U.S. patent application number 10/911956 was filed with the patent office on 2006-02-09 for lubricating oil additive concentrates.
Invention is credited to Rolfe J. Hartley.
Application Number | 20060030498 10/911956 |
Document ID | / |
Family ID | 35240859 |
Filed Date | 2006-02-09 |
United States Patent
Application |
20060030498 |
Kind Code |
A1 |
Hartley; Rolfe J. |
February 9, 2006 |
Lubricating oil additive concentrates
Abstract
Lubricant additive concentrates containing an admixture of at
least one basic metal complex and at least one surface active agent
having at least one hydroxyl or amino group, in which the metal
basic metal complex is preblended with a polyalkenyl acylating
agent prior to admixture with the surface active agent.
Inventors: |
Hartley; Rolfe J.;
(Rockaway, NJ) |
Correspondence
Address: |
Infineum USA L.P.;Law Department
1900 East Linden Avenue
P.O. Box 710
Linden
NJ
07036-0710
US
|
Family ID: |
35240859 |
Appl. No.: |
10/911956 |
Filed: |
August 5, 2004 |
Current U.S.
Class: |
508/232 |
Current CPC
Class: |
C10M 2219/046 20130101;
C10N 2030/00 20130101; C10M 2215/225 20130101; C10N 2040/25
20130101; C10M 2207/26 20130101; C10N 2020/04 20130101; C10M
2207/028 20130101; C10M 2207/129 20130101; C10M 177/00 20130101;
C10M 2207/289 20130101; C10M 2215/042 20130101; C10N 2010/04
20130101; C10M 163/00 20130101; C10N 2060/00 20130101; C10M
2207/262 20130101 |
Class at
Publication: |
508/232 |
International
Class: |
C10L 1/22 20060101
C10L001/22 |
Claims
1. A lubricating oil additive concentrate comprising oil of
lubricating viscosity, a basic metal complex, a polyalkenyl
acylating agent, and a surface active agent containing at least one
hydroxyl or amino group, wherein said basic metal complex is
premixed with said polyalkenyl acylating agent prior to
incorporation into said concentrate.
2. A concentrate, as claimed in claim 1, wherein said basic metal
complex is an overbased metal detergent.
3. A concentrate, as claimed in claim 2, wherein said overbased
metal detergent is selected from the group consisting of overbased
calcium sulfonates, overbased magnesium sulfonates, overbased
calcium phenates, overbased magnesium phenates, overbased calcium
carboxylates, overbased magnesium carboxylates, overbased calcium
hybrid detergents containing surfactant systems comprising at least
two of sulfonate, phenate and carboxylate surfactant, overbased
magnesium hybrid detergents containing surfactant systems
comprising at least two of sulfonate, phenate and carboxylate
surfactant, and mixtures thereof.
4. A concentrate, as claimed in claim 2, wherein said overbased
metal detergent is an overbased calcium detergent.
5. A concentrate, as claimed in claim 2, wherein said overbased
metal detergent is an overbased metal sulfonate detergent, or an
overbased metal hybrid detergent containing a surfactant system
comprising sulfonate surfactant and at least one other
surfactants.
6. A concentrate, as claimed in claim 2, wherein said overbased
metal detergent is an overbased calcium sulfonate detergent, or an
overbased calcium hybrid detergent containing a surfactant system
comprising sulfonate surfactant and at least one other
surfactants.
7. A concentrate, as claimed in claim 1, wherein said polyalkenyl
acylating agent is a polyalkenyl substituted mono- or dicarboxylic
acid or anhydride producing material.
8. A concentrate, as claimed in claim 7, wherein said polyalkenyl
substituted mono- or dicarboxylic acid or anhydride producing
material is polyisobutenyl succinic anhydride.
9. A concentrate, as claimed in claim 8, wherein said
polyisobutenyl succinic anhydride is derived from polyisobutene
having a number average molecular weight of from about 100 to about
4000.
10. A concentrate, as claimed in claim 1, wherein said surface
active agent is selected from the group consisting of glycerol
esters of higher fatty acids; esters of long chain polycarboxylic
acids with diols; oxazoline compounds; alkoxylated
alkyl-substituted mono-amines, diamines and alkyl ether amines; and
mixtures thereof.
11. A concentrate, as claimed in claim 10, wherein said surface
active agent is selected from the group consisting of glycerol
oleates; ethoxylated amines; and mixtures thereof.
12. A concentrate, as claimed in claim 11, wherein said surface
active agent is selected from the group consisting of glycerol mono
oleate; ethoxylated tallow amine; and mixtures thereof.
13. A concentrate, as claimed in claim 1, wherein said basic metal
complex and said polyalkenyl acylating agent are premixed in a
weight ratio (basic metal complex to polyalkenyl acylating agent)
of from about 30:1 to about 1:30.
14. A concentrate, as claimed in claim 1, wherein said basic metal
complex and said polyalkenyl acylating agent are premixed at a
temperature of from about 20.degree. C. to about 250.degree. C.,
for from about 0.25 to 24 hours.
15. A concentrate, as claimed in claim 1, containing from about 3
wt. % to about 45 wt. % of the premixed basic metal complex and
polyalkenyl acylating agent; and from about 0.5 wt. % to about 20
wt. % of said surface active agent containing at least one hydroxyl
or amino group; and no more than 90 wt. % oil of lubricating
viscosity; all wt. % being based on the total weight of said
concentrate.
