IMPROVEMENTS IN THE METHOD OF PURIFYING GUM (ROSIN OILS) OILS
Year: 1878

page_text: "E
LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Solicitors, at Frankfort-on-the-Main, in the Empire of Germany, for the
Invention of IMPROVEMENTS IN THE METHOD OF PURIFYING GUM (ROSIN
OILS) OILS." A communication from abroad by Werner Kelbe, Doctor of
Philosophy, of Carlsruhe, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 5th March 1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN THE METHOD
OF PURIFYING GUM (ROSIN OILS) OILS." [A communication from abroad by Werner
Kelbe, Doctor of Philosophy, of Carlsruhe, in the Empire of Germany.]
This Invention relates to improvements in the methods of purifiying resinous oils,
and consists, first, in turning the resin contained in the oil into a soapy matter by the
use of caustic soda, thus transforming the same into a substance soluble in water,
which can then be removed. A somewhat larger quantity of caustic soda than is
necessary to effect the said transformation serves to take up the phenol produced by
dry distilling.
It also comprises the operation of slowly simmering the washed oil in the air,
thus allowing the matters having an offensive odour and the phenol to evaporate,
thus also ultimately freeing the oil from those parts which give it a blue tinge,
this being effected by the oxidyzing influence of the air.
In carrying the said Invention into practice the oil is placed in a boiler provided
with a stirring apparatus, and heated to about 120 degrees Centigrade, then to every
100 lbs. oil 8 litres of soda solution of 1-215 specific gravity are stirred in; the oil upon
this becomes thick, but upou more soda being added clears again. The amount of
soda solution to be used depends on the quality of the oil. The gum soap produced

page_text: °
remains clear in the hot oil when containing a certain quantity of water; this water
is contained in the solution of soda of the strength named; at the same time it
occasions the solution of a small surplus of soda, thus causing a thorough mixing of
the latter with the oil. The mixture is then gently simmered for half an hour, the
water steamed off by this operation being replaced, and so regulated that the
mixture is always of a clear brown. If too much water is added the solution
divides from the oil; if, on the other hand, too little water is present, lumps of gum
soap separate from the oil, and are afterwards difficult to dissolve.
After half an hour of slow simmering, 50 litres of water are woll stirred into
every 100 lbs. of oil, and the liquid heated to a temperature of 50°-60° Centigrade;
it is then after a short stirring allowed to settle, care being taken that it remains
at the same temperature, because if the beat is too great the coloring matters become
separated, and are then taken up by the oil again. If allowed to be colder than
50° Centigrade the oil becomes too thick to separate from the solution. Too much
soda has the same effect at a too high temperature. The gum soap is precipitated
by a solution of salt. When the oil and solution have separated the latter is let off,
and the oil washed twice with, say, 25 litres of warm water. The oil is now thick
with suspended water, smells strongly, and has a blue tinge. In order to free it
from these qualities it is exposed to the air for some days at a temperature of 60°
-80° Centigrade, in flat iron vessels, and the volatile oils evaporate, and at the
same time the substances causing the blue tinge disappear.
The oil must not be exposed too long to the air, or made too hot, as in either of
these cases it becomes red. Oil manufactured in this manner is of a light yellow
color, has no smell, is not sticky, and has no blue tinge like the crude oil.
The sooner the oil is handled after distillation the lighter the color will be.
The soapy solution and the washing water are placed in a vessel and treated
with carbonic acid, causing the gum to run into lumps, when it can be redistilled
like new gum. The residue on being steaned off makes caustic soda.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 4th September
1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Maine, in the Empire of Germany. "IMPROVEMENTS IN THE
METHOD OF PURIFYING GUM (ROSIN ÔILS) OILS." A communication from Werner
Kelbe, Doctor of Philosophy, of Carlsruhe, in the Empire of Germany.
This Invention relates to an improved method of purifying resinous oils, and
consists, first, in converting the rosin contained in the oil into a soapy matter by
the use of caustic soda, thus transforming the same into a substance soluble in water,
which can then be removed. A somewhat larger quantity of caustic soda than is
necessary to effect the said transformation serves to take up the phenol produced by
dry distilling.
The said Invention also comprises the operation of slowly simmering the washed
oil in the air, thus allowing the matters having an offensive odour and the phenol
to evaporate, the oil being ultimately freed from those parts which give it a blue
tinge by the oxydizing influence of the air.
In carrying the said Invention into practice the oil is placed in a boiler provided with
a stirring apparatus, and heated to about 120° Centigrade; then to every 100 pounds
of oil 8 litres of soda solution of 1.215 specific gravity are added and stirred in; the
oil then becomes thick, but upon more soda being added clears again. The amount
of soda solution to be used depends on the quality of the oil. The gum soap
produced remains clear in the hot oil when containing a certain quantity of water;
this water is contained in the soda solution of the strength named at the same time
it causes the solution of a small surplus of soda, thus ensuring a thorough mixing of
the latter with the oil. The mixture is then gently simmered for half an hour, the
water steamed off by this operation being replaced, and so regulated that
the mixture is always of a clear brown. If too much water is added the solution
separates from the oil; if, on the other hand, too little water is present, lumps of
gum soap will separate from the oil, and will be afterwards difficult to dissolve.
After half an hour of slow simmering, 50 litres of wator are well stirred into every
100 pounds of oil, and the liquid heated to a temperature of 50° to 60° Centigrade,
it is then after a short stirring allowed to settle, care being taken that it remains at
the same temperature, because if the heat is too great the coloring matters become
separated, and are then taken up by the oil again. If allowed to be colder than 50°
Centigrade, the oil becomes too thick to separate from the solution. Too much soda
has the same effect at a too high temperature. The gum soap is precipitated by a
solution of salt. When the oil and solution have separated the latter is discharged,
and the oil washed twice with, say, 25 litres of warm water. The oil is now thick
with suspended water, smells strongly, and has a blue tinge. In order to free it
from these impurities it is exposed to the air for some days at a temperature of
60° to 80° Centigrade in flat iron vessels, and the volatile oils evaporate, and at the
same time the substances causing the blue tinge disappear.
The oil must not be exposed too long to the air, or made too hot, as in either of
these cases it becomes red. Oil manufactured in this manner is of a light yellow
colour, has no smell, does not become thick or gummy, and has no blue tinge like
the crude oil.
The sooner the oil is handled after the distillation the lighter the colour will be.
The soapy solution and the washing water are placed in a vessel and treated with
carbonic acid, causing the gum to run into lumps, when it can be redistilled like
new gum. The residue being evaporated will make caustic soda.

page_text: Having thus fully described the said Invention and the manner of performing
the same, I wish it understood that I claim,-
Treating the oil with a solution of caustic soda, as above described and for the
'purpose specified.
Also exposing the oil when under treatment to the influx of the atmospheric air,
as and for the purpose specified.
In witness whereof, I, the said Frank Wirth, bave hereunto set my hand
and seal, this Twenty-sixth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
TD TTZ
TDATT
וזה
FRANK WIRTH. (L.S.)