Manufacture of Azo Coloring Matters Derived from Para- phenylenediamine.
Year: 1892

page_text: Date of Application, 2nd May, 1892
Complete Specification Left, 2nd Feb., 1893-Accepted, 25th Mar., 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by FARBWERKE VORMALS MEISTER LUCIUS and
BRUNING, of Hoechst a/ Main, Germany, Chemical Manufacturers.]
Manufacture of Azo Coloring Matters Derived from Para-
phenylenediamine.
I, OLIVER IMRAY 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:-
From amongst the diamines of the benzene series there was used up till the
present time for the manufacture of violet or blue azo coloring matters, only para-
phenylenediamine and those coloring matters derived from this body, that have
been used for dyeing and printing were all of them constructed after the type of
a tetrazo-coloring matter; they were of some importance as substantive coloring
matters in cotton-dyeing.
Their defective qualities, in particular their great want of permanency under the
influence of daylight, completely excluded them from being employed in wool
dyeing (vide Nietzki Ber. d. deutsch. chem. Gesell XVII, 344; 1352; P. Griess,
ibid. 608; Friedlaender, Fortschritte d. Theerfarben Industrie 1877-1887 p. 523
and German Letters Patent 42011 and 42814).
The coloring matters deriving from the assymetrically alkylised para-phenylene-
diamine with the exception of those deriving from the mono-phenylised para-
phenylenediamine (German Letters Patent 58688), are of no value for industrial
purposes, seeing that the shades produced by means thereof, on being exposed to
light, fade away in a very short time.
Azo-coloring matters deriving from the para-phenylene diamine, its homologues
and isomers, having the typical constitution of an amido-azo-coloring matter
NH,
C.H. N,
x(x designating an azo-coloring matter component) and containing
a free amido group, have by reason of their insignificant qualities remained
unnoticed hitherto and their production has not been undertaken.
The only coloring matters of this class that have become known, were produced
years ago by Nietzki (Ber. d. deutsch. chem. Gesellsch. XVIII p. 627) and by
Meldola (Ber. d. deutsch chem. Gesellsch XVIII p. 627) but these were red or
brown colors of no value. The general impression was that it was impossible to
derive from the para-phenylene-diamine coloring matters that could be employed
for wool dyeing.
In opposition to these facts, my foreign correspondents have discovered that
several of the coloring matters hitherto not produced belonging to this class, which
up to now had remained unnoticed, are of great value, by reason, that the dye
wool in acid bath in shades ranging from violet to blue and that in opposition to
all the other violet and blue azo coloring matters deriving from the para-phenylene-
diamine they are fast to light to such an extent that they can successfully compete
with all the other rosaniline violets and rosaniline-blues now known.
Moreover, they excel over these coloring matters by not rubbing off even in the
deepest shades, and by remaining in clear solution in the acidulated dye-bath,
whereas most of the rosaniline derivatives mentioned, discharge under these con-
ditions the color acids in resinous form, thus often causing the stuffs to be dyed to
become spotted.
As to clearness of shade they come very near to the said rosaniline-derivatives,
and they dye shades as uniform as the rosaniline-violets and much more so than

page_text: the rosaniline-blues; as to fastness in soaping and washing, the prominent ones
amongst them surpass the competing rosaniline derivatives.
On cotton they scarcely dye at all; they are therefore not substantive coloring
matters.
Such coloring matters having the qualities above set forth, in particular those
of pure violet or blue shades, are not to be obtained from all the usual coloring
matter components, but only from a few of them, in particular from the dioxy-
naphthaline, and the amido naphthole mono- and poly-sulphonic acids. The greatest
number of the other azo-coloring matter components, such for example as the
naphthole sulphonic acids and the phenols in general give shades of no value,
ranging from red to claret red or from yellow to red brown.
The most suitable method for the manufacture of these coloring matters is to
reduce the nitro-group in the corresponding nitro-coloring matters by means of
alkaline reducing-agents, such as for example: sulphides of alkalis, polysulphurets,
sulphide of hydrogen, in ammoniacal solution; with less success, by means of
stannous-oxide, zinc powder, glucose etc. etc.
Thus for example the coloring matter obtained from para-nitro-diazo-benzole and
a dioxynaphthaline disulphonic acid.