16. A concentrate, as claimed in claim 15, further comprising at
least one other additive selected from the group consisting of
dispersant, antioxidants and antiwear agents.
17. A concentrate, as claimed in claim 16, further comprising at
least one other component selected from the group consisting of
neutral and overbased metal detergents which have not been premixed
with a polyalkenyl acylating agent; and polyalkenyl acylating agent
which has not been premixed with overbased metal detergent.
18. A lubricating oil additive concentrate comprising: oil of
lubricating viscosity; a premix of an overbased metal detergent
selected from the group consisting of overbased calcium sulfonate
detergent; overbased calcium hybrid detergent containing a
surfactant system comprising sulfonate surfactant and at least one
other surfactants; and mixtures thereof; and polyisobutenyl
succinic anhydride; and a surface active agent selected from the
group consisting of glycerol oleates; ethoxylated amines.
19. A concentrate as claimed in claim 18, wherein said overbased
metal detergent and said polyisobutenyl succinic anhydride are
premixed in a weight ratio (overbased metal detergent and said
polyisobutenyl succinic anhydride) of from about 10:1 to about
4:1.
20. A concentrate, as claimed in claim 19, wherein said overbased
metal detergent and said polyisobutenyl succinic anhydride are
premixed at a temperature of from about 50.degree. C. to about
150.degree. C., for from about 1 to 10 hours.
21. A concentrate, as claimed in claim 18, containing from about 5
wt. % to about 30 wt. % of the premixed overbased metal detergent
and polyisobutenyl succinic anhydride; and from about 3 wt. % to
about 10 wt. % of said surface active agent; and no more than 90
wt. % oil of lubricating viscosity; all wt. % being based on the
total weight of said concentrate.
22. A concentrate, as claimed in claim 18, further comprising at
least one other additive selected from the group consisting of
dispersant, antioxidants and antiwear agents.
23. A concentrate, as claimed in claim 18, further comprising at
least one other component selected from the group consisting of
neutral and overbased metal detergents which have not been premixed
with a polyalkenyl acylating agent; and polyalkenyl acylating agent
which has not been premixed with overbased metal detergent.
24. A method of forming a stable additive concentrate comprising at
least 0.5 wt. % of a surface active agent selected from the group
consisting of glycerol oleates; ethoxylated amines and mixtures
thereof and at least 3.0 wt. % of an overbased metal detergent, and
no more than 90 wt. % of oil of lubricating viscosity which method
comprises premixing said overbased metal detergent with a
polyalkenyl acylating agent in a weight ratio (overbased metal
detergent to polyalkenyl acylating agent) of from about 30:1 to
about 1:30, to provide a premix; and admixing at least said premix,
said surface active agent and said oil of lubricating viscosity,
wherein all wt. % being based on the total weight of said
concentrate.
Description
FIELD OF THE INVENTION
[0001] The invention is directed to lubricating oil additive
concentrates useful in the formulation of lubricating oil
compositions. More specifically, the present invention is directed
to lubricating oil additive concentrates containing at least a
basic metal complex and a surface active agent having at least one
hydroxyl or amino group.
BACKGROUND OF THE INVENTION
[0002] Lubricating oil compositions for use in crankcase engine
oils comprise a major amount of base stock oil and minor amounts of
additives that improve the performance and increase the useful life
of the lubricant. Crankcase lubricating oil compositions
conventionally contain basic metal complexes, which act as
detergents and acid neutralizers, surface active agents containing
at least one hydroxyl or amino group, which function as organic
friction modifiers that are effective in improving fuel economy,
and optionally, polyalkenyl acylating agents, which can act as
compatibilizers and/or emulsifiers that ameliorate unwanted
interactions between additives. In the face of increased demands
for improved fuel economy, and further demands for reductions in
the amounts of metal (ash) contained in the lubricant, formulators
have used ever-increasing amounts of organic friction
modifiers.
[0003] Lubricating oil additives are commonly provided to lubricant
formulators in the form of 10 to 80 mass %, e.g., 20 to 80 mass %
active ingredient (AI) concentrates, which are then dissolved in
major amounts of oil of lubricating viscosity to provide a fully
formulated lubricant. The concentrates are commonly diluted in 3 to
100, e.g., 5 to 40 parts by weight of oil of lubricating viscosity,
per part by weight of the additive concentrate. As noted above,
certain lubricating oil additives are known to interact with others
in concentrates. One such known interaction occurs between organic
friction modifiers and overbased metal detergents. Specifically,
the organic friction modifiers have been found to adversely affect
the complex of the metal detergents, causing the formation of
sediment in the concentrate upon storage. The presence of a
polyalkenyl acylating agent has been found regulate this unwanted
interaction. However, as the amount of the organic friction
modifier increases to the levels now required, the effect of the
polyalkenyl acylating has become insufficient.
[0004] As lubricating oil quality standards have become more
stringent, the required amount of organic friction has increased,
and the presence of even minor amounts of sediment in additive
concentrates has become unacceptable to lubricant formulators.
Therefore, it would be advantageous to be able to provide additive
concentrates containing overbased metal detergents and high levels
of organic friction modifiers, in which the components do not
interact to form sediment.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to lubricant additive
concentrates comprising an admixture of at least one basic metal
complex and at least one surface active agent having at least one
hydroxyl or amino group, in which the basic metal complex is
preblended with a polyalkenyl acylating agent prior to admixture
with the surface active agent.
