Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
13334~
PROCESS FOR OVERBASED PETROLEUM OXIDATE
Field of the Invention
This invention relates to a method of preparing over-
based petroleum oxidates. More particularly, it relates
to a process for preparing an alkali or alkaline earth
metal overbased petroleum oxidate by carbonating the
petroleum oxidate in the presence of a solubilized alkali
or alkaline earth metal compound and to the overbased
petroleum oxidate prepared thereby. The overbased alkali
metal or alkaline earth metal petroleum oxidate can be an
overbased calcium petroleum oxidate, an overbased magne-
sium petroleum oxidate, or an overbased sodium petroleum
oxidate, as well as other overbased petroleum oxidates.
Ihe operation of diesel and spark ignition internal
combustion engines is typically accompanied by the forma-
tion of sludge, lacquer and resincus deposits which adhereto the moving engine parts and thereby reduce engine effi-
ciency. In order to prevent or reduce the formation of
these deposits, a wide variety of chemical additives has
been developed for incorporation into lubricating oils.
These additives, which are commonly referred to as deter-
gents or dispersants, have the ability to keep deposit-
forming materials suspended in the oil so that the engine
remains in a clean and efficient operating condition for
extended periods of time. Among the many additives which
have been developed for this purpose, certain alkaline
earth metal salts have been found to be highly effective
detergents for lubricating oils.
In addition to serving as highly efficient detergent
additives for lubricating oils, alkaline earth metal salts
are also excellent oxidation and corrosion inhibitors.
Further, these salts have the ability to neutralize acidic
combustion products which are formed during engine opera-
tion. The formation of these acidic products is a partic-
ular problem during engine operation with high sulfur
fuels. These acids appear to cause degradation of the
lubricating oil and are corrosive to metal engine compo-
nents such as bearings. If uncontrolled, the corrosion
--2--
induced by acidic combustion products can cause rapid
engine wear and a resulting early engine breakdown.
To further improve the ability of alkaline earth
metal salt additives to neutralize acidic combustion
products, these additives are commonly overbased.
Although overbased calcium and barium phenates and
sulfonates, among other salts, have been widely known and
used as detergents and sulfonates, overbased petroleum
oxidates and the easy ability to make and use highly over-
based petroleum oxidates have not been previously known.
The present invention is predicated on the discovery that
petroleum oils, oxidized in the presence of an amount of a
basic metal salt, such as metal hydroxides or, preferably,
an amount of an overbased petroleum oxidate of the same
composition as the overbased petroleum oxidate product,
can be overbased by carbonation in the presence of an
inorganic base. The carbonated overbased product of the
petroleum oxidate can be used directly in a lubricant for-
mulation as a rust inhibitor or as a lubricating oildetergent. In addition, the presence of petroleum oxidate
facilitates the carbonation process in the preparation of
overbased sulfonates, phenates and salicylates.
When petroleum oxidate is used as a modifier for pre-
paring overbased sulfonates, it has been discovered thatthe carbonation overbasing process is faster and more eco-
nomical than conventional methods. The overbased sulfo-
nate product of the carbonation is more stable under
conditions of prolonged heat and storage and is very clear
in appearance, without any or with little haze present,
thus adding to the product's market acceptance. Some-
times, the overbased sulfonates' Total Base Number (TBN)
is increased by using petroleum oxidate as an overbasing
modifier.
I 3334~8
--3--
Description of the Prior Art
The preparation of oxidized petroleum oils and their
use as detergents in lubricating oils is known in the art.
U.S. Patent No. 2,779,737 to Koft discloses the prep-
aration of calcium salts of oxidized petroleum oils by a
process which comprises the steps of oxidizing a petroleum
oil in the presence of calcium hydroxide and reacting the
product thus obtained with a calcium salt selected from
the group consisting of calcium chloride, calcium hypo-
chlorite and a mixture of calcium chloride and calcium
hydroxide in the presence of water. The oxidation step is
carried out at a temperature within the range of from
about 250~ to about 600P while passing air or oxygen
through the reaction mixture. By reacting the oxidation
product with a calcium salt, calcium content of the oxi-
dized oil product is increased from about 3 equivalents of
calcium in the oxidized product to about 3.35 to about
3.65 equivalents of calcium in the reacted product.
