Note: Descriptions are shown in the official language in which they were submitted.
113841~
LF-1680-Ca
This invention relates to new magnesium-containing
compositions of matter and methods for their preparation.
In a general sense, the invention comprises thixotropic non-
carbonated magnesium-containing complexes which are prepared
by heating, at a temperature above about 30C., a mixture
comprising:
(A) At least one of magnesium hydroxide, mag-
nesium oxide, hydrated magnesium oxide and a magnesium
alkoxide;
(B) At least one oleophilic organic reagent com-
prising a carboxylic acid, a mixture of a major amount
thereof with a minor amount of a sulfonic acid or
pentavalent phosphorus acid, or an ester or alkali
metal or alkaline earth metal salt of either of these;
`~
~F
113841~'
--2--
(C) Water, if necessary to convert a substantial
proportion of component A to magnesium hydroxide or
hydrated magnesium oxide; and
(D) At least one organic solubilizing agent for
component B;
the ratio of equivalents of magnesium to the acid
portion of component B being at least akout 5:1; and the
amount of water present, if any, being sufficient to hydrate
a substantial proportion of component A calculated as mag-
10 nesium oxide.
Several methods are known for the preparation of
basic magnesium compounds for use in lubricants, greases and
the like. For example, U.S. Patent 3,865,737 describes the
formation of a highly basic magnesium-containing liquid dis-
15 persion by mixing an oil-soluble dispersing agent, magnesium
oxide, a volatile aliphatic hydrocarbon solvent, alcohol,
water and ammonia or an ammonium compound, treating the mix-
ture with carbon dioxide, adding a non-volatile diluent oil
and removing volatiles. Similarly, U.S. Patent 3,629,109
20 describes the carbonation of a mixture of an oil-soluble
organic acid or salt thereof, magnesium oxide, a lower ali-
phatic alcohol, water and an organic liquid diluent. The
products obtained by these methods may be characterized, for
the most part, as basic oleophilic magnesium carbonates
25 since an essential step in their preparation is reaction
with carbon dioxide.
In accordance with the present invention, it has
been discovered that highly basic, thixotropic magnesium
complexes may be prepared without reaction with carbon
30 dioxide or similar acidic gases. The products obtained in
accordance with the present invention, which may be charac-
terized:as complexes of magnesium oxide or hydroxide and a
magnesium salt of the acid comprising component B, and which
are hereinafter sometimes referred to merely as "magnesium
35 complexes", have a wide variety of uses, including additives
113~34~'~
--3--
for lubricants and fuel oils and corrosion-resistant coat-
ings or constituents thereof.
A principal object of the present invention,
therefore, is to provide new oleophilic magnesium-containing
compositions and a method for their preparation.
A further object is to provide a method for pro-
ducing magnesium complexes which does not necessitate reac-
tion with carbon dioxide or a similar acidic gas.
A further object is to provide basic thixotropic
10 magnesium compositions which may be obtained either in
liquid or solid form.
Still another object is to provide thixotropic
magnesium-containing compositions useful as greases, as
detergent additives for lubricants or as corrosion inhi-
15 bitors, vanadium scavengers and smoke suppressants forfuels, and in the formulation of corrosion-resistant coat-
ings for metals.
Other objects will in part be obvious and will in
part appear hereinafter.
20 Component A
Component A used in the method of this invention
is magnesium hydroxide, magnesium oxide, hydrated magnesium
oxide, a maynesium alkoxide, or a mixture of these. Magne-
sium hydroxide and magnesium oxide are, of course, repre-
25 sented by the formulas Mg(OH) 2 and MgO, respectively.Magnesium oxide exists in an inactive "dead burned" and a
hydratable "reactive" form and the latter is the one which
is useful in this invention although mixtures~of the "reac-
tive" form with minor amounts of the "dead burned" form may
30 also be used. "Hydrated magnesium oxide", for the purpose
of this invention, is magnesium oxide which is associated
with water in an amount less than that required for con-
version to magnesium hydroxide; that is, the amount of water
is less than one mole per mole of magnesium oxide. As so
35 defined, "hydrated magnesium oxide" may actually be a mix-
~138~12
ture of various proportions of magnesium oxide and magnesium
hydroxide and its exact chemical nature is not critical to
this invention. Typically, the amount of water present in
"hydrated magnesium oxide" is at least about 0.7 mole per
mole of the oxide.
The magnesium alkoxides, especially the lower
alkoxides ti.e., those in which the alkyl groups contain 7
carbon atoms or less), are equivalent to magnesium oxide and
hydroxide for the purpose of this invention; they are
hydrolyzed by water to magnesium hydroxide under the con-
ditions described hereinafter.
The equivalent weight of component A is half its
molecular weight, since magnesium is a divalent element.
Component B
Component B is at least one oleophilic reagent
comprising a carboxylic acid or a mixture thereof with a
sulfonic acid, or salts or esters thereof. These acids
include many of those known to be susceptible to overbasing
and especially many of those disclosed in a number of U.S.
patents such as 2,616,904; 2,695,910; 3,312,618; 3,746,643;
3,764,533; and the aforementioned 3,629,109. Those patents
disclose suitable acidic oleophilic reagents.
The carboxylic acids suitable for use as component
B include aliphatic, cycloaliphatic and aromatic mono- and
polybasic carboxylic acids free from acetylenic unsatur-
ation, including naphthenic acids, alkyl- or alkenyl-sub-
stituted cyclopentanoic acids, alkyl- or alkenyl-substituted
cyclohexanoic acids, and alkyl- or alkenyl-substituted
aromatic carboxylic acids. The aliphatic acids generally
contain from about 8 to about 50, and preferably from about
12 to about 25, carbon atoms. The cycloaliphatic and ali-
phatic carboxylic acids are preferred and they can be
saturated or unsaturated. Specific examples include 2-
ethylhexanoic acid, linolenic acid, propylene tetramer-
substituted maleic acid, behenic acid, isostearic acid,
pelargonic acid, capric acid, palmitoleic acid, linoleic
1~3~41Z
--5--
acid, lauric acid, oleic acid, ricinoleic acid, undecylic
acid, dioctylcyclopentanecarboxylic acid, myristic acid,
dilauryldecahydronaphthalenecarboxylic acid, stearyl-octa-
hydroindenecarboxylic acid, palmitic acid, alkyl- and
alkenylsuccinic acids, acids formed by oxidation of petro-
latum or of hydrocarbon waxes, and commercially availablemixtures of two or more carboxylic acids such as tall oil
acids, rosin acids, and the like.
