IMPROVEMENTS IN THE MANUFACTURE OF PRINTING INK AND OF BLACK AND OTHER PIGMENTS OR PAINTS."
Year: 1882

page_text: LETTERS PATENT to Carl Friedrich Claus of Mark Lane, in the City of
"
London, Chemist, for an Invention of IMPROVEMENTS IN THE MANUFACTURE
OF PRINTING INK AND OF BLACK AND OTHER PIGMENTS OR PAINTS."
PROVISIONAL SPECIFICATION left by the said Carl Friedrich Claus at
the Office of the Commissioners of Patents on the 28th August 1882.
CARL FRIEDRICH CLAUS, of Mark Lane in the City of London Chemist,
"IMPROVEMENTS IN THE MANUFACTURE OF PRINTING INK, AND OF BLACK AND
OTHER PIGMENTS OR PAINTS
"
This invention relates to the manufacture of printing ink and pigments or paints,
as herein described.
.
In practising the said invention I precipitate from solutions of iron in sulphuric
or hydro-chloric acid, by means of the sulphides of alkalies, or the sulphides of
alkaline earths, either sulphide of iron or mixtures of sulphide of iron and a
sulphate of an alkaline earth. I prefer to use for this purpose the sulphides of
barium or of strontium and as a source of solution of iron, I prefer to use the waste
liquors from tin plate works, galvanizing works, and, copper treating, and precipi-
tating works, which are at present run to waste and only serve to pollute the
rivers. If the sulphide of iron is precipitated from solutions of chloride of iron by
means of sulphide of barium I obtain, besides this precipitate, a solution of chloride
of barium, and if, by means of sulphide of strontium, I obtain a solution of chloride
of strontium I separate the solution from the precipitate by filtration, and I
evaporate and crystallize the chloride. The sulphide of iron thus precipitated is
intensely black; I filter this precipitate to as great a degree of dryness as is
practicable, and as the same (in a moist state) is rapidly oxidized, I heat it to drive
off the moisture, in closed vessels (provided with a small aperture to permit the
escape of steam) whereby I obtain the black pigment in a dry state. Or I mix the
same whilst moist intimately with the required vehicle such as linseed or other oil,
resin, resin soap, or solutions of resins in their respective solvents, or with solutions
of gum.

