Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: LUBRICANT INCLUDING WATER DISPERSIBLE BASE
Field of Invention
Lubricants with excess basicity, characterized as total.base number (TBN)
are used as lubricants in internal combustion engines where atoms such as
sulfur,
nitrogen and carbon generate acidic combustion products that cause additional
wear.
In the past the overbased components where bases were reacted in the oil phase
with
gases like COZ contributed basicity. Water soluble or water dispersible bases
can
offer more neutralization capacity on a weight basis. The bases can be
incorporated
into an emulsified water phase.
Baclc~round of Invention
A variety of lubricant oils are available having various total base numbers.
One reason for having a total base number above zero in a lubricant is that
acidic
products are more likely to cause corrosion and wear to metal parts of a
device than
bases, which tend not to be involved in corrosion. Thus lubricants are
formulated
with sufficient excess base that over their intended lifetime, they remain
neutral or
slightly basic.
One particular use of a lubricant with a high total base number is in marine
diesel applications which economically burn residual fuels with a sulfur
content up
to about 4.5 weight percent. Due to the high amount of sulfur containing
species in
the economical residual fuel, the combustion products include high amount of
acidic
SOX which causes additional wear to the cylinder wall and the rings of the
piston. A
solution to this lubrication/corrosion problem caused by the SOX is to include
excess
base in the lubricant oil so that the SOX is converted to a metal salt of the
acid, which
has less tendency to cause corrosion or wear. In many marine diesel
applications
the cylinder oil is injected near the rings of the piston on a continual basis
to provide
both continued lubrication and replace the base lost to neutralization. In
these
applications the cylinder lubricant is continuously consumed rather than
returned to
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a sump. The marine diesel lubricant also needs good dispersancy, oxidative
stability
and antiwear properties.
Preparing basic complexes from oil soluble acids, bases, and acidic gases are
described in US patents 2,616,904; 2,616,905; 2,695,910; arid 2,739,125. These
patents typically attribute the ability to include high amounts of base in a
form
suitable for lubrication and stable against aggregation to complexes formed
with
various reaction procedures and promoters, sometimes including water and
sometimes not, and of the chemical reaction between the base and the COZ in
the oil.
They often quote a high basic metal content or ratio as an indication of
preparing a
useful complex.
GB 789,920 describes stable dispersions of inorganic metal compounds in
lubricating oil and methods of making the same. Such compositions possessing
increased detergency and increase reserve basicity find utility as additives
in
lubricating oils and possibly as corrosion inhibitors. The oils soluble
surface active
agents are typically sulfonates and the compositions include an aliphatic
alcohol
having less than six carbon atoms, which is removed. It appears that a mutual
solvent for the alcohol and the lubricating oil, such as benzene, is used to
form a
homogeneous mass that later separate into phases when the benzene and alcohol
are
removed.
Emulsions of water in oil have been described for use in hydraulic
applications such as in US Patents 3,269,946; 3,281,356; 3,311,561; and
3,378,494
where fire resistance was provided by the high water content of the fluid and
the use
temperature was low enough that the water of the water in oil emulsion was not
readily evaporated. Water in oil emulsions were generally not desired in
engine oils
as discussed in column 1 of US Patent 3,509,052, lines 41-55, where a
mayonnaise-
like sludge was observed in the rocleer arm covers and oil. fill caps of
smaller car
engines when moisture condensed from the air and was emulsified into the
engine
of 1.
Water in oil emulsions are also used as liquid fuels in some patent
applications such as US 4,002,435. A water in oil emulsion is described
therein
comprising a hydrocarbon, water, a water-soluble alcohol, and a novel
combination
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of surface-active agents to provide a clear fuel, which is stable against
phase
separation.
Summary of Invention
A lubricant having a total base number above 1 mg I~.OH/g is described. The
lubricant comprises a continuous oil phase, a discontinuous water phase (or
oil
insoluble solvent rich phase), and a base either dissolved or dispersed in the
water
(or oil insoluble solvent) phase. Optionally the water or oil insoluble
solvent can be
partially or fully removed in the final product. The base in the dispersed
(discontinuous) phase comprises at least a portion or all of the base in the
lubricating composition. Preferred bases include but are not limited to
calcium
hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, potassium
hydroxide, guanidine carbonate and sodium hydroxide. The bases described
herein
can be added by simple dissolution in a solvent and are not made by prior art
methods of chemically reacting at least two components within the oil phase
(in
situ). In marine diesel applications the total base number is desirably above
10 20,
or 30 mg I~OH/g.
The lubricant can also comprise various conventional lubricating additives to
assist in the performance of the lubricant such as dispersants, detergents
(including
neutral and overbased detergents), extreme pressure agents, antioxidants,
viscosity
index modifiers, etc. The lubricating oil can be selected from a wide variety
of oils
of API Groups I through V including mineral oils or combinations of grades or
synthetic or combinations with synthetics. A preferred use of the lubricant is
as a
cylinder lubricant in a marine diesel engine which can burn high sulfur
content fuels.
The high total base number of the lubricant can minimize the corrosive effect
of
sulfuric acid on the metal parts of the marine diesel engine. The lubricant
can be
used in a variety of other applications, such as an internal combustion engine
using
low sulfur fuel, where an oil with some basicity is beneficial to avoid the
effects of
acidic reaction products or to extend the useful life of the lubricant.
Brief Description of the Drawings
Figure 1 is a plot of the total base number of the drain oils in a marine
diesel
engine as a function of time for the three different cylinders in the same
engine.
Figure 2 is a plot of the total acid number of the drain oils. Figure 3 is a
plot of the
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Fe content as a function of time. Figure 4 is an illustration of the equipment
for the
hot-bar and high temperature neutralization test for oils.
Detailed Description of the Invention
Lubricating oils having increased basicity due to a dispersed base therein are
described. The base is typically added as dissolved or dispersed base in water
or
other oil insoluble solvent. The water or other oil insoluble solvent is then
dispersed
as a water or solvent in oil emulsion using the lubricating oil as the
continuous
phase. The water or oil insoluble solvent can remain or can be partially or
fully
removed. An emulsifiers) is used to colloidally stabilize the dispersions.
These
resulting oils can be used over a variety of temperature ranges including use
in the
combustion chamber of an internal combustion engine. The use of bases soluble
or
dispersible in water or other oil insoluble solvents within oil has been
limited in the
past due to the limited solubility of these compounds in hydrocarbon oils. The
use
of water or other oil insoluble solvents) emulsified in oil has been
discouraged
except for the use of water in oil emulsions for flame resistant hydraulic
fluids and
related lower temperature applications. Other oil insoluble solvents lilce
lower
alcohols and ethers have been avoided in lubricants for volatility reasons.
A major component to the lubricating oil is a base oil, hydrocarbon in most
situations although some synthetic oils that would not be strictly defined as
hydrocarbon could be used (e.g. esters and polyol esters). The word major is
used
because the amount of hydrocarbon based oil is often more than 50 weight or
volume percent but it need only be the continuous phase and can be as little
as 20 or
weight percent of the final formulation, depending on the application. In
marine
diesel application the hydrocarbon oil is typically more than 50 weight
percent of the
25 composition and often more than 75 weight percent of the composition.
Emulsifiers help emulsify the oil insoluble solvent e.g. water in the
hydrocarbon oil. The emulsifiers) can be any known emulsifier useful to
disperse
oil insoluble solvents e.g. water in oil. Preferably the emulsifiers include
one high
HLB (hydrophilic/lipophilic balance) emulsifier and/or one low HLB emulsifier.
30 The low HLB emulsifier can be an ester/salt made by reacting polyisobutenyl
succinic anhydride with ethylene glycol and dimethyl ethanol amine in an
equivalent
ratio of about 2:1:2. This emulsifier can have a high molecular weight
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polyisobutylene chain (~1500MW). The high HLB emulsifier can be an ester/salt
made by reacting hexadecyl succinic anhydride with dimethylethanolamine in an
equivalent ratio of about 1:1. It has a low molecular weight. The emulsifiers)
can
be present in any amount to effectively emulsify the water and water soluble
or
5 water dispersible base in the hydrocarbon oil phase. Preferred amounts of
emulsifier
include from about 0.5 to about 15 weight percent based on the weight of the
formulated lubricant.
Oil Insoluble Solvent
Water or another oil insoluble solvent or a blends) thereof is a necessary
component to the system. Water soluble organic materials or salts can be added
to
depress the freezing point of the water/solvent and/or to make the
waterlsolvent
more effective in dissolving or dispersing the base. While very pure water was
used
in some to the examples and is preferred since it would eliminate contaminants
that
might interfere with other additives or function, it is anticipated that water
with
various impurities could be used in marine diesel applications without any
significant disadvantages. Therefore water will include deionized water, tap
water,
recycled water, grey ship water, sea water, etc. Water can be up to 50 weight
percent of the formulated lubricant as long as it remains a dispersed phase
rather
than the continuous phase. Preferred amounts of water for marine diesel
applications are from about 5 to about 50 weight percent of the formulated
lubricant
and more desirably from about 5 to about 30 weight percent. Preferred amounts
of
water andlor oil insoluble solvents for lubricants for general internal
combustion
engines are from about l, 2, or 3 to about 10, 20 or 30 weight percent of the
formulated lubricant.
Oil insoluble solvents include Cl-C5 monohydric and polyhydric alcohols,
C2-C5 ethers and polyethers, and various other solvents that are not soluble
in SAE
paraffinic oils to an extent of 1g/100 ml of oil at 25 C. Ammonia and other
amines may be added to the water/solvent/blend to enhance one or more
properties
necessary of the solvent or of the final dispersion of base.
30 Base
A water soluble or water dispersible base is a necessary component to the
formulated lubricant. The base need not be a pure component but might be a
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mixture of several different bases or a partially neutralized base. One part
of the
base might be water soluble and the other part water dispersible. It is
desirable that
the base has minimal particulate material after dispersion having a dimension
between ten micron and a millimeter, these may be present in small amounts and
can
be filtered out if they become a problem .(either before or after emulsifying
the
particulate material) such a settling or become involved plugging lines or
orifices.
Typically bases that can be used include but are not limited to potassium,
sodium,
calcium, magnesium, lithium or aluminum hydroxide; potassium, sodium, calcium,
magnesium or lithium carbonate or bicarbonate; potassium, sodium, calcium,
magnesium, or lithium salts of Cl-CS organic acids; magnesium oxide; ammonia;
guanidine carbonate; urea; or combinations thereof. Guanidine carbonate and
urea
are desirable as they are considered as ashless additives and would be
expected to
decompose and yield ammonia or ammonia type bases upon exposure to elevated
temperatures. The base can be any water soluble nitrogen containing compound
that
would contribute basicity to the lubricating oil. These nitrogen containing
compounds would include the amines as defined as components of emulsifiers in
the
emulsifier's portion of this application along with salted version of those
amines e.g.
those amines reacted or partially reacted with mineral acids such as sulfuric
acid or
low molecular weight organic acids such as acetic acid or malefic acid. For
this
application it would be possible to also use the same amines coupled with
formaldehyde or polyalcohol such as tris(hydroxymethyl)aminomethane. The
nitrogen containing compound could also be a polyether amine e.g. a
poly(allceneoxide) of low or high molecular weight with one or more terminal
amine
groups. Preferred bases include NaOH, Ca(OH)Z, CaC03, KOH, or blends thereof.
