IMPROVEMENTS IN OBTAINING
Year: 1860

page_text: LETTERS PATENT to John Dale, of Manchester, in the County of
Lancaster, Manufacturing Chemist, and Heinrich Caro, of the same
Place, Chemist, for the Invention of
"IMPROVEMENTS IN OBTAINING
Sealed the 20th November 1860, and dated the 26th May 1860.
PROVISIONAL SPECIFICATION left by the said John Dale and Heinrich
Caro at the Office of the Commissioners of Patents, with their Petition,
on the 26th May 1860.
We, JOHN DALE, of Manchester, in the County of Lancaster, Manu-
facturing Chemist, and HEINRICH CARO, of the same Place, Chemist, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN OBTAINING
COLOURING MATTERS FOR DYEING AND PRINTING," to be as follows-
Our invention relates to obtaining colouring matters of purple and red
shades from pure or commercial aniline. For the purple, salts of aniline are
dissolved in water, and mixed with solutions of perchloride of copper, or with
mixtures containing soluble salts of copper and alkaline chlorides, as chlorides
of potassium, sodium, or ammonium. By heating these solutions a black or
dark purple precipitate is formed, which is afterwards filtered and washed.
Boiling water extracts then a purple colour, the remainder contains another
portion of colouring matter, soluble in alcohol. The colours of a red shade
are produced by treating aniline with an anhydrous metallic nitrate and an-
hydrous acids, of the former of which we have found nitrate of lead to answer,
and of the latter anhydrous sulphuric, phosphoric, arsenic, antimonic acids.

page_text: This mixture soon assumes a yellow colour, which is ultimately converted into
a dark red colour, which contains the red shades, and which can be extracted
by boiling water. Also, we treat aniline with nitrate of bismuth under heat,
by which means a coloring matter for red shades is produced, soluble in
water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Dale and Heinrich Caro in the Great Seal Patent
Office on the 26th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
DALE, of Manchester, in the County of Lancester, Manufacturing Chemist,
and HEINRICH CARO, of the same Place, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, 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 us, the said John Dale
and Heinrich Caro, Her special licence that we, the said John Dale and
Heinrich Caro, our executors, administrators, and assigns, or such others
as we, the said John Dale and Heinrich Caro, our executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and 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 "IMPROVEMENTS IN OBTAINING COLOURING
MATTERS FOR DYEING AND PRINTING," upon the condition, amongst others,
that we, the said John Dale and Heinrich Caro, by an instrument in writing
under our hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, 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 wc, the said John Dale and Heinrich Caro, do
hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
Our Invention relates to obtaining colouring matters of purple and red
shades from pure or commercial aniline. For the purple, salts of aniline are
dissolved in water, and mixed with solutions of perchloride of copper, or with

page_text: mixtures containing soluble salts of copper and alkaline chlorides, as chlorides
of potassium, sodium, or ammonium. By heating these solutions to their
boiling point a black or dark purple precipitate is formed containing the
colouring matters.
An example of carrying out our Invention is as follows:-We take one
equivalent of a neutral salt of aniline, as for instance, sulphate, nitrate,
chloride, or acetate of aniline, and six equivalents of perchloride of copper, or
a mixture containing six equivalents of a soluble salt of copper, as, for instance,
sulphate, nitrate, chloride, or acetate of copper, and from six to twelve
equivalents of an alkaline chloride, such as chloride of potassium, sodium, or
ammonium. These salts are then dissolved in a suitable quantity of water,
say, thirty parts of water to one part of aniline contained in the mixture. By
heating these solutions to their boiling point a black or dark purple precipitate
is formed containing the purple colouring matters. The formation of this
precipitate being completed, the whole is filtered, and well washed afterwards
with a weak solution of an alkali or an alkaline carbonate, until the filtering
liquor no longer contains any chloride. Boiling water then extracts a purple
colour, the solution of which may be further concentrated by evaporation, or
the colouring matter may be precipitated by the addition of a small quantity
of an alkali or an alkaline carbonate, and redissolved again in alcohol, or
methylated spirit, when it will constitute a dye suitable for printing or dyeing.
The remainder of the black precipitate insoluble in boiling water is then dried
at 212° F., and repeatedly treated with boiling diluted alcohol or methylated
spirit, of about 0'95 specific gravity, until the whole of the purple colouring
matter has been dissolved out. The solution thus obtained is then heated in
a still until the whole of the alcohol has been recovered, and the colouring
matter is precipitated afterwards by rendering the solution slightly alkaline by
the addition of an alkali or an alkaline carbonate. The precipitate thus
produced is filtered, dried at 212° F., and may or may not be redissolved in
strong alcohol or methylated spirit, when it will be suitable for printing or
dyeing in the ordinary manner, as in use for aniline purples.
The second part of our Invention consists in producing colours of a red
shade by treating aniline with an anhydrous metallic nitrate and anhydrous
acids; as an example, we proceed as follows:-We put two parts of aniline
and two parts of nitrate of lead, perfectly dry and finely powdered into a glass
or other suitable vessel, and raise the temperature of this mixture to the
boiling point of aniline. We then add by small portions at a time one part of
anhydrous phosphoric acid, maintaining the mixture with constant stirring
it at a temperature not exceeding 380° F. At the expiration of one and a

page_text: half to two hours the action will be complete, the contents of the vessel
become very thick, and of a deep bluish red colour. The whole is now
treated with boiling water until all soluble colour is dissolved out. This
solution is carefully filtered while hot, and the red colour precipitated therefrom
by addition of common salt. The precipitate is then filtered, dried at 212° F.,
and dissolved, if required, in alcohol or methylated spirit, and it is in this
state fit for dyeing and printing. As another example, we first saturate one
part of aniline completely with perfectly dry and pure muriatic acid gas. The
resulting solid compound is then transferred into a glass or other suitable
vessel, provided with means for agitation, and by means of an oil bath raised
to a temperature of 380° F., or thereabouts, when it will assume a fluid state.
This temperature has to be maintained for one and half to two hours,
during which time are added in small portions two parts of perfectly dry and
finely powdered nitrate of lead. The mixture becomes very thick, and requires
constant stirring. At the end of the aforesaid time the action will be com-
plete, and the color is then extracted by treatment with boiling water, the
solution precipitated with common salt, and this precipitate dissolved, if
required, in alcohol, as before described.
We have mentioned under this second part of our Invention the use of
anhydrous nitrate of lead only, but other similar metallic salts, which will not
of themselves evolve the required colouring principle, may be employed, as, for
instance, nitrate of barium, sodium, &c.
Having thus described and ascertained the nature of our said Invention,
and the manner of carrying the same into effect, we deem it to be understood
that we claim as secured to us under the above in part recited Letters
Patent,-
Firstly, treating salts of aniline with solutions of perchloride of copper, or
with mixtures containing soluble salts of copper and alkaline chlorides.
Secondly, treating aniline with an anhydrous metallic nitrate, and an-
hydrous acids.
In witness whereof, we, the said John Dale and Heinrich Caro, have here-
unto set our hands and seals, this Twenty-third day of November in the
year of our Lord One thousand eight hundred and sixty.
JOHN DALE.
(L.S.)