The Production of New Azo Dyes, Applicable for Dyeing and Printing.
Year: 1889

page_text: Date of Application, 12th Feb., 1889
Complete Specification Left, 4th Nov., 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
The Production of New Azo Dyes, Applicable for Dyeing and
Printing.
I, OTTO NICHOLAS WITT, of 33 Lindenallée, Westend, Charlottenburg, in the
Empire of Germany, Ph. D., F.C.S., do hereby declare the nature of this invention to
be as follows:-
My invention is based upon the new and unexpected discovery that the rule,
according to which orthodioxy derivatives of aromatic hydrocarbons do not yield azo
derivatives if acted upon with diazo compounds, is not applicable to Alpha-Beta-
orthodioxynaphtalene, a. substance, which is more commonly known under the name
of Beta-naphtohydro quinone. If diazo compounds be made to act on a cold aqueous
solution of this compound, azo dyes are invariably produced, in the same manner as
by the reaction of such diazo compounds upon any other oxy- or dioxynaphtalene.
The azo dyes produced in this. manner from Betanaphtohydroquinone are however
distinguished from almost all other azo dyes by one property, which makes them
particularly valuable and useful for dyeing and printing. This important property
consists in their ability to combine and form insoluble lakes with the metallic oxides
of the iron group, such as alumina, ferric and chromic oxide. These new azo dyes
may therefore be dyed, the same as alizarine or logwood, on mordanted fibres, on
which they produce useful shades of considerable depth and fastness, superior to the
majority of those produced with the azo dyes, which have hitherto been in use.
This useful property of combining with the mordants of the iron group is common
to all my new azo dyes produced from Betanaphtohydroquinone. But it depends
upon the choice of the diazo compound combined with the Betanaphtohydroquinone,.
whether the azo dye produced is better suited for dyeing and printing on mordanted
cotton or on mordanted wool or silk. If the chloride or any other salt of a non-
sulphonated aromatic diazo compound be allowed to act upon Betanaphtohydroquinone,
an azo dye is produced which is very sparingly soluble in water. The azo dyes of
this class are particularly useful for dyeing and printing cotton. If, on the other
hand, the sulpho derivatives of aromatic diazo compounds be made to react upon the
said Betanaphtohydroquinone, then are azo-dyes produced which are very soluble in
water and particularly adapted for dyeing and printing wool and silk.
I shall now proceed to describe the exact process which I prefer for producing
both cotton and wool dyes from Betanaphtohydroquinone.
To produce, for instance, a cotton dye, I first prepare a solution of diazo benzene
cbloride by mixing together, at a temperature not exceeding 5° C., 93 parts of aniline
with 200 parts of hydrochloric acid (containing 37 per cent. of anhydrous acid) and
2000 parts of water; and by adding gradually a cold aqueous solution of sodic nitrite,
containing 69 parts of this salt. This solution of diazobenzene chloride I allow to
run into a cold aqueous solution previously prepared by dissolving 160 parts by
weight of Betanaphtohydroquinone and 150 parts of crystallized sodic acetate in
2000 parts of water. A dark orange precipitate is the result of the mixture of these
two liquids. This is collected on a filter, well washed and made into a paste with
water. In this condition it is suitable for dyeing and printing on cotton in
combination with the metallic mordants of the iron group. If alumina be used as a
mordant, a blueish pink is produced, whilst a greyish violet is produced on an iron
mordant and a purple on chromium mordants.
If in the above process the diazo benzene chloride be replaced by the corresponding
quantity of paranitro diazobenzene chloride, a dye is produced, which gives somewhat
redder shades on the above named mordants. If again paradiazophenol chloride be
used instead of diazobenzene chloride a dye is produced which dyes all these mordants

page_text: in various shades of grey, and similar variations of shade may be obtained by sub-
stituting other diazo compounds such as diazotolnene or diazoxylene or alpha- and
Betanaphthylamine chloride for the diazobenzene chloride used in my example.
