The Manufacture and Production of Poly-azo-dyes of the Benzidine and analogous Series.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
The Manufacture and Production of Poly-azo-dyes of the Benzidine
and analogous Series.
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 Anilin and Soda Fabrik of
Ludwigshafen on Rhine in the Empire of Germany) to be as follows:-
In the Specification of Letters Patent No. 6697 of April 1st 1895 the conversion
of colouring matters of the aniline series into corresponding azo-dyes of the
benzidine series is described. The process consists in suitably treating mono azo
dyes with an oxidizing agent whereby the molecules of the mono-azo dye become
coupled together in pairs.
The azo dyes there used are mono-azo-dres and represented by the scheme
where X signifies a second azo-dye component and B, which I will hereinafter
refer to as the "oxidizable radical" the residue of aniline or certain other amido
compounds. As instances of oxidizing agents which can be used, pyrolusite,
manganese peroxide, ammonium persulphate and lead superoxide have been
mentioned but the invention is not restricted to the use of these particular
agents.
Now my foreign correspondents have discovered that the new process can also
be applied to dis- and poly-azo-dyes containing such an oxidizable radical" (B)
such as the following
1. Secondary dis-azo-dyes of the scheme

page_text: 4. The dis-azo-dyes derived from m-phenylene-diamine as first component. The
poly-azo-dyes or compounds of the benzidine series obtained from the before
mentioned dis- and poly-azo-compounds (by coupling together two molecules
according to the said new process) differ from them by showing in the most cases
darker shades and possessing affinity (or increased affinity) to the unmordanted
cotton-fibre.
In accordance with the invention described in the aforesaid Specification
No. 6697 of 1895 the process is not confined to the application of two molecules of
the same azo-compound but is also applicable to mixtures of two different azo-
compounds containing an "oxidizable radical" thus mixtures of equal molecules.
of a mono-azo-dye used in the aforesaid Specification No. 6697 of 1895 and of one
of the above mentioned dis- or poly-azo-compounds, or of two of the latter ones
can be used.
* Dated this 25th day of June 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
или
тописноп от гогу-адо-у от the benzidine
and analogous Series.
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
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 :-
In the Specification of Letters Patent No. 6697 of April 1st 1895 the conversion
of colouring matters of the aniline series into corresponding azo dyes of the
benzidine series is described. The process consists in suitably treating mono-azo
dyes with an oxidizing agent whereby the molecules of the mono-azo-dye become
coupled together in pairs. The azo dyes there described as being used are mono-
azo-dyes and represented by the scheme
where X signifies a second azo dye component and B (which I will hereinafter
refer to as the "oxidizable radicle") the residue of aniline or certain other amido
compounds. As instances of oxidizing agents which can be used pyrolusite,.
manganese peroxide, ammonium persulphate and lead superoxide are mentioned but
the invention is not restricted to the use of these particular agents.
.

page_text: Now my foreign correspondents have discovered that the new process can also
be applied to dis- and poly-azo-dyes containing such an "oxidizable radicle " (B)
such as the following.
(1.) Secondary dis-azo-dyes of the scheme
(4.) Die-azo-dyes derived from meta phenylene-diamine as first component.
The poly-azo-dyes or compounds of the benzidine series, obtained from the before
mentioned dis- and poly-azo-compounds (by coupling together two molecules
according to the said new process) differ from them by shewing in the most cases
darker shades and possessing affinity (or increased affinity) to the unmordanted
cotton-fibre. Some of them can also be used for dyeing wool.
The process according to this invention is not confined to the application of two
molecules of the same azo-compound but is also applicable to mixtures of two
different azo-compounds containing an "oxidizable radicle" thus mixtures of equal
molecular proportions of a mono azo dye used as described in the aforesaid
Specification No. 6697 of 1895 and of one of the above mentioned dis- or poly-azo
compounds, or of two of the latter can be used.
The following example will serve to further illustrate the nature of the invention
and also the manner in which it can be carried into practical effect but the
invention is not confined to the conditions described under this example as they
are susceptible of great variation. The parts are by weight.
Take an azo body of one of the types herein before defined, say for instance,
amido-azo benzene-azo-beta-naphthol-disulpho acid, and mix ten parts thereof with
about one hundred and fifty parts of concentrated sulphuric acid at a temperature
five degrees below zero Centigrade.
Stir continuously whilst keeping cold and add about three parts of manganese
peroxide (containing about eighty per cent. MnO2).
The sulphuric acid solution of the initial dye is yellowish-red and as the reaction
proceeds, this changes to violet. When the change is complete, pour the melt
onto ice, to which a little sodium bisulphite has been added to destroy any excess
of manganese peroxide.
Collect the precipitated dye by filtration, wash, and press, and convert into the
sodium salt. Purify if necessary by redissolving.
The colouring matter so obtained dyes red shades on unmordanted cotton.
The following table contains further instances of azo-bodies of the types herein-
before defined which can be treated in accordance with this invention.
These

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 of symmetrical azo dyes by subjecting a dis- or poly-azo-
dye such as is herein before defined under 1, 2, 3 and 4 to oxidation by means of
manganese peroxide in sulphuric acid solution.
2. The manufacture of mixed azo-dyes by subjecting equal molecular proportions
of two of the dis- or poly-azo dyes such as are hereinbefore defined under 1, 2, 3
and 4 or a mixture of one such dis- or poly-azo-dye with a mono-azo-dye containing
an oxidizable radicle as hereinbefore defined, to oxidation by means of manganese
peroxide in sulphuric acid solution.
3. The manufacture of azo colouring matters from the initial materials
specifically mentioned in the foregoing table, substantially in the manner herein-
before described.
Dated thin 17th dow of Wahmin 1906
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.