Note: Descriptions are shown in the official language in which they were submitted.
1- 133~667
EIFTn OF THE INVENTION
This invention relates to lubricating oil
compositions which exhibit marked reduction in engine
carbon deposits. More particularly, this invention is
directed to low total sulfated ash lubricating oil
compositions which are adapted for use in diesel engines
and which contain ashless dispersants, sulfurized alkyl
phenols and metal dihydrocarbyl dithiophosphates and which
are required to contain unique low levels of sulfated ash
generating additives.
BACKGROUND OF THE INVENTION
It is an objective of the industry to provide
lubricating oil compositions which exhibit improvements in
minimized engine deposits and low rates of lubricating oil
consumption, particularly in diesel engine vehicles.
Among the conventionally used lubricating oil
additives, zinc dihydrocarbyl dithiophosphates perform
multiple functions in the motor oil, namely, oxidation
inhibition, bearing corrosion inhibition, and extreme
pressure/antiwear protection for the valve train.
Early patents illustrated compositions using
polyisobutenylsuccinimide dispersants in combination with
zinc dialkyldithiophosphates which were employed in
lubricating oil compositions with other conventional
additives such as detergents, viscosity index improvers,
rust inhibitors and the like. Typical of these early
disclosures are U.S. Patents 3,018,247, 3,018,250 and
3,018,291.
~&
- 2 - 1~34667
Since phosphorus is a catalyst poison for
catalytic converters, and since the zinc itself offers a
source for sulfated ash, the art has sought to reduce or
eliminate such zinc-phosphorus-containing motor oil
components. Exemplary of prior art references directed to
the reduction in phosphorus-containing lubricant additives
are U.S. Patents 4,147,640; 4,330,420; and 4,639,324.
U.S. Patent 4,147,640 relates to lubricating oils
having improved antioxidant and antiwear properties which
are obtained by reacting an olefinic hydrocarbon having
from 6 to 8 carbon atoms and about 1 to 3 olefinic double
bonds concurrently with sulfur and hydrogen sulfide and
thereafter reacting the resulting reaction intermediate
with additional olefin hydrocarbon. These additives are
disclosed to be generally used in conjunction with other
conventional oil additives such as overbased metal
detergents, polyisobutenylsuccinimide dispersants, and
phenolic antioxidants. While it is disclosed that the
amount of the zinc additive can be greatly reduced, giving
a "low ash" or "no ash" lubricant formulation, it is
apparent the patentee was referring to Zn-derived ash, and
not total SASH levels.
U.S. Patent 4,330,420 relates to low ash, low
phosphorus motor oils having improved oxidation stability
as a result the inclusion of synergistic amounts of
dialkyldiphenylamine antioxidant and sulfurized
polyolefin. It is disclosed that the synergism between
these two additives compensates for the decreased amounts
of phosphorus in the form of zinc dithiophosphate. The
fully formulated motor oils are said to comprise 2 to 10
wt.% of ashless dispersant, 0.5 to 5 wt.% of recited
magnesium or calcium detergent salts (to provide at least
0.1% of magnesium or calcium), from 0.5 to 2.0 wt.% of zinc
dialkyldithiophosphate; from 0.2 to 2.0 wt.% of a
dialkyldiphenolamine antioxidant; from 0.2 to 4 wt.% of a
sulfurized polyolefin antioxidant; from 2 to 10 wt.% of a
_ 3 133~67
first, ethylene propylene VI improver; from 2 to 10 wt.% of
a second VI improver consisting of methacrylate terpolymer,
and the balance baseoil.
U.S. Patent 4,639,324 discloses that metal
dithiophosphate salts, while useful as antioxidants, are a
source of ash, and discloses an ashless antioxidant
comprising a reaction product made by reacting at least one
aliphatic olefinically unsaturated hydrocarbon having from
8 to 36 carbons concurrently with sulfur and at least one
fatty acid ester to obtain a reaction intermediate which is
then reacted with additional sulfur and a dimer of
cyclopentadiene or lower Cl to C4 alkyl substituted
cyclopentadiene dimers. It is disclosed that these
additives in lubricating compositions are generally used in
conjunction with other conventional oil additives such as
neutral and overbased calcium or magnesium alkaryl
sulfonates, dispersants and phenolic antioxidants. It is
disclosed that when using the additives of thiæ invention,
the amount of the zinc additive can be greatly reduced
giving a "low ash" or "no ash" lubricant formulation.
Again, it is apparent that the patentee was referring to
Zn-derived ash, and not to total SASH.
Metal detergents have been heretofore employed in
motor oils to assist in controlling varnish formation and
corrosion, and to thereby minimize the adverse impact which
varnish and corrosion have upon the efficiency of an
internal combustion engine by minimizing the clogging of
restricted openings and the reduction in the clearance of
moving parts.
U.S. Patent 4,089,791 relates to low ash mineral
lubricating oil compositions comprising a mineral oil base
in minor amounts of an overbased alkaline earth metal
compound, a zinc dihydrocarbyl dithiphosphate (ZDDP) and a
substituted trialkanolamine compound, wherein at least 50%
of the ZDDP compounds consists of zinc dialkaryl
dithiophosphates, in order to provide a formulated motor
1334667
-- 4 --
oil which will pass the MS IIC Rust Test and the L-38
Bearing Weight Loss Test. The patent illustrates three oil
formulations, containing overbased calcium detergent, ZDDP,
trialkanolamine and unspecified conventional lubricating
oil additives to provide viscosity index improvement,
antioxidant, dispersant and anti-foaming properties. The
illustrated formulations each had about 0.66 wt.% SASH
levels, based on the reported Ca and Zn concentrations. No
diesel motor oil formulations are illustrated.
U.S. Patent 4,153,562 relates to antioxidants,
which are disclosed to be particularly useful for
compounded lubricating oils that are intended for heavy
duty use in automotive crankcase formulations of relatively
low ash content, wherein the antioxidants are prepared by
the condensation of phosphorodithioates of alkylphenol
sulfides with unsaturated compounds such as styrene. The
antioxidants are exemplified at levels of from 0.3 to 1.25
wt.% in lube oil compositions (Example 3) which also
contain about 2.65 wt.% (a.i.) borated polyisobutenyl-
succinimide dispersant, about 0.06 wt.% Mg as overbased
magnesium sulfonate detergent inhibitor, and about 0.10
wt.% Zn as zinc dialkyldithiophosphate antiwear agent
(containing mixed C4/C5 alkyl groups).