The above-described carboxylic acids may be used
in admixture with a minor amount of a sulfonic or penta-
valent phosphorus acid; that is, component B may comprise a
mixture containing more than 50~ by weight of carboxylic
10 acids and less than 50~ of sulfonic or pentavalent phos-
phorus acids. Suitable sulfonic acids include those repre-
sented by the formulas Rl(SO3H)r and (R2)XT(SO3H)y. In
these formulas, Rl is an aliphatic or aliphatic-substituted
cycloaliphatic hydrocarbon or essentially hydrocarbon
radical free from acetylenic unsaturation and containing up
to about 60 carbon atoms. When Rl is aliphatic, it usually
15 contains at least about 15 carkon atoms; when it is an
aliphatic-substituted cycloaliphatic radical, the aliphatic
substituents usually contain a total of at least about 12
carbon atoms. Examples of Rl are alkyl, alkenyl and alkoxy-
alkyl radicals, and aliphatic-substituted cycloaliphatic
radicals wherein the aliphatic substituents are alkyl,
20 alkenyl, alkoxy, alkoxyalkyl, carkoxyalkyl and the like.
Generally, the cycloaliphatic nucleus is derived from a
cycloalkane or a cycloalkene such as cyclopentane, cyclo-
hexane, cyclohexene or cyclopentene. Specific examples of
Rl are cetylcyclohexyl, laurylcyclohexyl, cetyloxyethyl,
octadecenyl, and radicals derived from petroleum, saturated
and unsaturated paraffin wax, and olefin polymers including
25 polymerized monoolefins and diolefins containing about 2-E
carbon atoms per olefinic monomer unit. Rl can also contain
113t34~'~
--6--
other substituents such as phenyl, cycloalkyl, hydroxy,
mercapto, halo, nitro, amino, nitroso, lower alkoxy, lower
alkylmercapto, carboxy, carbalkoxy, oxo or thio, or inter-
rupting groups such as -N~I-, -O- or -S-, as long as the
essentially hydrocarbon character thereof is not destroyed.
R2 is generally a hydrocarbon or essentially
hydrocarbon radical free from acetylenic unsaturation and
containing from akout 4 to about 60 aliphatic carbon atoms,
preferably an aliphatic hydrocarbon radical such as alkyl or
10 alkenyl. It may also, however, contain substituents or
interrupting groups such as those enumerated above provided
the essentially hydrocarbon character thereof is retained.
In general, the non-carbon atoms present in Rl or R2 do not
account for more than 10% of the total weight thereof.
The radical T is a cyclic nucleus which may be
derived from an aromatic hydrocarbon such as benzene,
naphthalene, anthracene or biphenyl, or from a heterocyclic
compound such aspyridine, indole or isoindole. Ordinarily,
T is an aromatic hydrocarbon nucleus, especially a benzene
20 or naphthalene nucleus.
The subscript x is at least 1 and is generally 1-
3. The subscripts r and y have an average value of about 1-
4 per molecule and are generally also 1.
Illustrative sulfonic acids useful as part of
25 component B are mahogany sulfonic acids, petrolatum sulfonic
acids, mono- and polywax-substituted naphthalene sulfonic
acids, cetylchlorobenzene sulfonic acids, cetylphenol sul-
fonic acids, cetylphenol disulfide sulfonic acids, cetoxy-
capryl benzene sulfonic acids, dicetyl thianthrene sulfonic
30 acids, dilauryl ~-naphthol sulfonic acids, dicapryl nitro-
naphthalene sulfonic acids, paraffin wax sulfonic acids,
unsaturâted paraffin wax sulfonic acids, hydroxy-substituted
paraffin wax sulfonic acids, tetraisobutylene sulfonic
acids, tetra-amylene sulfonic acids, chloro-substituted
35 paraffin wax sulfonic acids, nitroso-substituted paraffin
113~4~Z
--7--
wa~ sulfonic acids, petroleum naphthene sulfonic acids,
cetylcyclopentyl sulfonic acids, lauryl cyclohexyl sulfonic
acids, mono- and polywa~-substituted cyclohexyl sulfonic
acids, postdodecylbenzene sulfonic acids, "dimer alkylate"
sulfonic acids, and the like. These sulfonic acids are
well-known in the art and require no further discussion
herein.
The pentavalent phosphorus acids useful as part of
component B may be represented by the formula
X4
R3(Xl) \ ll
P-X3H
R4(X 2 )/
wherein each of R3 and R4 is hydrogen or a hydrocarbon or
essentially hydrocarbon radical preferably having from about
4 to about 25 carbon atoms, at least one of R3 and R4 being
hydrocarbon or essentially hydrocarbon; each of Xl, X2, X3
15 and X4 is oxygen or sulfur; and each of a and b is O or 1.
Thus, it will be appreciated that the phosphorus acid may be
an organophosphoric, phosphonic or phosphinic acid, or a
thio analog of any of these.
Usually, the phosphorus acids are those of the
R30 \ 00 formula / -OH wherein R3 is a phenyl radical or
R40
(preferably) an alkyl radical having up to 18 carbon atoms,
and R4 is hydrogen or a similar phenyl or alkyl radical.
Mixtures of such phosphorus acids are often preferred
because of their ease of preparation.
Also useful as component B are the alkali metal
and alkaline earth metal salts (e.g., sodium, potassium,
magnesi~m, calcium, strontium or barium salts, with mag-
nesium salts being preferred) and esters of the acids pre-
viously described. The suitable esters include those with
30 monohydric alcohols free from acetylenic unsaturation and
having from about 1 to about 25 carbon atoms, including
11384~Z
--8--
monohydric alcohols such as methanol, ethanol, the butanols,
the hexanols, allyl alcohol, crotyl alcohol, stearyl alcohol
and oleyl alcohol, and polyhydric alcohols such as ethylene
glycol, diethylene glycol, propylene glycol, glycerol,
sorbitol, sorbitan and similar carbohydrates and derivatives
of carbohydrates.