MgO and Mg(OH)2 are desirable as some or all of the base in engine lubricant
applications where a high amount of vanadium is present in the fuels. They
minimize a vanadate problem associated with the vanadium. While KOH was used
in the examples other bases are just as preferred.
While the base can be present in almost any amount preferred ranges for
marine diesel applications include from about 0.5 to about 30 weight percent
based
on the weight of the formulated lubricant and more desirably from about 5 to
about
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30 weight percent. Preferred amounts of base for lubricants for general
internal
combustion engines are from about 0.1, 0.2, or 0.3 to about 10 or 30 weight
percent.
The formulated lubricant for marine diesel will desirably have a total base
number in excess of 10, 20, 30, 40, or 60 units where a unit is equivalent to
one
milligram of KOH/grarn of formulated lubricant. More desirably the lubricant
will
have a total base number between 20 and 100 or 150 and preferably between 40
and
100 or 150. Preferred TBN values for lubricants for general internal
combustion
engines are from about 1, 2, or 3 to about 10 or 20. Desirably the lubricant
will have
at least 50% of its total base number contributed by the base that was soluble
or
dispersible in water or other oil-insoluble solvent. Desirably in marine
applications
at least 10, 20, or 30 units of TBN will be attributable to the base added to
the
lubricant with an oil insoluble solvent (e.g. water). The remainder of the
total base
number may be provided by a variety of overbased oil soluble components such
as
overbased detergents that are still included in the composition.
The base added in this application will be dispersed, often as a dissolved
base, in an oil insoluble solvent (e.g. water) that is then emulsified in the
oil. The
dispersed phase can be present as a dispersed nanoparticle or micron sized
particle,
if the oil insoluble solvent has been removed. The base, or at least the
majority of
the base will not be solubilized into the oil on a molecular scale. Further
the base
component according to this invention will not be part of those overbased
metal
compounds described in patents such as US 2,626,904; 3,626,905; 3,695,910 or
2,739,125 where a first base is added to the oil along with an oil soluble
acid or
surfactant and then said base is chemically reacted with another chemical,
typically
a gas such as C02 or 502, to form another second different base in situ in the
oil
phase, said second base having different solubility or dispersibility in the
oil phase
due to the method of preparation and the presence of oil soluble acid or
surfactant.
The base component of this invention will be similar to the overbased metal
compounds in that desirably the ratio of equivalents of base to total
equivalents of
anionic groups on the surfactants will be above 2.5, more desirably above 5,
and
preferably above 10. Anionic groups on surfactants are well known and include
COO- and S03-. These high ratios are indicative that the base in not simply
being
carried as the counter ion to the surfactant groups. These overbased
components
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formed by in situ chemical reactions may be present as other functional
additives in
the lubricant and may be formed in trace amounts due to exposure of bases to
trace
C02 in the air.
As expressed above the bases added with the oil insoluble solvents, e.g.
water, generally have low oil solubility and thus are present in the dispersed
phase,
i.e. in the dispersed oiI insoluble solvents, or if the oil insoluble solvent
has been
partially or fully remove, the base can become the major or only component in
the
dispersed phase, stabilized as a colloidal dispersion by the emulsifier.
Dispersed
phases above 100 microns in any dimension are less preferred in colloidal
dispersions because they are harder to stabilize than smaller sized phases and
can
contribute to haziness. Dispersed phases above 20 microns in size tend to get
caught
in conventional engine oil filters. Dispersed phases below 5 manometers in
size
typically require significantly larger amounts of emulsifier than dispersed
phases of
50 or 500 manometers. Therefore, the dispersed phases of base and optional oil
insoluble solvent, e.g. water, desirably has a number average or intensity
average
particle size by light scattering of 5 manometers to 100 microns, more
desirably from
5 manometers to 20 microns, and preferably from about 10 manometers to about
10
microns.
Further the base in this application is not an alkali or alkaline metal borate
or
hydrated allcali or alkaline metal borate as described in US 3,853,772 and
related
patent documents on the use of borate compounds in lubricants.
Definitions
The term lower when used in conjunction with terms such as alkyl, alkenyl,
and alkoxy is intended to describe such groups that contain a total of up to 7
carbon
atoms.
The term water-soluble refers to materials that are soluble in water to the
extent of at least one gram per 100 milliliters of water at 25°C.
The term lubricant or hydrocarbon lubricant soluble refers to materials that
are soluble in a SAE 30 paraffinic base oil lubricant to the extent of at
least one
gram pen 100 milliliters of lubricant at 25°C.
A material which is less soluble in SAE 30 paraffin oil than lg/100mI, of oil
at 25°C will be classified as oil insoluble.
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Hydrocarbyl groups or substituents refers to a group having one or more
carbon atoms directly attached to the remainder of the molecule having a
hydrocarbon nature or predominantly so and includes 1) pure hydrocarbon groups
(e.g. alleyl, alkenyl, alleylene, and cyclic materials), 2) substituted
hydrocarbon
groups, which are still predominantly hydrocarbon in nature (e.g. halo,
hydroxyl,
alkoxy, mercapto, allcylmercapto, nitro, nitroso, and sulfoxy), and 3)
heterosubstituted hydrocarbon groups such as described in 2) with no more than
1 or
2 halogen, oxygen, sulfur, or nitrogen atoms or combinations per 10 carbon
atoms.
The Emulsifiers)
In one embodiment, the emulsifier used in accordance with the invention is
an emulsifier composition which comprises: (i) a hydrocarbon lubricant-soluble
product made by reacting a hydrocarbyl substituted carboxylic acid acylating
agent
with ammonia or an amine, the hydrocarbyl substituent of said acylating agent
having about 50 to about 500 carbon atoms; (ii) an ionic or a nonionic
compound
having a hydrophilic lipophilic balance (HLB) of about 1 to about 30; a
mixture of
(i) and (ii); or a mixture of (i) and (ii) in combination with (iii) a water-
soluble salt
distinct from (i) and (ii). Mixtures of (i), (ii) are prefen -ed. These
emulsifiers are
described in US Patent 6,383,237 hereby incorporated by reference (hereinafter
US
°237). This emulsifier composition is present in the lubricating oil
compositions of
the invention at a concentration of about 0.05 to about 20% by weight, and in
one
embodiment about 0.05 to about 10% by weight, and in one embodiment about 0.1
to about 5% by weight, and in one embodiment about 0.1 to about 3% by weight,
and in one embodiment about 0.1 to about 2.5% by weight. Emulsifiers have been
defined to distinguish them from overbased detergents and similar materials
even
though overbased detergents may have an effect on emulsion stability. It is
also
noted that dispersants, which are commonly used in lubricants, have some
similarity
to low HLB surfactants.
The hydrocarbyl-substituted carboxylic acid acylating agent for the
hydrocarbon lubricant-soluble product (i) may be a carboxylic acid or a
reactive
equivalent of such acid. The reactive equivalent may be an acid halide,
anhydride,
or ester, including partial esters and the like. The hydrocarbyl substituent
for the
carboxylic acid acyl.ating agent may contain from about 50 to about 300 or 500
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carbon atoms, and in one embodiment about 60 to about 200 carbon atoms. In one
embodiment, the hydrocarbyl substituent of the acylating agent has a number
average molecular weight of about 500 or 750 to about 3000, and in one
embodiment about 900 to about 2000 or 2300.
5 In one embodiment, the hydrocarbyl-substituted carboxylic acid acylating
agent for the hydrocarbon lubricant-soluble product (i) may be made by
reacting one
or more alpha-beta olefinically unsaturated carboxylic acid reagents
containing 2 to
about 20 carbon atoms, exclusive of the carboxyl groups, with one or more
olefin
polymers as described more fully hereinafter.
10 The alpha-beta olefinically unsaturated carboxylic acid reagents may be
either
monobasic or polybasic in nature. These are disclosed in US '237 column 13.
The olefin monomers from which the olefin polymers may be derived are
polyrnerizable olefin monomers characterized by having one or more ethylenic
unsaturated groups and they (monomers and polymers) are described in US '237
column 24.
These polyisobutylenes generally contain predominantly (that is, greater than
about 50 percent of the total repeat units) isobutene repeat units of the
configuration
CH3
-CH2-C
CH3
In one embodiment, the olefin polymer is a polyisobutene group (or
polyisobutylene group) having a number average molecular weight of about 750
to
about 3000, and in one embodiment about 900 to about 2000.
In one embodiment, the acylating agent for the hydrocarbon Iubricant-
soluble product (i) is a hydrocarbyl-substituted succinic acid or anhydride
represented correspondingly by the formulae
R-~H-COOH
H2-C~OH
or
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R
wherein R is hydrocarbyl group of about 50 to about 500 carbon atoms, and in
one
embodiment from about 50 to about 300, and in one embodiment from about 60 to
about 200 carbon atoms. The production of these hydrocarbyl-substituted
succinic
acids or anhydrides via alkylation of malefic acid or anhydride or its
derivatives with
a halohydrocarbon or via reaction of malefic acid or anhydride with an olefin
polymer having a terminal double bond is well known to those of skill in the
art and
need not be discussed in detail herein.
In one embodiment, the hydrocarbyl-substituted carboxylic acid acylating
agent for the product hydrocarbon lubricant-soluble product (i) is a
hydrocarbyl-
substituted succinic acylating agent consisting of hydrocarbyl substituent
groups and
succinic groups. The hydrocarbyl substituent groups are derived from an olefin
polymer as discussed above. The hydrocarbyl-substituted carboxylic acid
acylating
agent is characterized by the presence within its structure of an average of
at least
1.3 succinic groups, and in one embodiment from about 1.5 to about 2.5, and in
one
embodiment form about 1.7 to about 2.1 succinic groups for each equivalent
weight
of the hydrocarbyl substituent. In one embodiment, the hycliocarbyl-
substituted
carboxylic acid acylating agent is characterized by the presence within its
structure
of about 1.0 to about 1.3, and in one embodiment from about 1.0 to about 1.2,
and in
one embodiment from about 1.0 to about 1.1 succinic groups for each equivalent
weight of the hydrocarbyl substituent.
In one embodiment, the hydrocwbyl-substituted carboxylic acid acylating
agent is a polyisobutene-substituted succinic anhydride, the polyisobutene
substituent having a number average molecular weight of about 1500 to about
3000,
and in one embodiment about 1800 to about 2300, said first polyisobutene-
substituted succinic anhydride being characterized by about 1.3 to about 2.5,
and in
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one embodiment about I.7 to about 2.1 succinic groups per equivalent weight of
the
polyisobutene substituent.
In one embodiment, the hydrocarbyl-substituted carboxylic acid acylating
agent is a polyisobutene-substituted succinic anhydride, the polyisobutene
substituent having a number average molecular weight of about 700 to about
1300,
and in one embodiment about 800 to about 1000, said polyisobutene-substituted
succinic anhydride being characterized by about 1.0 to about 1.3, and in one
embodiment about 1.0 to about 1.2 succinic groups per equivalent weight of the
polyisobutene substituent. These are further described in US '237 columns 15
and
16.