U.S. Patent 4,157,972 indicates that the trend to
unleaded fuels and ashless lubricating compositions has
necessitated the search for non-metallic (ashless)
substitutes for metallo-organo detergents, and relates to
tetrahydropyrimidyl-substituted compounds which are
disclosed to be useful as ashless bases and rust
inhibitors. The Examples of the Patent compare the
performance of various lubricating oil formulations in a
Ford V8 varnish test (Table I) and additional formulations,
which are named as either "low-ash" or "ashless", in a
Humidity Cabinet Rust Test (Table II). The SASH levels of
the n low ash" formulations are not reported and cannot be
13~4~6~
determined from the information given for the metal
detergent- and ZDDP- components.
U.S. Patent 4,165,292 discloses that overbased
metal compounds provide effective rust inhibition in
automotive crankcase lubricants and that in the absence of
overbased additives, as in ashless oils, or when such
additives are present in reduced amounts, as in "low ash"
oils, rusting becomes a serious problem. Such rust
requirements are evaluated by ASTM Sequence IIC
engine-tests. The Patent discloses a non-ash forming
corrosion or rust inhibitor comprising a combination of an
oil-soluble basic organic nitrogen compound (having a
recited basicity value) and an alkenyl or alkyl substituted
succinic acid having from 12 to 50 carbon atoms. The basic
organic nitrogen compound and the carboxylic acid compound
are required to be used together to achieve the desired
rust-inhibiting properties. It is disclosed that best
results are achieved by use of an excess of amine over that
required to form the neutral salts of the substituted
succinic acid present.
U.S. Patent 4,502,970 relates to improved
crankcase lubricating oil compositions containing
lubricating oil dispersant, overbased metal detergent, zinc
dialkyldithiophosphate antiwear additive and
polyisobutenylsuccinic anhydride, in recited amounts.
Exemplary lubricating oil formulations are disclosed
containing 3 wt.% polyisobutenylsuccinimide dispersant,
polyisobutenylsuccinic anhydride, overbased metal sulfonate
or overbased sulfurized phenate detergents and zinc
dialkyldithiophosphate antiwear agents, in base oil, in
amounts of 3.0, 3.0, 2.0, 1.0 and 91.0 wt.%, respectively.
European Patent 24,146 relates to lubricating oil
compositions containing copper antioxidants, and
exemplifies copper antioxidants in lubricating oil
compositions also containing 1.0 wt. % of a 400 TBN
magnesium sulphonate (containing 9.2 wt. % magnesium), 0.3
13~4667
-- 6 --
wt. % of a 250 TBN calcium phenate (containing 9.3 wt. % of
calcium) and a zinc dialkyldithiophosphate in which the
alkyl groups or a mixture of such groups having between 4
and 5 carbon atoms and made by reacting phosphorous
P2S5 with a mixture of about 65% isobutyl alcohol and
35% of amyl alcohol, to give a phosphorous level of 1.0 wt.
% in lubricating oil composition.
Published British Patent Application 2,062,672
relates to additive compositions comprising sulfurized
alkyl phenol and an oil soluble carboxylic dispersant
containing a hydrocarbon base radical having a number
average molecular weight of at least 1300, which is
disclosed in combination with ash-producing detergents.
However, it is extremely difficult to translate
lube oil developments intended for passenger car and light
truck service, whether gasoline or light duty diesel
engines, into lubricating oils intended for use in heavy
duty diesel service.
R. D. Hercamp, SAE Technical Paper Series, Paper
No. 831720 (1983) reports development work on engine test
procedures to measure the relative ability of various
lubricant formulations to control oil consumption in heavy
duty diesel engines. The author indicates that lab
analysis of crown land deposits on the diesel engine
pistons show an organic binder to be present which contains
high molecular weight esters, and the author speculates
that oxidation products in the oil may be precursors for
the binder found in the deposits. It is indicated that
improved antioxidants could be the key to prevent premature
loss of oil consumption.
A. A. Schetelich, SAE Technical Paper Series,
Paper No. 831722 (1983) reports on the effect of
lubricating oil parameters on PC-l type heavy duty diesel
lubricating oil performance. It is noted that over the
past 30 years, the trend in heavy duty diesel oil industry
has been to decrease the sulfated ash levels from 2.5 wt.%
7 133~667
sulfated ash (SASH) in 1960 to the typical North American
SASH level of 0.8 to 1 wt.%, and to correspondingly
decrease the HD oils total base number (TBN) D28s6 values
from over 20 to the present typical North American TBN
values of from 7 to 10. Such reductions in SASH and TBN
levels are attributed by the author to be due to
improvement in performance of ashless components, including
ashless diesel detergents and ashless dispersants. In
diesel engine tests, no significant correlation was seen
between the level of either piston deposits or oil
consumption and the SASH or TBN levels, for about 1% to 2%
SASH levels and about 8 to 17% TBN levels. In contrast, a
significant correlation was seen between the level of
ashless component treat and the amount of piston deposits
(at the 92% confidence level) and oil consumption (at the
98% confidence level). It is noted by the authors that
this correlation is drawn with respect to diesel fuels
having average sulfur levels of less than about 0.5%. It
is indicated that the level of buildup of ash is
accelerated in the hotter engine areas. The author
concludes that at the 97% confidence level there should be
a correlation between oil consumption and piston deposits,
especially top land deposits, which are believed to
contribute to increased oil consumption due to two
phenomena: (1) these deposits decrease the amount of
blow-by flowing downwardly past the top land, which results
in a decreased gas loading behind the top ring of the
piston, which in turn leads to higher oil consumption; and
(2) increased bore polishing of the piston cylinder liner
by the top land deposits which in turn contributes to
higher oil consumption by migration of the oil into the
firing chamber of the cylinder along the polished bore
paths. Therefore, the Paper concluded that reduced ash in
the oil should be sought to reduce top land deposits, and
hence oil consumption.
This 1983 Schetelich paper reports formulation of
- 8_ 133~667
2 test oils, each containing about 1% SASH and having TBN levels of 10 and 9,
respectively, wherein each formulated oil contained overbased metal detergent
together with a zinc-source.
J.A. McGeehan, SAE Paper No. 831721, pp. 4.848-4.869 (1984) summarized
the results of a series of heavy duty diesel engine tests to investigate the effect of
top land deposits, fuel sulfur and lubricant viscosity on diesel engine oil
consumption and cylinder bore polishing. These authors also indicated that
excessive top land deposits cause high oil consumption and cylinder bore polishing,
although they added that cylinder board polishing is also caused in high sulfur fuels
by corrosion in oils of low ~lk~linity value. Therefore, they concluded that oil
should provide sufficient ~lk~linity to minimi7e the corrosive aspect of bore
polishing. The authors reported that an experimental 0.01% sulfated ash oil, which
was tested in a AVL-Mack TZ675* (turbocharged) 120-hour test in combination
with a 0.2% fuel sulfur, provided minimum top land deposits and very low oil
consumption, which was said to be due to the "very effective ashless inhibitor".