[0006] Other and further objects, advantages and features of the
present invention will be understood by reference to the following
specification.
DETAILED DESCRIPTION OF THE INVENTION
[0007] Surface active agents useful in the practice of the
invention, also hereinafter referred to as organic friction
modifiers, include oil-soluble compounds containing at least one
polar group selected from hydroxyl and amine groups, which
compounds are capable of reducing friction under hydrodynamic and
mixed hydrodynamic/boundary layer conditions. Examples of such
materials include glycerol esters of higher fatty acids, for
example, glycerol mono-oleate; esters of long chain polycarboxylic
acids with diols, for example, the butane diol ester of a dimerized
unsaturated fatty acid; oxazoline compounds; and alkoxylated
alkyl-substituted mono-amines, diamines and alkyl ether amines, for
example, ethoxylated tallow amine and ethoxylated tallow ether
amine. Particularly preferred surface active agents include
glycerol oleates, particularly glycerol monooleate, and ethoxylated
amines, particularly ethoxylated tallow amine. Because adverse
interactions are more severe when elevated levels of surface active
agent are present in the concentrate, in a preferred embodiment,
the concentrate of the present invention contains at least 3 wt. %,
preferably at least 5 wt. %, of surface active agent, based on the
total weight of the additive concentrate. In alternative terms,
concentrates that contain the surface active agent in an amount
sufficient to provide a formulated lubricant with at least 0.5 wt.
% of surface active agent after dilution are preferred.
[0008] Basic metal complexes useful in the context of the invention
function as both detergents to reduce or remove deposits and as
acid neutralizers or rust inhibitors, thereby reducing wear and
corrosion and extending engine life. Detergents generally comprise
a polar head with a long hydrophobic tail. The polar head comprises
a metal salt of an acidic organic compound. The salts may contain a
substantially stoichiometric amount of the metal in which case they
are usually described as normal or neutral salts, and would
typically have a total base number or TBN (as can be measured by
ASTM D2896) of from 0 to 80. A large amount of a metal base may be
incorporated by reacting excess metal compound (e.g., an oxide or
hydroxide) with an acidic gas (e.g., carbon dioxide). The resulting
overbased detergent comprises neutralized detergent as the outer
layer of a metal base (e.g. carbonate) micelle. Such overbased
detergents may have a TBN of 150 or greater, and typically will
have a TBN of from 250 to 450 or more.
[0009] Detergents that may be used include oil-soluble neutral and
overbased sulfonates, phenates, sulfurized phenates,
thiophosphonates, salicylates, and naphthenates and other
oil-soluble carboxylates of a metal, particularly the alkali or
alkaline earth metals, e.g., barium, sodium, potassium, lithium,
calcium, and magnesium. The most commonly used metals are calcium
and magnesium, which may both be present in detergents used in a
lubricant, and mixtures of calcium and/or magnesium with sodium.
Particularly convenient metal detergents are neutral and overbased
calcium sulfonates having TBN of from 20 to 450, neutral and
overbased calcium phenates and sulfurized phenates having TBN of
from 50 to 450 and neutral and overbased magnesium or calcium
salicylates having a TBN of from 20 to 450. Combinations of
detergents, whether overbased or neutral or both, may be used.
[0010] Sulfonates may be prepared from sulfonic acids which are
typically obtained by the sulfonation of alkyl substituted aromatic
hydrocarbons such as those obtained from the fractionation of
petroleum or by the alkylation of aromatic hydrocarbons. Examples
included those obtained by alkylating benzene, toluene, xylene,
naphthalene, diphenyl or their halogen derivatives such as
chlorobenzene, chlorotoluene and chloronaphthalene. The alkylation
may be carried out in the presence of a catalyst with alkylating
agents having from about 3 to more than 70 carbon atoms. The
alkaryl sulfonates usually contain from about 9 to about 80 or more
carbon atoms, preferably from about 16 to about 60 carbon atoms per
alkyl substituted aromatic moiety.
[0011] The oil soluble sulfonates or alkaryl sulfonic acids may be
neutralized with oxides, hydroxides, alkoxides, carbonates,
carboxylate, sulfides, hydrosulfides, nitrates, borates and ethers
of the metal. The amount of metal compound is chosen having regard
to the desired TBN of the final product but typically ranges from
about 100 to 220 wt. % (preferably at least 125 wt. %) of that
stoichiometrically required.
[0012] Metal salts of phenols and sulfurized phenols are prepared
by reaction with an appropriate metal compound such as an oxide or
hydroxide and neutral or overbased products may be obtained by
methods well known in the art. Sulfurized phenols may be prepared
by reacting a phenol with sulfur or a sulfur containing compound
such as hydrogen sulfide, sulfur monohalide or sulfur dihalide, to
form products which are generally mixtures of compounds in which 2
or more phenols are bridged by sulfur containing bridges.
[0013] Carboxylate detergents, e.g., salicylates, can be prepared
by reacting an aromatic carboxylic acid with an appropriate metal
compound such as an oxide or hydroxide and neutral or overbased
products may be obtained by methods well known in the art. The
aromatic moiety of the aromatic carboxylic acid can contain
heteroatoms, such as nitrogen and oxygen. Preferably, the moiety
contains only carbon atoms; more preferably the moiety contains six
or more carbon atoms; for example benzene is a preferred moiety.