The hydrocarbon lubricant-soluble product (i) may be formed using
ammonia and/or an amine. The amines useful for reacting with the acylating
agent
to form the product (i) include monoamines, polyamines, and mixtures thereof.
The rnonoamines have only one amine functionality whereas the polyamines
have two or more. The amines may be primary, secondary or tertiary amines. The
primary amines are characterized by the presence of at least one -NHZ group;
the
secondary by the presence of at least one H-N< group. The tertiary amines are
analogous to the primary and secondal-y amines with the exception that the
hydrogen
atoms in the -NHa or H-N< groups are replaced by hydrocarbyl groups.
Examples of primary and secondary monoamines are in US '237 column 16. The
amines may be hydroxyamines. The hydroxyamines may be primary, secondary or
tertiary amines. Typically, the hydroxyamines are primary, secondary or
tertiary
alkanolamines. The alkanol amines may be represented by the formulae:
H
~N-Rl-OH
H
H~
N-R~-OH
R
R N-R~-OH
R/
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wherein in the above formulae each R is independently a hydrocarbyl group
of 1 to about 8 carbon atoms, or a hydroxyl-substituted hydrocarbyl group of 2
to
about 8 carbon atoms and each R' independently is a hydrocarbylene (i.e., a
divalent
hydrocarbon) group of 2 to about 18 carbon atoms. These are further described
in
US '237 columns 16 and 17.
The amine may be an alkylene polyamine. Especially useful are the linear
or branched alkylene polyamines represented by the formula
HN-(Alkylene-N)"H
R R
wherein n has an average value between 1 and about 10, and in one embodiment
about 2 to about 7, the "Alkylene" group has from 1 to about 10 carbon atoms,
and
in one embodiment about 2 to about 6 carbon atoms, arid each R is
independently
hydrogen, an aliphatic or hydroxy-substituted aliphatic group of up to about
30
carbon atoms. These alleylene polyamines are described in US '237 column 18.
Ethylene polyamines are useful. In one embodiment, the amine is a
polyamine bottoms or a heavy polyamine. The term "polyamine bottoms" refers to
those polyamines resulting from the stripping of a polyamine mixture to remove
lower molecular weight polyamines and volatile components to leave, as
residue, the
polyamine bottoms. In one embodiment, the polyamine bottoms are characterized
as
having less than about 2% by weight total diethylene triamine or tl~iethylene
tetramine. These are described in US '237 column 18.
The hydrocarbon lubricant-soluble product (a) may be a salt, an ester, an
amide, an amide, or a combination thereof. The salt may be an internal salt
involving residues of a molecule of the acylating agent and the ammonia or
amine
wherein one of the carboxyl groups becomes ionically bound to a nitrogen atom
within the same group; or it may be an external salt wherein the ionic salt
group is
foamed with a nitrogen atom that is not part of the same molecule. In one
embodiment, the amine is a hydroxyamine, the hydrocarbyl-substituted
carboxylic
acid acylating agent is a hydrocarbyl-substituted succinic anhydride, and the
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resulting hydrocarbon lubricant-soluble product (i) is a half ester and half
salt, i.e.,
an ester/salt. These reactions to form these products are in US '237 in column
17.
Component (i)(b) is a hydrocarbon lubricant-soluble product made by
reacting an acylating agent with at least one ethylene polyamine such as TEPA
(tetraethylenepentamine), PE~iA (pentaethylenehexaamine), TETA
(triethylenetetramine), polyamine bottoms, or at least one heavy polyamine.
The
ethylene polyamine can be condensed to form a succinimide. The equivalent
ratio
of the reaction for CO:N is from 1:1.5 to 1:0.5, more preferably from 1:1.3 to
1:0.70,
and most preferably from 1:l to 1:0.70, wherein CO:N is the carbonyl to amine
nitrogen ratio. Also, component (i)(b) is preferably made from a
polyisobutylene
group having a number average molecular weight of from about 700 to about 1300
and that is succinated in the range from 1.0 up to 1.3.
The reaction between the hydrocarbyl-substituted carboxylic acid acylating
agent and the ammonia or amine is carried out under conditions that provide
for the
formation of the desired product which are set forth in US '237 column 17. .
In one
embodiment, the lubricant soluble product (i) comprises: (i)(a) a first
lubricant-
soluble product made by reacting a first hydrocarbyl-substituted carboxylic
acid
acylating agent with ammonia or an amine, the hydrocarbyl substituent of said
first
acylating agent having about 50 to about 500 carbon atoms; and (i)(b) a second
lubricant-soluble product made by reacting a second hydrocarbyl-substituted
carboxylic acid acylating agent with ammonia or an amine, the hydrocarbyl
substituent of said second acylating agent having about 50 to about 500 carbon
atoms. In this embodiment, the products (i)(a) and (i)(b) are different. For
example,
the molecular weight of the hydrocarbyl substituent for the first acylating
agent may
be different than the molecular weight of the hydrocarbyl substituent for the
second
acylating agent. In one embodiment, the number average molecular weight for
the
hydrocarbyl substituent for the first acylating agent may be in the range of
about
1500 to about 3000, and in one embodiment about 1800 to about 2300, and the
number average molecular weight for the hydrocarbyl substituent for the second
acylating agent may be in the range of about 700 to about 1300, and in one
embodiment about 800 to about 1000. The first hydrocarbyl-substituted
carboxylic
acid acylating agent may be a polyisobutene-substituted succinic anhydride,
the
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polyisobutene substituent having a number average molecular weight of about
1500
to about 3000, and in one embodiment about 1800 to about 2300. This first
polyisobutene-substituted succinic anhydride may be characterized by at least
about
1.3, and in one embodiment about 1.3 to about 2.5, and in one embodiment about
5 1.7 to about 2.1 succinic groups per equivalent weight of the polyisobutene
substituent. The amine used in this first lubricant-soluble product (i)(a) may
be an
alkanol amine and the product may be in the foi~rn of an ester/salt. The
second
hydrocarbyl-substituted carboxylic acid acylating agent may be a polyisobutene-
substituted succinic anhydride, the polyisobutene substituent of said second
10 polyisobutene-substituted succinic anhydride having a number average
molecular
weight of about 700 to about 1300, and in one embodiment about 800 to about
1000.
This second polyisobutene-substituted succinic anhydride may be chaa~acterized
by
about 1.0 to about 1.3, and in one embodiment about 1.0 to about 1.2 succinic
groups per equivalent weight of the polyisobutene substituent. The amine used
in
15 this second lubricant-soluble product (i)(b) may be an alkanol amine and
the product
may be in the form of an ester/salt, or the amine may be an allcylene
polyamine and
the product may be in the form of a succinimide. The lubricant-soluble product
(i)
may be comprised of: about 1% to about 99% by weight, and in one embodiment
about 30% to about 70% by weight of the product (i)(a); and about 99% to about
1%
by weight, and in one embodiment about 70% to about 30% by weight of the
product (i)(b).
In one embodiment, the lubricant soluble product (i) comprises: (i)(a) a first
hydrocarbyl-substituted carboxylic acid acylating agent, the hydrocarbyl
substituent
of said first acylating agent having about 50 to about 500 carbon atoms; and
(i)(b) a
second hydrocarbyl-substituted carboxylic acid acylating agent, the
hydl:ocarbyl
substituent of said second acylating agent having about 50 to about 500 carbon
atoms, said first acylating agent and said second acylating agent being the
same or
different; said first acylating agent and said second acylating agent being
coupled
together by a linking group derived from a compound having two or more p1-
imary
amino groups, two or more secondary amino groups, at least one primary amino
group and at least one secondary amino group, at least two hydroxyl groups, or
at
least one primary or secondary amino group and at Least one hydroxyl group;
said
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16
coupled acylating agents being reacted with ammonia or an amine. The molecular
weight of the hydrocarbyl substituent for the first acylating agent may be the
same
as or it may be different than the molecular weight of the hydrocarbyl
substituent for
the second acylating agent. In one embodiment, the number average molecular
weight for the hydrocarbyl substituent for the first and/or second acylating
agent is
in the range of about 1500 to about 3000, and in one embodiment about 1800 to
about 2300.
In one embodiment, the number average molecular weight for the
hydrocarbyl substituent for the first andlor second acylating agent is in the
range of
about 700 to about 1300, and in one embodiment about 800 to about 1000. The
first
andlor second hydrocarbyl-substituted carboxylic acid acylating agent may be a
polyisobutene-substituted succinic anhydride, the polyisobutene substituent
having a
number average molecular weight of about 1500 to about 3000, and in one
embodiment about 1800 to about 2300. This first and/or second polyisobutene-
substituted succinic anhydride may be characterized by at least about 1.3, and
in one
embodiment about 1.3 to about 2.5, and in one embodiment about 1.7 to about
2.I
succinic groups per equivalent weight of the polyisobutene substituent. The
first
and/or second hycli-ocarbyl-substituted carboxylic acid acylating agent may be
a
polyisobutene-substituted succinic anhydride, the polyisobutene substituent
having a
number average molecular weight of about 700 to about 1300, and in one
embodiment about 800 to about 1000. This first and/or second polyisobutene-
substituted succinic anhydride may be characterized by about 1.0 to about 1.3,
and
in one embodiment about 1.0 to about 1.2 succinic groups per equivalent weight
of
the polyisobutene substituent. The linlcing group may be derived from any of
the
amines or hydroxyamines discussed above having two or more primary amino
groups, two or more secondary amino groups, at least one primary amino group
and
at least one secondary amino group, or at least one primary or secondar y
amino
group and at least one hydroxyl group. The linking group may also be derived
from
a polyol. The polyol may be a compound represented in US '237 column 20.
The ratio of reactants utilized in the preparation of these linked products
may
be varied over a wide range. Generally, for each equivalent of each of the
first and
second acylating agents, at least about one equivalent of the linking compound
is
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17
used. The upper limit of linking compound is about two equivalents of linking
compound for each equivalent of the first and second acylating agents.
Generally
the ratio of equivalents of the first acylating agent to the second acylating
agent is
about 4:1 to about 1:4, and in one embodiment about I.S:1.
The first and second acylating agents may be reacted with the linking
compound according to conventional ester and/or amide-forming techniques. This
normally involves heating acylating agents with the linking compound,
optionally in
the presence of a normally liquid,,substantially inert, organic liquid
solvent/diluent.
The reaction between the linked acylating agents and the ammonia or amine
may be carried out under salt, ester/salt, amide or imide forming conditions
using
conventional techniques.
The hydrocarbon lubricant soluble product (r) may be present in the aqueous
hydrocarbon lubricant compositions of the invention at a concentration of
about 0.1
to about 15% by weight, and an one embodiment about 0.1 to about 10% by
weight,
and in one embodiment about 0.1 to about 5% by weight, and in one embodiment
about 0.1 to about 2% by weight, and in one embodiment about 0.1 to about 1%
by
weight, and in one embodiment about 0.1 to about 0.7% by weight.
