Improvements relating to the Manufacture of Dihydroxy-naphtha- lene-sulphoacids and of corresponding Azo-dyes.
Year: 1893

page_text: Date of Application, 9th Oct., 1893
Complete Specification Left, 9th July, 1894-Accepted, 18th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture of Dihydroxy-naphtha-
lene-sulphoacids and of corresponding Azo-dyes.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields, in the County of Middlesex
Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by The Badische Anilin and Soda Fabrik of
Ludwigshafen-on-Rhine in the Empire of Germany) to be as follows :-
:―
This invention relates to the manufacture of sulpho-acids of dihydroxy-naphthalene
and of corresponding azo-dyes, which in part are new bodies and in part have
already been produced by other processes.
The said sulpho acids are obtained according to this invention by treating the
corresponding amido-naphthol-sulpho acids hereinafter mentioned, in the caustic
alkaline melt; but if this melting operation be not conducted under certain special
conditions, which my foreign correspondents have discovered, no useful product is
obtained. Similarly the corresponding azo-dyes are obtained according to this
invention by melting the azo-dyes derived from the said amido-naphthol-sulpho-acids
with a caustic alkali.
The following are the sulpho acids to which this invention can be applied.
(1) The 11 amido-naphthol-mono-sulpho acid described in the Specification of
Letters Patent No. 9676 of 1890 granted to me.
(2) The 111 amido-naphthol-disulpho acid described in the Specification of
German Patent No. 62289 granted to my foreign correspondents.
The azo-dyes which can be used in carrying out this invention are those derived
from the above mentioned sulpho acids.
The following examples will serve to illustrate the nature of the invention but
the invention is not limited thereto. The parts are by weight.
EXAMPLE 1.
PREPARATION OF 11 DIHYDROXY-NAPHTHALENE SULPHO ACID.
Mix about thirty parts of 11' amido-naphthol-mono-sulpho acid with a solution
of about twenty parts of caustic soda and two hundred and sixty parts of water and
heat the mixture in an autoclave. Maintain the internal temperature at about two
hundred and thirty degrees centigrade for about thirty six hours. The operation
may be considered at an end when no amido-naphthol-sulpho-acid can be recognized
in the melt by adding hydrochloric acid to a test portion thereof. Acidify the
product with hydrochloric acid and precipitate the dihydroxy-naphthalene-sulpho-
acid as potassium salt by adding solid potassium chloride. Recrystallize from
potassium chloride solution and dry.
This sulpho-acid appears to be identical with that described in the Specification of
the German Patent No. 67829.

page_text: sodium acetate and then a little solution of diazo-benzene-chloride; pour a portion
of the dye, thus formed, onto filter paper and treat it with a drop of soda solution,
if the colour change to yellow in a manner characteristic of the dihydroxy-
naphthalene disulpho-acid, then no more amido-naphthol-sulpho acid is present and
the operation may be interrupted. In order to obtain the dihydroxy-naphthalene-
disulpho-acid in the pure state, acidify the melt with hydrochloric acid and
concentrate the resulting solution on the water bath until it solidifies to a crystalline
paste. Filter, press and dissolve the press cakes in boiling alcohol (90 per cent.
C,H,OH) on cooling the acid is obtained in the form of needle-like crystals.
The acid appears to be identical with the so-called 1·1' dihydroxy-naphthalene
disulpho acid S.
The strength of the caustic soda lye used in the above examples can be varied to
a certain extent thus a ten per cent. solution may be used or on the other hand a
weaker solution than that described may be used. The temperature may be
increased to 250 degrees centigrade without changing the nature of the reaction
but above two hundred and seventy degrees decomposition takes place even with
dilute lye just as with strong lyes it occurs at a lower temperature.
PREPARATION OF AN AZO-DYE DERIVED FROM 1·1' DIHYDROXY-NAPHTHALENE-
MONO-SULPHO ACID.
First prepare diazo-benzene-sulpho-acid in the usual way taking about twenty
parts of crystallized sodium sulphanilate, about thirty parts of hydrochloric acid
(containing about 30 per cent. real acid HCI) and about seven parts of sodium
nitrite. Run the diazo compound into about two thousand four hundred parts of
water containing about twenty four parts of the hereinbefore mentioned 1.1 amido-
naphthol-mono-sulpho acid dissolved, or suspended, in it. Stir till, on boiling, a
test-portion no evolution of nitrogen can be noticed. Boil and to the boiling
solution add one fifth its volume of saturated salt solution and allow to cool. The
dye separates out in the crystalline form; filter press and dry. Mix the dye so
obtained with about six times its weight of caustic soda lye (containing about
35 per cent. NaOH) and heat the mixture to about one hundred and twenty or
one hundred and thirty degrees centigrade either in an open vessel, or in an
autoclave. The operation may be discontinued when test portions of the melt give
solutions in water of a permanent yellowish-red colour and not bluish-red as at the
beginning of the operation. Then pour the melt into an excess of dilute sulphuric
acid containing about twenty five per cent. of H,SO, boil and precipitate the dye
with common salt. Allow to cool, collect the dye on the filter, press and dry.
EXAMPLE 4.