U.S. Patent No. 2,864,846 to Gragson discloses the
preparation of alkaline earth salts of oxidized petroleum
oils by a process which comprises the steps of oxidizing
petroleum oil with air in the presence of an oxidation
catalyst, preferably a P2S5-terpene reaction product, and
neutralizing the treatea oil with an alkaline earth
hydroxide or oxide.
U.S. Patent No. 2,895,978 to Brooks discloses a pro-
cess for oxidation of petroleum oils in the presence of
excess amounts of a metal hydroxide over and above that
which is eventually taken up by the oil during the oxida-
tion. The metal salts produced contain about 2 equiv-
alents of metal per equivalent of acid-hydrogen formed
during the oxidation.
U.S. Patent No. 2,975,205 to Lucki discloses a pro-
cess for preparation of metal salts of oxidized petroleumoils which comprises oxidizing petroleum oil in the pres-
ence of a metal hydroxide to incorporate the metal hydrox-
1~33 ~ ~
--4--
ide into the oil and then reacting the product obtainedwith more metal hydroxide in the presence of water to
incorporate an additional amount of metal hydroxide into
the product.
U.S. Patent No. 2,978,470 to Christensen discloses a
-- process for air oxidation of petroleum oils in the pres-
ence of a catalyst such as potassium permanganate or
potassium stearate. The oxidation is carried out until
the change has a saponification number of about 100 to
150.
Accordingly, although the oxidation of petroleum cils
to prepare a petroleum oxidate has been known, the prior
art neither teaches nor suggests the invented process com-
prising carbonation of a petroleum oxidate in the presenceof an inorganic base to produce a highly overbased petro-
leum oxidate, which is useful as a detergent, dispersant
and rust inhlbitor. Also, the prior art neither teaches
nor suggests that petroleum oxidate as a process modifier
improves overbasing processes for preparing overbased sul-
fonates, phenates and salicylates useful as lubricating
oil detergents and dispersants.
Summary of the Invention
A process is disclosed for preparation of novel
lubricant additives useful in lubricating oils and greases
comprising overbased alkali metal and alkaline earth metal
petroleum oxidates and for alkali metal and alkaline earth
metal oxidate-modified sulfonates, phenates and salicy-
lates with improved storage and heat stability.
1333~
-4a-
Further according to the present invention,
there is provided a process for carbonate overbasing
S of an alkali or alkaline earth metal sulfonate,
phenate or salicylate which comprises conducting said
carbonate overbasing of the sulfonate, phenate or
salicylate in the presence of a petroleum oxidate
overbasing modifier, said modifier being obtained by a
process comprising (a) introducing into a reaction
zone a petroleum oil and a base selected from the
group consisting of an alkali metal or alkaline earth
metal compound to form a mixture; and (b) contacting
said mixture with an oxidizing gas or compound at a
temperature from about -40F to effect oxidation of
said petroleum oil and reaction of said base with the
oxidized oil.
Detailed Description of the Invention
The invention comprises the method of overbasing an
oxidized petroleum oil to produce an overbased petroleum
oxidate and the products resulting from the overbasing
process. The term "overbased" is applied to designate the
presence of basic metal salts wherein the metal is present
1333~8
in stoichiometrically larger amounts than the organic acid
radical. The petroleum oil is oxidized by an oxygen-con-
taining gas or compound in the presence of a base. The
presence of a base is an essential element of the oxida-
tion process. The base can be insoluble, such as sodium
hydroxideJ but a soluble base such as an overbased sulfo-
nate is preferred. Air oxidation in the presence of an
overbased petroleum oxidate of calcium, magnesium or
sodium as catalyst is more preferred. Other overbased
petroleum oxidates of barium, potassium and strontium can
also be used. The resulting petroleum oxidate has a TBN
of about 1-10. The petroleum oxidate can be treated with
inorganic base and carbonated to yield a clear, overbased
oxidate of high TBN.
In another aspect of this invention, the petroleum
oxidate can be used to modify well-known processes used to
make overbased sulfonates and phenates. Such modification
with oxidate often results in process or product improve-
ments. Sodium, calcium and magnesium overbased petroleumoxidates are clear liquids useful as rust inhibitors, dis-
persants, detergents and friction modifiers. Sulfonates
overbased in the presence of petroleum oxidates have
improved rust inhibitor properties with a low sulfonate
soap content. Phenates overbased in the presence of
petroleum oxidates are semi-solid and solid materials with
lubricating properties as greases. Salicylates overbased
in the presence of petroleum oxidates also demonstrate
lubricant properties as grease materials.