It will be appreciated from the above description
of component B that it comprises an organic acid or a com-
pound hydrolyzable thereto. The ratio of equivalents of
10 magnesium to equivalents of acid is important in the context
of the invention, and so the equivalent weight of the acid
portion of component B must be defined.
Obviously, to the extent that co~ponent B is a
free acid its equivalent weight is its molecular weight
15 divided ky the number of acidic groups present per molecule.
To the extent component B is an ester or salt of a car-
boxylic or sulfonic acid, it is considered to be convertible
to the free acid during the reaction with component ~ and
water and its equivalent weight is similarly calculated. To
20 the extent that component B is a phosphorus acid or a salt
or ester thereof, its equivalent weight is its molecular
weight divided by the sum of the acidic hydroxy groups
bonded to phosphorus (or salts thereof) and the number of
ester groups hydrolyzable to such hydroxy groups (or salts
25 thereof) under the reaction conditions of the invention. If
any ester groups remain unhydrolyzed, the ester is consi-
dered inert to that extent for the purpose of calculating
equivalent weight.
The preferred compounds for use as component B are
30 the above-described carboxylic acids having an equivalent
weight b~etween about 200 and about 500 and mixtures thereof
with sulfonic acids of similar molecular weight, especially
alkylaromatic sulfonic acids and more particularly alkyl-
benzenesulfonic acids.
One of the characteristics of component B is that
it is oleophilic. This means that it is soluble or at least
1~3841Z
_9_
stably dispersible (as defined hereinafter) in oil or
similar non-polar organic liquids such as hexane, naphtha,
Stoddard solvent, benzene, toluene and the like. While
component B need not be oil-soluble, the oil-soluble acids
are preferred for the purposes of this invention. These
oil-soluble compounds constitute a known subgenus of the
previously described compounds useful as component B.
Component C
Component C is water, which may be used in the
10 liquid or vapor phase ard is under certain conditions op-
tional (as described hereinafter). For the purpose of the
present invention, the equivalent weight of water is con-
sidered to be 9 (half its molecular weight).
Component D
-
Component D is at least one organic solubilizing
agent for component B. It may bé solid or liquid at room
temperature, although liquids are often preferred. It need
not be a solvent for component B, in the sense that com-
ponent B is entirely soluble therein when in the liquid
20 state, but should be at least a partial solvent in the sense
that relatively small proportions of component B, at least,
when blended with component D in the liquid state will form
a homogeneous mixture.
Materials useful as component D include substan-
25 tially inert, normally liquid organic diluents. The term
"substantially inert" as used herein is intended to mean
that the diluent is inert to chemical or physical change
under the conditions in which it is used so as not to
materially interfere in an adverse manner with the pre-
30 paration, storage, blending and/or functioning of the mag-
nesium complex in the context of its intended use. For
example:; small amounts of a diluent can undergo minimal
reaction or degradation without preventing the making and
using of the invention as described herein. In other words,
35 such reaction or degradation, while technically discernible,
would not be sufficient to deter the practical worker of
~13~41Z
--10--
ordinary skill in the art from making and using the inven-
tion for its intended purposes. "Substantially inert" as
used herein is thus readily understood and appreciated ky
those of ordinary skill in the art.
Among the preferred normally liquid diluents are
non-polar compounds or mixtures of compounds such as naph-
tha, hexane, kerosene, mineral oil, Stoddard solvent,
benzene, toluene, xylene, low molecular weight polybutenes,
and alkylbenzenes of the type present as unsulfonated
10 residue in alkylbenzenesulfonic acids. Also suitable are
somewhat more polar liquids such as l-butanol, 2-butanol,
ethylene glycol, propylene glycol, ethylene glycol mono-
methyl ether, ethylene glycol monobutyl ether, ethylene
glycol dimethyl ether, diethylene glycol and its ethers,
15 wax-derived alcohol mixtures, methyl ethyl ketone, chloro-
benzene, pyridine, indole, furan and tetrahydrofuran.
Also useful are substantially inert materials
which are solid at ambient temperature, and which may be
chemically similar to the above-described liquids. These
20 include the following:
1. Waxes, such as:
Crystalline (including microcrystalline)
wax
Paraffin wax
Petrolatum wax
Beeswax
Bohemia wax
Hydrogenated castor oil
Lanolin
Shellac wax
Spermaceti
Carnauba wax
Candelilla wax
Chlorinated naphthalene
~31341Z
~Taxy alcohol mixtures (e.g. ~ C2 0-4 0
aliphatic alcohols)
Other waxy materials of the type dis-
closed in Kirk-Othmer, T~ncyclopedia
of Chemical Technology, Second
Edition, vol. 22, pp. 156-173
(which is incorporated by refer-
ence herein for such aisclosure)
2. Hydrocarkon and similar resins, such as:
Olefin polymer resins and ~-axes (e.g.,
polyethylene, polypropylene)
Terpene resins
Coumarone-indene resins
Phenolic and,alkylated phenolic resins
Furan resins '~
3. Matural resins, such as:
Copal
~anila chips
Gum damar
Accroides gum
Rosin
Hydroabietyl alcohol resin
4. Addition polymer resins, such as:
Styrene-butadiene
Hydrogenated styrene-butadiene
1138~12
-12-
Polystyrene and poly(~-methylstyrene)
Olefin-vinyl acetate copolymers
Polyvinyl acetate
Polyvinyl chloride
Vinyl acetate-vinyl chloride copolymers
Acrylic resins
Solid polybutenes
5. Polyester resins
6. Solid plasticizers, such as:
Triethylene glycol dibenzoate
Neopentyl glycol dibenzoate
Glyceryl tribenzoate
It is also within the scope of the invention to
use mixtures of any of the materials described above. Such
15 mixtures may be of materials all of which are liquid at
normal ambient temperatures ~e.g., about 20-30C.), such as
mineral oil-toluene, Stoddard solvent-toluene, mineral oil-
alkylbenzene, Stoddard solvent-alkylbenzene; of materials
all of which are solid at normal ambient temperatures, such
20 as paraffin wax-polyethylene wax, paraffin wax-polyethylene
wax-C2 0-4 0 alcohol wax; or of materials which are both
liquid and solid at normal ambient temperatures, such as
mixtures of the above-mentioned normally liquid diluents and
a resin or hydrocarbon wax (e.g., paraffin wax-toluene,
25 polypropylene-toluene, polypropylene-mineral oil).