This latter component was not further defined. Further, from the data presented by
the author in Figure 4 of this Paper, there do not appear to be oil consumption
credits to reducing the ash level below 1%, since the oil consumption in the engine
actually rose upon reducing the SASH from 1 to 0.01%. This reinforces the
author's view that a low, but significant SASH level is required for sufficient
~,lk~linity to avoid oil consumption as a result of bore polishing derived from
corrosive aspects of the oil.
McGeehan concluded that the deposits on the top land correlate with oil
consumption but are not directly related to the lubricant sulfated ash, and
commented that these deposits can be controlled by the crankcase oil formulation.
* Trade Mark
,: ~
1334667
SUMMA~Y OF T~ INVENTION
In accordance with the present invention, there
are provided low sulfated ash, heavy duty diesel
lubricating oil compositions which comprise an oil of
lubricating viscosity as the major component and as the
minor component (A) at least about 3 wt.% of at least one
ashless dispersant, (B) at least 2 wt.% of at least one
sulfurized alkyl phenol, and (C) at least one metal
dihydrocarbyl dithiophosphate, wherein the lubricating oil
is characterized by a total sulfated ash (SASH) level of
less than about 0.6 wt% SASH and by a SASH:dispersant wt:wt
ratio of from about O.Ol to about 0.2:1.
It has been surprisingly found that the low ash
lubricating oils of this invention achieve greatly reduced
crownland deposits in heavy duty diesel engines while
maintaining the desired additional performance properties
for commercially acceptable oils. In particular, this
invention has been surprisingly found to provide low ash
formulations which pass the modern high severity heavy duty
diesel lubricating oil specification which went into effect
in April, 1987, namely, the American Petroleum Institute's
CE Specification. Therefore, the present invention
provides a method for preparing a heavy duty diesel
lubricating oil adapted for meeting the American Petroleum
Institute CE specifications which comprises controlling the
metal content of the oil to provide a total sulfated ash
(SASH) level in said oil of less than about 0.6 wt.% and a
SASH:dispersant weight:weight ratio of from 0.01:1 to about
0.2:1, and providing in said oil (A) at least about 3 wt.%
ashless dispersant, (B) at least about 2 wt.% sulfurized
alkyl phenol oxidation inhibitor, and (C) an antiwear
effective amount of at least one metal salt of a
dihydrocarbyl dithiophosphate wherein each of said
hydrocarbyl group in said acid has, on the average, at
least 6 carbon atoms.
- lo 1 3 34 6 67
The present invention further provides a method
for improving the performance of a heavy duty diesel
lubricating oil adapted for use in a diesel engine provided
with at least one tight top land piston, and preferably
further adapted for being powered by a normally liquid fuel
having a sulfur content of less than 1 wt.%, which
comprises controlling the metal content of the oil to
provide a total sulfated ash (SASH) level in said oil of
less than about 0.6 wt.% and a SASH:dispersant
weight:weight ratio of from 0.01:1 to about 0.2:1, and
providing in said oil (A) at least about 3 wt.% ashless
dispersant, (B) at least about 2 wt.% sulfurized alkyl
phenol oxidation inhibitor, and (C) an antiwear effective
amount of at least one metal salt of a dihydrocarbyl
dithiophosphate wherein each of said hydrocarbyl group in
said acid has, on the average, at least 6 carbon atoms.
BRIFF DESCRIPTION OF THE DRAWING
Figure 1 is a plot of oil consumption versus test
hours in a NTC-400 oil consumption test, as summarized in
Example 3.
1334~67
11
D~TAIT~n ~F~CRIPTION OF THE Ihv~ ON
Com~nent A
Ashless, nitrogen or ester containing dispersants
useful in this invention comprise boron-free members
selected from the group consisting of (i) oil soluble
salts, amides, imides, oxazolines and esters, or mixtures
thereof, of long chain hydrocarbon substituted mono and
dicarboxylic acids or their anhydrides; (ii) long chain
aliphatic hydrocarbon having a polyamine attached directly
thereto; and (iii) Mannich condensation products formed by
condensing about a molar proportion of long chain
hydrocarbon substituted phenol with about 1 to 2.5 moles of
formaldehyde and about 0.5 to 2 moles of polyalkylene
polyamine; wherein said long chain hydrocarbon group in
(i), (ii) and (iii) is a polymer of a C2 to C10, e.g.,
C2 to C5 monoolefin, said polymer having a number
average molecular weight of about 300 to about 5000.
Ari) The nitrogen- or ester- containing ashless
dispersants comprise at least one member selected from the
group consisting of oil soluble salts, amides, imides,
oxazolines and esters, or mixtures thereof, of long chain
hydrocarbon substituted mono and dicarboxylic acids or
their anhydrides wherein said long chain hydrocarbon group
is a polymer of a C2 to C10, e.g., C2 to C5,
monoolefin, said polymer having a number average molecular
weight of from about 700 to 5000.
The long chain hydrocarbyl substituted mono or
dicarboxylic acid material, i.e. acid, anhydride, or ester,
used in the dispersant includes long chain hydrocarbon,
generally a polyolefin, substituted with an average of from
- 12 - 133 ~ 6 67
about 0.8 to 2.0, preferably from about 1.0 to 1.6, e.g.,
1.1 to 1.3 moles, per mole of polyolefin, of an alpha or
beta- unsaturated C4 to C10 dicarboxylic acid, or
anhydride or ester thereof. Exemplary of such
dicarboxylic acids, anhydrides and esters thereof are
fumaric acid, itaconic acid, maleic acid, maleic anhydride,
chloromaleic acid, dimethyl fumarate, chloromaleic
anhydride, acrylic acid, methacrylic acid, crotonic acid,
cinnamic acid, etc.
Preferred olefin polymers for reaction with the
unsaturated dicarboxylic acids to form the dispersants are
polymers comprising a major molar amount of C2 to C10,
e.g. C2 to C5 monoolefin. Such olefins include
ethylene, propylene, butylene, isobutylene, pentene,
octene-l, styrene, etc. The polymers can be homopolymers
such as polyisobutylene, as well as copolymers of two or
more of such olefins such as copolymers of: ethylene and
propylene; butylene and isobutylene; propylene and
isobutylene; etc. Other copolymers include those in which
a minor molar amount of the copolymer monomers, e.g., 1 to
10 mole %, is a C4 to C18 non-conjugated diolefin,
e.g., a copolymer of isobutylene and butadiene: or a
copolymer of ethylene, propylene and 1,4-hexadiene; etc.
In some cases, the olefin polymer may be
completely saturated, for example an ethylene-propylene
copolymer made by a Ziegler-Natta synthesis using hydrogen
as a moderator to control molecular weight.