If on the other hand, I intend to prepare a dye suitable for dyeing mordanted
wool or silk I proceed as follows.:
Having prepiously prepared a cold aqueous solution of 160 parts by weight, of
Betanaphtohydroquinone and 150 parts, by weight, of crystallised sodic acetate, I
introduce into this solution an aqueous suspension of 184 parts by weight, of
diazobenzene sulphonic acid, prepared from sulphanilic acid in a manner well known
to chemists. A dark orange solution is the result of this manipulation. From this
solution the new dye-stuff formed may be precipitated by the addition of common
salt, when it settles out as an orange precipitate, which may be collected and dried.
The solution of this dye dyes wool, mordanted with alum, a dark blueish red, whilst
it produces a blueish purple on wool which has been mordanted with chromium
*salts...
If in the above process, I replace the diazobenzene sulphonic acid used by the
corresponding quantity of any other aromatic diazo-sulphonic acid, I obtain other
dyestuffs of various shades all of which possess the peculiarity of dyeing mordanted
wool. Thus, by using, for instance, 234 parts, by weight, of the Beta-diazonaphtalene
sulphonic acid, prepared from Brönners Betanaphtylamine sulphonic acid, I obtain a
dye, the aqueous solution of which is of a deep red shade, whilst it dyes a bright
purple on wool mordanted with alumina and a reddish Indigo shade on wool
mordanted with chromium salts. Again by using 234 parts of Alphadiazonaphtalene
sulphonic acid, prepared from Piria's Naphthionic acid or by using 369 parts of
diazoazobenzene-sulphonic acid I obtain in both cases dyes, which produce a purplish
buff on wool mordanted with alumina and a deep chocolate brown on chromed wool.
And similar variations may be produced by using other diazo sulphonic acids instead
of those here named.
Dated the toil 1
2
הד
1000
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
The Production of New Azo Dyes, Applicable for Dyeing and
Printing.
I, OTTO NICHOLAS WITT of 33 Lindenallee, Westend, Charlottenburg in the Empire
of Germany, Ph. D. F.C.S. 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 :-
My Invention is based upon the new and unexpected discovery that the rule,
according to which ortho dioxy derivatives of aromatic hydro carbones do not yield
azo derivatives if acted upon with diazo compounds, is not applicable to Alpha-Beta-
..orthodioxynaphtalene, a substance, which is more commonly known under the name
of Beta-naphtohydroquinone. If diazo compounds be made to act on a cold aqueous
solution of this compound, azo dyes are invariably produced, in the same manner as
by. the reaction of such diazo compounds upon any other oxy- or dioxy-naphtalene.
The azo dyes produced in this manner from Betanaphtohydro quinone are however
distinguished from almost all other azo dyes by one property which makes them
particularly valuable and useful for dyeing and printing.. This important property
consists in their ability to combine and form insoluble lakes with the metallic oxydes
of the iron group, such as alumina, ferric and chromic oxyde. These new azo dyes
may therefore be dyed, the same as alizarine or logwood on mordanted fibres, on
which they produce useful shades of considerable depth and fastness superior to the
majority of those produced with the azo dyes which have hitherto been in use..
This useful property of combining with the mordants of the iron group is common
to all my new azo dyes produced from Beta-naphtohydroquinone. But it depends

page_text: upon the choice of the diazo compounds combined with the Betanaphtohydro quinone,
whether the azo dye produced is better suited for dyeing and printing on mordanted
cotton or on mordanted wool or silk. If the chloride or any other salt of a non-
sulphonated aromatic diazo compound be allowed to act upon Beta-naphtohydroquinone
an azo dye is produced which is very sparingly soluble in water. The azo dyes of
this class are particularly useful for dyeing and printing cotton. If on the other
hand the sulpho derivatives of aromatic diazo compounds be made to react upon the
said Betanaphtohydroquinone then are azo dyes produced which are very soluble in
water and particularly adapted for dyeing and printing wool and silk.