Component Proportions
The relative proportions of components A, B, C and
D are an important feature o' this invention since the
physica~ state in which the magnesium complex is obtained
30 depends to a great extent on the proportions of the com-
ponents used for their preparation.
As previously noted, the ratio of equivalents of
magnesium to the acid portion of component B is at least
11384~
-13-
about 5:1. This ratio is hereinafter sometimes referred to
as the "magnesium ratio". tIt will be appreciated that the
magnesium ratio is such as to produce a basic magnesium
complex.) If component B is a free carboxylic acid or an
ester or salt thereof with a metal other than magnesium, the
ratio of component A to component B will be identical to the
magnesium ratio. If component B is a magnesium salt, the
ratio of component A to component B will be somewhat less
than the magnesium ratio since part of the magnesium is
10 provided ky component s.
It has been found that magnesium complexes with
relatively low maynesium ratios (e.g., from about 5:1 to
about 21:1 and particularly from about 5:1 to about 10:1)
are particularly useful as lubricant additives. Complexes
15 with a magnesium ratio above about 60:1 and preferably up to
about 150:1 find utility principally as additives for fuel
oils. As protective coatings for metals, it is preferred to
employ complexes in which component D is entirely or pre-
dominantly liquid and the magnesium ratio is between about
20 25:1 and about 60:1, or solid te-g., "hot melt") complexes
in which component D is entirely or predominantly solid at
ambient temperature and which typically have a magnesium
ratio from about 5:1 to about 50:1.
The ratio of moles of water (component C) to
25 grams-atoms of magnesium in component A tsaid ratio herein-
after sometimes designated the "water ratio") is also
critical. ~Jhen component A is substantially all magnesium
hydroxide or hydrated magnesium oxide, the prèsence of water
is frequently not required. If water is not present,
30 however, complex preparation usually requires extremely
efficie~t high-speed mixing te-g-, by mixers such as that
sold under the trade ~K~"Dispersator" by Premier Mill
Corporation) so as to produce a uniform product. When a
substantial portion of component A is magnesium oxide or a
35 magnesium alkoxide, the presence of water as component C is
required.
~J~3~1Z
Most often, the use of water is advantageous
regardless of the identity of component A. When it is
present, the amount of water should be at least sufficient
to hydrate a substantial proportion of component A, cal-
culated as magnesium oxide. The proportion of additionalwater over and above that amount will depend on the nature
of the product desired and the intended use thereof. If
component A is anhydrous magnesium oxide the water ratio
should generally be at least about 0.7:1 so as to produce a
10 substantial proportion of the hydrated magnesium oxide
referred to hereinabove.
A water ratio up to about 3.0:1, and especially
from about 0.7:1 to about 3.0:1, is usually adequate to
produce a composition of this invention. If larger amounts
15 Of water than this are used, it is frequently possible to
remove excess water, at least some of which separates from
the magnesium complex as a separate layer and the remainder
of which can be removed by azeotropic distillation or the
like. More water may be desirable for the preparation of
20 the complex in certain instances; for example, magnesium
oxide frequently contains traces of sodium compounds whose
presence may be undesirable in the complex, and if so, such
compounds may be removed by using up to about 8 moles of
water per mole of component A and removing the excess, which
25 has dissolved therein the sodium compounds. When the excess
water has been removed, the molar ratio of remaining water
to component A is usually below about 3:1 as noted above.
As among various magnesium complexes-with water
ratios between about 0.7:1 and about 3.0:1, those having a
30 water ratio below about 1:1 are often particularly useful as
lubricant additives or fuel oil additives, while those
having a somewhat higher water ratio (e.g., between about
1:1 and 3:1) may be particularly useful in the preparation
of corrosion-resistant coating compositions.
The ratio of component D to component A is not
critical and may be varied so as to provide magnesium com-
1138~1Z
-15-
plexes suitable for the particular use for which they are
intended. For example, a complex suitable as a lubricant
additive may frequently be obtained by employing as com-
ponent D solely the unsulfonated alkylbenzene present as an
impurity in the sulfonic acid used as component B. In that
event, the weight ratio of component D to component A will
usually be below about 1:1 and frequently as low as 0.5-
0.7:1. In general, when a lubricant additive product is
desired it is inaclvisable to use volatile materials as
10 component D.
When the magnesium complex is to be used as a fuel
oil additive, higher amounts of component D are frequently
preferred and these may include relatively volatile mat-
erials such as toluene or xylene, less volatile materials
15 such as mineral oil or mineral seal oil, and mixtures of
volatile and less volatile materials. The proportions of
volatile and non-volatile solubilizing agents in such
mixtures are subject to wide variation, but in any event it
is usually found that the total weight ratio of component D
20 to component A should be from about 1.2:1 to about 1.8:1.
When a product useful in a protective metal coat-
ing is desired, still higher ratios (e.g., from about 2:1 to
about 3:1) are often employed with one of the solubilizing
agents being a substantially volatile aliphatic hydrocarbon
25 such as naphtha or StOddard solvent, and the other being a
somewhat less volatile material such as mineral oil. Ano-
ther useful type of complex for metal coating is the solid
(e.g., "hot melt") type briefly referred to hereinabove, in
which component D comprises mostly or entirely materials
30 which are solid at ambient temperature, in which case the
ratio of D to ~ may be between about 0.5:1 and about 6:1.
Prepara~ion of the Magnesium Complex
The magnesium complexes of this invention are pre-
pared by merely blending the components described herein-
35 above and heating the resulting blend at a temperature above
113~41;~
-16-
about 30C. It is important that water (if present as
component C) remain in the blend during substantially the
entire period of preparation of the magnesium complex, and
the maximum temperature thereof should be adjusted accord-
ingly. ~lowever, said water may be present in the liquid orvapor state, i.e., as liquid water or as steam, though it
will be apparent to those skilled in the art that the
preparation of complexes involving a relatively large amount
of water will be difficult if not impossible, at least at
10 atmospheric pressure, if the water is present as steam.
Therefore, it is generally found that temperatures between
about 30 and about 125C. are most conveniently employed at
atmospheric pressure, and the preparation should be carried
out under superatmospheric pressure if the use of higher
15 temperatures is likely. Most often, a maximum temperature
of about 100C. is convenient when component D is entirely
or predominantly liquid and the preferred temperature range
is then between about 40 and about 90C. Naturally, the
temperature may be somewhat higher (e.g., between about 95
20 and about 150C.) when component D is entirely or predomi-
nantly a solid at ambient temperature.