page_text: The manner in which the manufacture of the colouring matters is carried out is
described in the following examples :
1. REDUCTION OF THE NITRO-AZO-COLORING MATTERS INTO THE NOVEL
COLORING MATTERS.
The reduction proceeds very smoothly in neutral or alkaline solutions.
Example: The coloring matter derived from diazotised para-nitraniline and
dioxy-naphthaline disulphonic acid, which acid is obtained by melting the naphtho-
sultone disulphonic acid of the German Letters Patent 56,058 together with caustic
alkalies (the so called "Chromotrop acid ") is dissolved in the 15 to 20 fold
quantity of warm water, and while agitated, and at from 50 to 60° C it is mixed by
degrees with a solution of sulphide of sodium of 20 per cent. until a sample, on the
addition of a further quantity of sulphide of sodium and on being heated, no longer
becomes more blueish and on being acidulated still developes sulphide of hydrogen
after some time.
Experience soon enables the operator to recognise exactly the point of completion.
It has been found that a correct proportion of the nitro coloring matter prepared
from 138 parts of para nitraniline and 400 parts of dioxynaphthaline disulphonate
of sodium will constitute for example 2,500 parts of a sulphide of sodium solution
containing 450 parts of crystallised sulphide of sodium.
The reduction begins immediately on the addition of this solution and with
considerable heating, and is completed, at a temperature of from 60 to 70° C after
an hour at the most, and at a lower temperature after three hours at the most.
The solution of the novel coloring matter thus formed is neutralized with acetic
acid or with a diluted mineral acid. The colouring matter is obtained by precipita-
tion by means of common salt and is further treated in the usual manner.
2. MANUFACTURE OF THE NOVEL AZO COLORING MATTERS BY SAPONIFI-
CATION OF THE COLORING MATTERS FORMED FROM ACETO-DIAMINES.
Example: The coloring matter obtained from diazotised acetyl-para-phenylene-
diamine and amido-naphthol-sulphonic acid is dissolved in water to form a solution
of 10 per cent. and is mixed with a suitable quantity of caustic soda, for example :
the coloring matter formed from 150 parts of acetyl-phenylenediamine and 341 parts
of amido-naphthol sulphonic acid is mixed with 80 parts of caustic soda and while
it is kept agitated the mixture is boiled in an open vessel or heated under pressure
at 120 to 125° C until a sample on being supersaturated with acetic acid no longer
has its violet colour turned to blue and can be smoothly diazotised.
Under these conditions the saponification will be complete in from 2 to 6 hours.
When the saponification is complete, the mass is neutralised with acetic acid or
diluted mineral acid. A part of the colouring matter separates. The remainder
is precipitated by the addition of common salt and it is treated further in the usual
manner.
The saponification can also be effected by heating with sulphuric acid of about
30 per cent. and also, but with less success, by heating with water alone under
pressure.
The industrially most important of the new coloring matters are produced by the
reduction or by the saponification of those azo coloring matters that are obtained
in the usual manner from the following bases and components:

page_text: Mono aceto derivative of the toluylene diamine of the melting point 64° and its
isomers.
Mono-aceto derivative of the xylylene diamine of the melting point 104° and its
isomers and homologues etc.
COMPONENTS.
•
Dioxynapthaline mono sulphonic acid obtained from the alpha-naphthole
disulphonic acid S of the German Letters Patent 40,571 by melting it together
with caustic alkali;
Dioxynaphthaline disulphonic acid obtained from the alpha naphthol-trisulphonic
acid of the German Letters Patent 56,058 by melting it together with alkali;
Dioxynaphthaline disulphonic acid obtained from the alpha naphthole trisulphonic
acid S by melting with alkali. (This alph-naphthol trisulphonic acid S is obtained
by sulphonisation of the alpha-naphthol disulphonic acid S of the German Letters
Patent 40,571.)
Amido naphthol disulphonic acid obtained from the naphthylamine trisulphonic
acid described in the German Letters Patent 56,058 by melting it together with
alkali;
And the isomers, homologues and analogues of these acids.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of Azo Coloring Matters Derived from Para-
phenylenediamine,
I, OLIVER IMRAY, 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:-
From amongst the diamines of the benzene-series was used up to now for the
manufacture of violet or blue azo colouring matters the paraphenylenediamine alone
and those coloring matters deriving from this body, that have been used for dyeing
and printing were all of them constructed after the type of a tetrazo-coloring
matter and as substantive coloring matters arrived at some importance in cotton-
dyeing alone.
Their deficient qualities, for all their so pronounced instability under the influence
of day light, completely excluded them from being employed in wool dyeing (ride:
Nietzki Ber. d. deutsch. chem Gesell XVII, 344; 1352; P. Griess, ibid. 608;
Friedlaender, Fortschritte d. Theerfarben Industrie 1877-1887 p. 523 and German
Letters Patent 42011 and 42814).
The coloring matters deriving from the asymmetrically alkylised para-phenylene-
diamine excepted those deriving from the mono-phenylised paraphenylenediamine
(German Letters Patent 58688) are of no value for industrial purposes, seeing that
the shades produced by means of them, on being exposed to light fade away in
very short time.
Azo-colouring matters deriving from the para-phenylenediamine, its homologues
and isomeres, having the typical constitution of an amido-azo coloring matter
сон.
NH,
N
³. x (≈ designating an azo-coloring matter component) and containing a
free amido group, have by reason of their insignificant qualities remained unnoticed
hitherto and their production has not been aimed at.
The only coloring matters of this class that have become known, were produced
years ago by Nietzki (Ber. d. deutsch chem. Gesellsch. XVII p. 344) and by

