IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN COLORING MATTERS BY THE OXIDATION OF SALTS OF ANILINE AND OTHER SALTS OF A SIMILAR NATURE
Year: 1860

page_text: LETTERS PATENT to Edward Joseph Hughes, of the City of Manchester,
in the County of Lancaster, Patent Agent, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN COLORING MATTERS BY THE
OXIDATION OF SALTS OF ANILINE AND OTHER SALTS OF A SIMILAR NATURE."-
A communication from abroad by Paul Depoully and Charles Lauth, of
Clichy, in the Empire of France.
11
Sealed the 13th July 1860, and dated the 24th January 1860.
PROVISIONAL SPECIFICATION left by the said Edward Joseph Hughes
at the Office of the Commissioners of Patents, with his Petition, on
the 24th January 1860.
I, EDWARD JOSEPH HUGHES, of the City of Manchester, in the County of
Lancaster, Patent Agent, do hereby declare the nature of the said Invention.
for "IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN COLORING MATTERS BY THE.
OXIDATION OF SALTS OF ANILINE AND OTHER SALTS OF A SIMILAR NATURE," a com--
munication to me from abroad by Paul Depoully and Charles Lauth,. of Clichy,..
in the Empire of France, to be as follows:-
The characteristic chemical re-action of aniline and its salts are,-
First, violet coloration by means of chloride of lime. The produce of this
treatment has been hitherto considered unstable, and consequently not
employed for industrial use.
Secondly, black precipitate produced by bichromate of potash. This produce
is already the subject of several Patents both in England and France.

page_text: Thirdly, decomposition of the salts of aniline by heat, and the formation of
red and violet coloring matter; which re-action, although very characteristic,
has not been hitherto employed for industrial purposes.
To obtain the violet coloring matter, a solution of salts of aniline is used,
and treated with a solution of chloride of lime (bleaching powder). The first
drop of the solution of chloride applied shews a violet coloration, and if the
process be continued a dark violet precipitate is obtained which constitutes the
said coloring matter almost in a state of purity. The said precipitate is then
filtered and repeatedly washed in slightly acidulated water till the washings
appear colorless, then filtered again and the residue dissolved by a con-
centrated acid (for instance sulphuric or other acid) and when the dissolution is
completed the produce is precipitated with a large quantity of water or with a
suitable quantity of alkaline water; the produce thus obtained is then
sufficiently pure for use.
To obtain the red or reddish violet coloring matter, take nitrate of aniline
and heat it to about two hundred degrees centigrade (or about three hundred
and ninety-two degrees Fahrenheit). After a certain time the mass will
become a fine violet color which may be used in that state or in solution.
If the shades are required to be more red, add to the nitrate of aniline a
quantity of aniline or salts of aniline (acetate, oxalate, &c.) more or less in
proportion to the shade required.
The formation of these coloring matters is herein explained as an oxidation
resulting from the decomposition of the salts of aniline. The said oxidation
may, however, be moderated by an excess of aniline or of some other body
having the function of preventing a secondary re-action.
The object of this Invention is the manufacture of coloring matters such as
violet and red by the oxidation of salts of aniline by means of hypochlorites
or hypochlorous acid for violets, and of nitric acid for reds.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Joseph Hughes in the Great Seal Patent Office on 3
the 23rd July 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JOSEPH HUGHES, of the City of Manchester, in the County of Lancaster,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Twenty-fourth day of January, in the year of our Lord

page_text: One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Edward Joseph Hughes, Her special licence that I, the said Edward
Joseph Hughes, my executors, administrators, and assigns, or such others
as I, the said Edward Joseph Hughes, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "Im-,
PROVEMENTS IN THE MANUFACTURE OF CERTAIN COLORING MATTERS BY THE OXIDATION:
OF SALTS OF ANILINE AND OTHER SALTS OF A SIMILAR NATURE," being a communi-
cation from abroad by Paul Depoully and Charles Lauth, of Clichy, in the
Empire of France, upon the condition (amongst others) that I, the said Edward
Joseph Hughes, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Edward Joseph Hughes, do hereby
declare the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and. ascertained in and by the fol-
lowing statement (that is to say)
1 mix in a suitable vessel for distillation aniline with nitric acid in the
proportion of two hundred parts of aniline and sixty-five parts of nitric acid,
specific gravity 1.360. The mixture is heated on a sand bath or by other
means from 300° to 400° Fahrenheit. Part of the aniline which distils over
with the water of the nitric acid may be used again in future operations.
After all the water has been distilled the product is kept in a state of ebullition
for about an hour; it becomes a thick syrup of a dark red color; it is then
put into a suitable vessel, a small quantity of water added, and neutralized
with a solution of carbonate of soda, afterwards well washed with water until
the water appears colorless or slightly red. The product is then dried by heat
to remove the remaining water. The produce thus washed and dried is fit for
the trade; it contains, however, besides the red coloring matter, a resin of a
brownish violet color, to remove which I adopt the following method:-Boil
twenty parts of pure water, and add while boiling one part of the product, and
continue to heat until the whole of the resin is removed from the surface by
skimming; the solution is then filtered through a layer of sand, and on cooling

page_text: deposits a green paste with a metallic reflection. The water is drawn off, and
may be used again in the next operation. The red coloring matter left may
be used either. in the above state or in a solution of acetic acid, alcohol, or any
other suitable solvent.
Having thus fully described the nature of the said Invention, and the
manner in which the same is to be performed, I desire it to be distinctly
understood that I do not confine myself to the exact proportions of the
materials as herein set forth, as such may be varied according to the shade of
color required; and, if desired, part of the aniline may also be substituted by
aniline combined with a weak acid, such as acetic, oxalic, &c.; but I claim,
the production of a red and violet coloring matter by the action of nitric acid
upon. aniline or salts of aniline.
In witness whereof, I, the said Edward Joseph Hughes, have hereunto
set my hand and seal, this Twenty-first day of July, in the year of
our Lord One thousand eight hundred and sixty.
Signed, sealed, and delivered by the within-
named Edward Joseph Hughes, in the
presence of
GEO. SEP. HUGHES,
17, Cross Street,
Manchester.
E. J. HUGHES. (L.S.)