The Manufacture or Production of Azo Colouring Matters.
Year: 1899

page_text: Date of Application, 16th Dec., 1899
Complete Specification Left, 30th June, 1900-Accepted, 4th Aug., 1900
PROVISIONAL SPECIFICATION.
The Manufacture or Production of Azo Colouring Matters.
We, IVAN LEVINSTEIN, Managing Director, CARL MENSCHING, Ph.D., Chemist,
and LEVINSTEIN LIMITED, all of Minshull Street, Manchester, in the County
of Lancaster, do hereby declare the nature of this invention to be as follows:-
We have found that if acetyl-para-amidobenzene-azo-amido-alpha-naphtha-
lene is diazotised and combined with naphthol sulphonic acids and the acetyl
group subsequently split off, valuable azo-dye-stuffs are produced which dye
wool in a neutral or acid bath, deep black shades which are fast to light and to
washing.
To obtain these colouring matters we may, by way of example, proceed as
follows: 30.4 kilos. of acetylpara-amidobenzene-azo-amido-alpha-naphthalene is
suspended in 300 litres of water containing 70 kilos. of hydrochloric acid of
about 18° Bé. The mixture is cooled down with ice to 5° C. and then 7.5 kilos.
of sodium nitrite is added with stirring. The resulting diazo compound is
added to a solution of 35 kilos. of naphthol salt R, and 44 kilos. of soda.
The azo colour, which forms immediately, is heated to 80° C., salted out
and filtered; it is then dissolved in 1000 litres of water and saponified in the
usual way. After saponification, the colouring matter may be salted out,
filtered, pressed and dried.
Similar colouring matters may be obtained from paranitro-benzene-azo-amido-
alpha-naphthalene by diazotising and combining it with naphthol sulphonic
acids, and reducing the azo colours thus formed, in alkaline solution with
sodium sulphide.
The new azo dye-stuff is a black powder easily soluble in hot water with a
blueish-black colour. In concentrated sulphuric acid it dissolves with a dull
greenish blue, which, on dilution, becomes red and then decolourised.
It dyes wool, in an acid bath, a deep black.
Similar colouring matters may be obtained by employing other naphthol
sulphonic acids, such as Schaeffers' salt and the like, in substitution for the
naphthol salt R, the shades varying from reddish to blueish black.
Dated this Fifteenth day of December A.D. 1899.

page_text: chester, in the County of Lancaster, do hereby declare the nature of this inven-
tion, 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 if acetyl-para-amidobenzene-azoamido-alpha-naphtha-
lene is diazotised and combined with naphthol sulphonic acids and the acetyl
group subsequently split off, valuable azo dye-stuffs are produced which dye
wool in a neutral or acid bath, deep black shades which are fast to light and to
washing.
To obtain these colouring matters we may, by way of example, proceed as
follows:-
30.4 kilos. of acetyl-para-amidobenzene-azoamido-alpha-naphthalene is
suspended in 300 litres of water containing 70 kilos. of hydrochloric acid of
about 18° Bé. The mixture is cooled down with ice to 5° C. and then 7.5 kilos.
of sodium nitrite is added with stirring. The resulting diazo compound is
added to a solution of 35 kilos. of naphthol salt R, and 44 kilos. of soda.
The azo colour, which forms immediately, is heated to 80° C., salted out
and filtered. It is then dissolved in 1000 litres of water and saponified in the
usual way to split off the acetyl group. After saponification, the colouring
matter may be salted out, filtered, pressed and dried.'
Similar colouring matters may be obtained from para-nitrobenzene-azo-amido-
alphanaphthalene by diazotising and combining with naphthol sulphonic
acids, and reducing the azo colours thus formed, in alkaline solution with
sodium sulphide.
The new azo dye-stuff is a black powder easily soluble in hot water with a
blueish-black colour. In concentrated sulphuric acid it dissolves with a dull
greenish blue, which, on dilution, becomes red and then decolourised.
It dyes wool, in an acid bath, a deep black.
Similar colouring matters may be obtained by employing other naphthol
sulphonic acid, such as Schaeffer's salt and the like, in substitution for the
naphthol salt R, the shades varying from reddish to blueish black.
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 an azo colouring matter by the
diazotisation of acetyl-para-amidobenzene-azoamido-alpha-naphthalene, the com-
bination of the resulting product with a naphthol sulphonic acid, and the
elimination of the acetyl group, substantially as hereinbefore described.
2. The manufacture or production of an azo colouring matter by the diazotisa-
tion of para-nitrobenzene-azoamido-alphanaphthalene, the combination of the
resulting product with a naphthol sulphonic acid, and the reduction of the thus
produced azo colouring matter with sodium sulphide in an alkaline solution,
substantially as hereinbefore described.
3. As new articles of manufacture, the new black azo colouring matters pro-
duced substantially as and by the means herein before described.
Dated this 27th dow of Inne A D 1900