The order of addition of the various components is
not critical. It is often convenient to first combine
components A, B and D and subsequently to add component C
25 (water) either all at once or incrementally. It is also
often found convenient to prepare an initial mixture con-
taining only a relatively small portion of component A
(e.g., from about 5% to about 10% of the total`amount
thereof) and to add the remainder at a later stage, typi-
30 cally during or after the addition of water. Finally, it iswithin the scope of the invention to prepare the magnesium
complex using only a portion of the amount of component D
intended, and to add the remainder after the complex has
been prepared. The amount subsequently added is generally
35 less than about 50% and preferably less than about 40% by
1138~
weight of the total amount to be used. This subsequent
addition of part of component D is most often useful when
component D is partly or entirely solid (for example, when
it comprises waxes and/or resins) and/or ~hen it imparts
additional desirable properties such as modifying fluidity
under the conditions of use.
The magnesium complexes of this invention are
thixotropic; that is, they decrease in viscosity when
agitated and return to approximately their original vis-
10 cosity after agitation ceases. When component D is pre-
dominantly liquid, the complexes are typically viscous
liquids or heterogeneous dispersions in the form of greases
or gels. When component D is predominantly solid, the
magnesium complex may be a solid,"hot melt" type material.
The solid materials are useful for many purposes,
such as for the formation of corrosion-resistant coatings as
described hereinafter. For some other applications, such as
those involving lubricants and fuels, the complex is pre-
ferably obtained in the form of a relatively non-viscous,
20 easily flowable liquid. Such liquids may be obtained by
methods well known to those of skill in the art, such as by
maximizing the amount of liquid diluent present as component
D or by decreasing the relative amount of component A or
component C in the reaction mixture. Alternatively, a
30 viscous or solid complex can be further diluted with a
substantially inert organic liquid diluent of the type
described hereinabove to produce a homogeneous--solution.
One of the unique and desirable characteristics of the
thixotropic compositions of this invention is their capa-
.
11~8~12
-18-
bility of existing either as heterogeneous compositions or
homogeneous, relatively dilute solutions or dispersions.
A method which is sometimes advantageous for
incorporating relatively large amounts of magnesium while
making possible the formation of a homogeneous solution or
dispersion in mineral oil or the like is to prepare the
complex in the presence of ammonium hydroxide, which may be
prepared from ammonia and the water present as component C.
The amount of ammonium hydroxide required is small, gen-
10 erally less than a~out 10~ by weight based on the waterpresent. Insoluble materials can then be removed by dilu-
ting with a non-polar volatile organic liquid such as
hexane or naphtha, centrifuging, and stripping the volatile
liquid, or by equivalent means.
Another method for clarifying the magnesium
complex for use in mineral oil, which may be employed in
addition to or in place of preparation in the presence of
ammonium hydroxide, is to add water or an acidic or kasic
reagent after preparation of the complex. The acidic or
20 basic reagent may be organic or inorganic; suitable ones
include sodium hydroxide, potassium hydroxide, ammonium
hydroxide, triethanolamine, tartaric acid and citric acid.
The amount of water or acidic or basic reagent is generally
less than about 10% by weight of the magnesium complex
~5 system.
The stability of the magnesium complexes of this
invention is often improved if a minor effective amount of
an oxidation inhibitor is incorporated therein. Suitable
oxidation inhibitors include the hindered phenol type,
30 illustrated by 2,6-di-t-butylphenol and its derivatives; and
the arylamine type, illustrated by phenyl-~-naphthylamine.
The amo~r;t of antioxidant required is usually between about
0.1~ and akout 2% and preferahly between about 0.2~ and 1%
by weight. Oxidation inhibitors are particularly useful in
35 the corrosion-resistant coating compositions of this inven-
tion since they inhibit viscosity decreases thereof.
113B41Z
-- 19 --
The preparation of the magnesium complexes of this
invention is illustrated by the following examples. All
parts are by weight.
Example 1
A mixture of 754 parts of water, 23 parts of
magnesium oxide, 210 parts of mineral oil and 247 parts of
Stoddard solvent is heated to about 40C. and 331 parts of a
carboxylic acid having an equivalent weight of about 350 and
obtained by oxidation of petrolatum, which acid has been
preheated to about 50-60C., is added as the temperature of
the mixture is maintained at 40-45C. An additional 350
parts of magnesium oxide is added, with stirring, and the
temperature of the mixture is increased to 75C. An opaque
dispersion is obtained which is screened to afford the
desired magnesium oxide-carboxylate complex.
Example 2
A product similar to that of Example 1 is pre-
pared, substituting about 300 parts of sorbitan trioleate
for the oxidized petrolatum.
Example 3
A mixture of 16 parts of an alkylbenzenesulfonic
acid having an equivalent weight of about 430 and containing
about 22% unsulfonated alkylbenzene, 305 parts of mineral
oil, 180 parts of magnesium oxide and 96 parts of the mixture
sold under the trade mark "Hydrex 440", a mixture of hydrogenated
fatty acids obtainable from Union Camp Corporation, is heated
to 95C. and blown with steam for two hours. The temperature
is increased to 145-150C., an additional 28 parts of mineral
oil is added and the mixture is blown with air as the temperature
is heated to 170C. over 15 minutes. The mixture is then cooled
to room temperature and an additional 44 parts of mineral oil
is added to yield the desired magnesium oxide-carboxylate-
sulfonate complex having the consistency of a grease.
~13~9~1;2
-20-
Lubricants and Fuels
When in the form of flowable liquids as previously
described, the magnesium complexes of this invention are
stably dispersible in the normally liquid media (e.g., oil,
fuel, etc.) in which they are intended to function. Thus,
for example, compositions intended for use in oils are
stably dispersible in an oil in which they are to be used.
The term "stably dispersible" as used in the specification
and appended claims is intended to mean the magnesium com-
10 plex or other material is capable of being dispersed in agiven medium to an extent which allows it to function in its
intended manner. Thus, for example, when a magnesium com-
plex is used in an oil, it is sufficient that it be capakle
of being suspended in the oil in an amount sufficient to
15 enable the oil to possess one or more of the desired pro-
perties imparted to it by the suspended complex. Such
suspension can be achieved in various conventional ways.
