AN IMPROVED PROCESS FOR OBTAINING PIGMENTS
Year: 1860

page_text: LETTERS PATENT to Thomas. Wontner Smith, of the Lower Road,.
Islington, in the County of Middlesex, Color Maker, for the Invention
Sealed the 3rd May 1861, and dated the 6th November 1860
PROVISIONAL SPECIFICATION left by the said Thomas Wontner Smith at
the Office of the Commissioners of Patents, with his Petition, on the
6th November 1860:
I, THOMAS WONTNER SMITH, of the Lower Road, Islington, in the County.
of Middlesex, Color Maker, do hereby declare the nature of the said Invention
for "AN IMPROVED PROCESS FOR OBTAINING PIGMENTS," to be as follows:-
The object of this Invention is so to operate upon the colors derived from
aniline as to produce a precipitate or pigment suitable for being used by paper--
stainers. To attain this end I first prepare a plastic compound by the
admixture of alumina and starch with water, and to this mixture I add the
liquid color as obtained in the market, by any of the well-known processes
used in preparing dyes from aniline; and I effect the thorough combination of
the color with the plastic compound by stirring the same well together or
passing the mixture through a grinding mill. When the compound has been
thoroughly mixed I leave it to rest for awhile, and thus obtain a precipitate..
I next remove the excess of water by filtration,, and obtain a pigment suitable
for block printing.

page_text: I would remark, that as alumina is used chiefly to give body to the color,
other substances having an earthy or metallic base may be used in lieu thereof,
if thought desirable; and in place of starch I have found that dextrine may be
used with advantage.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Wontner Smith, in the Great Seal Patent Office on
the 6th May 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WONTNER SMITH, of the Lower Road, Islington, in the County of Middlesex,
Color Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of November, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Wontner Smith, Her special license that I, the said Thomas
Wontner Smith, my exccutors, administrators, and assigns, or such others as I,
the said Thomas Wontner Smith, 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 "AN
IMPROVED PROCESS FOR OBTAINING PIGMENTS," upon the condition (amongst
others) that I, the said Thomas Wontner Smith, by an instrument in writing
under my hand and seal, 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 Thomas Wontner Smith, do hereby
declare the nature of my 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):-
The object of this Invention of "An Improved Process for Obtaining
Pigments," is to operate upon the colors derived from aniline or other
analogous products (obtained by the distillation and treatment of coal tar) in
such a manner as to produce a precipitate or pigment suitable for being used

page_text: by paper-stainers and others. To attain this end I first prepare a plastic
compound by the admixture of alumina and starch: with water, and to this
mixture I add the liquid color as obtained in the market by any of the well-
known processes used in preparing dyes or coloring matters from aniline or
other analogous substances; and I effect the thorough combination of the color
with the plastic compound by stirring the same well together or passing the
mixture through a grinding mill. When the compound has been thoroughly
mixed, I remove from the mixture by filtration any excess of water, and a
pigment suitable for printing or staining paper and other purposes will be the
result.
In carrying out my Invention, and applying the same to the production of
the pigment known as magenta lake, I first take, say, twenty-eight pounds of
alum produced by any of the known processes, and I dissolve it in a sufficient
quantity of hot water to hold all the alum.in solution when the liquor is cold.
The alumina is precipitated from the cold solution by means of a cold solution
of fourteen pounds of pearlash or ammonia, or soda of equal equivalents may
be used for the purpose. The precipitate thus obtained is then to be washed
with cold water and filtered until reduced to the consistency of thin paste. To
this paste I add twenty-eight pounds of starch, dextrine, fecula, or farina, or
some other suitable farinaceous, starchy, or glutinous vegetable substance pro-
duced or obtained in any convenient manner. I use by preference the white
starch obtained from wheat or rice. To this mixture, which must be well
stirred, I add eighteen pounds of the liquid coloring matter (red or purple)
obtained by any convenient process by the treatment of aniline.
It will, of course, be understood that the shade or intensity of the colour will
depend upon the proportions in which the liquid coloring matter is added, and
the above-mentioned proportion of eighteen pounds is therefore only given as
an example. The quantity may, however, be increased or diminished as may
be desired. The liquid coloring matter having been added to the mixture of
alumina and starch, I well stir the ingredients, and afterwards filter the same
until the mass is reduced to the state of a paste fit for use as a pigment; or,
the solid matters may be dried and ground to a powder. Starch, dextrine,
fecula, or other analogous vegetable substances may also be employed without
the alumina, and a lake may be produced from any of the solutions of aniline
colors or analogous substances by precipitating or assisting the precipitation of
the coloring matter by the addition with starch of a small quantity of a solu-
tion of a suitable salt of tin, preferring the muriate crystals; or vegetable
acids, such as citric or acetic acid may be employed to precipitate the coloring
matter, or assist in its precipitation by adding the acid to the starch. When

page_text: the precipitate has been obtained by the use of acids, a small quantity of liquid
ammonia or other weak alkali may be added for the purpose of increasing the
beauty of the color.
I would observe that instead of giving body to the pigment by the employ.
ment of alumina as a base, as above described, other substances, such as terra
alba, satin white, baryta, strontia, china clay, French chalk, or silicate of
magnesia, or a salt of tin, may be used in conjunction with the starch for
producing a lake.
Having now described my Invention of "An Improved Process for Obtaining
Pigments," and having explained the manner of carrying the same into effect,
I claim as the Invention secured to me by Letters Patent as aforesaid, the
mode or modes berein set forth of precipitating and preparing the coloring
matter obtained from aniline, or other analogous substances obtained by the
distillation of coal tar so as to render the same suitable to be used in the arts.
'In witness whereof, I, the said Thomas Wontner Smith, have hereunto
set my hand and seal, the Sixth day of May, in the year of our Lord
One thousand eight hundred and sixty-one.
THOS. WONTNER SMITH. (L.B.)