The aromatic carboxylic acid may contain one or more aromatic
moieties, such as one or more benzene rings, either fused or
connected via alkylene bridges. The carboxylic moiety may be
attached directly or indirectly to the aromatic moiety. Preferably
the carboxylic acid group is attached directly to a carbon atom on
the aromatic moiety, such as a carbon atom on the benzene ring.
More preferably, the aromatic moiety also contains a second
functional group, such as a hydroxy group or a sulfonate group,
which can be attached directly or indirectly to a carbon atom on
the aromatic moiety.
[0014] Preferred examples of aromatic carboxylic acids are
salicylic acids and sulfurized derivatives thereof, such as
hydrocarbyl substituted salicylic acid and derivatives thereof.
Processes for sulfurizing, for example a hydrocarbyl-substituted
salicylic acid, are known to those skilled in the art. Salicylic
acids are typically prepared by carboxylation, for example, by the
Kolbe-Schmitt process, of phenoxides, and in that case, will
generally be obtained, normally in a diluent, in admixture with
uncarboxylated phenol.
[0015] Preferred substituents in oil-soluble salicylic acids are
alkyl substituents. In alkyl-substituted salicylic acids, the alkyl
groups advantageously contain 5 to 100, preferably 9 to 30,
especially 14 to 20, carbon atoms. Where there is more than one
alkyl group, the average number of carbon atoms in all of the alkyl
groups is preferably at least 9 to ensure adequate oil
solubility.
[0016] Detergents generally useful in the formulation of
lubricating oil compositions also include "hybrid" detergents
formed with mixed surfactant systems, e.g., phenate/salicylates,
sulfonate/phenates, sulfonate/salicylates, and
sulfonate/phenate/salicylates, as described, for example, in
pending U.S. patent application Ser. Nos. 09/180,435 and 09/180,436
and U.S. Pat. Nos. 6,153,565 and 6,281,179.
[0017] Interaction with surface active agents in lubricating
additive concentrates is particularly severe when the metal of the
metal complex is calcium. Further, the interaction with the surface
active agent is more pronounced in concentrates containing
sulfonate detergents and complex detergents containing sulfonate
surfactant. Therefore, in a preferred embodiment, the basic metal
complex is calcium overbased detergent or overbased sulfonate or
sulfonate-containing complex detergent, more preferably overbased
calcium sulfonate or sulfonate-containing complex detergent.
[0018] Polyalkenyl acylating agents useful in the practice of the
invention include polyalkenyl substituted olefinic mono- and
dicarboxylic acid and anhydride producing materials. Preferred
polyalkenyl moieties are derived from .alpha.-olefin homopolymers,
.alpha.-olefin copolymers, and ethylene-.alpha.-olefin copolymers.
The .alpha.-olefin homo- and copolymers are respectively polymers
of one and of at least two C.sub.3 to C.sub.12 .alpha.-olefin(s)
having the formula CH.sub.2.dbd.CHR', wherein R' is a straight or
branched chain alkyl radical comprising 1 to 10 carbon atoms. The
unsaturated ethylene-.alpha.-olefin copolymers are polymers of
ethylene and at least one .alpha.-olefin of the above formula. The
.alpha.-olefins employed in the foregoing homo- and copolymers are
more preferably selected from the C.sub.3 to C.sub.6
.alpha.-olefins of the above formula, R' being a straight or
branched chain alkyl of from 1 to 4 carbon atoms. Accordingly,
useful .alpha.-olefin monomers and comonomers include, for example,
propene, butene-1, hexene-1, octene-1,4-methylpentene-1, decene-1,
dodecene-1, and mixtures thereof (e.g., mixtures of propene and
butene-1). Exemplary of such polymers are propene homopolymers,
butene-1 homopolymers, ethylene-propene copolymers and the like. A
preferred class of polymers are those derived from ethylene and the
C.sub.3 and C.sub.4 .alpha.-olefins of the above formula; i.e.,
polyethylene, polypropene, polybutene-1, and copolymers of ethylene
and propene, ethylene and butene-1, butene-1 and propene, and
ethylene and propene and butene-1.
[0019] The polyalkenyl moieties from which the polyalkenyl
acylating agent is derived can have a number average molecular
weight in the range of from about 100 to 4000, preferably from
about 450 to 2500, and more preferably from about 750 to 1500.
Number average molecular weight (M.sub.n) can be determined by
several known techniques such as gel permeation chromatography
("GPC"), vapor phase osmometry, proton NMR and carbon-13 NMR.
Particularly preferred polyalkenes are polyisobutenes and
polybutenes having a number average molecular weight (M.sub.n) of
from about 450 to about 2500, more preferably from about 750 to
1500.