The olefin polymers used in the dispersants will
usually have number average molecular weights within the
range of about 700 and about 5,000, more usually between
about 800 and about 3000. Particularly useful olefin
polymers have number average molecular weights within the
range of about 900 and about 2500 with approximately one
terminal double bond per polymer chain. An especially
useful starting material for highly potent dispersant
additives is polyisobutylene. The number average molecular
1334667
- 13 -
weight for such polymers can be determined by several known
te~hn~ques. A convenient method for such determination is
by gel permeation chromatography (GPC) which additionally
provides molecular weight distribution information, see W.
W. Yau, J.J. Kirkland and D.D. Bly, "Modern Size
Exclusion Liquid Chromatography", John Wiley and Sons, New
York, 1979.
Processes for reacting the olefin polymer with the
C4_10 unsaturated dicarboxylic acid, anhydride or ester
are known in the art. For example, the olefin polymer and
the dicarboxylic acid material may be simply heated
together as disclosed in U.S. Patents 3,361,673 and
3,401,118 to cause a thermal "ene" reaction to take place.
Or, the olefin polymer can be first halogenated, for
example, chlorinated or brominated to about 1 to 8 wt. %,
preferably 3 to 7 wt. % chlorine, or bromine, based on the
weight of polymer, by passing the chlorine or bromine
through the polyolefin at a temperature of 60 to 250C,
e.g. 120 to 160C, for about 0.5 to 10, preferably 1 to 7
hours. The halogenated polymer may then be reacted with
sufficient unsaturated acid or anhydride at 100 to 250C,
usually about 180- to 235C, for about 0.5 to 10, e.g. 3 to
8 hours, so the product obtained will contain the desired
number of moles of the unsaturated acid per mole of the
halogenated polymer. Processes of this general type are
taught in U.S. Patents 3,087,436; 3,172,892; 3,272,746 and
others.
Alternatively, the olefin polymer, and the
unsaturated acid material are mixed and heated while adding
chlorine to the hot material. Processes of this type are
disclosed in U.S. Patents 3,215,707; 3,231,587; 3,912,764;
4,110,349; 4,234,435; and in U.K. 1,440,219.
By the use of halogen, about 65 to 95 wt. % of the
polyolefin, e.g. polyisobutylene will normally react with
the dicarboxylic acid material. Upon carrying out a
thermal reaction without the use of halogen or a catalyst,
1~3~667
then usually only about 50 to 75 wt. % of the poly-
isobutylene will react. Chlorination helps increase the
reactivity. For convenience, the aforesaid functionalitY
ratios of dicarboxylic acid producing units to polyolefin,
e.g., 0.8 to 2.0 , etc. are based upon the total amount of
polyolefin, that is, the total of both the reacted and
unreacted polyolefin, used to make the product.
The dicarboxylic acid producing materials can also
be further reacted with amines, alcohols, including
polyols, amino-alcohols, etc., to form other useful
dispersant additives. Thus, if the acid producing material
is to be further reacted, e.g., neutralized, then generally
a major proportion of at least 50 percent of the acid units
up to all the acid units will be reacted.
Amine compounds useful as nucleophilic reactants
for neutralization of the hydrocarbyl substituted
dicarboxylic acid materials include mono- and (preferably)
polyamines, most preferably polyalkylene polyamines, of
about 2 to 60, preferably 2 to 40 (e.g. 3 to 20), total
carbon atoms and about 1 to 12, preferably 3 to 12, and
most preferably 3 to 9 nitrogen atoms in the molecule.
These amines may be hydrocarbyl amines or may be
hydrocarbyl amines including other groups, e.g, hydroxy
groups, alkoxy groups, amide groups, nitriles, imidazoline
groups, and the like. Hydroxy amines with 1 to 6 hydroxy
groups, preferably 1 to 3 hydroxy groups are particularly
useful. Preferred amines are aliphatic saturated amines,
including those of the general formulas:
R-~-R', and R-IN-(CH2)s - IN-(CH2)s - N-R
R" R' R''' R'
(I) (II)
wherein R, R', R'' and R''' are independently selected from
the group consisting of hydrogen; Cl to C25 straight or
branched chain alkyl radicals; Cl to C12 alkoxy C2 to
- 15 - 133'~ ~ ~ 7
C6 alkylene radicals; C2 to Cl2 hydroxy amino
alkylene radicals; and Cl to Cl2 alkylamino C2 to
C6 alkylene radicals; and wherein R"' can additionally
comprise a moiety of the formula:
(CH2)s, rJ II (III)
~ _t'
wherein R' is as defined above, and wherein s and s' can be
the same or a different number of from 2 to 6, preferably 2
to 4; and t and t' can be the same or different and are
numbers of from O to lO, preferably 2 to 7, and most
preferably about 3 to 7, with the proviso that the sum of t
and t' is not greater than 15. To assure a facile
reaction, it is preferred that R, R', R'', R''', s, s', t
and t' be selected in a manner sufficient to provide the
compounds of Formulas I and II with typically at least one
primary or secondary amine group, preferably at least two
primary or secondary amine groups. This can be achieved by
selecting at least one of said R, R', R" or R''' groups to
be hydrogen or by letting t in Formula IV be at least one
when R"' is H or when the III moiety possesses a secondary
amino group. The most preferred amine of the above
formulas are represented by Formula II and contain at least
two primary amine groups and at least one, and preferably
at least three, secondary amine groups.
Non-limiting examples of suitable amine compounds
include: l,2-diaminoethane; l,3-diaminopropane;
l,4-diaminobutane; l,6-diaminohexane; polyethylene amines
such as diethylene triamine; triethylene tetramine;
tetraethylene pentamine; polypropylene amines such as
l,2-propylene diamine; di-(l,2-propylene)triamine;
di-(l,3-propylene) triamine; N,N-dimethyl-l,3-diamino-
propane; N,N-di-(2-aminoethyl) ethylene diamine;
N,N-di(2-hydroxyethyl)-l,3-propylene diamine; 3-dodecyloxy-
propylamine; N-dodecyl-l,3-propane diamine; tris hydroxy-
methylaminomethane (THAM); diisopropanol amine; diethanol
- 16 - 13~ 46 67
amine; triethanol amine; mono-, di-, and tri-tallow amines;
amino morpholines such as N-(3-aminopropyl)morpholine; and
mixtures thereof.
Other useful amine compounds include: alicyclic
diamines such as 1,4-di(aminomethyl) cyclohexane, and
heterocyclic nitrogen compounds such as imidazolines, and
N-aminoalkyl piperazines of the general formula (IV):
,
~ CH2-CH2~
H-NH-(CH2)p N ~ N (CH2)--NH H
- ~ CH2-CH2 _ n2 ~ P2 - n3
wherein Pl and P2 are the same or different and are
each integers of from 1 to 4, and n1, n2 and n3 are
the same or different and are each integers of from 1 to
3. Non-limiting examples of such amines include
2-pentadecyl imidazoline; N-(2-aminoethyl) piperazine; etc.
