Improvements in the Treatment of Oils and Essential Oils and particularly of Drying Oils.
Year: 1898

page_text: Date of Application, 15th Dec., 1898
Complete Specification Left, 6th Apr., 1899-Accepted, 6th May, 1899
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Oils and Essential Oils and
particularly of Drying Oils.
I, CHARLES DE LA ROCHE, of 6, Rue Gaston de Saint Paul, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the treatment of oils generally,
including essential oils, and more particularly of drying oils.
The process of this invention is based on the property possessed by carbide of
calcium of absorbing water and humidity. Thus vegetable oils, such as linseed
oil for example, are not really siccative until they have been subjected to a pro-
longed boiling at 360° which is the boiling point of the oil, at which temperature
the greater part of the moisture of the oil is evaporated and the mucilaginous
matters, which boiling is incapable of driving off, combine with the oleic acid in
consequence of the addition of litharge or manganese, to form a new product of a
very deep colour and really drying.
According to my invention I utilize the deliquescent properties of carbide of
calcium to take up the moisture contained in the oil without the aid of heat, a
precipitate of lime containing the water and mucilaginous matters held in sus-
pension in the oil, which prevent it from drying, being obtained.
From successive experiments made I am able to state that not only may the
so-called drying vegetable oils be thoroughly purified by this means, but that
the complete neutralization of oils, by the entire elimination of their acid elements
or ferments, may also be effected. The advantage possessed by this process of
dispensing with the use of heat in the first operation is that it enables the oil
to retain its natural colour, or is even less coloured and is undoubtedly more
brilliant than the normal oil.
The process as applied to the rectification of essential oils, particularly spirits
of turpentine has the advantage over all rectifying processes by distillation with
the aid of heat of entirely dispensing with the use of the latter and consequently
enabling the oils or spirits to retain their most volatile constituents and leave their
normal colouration unchanged. Moreover the essential oils now sold in commerce
are all more or less acid which can be readily proved by placing the oils even
cold in a copper vessel when a deposit of verdigris immediately forms thereon
accompanied by a greenish colouration of the liquid. By this process, however,
this acidity, whether of oils or essential oils, is neutralized by the lime resulting
from the decomposition of the carbide of calcium. Similarly as rewards the water
contained in all essential oils of commerce, unless they have been subjected to one
or two rectifications. By this process the moisture is completely eliminated, thus
enabling the cheap production, for making varnishes, of essential oils absolutely
free from water, which is a highly important advantage as will be recognized by
all connected with this branch of manufacture. The apparatus used for rectify-
ing essential oils are similar to those used for treating other oils.
A further result of the process is that linseed oil, for example, when treated in
the manner before described will dry in three days and remain absolutely as glossy

page_text: as a varnish while if it be raised to ebullition for an hour or two it will hardly
change colour, even if a certain proportion of manganese, litharge, or other oxide
be added for promoting drying, which then takes place in a few hours. The
advantage will be apparent to makers of oil varnishes, inasmuch as boiled and
drying linseed oil (treated by my process) when added to melted resin will not
increase the depth of colour but will diminish it; oil varnishes much less highly
coloured than those hitherto produced, can in this manner be obtained, which
constitutes one of the most important advantages of the invention.
For the purpose of this process I use as a hydro-extractor, an ordinary mixer
containing crude linseed oil to which is added about 10% of powdered carbide
of calcium, the mixture being stirred for about an hour, the acetylene produced
being disengaged and the carbide converting the oil into a greenish mixture due
to its conversion into lime which has absorbed the whole of the
moisture. It then only remains to let settle and decant, or
press in order to obtain a nearly colorless limpid, bright, drying oil free from all
inoisture or acidity. For boiling this oil the process is the same as for ordinary
oil, three to five per cent. of lead oxide or manganese being added during the
boiling.
even filter-
The filter-press cakes still contain unspent carbide which may be utilized for the
production of acetylene for lighting the works, by merely adding a little caustic
potash to the water in the vessel into which the cakes are thrown in order that
the fatty matters which isolate the carbide may be attacked and so enable it to
produce the acetylene and thus reduce by so much, the cost of treatment of the oils.
I have merely outlined the principle of the invention and may adopt such
improvements as experience may determine without departing from the invention.
The principal advantages obtained by my process are;-
(1) A considerable diminution of the colour of oil varnishes and a far superior
lustre, even when the oils used have been kept for several years in cellars;
(2) By the absence of all acidity these varnishes are no longer liable to become
cloudy or non-transparent and may be used immediately after their manufacture
the same advantages being also obtained in the manufacture of driers for dis-
temper colours and varnishes;
(3) Paint is prevented from cracking and a brilliancy is imparted to colours,
due to the purity of the oil which permits in many cases of dispensing with varnish-
ing which is a frequent cause of injury to works of art;
(4) It prevents paintings from becoming spotted or presenting dull patches;
(5) It prevents change of tone in colours produced by the too slow oxidation by
the air of crude oils containing acid and mucilaginous substances charged with
moisture;
(6) The oil when once hard, retains a gloss which enables it to be used in many 4
cases as a varnish, which is not liable to crack or to cause the cracking or deteriora-
tion of the colours on which it is applied as a protection against the action of the
air.
Improvements in the Treatment of Oils and Essential Oils and
particularly of Drying Oils.
I, CHARLES DE LA ROCHE, of 6, Rue Gaston de Saint Paul, Paris, France
Engineer, do hereby declare the nature of this invention and in what manner