[0020] Mono- and dicarboxylic acid or anhydride producing
materials, i.e., acid, anhydride, or acid ester materials from
which the polyalkenyl acylating agents may be derived include (i)
monounsaturated C.sub.4 to C.sub.10 dicarboxylic acid wherein (a)
the carboxyl groups are vicinyl, (i.e., located on adjacent carbon
atoms) and (b) at least one, preferably both, of said adjacent
carbon atoms are part of said mono unsaturation; (ii) derivatives
of (i) such as anhydrides or C.sub.1 to C.sub.5 alcohol derived
mono- or diesters of (i); (iii) monounsaturated C.sub.3 to C.sub.10
monocarboxylic acid wherein the carbon-carbon double bond is
conjugated with the carboxyl group, i.e., of the structure
--C.dbd.C--CO--; and (iv) derivatives of (iii) such as C.sub.1 to
C.sub.5 alcohol derived mono- or diesters of (iii). Mixtures of
compounds (i) to (iv) may also be used. Upon reaction with the
backbone, the monounsaturation of the reactant mono- or
dicarboxylic acid or anhydride material becomes saturated. Thus,
for example, maleic anhydride becomes backbone-substituted succinic
anhydride, and acrylic acid becomes backbone-substituted propionic
acid. Exemplary of such monounsaturated carboxylic reactants are
fumaric acid, itaconic acid, maleic acid, maleic anhydride,
chloromaleic acid, chloromaleic anhydride, acrylic acid,
methacrylic acid, crotonic acid, cinnamic acid, and lower alkyl
(e.g., C.sub.1 to C.sub.4 alkyl) acid esters of the foregoing,
e.g., methyl maleate, ethyl fumarate, and methyl fumarate. A
particularly preferred mono- or dicarboxylic acid or anhydride
material is maleic anhydride and the preferred polyalkenyl
acylating agent is polyisobutenyl succinic anhydride (PIBSA).
[0021] The polyalkenyl acylating agent and basic metal complex are
premixed prior to contact with the surface active agent containing
at least one hydroxyl or amino group. Preferably, the basic metal
complex is premixed with the polyalkenyl acylating agent at an
elevated temperature, such as from about 20 to about 250.degree.
C., preferably from about 50 to about 150.degree. C., more
preferably from about 75 to about 125.degree. C., for a period of
time, such as from about 0.25 to 24 hours, preferably from about 1
to 10 hours, more preferably from about 2 to 5 hours.
[0022] The basic metal complex and polyalkenyl acylating agent may
be premixed in a wt. % ratio of basic metal complex to polyalkenyl
acylating agent of from about 30:1 to about 1:30, preferably from
about 20:1 to about 0.5:1, such as from about 20:1 to about 1:1,
more preferably from about 10:1 to about 4:1.
[0023] The premixed polyalkenyl acylating agent and basic metal
complex can be added to a concentrate containing additives
including the hydroxyl or amino group-containing surface active
agent. Alternatively, the premixed polyalkenyl acylating agent and
basic metal complex or polyalkenyl acylated agent-treated basic
metal complex, may be used to form a concentrate containing
additives excluding the hydroxyl or amino group-containing-surface
active agent, to which the surface active agent is subsequently
introduced.
[0024] The concentrates of the invention are preferably prepared at
an elevated temperature, i.e. above ambient temperature. Such
concentrates may be prepared at a temperature of at least
50.degree. C. such as at least 80.degree. C., preferably at least
90.degree. C., more preferably at least 100.degree. C. Although
energy is saved at low temperatures, practical considerations
dictate the most convenient temperature that can be used. Thus,
where any additive is used that is solid at ambient temperature, it
is usually more convenient to raise the temperature to a
temperature at which the additive flows, rather than dissolving it
in oil prior to addition to the other additives. Temperatures of
100.degree. C. or more can be employed if any additive is more
conveniently handled at such temperatures. Consideration must be
given to the time for which it is held at the mixing temperature
and its stability under such temperatures and time conditions.
[0025] In order for the concentrate to be oleaginous, the additives
may be in solution in an oleaginous carrier or such a carrier may
be provided separately or both. Examples of suitable carriers are
oils of lubricating viscosity, such as described in detail
hereinafter, and aliphatic, naphthenic and aromatic
hydrocarbons.
[0026] The components are advantageously held at the mixing
temperature for a time sufficient to achieve a homogenous mixture
thereof. This can usually be accomplished within one half hour,
particularly when the temperature of mixing exceeds 80.degree.
C.
[0027] The concentrates of the invention can be incorporated into a
lubricating oil composition in any convenient way. Thus, they can
be added directly to an oil of lubricating viscosity by dispersing
or dissolving them in the oil at the desired concentrations of the
dispersant and detergent, respectively. Such blending can occur at
ambient temperature or elevated temperatures. Alternatively, the
composite can be blended with a suitable oil-soluble solvent and
base oil to form a further concentrate which is then blended with
an oil of lubricating viscosity to obtain the final lubricating oil
composition. Such concentrate will typically contain (on an active
ingredient (A.I.) basis) from about 0.5 wt. % to about 20 wt. %,
preferably from about 1 wt. % to about 15 wt. %, more preferably
from about 3 wt. % to about 10 wt. %, of the surface active agent
containing at least one hydroxyl or amino group, and from 3 to 45
wt. %, preferably from 5 to 30 wt. %, more preferably from about
7.5 wt. % to about 25 wt. % of the premixed polyalkenyl acylating
agent and basic metal complex, based on the concentrate weight; the
remainder of the concentrate comprising diluent (preferably no more
than 90 wt. %, such as not more than 80 wt. %) oil and, optionally,
other additives.