Commercial mixtures of amine compounds may
advantageously be used. For example, one process for
preparing alkylene amines involves the reaction of an
alkylene dihalide (such as ethylene dichloride or propylene
dichloride) with ammonia, which results in a complex
mixture of alkylene amines wherein pairs of nitrogens are
joined by alkylene groups, forming such compounds as
diethylene triamine, triethylenetetramine, tetraethylene
pentamine and isomeric piperazines. Low cost
poly(ethyleneamines) compounds averaging about 5 to 7
nitrogen atoms per molecule are available commercially
under trade names such as "Polyamine H", "Polyamine 400",
"Dow Polyamine E-100", etc.
Useful amines also include polyoxyalkylene
polyamines such as those of the formulae:
NH2- alkylene t O-alkylene ~ NH2 (V)
m
where m has a value of about 3 to 70 and preferably 10 to
3s; and
- 17 ~ 4667
R ~ alkylen~ 4 -alkYlene t NH2)
n a (VI)
where "n" has a value of about 1 to 40 with the provision
that the sum of all the n's is from about 3 to about 70 and
preferably from about 6 to about 35, and R is a polyvalent
saturated hydrocarbon radical of up to ten carbon atoms
wherein the number of substituents on the R group is
represented by the value of "a", which is a number of from
3 to 6. The alkylene groups in either formula (V) or (VI)
may be straight or branched chains containing about 2 to 7,
and preferably about 2 to 4 carbon atoms.
The polyoxyalkylene polyamines of formulas (V) or
(VI) above, preferably polyoxyalkylene diamines and
polyoxyalkylene triamines, may have average molecular
weights ranging from about 200 to about 4000 and preferably
from about 400 to about 2000. The preferred polyoxyal-
kylene polyoxyalkylene polyamines include the
polyoxyethylene and polyoxypropylene diamines and the
polyoxypropylene triamines having average molecular weights
ranging from about 200 to 2000. The polyoxyalkylene
polyamines are commercially available and may be obtained,
for example, from the Jefferson Chemical Company, Inc.
under the trade mark "Jeffamines D-230, D-400, D-1000,
D-2000, T-403", etc.
The amine is readily reacted with the selected
dicarboxylic acid material, e.g. alkenyl succinic
anhydride, by heating an oil solution containing 5 to 95
wt. % of dicarboxylic acid material to about 100 to
2SO-C., preferably 125 to 175-C., generally for 1 to 10,
e.g. 2 to 6 hours until the desired amount of water is
removed. The heating is preferably carried out to favor
formation of imides or mixtures of imides and amides,
rather than amides and salts. Reaction ratios of
dicarboxylic material to equivalents of amine as well as
- 18 - 1334667
the other nucleophili~ reactants described herein can vary
considerably, depending on the reactants and type of bonds
formed. Generally from 0.1 to 1.0, preferably from about
0.2 to 0.6, e.g., 0.4 to 0.6, moles of dicarboxylic acid
moiety content (e.g., grafted maleic anhydride content) is
used per equivalent of nucleophilic reactant, e.g., amine.
For example, about 0.8 mole of a pentaamine (having two
primary amino groups and five equivalents of nitrogen per
molecule) is preferably used to convert into a mixture of
amides and imides, the product formed by reacting one mole
of olefin with sufficient maleic anhydride to add 1.6 moles
of succinic anhydride groups per mole of olefin, i.e.,
preferably the pentaamine is used in an amount sufficient
to provide about 0.4 mole (that is, 1.6 divided by (0.8 x
5) mole) of succinic anhydride moiety per nitrogen
equivalent of the amine.
The nitrogen containing dispersants can be further
treated by boration as generally taught in U.S. Patent
Nos. -3,087,936 and 3,254,025. This is readily
accomplished by ! - -
~treating the selected acyl nitrogen dispersant with a boron
compound selected from the class consisting of boron oxide,
boron halides, boron acids and esters of boron acids in an
amount to provide from about 0.1 atomic proportion of boron
for each mole of said acylated nitrogen composition to
about 20 atomic proportions of boron for each atomic
proportion of nitrogen of said acylated nitrogen
composition. Usefully the dispersants of the inventive
combination contain from about 0.05 to 2.0 wt. %, e.g. 0.05
to 0.7 wt. % boron based on the total weight of said
borated acyl nitrogen compound. The boron, which appears
to be in the product as dehydrated boric acid polymers
(primarily (HBo2)3), is believed to attach to the
dispersant imides and diimides as amine salts, e.g., the
metaborate salt of said diimide.
13346~
- 19 -
Treating is readily carried out by adding from
about 0.05 to 4, e.g. 1 to 3 wt. ~ (based on the weight of
said acyl nitrogen compound) of said boron compound,
preferably boric acid which is most usually added as a
slurry to said acyl nitrogen compound and heating with
stirring at from about 135-C. to 190, e.g. 140-170C., for
from 1 to 5 hours followed by nitrogen stripping at said
temperature ranges. Or, the boron treatment can be carried
out by adding boric acid to the hot reaction mixture of the
dicarboxylic acid material and amine while removing water.
The tris(hydroxymethyl) amino methane (THAM) can
be reacted with the aforesaid acid material to form amides,
imides or ester type additives as taught by U.K. 984,409,
or to form oxazoline compounds and borated oxazoline
compounds as described, for example, in U.S. 4,102,798;
4,116,876 and 4,113,639.
The ashless dispersants may also be esters derived
from the aforesaid long chain hydrocarbon substituted
dicarboxylic acid material and from hydroxy compounds such
as monohydric and polyhydric alcohols or aromatic compounds
such as phenols and naphthols, etc. The polyhydric
alcohols are the most preferred hydroxy compound and
preferably contain from 2 to about 10 hydroxy radicals, for
example, ethylene glycol, diethylene glycol, triethylene
glycol, tetraethylene glycol, dipropylene glycol, and other
alkylene glycols in which the alkylene radical contains
from 2 to about 8 carbon atoms. Other useful polyhydric
alcohols include glycerol, mono-oleate of glycerol,
monostearate of glycerol, monomethyl ether of glycerol,
pentaerythritol, dipentaerythritol, and mixtures thereof.