A satisfactory feedstock for the invented process is
that prepared from topped crude oils obtained from any
source, for example, Pennsylvania, Mid-Continent, Califor-
nia, East Texas, Gulf Coast, Venezuela, Borneo and Arabian
crude oils. In this method, a crude oil is topped, i.e.,
distilled to remove therefrom more volatile and light gas
oil, and then vacuum-reduced to remove heavy gas oil and
light lubricating oil of the SAE-10 and 20 viscosity
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grade. The vacuum-reduced crude is then propane frac-
tioned to remove additional heavier fractions of lubricat-
ing quality hydrocarbons.
Following the propane fractionation step, the over-
head oil fraction is solvent-extracted with a selective
solvent which will separate the paraffinic hydrocarbons
from the more aromatic type hydrocarbons. This solvent
extraction step for the removal of the more highly aro-
matic compounds can be carried out in accordance with the
concurrent or countercurrent solvent extraction
techniques which are well known in the art.
The resulting solvent-extracted material, before or
after the removal of the more aromatic hydrocarbons, is
preferably dewaxed. The dewaxing can be carried out by
any conventional method, e.g., by solvent dewaxing using
propane or other known solvents and solvent mixtures such
as methylethylketone or methylisobutylketone with benzene
at a suitable temperature.
A preferred feed material for the oxidation reaction
is a substantially saturated hydrocarbon fraction having
at least 40 carbon atoms per molecule, preferably between
40 and 80 carbon atoms per molecule, a refractive index
nD20 of between 1.440 and 1.520, an average molecular
weight between 550 and 1300, a viscosity of between 50 and
1400 SUS at 210F, and a viscosity index, when determin-
able, of between 50 and 125.
The oxidizing reaction of the petroleum feed material
is accomplished in the presence of a basic catalyst by
contacting the selected hydrocarbon fraction, as hereinbe-
fore described, under suitable conditions of temperature
and pressure with an oxidizing agent such as free oxygen,
sulfur trioxide, nitrogen dioxide, nitrogen trioxide,
nitrogen pentoxide, acidified chromium oxide and chro-
mates, permanganates, peroxides, such as hydrogen perox-
ide, and sodium peroxide, nitric acid and ozone. Any
oxygen-containing material capable of releasing molecular
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oxygen under the conditions can be used. Air is a pre-
ferred oxidizing agent from the standpoint of economy.
Generally, the oxidation reaction is carried out at a
S temperature in the range from -40F to 800F. When air is
used as the oxidizing agent, temperatures in the range of
100F to 800F, preferably 390F to 575F, are generally
used. When nitric acid is used as the oxidation agent,
temperatures ranging from room temperature up to 200F,
preferably 140F to 170F, are ordinarily used.
The oxidation reaction can be carried out at sub-at-
mospheric, atmospheric or super-atmospheric pressure. The
reacticn is preferably carried out at a pressure of
between about 10 to 100 pounds per square inch absolute
depending upon the composition of the oxidizing gas.
A basic catalyst must be present during the oxidation
of the petroleum feed stock. An oxidation catalyst also
can be present to promote the oxidation reaction. The
oxidation catalyst can be selected from the group of well-
known oxidation catalysts such as oil-soluble salts and
compounds containing such metals as copper, iron, cobalt,
lead, zinc, cadmium, silver, manganese, chromium and vana-
dlum .
Any base may be used as the basic catalyst. It can
be soluble or insoluble. Typical basic catalysts includecalcium hydroxide, sodium hydroxide, overbased sodium,
calcium or magnesium sulfonate, or an overbased oxidate of
high TBN (one of the products of this invented process).
Powdered, insoluble catalysts such as calcium hydrox-
ide are inexpensive, but the oxidate must then be filteredto remove unreacted base. In order to eliminate the need
for this filtering step, it is preferred to use a homoge-
neous base, for example, a high-base calcium sulfonate.
Enough base must be used so that the total mass of oil and
base has a TBN of at least 2 before oxidation. There is
no upper limit to the amount of homogeneous base which can
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be used, but economically it is undesirable to use more
than 3~ of this component.