page_text: Meldola (Ber. d. deutsch chem. Gesellsch. XVIII p. 627) but these were red or
brown colours of no value. The general impression was that it would be impossible
to derive from the paraphenylenediamine coloring matters that could be employed
for wool dyeing.
In opposition to these facts my foreign correspondents have discovered that
several of the coloring matters hitherto not produced belonging to this class, which
up to now had remained unnoticed, are of great value, by reason, that they dye wool
in acid bath shades ranging from violet to blue and that in opposition to all the
other violet and blue azo coloring matters deriving from the paraphenylenediamine,
they are fast to light to such an extent that they can successfully compete with all
the other rosaniline violets and rosaniline-blues now known.
Moreover they excel over these coloring matters by not rubbing off even in the
deepest shades and remaining in clear solution in the acidulated dye-bath, whereas
most of the rosaniline derivatives mentioned, under these conditions discharge the
coloring matter acids in resinous form, whereby the stuffs to be dyed are often
spotted.
As to clearness of shade they come very near to those rosaniline-derivatives and
they dye shades as uniform as the rosaniline-violets and much more so than the
rosaniline-blues; as to fastness in soaping and washing the prominent ones amongst
them surpass the competing rosaniline-derivatives.
On cotton they scarcely dye at all; they are not substantive coloring matters.
Coloring matters of the qualities preceedingly set forth, for all those of pure
violet or blue shades, are not to be obtained from all the usual coloring matter
components, but only from a few of them, so far all from the dioxy-napthaline and
the amido-naphthole mono- and poly- sulphonic acids. The greatest number of the
other azo-coloring matter components, such as for example; the naphthole sulphonic
acids and the phenols in general dye shades of no value, ranging from red to claret
red or from yellow to red brown.
The most suitable method for the manfacture of these coloring matters is to
reduce the nitro group in the corresponding nitro-coloring matters by means of
alkaline reducing-agents, such as for example: sulphides of alkalies, polysulphurets,
sulphide of hydrogen, in ammoniacal solution, with less success by means of stannous-
oxide, zinc-powder, glucose etc. etc.
•
For example the coloring matter obtained from para-nitro-diazo-benzole and a
dioxynaphthaline-disulphonic acid.
AT
When acid reducing agents are used the reaction will never proceed smoothly.
The identical coloring matters are obtained by saponification of the corresponding
acetyl-diamine coloring matters by boiling the same together with a moderately
strong alkali-lye or with diluted acids.
Thus for example the coloring matter obtained from para diazo-acetanilide and a
dioxynaphthaline-disulphonic acid.