page_text: By this addition of oil, gum, or resins, or mixtures of these substances, the
precipitate becomes protected against the oxidizing action of the air. I then heat
the mixture, by steam or otherwise, to drive off the water retained by the oil, resin,
or gum, and then I grind the same to form either printing ink, black paint, blacking,
or other material according to the nature or the quantity of the vehicle used.
Once dry and protected from the air, the blackness remains unchanged. This is
also the case to a great extent when it has been dried in closed vessels, especially
in the presence of free sulphur as will be hereinafter explained.
I find it advantageous to carry on the precipitation of the sulphide of iron in
such a manner that some free sulphur is precipitated with it, and to employ such a
degree of heat in the driving off of the moisture that the free sulphur melts and
envelopes, as it were, in the molten condition, each particle of sulphide of iron and
thus protects it against oxidation. This result may be obtained by employing the
bi-sulphides or polysulphides of the alkalies or alkaline earths, and by the presence
of a per-salt of iron or free acid in the iron solution.
From the precipitate of sulphide of iron or the mixture of sulphide of iron and
the sulphate of an alkaline earth, I produce a superior yellow ochre by exposing the
said black precipitate to the oxidizing action of the air until every appearance of
black has disappeared from it. To hasten this change I dry the precipitate on an
open drying floor by a very slow moderate or low heat, which will not change the
ochre color to a red tint, or it may be produced by forming or moulding the pre-
cipitated sulphide of iron (when sufficiently stiff for the purpose) into bricks which
I dry and stack like common bricks. When dry I, grind the mass and it is then
ready for use.
By calcining the ochre, obtained in the manner above described, I obtain a
Venetian red of a superior quality. By varying the temperature employed in the
calcination a variety of shades and tints may be produced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Carl Friedrich Claus in the Great Seal Patent Office on the
28th February 1883.
CARL FRIEDRICH CLAUS of Mark Lane, in the City of London, Chemist.
"IMPROVEMENTS IN THE MANUFACTURE OF PRINTING INK, AND OF BLACK AND
OTHER PIGMENTS OR PAINTS."
This invention relates to the manufacture of printing ink and pigments or
paints.
In practising the said invention I precipitate from solutions of iron in sulphuric
or hydrochloric acid, by means of sulphides of alkalies or sulphides of alkaline
earths, either sulphide of iron or mixtures of sulphide of iron and sulphate of an
alkaline earth. I prefer to use as the precipitating agent for this purpose a
sulphide of barium or of strontium, and to obtain the solution of iron from the
waste liquors of tin plate works, galvanising works, or copper extracting and
precipitating works, which liquors at present only serve to pollute the rivers into
which they are discharged.
If the sulphide of iron is precipitated from a solution of chloride of iron, by
means of sulphide of barium, I also obtain therefrom a solution of chloride of
barium, and if the sulphide of iron is precipitated from such solution by means of
sulphide of strontium, I obtain at the same time a solution of chloride of strontium.
Í separate the solution from the precipitate by filtration, and I evaporate and
crystallize the chloride. The sulphide of iron thus precipitated is intensely black.
I filter this precipitate to as great a degree of dryness as is practicable, and as,
in a moist state, it is rapidly oxidized, I heat the same to drive off the moisture, in
closed vessels, (provided with a small aperture to permit the escape of steam.).
I thus obtain the black pigment in a dry state. Or I mix the precipitate, whilst
moist, intimately with a vehicle, such as linseed or other oil, resin, resin-soap or
solutions of resin in non-volatile solvents, or with solutions of gum, according to
the purpose for which it is to be used. By this addition of oil, resin, or gum, or
mixtures of these substances, the precipitate will be enveloped thereby and
protected against the oxidizing action of the air.
I then heat the mixture by steam or otherwise to drive off the water retained by
the oil, resin, or gum, and then I grind the said mixture to render it suitable for
either printing ink, black paint, blacking, or for other purposes. When freed from
water and protected, by admixture with a suitable vehicle, from oxidation by the
air, the blackness of the pigment remains unchanged. This is also the case to a
great extent, when it has been dried in closed vessels, especially if dried in the
presence of free sulphur as will be hereinafter explained.
I find it advantageous to carry on the precipitation of the sulphide of iron in
such a manner that some free sulphur is precipitated with it, and to employ such a
degree of heat, in driving-off the moisture, that the free sulphur fuses or melts and
envelopes, as it were, in the molten condition, each particle of sulphide of iron and
thus protects it against oxidation. This result may be obtained by employing the
bisulphides or poly-sulphides of the alkalies or alkaline earths, and by the presence
of a per-salt of iron or free acid in the iron solution.
From the precipitate of sulphide of iron, or the mixture of sulphide of iron and
the sulphate of an alkaline earth, I produce a superior yellow ochre by exposing
the said black precipitate to the oxidising action of the air (for instance by forcing
air through the liquid which holds the precipitate in suspension) until every
appearance of black has disappeared from it, or I dry the precipitate by means of

page_text: heated air or otherwise on an open drying floor with a very slow, moderate, or low
heat, which will not change the ochre to a red tint or colour. When dry, I grind
the mass, and it is then ready for use. When the black precipitate is intended to
be converted into ochre, the separation of free sulphur by the means above
indicated should be avoided and only proto-salts of iron free from acid or per salt
should be employed for the production of the said precipitate.
By calcining the ochre, obtained in the manner above described, I obtain a
Venetian red of a superior quality.
By varying the temperature employed in the calcination a variety of shades and
tints may be produced.
I wish it understood that in the above description I use the term sulphides as
including the bisulphides and hydrosulphides of Barium Strontium and Calcium.
Having thus fully described my said invention and the manner of performing
the same, I wish it understood that I Claim.
First. The manufacture of a black paint or pigment by a process in which the
precipitate formed by the Action of salt of iron upon a sulphide of an alkali, or of
an alkaline earth, is enveloped in oil, resin, or gum or in fused or melted sulphur,
for the purpose specified.
Second. The obtaining of chloride of barium or chloride of strontium simulta-
neously with the production of such black pigment, when the latter is produced by
the action of a solution of sulphide of barium, or of strontium, upon a solution of
chloride of iron.
Third. The production of ochre from the black precipitate (formed by the action
of salts of iron upon a solution of a sulphide of an alkali or of an alkaline earth)
by exposing the said precipitate to atmospheric air as described.
In witness whereof I the said Carl Friedrich Claus have hereunto set my
hand and seal this twenty-fourth day of February in the year of our Lord
one thousand, eight hundred and eighty three.
CARL FRIEDRICH CLAUS. (L.S.)