For example, if the basic catalyst is sodium hydrox-
ide, calcium hydroxide, 300 TBN calcium sulfonate, 400 TBN
magnesium sulfonate, or 400 TBN sodium oxidate, the mini-
- mum base levels necessary to yield a highly overbasable
oxidate would be 0.14%, 0.13%, 0.67%, 0.5~, or 0.5%,
respectively. Chemically, there is no upper limit for
these bases, but there are practical upper limits. For
the inexpensive insoluble bases such as sodium or calcium
hydroxide, unreacted base must be filtered, and it is con-
venient to limit the level of base to about 2-3%. For the
more expensive soluble bases such as overbased sulfonates,
2-3% is always adequate and can be described as the upper
practical limit. The use of very high levels of overbased
sulfonate as catalyst would thwart the very usefulness of
this invention, namely, a less expensive overbasing sub-
strate (soap) than sulfonate.
Since the product, high-base petroleum oxidate, of
the invented process is less expensive than high-base sul-
fonate, it is less costly to use the high base petroleum
oxidate as catalyst instead of high-base sulfonate. Homo-
geneous catalysts, such as high base calcium sulfonate,
have been used at levels of 1% to 3% in the base oil. The
resulting petroleum oxidate has a TBN of at least 2.
Although the oxidate can have a high TBN, the upper limit
should be about 12 TBN for economic reasons. Typical
petroleum oxidates will have TBNs of about 5-8.
Unexpectedly, it has been found that highly overbased
products [100 TBN and higher) can be made using these oxi-
dates as an inexpensive substrate instead of the usual
phenate, sulfonate, or salicylate. It has been discovered
that these oxidates can be used to facilitate overbasing
phenates and sulfonates to unexpectedly high TBNs not pre-
viously considered possible by conventional methods.
133',~
g
The oxidates prepared as described above can be over-
based by carbonating to clear, highly alkaline products.
The exact reason as to why clear, highly alkaline products
result from using petroleum oxidate as the substrate is
not known, but it is believed that the alkaline salts of
- Group I and Group II metals are finely dispersed by the
oxidate. The products have TBNs much higher than previ-
ously achieved, as taught in the prior art.
Unexpectedly, it has been found also that use of the
oxidate to prepare overbased sulfonate, phenate or salicy-
late products results in improved products over those pre-
pared by methods taught in the prior art. For example,
use of oxidate in overbasing magnesium sulfonate can
improve clarity of the product.
Unexpectedly, it has also been found that use of a
petroleum oxidate as the substrate in overbasing a sulfo-
nate by carbonation can result in an overbased product
with a low viscosity as compared with the viscosity of an
overbased sulfonate prepared without use of petroleum oxi-
date.
Examples of overbased sulfonates or carboxylates
which can be prepared with use of a petroleum oxidate
substrate are overbased aikali and alkaline earth metal
salts of sulfonic acids or carboxylic acids, typically
salts of sodium, potassium, lithium, calcium, magnesium,
strontium or barium prepared from sodium, potassium,
lithium, calcium, magnesium, strontium or barium sulfo-
nates, phenates or salicylates. The sulfonic acids can be
derived from petroleum sulfonic acids such as alkylbenzene
sulfonic acids. Examples of carboxylic acid salts pre-
pared with use of a petroleum oxidate substrate include
overbased phenates, both low-base phenates of TBN of
80-180 TBN and high-base phenates of about 250 TBN, and
salicylates, prepared by reacting alkali or alkaline earth
metal bases with alkyl salicylic acids. TBNs of so-pre-
1~3~
--10--
pared overbased salicylates can range from about 120 toabout 250.
The overbased sulfonates prepared by the process of
this invention are preferably magnesium, calcium or sodium
sulfonates. Magnesium sulfonates are preferably made from
- alkylbenzene sulfonic acids and typically will have a TBN
of about 400 with a sulfonate soap content of about 28%.
Calcium sulfonates preferably are from alkylbenzene sul-
fonic acids and typically will have TBNs ranging from300-400 with sulfonate soap contents ranging from about
20-30~. Sodium sulfonates preferably are made from a'kyl-
benzene sulfonic acids and typically will have TBNs of
about 400 and a soap content of about 18~. Low-base sul-
fonates prepared by the process of this invention are typ-
ically calcium sulfonate and preferably are made from
alkylbenzene sulfonic acids. These low-base sulfonates
typically will have TBNs of 15 to 40 and a soap content of
abcut 40~.