page_text: the same is to be performed to be particularly described and ascertained in and
by the following statement;-
This invention relates to improvements in the treatment of oils generally,
including essential oils, and more particularly of drying oils.
The process of this invention is based on the property possessed by carbide of
calcium of absorbing water and humidity. Thus vegetable oils, such as linseed
oil for example, are not really siccative until they have been subjected to a pro-
longed boiling at 360° which is the boiling point of the oil, at which temperature
the greater part of the moisture of the oil is evaporated and the mucilaginous
matters, which boiling is incapable of driving off, combine with the oleic acid, in
consequence of the addition of litharge or manganese, to form a new product of a
very deep colour and really drying.
According to my invention I utilize the deliquescent properties of carbide of
calcium to take up the moisture contained in the oil without the aid of heat, a
precipitate of lime containing the water and mucilaginous matters held in sus-
pension in the oil, which prevent it from drying, being obtained.
From successive experiments made I am able to state that not only may the
so-called drying vegetable oils be thoroughly purified by this means, but that
the complete neutralization of oils, by the entire elimination of their acid elements
or ferments, may also be effected. The advantage possessed by this process of
dispensing with the use of heat in the first operation is that it enables the oil
to retain its natural colour or is even less coloured and is undoubtedly much
brighter than the normal oil.
The process as applied to the rectification of essential oils, particularly spirits
of turpentine has the advantage over all rectifying processes by distillation with
the aid of heat, of entirely dispensing with the use of the latter and consequently of
enabling the oils or spirits to retain their most volatile constituents and leave their
normal coloration unchanged. Moreover, the essential oils now sold in commerce
are all more or less acid which can be readily proved by placing the oils even
cold in a copper vessel when a deposit of verdigris immediately forms thereon
accompanied by a greenish coloration of the liquid. By this process, however,
this acidity, whether of oils or essential oils, is neutralized by the lime resulting
from the decomposition of the carbide of calcium. Similarly the water contained
in all essential oils of commerce (unless they have been subjected to one or two
rectifications) may by this process be completely eliminated, thus enabling the
cheap production for making varnishes, of essential oils absolutely free from water,
which is a highly important advantage as will be recognized by all connected
with this branch of manufacture.
The apparatus used for rectifying essential oils are similar to those used for
treating other oils.
A further result of the process is that linseed oil, for example, when treated in
the manner before described will dry in three days and remain absolutely as glossy
as a varnish while if it be raised to ebullition for an hour or two it will hardly
change colour, even if a certain proportion of manganese, litharge, or other oxide
be added for promoting drying, which then takes place in a few hours. The
advantage will be apparent to makers of oil varnishes, inasmuch as boiled and
drying linseed oil (treated by my process) when added to melted resin will not
increase the depth of colour but will diminish it; oil varnishes much less highly
coloured than those hitherto produced, can in this manner be obtained, which
constitutes one of the most important advantages of the invention.
For the purpose of this process I use as a hydro-extractor, an ordinary mixer
containing crude linseed oil to which is added about 10% of powdered carbide
of calcium, the mixture being stirred for about an hour, the acetylene produced
being disengaged and the carbide converting the oil into a greenish mixture due
to its conversion into lime which has absorbed the whole of the
moisture. It then only remains to let settle and decant, or even filter-
press in order to obtain a nearly colorless, limpid, bright drying oil, free from all

page_text: moisture or acidity. For boiling this oil the process is the same as for ordinary
oil, three to five per cent. of lead oxide or manganese being added during the
boiling.
The filter-press cakes still contain unspent carbide which may be utilized for the
production of acetylene for lighting the works, by merely adding a little caustic
potash to the water in the vessel into which the cakes are thrown in order that
the fatty matters which isolate the carbide may be attacked and so enable it to
produce the acetylene and thus reduce by so much, the cost of treatment of the oils.
It is to be understood that I have merely outlined the principle of the invention
and may adopt such improvements as experience may determine without departing
from the invention.
The principal advantages obtained by my process are: -
(1) A considerable diminution of the colour of oil varnishes and a far superior
lustre, even when the oils used have been kept for several years in cellars;
(2) Owing to the absence of all acidity, these varnishes are no longer liable to be-
some cloudy or non-transparent and may be used immediately after their manu-
facture, the same advantages being also obtained in the manufacture of driers for
distemper colours and varnishes:
(3) Paint is prevented from cracking and a brilliancy is imparted to colours,
due to the purity of the oil which permits in many cases of dispensing with varnish-
ing which is a frequent cause of injury to works of art;
(4) It prevents paintings from becoming spotted or presenting dull patches;
(5) It prevents change of tone in colours produced by the too slow oxidation by
the air of crude oils containing acid and mucilaginous substances charged with
moisture;
(6) The oil when once hard, retains a gloss which enables it to be used in many
cases as a varnish, which is not liable to crack or to cause the cracking or deteriora-
tion of the colours on which it is applied as a protection against the action of the
air.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
-
The herein described process of treating oils and volatile oils, and particularly
drying oils, which consists in mixing powdered carbide of calcium with the oil
in the cold state so as to form a precipitate of lime containing the water and
mucilaginous substances held in suspension, then letting settle and separating
the oil by decanting or filter-pressing so as to obtain a product free from moisture
and acid elements, substantially as specified.
That this ath Jos of 1000
A. M. & WM. CLARK,
Chartered Patent Agents
53, Chancery Lane, London.