The ester dispersant may also be derived from
unsaturated alcohols such as allyl alcohol, cinnamyl
alcohol, propargyl alcohol, 1-cyclohexane-3-ol, and oleyl
alcohol. Still other classes of the alcohols capable of
yielding the esters of this invention comprise the
ether-alcohols and amino-alcohols including, for example,
13~4667
- 20 -
the oxy-alkylene, oxy-arylene-, amino-alkylene-, and
amino-arylene-substituted alcohols having one or more
oxy-alkylene, amino-alkylene or amino-arylene oxy-arylene
radicals. They are exemplified by Cellosolve, Carbitol,
N,N,N',N'-tetrahydroxy-trimethylene di-amine, and
ether-alcohols having up to about 150 oxy-alkylene radicals
in which the alkylene radical contains from 1 to about 8
carbon atoms.
The ester dispersant may be di-esters of succinic
acids or acidic esters, i.e., partially esterified succinic
acids; as well as partially esterified polyhydric alcohols
or phenols, i.e., esters having free alcohols or phenolic
hydroxyl radicals. Mixtures of the above illustrated
esters likewise are contemplated within the scope of this
invention.
The ester dispersant may be prepared by one of
several known methods as illustrated for example in U.S.
Patent 3,381,022. The ester dispersants may also be
borated, similar to the nitrogen containing dispersants, as
described above.
Hydroxyamines which can be reacted with the
aforesaid long chain hydrocarbon substituted dicarboxylic
acid materials to form dispersants include 2-amino-1-bu-
tanol, 2-amino-2-methyl-1-propanol, p-(beta-hydroxy-
ethyl)-aniline, 2-amino-1-propanol, 3-amino-1-propanol,
2-amino-2-methyl-1, 3-propane-diol, 2-amino-2-ethyl-1,
3-propanediol, N-(beta-hydroxy-propyl)-N'-(beta-amino-
ethyl)-piperazine, tris(hydroxymethyl) amino-methane (also
known as trismethylolaminomethane), 2-amino-1-butanol,
ethanolamine, beta-(beta-hydroxyethoxy)ethylamine, and the
like. Mixtures of these or similar amines can also be
employed. The above description of nucleophilic reactants
suitable for reaction with the hydrocarbyl substituted
dicarboxylic acid or anhydride includes amines, alcohols,
and compounds of mixed amine and hydroxy containing
reactive functional groups, i.e., amino-alcohols.
1334667
- 21 -
A preferred group of ashless dispersants are those
derived from polyisobutylene substituted with succinic
anhydride groups and reacted with polyethylene amines,
e.g. tetraethylene pentamine, pentaethylene hexamine,
polyoxyethylene and polyoxypropylene amines, e.g.
polyoxypropylene diamine, trismethylolaminomethane and
pentaerythritol, and combinations thereof. One
particularly preferred dispersant combination involves a
combination of (i) polyisobutene substituted with succinic
anhydride groups and reacted with (ii) a hydroxy compound,
e.g. pentaerythritol, (iii) a polyoxyalkylene polyamine,
e.g. polyoxypropylene diamine, and (iv) a polyalkylene
polyamine, e.g. polyethylene diamine and tetraethylene
pentamine using about 0.3 to about 2 moles each of (ii) and
(iv) and about 0.3 to about 2 moles of (iii) per mole of
(i) as described in U.S. Patent 3,804,763. Another
preferred dispersant combination involves the combination
of (i) polyisobutenyl succinic anhydride with (ii) a
polyalkylene polyamine, e.g. tetraethylene pentamine, and
(iii) a polyhydric alcohol or polyhydroxy-substituted
aliphatic primary amine, e.g. pentaerythritol or
trismethylolaminomethane as described in U.S. Patent
3,632,511.
A(ii~ Also useful as ashless nitrogen-containing
dispersant in this invention are dispersants wherein a
nitrogen containing polyamine is attached directly to the
long chain aliphatic hydrocarbon as shown in U.S. Patents
3,275,554 and 3,565,804 where the halogen group on the
halogenated hydrocarbon is displaced with various alkylene
polyamines.
A(iii) Another class of nitrogen containing
dispersants which may be used are those containing Mannich
base or Mannich condensation products as they are known in
the art. Such Mannich condensation products generally are
prepared by condensing about 1 mole of a high molecular
weight hydrocarbyl substituted mono-or polyhydroxy benzene
- 22 - 1334~67
(Q . g., having a number average molecular weight of l,ooo or
greater) with about 1 to 2.5 moles of formaldehyde or
paraformaldehyde and about o.S to 2 moles polyalkylene
polyamine as disclosed, e.g., in U.S. Patents 3,442,808;
3,649,229 and 3,798,165. Such ~
..__ . , . , .. . . . . . , , . . , ,, . , . , , ,~
Mannich condensation products may include a long chain,
high molecular weight hydrocarbon on the phenol group or
may be reacted with a compound containing such a
hydrocarbon, e.g., polyalkenyl succinic anhydride as shown
in said aforementioned U.S. Patent 3,442,808.
Component B
Component B of the compositions of this invention
is at least one sulfurized alkyl phenol as oxidation
inhibitor. Sulfurized alkyl phenols and the methods of
preparing them are known in the art and are disclosed, for
example, in the following U.S. Pa~ents 2,139,766,
2,198,828;~- ----------------~ -- - --i
2,230,542; 2,836,565; 3,285,854; 3,538,166; 3,844,956; and
3,951,830.
In general, the sulfurized alkyl phenol may be
prepared by reacting an alkyl phenol with a sulfurizing
agent such as elemental sulfur, a sulfur halide (e.g.,
sulfur monochloride or sulfur dichloride), a mixture of
hydrogen sulfide and sulfur dioxide, or the like. The
preferred sulfurizing agents are sulfur and the sulfur
halides, and especially the sulfur chlorides, with sulfur
dichloride (SC12) being especially preferred.
The alkyl phenols which are sulfurized to produce
Component B are generally compounds containing at least one
hydroxy group (e.g., from 1 to 3 hydroxy groups) and at
least one alkyl radical (e.g., from 1 to 3 alkyl radicals)
attached to the same aromatic ring. The alkyl radical
ordinarily contains about 3-lO0 and preferably about 6-20
carbon atoms. The alkyl phenol may contain more than one
hydroxy group as exemplified by alkyl resorcinols,
- 23 - 13 3 ~ 6 6 7
hydroquinones and catechols, or it may contain more than
one alkyl radical: but normally it contains only one of
each. Compounds in which the alkyl and hydroxy groups are
ortho, meta and para to each other, and mixtures of such
compound~, are within the scope of the invention.
