Manufacture of 2:7 Amidonaphtholdisulpho Acid and of Colouring Matters Derived therefrom.
Year: 1893

page_text: Date of Application, 28th Aug., 1893
Complete Specification Left, 28th May, 1894-Accented, 14th July, 1894
[Communicated from abroad by THE ACTIEN GESELLSCHAFT FÜR ANILIN
FABRIKATION, of Berlin, in the Empire of Germany, Chemical Manufacturers.]
Manufacture of 2:7 Amidonaphtholdisulpho Acid and of Colouring
Matters Derived therefrom.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery
Lane, in the County of London, Chartered Patent Agent, do hereby declare the
nature of this invention to be as follows:-
The invention relates to the production of a new and valuable sulpho acid, which
is a derivative of 2: 7 dihydroxynaphthalene, and to the preparation of azo-colouring
matters by means of this acid.
I.
My foreign correspondents have discovered, that the 2: 7 dihydroxynaphthalene,
may be easily converted into a disulpho acid. According to the strength of the
sulphuric acid employed the sulphonation process may be carried out on the water
bath or at lower temperature.
The disulpho acid obtained may be isolated in the form of its acid soda salt,
which is very sparingly soluble in acidulated salt-solution. If the soda-salt of this
new dihydroxynaphthalene disulpho acid is heated with ammonia under pressure, a
new 2:7 amido-naphtholdisulpho acid is formed, which is sparingly soluble in
water.
11.
My foreign correspondents have further discovered, that the above mentioned
disulpho-acid may be employed for the production of new and valuable colouring
matters by combining it with diazo or tetrazo compounds.
For instance, by the combination of the new 2: 7 amidonaphthol disulpho acid
with the tetrazo derivatives of paradiamines, such as benzidine, tolidine, dianisidine
or analogous bodies, red to violet red substantive dyes are formed. The new
sulpho acid may also be employed for the preparation of so-called mixed tetrazo-
dyes; moreover the 2: 7 amido naphthol disulpho acid can be diazotised and the
diazo compound obtained may be combined with phenols, amines, amido phenols or
their sulpho and carbo acids.
Dated this 28th day of August 1893.
ABEL & IMRAT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of 2:7 Amidonaphtholdisulpho Acid and of Colouring
Matters Derived therefrom.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane,
in the County of London, Chartered Patent Agent, 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 :—
This invention relates to the manufacture of a new and valuable sulpho acid
which is a derivative of 2:7 amidonaphthol and to the preparation of azo-colouring
matters by means of this acid.

page_text: In order to produce this new amidonaphtholdisulpho acid my foreign corre-
spondents start from the 2:7 dihydroxynaphthaline disulpho acid, obtained by
sulphonation of 2:7 dihydroxynaphthaline. This sulphonation may be carried out
on the water-bath or at a lower temperature, according to the strength of the
sulphuric acid employed.
The dihydroxynaphthaline disulpho acid is very readily soluble in water and is
not precipitated by the addition of hydrochloric acid. The acid sodium salt is less
soluble in water, nearly insoluble in an acid salt solution, and insoluble in alcohol.
The alkaline solution shows a weak blue fluorescence and becomes blue on standing
some time in the open air. With ferric chloride it produces a blue solution.
When the soda-salt of this dihydroxynaphthaline disulpho acid is heated with
ammonia under pressure a new 2: 7 amidonaphthol disulpho acid is formed.
Example. 25 kilos. of the dihydroxynaphthalinedisulpho acid are heated with
75 kilos. of ammonia solution containing about 23 per cent. ammonia, at a tempera-
ture of about 180-220° C. for 14 hours.
The mixture is then dissolved in water, the excess of ammonia is removed by
boiling and the new acid is precipitated by means of hydrochloric acid.
This new acid is sparingly soluble in cold and hot water, the sodium salt is easily
soluble and shows a blue-green fluorescence. From the solution of the soda-salt
the free acid is precipitated by addition of mineral acids but not by acetic acid.
My foreign correspondents have further discovered that the said amidonaphthol-
disulpho acid may serve for the production of new and valuable colouring matters.
In the first place the new acid may be diazotised and combined with amines or
phenols to produce azo colouring-matters.
Also the amidonaphtholdisulpho acid yields dyestuffs when combined with diazo
or tetrazo bodies. The process for the production of the last mentioned groups
of colouring matters may be carried out in alkaline or in slightly acidulated solution;
the combination products produced in alkaline solution differ from those prepared
in slightly acid solution generally by more blueish tint.
For the preparation of such colouring-matters the following examples may be
given

page_text: for ning the intermediate product from benzidine and naphthol and then combining
this product with the 2: 7 amidonaphtholdisulpho acid.
The simple and mixed colouring matters obtained in a similar manner by the
combination of the 2: 7 amidonaphtholdisulpho acid with tetrazo bodies of para-
diamines (tolidine, dianisidine etc.) dye unmordanted cotton according to the diamine
or the second component employed red to brown, violet and blue tints.
These dyes are distinguished by their property of yielding by action of nitrous
acid new diazo bodies, which by subsequent combination with amines, phenols or
their sulpho- or carbo acids yield colouring matters, the tints of which vary generally
from brown to gray-black.
The production of these colouring matters may also be effected on the fibre.
For this purpose the fibre is dyed with the colouring matters above mentioned,
then is introduced into a slightly acidulated solution of sodium nitrite and finally
into suitable alkaline baths of amines, diamines, phenols, amido phenols of the
benzene or naphtaline series or sulphonic or carboxylic derivatives thereof.
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
1. The herein described process for the manufacture of a new 2: 7 amidonaphthol-
disulpho acid by the action of ammonia under pressure on the 2:7 dihydroxy-
naphthalinedisulpho acid.
2. The herein described process for the production of azo colouring-matters by
combining one molecule of the diazo body of the new acid with one molecule of an
amine, phenol, or their sulpho- or carbo-acids.
3. The herein described process for the production of azo-colouring matters by
combining one molecule of a tetrazo-compound with two molecules of the new acid."
4. The herein described process for the production of mixed azo colouring-
matters by combining one of the two di-azo groups of the tetrazo derivatives of
para diamines with the 2:7 amidonaphtholdisulpho acid and combining the other
diazo group with an amine or diamine, a phenol, an amido-phenol, or their sulpho-
and carbo-acids.
5. The herein described process for producing polyazo dye stuffs from the
colouring matters obtained by the processes set forth in the third and fourth claims,
by diazotising these products and combining them with one or two molecules of
amines, diamines, phenols, amidophenols or sulphonic- or carboxylic derivatives
thereof.
6. The process for producing on the fibre the polyazo dye stuffs referred to in the
preceding claim by dyeing the same with such colouring-matters as are obtained
as set forth in the third and fourth claims, introducing the fibre so dyed
into a moderately acidulated bath of sodium nitrite and then into suitable
alkaline or acidulated baths of amines, diamines, phenols, amido phenols or
sulphonic or carboxylic derivatives thereof.
7. The 27 amido naphthol disulpho acid manufactured as set forth in Claim 1.
8. The colouring matters manufactured as set forth in Claims 2, 3, 4 and 5.
ABEL & IMRAY,
Agents for the Applicant.