page_text: Improvements relating to the Manufacture of Dihydroxy-naphtha-
lene-sulphoacids and of corresponding Azo-dyes.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by The Badische Anilin and 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 :-
This invention relates to the manufacture of sulpho acids of dihydroxy-naphtha-
lene and of corresponding azo-dies.
The said sulphoacids are obtained according to this invention by treating the
corresponding amido naphthol-sulpho acids hereinafter mentioned, in the caustic
alkaline melt; but if this melting operation be not conducted under certain special
conditions which my foreign correspondents have discovered no useful product is
obtained. Similarly the corresponding azo dyes are obtained according to this
invention by melting the azo-dyes derived from the said amido-naphthol-sulpho-
acids with a caustic alkali.
The following are the sulphoacids to which this invention can be applied:
(1) The 11 amido naphthol-mono-sulpho acid described in the Specification of
Letters Patent No. 9676 of 1890 granted to me.
(2) The 11 amido-naphthol-disulphoacid described in the Specification of
German Patent No. 62289 granted to my foreign correspondents.
The azo dyes which can be used in carrying out this invention are those derived
from the above mentioned sulphoacids.
The following examples will serve to illustrate the nature of the invention and
the manner in which it can be carried into practical effect, but the invention is not
limited to the examples. The parts are by weight.
EXAMPLE 1.
PREPARATION OF 1·11 DIHYDROXY-NAPHTHALENE-SULPHOACID.

page_text: acid. The end of the operation can in this case be ascertained by the following
test. Acidify a sample of the melt with acetic acid and add also an excess of
sodium acetate and then a little solution of diazo-benzene chloride; pour a portion
of the dye thus formed onto filter paper and treat it with a drop of soda solution,
if the colour change to yellow in a manner characteristic of the dihydroxy-
naphthalene disulpho acid then no more amido-naphthol sulphoacid is present and
the operation may be interrupted.
In order to obtain the dihydroxy-naphthalene-disulphoacid in the pure state,
acidify the melt with hydrochloric acid and concentrate the resulting solution on
the water-bath until it solidifies to a crystalline paste. Filter, press and dissolve
the press cakes in boiling alcohol (90 per cent. C,H,OH); on cooling, the acid
is obtained in the form of needle-like crystals.
The acid appears to be identical with the so called 11 dibydroxy-naphthalene
disulphoacid S.
The strength of the caustic soda-lye used in the above examples can be varied
to a certain extent thus a ten per cent. solution may be used or on the other hand a
weaker solution than that described may be used. The temperature may be
increased to two hundred and fifty degrees centigrade without changing the nature
of the reaction but above two hundred and seventy degrees decomposition takes
place even with dilute lye just as with strong lyes it occurs at a lower temperature.
EXAMPLE 3.
PREPARATION OF AN AZO-DYE DERIVED FROM 11' DIHYDROXY-NAPHTHALENE_
MONO-SULPHO-ACID.
}
First prepare diazo-benzene-sulpho acid in the usual way taking about twenty
parts of crystallized sodium sulphanilate, about thirty parts of hydrochloric acid
(containing about thirty per cent. real acid HCI) and about seven parts of sodium
nitrite. Run the diazo-compound into about two thousand four hundred parts of
water containing about twenty four parts of the hereinbefore mentioned 1.1 amido-
naphthol-mono-sulpho acid dissolved or suspended in it. Stir till, on boiling a test
portion, no evolution of nitrogen is noticeable. Boil, and to the boiling solution
add one fifth its volume of saturated salt solution and allow to cool. The dye
separates out in the crystalline form; filter, press and dry. Mix the dye so obtained
with six times its weight of caustic soda lye or thereabout containing about
35 per cent. NaOH) and heat the mixture to, or about to, one hundred and twenty,
or one hundred and thirty, degrees centigrade either in an open vessel, or in an
autoclave. The operation may be discontinued when test portions of the melt give
solutions in water of a permanent yellowish-red colour, and not bluish-red, as at the
beginning of the operation. Then pour the melt into an excess of dilute sulphuric
acid containing about twenty five per cent. of H,SO, boil and precipitate the dye
with common salt. Allow to cool, collect the dye on the filter press and dry.
EXAMPLE 4.
PREPARATION OF AN AZO-DYE DERIVED FROM 1·1' DIHYDROXY-NAPHTHALENE
DISULPHO ACID.
Mix one part of the azo-dye from diazo benzene and the hereinbefore mentioned 1.11
amido-naphthol disulpho acid with three parts or thereabout of caustic potash to
which one fifth or thereabout its weight of water has been added, and heat to, or
about to, one hundred and fifty degrees centigrade. The end of the reaction is
ascertained by taking tests from time to time and dissolving in water.
When the
colour of successive solutions is the same, the operation may be discontinued.
Dissolve the melt in water, acidify with sulphuric acid, boil, precipitate the dye
with common salt, collect and dry in the usual way.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. The manufacture of a 1·1' dihydroxy-naphthalene sulpho acid by heating
the 11' amido-naphthol-mono-sulpho acid herein before mentioned with a solution
of caustic soda the concentration of the solution and the temperatures employed
being as hereinbefore defined.
2. The manufacture of a 1·11 dihydroxy-naphthalene disulpho acid by heating
the 11 amido naphthol-disulpho acid hereinbefore mentioned with a solution of
caustic soda the concentration of the solution and the temperatures employed being
as hereinbefore defined.
3. The manufacture of the azo dyes of the 1·11 dihydroxy naphthalene-mono-
sulphoacid herein before mentioned by heating the azo-dyes of the corre-
sponding 11 amido naphthol-mono-sulphoacid with caustic soda lye substantially
as hereinbefore defined.
4. The manufacture of the azo dyes of the 1'11 dihydroxynaphthalene-disulpho
acid hereinbefore mentioned by treating the azo-dyes of the corresponding 1.11
amido-naphthol-disulpho acid with caustic potash substantially as hereinbefore
described.
5. The manufacture of dihydroxy-naphthalene sulpho acids and of azo dyes
derived therefrom in the manners hereinbefore described under the several
examples.
A
1
T1
1004
JOHNSONS & WILLCOX,
Agents.