Illustrative alkyl phenols are n-propylphenol,
isopropylphenol, n-butylphenol, t-butylphenol, hexylphenol,
heptylphenol, octylphenol, nonylphenol, n-dodecylphenol,
(propene tetramer)-substituted phenol, octadecylphenol,
elcosylphenol, polybutene (molecular weight about
1000)-substituted phenol, n-dodecylresorcinol and
2,4-di-t-butylphenol. Also included are methylene-bridged
alkyl phenol~ of the type which may be prepared by the
reaction of an alkyl phenol with formaldehyde or a
formaldehyde-yielding reagent such as trioxane or
paraformaldehyde.
The sulfurized alkyl phenol is typically prepared
by reacting the alkyl phenol with the sulfurizing agent at
a temperature within the range of about 100-250-C. The
reaction may take place in a substantially inert diluent
such as toluene, xylene, petroleum naphtha, mineral oil,
Cellosolve or the like. If the sulfurizing agent is a
sulfur halide, and especially if no diluent is used, it is
frequently preferred to remove acidic materials such as
hydrogen halides by vacuum stripping the reaction mixture
or blowing it with an inert gas such as nitrogen. If the
sulfurizing agent is sulfur, it is frequently advantageous
to blow the sulfurized product with an inert gas such as
nitrogen or air so as to remove sulfur oxides and the like.
Component C
Component C of the compositions of this invention
is an anti-wear agent comprising at least one metal salt of
at least one dihydrocarbyl dithiophosphoric acid wherein
the hydrocarbyl groups contain an average of at least 6
carbon atoms.
The acids from whiCh the metal salts can be
133 t667
- 24 -
derived can be illustrated by acids of the formula
R1O - P - s - H
R2 _ I
wherein Rl and R2 are the same or different and are
alkyl, cycloalkyl, aralkyl, alkaryl or substituted
substantially hydrocarbon radical derivatives of any of the
above groups, and wherein the Rl and R2 groups in the
acid each have, on average, at least 6 carbon atoms.
By "substantially hydrocarbon~ ig meant radicals
containing substituent groups (e.g., 1 to 4 substituent
groups per radical moiety) such as ether, ester, nitro or
halogen which do not materially affect the hydrocarbOn
character of the radical.
Specific examples of suitable R1 and R2
radicals include isopropyl, isobutyl, n-butyl, sec-butyl,
n-hexyl, heptyl, 2-ethylhexyl, diisobutyl, isooctyl, decyl,
dodecyl, tetradecyl, hexadecyl, octadecyl, butylphenyl,
o,p-depentylphenyl, octylphenyl, polyisobutene-(molecular
weight 350)-substituted phenyl, tetrapropylene-substituted
phenyl, beta-octylbutylnaphthyl, cyclopentyl, cyclohexyl,
phenyl, chlorophenyl, o-dichlorophenyl, bromophenyl,
naphthenyl, 2-methylcyclohexyl, benzyl, chlorobenzyl,
chloropentyl, dichlorophenyl, nitrophenyl, dichlorodecyl
and xenyl radicals. Alkyl radicals having about 6-30
carbon atoms, and aryl radicals having about 6-30 carbon
atoms, are preferred. Particularly preferred Rl and R2
radicals are alkyl of 6 to 18 carbons.
The phosphorodithioic acids are readily obtainable
by the reaction of phosphorus pentasulfide and an alcohol
or phenol. The reaction involves mixing, at a temperature
of about 20-200-C, 4 moles of the alcohol or phenol with
one mole of phosphorus pentasulfide. Hydrogen sulfide is
liberated as the reaction takes place.
The metal salts which are useful in this invention
include those salts containing Group I metals, Group II
metals, aluminum, lead, tin, molybdenum, manganese, cobalt
- 2S - 13346 67
and nickel. Zinc is the preferred metal. Examples of metal
compounds which may be reacted with the acid include
lithium oxide, lithium hydroxide, lithium carbonate,
lithium pentylate, sodium oxide, sodium hydroxide, sodium
carbonate, sodium methylate, sodium propylate, sodium
phenoxide, potassium oxide, potassium hydroxide, potassium
carbonate, potassium methylate, silver oxide, silver
carbonate, magnesium oxide, magnesium hydroxide, magnesium
carbonate, magnesium ethylate, magnesium propylate,
magnesium phenoxide, calcium oxide, calcium hydroxide,
calcium carbonate, calcium methylate, calcium propylate,
calcium pentylate, zinc oxide, zinc hydroxide, zinc
carbonate, zinc propylate, strontium oxide, strontium
hydroxide, cadmium oxide, cadmium hydroxide, cadmium
carbonate, cadmium ethylate, barium oxide, barium
hydroxide, barium hydrate, barium carbonate, barium
ethylate, barium pentylate, aluminum oxide, aluminum
propylate, lead oxide, lead hydroxide, lead carbonate, tin
oxide, tin butylate, cobalt oxide, cobalt hydroxide, cobalt
carbonate, cobalt pentylate, nickel oxide, nickel hydroxide
and nickel carbonate.
In some instances, the incorporation of certain
ingredients, particularly carboxyl ic acids or metal
carboxylates such as small amounts of the metal acetate or
acetic acid used in conjunction with the metal reactant
will facilitate the reaction and result in an improved
product. For example, the use of up to about 596 of zinc
acetate in combination with the required amount of zinc
oxide facilitates the formation of a zinc
phosphorodithioate .
The preparation of metal phosphorodithioates is
well known in the art and is described in a large number of
issued patents, including U.S. Patents 3, 293 ,181;
3,397,145; 3,396,109; and 3,442,804.
- 26 - 1 3 34 6 6 7
T~T~ICATING COMPOSITIONS
Lubricating oil compositions, e . automatic
transmission fluids, heavy duty oils suitable for diesel
engine~ (that i~, compression ignition engines)~ etc., can
be prepared with the additives of the invention. Universal
type crankcase oils wherein the same lubricating oil
compo itions can be used for both gasoline and diesel
engin- c~n al80 be prepared. These lubricating oil
formulations conventionally contain several different types
of additives that will supply the characteristics that are
required in the formulations. Among these types of
additives are included viscosity index improvers,
antioxidants, corrosion inhibitors, detergents, pour point
depressants, other antiwear agents, etc., provided the
fully formulated oil satisfies the low total SASH
requirements of this invention.
In the preparation of heavy duty diesel
lubricating oil formulations it is common practice to
introduce the additives in the form of 10 to 80 wt. %, e.g.
20 to 80 wt. % active ingredient concentrates in
hydrocarbon oil, e.g. mineral lubricating oil, or other
suitable solvent. Usually these concentrates may be diluted
with 3 to 100, e.g. 5 to 40 parts by weight of lubricating
oil, per part by weight of the additive package, in forming
finished lubricants, e.g. crankcase motor oils. The
purpose of concentrates, of course, is to make the handling
of the various materials less difficult and awkward as well
as to facilitate solution or di~persion in the final
blend. Thus, a Component A ashless dispersant would be
usually employed in the form of a 40 to s0 wt. %
concentrate, for example, in a lubricating oil fraction.
