.
My foreign correspondents have now discovered that if, instead of 1.1' dinitro-
naphthalene, the isomeric 1.4' body be reduced in the presence of an alkaline sulphite
or bisulphite there is obtained a new brown colouring-matter which dyes wool from
the acid bath.
My foreign correspondents have further found that if a mixture of 1.1' dinitro-
naphthalene and 1.4 dinitro-naphthalene, be treated in a similar manner a valuable
violet-black to black colouring-matter of similar properties is obtained.
The dinitro-naphthalene or the mixture of dinitro-naphthalenes may be treated
either simultaneously or successively with the reducing agent and the sulphite or
bisulphite without changing the nature of the processes or of the products obtained.

page_text: The following examples will serve to further illustrate the nature of the invention,
and the manner in which it is to be performed, but it is not confined to the details
given in these examples. The parts are by weight.
EXAMPLE 1.
PRODUCTION OF A NEW BROWN COLOURING-MATTER.
Mix together about two hundred parts of 1.41 dinitro-naphthalene (preferably
finely divided in paste-form) with about eight hundred parts of water and about two
hundred parts of grape-sugar, five hundred and twenty parts of caustic soda lye
(containing about twenty-four per cent. NaOH) and about five hundred and fifty
parts of a forty per cent. solution of sodium bisulphite. Heat this mixture on the
boiling water-bath until the dinitro-naphthalene is dissolved or nearly so. Then dilute
it with about ten thousand parts of hot water and filter to separate any unchanged
dinitro-naphthalene. Acidify the filtrate with about seven hundred parts of hydro-
chloric acid (containing about thirty-two per cent. real HCI) boil for about half an hour
and then allow to cool. The colouring-matter separates out as a blackish-brown
powder. Filter and dry.
EXAMPLE 2.
PRODUCTION OF A VIOLET-BLACK TO BLACK COLOURING-MATTER.
Mix together about two hundred parts of grape-sugar, seven hundred and fifty parts
of water, four hundred parts of a forty per cent. solution of sodium bisulphite and four
hundred parts of caustic soda lye (containing about twenty-four per cent. NaOH).
To this mixture add about two hundred parts of mixed dinitro-naphthalene consisting
of about one hundred and sixty parts of 1.1' and forty parts of 1.1' dinitro-
naphthalene. Heat the mixture slowly to about seventy-five degrees Centigrade and
maintain this temperature for about five hours; then add about eight hundred parts
of hydrochloric acid (containing about thirty per cent. real HCI) and precipitate the
colouring-matter by means of two hundred parts of common salt, stir for about three
days then filter and dry. If in the above example the proportion of the 1.4' dinitro-
naphthalene used be inaterially increased the colouring-matter is of a more brownish
shade.
TREATMENT OF 1.4' DINITRO-NAPHTHALENE OR A MIXTURE THEREOF WITH 1.11
DINITRO-NAPHTHALENE FIRST WITH A SULPHITE OR BI-SULPHITE AND THEN
WITH A REDUCING AGENT.
Add about one hundred parts of finely divided 1.4' dinitro-naphthalene
to a mixture of five hundred parts of a forty per cent. solution of sodium bisulphite,
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 of sodium sulphide
(Na2S9 aq.) and stir the mixture at a temperature of ninety-five degrees
Centigrade for about two hours. Then add about four hundred parts of hydrochloric
acid (containing about thirty per cent. HCI). Precipitate by means of common salt
or potassium chloride, and alcohol, and collect the brown colouring-matter in the
usual way.
If a mixture of 1.11 dinitro-naphthalene and 1.4' dinitro-naphthalene be treated in
the manner described in the last preceding example in place of the 1.4' dinitro-
naphthalene alone a violet-black to black colouring-matter is obtained like that
obtained by proceeding according to the foregoing example 2.

page_text: 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 and production of new colouring-matter by treating the 1.41
dinitro-naphthalene with a reducing agent and with an alkaline sulphite or bi-sulphite
either simultaneously or one after the other.
2. The manufacture and production of new colouring matter by treating a mixture
of 1.1 and 1.4' dinitro-naphthalene with a reducing agent and with an alkaline
sulphite or bisulphite, either simultaneously or one after the other.
3. As new articles of manufacture colouring-matters such as can be obtained
substantially as hereinbefore described.
4. The manufacture of new colouring-matters in the manners herein before described
in the examples.
Dated this 22nd day of February 1897
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.