The ionic or nonionic compound (ii) has a hydrophilic Iipophilic balance
(FILB) in the range of about 1 to about 20 or 30, and in one embodiment about
4 to
about 15 or 20. Examples of these compounds are disclosed in McCutcheon's
Emulsifiers and I7eter_ents, 1998, North American & International Edition.
Pages
1-235 of the North American Edition and pages 1-199 of the International
Edition
are incorporated herein by reference for their disclosure of such ionic and
nonionic
compounds having an HLB in the range of about 1 to about 10 or 30. These are
set
forth in US '237 column 27. In one embodiment, the ionic or nonionic compound
(ii) is a poly(oxyalkene) compound. These include copolymers of ethylene oxide
and propylene oxide. In one embodiment, the ionic or nonionic compound (ii) is
a
hydrocarbon lubricant-soluble product made by reacting an acylating agent
having
about 12 to about 30 carbon atoms with ammonia or an amine. The acylating
agent
may contain about 12 to about 24 carbon atoms, and in one embodiment about I2
to
about 18 carbon atoms. These are set forth in US '237 column 27. The amine may
be any of the amines described above as being useful in malting the
hydrocarbon
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18
lubricant-soluble product (i). The product of. the reaction between the
acylating
agent and the ammonia or amine may be a salt, an ester, an amide, an imide, or
a
combination thereof.
In one embodiment, the ionic or nonionic compound (ii) is an ester/salt made
by reacting hexadecyl succinic anhydride with dimethylethanolamine in an
equivalent ratio (i.e., carbonyl to amine ratio) of about 1:1 to about 1:1.5,
and in one
embodiment about 1:1.35.
In one embodiment, the ionic or nonionic compound can be the reaction
product of a copolymer of an alpha olefin of 3 to 25 carbon atoms with malefic
anhydride reacted with an amine (as previously described). One such reaction
product would be a copolymer of octadecene with malefic anhydride that is
reacted
with triethylene- tetramine. It may be desirable to control crosslinlcing with
these
multifunctional reactants by having large amounts of carboxylic acids of lower
functionality and/or amines of lower functionality present to avoid forming an
insoluble product.
The ionic or nonionic compound (ii) may be present in the aqueous
hydrocarbon fuel compositions of the invention at a concentration of about
0.01 to
about 15% by weight, and in one embodiment about 0.01 to about 10% by weight,
and one embodiment about 0.01 to about 5% by weight, and in one embodiment
about 0.01 to about 3% by weight, and in one embodiment about 0.1 to about 1%
by
weight.
The water-soluble salt (iii) may be any material capable of forming positive
and negative ions in an aqueous solution that does not interfere with the
other
additives. These include organic amine nitrates, nitrate esters, azides,
nitramines,
arid nitro compounds. Also included are alkali and alkaline earth metal
carbonates,
sulfates, sulfides, sulfonates, and the like. Particularly useful are the
amine or
ammonium salts represented by the formula
kLG(NR3)y~y~ nXP_
wherein G is hydrogen or an organic group of 1 to about 8 carbon atoms, and in
one
embodiment 1 to about 2 carbon atoms, having a valence of y; each R
independently
is hydrogen or a hydrocarbyl group of 1 to about 10 carbon atoms, and in one
embodiment 1 to about 5 carbon atoms, and in one embodiment 1 to about 2
carbon
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19
atoms; Xp- is an anion having a valence of p; and k, y, n and p axe
independently
integers of at least 1. When G is H, y is 1. The sum of the positive charge
ky+ is
equal to the sum of the negative charge nXP-. In one embodiment, X is a
nitrate ion;
and in one embodiment it is an acetate ion. Examples include ammonium nitrate,
ammonium acetate, methylammonium nitrate, methylammonium acetate, ethylene
diamine diacetate, urea nitrate, urea, guanidinium nitrate, and urea
dinitrate.
Ammonium nitrate is particularly useful.
In one embodiment, the water-soluble salt (iii) functions as an emulsion
stabilizer, i.e., it acts to stabilize the aqueous hydrocarbon lubricant
compositions.
In one embodiment the water soluble salt may be present in the water-
lubricant emulsion at a concentration of about 0.001 to about 1 % by weight,
and in
one embodiment from about 0.01 to about 1% by weight. In many embodiments the
water soluble salt is absent or serves as a different component, such as the
water
soluble or water dispersible base.
Conventional Detergents
A detergent is an additive that reduces formation of piston deposits, for
example high-temperature varnish and lacquer deposits, in engines; it normally
has
acid-neutralizing properties and is capable of keeping finely divided solids
in
suspension. Most detergents are based on metal "soaps", that is metal salts of
acidic
organic compounds, these are sometimes referred to as surfactants.
Detergents generally comprise a polar head with a long hydrophobic tail, the
polar head comprising a metal salt of an acidic organic compound. The
detergents
in this invention can be low TBN (<200 mgKQH/g) in which the surfactants are
neutralized with base to foam metal soaps. Alternatively , they can be
overbased
detergents in which large amounts of a metal base are included by reacting an
excess
of a metal compound, such as an oxide or hydroxide, with an acidic gas such as
carbon dioxide to give an overbased detergent which comprises neutralized
detergent as the outer layer of a metal base (e.g. carbonate) micelle. The
overbased
detergents of this invention may have a TBN of at least 200, preferably at
least 250,
especially at least 300, such as up to 600.
Surfactants that may be used include sulfonates, phenates, sulfurized
phenates, salicylates, calixarates, salicylic calixanenes, glyoxylates,
saligenins,
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thiophosphonates, naphthenates, other oil-soluble carboxylates, or mixtures of
any
of these surfactants. Sulfurized phenates are preferred. The metal may be an
alkali
or alkaline earth metal, e.g., sodium, potassium, lithium, calcium, and
magnesium.
Calcium is preferred.
5 Sui-Factants for the surfactant system of the overbased metal compounds
preferably contain at least one hydrocarbyl group, for example, as a
substituent on
an aromatic ring. The term "hydrocarbyl" as used herein means that the group
concerned is primarily composed of hydrogen and carbon atoms and is bonded to
the
remainder of the molecule via a carbon atom, but does not exclude the presence
of
10 other atoms or groups in a proportion insufficient to detract from the
substantially
hydrocarbon characteristics of the group. Advantageously, hydrocarbyl groups
in
surfactants for use in accordance with the invention are aliphatic groups,
preferably
alkyl or alkylene groups, especially alleyl groups, which may be linear or
branched.
The total number of carbon atoms in the surfactants should be at least
sufficient to
15 impart the desired oil-solubility.
These overbased salts can be of oil-soluble organic sulfur acids such as
sulfonic, sulfamic, thiosulfonic, sulfinic, sulfonic, partial ester sulfuric,
sulfurous
and thiosulfuric acid. Generally they are salts of carbocylic or aliphatic
sulfonic
acids.
20 The carbocylic sulfonic acids include the mono- or poly-nuclear aromatic or
cyeloaliphatic compounds. The oil-soluble sulfonates can be represented for
the
most part by the following formulae: °
~(Rll)X T~S~3)Y~zMb (
[RIZ-(SO3)a~dMU (XV)
In the above formulae, M is either a metal cation as described hereinabove or
hydrogen; T is a cyclic nucleus such as, for example, benzene, naphthalene,
anthracene, phenanthrene, diphenylene oxide, thianthrene, phenothioxine,
diphenylene sulfide, phenothiazine, diphenyl oxide, diphenyl sulfide,
diphenylamine, cycIohexane, petroleum naphthenes, decahydro-naphthalene,
cyclopentane, etc.; RI' in Formula XIV is an aliphatic group such as alkyl,
alkenyl,
allcoxy, alleoxyalkyl, carboalkoxyallcyl, etc.; x is at Least 1, and (R11)X T
contains a
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21
total of at least about 15 carbon atoms, R12 in Formula XV is an aliphatic
radical
containing at Least about 15 carbon atoms and M is either a metal ration or
hydrogen. Examples of the type of the R~2 radical are allcyl, allcenyl,
alkoxyalkyl,
carboalkoxyalkyl, etc. Specific examples of R~2 are groups derived from
petrolatum, saturated and unsaturated paraffin wax, and polyolefins, including
polymerized C~,, C3, C~, C5, C~, etc., olefins containing from about 15 to
7000 or
more carbon atoms. The groups T, R11 and R12 in the above formulae can also
contain other inorganic or organic substituents in addition to those
enumerated
above such as, for example, hydroxy, mercapto, halogen, nitro, amino, nitroso,
sulfide, disulfide, etc. Tn Formula XIV, x, y, z and b are at least l, and
likewise in
Formula XV, a, b and d are at least 1.
Specific examples of sulfonic acids useful in this invention are mahogany
sulfonic acids; bright stock sulfonic acids; sulfonic acids derived from
lubricating oil
fractions having a Saybolt viscosity from about 100 seconds at 100°F.
to about 200
seconds at 2I0°F.; petrolatum sulfonic acids; mono- and poly-wax
substituted
sulfonic and polysulfonic acids of, e.g., benzene, naphthalene, phenol,
diphenyl
ether, naphthalene disulfide, diphenylamine, thiophene, alpha-
chloronaphthalene,
etc.; other substituted sulfonic acids such as alkyl benzene sulfonic acids
(where the
allcyl group has at least 8 carbons), cetylphenol mono-sulfide sulfonic acids,
dicetyl
thianthrene disulfonic acids, dilauryl beta naphthyl sulfonic acid, dicapryl
nitronaphthalene sulfonic acids, and alkaryl sulfonic acids such as dodecyl
benzene
"bottoms" sulfonic acids.
The latter acids derived from benzene which as been alkylated with
propylene tetramers or isobutene trimers to introduce 1, 2, 3 or more branched-
chain
C12 substituents on the benzene ring. Dodecyl benzene bottoms, principally
mixtures of mono- and di-dodecyl benzenes, are available as by-products from
the
manufacture of household detergents. Similar products obtained from
alleylation
bottoms formed during manufacture of linear alkyl sulfonates (LAS) are also
useful
in malting the sulfonates used in this invention.
The production of sulfonates from detergent manufacture-by-products by
reaction with, e.g., 503, is well known to those skilled in the art. See, for
example,
the article "Sulfonates" in Kirk-Othmer "Encyclopedia of Chemical Technology,"
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22
Second Edition, Vol. 19, pp. 291 at seq. published by John Wiley & Sons, N.Y.
(1969).
Other descriptions of overbased sulfonate salts and techniques for making
them can be found in the following U.S. Patent Nos.: 2,174,110; 2,174,506;
2,174,508; 2,193,824; 2,197,800; 2,202,781; 2,212,786; 2,213,360; 2,228,598;
2,223,676; 2,239,974; 2,263,312; 2,276,090; 2,276,297; 2,315,514; 2,319,121;
2,321,022; 2,333,568; 2,333,788; 2,335,259; 2,337,552; 2,346,568; 2,366,027;
2,374,193; 2,383,319; 3,312,618; 3,471,403; 3,488,284; 3,595,790 and
3,798,012.
These are hereby incorporated by reference for their disclosures in this
regard.