page_text: When the amido-diazobenzole first described by Griess (Griess Ber. d. deutsch.
chem. Gesell XVII, 606, Nietzki Ber. d. deutsch. chem. Gesell XVII, 1252) is
caused to act upon the corresponding components the same coloring matters will be
obtained, though a very bad yield of the same and in very impure state.
The coloring matters thus obtained contain a free amido group, whereby is
bestowed upon them a strong basic character; with mineral acids they form solid
salts most of them colored tile red, by means of nitrous acids they can be converted
into diazo compounds, which combine with a further molecule of a combinable body
forming tetrazo-coloring matters of the type.
From these qualities and the fact that by the various methods mentioned are
obtained products that are identical results that the novel coloring matters have the
typical constitution C, H, {N and contain a free amido group.
N,-
The manner in which the manufacture of the coloring matters is carried out is
described in the following examples:
1) REDUCTION OF THE NITRO AZO COLORING MATTERS INTO THE NOVEL
COLORING MATTERS.
The reduction proceeds very smoothly in neutral or alkaline solutions.
Example: The coloring matter derived from diazotised para-nitraniline and
dioxy naphthalinedisulphonic acid, which acid is obtained by melting the naphtho-
sultone-disulphonic acid of the German Letters Patent 56,058 together with
caustic alkalies (the so called "Chromotrop acid") is dissolved in the 15-20 fold
quantity of warm water, and while agitated and at from 50 to 60° C. admixed by
portions with a solution of sulphide of sodium of 20 per cent., until a sample on the
addition of a further quantity of sulphide of sodium and on being heated does not
assume a bluer tint and on being acidulated still develops sulphide of hydrogen after
a time.
Experience soon enables the operator to recognise exactly the point of
completion.
It has been found that a correct proportion for the nitro coloring matter prepared
from 138 parts of paranitraniline and 400 parts of dioxynaphthaline disulphonate of
sodium would be for example 2,500 parts of a sulphide of sodium solution containing
450 parts of chrystallised sulphide of sodium.
The reduction immediately begins at the addition of this solution with consider-
able self heating and is complete at a temperature of from 60 to 70° C. after an hour
at the most and at a lower temperature after 3 hours at the most.
The solution of the novel coloring matter thus formed is neutralised with acetic
acid or with a diluted mineral acid. The coloring matter is obtained by precipita-
tion by means of common salt and further treated in the usual manner.
2) MANUFACTURE OF THE NOVEL AZO COLORING MATTERS BY SAPONIFI-
CATION OF THE COLORING MATTERS FORMED FROM ACETO-DIAMINES.
Example: The coloring matter obtained from diazotised acetyl-para-phenylene-
diamine and amido-naphthol-sulphonic acid is dissolved in water to form a solution
of 10 per cent. and mixed with a suitable quantity of caustic soda, for example: the
coloring matter formed from 150 parts of acetyl-phenylenediamine and 341 parts of
amido-naphtholsulphonic acid is mixed with 80 parts of caustic soda and while it is
kept agitated the mixture is boiled in an open vessel or heated under pressure at
120 to 125° C. until a sample on being super-saturated with acetic acid no
longer turns its violet colour to blue and can be smoothly diazotised.
Under these conditions the saponification will be complete in from 2 to 6 hours.

page_text: When the saponification is complete, the mass is neutralised with acetic acid or
diluted mineral acid. A part of the colouring matter separates by itself. The
remainder is precipitated by the addition of common salt and it is treated further
in the usual manner.
The saponification can also be made by heating with sulphuric acid of about
30 per cent., and also but with less success by heating with water alone under
pressure.
From amongst the bases and components from which are obtained in the usual
manner those coloring matters, that by reduction or by saponification form the
novel coloring matters most valuable for industrial purposes, are mentioned as
examples the following viz. :
COMPONENTS.
Dioxynaphthaline mono sulphonic acid obtained from the alpha-naphthole disul-
phonic acid S of the German Letters Patent 40571 by melting it together with
caustic alkali ;
Dioxynaphthaline disulphonic acid obtained from the alpha naphthole trisul-
phonic acid of the German Letters Patent 56058 by melting it together with
alkali;
Dioxynaphthaline disulphonic acid obtained from the alpha naphthole trisul-
phonic acid S by melting with alkali.
This alpha-naphthole trisulphonic acid S is obtained by sulphonisation of the
alpha naphthole disulphonic acid S of the German Letters Patent 40571.
Amido naphthole disulphonic acil obtained from the naphthylamine trisulphonic
acid described in the German Letters Patent 56058 by melting it together with
alkali.
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 herein described process for the manufacture of amido azo coloring
matters ranging in shades from violet to blue and applicable on wool, deriving from
the para phenylenediamine and its homologues;
a) By converting in the azo-coloring matters formed from nitro bases and
components the nitro group into the amido group by means of alkaline
reducing agents.
b) By eliminating the acetyl-group in the azo coloring matters formed from
acetyl bases and components, by boiling them together with diluted alkalies,
acids or with water under or without pressure.
2. The coloring matters manufactured as above set forth.
Dated this 2nd day of February 1893.
ADAT °
TMD AV
ABEL & IMDAY,
Agents for the Applicant.