[0028] The oil of lubricating viscosity, useful for making
concentrates of the invention or for making lubricating oil
compositions therefrom, may be selected from natural (vegetable,
animal or mineral) and synthetic lubricating oils and mixtures
thereof. It may range in viscosity from light distillate mineral
oils to heavy lubricating oils such as gas engine oil, mineral
lubricating oil, motor vehicle oil, and heavy duty diesel oil.
Generally, the viscosity of the oil ranges from 2 centistokes to 30
centistokes, especially 5 centistokes to 20 centistokes, at
100.degree. C.
[0029] Natural oils include animal oils and vegetable oils (e.g.,
castor oil, lard oil); liquid petroleum oils and hydro-refined,
solvent-treated or acid-treated mineral oils of the paraffinic,
naphthenic and mixed paraffinic-naphthenic types. Oils of
lubricating viscosity derived from coal or shale also serve as
useful base oils.
[0030] Synthetic lubricating oils include hydrocarbon oils and
halo-substituted hydrocarbon oils such as polymerized and
interpolymerized olefins (e.g., polybutylenes, polypropylenes,
propylene-isobutylene copolymers, chlorinated polybutylenes,
poly(1-hexenes), poly(1-octenes), poly(1-decenes)); alkylbenzenes
(e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,
di(2-ethylhexyl)benzenes); polyphenyls (e.g., biphenyls,
terphenyls, alkylated polyphenols); and alkylated diphenyl ethers
and alkylated diphenyl sulfides and derivative, analogs and
homologs thereof.
[0031] Alkylene oxide polymers and interpolymers and derivatives
thereof where the terminal hydroxyl groups have been modified by
esterification, etherification, etc., constitute another class of
known synthetic lubricating oils. These are exemplified by
polyoxyalkylene polymers prepared by polymerization of ethylene
oxide or propylene oxide, and the alkyl and aryl ethers of
polyoxyalkylene polymers (e.g., methyl-polyiso-propylene glycol
ether having a molecular weight of 1000 or diphenyl ether of
poly-ethylene glycol having a molecular weight of 1000 to 1500);
and mono- and polycarboxylic esters thereof, for example, the
acetic acid esters, mixed C.sub.3-C.sub.8 fatty acid esters and
C.sub.13 Oxo acid diester of tetraethylene glycol.
[0032] Another suitable class of synthetic lubricating oils
comprises the esters of dicarboxylic acids (e.g., phthalic acid,
succinic acid, alkyl succinic acids and alkenyl succinic acids,
maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric
acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic
acids, alkenyl malonic acids) with a variety of alcohols (e.g.,
butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl
alcohol, ethylene glycol, diethylene glycol monoether, propylene
glycol). Examples of such esters include dibutyl adipate,
di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate,
diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl
phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic
acid dimer, and the complex ester formed by reacting one mole of
sebacic acid with two moles of tetraethylene glycol and two moles
of 2-ethylhexanoic acid.
[0033] Esters useful as synthetic oils also include those made from
C.sub.5 to C.sub.12 monocarboxylic acids and polyols and polyol
esters such as neopentyl glycol, trimethylolpropane,
pentaerythritol, dipentaerythritol and tripentaerythritol.
[0034] Silicon-based oils such as the polyalkyl-, polyaryl-,
polyalkoxy- or polyaryloxysilicone oils and silicate oils comprise
another useful class of synthetic lubricants; such oils include
tetraethyl silicate, tetraisopropyl silicate,
tetra-(2-ethylhexyl)silicate,
tetra-(4-methyl-2-ethylhexyl)silicate, tetra-(p-tert-butyl-phenyl)
silicate, hexa-(4-methyl-2-ethylhexyl)disiloxane,
poly(methyl)siloxanes and poly(methylphenyl)siloxanes. Other
synthetic lubricating oils include liquid esters of
phosphorous-containing acids (e.g., tricresyl phosphate, trioctyl
phosphate, diethyl ester of decylphosphonic acid) and polymeric
tetrahydrofurans.
[0035] The oil of lubricating viscosity may comprise a Group I,
Group II, Group III, Group IV or Group V oil or blends of the
aforementioned oils. The oil of lubricating viscosity may also
comprise a blend of a Group I oil and one or more of Group II,
Group III, Group IV or Group V oil.
[0036] Definitions for the oils as used herein are the same as
those found in the American Petroleum Institute (API) publication
"Engine Oil Licensing and Certification System", Industry Services
Department, Fourteenth Edition, December 1996, Addendum 1, December
1998. Said publication categorizes oils as follows: [0037] a) Group
I oils contain less than 90 percent saturates and/or greater than
0.03 percent sulfur and have a viscosity index greater than or
equal to 80 and less than 120 using the test methods specified in
Table 1. [0038] b) Group II oils contain greater than or equal to
90 percent saturates and less than or equal to 0.03 percent sulfur
and have a viscosity index greater than or equal to 80 and less
than 120 using the test methods specified in Table 1. Although not
a separate Group recognized by the API, Group II oils having a
viscosity index greater than about 110 are often referred to as
"Group II+" oils. [0039] c) Group III oils contain greater than or
equal to 90 percent saturates and less than or equal to 0.03
percent sulfur and have a viscosity index greater than or equal to
120 using the test methods specified in Table 1. [0040] d) Group IV
oils are polyalphaolefins (PAO).