Also included are aliphatic sulfonic acids such as paraffin wax sulfonic
acids, unsaturated paraffin wax sulfonic acids, hydroxy-substituted paraffin
wax
sulfonic acids, hexapropylene sulfonic acids, tetra-amylene sulfonic acids,
polyisobutene sulfonic acids wherein the polyisobutene contains from 20 to
7000 or
more carbon atoms, chloro-substituted paraffin wax sulfonic acids,
nitroparaffin wax
sulfonic acids, etc.; cycloaliphatic sulfonic acids such as petroleum
naphthene
sulfonic acids, cetyl cyclopentyl sulfonic acids, lauryl cyclohexyl sulfonic
acids, bis-
(di-isobutyl) cyclohexyl sulfonic acids, etc.
With respect to the sulfonic acids or salts thereof described herein and in
the
appended claims, it is intended that the term "petroleum sulfonic acids" or
"petroleum sulfonates" includes all sulfonic acids or the salts thereof
derived from
petroleum products. A particularly valuable group of petroleum sulfonic acids
are
the mahogany sulfonic acids (so called because of their reddish-brown color)
obtained as a by-product from the manufacture of petroleum white oils by a
sulfuric
acid process.
The terminology "metal ratio" is used to designate the ratio of the total
chemical equivalents of the metal in the overbased salt to the chemical
equivalents
of the metal in the salt which would be expected to result in the reaction
between the
organic acid to be overbased and the basic reacting metal compound according
to the
known chemical reactivity and stoichiometry of the two reactants. Thus, in a
normal
or neutral salt the metal ratio is one and, in an overbased salt, the metal
ratio is
greater than one. The overbased salts usually have metal ratios of at least
1.1:1.
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23
Typically they have ratios of 2:1 or 3:1 to 40:1. Salts having ratios of 12:1
to 20:1
are often used.
The basically reacting metal compounds used to make the overbased salts are
usually an alkali or alkaline eauth metal compound (i.e., the Group IA, IIA,
and IIB
metals, but normally excluding francium and radium and typically also
excluding
rubidium, cesium and beryllium), although other basically reacting metal
compounds can be used. Compounds of Ca, Ba, Mg, Na and Li, such as their
hydroxides and alkoxides of lower alkanols are usually used as basic metal
compounds in preparing these overbased salts but others can be used as shown
by
the prior art referred to herein. Overbased salts containing a mixture of ions
of two
or more of these metals can be used in the present invention.
Overbased materials are generally prepared by reacting an acidic material
(typically an inorganic acid or lower carboxylic acid, such as carbon dioxide)
with a
mixture comprising an acidic organic compound, a reaction medium comprising at
least one inert, organic solvent (mineral oil, naphtha, toluene, xylene, etc.)
for said
acidic organic material, a stoichiometric excess of a metal base, and a
promoter.
The acidic organic compound will, in the present instance, be the
functionalize allcyl
phenol.
The acidic material used in preparing the overbased material can be a liquid
such as formic acid, acetic acid, nitric acid, or sulfuric acid. Acetic acid
is
particularly useful. Inorganic acidic materials can also be used, such as HCl,
502,
503, C02, or H2S, and in one embodiment, CO2 or mixtures thereof, e.g.,
mixtures
of C02 and acetic acid.
A promoter is a chemical employed to facilitate the incorporation of metal
into the basic metal compositions. The promoters are diverse and are well
known in
the art and include lower alcohols. A discussion of suitable promoters is
found in
U.S. Patents 2,777,874, 2,695,910, and 2,616,904.
Patents specifically describing techniques for making basic salts of acidic
organic compounds generally include U.S. Patents 2,501,731; 2,616,905;
2,616,911;
2,616,925; 2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809;
3,488,284; and 3,629,109.
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Phenate surfactants for use in this invention, may be non-sulfurized or,
preferably, sulfurized. Further, phenate includes those containing more than
one
hydroxyl group (for example, from alkyl catechols) or fused aromatic rings
(for
example, alkyl naphthols) and those which have been modified by chemical
reaction, for example, alkylene-bridged and Mannish base-condensed and
saligenin
type (produced by the reaction of a phenol and an aldehyde under basic
conditions).
Preferred, phenols on which the phenate surfactants are based may be
derived from the formula I below:
s
Formula I
where R represents a hydrocarbyl group and y represents 1 to 4. Where y is
greater
than l, the hydrocarbyl groups may be the same or different
The phenols are frequently used in sulfurized form. Sulfurized hydrocarbyl
phenols
may typically be represented by the formula 11 below:
~a
Formula II
where x is generally from 1 to 4. In some cases, more than two phenol
molecules
rnay be linked by Sx, bridges.
In the above formulae, hydrocarbyl groups represented by R are
advantageously alkyl groups, which advantageously contain 5 to 100, preferably
5 to
40, especially 9 to 12, carbon atoms, the average number of carbon atoms in
all of
the R groups being at least about 9 in order to ensure adequate solubility in
oil.
Preferred alkyl groups are dodecyl (tetrapropylene) groups.
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In the following discussion, hydrocarbyl-substituted phenols will for
convenience be refereed to as alkyl phenols.
A sulfurizing agent for use in preparing a sulfurized phenol or phenate may
be any compound or element which Introduces -(S)x- bridging groups between the
5 alkyl phenol monomer groups, wherein x is generally from 1 to about 4. Thus,
the
reaction may be conducted with elemental sulfur or a halide thereof, for
example,
sulfur dichloride or, more preferably, sulfur monochloride. If elemental
sulfur is
used, the sulfurization reaction may be effected by heating the alkyl phenol
compound at from 50 to 250, preferably at least 100°C. The use of
elemental sulfur
10 will typically yield a mixture of budging groups -(S)X- as described above.
If a
sulfur halide is used, the sulfurization reaction may be effected by treating
the alkyl
phenol at from -10 to 120, preferably at least 60°C. The reaction may
be conducted
in the presence of a suitable diluent. The diluent advantageously comprises a
substantially inert organic diluent, for example mineral oil or an alkane. In
any
15 event, the reaction is conducted for a period of time sufficient to effect
substantial
reaction. It is generally preferred to employ from 0.1 to 5 moles of the alkyl
phenol
material per equivalent of sulphurizing agent.
Where elemental sulfur is used as the sulfurizing agent, it may be desirable
to use a basic catalyst, for example, sodium hydroxide or an organic amine,
20 preferably a heterocyclic amine (e.g., monpholine).
Details of sulfurization processes are well known to those skilled in the art.
Regardless of the manner in which they are prepared, sulfurized alkyl
phenols useful in preparing overbased metal compounds generally comprise
diluent
and unreacted alkyl phenols and generally contain from 2 to 20, preferably 4
to 14,
25 most preferably 6 to 12, mass % of sulfur, based on the mass of the
sulfurized alkyl
phenol.
As indicated above, the term "phenol" as used herein includes phenols which
have been modified by chemical reaction with, for example, an aldehyde, and
Mannich base-condensed phenols.
Aldehydes with which phenols may be modified include, for example,
formaldehyde, propionaldlehyde and butyraldehyde. The preferred aldehyde is
formaldehyde. Aldehyde-modified phenols suitable for use are described
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26
in, for example, US-A-5 259 967.
Mannich base-condensed phenols are prepared by the reaction of a phenol,
an aldehyde and an amine. Examples of suitable Mannich base-condensed phenols
are described In GB-A-2 121432.
In general, the phenols may include substituents other than those mentioned
above provided that such substituents do not detract significantly from the
surfactant
properties of the phenols. Examples of such substituents are methoxy groups
and
halogen atoms.
The functionalization of the alkyl phenol can comprise the addition of any
functional
group to the phenolic compound, other than an additional hydroxy group or an
additional hydrocarbyl group, at least one such alkyl or hydrocarbyl group
already
being present in sufficient amount to provide oil solubility to the detergent.
Typical
functional groups include t-butyl groups, methylene coupling groups, ester
substituted alkyl groups, and aldehyde groups. In one embodiment the
functionalization is by addition of carboxy functionality, in which case the
detergent
can be an alkyl salicylate or a derivative thereof. Salicylate detergents are
well
lrnown; see, for instance, U.S. Patent 5,65,751 or 4,627,925. In another
embodiment, the substituent can be based on a glyoxylic acid condensation.
Glyoxylic acid itself is HC(=O)-C02H; related. ketones of the structure
RiC(=O)-
CO~H are also contemplated; thus R' can be hydrogen or a hydrocarbyl group of,
for
instance, 1 to 20 carbon atoms. A typical glyoxylate condensation product is
shown
here as an anionic species, which will typically be neutralized with a metal
salt.
R R
In this structure, the R groups are alkyl groups. The material shown would be
the
condensation of 2 moles of alkyl phenol with 1 mole of glyoxylic acid or
derivative
thereof. Other molar ratios are also possible; when a 1:1 ratio is approached,
the
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27
condensation product becomes oligomeric or polymeric. These materials and
methods for their preparation are disclosed in greater detail in U.S. Patent
5,356,546.
In other embodiments the functionalized alleyl phenol can be a condensation
product of the allcyl phenol with formaldehyde or other lower aldehydes. The
acidic
substituent, in this case, would be considered to be the one or more
additional
phenolic groups. The simplest such condensation product would be
shown here as the 2:1 molar condensate of phenol:formaldehyde. Also, depending
on the conditions of reaction, the formaldehyde unit may appear in other
oxidation
states. As in the case of glyoxylates, oligomeric structures can be formed
when the
molar ratio of formaldehyde:phenol increases. Examples of such type of
oligomeric
species are the calixarates, which are cyclic materials containing 4 to ~
phenol-
formaldehye repeat units. Calixarates and methods of their preparation are
disclosed in greater detail in U.S. Patent 5,114,601. As will be apparent,
mixtures of
formaldehyde, other aldehydes, and glyoxylic acid can also be employed in such
condensation reactions.
One category of functionalized derivatives of alkyl phenols, however, is
certain saligenin derivatives. Saligenin itself, also known as salicyl alcohol
and o-
hydroxybenzyl alcohol, is represented by the structure
CHZOH
OH
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Useful saligenin derivatives include certain metal saligenin derivative which
function as detergents. When the metal is magnesium, these compounds can be
represented by the formula
o(Mg)n
X
k-p ~ Rir ~ m
This represents generally a metal salt, such as a magnesium salt, of a
compound
containing one aromatic ring or a multiplicity of aromatic rings linked by "Y"
groups, and also containing "X" groups. (Mg) represents a valence of a
magnesium
ion, and n, in each instance, is 0 or 1. (When n is zero the Mg is typically
replaced
by H to form an -OH group.) The value for "m" is typically 0 to 10, so nuimber
of
such rings will be 1 to 11, although it is to be understood that the upper
limit of "m"
is not a critical variable. In one embodiment m is 2 to 9, such as 3 to 8 or 4
to 6.
Other metals include alkali metals such as lithium, sodium, or potassium;
alkaline
earth metals such as calcium or barium; and other metals such as copper, zinc,
and
tin.