The commonly employed methods for preparing the basic
salts involves heatins a mineral oil solution of an acid
with a stoichiometric excess of a metal neutralizing agent
such as the metal oxide, hydroxide, carbonate, bicarbonate
or sulfide at a temperature about 50C and filtering the
resulting mass. The use of a "promoter" in the neutral-
ization step and the incorporation of a large excess of
metal likewise is known. Examples of compounds useful as
the promoter include phenolic substances such as phenol,
naphthol, alkylphenol, thiophenol, sulfurized alkylphenol,
and condensation products of formaldehyde with a phenolic
substance; alcohols such as methanol, 2-propanol, octyl
alcohol, Cellosolve, Carbitol, ethylene glycol, stearyl
alcohol, and cyclohexyl alcohol, amines such as aniline,
phenylenediamine, phenyl beta-naphthylamine
and dodecylamine. A particularly effective method for
preparing the basic salts comprises mixing an acid with an
excess of a basic alkaline earth metal neutralizing agent,
*Trade Marks
3~
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a phenolic promoter compound, and a small amount of water
and carbonating the mixture at an elevated temperature
such as 60-200C.
The overbasing process is carried out in the presence
of an organic solvent if more fluidity is desired. Such
- solvents can be benzene, toluene, xylene or raffinate,
among others.
The invented process for preparation of an overbased
alkali metal or alkaline earth metal petroleum oxidate
additive for lubricants with detergent, dispersant, anti-
rust and friction modifying properties accordingly com-
prises: (a) introducing into a reaction zone a petroleum
oil, (b) a base selected from the group consisting of an
alkali metal compound or an alkaline earth metal compound
to form a mixture, (c) contacting said mixture with an
oxidizing gas or compound at a temperature from about
-40F to about 800F to effect oxidation of said petroleum
oil and reaction of said base with the oxidized oil,
(d) optionally, filtering said mixture to separate the
base-reacted oxidized oil, (e) carbonating said base-
reacted oxidized oil in the presence of a base selected
from the group consisting of an alkali metal compound and
an alkaline earth metal compound to form a mixture com-
prising water and an overbased alkali metal or alkalineearth metal petroleum oxidate, (f) optionally filtering
said mixture to remove unreacted alkali metal compound or
alkaline earth metal compound, and (g) stripping said
overbased alkali metal or alkaline earth metal oxidate
additive to remove water.
The alkali metal compound or alkaline earth metal
compound for step (b) is selected from the group consist-
ing of the oxides, hydroxides and carbonates of sodium,
potassium, calcium, magnesium, barium and strontium.
The alkali metal compound or said alkaline earth
metal compound for steps (b) and (e) also can be selected
from the group consisting of oxides, hydroxides, carbo~
1~33~
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nates, sulfonates, phenates, salicylates and an overbased
petroleum oxidate. The alkali metal compound or alkaline
earth metal compound of step (b) also can be selected from
the group consisting of oxides, hydroxides and carbonates
of sodium, potassium, calcium, magnesium, barium and
strontium, and said alkali metal or alkaline earth metal
compound of step (e) can be selected from the group con-
sisting of sulfonates, phenates, salicylates, and an over-
based petroleum oxidate.
As an example, the process of the instant inventionfor preparing an overbased magnesium sulfonate comprises:
a) adding t~ a suitable vessel a charge mixture of
(1) about 30 to 90 parts by weight of ammonium sulfonate,
(2) about 50 to 120 parts by weight of No. 100 neutral
petroleum oil oxidized to petroleum oxidate, (3) about 100
to 400 parts by weight of xylene, and (4) about 25 to
about 60 parts by weight of magnesium oxide wherein said
magnesium oxide is added during mixing at ambient temper-
ature to about reflux temperature of said charge mixture;b) heating said charge mixture to about 100F wherein from
about 10 to about 35 parts by weight of methanol is added
and heating is continued up to about 140F wherein about
30 to 60 parts by weight of water is added, and the
resulting mixture is refluxed for up to 4 hours;
c) distilling said mixture to remove methanol, water and
xylene at a temperature of up to about 225F at ambient
pressure; d) cooling said mixture to about 100F and
thereupon carbonating said mixture with about 35 to about
90 parts by weight of carbon dioxide at a temperature of
from about 60F to about 200F until said mixture is satu-
rated; e) removing magnesium oxide impurities by centri-
fuge or filtration; and f) removing remaining xylene,
methanol and water by distillation at a reflux temper-
ature.
