An Improved Manufacture of Compounds for Dyeing, Consisting of a Mixture of Nitrite with Basic Amidoazo Compounds, or with the Nitro Compounds of Aromatic Monamines in the Form of a Paste, and the Application of such Paste for Diazotizing.
Year: 1889

page_text: Date of Application, 29th July, 1889
Complete Specification Left, 24th Apr., 1590-Accepted, 24th May, 1890
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBWERKE VORMALS MEISTER LUCIUS AND
BRUNING, of Hoechst-am-Maine, in the Empire of Germany, a Company carrying
on business as Chemical Manufacturers.]
An Improved Manufacture of Compounds for Dyeing, Consisting of
a Mixture of Nitrite with Basic Amidoazo Compounds, or with
the Nitro Compounds of Aromatic Monamines in the Form of a
Paste, and the Application of such Paste for Diazotizing.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the County
of London, Fellow of the Institute of Patent Agents, do hereby declare the nature of
this invention to be as follows:-
It is well known that of late certain azo colouring matters have been produced
successfully directly on the cotton fibre. There also exist already several patents
covering certain modes for the production of azo colouring matters on the fibre. In
general, the mode of proceeding consists in that one of the components, mostly the
one not to be diazotised, is first fixed on the fibre. The other component, the one that
has to furnish the diazo compound, has to be diazotised by the dyer; now this
is a rather difficult operation for the greater number of dyers, seeing that not all
the bases are quite easily diazotised and that mostly, in each case the diazotising
must be carried out under different conditions, and if these conditions are not well
known to the dyer, or he neglects to observe the same, the shades produced will
suffer or be different from those desired.
My correspondents have discovered a mode of proceeding which will enable the
dyer to effect readily the diazotization of those bases which, like amidoazobenzol,
amidoazotoluol, amidoazoxylol, meta and paranitraniline, metanitroparatoluidine, are
difficult to diazotize and require special modes of procedure, and to a large number of
dyers this process will be the only means by which they can produce the desired
result. By this improved method the proceeding is largely simplified and the manner
of diazotizing is rendered exactly the same for all the bases enumerated, which is of
great importance when having to produce mixed colours.
The said mode of rendering possible or facilitating the production by the dyer of
azo colouring matters on the fibre by means of the bases named consists in that there
are supplied to him the free bases in the form of pastes, in admixture with the
calculated quantity of nitrite. In order to produce the diazotisation there is nothing
more to do than to cause this paste to flow into a small excess of acid, whereupon the
diazo solution will be produced.
As an example I will take amidoazobenzol. The exact diazotisation of this body is
a rather difficult operation, even for the chemist who has not frequent occasion of
performing such operations. The complete diazotisation of the body depends on the
temperature at which it is carried out, on the quantity of acid used, and on the quality
of the material. The body is first to be dissolved by heating it with a large quantity
of acid, then it is diazotised at a fixed temperature and afterwards the excess of acid
has to be neutralised; these are operations to conduct which with exactness will
be rather difficult for most dyers, besides the expenditure of time caused thereby.
According to the present mode of procedure, the dyer has nothing more to do than
to cause the paste supplied by my correspondents (a mixture of the pure amidoazobenzol
base with the calculated quantity of nitrite) to flow into a small excess of dilute
hydrochloric acid and he will bave a solution of the diazo compound.
In exactly the same manner he will proceed for diazotizing, for example, nitraniline,
using the product supplied by my correspondents.