[0041] e) Group V oils are all other base stocks not included in
Group I, II, III, or IV. TABLE-US-00001 TABLE 1 Property Test
Method Saturates ASTM D2007 Viscosity Index ASTM D2270 Sulfur ASTM
D4294
[0042] The oil of lubricating viscosity preferably has a saturate
content of at least 65%, more preferably at least 75%, such as at
least 85%. Most preferably, the oil of lubricating viscosity has a
saturate content of greater than 90%. Preferably, the oil of
lubricating viscosity has a sulfur content of less than 1%,
preferably less than 0.6%, more preferably less than 0.3%, by mass,
such as 0 to 0.3% by mass.
[0043] Preferably the volatility of the oil of lubricating
viscosity, as measured by the Noack test (ASTM D5880), is less than
or equal to about 40%, such as less than or equal to about 35%,
preferably less than or equal to about 32%, such as less than or
equal to about 28%, more preferably less than or equal to about
16%. Preferably, the viscosity index (VI) of the oil of lubricating
viscosity is at least 85, preferably at least 100, most preferably
from about 105 to 140.
[0044] In addition to the mixed basic metal complex/polyalkenyl
acylating agent and organic friction modifier, a concentrate, and
fully formulated lubricants formed therefrom, can contain a number
of other performance improving additives selected from ashless
dispersants, antiwear agents, oxidation inhibitors or antioxidants,
metal-containing friction modifiers and fuel economy agents,
antifoamants and corrosion inhibitors, including additional amounts
of metal detergent and polyalkenyl acylating agent (independent of
the premixed polyalkenyl acylating agent and basic metal complex).
Conventionally, when formulating a lubricant, the additives will be
provided to the formulator in one or more, preferably a single
concentrated additive package, oftentimes referred to as a DI
(dispersant-inhibitor) package and a VI improver and/or VI improver
and LOFI, will be provided in a second package.
[0045] Ashless dispersants maintain in suspension oil insolubles
resulting from oxidation of the oil during wear or combustion. They
are particularly advantageous for preventing the precipitation of
sludge and the formation of varnish, particularly in gasoline
engines.
[0046] Dihydrocarbyl dithiophosphate metal salts are frequently
used as antiwear and antioxidant agents. The metal may be an alkali
or alkaline earth metal, or aluminum, lead, tin, molybdenum,
manganese, nickel or copper. The zinc salts are most commonly used
in lubricating oil and may be prepared in accordance with known
techniques by first forming a dihydrocarbyl dithiophosphoric acid
(DDPA), usually by reaction of one or more alcohol or a phenol with
P.sub.2S.sub.5 and then neutralizing the formed DDPA with a zinc
compound. For example, a dithiophosphoric acid may be made by
reacting mixtures of primary and secondary alcohols. Alternatively,
multiple dithiophosphoric acids can be prepared where the
hydrocarbyl groups on one are entirely secondary in character and
the hydrocarbyl groups on the others are entirely primary in
character. To make the zinc salt, any basic or neutral zinc
compound could be used but the oxides, hydroxides and carbonates
are most generally employed. Commercial additives frequently
contain an excess of zinc due to the use of an excess of the basic
zinc compound in the neutralization reaction.
[0047] Oxidation inhibitors or antioxidants reduce the tendency of
mineral oils to deteriorate in service. Oxidative deterioration can
be evidenced by sludge in the lubricant, varnish-like deposits on
the metal surfaces, and by viscosity growth. Such oxidation
inhibitors include hindered phenols, alkaline earth metal salts of
alkylphenolthioesters having preferably C.sub.5 to C.sub.12 alkyl
side chains, calcium nonylphenol sulfide, oil soluble phenates and
sulfurized phenates, phosphosulfurized or sulfurized hydrocarbons,
phosphorous esters, metal thiocarbamates, oil soluble copper
compounds as described in U.S. Pat. No. 4,867,890, and
molybdenum-containing compounds and aromatic amines.
[0048] Known metal-containing friction modifiers include
oil-soluble organo-molybdenum compounds. Such organo-molybdenum
friction modifiers also provide antioxidant and antiwear credits to
a lubricating oil composition. As an example of such oil soluble
organo-molybdenum compounds, there may be mentioned the
dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates,
thioxanthates, sulfides, and the like, and mixtures thereof.
Particularly preferred are molybdenum dithiocarbamates,
dialkyldithiophosphates, alkyl xanthates and
alkylthioxanthates.
[0049] Foam control can be provided by an antifoamant of the
polysiloxane type, for example, silicone oil or polydimethyl
siloxane.
[0050] Some of the above-mentioned additives can provide a
multiplicity of effects; thus for example, a single additive may
act as a dispersant-oxidation inhibitor. This approach is well
known and need not be further elaborated herein.
[0051] Representative effective amounts of such additional
additives, when used in fully formulated crankcase lubricants, are
listed below in Table 2: TABLE-US-00002 TABLE 2 Mass % ADDITIVE
(Broad) Mass % (Preferred) Ashless Dispersant 0.1-20 1-8 Metal
Detergents 0.1-15 0.2-9 Corrosion Inhibitor 0-5 0-1.5 Metal
Dihydrocarbyl Dithiophosphate 0.1-6 0.1-4 Antioxidant 0-5 0.01-2
Pour Point Depressant 0.01-5 0.01-1.5 Antifoaming Agent 0-5
0.001-0.15 Supplemental Antiwear Agents 0-1.0 0-0.5 Friction
Modifier 0-5 0-1.5 Basestock Balance Balance
[0052] This invention will be further understood by reference to
the following examples, wherein all parts are parts by weight (AI),
unless otherwise noted and which include preferred embodiments of
the invention.