Most of the rings contain at Ieast one Rl substituent, which is the
aforementioned hydrocarbyl group, such as allcyl group. R1 can contain 1 to 60
carbon atoms, such as 7 to 28 carbon atoms or 9 to 18 carbon atoms. Of course
it is
understood that R1 will normally comprise a mixture of various chain lengths,
so
that the foregoing numbers will normally represent an average number of carbon
atoms in the Rl groups (number average). Each ring in the structure will be
substituted with 0, 1, 2, or 3 such R' groups (that is, p is 0, l, 2, or 3),
most typically
1, and of course different rings in a given molecule may contain different
numbers
of such substituents. At least one aromatic ring in the molecule must contain
at least
one R' group, and the total number of carbon atoms in all the R' groups in the
molecule should be at least 7, such as at least 12.
In the above structure the X and Y groups may be seen as groups derived
from formaldehyde or a formaldehyde source, by condensative reaction with the
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10
aromatic molecule. The relative amounts of the various X and Y groups depends
to
a certain extent on the conditions of synthesis of the molecules. While
various
species of X and Y may be present in the molecules in question, the commonest
species comprising X are -CHO (aldehyde functionality) and -CH20H
(hydroxymethyl functionality); similarly the commonest species comprising Y
are
-CH2- (methylene bridge) and -CHZOCH2- (ether bridge). The relative molar
amounts of these species in a sample of the above material can be determined
by
~H/13C NMR as each carbon and hydrogen nucleus has a distinctive environment
and produces a distinctive signal. (The signal for the ether linkage, -CH20CH2-
must be corrected for the presence of two carbon atoms, in order to arrive at
a
correct calculation of the molar amount of this material. Such a correction is
well
within the abilities of the person slulled in the art.)
In one embodiment, X is at least in part -CHO and such -CHO groups
comprise at least 10, 12, or 15 mole percent of the X and Y groups. In another
embodiment the -CHO groups comprise 20 to 60 mole percent of the X and Y
groups, such as 25 to 40 mole percent of the X and Y groups.
In another embodiment, X is at least in part -CHZOH and such -CH20H
groups comprise 10 to 50 mole percent of the X and Y groups, such as 15 to 30
mole percent of the X and Y groups.
In an embodiment in which m is non-zero, Y is at least in part -CHZ- and
such -CHZ- groups comprise 10 to 55 mole percent of the X and Y groups, such
as
to 45 or 32 to 45 mole percent of the X and Y groups.
In another embodiment Y is at least in part -CH20CH2- and such
-CHZOCHZ- groups comprise 5 to 20 mole percent of the X and Y groups, such as
25 10 to 16 mole percent of the X and Y groups.
The above-described compound is, as mentioned, typically a magnesium salt
and, indeed, the presence of magnesium during the preparation of the condensed
product is believed to be useful in achieving the desired ratios of X and Y
components described above. The number of Mg ions in the compound is
characterized by an average value of "n" of 0.1 to 1 throughout the
composition,
such as 0.2 or 0.3 to 0.4 or 0.5, or 0.35 to 0.45. Since Mg is normally a
divalent ion,
when all of the phenolic structures shown are entirely neutralized by Mg+2
ions, the
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average value of n in the composition will be 0.5, that is, each Mg ion
neutralizes 2
phenolic hydroxy groups. Those two hydroxy groups may be on the same or on
different molecules. If the value of n is less than 0.5, this indicates that
the hydroxy
groups are less than completely neutralized by Mg ions. If the value of n is
greater
5 than 0.5, this indicates that a portion of the valence of the Mg ions is
satisfied by an
anion other than the phenolic structure shown. For example each Mg ion could
be
associated with one phenolic anion and one hydroxy (OH-) ion, to provide an n
value
of 1Ø The specification that n is 0.1 to 1.0 is not directly applicable to
overbased
versions of this material (described below and also a part of the present
invention) in
10 which an excess of Mg or another metal can be present.
It is understood that in a sample of a large number of molecules, some
individual molecules may exist which deviate from these parameters, for
instance,
there may be some molecules containing no R' groups whatsoever. These
molecules
could be considered as impurities, and their presence will not negate the
present
15 invention so long as the majority (and generally the substantial majority)
of the
molecules of the composition are as described.
The above-described component can be prepared by combining a phenol
substituted by the above-described Rl group with formaldehyde or a source of
formaldehyde and magnesium oxide or magnesium hydroxide under reactive
20 conditions, in the presence of a catalytic amount of a strong base. Common
reactive
equivalents. of formaldehyde includes paraformaldehyde, trioxane, and formalin
.
For convenience, paraformaldehyde is can be used.
The relative molar amounts of the substituted phenol and the formaldehyde
can be important in providing products with the desired structure and
properties. In a
25 typical embodiment, the substituted phenol and formaldehyde are reacted in
equivalent ratios of 1:l to 1:3 or 1.4, such as 1:1.1 to 1:2.9 or 1:1.4 to
1:2.6, or 1:1.7
to 1:2.3. Thus in one embodiment there will be about a 2:1 equivalent excess
of
formaldehyde. (One equivalent of formaldehyde is considered to correspond to
one
H2C0 unit; one equivalent of phenol is considered to be one mole of phenol.)
30 The strong base can be sodium hydroxide or potassium hydroxide, and can
be supplied in an aqueous solution.
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The process can be conducted by combining the above components with an
appropriate amount of magnesium oxide or magnesium hydroxide with heating and
stirring. A diIuent such as mineral oil or other diluent oil can be included
to provide
for suitable mobility of the components. An additional solvent such as an
alcohol
can be included if desired, although it is believed that the reaction may
proceed more
efficiently in the absence of additional solvent. The reaction can be
conducted at
room temperature or at a slightly elevated temperature such as 35-
120°C, 70-110°C,
or 90-100°C, and of course the temperature can be increased in stages.
When water
is present in the reaction mixture it is convenient to maintain the mixture at
or below
the nounal boiling point of water. After reaction for a suitable time (e.g.,
30 rnmutes
to 5 hours or 1 to 3 hours) the mixture can be heated to a higher temperature,
typically under reduced pressure, to strip off volatile materials. Favorable
results are
obtained when the final temperature of this stripping step is 100 to about
150°C,
such as 120 to about 145°C.
Reaction under the conditions described above typically leads to a product
which has a relatively high content of -CHO substituent groups, that is,
10°70, 12%,
and even 15% and greater. Such materials, when used as detergents in
lubricating
compositions, exhibit good upper piston cleanliness performance, low Cu/Pb
corrosion, and good compatibility with seals. Use of metals other than
magnesium
in the synthesis typically leads to a reduction in the content of -CHO
substituent
groups.
Salicylate surfactants used in accordance with the invention may be non-
sulfurized or sulfurized, arid may be chemically modified and/or contain
additional
substituents, for example, as discussed below for phenates. Processes similar
to
those described below may also be used for sulfurizing a hydrocarbyl-
substituted
salicylic acid, and are well known to those skilled in the art. Salicylic
acids are
typically prepared by the carboxylation, by the Kolbe-Schmit process, of
phenoxides, and in that case, will generally be obtained (normally in a
diluent) in
admixture with uncarboxylated phenol.
Calixarates such as salixarenes i.e. salicylic calixarenes are also useful
compounds to add as surfactants to lubricating oils. Salicylic calixarenes
useful in
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32
this invention include those described in US Patent 6,200,93681 to the
Lubrizol
Corporation hereby incorporated by reference for its teachings.
Preferred substituents in oil-soluble salicylic, acids from which salicylates
in
accordance with the invention may be derived are the substituents represented
by R
in the discussion below of phenols. In alkyl-substituted salicylic acids, the
allcyl
groups advantageously contain 5 to 100, preferably 9 to 30, especially 12 to
20,
carbon atoms.
Oil of Lubricating ViscOSity
The lubricating oils used may vary significantly depending on the final use
of the oil. SAE 5 or 10 to about 70 are typical of the oils used in various
internal
combustion engines of various designs. Marine diesel applications typically
call for
the higher viscosity oils to provide a thicker lubricating film. While
multigrade oils
are desirable where the oil needs to provide lubrication at higher use
temperatures
along with low energy consumption at cold starting temperatures, marine diesel
applications tend to use a single grade oil because the engines are subject to
minimal.
cycling on and off and run for extended periods of time when operational. If a
multigrade oil is used, desirably it has a viscosity index of at least 90,
more desirably
at least 100 and preferably at least 110. Desirably the lubricating oil
basestock for
marine diesel applications has a kinematic viscosity at 100 C (as measured by
ASTM D445) of at least 14 centistokes, preferably at least 15 centistokes,
more
preferably in the range of from 17 to 30 centisokes, for example from 17 to 25
centistokes.
The lubricating oil can be any conventional oil or blends thereof used in
internal combustion engines for a lubricant. Often for cost reasons the oil is
a
petroleum derived lubricating oil (e.g. distillation products), such as a
naphthenic
base, paraffinic base or a mixed base oil. The lubricant depending on the
application
be a blend of petroleum derived oils and synthetic oils. Alternatively the
lubricating
oil may be a synthetic oil such as synthetic ester lubricating oils. Other
lubricating
oils that can be used are hydrocracked oils where the refining process further
breaks
down the middle and heavy distillate fractions in the presence of hydrogen.
Liquid
alpha olefin polymers may also be part or all of the lubricant. Fischer-
Tropsch oils
can be used in the lubricant. Brightstock, typically characterized as solvent-
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extracted, de-asphalted products from vacuum residuum, typically having a
lcinematic viscosity at 100 C of from 28- 36 centistokes may also be used.
The lubricant of the invention also can include conventional additives lilee
detergents, dispersants, viscosity modifiers, antioxidants, extreme pressure
additives
(antiwear additives), foam inhibitors, corrosion inhibitors, etc. that are
well lcnown
to the lubricant art. These additives can be used in conventional amounts.
In one embodiment, the lubricant of the invention contains an antifreeze
agent to prevent freezing of the water component. The antifreeze agent is
typically
an alcohol. Examples include but are not limited to ethylene glycol, propylene
glycol, methanol, ethanol, glycerol and mixtures of two or more thereof. The
antifreeze agent is typically used at a concentration sufficient to prevent
freezing of
the water used in the lubricant. The concentration is therefore dependent upon
the
temperature at which the lubricant is stored or used. In one embodiment, the
concentration is at a level of up to about 20% by weight based on the weight
of the
water-fuel emulsion, and in one embodiment about 0.1 to about 20% by weight,
and
in one embodiment about 0.2 to about 10% by weight.
As shown in the following examples the use of water soluble bases such as
KOH in a lubricating oil does not result in any significant instability
problems for
the bases when the temperature of the oil exceeds I00°C where the water
may be
evaporating at a fairly rapid rate and the total amount of water may be
significantly
less than the amount in the formulation.
Marine cylinder lubricants are used in marine engines including two stroke
marine engines in order to provide lubricity, antioxidancy, high temperature
detergency and neutralisation of sulphuric acid foamed during the combustion.
Traditional formulations use overbased detergents for acid neutralisation. The
following examples describe a water in lubricant oil emulsion, which uses KOH
dissolved in the water phase. KOH is a widely used and non-expensive base. KOH
could neutralise the acids formed during the combustion in a more efficient
way than
the overbased detergents, which would improve the efficiency of the marine
cylinder
lubricant and reduce the cost of the formulation. The examples also descl-ibe
the
emulsifiers used for the preparation of the water in oil emulsion. These
emulsifiers
could also contribute to the high temperature detergency.
