Improvements in the Manufacture of Mordant-dyeing Colouring. matters.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Mordant-dyeing Colouring.
matters.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention, (which has been
communicated to me by The Badische Anilin & Soda Fabrik,. of Ludwigshafen-
on-Rhine, in the German Empire,) to be. as follows:-
In the Specifications of Letters Patent Nos. 19588 and 19589 of 1891, the first
commercial process for the manufacture of the blue mordant-dyeing colouring-
matters, known as anthracene blue, is described. These colouring matters were
obtained by heating a dinitro-anthraquinone with fuming sulphuric acid, where-
by soluble colouring matters are obtained, and then treating the said soluble
colouring-matters with a weaker sulphuric acid, whereby they are converted into
comparatively insoluble colouring-matters.
In the Specification of Letters Patent 13029 of 1892 a further improvement in
this process is described, which consists in the use of a partially reduced dinitro-
anthraquinone body, or of the addition of a suitable reducing agent, such as
sulphur, to the fuming sulphuric acid melt during the first stage of the process.
Subsequently it has been described that good results could be obtained if
boracic acid be added to the fuming sulphuric acid melt, and still later, in the
Specification of Letters Patent 16495 of 1897 it has been shewn that very valuable
colouring-matters can be obtained by the simultaneous use of sulphur and boracic
acid in the fuming sulphuric acid melt. The said colouring-matters thus obtained
by the simultaneous use of sulphur and boracic acid are entirely different from
the colouring-matters obtained under the same conditions but using sulphur, or
boracic acid, alone.
The present invention relates to the conversion of the comparatively soluble
colouring-matters thus obtained, in accordance with the process described in the
Specification of the said Letters Patent 16495 of 1897, and using a fuming sul-
phuric acid containing about 45 per cent. free SO,, into comparatively insoluble
colouring-matters by treatment with concentrated sulphuric acid. The colouring-
matters thus obtained differ from those from which they are prepared in that
they give a red-violet solution in concentrated sulphuric acid, and that they dye
cotton that has been mordanted with alumina, reddish shades, whilst the initial
colouring-matters yield blue-violet shades. The following example will serve to
further illustrate the nature of the invention, but the invention is not restricted
to this example.

page_text: it from five to six times its weight of sulphuric acid (containing about 63 per cent.
H2SO4). Heat the mixture for from one to two hours to a temperature of
130 to 140 degrees Centigrade. Collect the colouring-matter in the usual way.
If desired, the soluble colouring-matter that is used as initial material can be
isolated prior to treatment according to this invention, but the process of the
example is simpler.
Thin 5th day of December 1898
Improvements in the Manufacture of Mordant Dyeing Colouring
Matters.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention, (which has been
communicated to me from abroad by The Badische Anilin & Soda Fabrik, of
Ludwigshafen-on-Rhine, in the German Empire) and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement : —
_
In the Specifications of Letters l'atent Nos. 19588 and 19589 of 1891, the first
commercial process for the manufacture of the blue mordant-dyeing colouring-
matters, known as anthracene blue, is described. These colouring matters were
obtained by heating a dinitro-anthraquinone with fuming sulphuric acid (where-
by soluble colouring matters are obtained) and then treating the said soluble
colouring matters with a weaker sulphuric acid, whereby they, are converted into
comparatively insoluble colouring-matters.
In the Specification of Letters Patent 13029 of 1892 a further improvement in
this process is described which consists in the use of a partially reduced dinitro-
anthraquinone body, or of the addition of a suitable reducing agent, such as
sulphur, to the fuming sulphuric acid melt during the first stage of the process.
Subsequently it has been described that good results could be obtained if
boracic acid be added to the fuming sulphuric acid melt and still later, in the
Specification of Letters Patent 16495 of 1897 it has been shewn that very valuable
colouring-matters can be obtained by the simultaneous use of sulphur and boracic
acid in the fuming sulphuric acid melt. The said colouring matters thus obtained
by the simultaneous use of sulphur and boracic acid are entirely different from
the colouring matters obtained under the same conditions, but using sulphur, or
boracic acid, alone.
.
The present invention relates to the conversion of the comparatively soluble
colouring-matters thus obtained when simultaneously using sulphur and
boracic acid in accordance with the process described in the Specifi-
cation of the said Letters Patent 16495 of 1897 and using a fuming sul-
phuric acid containing say about 45 per cent. free SO, into comparatively insoluble
colouring matters, by treatment with concentrated sulphuric acid. The colouring
matters thus obtained differ from those from which they are prepared in that
they give a red-violet solution in concentrated sulphuric acid, and that they dye
cotton that has been mordanted with alumina reddish shades, whilst the initial
colouring matters yield blue-violet shades. The following example will serve to
further illustrate the nature of the invention and the manner in which it can be
performed but the invention is not restricted to this example.

page_text: EXAMPLE:
Prepare a colouring matter melt, according to Example 2 of the Specification
of the said Letters Patent 16495 of 1897, using a fuming sulphuric acid (con-
taining about 45 per cent. free anhydride). Allow the melt to cool, and add to
it from five to six times its weight of sulphuric acid (containing about 63 per cent.
HSO). Heat the mixture for from one to two hours to a temperature of from
130 to 140 degrees Centigrade. Collect the colouring-matter in the usual way.
If desired, the soluble colouring-matter that is used as initial material can be
isolated prior to treatment according to this invention, but the process of the
example is simpler.
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 manufacture of comparatively insoluble mordant dyeing colouring
matters by treating the comparatively soluble colouring-matters hereinbefore
defined with concentrated sulphuric acid at a high temperature.
2. The manufacture of mordant-dyeing colouring-matter substantially as
hereinbefore described in the example.
3. As a new article of manufacture the mordant-dyeing colouring matter, such
as can be obtained as hereinbefore described.
Dated this 22nd day of August 1899.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.