For example, in constantly circulating oil or oil in splash
lubricating systems, physical agitation can keep the complex
20 suspended in oil. Likewise, conventional dispersants (such
as the acylated nitrogen dispersants disclosed in U.S.
Patent 3,219,666) often found in lubricating oils and fuels
promote the stable dispersion or suspension of the magnesium
complex. In any event, the complex will be "stably dis-
25 persible" in the normally liquid media in which it will be
used in at least the minimum concentrations set forth
elsewhere herein. Thus, the terminology "stably disper-
sible" is used in a conventional manner and will be un-
derstood by those of ordinary skill in the art.
As previously indicated, the magnesium complexes
of this invention may be homogeneously incorporated into
lukrica~ts, in which they function primarily as ash-pro-
ducing detergents. They can be employed in a variety of
lubricants based on diverse oils of lubricating viscosity,
3S including natural and synthetic lubricating oils and mix-
~13Ei 4~2
tures thereof. These lubricants include crankcase lubri-
cating oils for spark-ignited and compression-ignited
internal combustion engines, including automobile and truck
engines, two-cycle engines, aviation piston engines, marine
and railroad diesel engines, and the like. They can also be
used in gas engines, stationary power engines and turbines
and the like. Automatic transmission fluids, transaxle
lubricants, gear lubricants, metal-working lubricants,
hydraulic fluids and other lubricating oil and grease
10 compositions can also benefit from the incorporation therein
of the compositions of the present invention.
Natural oils include animal oils and vegetable
oils (e.g , castor oil, lard oil) as well as liquid petro-
leum oils and solvent-treated or acid-treated mineral
15 lubricating oils of the paraffinic, naphthenic or mixed
paraffinic-naphthenic types. Oils of lubricating viscosity
derived from coal or shale are also useful base oils.
Synthetic lubricating oils include hydrocarbon oils and
halo-substituted hydrocarbon oils such as polymerized and
20 interpolymerized olefins [e.g., polybutylenes, polypro-
pylenes, propylene-isobutylene copolymers, chlorinated
polybutylenes, poly(l-hexenes), poly(l-octenes), poly(l-
decenes), etc. and mixtures thereof]; alkylbenzenes (e.g.,
dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di(2-
25 ethylhexyl)benzenes, etc.); polyphenyls (e.g., biphenyls,terphenyls, alkylated polyphenyls, etc.), alkylated diphenyl
ethers and alkylated diphenyl sulfides and the derivatives,
analogs and homologs thereof and the like. ~
Alkylene oxide polymers and interpolymers and
30 derivatives thereof where the terminal hydroxyl groups have ~ -
been modified by esterification, etherification, etc. con-
stituteranother class of known synthetic lubricating oils.
These are exemplified by the oils prepared through poly-
merization of ethylene oxide or propylene oxide, the alkyl
35 and aryl ethers of these polyoxyalkylene polymers (e.g.,
~3841Z
-22-
methyl-polyisopropylene glycol ether having an average
molecular weight of 1000, diphenyl ether of polyethylene
glycol having a ~olecular weight of 500-1000, diethyl ether
of polypropylene glycol having a molecular weight of 1000-
1500, etc.) or mono- and polycarboxylic esters thereof, for
example, the acetic acid esters, mixed C3-C8 fatty acid
esters, or the C~ 3 OXO acid diester of tetraethylene glycol.
Another suitable class of synthetic lubrieating
oils eomprises the esters of diearkoxylie aeids (e.g.,
10 phthalie acid, succinic acid, alkyl succinic acids and
alkenyl succinic acids, maleic aeid, azelaie aeid, suberie
acia, sebacic acid, fumaric acid, adipic aeid, linoleic acid
dimer, malonie acid, alkyl malonie aeids, alkenyl malonie
aeids, ete.) with a variety of alcohols (e.g., butyl aleohol,
15 hexyl alcohol, dodecyl alcohol, ~-ethylhexyl alcohol,
ethylene glycol, diethylene glycol monoether, propylene
glyeol, ete.). Speeifie examples of these esters inelude
dibutyl adipate, di(2-ethylhexyl) sebaeate, di-n-hexyl
fumarate, dioetyl sebaeate, diisooetyl azelate, diisodeeyl
20 azelate, dioetyl phthalate, dideeyl phthalate, dieieosyl
sebaeate, the 2-ethylhexyl diester of linoleie aeid dimer,
the eomplex ester formed by reaeting one mole of sebaeie
aeid with two moles of tetraethylene glyeol and two moles of
2-ethylhexanoie aeid, and the like.
Esters useful as synthetie oils also inelude those
made from Cs to Cl 2 monoearboxylie aeids and polyols and
polyol ethers sueh neopentyl glyeol, trimethylolpropane,
pentaerythritol, dipentaerythritol, tripentaerythritol, ete.
Silieon-based oils sueh as the polyalkyl-, poly-
30 aryl-, polyalkoxy-, or polyaryloxy-siloxane oils and sili-
eate oil-s eomprise another useful elass of synthetie lubri-
eants ~e.g., tetraethyl silieate, tetraisopropyl silieate,
tetra-(2-ethylhexyl) silieate, tetra-(4-methyl-2-ethylhexyl)
silieate, tetra-(p-tert-butylphenyl) silieate, hexa-(4-
35 methyl-2-pentoxy)-disiloxane, poly(methyl)-siloxanes,
1138412
-23-
poly(methylphenyl)siloxanes, etc.). other synthetic lubri-
cating oils include liquid esters of phosphorus-containing
acids (e.g., tricresyl phosphate, trioctyl phosphate,
diethyl ester of decylphosphonic acid, etc.), polymeric
tetrahydrofurans and the like.
Unrefined, refined and rerefined oils (and mix-
tures of each with each other) of the type disclosed here-
inabove can be used in the lubricant compositions of the
present invention. ~nrefined oils are those obtained
10 directly from a natural or synthetic source without further
purification treatment. For example, a shale oil obtained
directly from retorting operations, a petroleum oil obtained
directly from an esterification process and used without
further treatment would be an unrefined oil. ~efined oils
15 are similar to the unrefined oils except they have been
further treated in one or more purification steps to improve
one or more properties. Many such purification techniques
are known to those of skill in the art such as solvent
extraction, acid or base extraction, filtration, percol-
20 ation, etc. Rerefined oils are obtained by processessimilar to those used to obtain refined oils applied to
refined oils which have been already used in service. Such
rerefined oils are also known as reclaimed or reprocessed
oils and often are additionally processed by techniques
25 directed to removal of spent additives and oil breakdown
products.
