IMPROVEMENTS IN OBTAINING COLOURING MATTERS, PART OF WHICH IMPROVEMENTS, IS ALSO APPLICABLE TO DYEING
Year: 1863

page_text: LETTERS PATENT to Heinrich Caro, of Manchester, in the County of
Lancaster, Chemist, and John Dale, of the same Place, Manufacturing
Chemist, for the Invention of "IMPROVEMENTS IN OBTAINING COLOURING
MATTERS, PART OF WHICH IMPROVEMENTS, IS ALSO APPLICABLE TO DYEING AND
Sealed the 17th July 1868, and dated the 21st January 1863.
PROVISIONAL SPECIFICATION left by the said Heinrich Caro and John
Dale at the Office of the Commissioners of Patents, with their Petition,
on the 21st January 1863.
We, HEINRICH CARO, of Manchester, in the County of Lancaster, Chemist,
5 and JOHN DALE, of the same Place, Manufacturing Chemist, do hereby declare
.the nature of the said Invention for "IMPROVEMENTS IN OBTAINING COLOURING
MATTERS, PART OF WHICH IMPROVEMENTS IS ALSO APPLICABLE TO DYEING AND
PRINTING," to be as follows:-
Our Invention relates, firstly, to the use of acroleine for obtaining varied
O shades of colours from those colouring matters which are derived from
aniline.
In carrying out this part of our Invention we add acroleine to a solution
of the aforesaid aniline colours in a suitable solvent, as for instance, alcohol or
acetic or other acid, and we find that a change in the colours then takes place,

page_text: as, for instance, the reds become converted into purples, blues, and greens. In
like manner the purples are freed more or less from their red tinge.
By another method we modify the colour known as mauve. To effect
which we add to the said mauve benzoic acid, and aniline, and submit the
whole to heat, whereby the purple mauve becomes bluer in shade.
Another part of our Invention consists in applying the first-mentioned
improvement to the processes of dyeing and printing, in carrying out which we
take the dyed or printed article and apply to it a solution of acroleine, or we
take the fabric before it is dyed or printed and in like manner apply to it a
solution of acroleine.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Heinrich Caro and John Dale in the Great Seal
Patent Office on the 21st July 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRICH
CARO, of Manchester, in the County of Lancaster, Chemist, and JOHN DALE,
of the same Place, Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of January, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Heinrich Caro and John Dale, Her special license that we, the
said Heinrich Caro and John Dale, our executors, administrators, and assigns,
or such others as we, the said Heinrich Caro and John Dale, our 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, our Invention of " IMPROVEMENTS IN OBTAINING COLORING MATTERS,
PART OF WHICH IMPROVEMENTS IS ALSO APPLICABLE TO DYEING AND PRINTING," upon
the condition, amongst others, that we, the said Heinrich Caro and John
Dale, by an instrument in writing under our hands and seals, (or under the
hand and seal of one of us,) 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.

page_text: NOW KNOW YE, that I, the said Heinrich Caro, do hereby declare the
nature of our said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
Our Invention consists, firstly, in treating colours derived from aniline with
the substance known as acroleine, whereby the said colours become modified,
that is to say, those which were red, as, for instance, magenta and roseine, are
converted into purples, blues, and greens. In thus treating those colours
which are purple, as, for instance, mauve, the shade is in like manner caused to
assume a bluer tint. These changes we also effect upon goods which have
been dyed or printed with the aforesaid aniline colours by treating such goods
with a solution of acroleine. The proportions in which the substances are to
be combined, may be varied to a great extent, we will however give particulars
of certain combinations which will convey the necessary information for
carrying out our Invention. In order to obtain a soluble colouring matter
from aniline red suitable for dyeing, we make an acid solution thereof, and
then add the acroleine, and as an example in the following proportions, one
part by weight of crystallised magenta is dissolved in a cold mixture of ten
parts of water and twenty parts of sulphuric acid 1.84. s g. One half part
of acroleine is then gradually added, and the red dye is almost immediately
converted into a purple shade, by allowing the mixture to stand, say for twenty
or thirty minutes a blue is produced, and by a still longer action a green tint
is obtained. These changes may be hastened by the cautious application of
heat. The passage from one of these tints to another may be arrested at any
time by neutralizing the free acid contained in the mixture with caustic or
carbonated alkali, when the new or modified colouring matter is precipitated
ready to be used after the ordinary manner of dyeing or printing with aniline
colours. For treating mauve so as to modify its tint, the following proportions
of materials will be found to answer, one pound of dry mauve of aniline purple is
dissolved in two gallons of spirits of wine, and three pounds of sulphuric acid
1.84. s g, is then gradually added, after which two pounds of acroleine is
applied to the mixture. As in the former case the tint becomes modified
almost immediately, passing from purple through all shades towards blue, and
the action may be arrested at any desired period by the addition of an alkali
as before, the new coloring matter being in like manner precipitated ready
for use as a dye, and this treatment also applies to other purples such as
regina purple, violets, &c. By adding acroleine to a solution of magenta
containing only a slight quantity of acid, say one or two per cent., the whole
of the coloring matter is precipitated as a dark purple nearly insoluble, and

page_text: may be used as a pigment. In treating goods which have been dyed or
printed with the above named aniline colours we immerse them in a cold weak
solution of acroleine slightly acidulated, and allow them to remain until the
desired tint has been obtained, after which they are washed.
Another part of our Invention consists in treating mauve or aniline purple
with aniline and benzoic acid under heat whereby the tint is modified and a
blue coloring matter obtained. As an example of the proportions which may
be used we give the following:-Four parts of mauve and four parts of aniline.
are heated to about 300° F. and kept at that heat for about half an hour.
Then one part of benzoic acid is added, and the temperature gradually raised
to about 390° F. and kept in that condition for about two hours, the mass
thus obtained is boiled out repeatedly with weak muratic acid dried and
dissolved in spirits of wine and is then in a suitable condition for dyeing and
printing.
Having thus described and ascertained the nature of our said Invention and
the manner of carrying the same into effect we desire it to be understood, that
we claim as secured to us under the above in part recited Letters Patent.
Firstly, treating colouring matters derived from aniline with the substance
known as acroleine.
Secondly, treating goods dyed or printed with colours derived from aniline
with acroleine.
Thirdly, treating mauve or aniline purple with aniline and benzoic acid.
In witness whereof, I, the said Heinrich Caro, have hereunto set my
hand and seal, this Twentieth day of July, One thousand eight
hundred and sixty-three.
HEINRICH CARO. (L.B.)