page_text: The great advantage to the dyer is this, that he can work all the bases enumerated
in exactly the same way.
Another advantage is that the bases can be diazotized not only each separately, but
also that mixtures of them may be treated in the same way. Thus for example the
chlorhydrate of amidoazobenzole requires for its diazotization a temperature at which
the diazo metanitroaniline is decomposed, and therefore a mixture of these two bodies
can be diazotized and certain shades resulting from such mixture can be produced
directly on the fibre only in the way discovered by my correspondents, that is to
say, by causing a mixture of the two pastes to flow into diluted acid in which it will
dissolve instantaneously, forming a clear diazo solution.
Dated this 29th day of July 1889.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Manufacture of Compounds for Dyeing, Consisting of
a Mixture of Nitrite with Basic Amidoazo Compounds, or with
the Nitro Compounds of Aromatic Monamines in the Form of a
Paste, and the Application of such Paste for Diazotizing.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the County
of London, Fellow of the Institute of Patent Agents, 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:
It is well known that of late certain azo colouring matters have been produced
successfully directly on the cotton fibre. There also exist already several Patents covering
certain modes for the production of azo colouring matters on the fibre. In general,
the mode of proceeding consists in that one of the components, mostly the one not to
be diazotised, first fixed on the fibre. The other component, the one that has to
furnish the diazo compound, has to be diazotised by the dyer; now this is a rather
difficult operation for the greater number of dyers, seeing that not all the bases are
quite easily diazotised and that mostly, in each case the diazotising must be carried
out under different conditions, and if these conditions are not well known to the dyer,
or he neglects to observe the same, the shades produced will suffer or be different from
those desired.
"My correspondents have discovered a mode of proceeding which will enable the
dyer to effect readily the diazotization of these bases which, like amidoazobenzol,
amidoazotoluol, amidoazoxylol, meta and paranitraniline, metanitroparatoluidine, are
difficult to diazotize and require special modes of procedure, and to a large number of
dyers this process will be the only means by which they can produce the desired
result. By this improved method the proceeding is largely simplified and the manner
of diazotizing is rendered exactly the same for all the bases enumerated, which is of
great importance when baving to produce mixed colours.
The said mode of rendering possible or facilitating the production by the dyer
of azo colouring matters on the fibre by means of the bases named consists in that
there are supplied to him the free bases in the form of pastes, in admixture with the
calculated quantity of nitrite. In order to produce the diazotization there is nothing
more to do than to cause this paste to flow into a small excess of acid, whereupon the
diazo solution will be produced.
As an example I will take amidoazobenzol. The exact diazotisation of this body is
a rather difficult operation, even for the chemist who has not frequent occasion of
performing such operations. The complete diazotisation of the body depends on the
temperature at which it is carried out, on the quantity of acid used, and on the quality
of the material. The body is first to be dissolved by heating it with a large quantity
of acid, then it is diazotised at a fixed temperature, and afterwards the excess of acid

page_text: has to be neutralised; these are operations to conduct which with exactness will be
rather difficult for most dyers, besides the expenditure of time caused thereby.
According to the present mode of procedure, the dyer has nothing more to do than
to cause the paste supplied by my correspondents (a mixture of the pure amidoazo-
benzol base with the calculated quantity of nitrite) to flow into a small excess of
dilute hydrochloric acid and he will have a solution of the diazo compound. In
exactly the same manner he will proceed for diazotizing, for example, nitraniline,
using the product supplied by my correspondents.
The great advantage to the dyer is this, that he can work all the bases enumerated
in exactly the same way.
Another advantage is that the bases can be diazotised not only each separately, but
also that mixtures of them may be treated in the same way. Thus for example the
chlorhydrate of amidoazobenzole requires for its diazotisation a temperature at which
the diazo metanitroaniline is decomposed, and therefore a mixture of these two bodies
can be diazotized and certain shades resulting from such mixture can be produced
directly on the fibre only in the way discovered by my correspondents, that is to say,
by causing a mixture of the two pastes to flow into diluted acid in which it will
dissolve instantaneously, forming a clear diazo solution.
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 :-
The production of a mixture of nitrite (1 molecule) with (1 molecule) amidoazo-
benzol, amidoazotoluol, amidoazoxylol, metanitraniline para-nitraniline or metanitro-
paratoluidine in form of a paste, and its use for diazotizing purposes.
Dated this 17th day of April 1890.
ABEL & IMRAY,
Agents for the Applicant.