THE PREPARATION OF CERTAIN COLOURING SUBSTANCES FOR PRINTING AND DYEING, OR OTHER PURPOSES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Emile Huber at the Office of
the Commissioners of Patents, with his Petition, on the 24th December
1859.
I, EMILE HUBER, of Paris, in the French Empire, Chemist, do hereby
declare the nature of the said Invention for "THE PREPARATION OF CERTAIN
COLOURING SUBSTANCES FOR PRINTING AND DYEING, OR OTHER PURPOSES," to be as
follows:-
The object of the Invention is, the transformation of napthaline into nitro-
napthaline, napthylamine, and salts, or compounds of napthylamine, and the
transformation into colouring matters. of the napthylamine and salts, or
compounds of napthylamine by oxidizing and other agents, and the modi-
fication and alteration of such colouring matters by means of re-agents, and
the application of the same for printing, dyeing, or otherwise colouring silk,
wool, cotton, skins, feathers, and other articles, either with or without
mordants. The napthaline is employed in the yellowish white state, in which
it is obtained by the distillation of tar. If not sufficiently pure, 1 re-distil it:
Ten parts by weight of napthaline are then mixed with twelve parts of cold
nitric acid, of forty degrees of Baume's areometer. The substance melts and
evolves nitrous vapours. When the disengagement of vapours diminishes, I
agitate the mixture, and pour into it by small portions two parts of nitric acid

page_text: and eighteen parts of sulphuric acid of sixty-six degrees, stirring the mixture
at the same time, and regulating the additions of acid by the disengagement
of nitrous vapours, which ought to be very slight. The reaction lasts about
twelve hours, and a sufficient heat should be maintained to keep the nitro-
napthaline in fusion. The nitric acid may be used at thirty-six degrees, but
the sulphuric acid must then be increased to about thirty parts. The nitric
acid should not be much stronger than forty degrees, lest the reaction should
become too violent, and produce binitrobenzine. A compact crust forms on
the surface of the acids on cooling. The acids are drawn off, and the crust is
washed with boiling water containing a little carbonate of amnionia or soda.
The nitronapthaline is thus melted, and on cooling forms a compact reddish
yellow mass, having a clean fracture. The nitronapthaline is then submitted
to the action of reducing or deoxidizing substances. Thus, hydrochloric acid
and iron, or sulphuric acid and zinc, or acetic acid and iron may be employed.
I mix fifteen parts by weight of wood vinegar of seven or eight degrees of
Baumé's areometer or acidometer with twenty-five part by weight of clean
iron turnings, and twelve parts of nitronapthaline. The action would be very
violent, but is moderated by the addition of two or three parts of alcohol. The
mixture becomes resinous, and is allowed to cool. The black resinous mass is
distilled by a naked fire to dryness or calcination. The distilled liquid is rose
coloured, and charged with a resinous matter, which solidifies on cooling, and
is denser than the rose coloured solution, which is acetate of napthylamine.
To obtain the napthylamine, I filter the products of distillation, wash them
with cold water, and saturate the filtered liquor with ammonia. The napthy-
lamine precipitates as a substance of an ocreous colour, which is purified by
washing. The pure napthylamine treated by weak nitric acid gives a pre-
cipitate which, after being washed with water and dried, is dissolved in alcohol,
to which it communicates a red colour. By the use of other reagents, various
tints and colours are produced. By adding bydrochloric acid to the aforesaid
rose coloured liquor I obtain a purple solution. Sulphuric acid produces a
reddish blue, and weak nitric acid a colour like the dregs or lees of wine.
Organic acids produce various tints.
The resinous deposit of the distillation which is collected on the filter after
being washed and dried at 212° Fah. or thereabouts is treated with dilute
hydrochloric acid, and afterwards filtered. The liquid passes through colour-
Jess, but the deposit has undergone a change; by exhausting it with alcohol,
a solution of a pansy violet colour is obtained. The same resinous deposit
washed, dried, and treated with dilute nitric acid, affords in a similar manner

page_text: a deep violet soluble in alcohol; the same resinous deposit washed, dried, and
treated with alcohol gives a solution of an orange colour similar to that of the
solar spectrum. There still remains on the filter, after the action of the
alcohol, a deposit which is partly soluble in acetic acid, and communicates to
its solution a pansy blue colour. The rose-coloured liquor and the resinous
deposit treated together by an oxidizing agent as the bichromate of potash in
a cold aqueous solution and then filtered, gives a deposit which, after being
washed and dried, gives with alcohol a red solution. The rose-coloured
solution treated alone in a similar manner gives a deposit soluble in acetic
acid which it colours lilac blue. If in place of an acetate I employ a sulphate
of napthylamine, a sufficient quantity of bichromate of potash should be used
to form a neutral sulphate with the potash of the bichromate.
bichromate is not injurious, except that it requires that the precipitate should
be more carefully washed with water; the deposit or precipitate thus obtained
by oxidizing agents may have its colour modified by the means previously
mentioned, and becomes soluble in alcobol. Thus weak hydrochloric acid
poured on the filter passes colourless, but the deposit is changed and rendered
soluble in alcohol, which it colours pansey blue. Other acid reagents act in a
similar manner; the proportious of the materials admit of variation.