Generally, the lubricants of the present invention
contain an amount of the magnesium complex of~this invention
sufficient to impart detergency thereto. Normally this
30 amount will be from about 0.05% to about 20%, preferably
from about 0.5% to about 10%, of the total weight of the
lubricant. In lubricating oils operated under extremely
adverse conditions, such as lubricating oils for marine
diesel engines, the magnesium complexes of this invention
35 may be present in amounts up to about 30%.
1138~1Z
-2~-
The magnesium complexes of the present invention
are also useful as corrosion inhibitors, vanadium scavengers
and smoke suppressants in fuels. For that purpose, they are
homogeneously incorporated in minor proportions in normally
liquid fuels, usually hydrocarbonaceous fuels such as fuel
oils, bunker fuels and the like. Normally liquid fuel com-
positions comprising non-hydrocarbonaceous materials such as
alcohols, ethers, organo-nitro compounds and the like
(e.g., methanol, ethanol, diethyl ether, methyl ethyl ether,
10 nitromethane) are also within the scope of the invention as
are liquid fuels derived from vegetable or mineral sources
such as corn, alfalfa, shale and coal. Normally liquid
fuels which are mixtures of one or more hydrocarbonaceous
fuels and one or more non-hydrocarkonaceous materials are
15 also contemplated.
Generally, these fuel compositions contain an
amount of the magnesium complex sufficient to impart corro-
sion resistance thereto, suppress smoke or serve as a vana-
dium scavenger; usually this amount is from about l to about
20 10,000, preferably from about 4 to about 1000, parts thereof
by weight per million parts of fuel.
The invention also contemplates the use of other
additives in combination with the magnesium complexes.
Other additives useful in lubricants include, for example,
25 auxiliary detergents and dispersants of the ash-producing or
ashless type, corrosion- and oxidation-inhibiting agents,
pour point depressing agents, extreme pressure agents, color
stabilizers and anti-foam agents.
The auxiliary ash-producing detergents are exem-
30 plified by oil-soluble neutral and basic salts of alkali or
alkaline earth metals with sulfonic acids, carboxylic acids,
or organic phosphorus acids characterized by at least one
direct carbon-to-phosphorus linkage such as those prepared
by the treatment of an olefin polymer (e.g., polyisobutene
35 having a molecular weight of 1000) with a phosphorizing
lZ
-25-
agent such as phosphorus trichloride, phosphorus hepta-
sulfide, phosphorus pentasulfide, phosphorus trichloride and
sulfur, white phosphorus and a sulfur halide, or phosphoro-
thioic chloride. The most commonly used salts of such acids
are those of sodium, potassium, lithium, calcium, magnesium,
strontium and barium.
The term "basic salt" is used to designate metal
salts wherein the metal is present in stoichiometrically
larger amounts than the organic acid radical. The commonly
10 employed methods for preparing the basic salts involve heat-
ing a mineral oil solution of an acid with a stoichiometric
excess of a metal neutralizing agent such as the metal
oxide, hydroxide, carbonate, bicarbonate, or sulfide at a
temperature above 50C. and filtering the resulting mass.
15 The use of a "promoter" in the neutralization step to aid
the incorporation of a large excess of metal likewise is
known. Examples of compounds useful as the promoter include
phenolic substances such as phenol, naphthol, alkylphenol,
thiophenol, sulfurized alkylphenol, and condensation pro-
20 ducts of formaldehyde with a phenolic substance; alcoholssuch as methanol, 2-propanol, octyl alcohol, cellosolve,
carbitol, ethylene glycol, stearyl alcohol, and cyclohexyl
alcohol; and amines such as aniline, phenylenediamine,
phenothiazine, phenyl-~-naphthylamine, and dodecylamine. A
25 particularly effective method for preparing the basic salts
comprises mixing an acid with an excess of a basic alkaline
earth metal neutralizing agent and at least one alcohol
promoter, and carbonating the mixture at an elevated tem-
perature such as 60-200C.
Ashless detergents and dispersants are so called
despite the fact that, depending on its constitution, the
dispersânt may upon combustion yield a non-volatile material
such as boric oxide or phosphorus pentoxide; however, it
does not ordinarily contain metal and therefore does not
35 yield a metal-containing ash on combustion. Many types are
113841Z
known in the art, and any of them are suitable for use in
the lubricants of this invention. The following are illus-
trative:
(1) Reaction products of carboxylic acids (or
derivatives thereof) containing at least about 34 and pre-
ferably at least about 54 carbon atoms with nitrogen-con-
taining compounds such as amine, organic hydroxy compounds
such as phenols and alcohols, and/or basic inorganic mater-
ials. Examples of these "carboxylic dispersants" are
10 described in British Patent 1,306,529 and in many U.S.
