Improvements in the Production of Black Azo Colours upon Fibres.
Year: 1891

page_text: Date of Application, 6th June, 1891
Complete Specification Left, 9th July, 1891-Accepted, 15th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Production of Black Azo Colours upon
Fibres.
1, BENJAMIN WILLCOX of 47 Lincolns Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention which has been com-
municated to me from abroad by Farbenfabriken vormals Friedrich Bayer and
Company of Elberfeld in the Empire of Germany to be as follows:-
In the Specification of my application for Letters Patent No. 8530 of 1890 it
has been shewn that the direct dyeing azo colouring matters obtained by the
combination of the tetrazo compounds of benzidine and its anologues with amido-
naphthol mono-sulpho-acid G (para-amido-naphthol-mono-sulpho-acid) can be
further diazotized upon fibres previously dyed therewith and then united with any
dyestuff components thereby producing from violet-black to bluish-black and green-
black colours.
My foreign correspondents have now discovered that the para-amido naphthol
mono-sulpho-acid employed in this process can be advantageously replaced by those
amido-naphthol-di-sulpho acids which are obtained by melting with alkalies the
alpha-naphthylamine-tri-sulpho-acid obtained by nitrating and reducing the
naphthaline-tri-sulpho-acid described in the Specification to the German Patent
38281.
Good results are obtained with the following dyestuffs of the amido-naphthol di-
sulpho acid.
i. The combination of one molecular proportion of the tetrazo compounds of
benzidine, tolidine, diamnido-phenyl-tolyl, diamido-alkyl-oxy-diphenyl-diamido alkyl-
oxy-phenyl-tolyl, diamido-di-phenol-ether, diamido diphenoxy-acetic acid, diamido-
stilbene, diamido-fluorene, para-phenylene-diamine, diamido-naphthalin, diamido-
diphenylene-oxide diamido-ditoluylene-oxide, benzidine-sulphone-tolidine-sulphone
and their sulpho- and carboxy-acids with two molecular proportions of the amido-
naphthol-disulpho acid.
2. The combinations of one molecular proportion of the tetrazo compounds
hereinbefore specified with one molecular proportion of amido-naphthol-disulpho-
acid and with one molecular proportion of another dyestuff component or again
with those dyestuffs which are obtained by coupling the intermediate product
(obtained from one molecular proportion of the tetrazo compounds and one
molecular proportion of a dyestuff component,) with the amido-naphthol-di-sulpho-
acid.
3. Those dyestuffs which are formed by the combination of one, molecular
proportion of the tetrazo compounds with one or two molecular proportions of
alpha-naphthylamine, or alpha-amido-naphthol-ether further diazotizing the azo-
body formed and uniting with two molecular proportions of amido-naphthol-di-
sulpho-acid or with one molecular proportion of the same and then with one
molecular proportion of another dyestuff component.
The process for producing black upon the fibre by the aid of these combinations
will be understood from the following example.
About 10 kilos. of cotton are dyed by inmersion for say one hour in a boiling
solution prepared by dissolving 0.6 kilos. of the colouring matter obtained from
tetrazo-di-phenyl and amido-naphthol-disulpho-acid in 200 litres of hot water and
adding 1 kilo. of common salt after which the cotton is well rinsed.
The blue dyed cotton is then placed in a solution of 0.2 kilos. of sodium nitrite
in 200 litres of cold water acidulated with 0.6 kilos. of hydrochloric acid
(20° Baume) and well agitated therein.