The following examples are illustrative of typicalembodiments of this invention and should not be considered
-13- 1 33~q ~
as limltlng the scope of the invented process and
composltlons.
Example I
The following example illustrates the preparation of
an oxidized calcium mineral oil which can be overbased to
yield oil-miscible alkaline agents.
A suitable vessel was charged with:
- 679 g Amoco Oil HX-40
- 21 9 high-base calcium
sulfonate (300 TBN )
- 10 ft.3/hr. air
The mixture was heated to a temperature of 400F for
4 hours. The product exhi~ited an activity of 68% on
silica gel with hexane as eluent in an elution column. It
needed no filtering because the basic catalyst was solu-
ble. It had a TBN of 7.
Example II
In the procedure of Example I, a sodium oxidate was
prepared. A suitable vessel was charged with:
- 980 9 Amoco Oil HX-40
- 20 9 400 TBN Sodium-Overbased Oxidate
(as prepared in Example V)
- 10 ft.3/hr. air
The mixture was heated to a temperature of 400F for
7.5 hours. Water collected overhead was 14 9. Light oil
collected in a dry ice condenser was 9 9. The product was
50% active on silica gel in an elution column using hexane
as the eluent. The product needed no filtering, and it
had a TBN of 6. The product could also be made using NaOH
as the basic catalyst, but then it would have to be fil-
tered to remove unreacted base.
*Trade Mark
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Example III
In the procedure of Example I, a magnesium oxidate
was prepared. A suitable vessel was charged with:
2,910 9 Amoco Oil HX-40
90 g high-base magnesium
sulfonate (400 TBN)
10 ft3 air/hr
The mixture was heated at 395F for 4 hours. The
product was 39~ active on silica gel in an elution column,
using hexane as the eluent. The product was clear without
filtration and had a T~N of 9.
Example IV
The product from Example I was overbased with calcium
as follows:
To a 2-liter, 3-neck round bottom flask fitted with a
heating mantle, reflux condenser, stirrer and dropping
funnel there was added 100 ml calcium oxidate from Exam-
ple I, 300 ml xylene, and 10 grams calcium oxide. The
mixture was then heated, and 5.5 grams of methanol were
added when its temperature reached 38C, and 0.9 grams of
water were added when its temperature reached 60C. neat-
ing was continued and the resulting mixture heated at
reflux (about 81C.) for 10 hours. A Dean Stark water
trap was placed between the reaction flask and the reflux
condenser. After cooling to 38C, the mixture was treated
with gaseous carbon dioxide which was introduced below the
surface of the reaction mixture at a rate of
.41 liter/minute over a period of 8 minutes while the
reaction mixture was maintained at a temperature of
38-46C. A total of 3.3 liters of carbon dioxide were
absorbed by the reaction mixture. The mixture was then
heated to 121C to remove water by way of a Dean Stark
water trap. Next, 10 grams calcium oxide, 0.9 grams water
and 5.5 ml methanol were added and the resulting mixture
carbonated with carbon dioxide for 9 minutes. An addi-
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tional 2.0 liters of carbon dioxide were absorbed.
Finally, the mixture was cooled to 100P and filtered.
The filtrate was nitrogen-stripped at a temperature of
about 360F to remove water and methanol.
The overbased calcium oxidate had a TBN of 120, a
- level of calcium oxidate overbasing not previously known
in the prior art. To my knowledge, use of petroleum oxi-
date as the substrate for overbasing to such a high TBN
was not taught or suggested in the prior art.
Although acidic substrates such as sulfonic acids,
phenols, carboxylates and other acidic compounds are
widely used to make overbased products and, although it
has long been known that mineral oils oxidize in the pres-
i5 ence of air at high temperatures, it has not been previ-
ously known that mineral oil can be oxidized to make clear
substrates which can be overbased to make highly (e.g.,
TBNs 100-500) alkaline agents suitable as rust inhibitors
or detergents.