EXAMPLES
[0053] A calcium sulfonate detergent having a TBN of 300 (55 wt. %
AI) was treated with polyisobutenyl succinic anhydride (PIBSA),
(PIB M.sub.n of 950; 72 wt. % A.I.), for 3 hours, at a temperature
of 100.degree. C., in the amounts shown in Table 3: TABLE-US-00003
TABLE 3 Det. No. 1 2 3 CaSulf Det. 1.60 1.60 1.60 PIBSA 0.072 0.14
0.28 Wt. % 1.672 1.74 1.88
[0054] Concentrates were formed using the above-described premixed
PIBSA/detergents, or 1.60 wt. % of the analogous untreated
detergent (Det. 4) and other additives normally provided in a
concentrated dispersant inhibitor (DI) package, in the manner
described below: TABLE-US-00004 Dis- 1.744 1.744 1.744 1.744 1.744
1.744 1.744 per- sant Anti- 0.0005 0.0005 0.0005 0.0005 0.0005
0.0005 0.0005 foam- ant Dilu- 3.01 3.01 3.01 3.01 3.01 3.01 3.01
ent blend for 0.5 hours @ 100.degree. C. and add
[0055] TABLE-US-00005 Det. 4 1.60 1.60 1.60 1.60 Det. 1 1.70 Det. 2
1.80 Det. 3 2.00 blend for 3 hours @ 100.degree. C. and add
[0056] TABLE-US-00006 Antioxidant 1.30 1.30 1.30 1.30 1.30 1.30
1.30 Mo-based 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045
Antiwear PIBSA 0.072 0.14 0.28 Diluent 0.0055 0.0055 0.0055 0.0055
0.0335 0.0655 0.1255 blend for 1 hour @ 70.degree. C. and add
[0057] TABLE-US-00007 ZDDP 0.705 0.705 0.705 0.705 0.705 0.705
0.705 Glycerol 0.60 0.60 0.60 0.60 0.60 0.60 0.60 Monooleate
Diluent 0.235 0.235 0.235 0.235 0.235 0.235 0.235 and blend for 1
hour @ 60.degree. C.
[0058] TABLE-US-00008 Conc. ID A B C D E F G Treat Rate* 9.30 9.40
9.50 9.70 9.40 9.50 9.70 Inv./Comp Comp. Inv. Inv. Inv. Comp. Comp.
Comp. *recommended amount of concentrate blended with basestock to
provide formulated lubricant
[0059] Each of the above additive concentrates was then subjected
to a storage stability test in which the concentrates were stored
for a number of weeks @ 60.degree. C. with periodic measuring of
the amount of sediment formed. A concentrate package failed the
stability test at the time the amount of sediment measured was
greater than 0.05 wt %, based on the total weight of the
concentrate. The results are provided in Table 4: TABLE-US-00009
TABLE 4 Conc. ID Week # A B C D E F G 1 Pass Pass Pass Pass Pass
Pass Pass 2 Pass Pass Pass Pass Pass Pass Pass 3 Pass Pass Pass
Pass Pass Pass Pass 4 Fail Pass Pass Pass Fail Fail Pass 5 Fail
Pass Pass Pass Fail Fail Fail 6 Fail Fail Pass Pass Fail Fail Fail
7 Fail Fail Pass Pass Fail Fail Fail 8 Fail Fail Pass Pass Fail
Fail Fail 9 Fail Fail Pass Pass Fail Fail Fail 10 Fail Fail Pass
Pass Fail Fail Fail 11 Fail Fail Pass Pass Fail Fail Fail 12 Fail
Fail Pass Pass Fail Fail Fail 13 Fail Fail Pass Pass Fail Fail
Fail
[0060] The data demonstrate that the use of a detergent treated
with even a low level of PIBSA (Inventive Conc. B) increased the
period for which the concentrate containing the high level of GMO
remained stable from 3 weeks to 5 weeks (a 66% improvement)
compared to the concentrate formed with the untreated detergent
(Comparative Conc. A). Increasing the amount of PIBSA with which
the detergent was treated further led to outstanding stability and
Inventive Conc. C and D remained stable after 13 weeks of storage.
A comparison between the Inventive Concentrates (B, C and D) and
corresponding Comparative Concentrates (E, F and G), demonstrates
that the presence of PIBSA has far less of an effect on concentrate
stability when the PIBSA is added as a separate component.
[0061] The disclosures of all patents, articles and other materials
described herein are hereby incorporated, in their entirety, into
this specification by reference. A description of a composition
comprising, consisting of, or consisting essentially of multiple
specified components, as presented herein and in the appended
claims, should be construed to also encompass compositions made by
admixing said multiple specified components. The principles,
preferred embodiments and modes of operation of the present
invention have been described in the foregoing specification. What
applicants submit is their invention, however, is not to be
construed as limited to the particular embodiments disclosed, since
the disclosed embodiments are regarded as illustrative rather than
limiting. Changes may be made by those skilled in the art without
departing from the spirit of the invention.
* * * * *