page_text: The cotton then acquires a green-black colour corresponding with the diazo-
compound of the dye-stuff. When the diazotizing is completed the cotton, after
well rinsing is placed in a watery solution of 0.5 kilos. of the sodium salt of beta-
naphthol.
The cotton gradually becomes black and after remaining some time in the bath
the coupling is completed.
The black tones thus obtained are very fast to washing. The brightness and
beauty of the black are improved by this treatment.
By employing others of the combinations hereinbefore specified in place of the
dyestuff from tetrazo-diphenyl and amido-naphthol-disulpho-acid or by employing
any other dyestuff components in place of the sodium salt of beta-naphthol-violet-
black, brown-black, blue-back, and green-black shades are obtained.
Dated this 6th day of June 1891
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in the Production of Black Azo Colours upon
Fibres.
I BENJAMIN WILLCOX of 47 Lincolns Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention which has been com-
municated to me from abroad by The Farbenfabriken vormals Friedrich Bayer and
Company of Elberfeld 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 my application for Letters Patent No. 8530 of 1890 it
has been shewn that the direct dyeing azo colouring matters obtained by the
combination of the tetrazo compounds of benzidine and its analogues with amido-
naphthol-mono-sulpho-acid G (para-amido-naphthol-mono-sulpho acid) can be
further diazotised upon fibres previously dyed therewith and then united with any
dyestuff component thereby producing from violet-black to bluish-black and green-
black colours.
My foreign correspondents have now discovered that the para-amido-naphthol-
mono-sulpho-acid employed in this process can be advantageously replaced by that
amido-naphthol-disulpho-acid which they have produced (see the application for
Patent 134430) by melting with alkalies the alpha-naphthylamine-tri-sulpho-acid
obtained by nitrating and reducing the naphthalene-tri-sulpho-acid described in the
Specification to the German Patent 38281.
Good results are obtained with the following dyestuffs of the amido-naphthol-di-
sulpho acid which are also described under the aforesaid application for Patent
No. 1344390.
1. The combination with two molecular proportions of the aforesaid amido-
naphthol-disulpho acid of one molecular proportion of the tetrazo compounds of
benzidine ortho-tolidine; para-diamido-phenyl-ortho-tolyl; diamido-ortho-di-
phenol-ether; para-diamido-alkyl-oxy-di-phenyl; para-diamido-alkyl-oxy-phenyl-
tolyl; diamido-ortho-di-phenol-ether; diamido-diphenoxyl-acetic-acid; para diamido-
stilbene diamido-fluorene; a 1 a 3 diamidonaphthalene.
2. The colouring matters obtainable by combining one molecular proportion of
the tetrazo compounds herein before specified with one molecular proportion of the
amido-naphthol-disulpho-acid and with one molecular proportion of another
dyestuff component as well as those dyestuffs which are obtained by operating in a
reverse order and coupling the intermediate products obtained from one molecular
proportion of the tetrazo compounds and one molecular proportion of another
dyestuff component with one molecular proportion of the amido-naphthol-di-sulpho-
acid.

page_text: 3. Those dyestuff's which are formed by combining one molecular proportion of
the tetrazo compounds with either one or two molecular proportions of alpha-
naphthylamine, or alpha-amido-naphthol-ether then further diazotising the azo
compounds thus obtained and combining the resulting diazo-compounds either with
two molecular proportions of amido-naphthol-di-sulpho-acid or with one mole-
cular proportion of the latter and with one molecular proportion of another dyestuff'
component.
The process for producing black colours upon the fibre by the aid of the
aforesaid dye stuff combinations may be carried out in the following manner.
About 10 kilos. of cotton are dyed by immersion for one hour in a boiling
solution prepared by dissolving in 200 litres of hot water 1 kilo. of common salt
and 0-6 kilos. of the colouring matter obtained, for example, from one molecular
proportion of tetrazo-di-phenyl and two molecular proportions of amido-naphthol-
disulpho-acid.
The blue dyed cotton after having been carefully rinsed is then put into a
solution of 0.2 kilos. of sodium nitrite in 200 litres of cold water acidulated with
0-6 kilos. of hydrochloric acid (20° Bauné) and well agitated therein. The cotton
then assumes the greenish-black colour which is characteristic of the diazo com-
pound of the dyestuff itself. When the diazotising is completed the cotton, is well
rinsed and is then introduced into a solution in water of 0.5 kilos. of the sodium
salt of beta-naphthol.
The cotton gradually becomes black and after remaining for some time in the
bath the coupling is completed.
The black shades thus obtained are very fast against washing; and their
brightness and beauty are increased by this application.
When instead of the dyestuff from tetrazo-diphenyl and amido-naphthol-disulpho-
acid the above mentioned analogous combinations are employed or when in place of
the sodium salt of beta-naphthol other dyestuff components are employed violet-
black, brown-black, blueish-black, to greenish-black shades of the same fastness
and beauty result.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
The production of black azo dyestuffs on fibres by dyeing cotton at first with
those colouring matters from amidonaphtholdisulpho acid which still contain one
free amido group as herein before described under heads I, II, and III by diazo-
tising the dyestuff fixed upon the fibres and by combining the diazo derivatives
thus obtained with phenols, amines, amido-phenols, their sulpho or carboxylic
acids.
Datod this 9th day of July 1891.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.