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Examples
Water in oil emulsions containing ~20 %w/w I~OH aqueous solution (35
%KOH wlw) and ~80%w/w oil formulation were prepared. The oil formulation
contains 1 - 2 %owlw emulsifying surFactants, ~ 2% w/w dispersant, ~ 3 %ow/w
antioxidant, ~ 1 %wlw aliphatic solvent and 92 - 93 % w/w SAE-50 oil.
The emulsifiers play an important role in the emulsion preparation and
storage stability. The first emulsifier of a blend of two emulsifiers used to
prepare
the examples was a PIBSA:EG:DMEA, polyisobutenyl succinic anhydride:ethylene
glycol :dirnethyl ethanol amine - 2:1:2 (eq). This emulsifier has a high
molecular
weight polyisobutylene chain (~1500MW) and a low HLB. Emulsifier two was a co-
emulsifier. HDSA:DMEA, dodecahexylene succinic anhydride: dimethyl ethanol
amine 1:1 (eq.) It has a low molecular weight and a high HLB. The structures
of
these two emulsifiers are presented below.
Emulsifiers used in the laboratory manufacture of
water/marine lubricating oil emulsion
0 0
N(CH3)a
H
PIB CH3 Hs~ PIB
~~ +~/CH3 +~~ C~sHa~
II H N H3~N H II
O O
OH HO
PIBSA:EG:DMEA HDSA:DMEA
(=2:1:2 (eq)) (=1:1 (eq))
The emulsifiers can be either dosed through an emulsifying concentrate or
could be
directly dissolved in the SAE-50 oil. Other emulsifiers could be used for the
preparation of water/marine lubricating oil emulsions. The water/marine
lubricating
oil emulsion generally also contain a dispersant, like PIBSA:TEPA, a
polyisobutenyl succinic anhydrideaetraethylene pentaamine -3:1 eq end an
antioxidant, like calcium dodecyl phenate sulphide.
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An example of emulsion composition is presented in Table 1.
Table 1: Example of water/marine luhricatinu nil emnlcion
Deionised Sea-water
water
Ingredient based emulsionbased emulsion
%w/w %w/w
KOH 7.00 7.00
Deionised water 13.00 0.00
Synthetic sea water 0.00 13.00
C9-C16 de-aromatized 1.12 1.12
etroleum distillate
I~SA:DMEA 0.31 0.31
PTBSA:EG:DMEA 1.19 1.19
Nominally 1000 MW 1.67 1.67
polyisobutylene grafted
onto
succinic anhydride
(PIBSA)
and further reacted
with a
mixed tetraethylenepentamine
(TEPA)to form an imide
PIBSA:TEPA=3:1 (eq)
A
dis ersant
Calcium dodecyl phenate2.74 2.74
sul hide
SAE-50 oil 72.97 72.97
5
Table 665-98)
2:
Sea-water
Com
osition
(ASTM
D
Sea-water (g/1)
In redients
NaCI 24.54
M Cl2 . 6H20 11.10
Na2S04 4.09
CaCl2 1.16
KCl 0.69
NaHC03 0.20
KBr 0.10
H3BO3 0.03
SrCh . 6H20 0.04
NaF 0.003
The potassium hydroxide solution is prepared by dissolving 35 g KOH
pellets into 75 g of deionised water. This solution is not saturated.
Synthetic sea-
10 water can be used instead of deionised water (prepared as per ASTM D665-98)
but
then the solution becomes saturated at this concentration of KOH.
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The water/marine lubricating oil emulsions can be prepared either i) via a
concentrate, which contains a solvent and two emulsifiers or ii) via a method
which
uses the solvent and emulsifiers dissolved in the oil. Initial samples were
prepared
via a concentrate while later samples were prepared using a solvent and the
emulsifier dissolved in the oil.
i) An emulsifying concentrate was prepared by mixing the two surfactants
with a suitable aliphatic solvent. This concentrate was then mixed until
homogeneous with the oil, which contains a dispersant and an antioxidant. The
concentrate + oil mixture were weighed .into a beaker to which KOH solution
was
added. The mixture was then sheared for 3 - 6 minutes using a high shear
device,
such as a Silverson or a Turrax mixer.
ii) The emulsifying surfactants and aliphatic solvent can be mixed with the
oil, dispersant and anti-oxidant to form an oil formulation. This oil
formulation is
weighed into a beaker to which KOH solution is added. The mixture is then
sheared
for 3 - 6 minutes using a high shear device, such as a Silverson or a Turrax
mixer.
JEmulsi0n Stability
Water/marine lubricating oil emulsions were stored at room temperature and
65°C in order to assess their stability against separation into a water
phase and an oil
phase over time. Stability was assessed after 7 days at room temperature, 7
days at
65°C, 28 days at room temperature and 28 days at 65°C. Emulsion
stability was
semi-quantitatively evaluated by %v/v separation of oil, oily emulsion, band
and
water. The presence of a separated water phase is considered particularly
detrimental. Examples for emulsion stability are shown below. The emulsion
ratings
are reported after 7 and 28 days at room temperature and 65°C.
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Table 3: Emulsion Storage Stability
Emulsifying7 da 7 days
s at
at G5
room C
tem (%v/v)
erature
(%v/v)
surfactants
Emulsion(%w/w Oily Oil Band Water Oily Oil Band Water
in
emulsion)
Prepared
1
50
deionised. 0 0 0 0 1 2 2 0
water
Prepared
with 1
50
synthetic. 1 0 0 0 2 0 18 0
sea-water
28 28
days days
at at
room 65
tem C
erature (%v/v)
(%v/v)
Oil Oil Band Water Oily Oil Band Water
Prepared
with 1.50 0 2 1 0 2 4 2 0
deionised
water
Oily = oil rich phase; oil = clear oil; band = coarse emulsion, results from
the sedimentation of
emulsion particles
A series of tests were performed on water/marine lubricating oil emulsions in
order to assess their behaviour at high temperatures and when in contact with
sulfuric acid.
High Temperature Behaviour
In practice, traditional marine cylinder lubricants experience temperatures of
100-300°C, when in contact with the cylinder walls. The behaviour of
water/marine
lubricating oil emulsion at high temperatures was tested using the test cell
shown in
Figure 4. This test cell consists of a heater finger, which can be heated up
to 350°C
using an Eurotherm. A stainless steel panel fitted on the heater finger. The
panel
and heater finger are placed in a glass cell. The formulation to be tested was
dosed at
the required rate onto the heated panel with the help of a small tube attached
to a
peristaltic pump.
The behaviour of water/marine lubricating oil emulsions was tested at 100,
200 and 300°C and compared to the behaviour at these temperatures of a
standard
marine cylinder lubricating oil (shown in Table 7).
Table 4 presents the results of the high-temperature tests performed on the
water/marine lubricating oil emulsions and the standard oil. The TBN of
emulsions
before the test and after the test (material accumulated in the test cell
sump) were
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determined. The TBN of emulsions after the test were higher than the TBN of
emulsions before the test, which would suggest that the emulsions were
concentrated
(through water loss) and I~OII, existent in emulsions, did not deposit on the
test
panel.
Table 4: High Temperature Test Results
Sample Test temperature~m* (g) ~ TBN
(C) BeforeAfter
DI emulsion100 0.0006 63.0 64.6
SW emulsion100 0 64.6 65.5
Standard 100 0 69.9 69.9
DI emulsion200 0.0097 63.0 70.2
SW emulsion200 0.0253 64.6 69.5
Standard 200 0.0002 69.9 69.9
DI emulsion300 0.0460 63.0 73.2
SW emulsion300 0.0468 64.6 69.8
Standard 300 0.0019 69.9 70.1
Abbreviations: DI = deionised water; SW = synthetic sea-water
*~m = panel mass before hot test - panel mass after hot test
Neutralisation of Sulfuric Acid
The efficiency of water/lubricant oil emulsion in neutralising sulfuric acid
was tested using two methods: a bealeer neutralisation and a high temperature
neutralisation. The latter used the same test-cell as shown in Figure 4.
beaker Neutralization
75.15 g of water/lubricant oil emulsion was weighed in a beaker. 2.25 g of
sulfuric acid (96 % w/w) was then added to the beaker. The mixture was sheared
for
5 minutes using a high shear Turrax mixer set up at 24000 rpm. The TBN of the
water/lubricant oil emulsion was measured before and after the test. This test
was
repeated using the standard marine cylinder lubricant described in Table 7.
Table 5
presents the results of the beaker neutralization test. It can be seen that
the efficiency
of water/lubricant oil emulsion in neutralizing sulfuric acid is comparable to
the
efficiency of the standard oil in neutralizing sulfuric acid.
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Table S: Beaker Neutralization Test Results
TBN Rate of
Sample Before AfterNeutralization*
DI emulsion64.5 33.3 6.3
Standard 70.4 37.6 6.6
Abbreviations: DT = deionised water
Rate of Neutralization = dcKOH / dt - dTBN l dt
High Temperature Neutralization
The test set-up shown in Figure 4 was used for assessing the efficiency of
water/lubricant oil emulsions in neutralizing sulfuric acid at hot
temperatures. The
panel was heated to 100°C. As soon as this temperature was reached, the
flow of
water/lubricant oil emulsion was started through Inlet 1 at 1.67 ml/min. When
the
emulsion covered the panel, the flow of sulfuric acid was started through
Inlet 2 at
0.05 ml/min. The water/lubricant oil emulsion was dosed through a 1 mm bore
size
tube connected to a peristaltic pump, whereas the acid was dosed through a
fine
needle (21Gx35 mm), with the help of a syringe pump. The experiment was
repeated at 200 °C. The standard oil was also assessed at 100 and 200
°C. The
results of these tests are described in Table 6:
Table 6: Hot Temperature Neutralization Tests
Sample Test temperatureTBN _
(C) _Befo_re After
DI emulsion 100 64.9 63.8
Standard oil 100 71.1 69.3
DI emulsion 200 65.2 47.7
Standard oil 200 71.1 58.0
The aim of this test was to mimic a real situation when the lubricating oil
meets the sulfuric acid, formed during the combustion, on the surface of the
hot
metal cylinder walls. The result from Table 6 illustrates that neutralization
of
sulfuric acid by the emulsion or by the standard oil was minimal at
100°C. At 200°C
the emulsion and the standard oil partially neutralized the sulfuric acid.
The tests performed on the water/lubricant oil emulsions showed that KOH
existent in these emulsions would not deposit on the hot cylinder walls and
would
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neutralize the sulfuric acid formed during the combustion. These conclusions
are
based on comparison work performed on a standard marine oil lubricant.
Bolnes Engine test
Bolnes is a turbocharged, 3 cylinder, 2 strolce, low speed marine diesel
5 engine. The Bolnes engine test allows the simultaneous testing of three
different
cylinder oils over a 72 hour period. In the standard test each cylinder
lubricant is
tested in turn in each cylinder of the engine. Several parameters are
rated/measured
in this test. The most important ones are cleanliness ratings, piston ring
wear,
cylinder liner wear and analyses of the cylinder drain samples. The piston
ring
10 grooves, lands and skirt and the scavenging port clogging are rated for
cleanliness.