Example V
The petroleum oxidate from Example II was overbased
with sodium as follows: To a 2-liter, 3-neck round bottom
flask fitted with a heating mantle, reflux condenser,
stirrer and dropping funnel there was added 100 grams
petroleum oxidate from Example II, 200 ml xylene and
370 grams of 20% NaOH in methanol. The mixture was
stirred and heated to about 225F, removing and condensing
the volatiies coming off as overhead. Then 16.8 liters of
carbon dioxide were introduced into the mixture at a rate
of 0.6 l/minute at a temperature of 225F. Carbonation
was then stopped, and the mixture was cooled to 100F and
filtered. The filtrate was then heated to about 360F and
nitrogen-stripped for a period of about 1 hour to remove
water and xylene. The resulting product was a clear,
amber viscous fluid and had a TBN of 413. To my know-
ledge, an overbased sodium oxidate with a high TBN has not
1333~
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been previously known, and the prior art does not suggest
the possibility.
Example VI
Petroleum oxidate from Example III was overbased with
- magnesium as follows: To a 2-liter, 3-neck round bottom
flash fitted with a heating mantle, reflux condenser,
stirrer and dropping funnel, there was added 65 grams of
magnesium petroleum oxidate from Example III, 100 grams
xylene, 20 srams magnesium oxide and 25 ml methanol. The
mixture was refluxed at a temperature of about 180F for a
period of about one minute. Water, 40 ml, was added and
the mixture was again refluxed at a temperature of about
220F for about one hour. The mixture was then nitrogen-
stripped at a temperature of about 280F for a period of
about 20 minutes to remove methanol which also removed
some water. The mixture was cooled to about 120F and
17 ml water was added. Carbon dioxide was introduced into
the mixture at a rate of 0.6 l/min. for a period of about
30 minutes. Approximately 5 liters of carbon dioxide were
absorbed. The mixture was cooled and filtered. The fil-
trate was nitrogen-stripped at 360F to remove water,
xylene and remaining methanol. The product, an overbased
magnesium oxidate, was a clear amber liquid with a TBN of
147. To my knowledge, overbased magnesium oxidates of
such high TBN have not been reported in the prior art.
Example VII
An overbased magnesium sulfonate oxidate was pre-
pared. To a suitable vessel there was added 30 grams
alkylbenzene sulfonic acid (mol-ecular weight 732),
16.1 grams SAE 20 base oil, 106.9 grams petroleum oxidate
prepared as in Example III, and 350 ml xylene. After
mixing and heating to 100F, ammonia gas was bubbled into
the mixture to neutralize the mixture. Magnesium oxide,
37 grams, with 17 ml of methanol was then added with stir-
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ring at a temperature of 100F. Temperature was raised to
reflux, approximately 180F, and 35 ml water was added
after which the mixture was refluxed for approximately one
hour. The mixture was nitrogen-stripped to a temperature
of about 280 F to remove volatiles comprising principally
methanol, but some water was also removed. The mixture
was allowed to cool to about 120F after stripping and
33 ml water was added. Carbon dioxide was introduced into
the mixture at a rate of 0.6 l/min. for a period of
25 ~,inutes. Eighteen liters of carbon dioxide were
absorbed. The mixture was allowed to cool to 100F and
was filtered. The filtrate was nitrogen-stripped to
remove solvent and water at a temperature of 360~. The
proa ;-t was a clear amber liquid, had a TB~ of 396 and
contained 13.2 (wt)% sulfonate soap. The product was
clear, neat and in benzene solution. Prior art does not
teach or suggest the preparation of an overbased magnesium
sulfonate cxidate with a TBN of 396 and a low level of
soap in a clear product.
Example VIII
Formulated oils containing the additives shown in
Table I were prepared and tested in a Sequence II D Test
Method. This procedure uses a 1977, 350 CID (5.7 liter)
Oldsmobile V-8 engine at moderate speed (1500 rpm) for
30 hours followed by a shutdown for 30 minutes and 2 hours
of high speed (3600 rpm) operation. The test is run with
leaded gasoline. The test measures the tendency of an oil
to rust or corrode the valve train. After the run, the
engine is disassembled and the condition of the valve
train is visually measured by trained operators against a
standard of 1 to 10. A 10 is no rust. The high-base mag-
nesium sulfonate oxidate prepared in Example VII was the
additive used. The control was a commercially available
magnesium sulfonate supplied by Amoco Petroleum Additives
*Trade Mark
1333~
-18-
Company, Clayton, Missouri. The sulfonate oxidate per-
formed well in the II D test.