I shall now proceed to describe the exact process which I prefer for producing
both cotton and wool dyes from Betanaphtohydroquinone.
To produce for instance a cotton dye, I first prepare a solution of diazo benzene
chloride by mixing together at a temperature not exceeding 5° C. 93. parts of aniline
with 200 parts of hydrochloric acid (containing 37 per cent. of anhydrous acid) and
2000 parts of water, and by adding gradually a cold aqueous solution of sodic nitrite,
containing 69 parts of this salt. This solution of diazobenzene chloride I allow to
run into a cold aqueous solution previously prepared by dissolving 160 parts by
weight of Betanaphtohydroquinone and 150 parts of crystallised sodic acetate in
2000 parts of water. A dark orange precipitate is the result of the mixture of these
two liquids. This is collected on a filter well washed and made into a paste with
water. In this condition it is suitable for dyeing and printing on cotton in combination
with the metallic mordants of the iron group. If alumina be used as a mordant a
blueish pink is produced whilst a greyish violet is produced on an iron mordant and
a purple on chromium mordants.
If in the above process the diazobenzene chloride be replaced by the corresponding
quantity of paranitrodiazobenzene chloride, a dye is produced, which gives somewhat
redder shades on the above named mordants. If, again paradiazophenol chloride be
used instead of diazobenzene chloride a dye is produced, which dyes all these
mordants in various shades of grey. And similar variations of shade may be obtained
by substituting other diazo compounds such as diazotolnene or diazoxylene or
alpha- and Betanaphthylamine chloride for the diazobenzene chloride used in my
example.
If on the other hand I intend to prepare a dye suitable for dyeing mordanted
wool or silk, I proceed as follows:-
:-
Having previously prepared a cold aqueous solution of 160 parts by weight of
Betanaphtohydroquinone and 150 parts by weight of crystallised sodic acetate I
introduce into this solution an aqueous suspension of 184 parts by weight of diazo-
benzene sulphonic acid prepared from sulphanilic acid in a manner well known to
chemists. A dark orange solution is the result of this manipulation from this
solution the new dye stuff formed may be precipitated by the addition of common
salt, when it settles out as an orange precipitate which may be collected and dryed.
The solution of this dye dyes wool, mordanted with alum, a dark blueish red, whilst
it produces a blueish purple on wool, which has been mordanted with chromium
salts.
If in the above process I replace the diazobenzene sulphonic acid used by the
corresponding quantity of any other aromatic diazosulphonic acid I obtain other dye
stuffs of various shades all of which possess the peculiarity of dyeing mordanted wool.
Thus by using for instance 234 parts by weight of the Beta-diazonaphtalene sulphonic
acid prepared from Brönners Betanaphtylamine sulphonic acid I obtain a dye, the
aqueous solution of which is of a deep red shade, whilst it dyes a bright purple on
wool mordanted with alumina and a reddish Indigo shade on wool mordanted with
chromium salts. Again by using 234 parts of Alphadiazonaphtalene sulphonic acid
prepared from Piria's Naphthionic acid or by using 369 parts of diazo azobenzene
sulphonic acid I obtain in both cases dyes which produce a purplish buff on wool
mordanted with alumina and a deep chocolate brown on chromed wool. And similar
variations may be produced by using other diazo sulphonic acids instead of those
here named.

page_text: Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I'
claim is :-
.
:-
1. The process for the production of new cotton-azo dyes capable of dyeing the
mordants of the iron group, by acting with non-sulphonated aromatic diazo compounds
upon Betanaphtohydroquinone substantially as set forth.
2. The process for the production of new wool- azo-dyes capable of dyeing the
mordants of the iron group, by acting with sulphonated aromatic diazo compounds
upon Betanaphtohydroquinone substantially as set forth.
3. The new azo- cotton-dyes thus produced.
4. The new azo- wool-dyes thus produced.