The Manufacture or Production of Polyazo Dyestuffs.
Year: 1899

page_text: Date of Application, 7th Nov., 1899
Complete Specification Left, 30th June, 1900-Accepted, 4th Aug., 1900
PROVISIONAL SPECIFICATION.
The Manufacture or Production of Polyazo Dyestuffs.
We, CARL MENSCHING, D.Ph., Technical Chemist, IVAN LEVINSTEIN, Chemical
Manufacturer, and LEVINSTEIN LIMITED, Chemical Manufacturers, all of 21,
Minshull Street, Manchester, in the County of Lancaster, do hereby declare the
nature of this invention to be as follows:-
We have found that very valuable poly-azo dye-stuffs, which dye cotton a
deep blueish to greenish black, may be produced in the following manner.
Acetyl-para-phenylenediamine is diazotised and combined with gamma-amido-
naphthol-sulphonic acid and the resulting azo-colour is further diazotised and
combined with naphthylamine-sulphonic acids. The polyazo dyestuffs thus
obtained are saponified in the usual manner and the resulting diamido com-
pounds, after having been diazotised, are combined with one molecular proportion
of a meta-diamine.
We have found that in the herein before described diazotisation of the diamido-
azo colouring matter, the amido group in the benzene ring is first attacked by
the nitrite and that the amido group of the naphthylamine ring is attacked by
the second molecule of the nitrite.
The colouring matters produced by tetrazotising and combining with two mole-
cules of the well known dye-stuff components are of no value.
We may proceed as described in the following example,
15 kilos. of acetyl-para-phenylenediamine are diazotised with 6'9 kilos. of
sodium nitrite and the resulting diazo compound is combined, in an alkaline solu-
tion, with 24 kilos. of amidonaphthol-sulphonic acid (gamma.) The product thus
obtained is salted out and filtered and, after having been further diazotised with
6.9 kilos of sodium nitrite, it is stirred for 24 hours. This diazo body is then
combined, in alkaline solution, with alpha,-amidonaphthalene-beta,sulphonic
acid. The resulting dye-stuff is then saponified in the usual way and the colour-
ing matter thus obtained is diazotised with 6.9 kilos of sodium nitrite and com-
bined with 10.8 kilos of meta-phenylenediamine.
The product, when filtered and dried, forms a black powder which is soluble
in hot water with a blue-black colour. Its solution in concentrated sulphuric
acid has a blue colour which becomes redder by aqueous dilution, the colouring
matter being ultimately precipitated. It dyes cotton a deep black.
Colouring matters similar in shade result, if, in the above example, alpha-
or beta-naphthylamine-sulphonic acids le substituted for the alpha,naphthylamine-
beta,-sulphonic acids.
Dated this 20th day of October A.D. 1899.
The Manufacture or Production of Polyazo Dyestuns.
We, CARL MENSCHING, Ph.D., Technical Chemist, IVAN LEVINSTEIN, Chemical
Manufacturer, and LEVINSTEIN LIMITED, Chemical Manufacturers, all of 21,
[Price 8d.1

page_text: Minshull Street, Manchester, in the County of Lancaster, 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:-
We have found that very valuable poly-azo dye-stuffs, which dye cotton a
deep blueish to greenish black, may be produced in the following manner.
Acetyl-para-phenylenediamine is diazotised and combined with gamma-amido-
naphthol sulphonic acid and the resulting azo colour is further diazotised and
combined with naphthylamine sulphonic acids. The polyazo dyestuffs thus
obtained are saponified in the usual manner and the resulting diamido com-
pounds, after having been diazotised, are combined with one molecular proportion
of a meta-diamine.
We have found that in the hereinbefore described diazotisation of the diamido-
azo colouring matter, the amido group in the benzene ring is first attacked by
the nitrite and that the amido group of the naphthylamine ring is attacked by
the second molecule of the nitrite.
The colouring matters produced by tetrazotising and combining with two mole-
cules of the well known dye-stuff components are of no value.
We may proceed as described in the following example.
15 kilos of acetyl-para-phenylenediamine are diazotised with 6.9 kilos of sodium
nitrite and the resulting diazo compound is combined, in an alkaline solution,
with 24 kilos of amidonaphthol sulphonic acid (gamma). The product thus
obtained is salted out and filtered and, after having been further diazotised with
6.9 kilos of sodium nitrite, it is stirred for 24 hours. This diazo body is then
combined, in alkaline solution, with alpha-amidonaphthalene-beta,sulphonic
acid. The resulting dye-stuff is then saponified in the usual way and the colour-
ing matter thus obtained is diazotised with 6.9 kilos of sodium nitrite and com-
bined with 10.8 kilos of meta-phenylenediamine.
The product, when filtered and dried, forms a black powder which is soluble
in hot water with a blue-black colour. Its solution in concentrated sulphuric
acid has a blue colour which becomes redder by aqueous dilution, the colouring
matter being ultimately precipitated. It dyes cotton a deep black.
Colouring matters similar in shade result, if, in the above example, alpha-
or beta-naphthylamine sulphonic acids be substituted for the alpha,naphthylamine-
beta,-sulphonic acids.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
1. The manufacture or production of polyazo dye-stuffs by diazotising acetyl-
para-phenylenediamine, combining the product with amidonaphthol sulphonic
acid gamma, further diazotising the resulting azo colour, combining it with a
naphthylamine sulphonic acid, saponifying the resulting polyazo colour to
eliminate the acetyl group, again diazotising the resulting diamidoazo compounds
and combining them with one molecular proportion of a meta-diamine, sub-
stantially as set forth.
2. As new articles of manufacture, the new colouring matters which are produced
as set forth in the preceding claim, and which dye cotton goods a deep black, sub-
stantially as set forth.