Table I
Ex. VII
Mg
ControlSulfonate
Formulation (wt)%
Base Oil, 20 SAE 83.73 83.73
V.I. Im?rover 10.60 10.60
400 TBN Mg Sulfonate 1.00 0
400 TBN Mg S~lfonate Oxidate 0 1.00
Other Additives 4.67 4.67
100 . O 100 . O
II ~ Test Average Rust 8.07 8.73
Example IX
In this example, oxidate is used to facilitate the
carbonation process during overbasing to produce a 400 TBN
magnesiu;~ sulfonate. The overbasing process was similar
to that in Example VII, except for the amounts of raw
materials charged. The carbonation proceeded much more
smoothly in the run in which mineral oil was replaced by
oxidate.
Run 145A: 90 9 sulfonic acid blend
63 g Amoco Oil SX-5 mineral oil
Carbonation: 16 1 absorbed in
75 min, with CO2
supplied at 0.75 l/min
Run 147A: 90 9 sulfonic acid blend
63 9 oxidate prepared in the
method of Example III
1~33~88
--19--
Carbonation: 19 1 absorbed in only
35 min, with CO2
supplied at 0.75 l/min
Example X
Overbased alkali metal and alkaline earth metal sul-
fonates, phenates and salicylates, prepared wherein the
substrate is a petroleum oxidate, demonstrate improved
properties such as less haze.
The runs from Example IX provide an example of better
solubility (less haze) in overbased sulfonates modified
with oxidate.
Run 145A, control run: Haze in hexane = N
Run 1~7A, oxidate modified: Haze in hexane = F
Haze in hexane is defined as the haze of a solution con-
sisting of 5% test sulfonate and 95% hexane, as measured
on an Amoco Hazeometer. Range of haze values is from A
(clearest) to N (haziest).
Example XI
The influence of oxidate in modifying the carbonation
process can control the viscosity of the final overbased
products. The viscosity effect, accordingly, can be con-
trolled, depending upon the type of product that is
desired. The oxidate effect in Run 147A from Example IX
controls the viscosity of the product to produce an oil
additive for which a low viscosity is desired. The vis-
cosity of the control, Run 145A from Example IX, was veryhigh.
Run 145A, control run: 9,733 cSt at 100C
Run 147A, oxidate-modified: 85 cSt at 100C
Example XII
In some sulfonate overbasing processes, the presence
of oxidate increases the efficiency with which the avail-
~3~3~8
-20-
able metal is carbonated and incorporated into ~he prod-
uct. An example is the overbasing of calcium sulfonate by
the following process.
The following runs were made in a suitable vessel.
Runs 160-1 and 160-2 were controls. Run 160-3 was modi-
fied by using calcium oxidate, as produced in Example I,
to replace the SX-5 oil. Run 160-3 utilized over 30% more
lime than controls 160-1 and 160-2.
Run 160-1, control run
1) 64.3 9 ammonium sulfonate, 56% soap, 644 MW
108.8 g Amoco SX-S mineral oil
400 ml xylene
2) blow with ammonia
3) add 65 g CaO, 6 ml water, 35.4 ml methanol;
carbonate at 115-125F
4) add 24 g CaO, 2.2 ml water, 2.4 ml methanol;
carbonate at 115-125F
5) repeat step 4
6) strip to 195F, cool to 190 F, add 4 ml water,
stir 15 min
7) strip to 260F, filter, strip to 360F
Results: 31.3 liters of CO2 absorbed:
TBN = 331
Lime utilized = 36%
Control Run 160-2, repeat of Run 160-1
TBN = 334
-21-
Lime utilized = 37%
Run 160-3, oxidate-modified
34.4 1 CO2 absorbed
TBN = 408
- Lime utilized = 49%
The TBN of the oxidate-modified sulfonate, 408, was
approximately 22% greater than the TBN of the control sul-
fonate, 334, demonstrating the increased efficiency of
carbonating the oxidate-modified product.