The weight loss of the rings is recorded as a measure of piston ring wear. The
cylinder drain samples are analyzed for TBN, TAN, ICP/AES, KV100.
Emulsion lubricant was tested in a Bolnes engine test, which only used one
lubricant/cylinder (72 hour test). Cylinder 1 used an emulsion lubricant at
100 %
15 treat rate, cylinder 2 used a standard marine cylinder lubricant and
cylinder 3 used
an emulsion lubricant at 125 % treat rate. The reason for testing an emulsion
lubricant at 125 % treat rate was to allow a fairer comparison between the
standard
lubricant and emulsion lubricant. Emulsion lubricant is composed of 80 % w/w
oil
phase, hence at 100 % treat rate it will deliver less oil than the standard
marine
20 cylinder lubricant. However, at 125 % treat rate, emulsion lubricant
delivers 100 %
oil, allowing for a fairer comparison between emulsion lubricant and the
standard
marine cylinder lubricant. The composition of the tested emulsions and the
standard
marine cylinder lubricant are presented in Table 7.
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Table 7: Lubricants Tested in the Bolnes Engine Test
Ingredients 'Standard' Conventional 'Over-treat'
Emulsion Marine CylinderEmulsion
lubricant Lubricant lubricant '
(%w/w) (%w/w)
KOH 7.00 - 5.G
Deionized water 13.00 - 14.4
Petroleum solvent 1.12 - 0.90
HDSA:DMEA 0.31 - 0.25
PIBSA:EG:DMEA 1.19 - 0.94
PIBSA:TEPA 1.67 - 1.34
calcium dodecyl 2.74 - 2.19
phenate
sul hide
Conventional additive- 20.75 -
acka a
ESSO 600SN 36.49 57.06 37.19
ESSO 150 22.19
36.49 37.19
BRIGHTSTOCK
,~:. .,
~ ~
li.nder Number 1 2 3
C
Treat Rate in the
Bolnes
En ine (%) 100 100 125
TBN delivered at
above
treat rate (maKOH/70 70 70
)
*CAS#64742-48-9 viscosity 2 @ 25 C and boiling point @ 185 C
Analyses of the drain oil samples
Eight drain oil samples (representing the excess oil from the combustion
chambers) wexe collected during the running of the test: at time 0 and after
4, 8, 24,
36, 48, 60, 72 hours. These samples were submitted for TBN, TAN and ICP/AES
analyses. The results of these analyses gave information on the neutralization
of the
sulfuric acid formed during the combustion and the corrosive wear.
Figures 1 and 2 show the changes in TBN and TAN in time in the oil
samples collected from cylinders 1 - 3. The sulphur present in the residual
heavy
fuel, combusted in the Bolnes engine, is oxidised during combustion of the
fuel to
form various acidic products. As the base present in the emulsion lubricants
or
standard marine cylinder lubricant (mcl) reacted with the products of the
sulphur
oxidation, the TBN decreased until it reached equilibrium. This equilibrium
was
reached after ~36 hours in drain oils from the cylinders, which used emulsion
lubricant and after ~GO hours in the drain oils from the cylinders,. which
used
standard mcl. This might indicate a more efficient neutralization of the
sulphur
oxidation products achieved by emulsion lubricant than by the standard mcl.
The
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42
TAN of the drain oil samples increased in time until it reached equilibrium.
The
equilibrium was achieved after ~ 36 hours in the cylinders, which used
emulsion
lubricant and after ~ 60 hours in the cylinder, which used the standard mcl.
All the drain oil samples collected during the running of the Bolnes engine
were analyzed by ICP/AES. The products of the sulphur oxidation formed during
the fuel combustion can 'attack' the metal of the liners or the piston and
cause
corrosive wear, thus iron, copper, nickel, chromium, lead products form and
can be
detected by the analyses of the drain oils. Figure 3 shows the iron content
present in
the drain oil samples collected from cylinders 1-3. It can be observed that
the iron
content of the drain oil samples collected from cylinders 1 and 3 raised for
24 hours
and after that time it reached a plateau. The analyses of the drain oil
samples
collected from the cylinder 2 showed that the iron content increased in time
and did
not reach a plateau during the whole length of the test.
Table 8 summarizes the wear metal content of the drain oil samples at time
zero and at the end of the test. The drain oil sample from cylinder 2
contained more
iron, copper, nickel and chromium than the drain oil samples from cylinders 1
and 3.
These results suggest that emulsion lubricant caused less corrosive wear of
the
components of the cylinder than the standard mcl.
Table 8: ICP/AES Analyses of the Drain Oils - Wear Metal Content
Metal ContentCylinder Cylinder Cylinder
1 2 3
(pprn) 0 hours 72 hours0 hours 72 hours0 hours 72 hours
Fe 1 1694 7 3145 1 1152
Cu 0 93 0 124 0 36
Ni 1 76 1 93 1 64
Cr 0 7 0 10 0 7
Pb 0 3 0 2 0 0
Type of lubricant'Standard' Standard 'Over-treat'
Emulsion mcl Emulsion
lubricant lubricant
emulsion emulsion
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Engine Parts Ratings and Measurements
This section is meant to summarise the ratings and measurements of the
Bolnes engine parts after the test.
Piston Ratings:
Table 9 presents the results of the piston ratings. Overall, the piston
ratings
show an equivalent or in some cases better performance from the emulsion
lubricant
than from the standard mcl.
Table 9: Bolnes Engine Test Results, Piston Ratings
Rating Piston Piston Piston Comments/Observations
1
2 3
Piston Groove Overall, the piston ratings
show a
Carbon (average6.43 6.22 6.46 similar performance from
merits) Marinox as from a standard
Piston Land marine cylinder lubricant.
Carbon (average5.25 5.49 5.56
merits)
Piston Groove 35.73 37.80 35
40
Carbon Fill .
(%)
Piston Ring 9 10.00 10
Stick 88 00
(merits) . .
Less piston ring weight
loss
Piston Ring noticed in the rings
of pistons 1
and 3 than in the rings
Weight Loss 4.540 4.758 3.988 of piston 2
'
'
_
(average grams) over-treat
Marinox better than
'
'
standard
Marinox better than
the standard mcl
More corrosion of the
top-face of
Trace- Light Trace the ring was noticed
in piston 2
Ring Corrosionlight than in pistons 1 and
3. 'Over-
(descriptive) corrosiocoiTOSiconosi treat' Marinox induced
the least
n on on corrosion of the top
face of the
rin .
Slightly more scuffing
Scuffing Trace- was
Trace Trace noticed on piston 1 than
(descriptive) light on
istons 2 and .3.
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Cylinder Ratings:
Table 10 presents the ratings of the liner and air inlet port blockage.
Overall
the emulsion lubricant performed better than the standard mcl. The emulsion
lubricant did not cause quill deposits and air inlet ports deposits and formed
fewer
deposits on the liners than the standard mcl, Corrosion was noticed on the
liner of
the cylinder, which run on the standard mcl and this was not noticed on the
liners of
the cylinders, which run on emulsion lubricant.
Table 10: (~.'vlinder Ratinøc
Ratin C finderC finder C finderComments/Observations
1 2 3
Less average liner diameter
Liner Diameter increase noticed in the
cylinders 1
Increase 0.034 0.062 0.030 and 3 than in the cylinder
2 -
(average - Emulsion lubricant formed
mm) less
de osit than the standard
mcl.
The surface of the liners
1 arid 3
Liner Condition appeared to have less
visible
(visible honing honing lines and a higher
polished
lines/polished5/95 10/90 5/95 surface than the liners
of cylinder
2 - Emulsion lubricant
surface - emulsions
%)
caused slightly more
abrasive
wear than the standard
mcl.
Trace The liner of cylinder
two shows
Areas c~osion trace corrosion, which
of was not
dark ~roughoutAreas observed on the liners
of of cylinders
Liner Condition with smalldarklnbwn1 and 3 - Emulsion lubricant
b
t
(descriptive)rown areas toblack caused less corrosive
o of wear than
black
~kbrown lacquer the standard mcl.
lacquer
to black
lac uer
The standard mcl caused
trace
Air Inlet blockage of the air inlet
Port port - this
Blockage Nil Trace Nil was not observed in cylinders
1
(descriptive) and 3, which used Emulsion
lubricant emulsion.
Emulsion lubricant caused
only
Fire land Mainly Mainly Trace traces of fire land deposits,
deposits while
(descriptive)removed black flaking the standard mcl caused
black
de osits
Quill deposits Trace- Emulsion lubricant did.
N not cause
l
(descri tive)r li ht Nil uill de osits
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Summary of the Bolnes Test Ratings and Analyses
In summary the emulsion lubricant resulted in improved properties over the
standard marine cylinder lubricant in tests for piston ring groove carbon,
piston ring
land carbon, piston ring weight loss, corrosive wear, liner diameter increase,
fire
5 land and quill deposits, and air inlet blockage. The emulsion lubricant
resulted in
comparable properties for the ring stick and adhesive wear. Depending on the
need
for acid neutralization, the treat rate with the emulsion lubricant of this
disclosure
may be less than the treat rate with standard marine cylinder lubricants.
Further the
emulsion lubricants are compatible with standard marine cylinder lubricants
and
10 could be blended to obtain optimal properties and to reduce costs.
Based on reductions in NOx seen with fuels that incorporate water, it is
anticipated that the water in the marine emulsion lubricant will lower the
combustion temperature in the cylinders slightly and thereby reduce the NOx
emissions of the engine. The amount of NOx reduction will be determined by the
15 total amount of water injected with the emulsion lubricant.
While the invention has been explained in relation to its preferred
embodiments, it is to be understood that various modifications thereof will
become
apparent to those skilled in the art upon reading the specification.
Therefore, it is to
be understood that the invention disclosed herein is intended to cover such
20 modifications as fall within the scope of the appended claims.
Each of the documents referred to above is incorporated herein by reference.
Except in the Examples, or where otherwise explicitly indicated, all numerical
quantities in this description specifying amounts of materials, reaction
conditions,
molecular weights, number of carbon atoms, and the like, are to be understood
as
25 modified by the word "about." Unless otherwise indicated, each chemical or
composition referred to herein should be interpreted as being a commercial
grade
material which may contain the isomers, by-products, derivatives, and other
such
materials which are normally understood to be present in the commercial grade.
However, the amount of each chemical component is presented exclusive of any
30 solvent or diluent oil, which may be customarily present in the commercial
material,
unless otherwise indicated. It is to be understood that the upper and lower
amount,
range, and ratio limits set forth herein may be independently combined. While
ranges are given for most of the elements of the invention independent of the
ranges
for other elements, it is anticipated that in more preferred embodiments of
the
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46
invention, the elements of the invention are to be combined with the various
(assorted) desired or preferred ranges for each element of the invention in
various
combinations. As used herein, the expression "consisting essentially of"
permits the
inclusion of substances that do not materially affect the basic and novel
characteris-
tics of the composition under consideration.
