IMPROVEMENTS IN OBTAINING PIGMENTS FROM DYE WOODS, AND IN THE APPLICATION OF A PIGMENT TO PRINTING PAPER HANGINGS
Year: 1857

page_text: LETTERS PATENT to Thomas Roberts and John Dale, of Manchester, in
the County of Lancaster, Manufacturing Chemists, for the Invention
of "IMPROVEMENTS IN OBTAINING PIGMENTS FROM DYE WOODS, AND IN THE
APPLICATION OF A PIGMENT TO PRINTING PAPER HANGINGS."
Sealed the 12th January 1858, and dated the 17th July 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Roberts and John
Dale at the Office of the Commissioners of Patents, with their Petition,
on the 17th July 1857.
We, the said THOMAS ROBERTS and JOHN DALE, of Manchester, in the
County of Lancaster, Manufacturing Chemists, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN OBTAINING PIGMENTS FROM DYE WOODS,
AND IN THE APPLICATION OF A PIGMENT TO PRINTING PAPER HANGINGS," to be as
follows:-
Our Invention relates to obtaining pigments from dye woods, such as bar-
wood, sandalwood, camwood, &c., and the principle we proceed upon is, to
immerse them in a fluid containing a substance or substances which will take
up the coloring matter as it is dissolved. To illustrate this, we will suppose it
desired to obtain a pigment from barwood; for this purpose, the substance is
ground and then immersed in a fluid to which a salt of tin is added, the
coloring inatter then dissolves, and is taken up by the mordant, as it may be
called, and thus the process may be continued as long as may be desired.
Also our Invention consists in the use of the barwood itself as a pigment, for
which purpose it is ground sufliciently fine and immersed in any liquid which

page_text: will develope its tinctorial quality; this will be found to have taken place by
the use of the first part of our Invention, and the two may therefore be used
as a combined operation.
Also our Invention consists in the application of a pigment obtained from
barwood to the purpose of printing paper hangings, which pigment may be 5
obtained as above described, or by other means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Roberts and John Dale in the Great Seal Patent
Oflice on the 16th January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
ROBERTS and JOHN DALE, of Manchester, in the County of Lancaster, Manu-
facturing Chemists, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of July, in the year of our Lord
One thousand eight hundred and fifty-seven, in the
year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Thomas Roberts and John Dale, Her especial license that we, the said Thomas
Roberts and John Dale, our executors, administrators, and assigns, or such
others as we, the said Thomas Roberts and John Dale, our executors, adminis-
trators, 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 "IMPROVEMENTS IN OBTAINING PIGMENTS PROM DYE WOODS,
AND IN THE APPLICATION OF A PIGMENT TO PAINTING PAPER HANGINGS," upon the
condition, amongst others, that we, the said Thomas Roberts and John Dale,
or one of us, 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.
NOW KNOW YE, that I, the said Thomas Roberts, 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:-

page_text: Our Invention relates to obtaining pigments from dye woods, and the prin-
ciple we proceed upon is, to immerse them in a fluid containing a substance or
substances which will take up the coloring matter as it is dissolved.
Also our Invention consists in the use of barwood as a
pigment, and in the
application of a pigment obtained from barwood to the purpose of printing
paper bangings.
A method we adopt for carrying out the first part of our Invention is as
follows: Supposing it desired to produce a pigment from barwood; in a vessel
of wood or wood lined with lead and containing from five to six hundred
gallons of water we place about seven hundredweight of the ground or chipped
wood. In this vessel is a coiled pipe with perforations, through which steam
is blown so as to raise the fluid to the boiling point. This having been done,
fifty pounds of per-sulphate of tin are added, from which the oxide is precipi-
tated by the dilution, as is well understood by chemists; the whole is then
stirred, and the heat kept up for three or four hours, at the end of which time
coloring matter will have been extracted from the wood and taken up by the
oxide of tin, forming with it a bright red suitable for a pigment, but mixed
with particles of the ground or chipped wood; upon the fluid, however, being
kept still, the latter will fall first to the lower part of the vessel, and the super-
natant liquor containing the dyed oxide is drawn off into cisterns; it is then run
through sieves to separate any remaining particles of wood, and subsequently
washed, to free it from adhering acid resulting from the process, after which it
is run on to filters, and the retained pulp is fit for use for printing on cloth,
paper, or other substance, or for being otherwise applied as a pigment. If
desired, however, the pulp may be dried and used in that state as an article of
commerce.
We have above described a method of carrying out this part of our
Invention, which we have found to answer, but the quantities of the sub-
stances mentioned may be varied and the mode of using them modified; for
instance, the oxide of tin may be precipitated in a separate vessel or otherwise
obtained, and then added to the liquor in which the wood is placed. We have
also particularly alluded to barwood as affording the coloring matter, but we
in like manner use other suitable woods, particularly "red wood or red
sanders wood" and camwood." We would also observe, that although we have
mentioned the per-sulphate of tin as affording the mordaunt or vehicle for the
coloring matter, yet we do not confine ourselves thereto, for other salts of tin
or of other metals, the per-sulphate of iron, for instance, may be used in lieu
thereof, but the resulting color will of course vary, according to such altera-
tions. The wood remaining in the vessel above described will be found to bo

page_text: a colored material, and having been reduced by grinding or other ineans to
fine particles, is applicable, according to the second part of our Invention, as a
pigment for general purposes; the foregoing description, therefore, combines
two parts of our improvements, but, if desired, they may be used separately,
that is to say, the operation may be conducted for one result only; and in
reference to the pigment made from the wood itself, we do not limit ourselves
to the methods described, as other processes may be adopted for bringing out
the tinctorial qualities of the wood. In obtaining a pigment from barwood.
for the purpose of printing paper hangings, we extract the coloring matter
therefrom by treating it with alkaline solutions, as soda, potash, or amonia,
or salts; those which we prefer are the carbonates, borates, and stannates
of soda, potash, and amonia; other salts, however, possessing an alkaline
reaction may be used. In conducting this process we find that about one ounce
to one ounce and half of one of these dry salts to the gallon of water will afford
a liquor of sufficient strength, using about six hundred gallons to half a ton of
wood, and keeping it at the temperature of boiling water for about one hour.
The coloring matter so extracted is then added to oxide of tin or other oxide
or salt, according to the color required; and the pigment thus produced may
be modified in consistence by the addition of foreign substances, as chalk,
china clay, sulphate of barytes, &c.
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, obtaining pigments from dye woods by immersing them in a fluid
containing a substance or substances which will take up dissolved coloring
matter.
י
Secondly, the use of ground or similarly treated barwood as a pigment.
And, thirdly, the application of a pigment obtained from barwood, to the
purpose of printing paper hangings.
In witness whereof, I, the said Thomas Roberts, have hereunto set my
hand and seal, this Fifteenth day of January, in the year of our
Lord One thousand eight hundred and fifty-eight.
THO ROBERTS. (L.S.)