patents including the following:
3,163,603 3,351,552 3,541,012
3,184,474 3,381,022 3,542,678
3,215,707 3,399,1~1 3,542,680
15 3,219,666 3,415,750 3,567,637
3,271,310 3,433,744 3,574,101
3,272,746 3,444,170 3,576,743
3,281,357 3,448,048 3,630,904
3,306,908 3,448,049 3,632,510
20 3,311,558 3,451,933 3,632,511
3,316,177 3,454,607 3,697,428
3,340,281 3,467,668 3,725,441
3,341,542 3,501,405 Re 26,433
3,346,493 3,522,179
(2) Reaction products of relatively high molecu-
lar weight aliphatic or alicyclic halides with amines, pre-
ferably polyalkylene polyamines. These may be characterized
as "amine dispersants" and examples thereof ar`e described
for example, in the following U.S. patents:
3,275,554 3,454,555
3,438,757 3,565,804
(3) Reaction products of alkyl phenols in which
the alkyl group contains at least about 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
35 polyalkylene polyamines), which may be characterized as
1~3841Z
- 27 -
"Mannich dispersants". The materials described in the
following U.S. patents are illustrative:
3,413,347 3,725,480
3,697,574 3,726,882
3,725,277
(4) Products obtained by post-treating the car-
boxylic, amine or Mannich dispersants with such reagents as
urea, thiourea, carbon disulfide, aldehydes, ketones, car-
boxylic acids, hydrocarbon-substituted succinic anhyrides,
nitriles, epoxides, boron compounds, phosphorus compounds or
the like. Exemplary materials of this kind are described in
the following U.S. patents:
3,036,003 3,282,955 3,493,520 3,639,~42
3,087,936 3,312,619 3,502,677 3,649,229
3,200,107 3,366,569 3,513,093 3,649,659
3,216,936 3,367,943 3,533,945 3,658,836
3,254,025 3,373,111 3,539,633 3,697,574
3,256,185 3,403,102 3,573,010 3,702,757
3,278,550 3,442,808 3,579,450 3,703,536 -
3,280,234 3,455,831 3,591,598 3,704,308
3,281,428 3,455,832 3,600,372 3,708,522
(5) Interpolymers of oil-solubilizing monomers
such as decyl methacrylate, vinyl decyl ether and high
molecular weight olefins with monomers containing polar
substituents, e.g. aminoalkyl acrylates or acrylamides and
poly-(oxyethylene)-substituted acrylates. Thes~ may be
characterized as "polymeric dispersants" and examples there-
of are disclosed in the following U.S. patents:
3,329,658 3,666,730
3,449,250 3,687,849
3,519,565 3,702,300
The above-noted patents disclose ashless dispersants.
Extreme pressure agents and corrosion- and oxida-
tion-inhibiting agents are exemplified by chlorinated ali-
~"~ ., .
~, , .
:
'1138~1Z
-28-
phatic hydrocarbons such as chlorinated wax; organic sul-
fides and polysulfides such as benzyl disulfide, bis(chloro-
benzyl)disulfide, dibutyl tetrasulfide, sulfurized methyl
ester of oleic acid, sulfurized alkylphenol, sulfurized
dipentene, and sulfurized terpene; phosphosulfurized hy-
drocarbons such as the reaction product of a phosphorus
sulfide with turpentine or methyl oleate; phosphorus esters
including principally dihydrocarbon and trihydrocarbon
phosphites such as dibutyl phosphite, diheptyl phosphite,
10 dicyclohe~yl phosphite, pentylphenyl phosphite, dipentyl-
phenyl phosphite, tridecyl phosphite, distearyl phosphite,
dimethyl naphthyl phosphite, oleyl 4-pentylphenyl phosphite,
polypropylene (molecular weight 500)-substituted phenyl
phosphite, diisobutyl-substituted phenyl phosphite; metal
15 thiocarbamates, such as zinc dioctyldithiocarbamate, and
barium heptylphenyl dithiocarbamate; Group II metal phos-
phorodithioates such as zinc dicyclohexylphosphorodithioate,
zine dioetylphosphorodithioate, barium di(heptylphenyl)-
phosphorodithioate, cadmium dinonylphosphorodithioate, and
20 the zinc salt of a phosphorodithioic acid produced by the
reaction of phosphorus pentasulfide with an equimolar
mixture of isopropyl alcohol and n-hexyl alcohol.
Other additives useful in fuels include deposit
preventers or modifiers sueh as triaryl phosphates, ayes,
25 cetane improvers, antioxidants such as 2,6-di-tertiary-
butyl-4-methylphenol, rust inhibitors such as alkylated
succinic acids and anhydrides, baeteriostatic agents, gum
inhibitors, metal deactivators, demulsifiers and the like.
The magnesium complexes of this invention can be
30 added directly to the lubricant or fuel. Preferably, how-
ever, they are diluted with a substantially inert, normally
liquid organic diluent sueh as those mentioned hereinabove,
partieularly mineral oil, naphtha, benzene, toluene or
xylene, to form an additive eoneentrate. These coneentrates
35 generally eontain about 20-90~ by weight of the magnesium
113B4~%
- 29 -
complex and may con-tain in addition, one or more of the
other additives described hereinabove.
Corrosion-Resistant Coatin~s and Other Uses -
The thixo-trop~ magnesium complexes of -this inven-
tion, especially those that are viscous or solid at ambient
temperatures, are useful as corrosion-resistant coatings for
metal (e.g. ferrous metal, galvanized, aluminum or mag-
nesium) surfaces, especially in the nature of undercoats for
automotive bodies, coatings for structural members such as
automotive frames, and the like. They may be employed as
such alone or in combination with various adjuvants known to
be useful in such coatings, such as other basic metal sul-
fonates lof the type disclosed in U.S. Patent 3,453,124),
acidic phosphate esters, and waxes and resins as disclosed
hereinabove with reference to component D.
For coating automotive frames and the like, a
solid "hot melt" composition is suitable. Frequently, a dye
or pigment is added to the "hot melt" composition.
For corrosion-inhibiting purposes, the viscoùs or
solid composition of this invention may be applied to the
metal surface by any ordinary method such as brushing,
spraying, dip-coating, flow-coating, roller-coating and the
like, with heating if necessary (as to liquefy a solid
composition). The viscosity may be adjusted for the par-
ticular method of application selected by adding, if neces-
sary, a diluent which may be a substantially inert, normally
liquid inorganic diluent, an analogous solid, or a mixture of
liquids and solids; suitable materials are described herein-
above with reference to component D. The coated metal
surface may then be dried either by exposure to air or by
baking, although drying frequently takes place without a
separate drying step. If the coating composition is of a
~384~Z
-30-
suitable viscosity to allow direct applieation to the metal
surface, no solvent is used and no drying procedure need ke
followed. A more viscous grease ean be diluted to produee a
less viscous grease which is suitable for application as
previously noted. The film thic~ness is not eritieal al-
though a eoating of about 50-2000 mg. per square foot of
surfaee in the ease of an undereoat, and up to about 10,000
mg. per square foot in the ease of a eoating for frames or
other struetural members, is usually suffieient to provide
10 adequate protection. Heavier coatings can be used if
desired, but they normally contribute little in the way of
additional protection.
The magnesium eomplexes of this invention are also
useful as lubrieant greases and as stabilizers for resinous
15 eompositions, typieally polyvinyl ehloride, to proteet them
against oxidative degradation.