Components A, B and C of the present invention
will be generally used in admixture with a lube oil
basestock, comprising an oil of lubricating viscosity,
including natural and synthetic lubricating oils and
mixtures thereof.
- 27 - 1 3~ 6 67
Components A, B and C can be inCorporated into a
lubricating oil in any convenient way. Thu~, these
mixtures can be added directly to the oil by dispersing or
dis~olving the same in the oil at the desired level of
concentrations of the detergent inhibitor and antiwear
agent, respectively. Such blending into the additional
lube oil can occur at room temperature or elevated
temperatures. Alternatively, the Components A, B and C can
be blended with a suitable oil-soluble solvent and base oil
to form a concentrate, and then blending the concentrate
with a lubricating oil basestock to obtain the final
formulation, i.e., the fully formulated lubricating oil
composition. Such concentrates will typicall-y contain (on
an active ingredient (A.I.) basis) from about 10 to about
40 wt. %, and preferably from about 20 to about 35 wt. %,
Component A ashless dispersant additive, typically from
about 10 to 40 wt. %, preferably from about 15 to 25 wt. %
Component B antioxidant additive, typically from about 5 to
15 wt.%, and preferably from about 7 to 12 wt.%, Component
C antiwear additive, and typically from about 30 to 80 wt.
%, preferably from about 40 to 60 wt. %, base oil, based on
the concentrate weight.
The fully formulated lubricating oil compositions
of this invention are also characterized (1) by a total
sulfate ash value (SASH) concentration of from 0.01 to
about 0.6 wt.% SASH, preferably from about 0.1 to about 0.5
wt.% SASH, and more preferably from about 0.2 to about 0.45
wt.% SASH: and (2) by a wt.~ SASH to wt.% Component A ratio
of from about 0.01:1 to about 0.2:1, preferably from about
0.02:1 to 0.15:1, and more preferably from about 0.03 to
0.1 wt.%. By "total sulfated ash" herein is meant the
total weight % of ash which is determined for a given oil
(based on the oil's metallic component~) by ASTM D874.
The lubricating oil basestock for Components A, B
and C typically is adapted to perform a selected function
- 28 - 133 ~g 6~
by the incorporation of additional additives therein to
form lubricating oil compositions (i.e., formulations).
Natural oilg include animal oils and vegetable
oils (e.g., castor, lard oil) liquid petroleum oils and
hydrorefined, solvent-treated or acid-treated mineral
lubricating oils of the paraffinic, naphthenic and mixed
paraffinic-naphthenic types. Oils of lubricating viscosity
derived from coal or shale are also useful base oils.
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
oil~. These are exemplified by polyoxyalkylene polymers
prepared by polymerization of ethylene oxide or propylene
oxide, the alkyl and aryl ethers of these polyoxyalkylene
polymers (e.g., methyl-poly isopropylene glycol ether
having an average molecular weight of 1000, diphenyl ether
of poly-ethylene glycol having a molecular weight of
500-1000, diethyl ether of polypropylene glycol having a
molecular weight of 1000-1500); and mono- and
polycarboxylic esters thereof, for example, the acetic acid
esters, mixed C3-C8 fatty acid esters and C13 Oxo
acid diester of tetraethylene glycol.
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). Specific examples of these esters
include dibutyl adipate, di(2-ethylhexyl)sebacate,
di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate,
- 29 - 133~6~7
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.
Esters useful as synthetic oils also include those
made from C5 to C12 monocarboxylic acids and polyols
and polyol ethers such as neopentyl glycol, trimethyl-
olpropane, pentaerythritol, dipentaerythritol and
tripentaerythritol.
Silicon-based oils such as the polyalkyl-,
polyaryl-, polyalkoxy-, or polyaryloxysiloxane oils and
silicate oils comprise another useful class of synthetic
lubricants; they include tetraethyl silicate,
tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate,
tetra-(4-methyl-2-ethylhexyl) silicate, tetra-(p-tert-
butylphenyl) silicate, hexa-(4-methyl-2-pentoxy)
disiloxane, poly(methyl) siloxanes and poly(methylphenyl)
siloxanes. Other synthetic lubricating oils include liquid
esters of phosphorus-containing acids (e.g., tricresyl
phosphate, trioctyl phosphate, diethyl ester of
decylphosphonic acid) and polymeric tetrahydrofurans.
Unrefined, refined and rerefined oils can be used
in the lubricants of the present invention. Unrefined oils
are those obtained 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
distillation or ester oil obtained directly from an
esterification process and used without further treatment
would be an unrefined oil. Refined oils 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, such as
distillation, solvent extraction, acid or base extraction,
1334~67
filtration and percolation are known to those skilled in
the art. Rerefined oils are obtained by processes similar
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 for
removal of spent additives and oil breakdown products.
The novel compositions of the present invention
can be used with V.I improvers to form multi-grade diesel
engine lubricating oils. Viscosity modifiers impart high
and low temperature operability to the lubricating oil and
permit it to remain relatively viscous at elevated
temperatures and also exhibit acceptable viscosity or
fluidity at low temperatures. Viscosity modifiers are
generally high molecular weight hydrocarbon polymers
including polyesters. The viscosity modifiers may also be
derivatized to include other properties or functions, such
as the addition of dispersancy properties. These oil
soluble viscosity modifying polymers will generally have
number average molecular weights of from 103 to 106,
preferably 104 to 106, e.g., 20,000 to 250,000, as
determined by gel permeation chromatography or osmometry.
Examples of suitable hydrocarbon polymers include
homopolymers and copolymers of two or more monomers of C2
to C30, e.g. C2 to C8 olefins, including both alpha
olefins and internal olefins, which may be straight or
branched, aliphatic, aromatic, alkyl-aromatic,
cycloaliphatic, etc. Frequently they will be of ethylene
with C3 to C30 olefins, particularly preferred being
the copolymers of ethylene and propylene. Other polymers
can be used such as polyisobutylenes, homopolymers and
copolymers of C6 and higher alpha olefins, atactic
polypropylene, hydrogenated polymers and copolymers and
terpolymers of styrene, e.g. with isoprene and/or butadiene
- 31 - 13~4667
and hydrogenated derivatiVeS thereof. The polymer may be
degraded in molecular weight, for example by mastication,
extrusion, oxidation or thermal degradation, and it may be
oxidized and contain oxygen. Also included are derivatized
polymers such as post-grafted interpolymers of
ethylene-propylene with an active monomer such as maleic
anhydride which may be further reacted with an alcohol, or
amine, e.g. an alkylene polyamine or hydroxy amine, e.g.
see U.S. Patent Nos. 4,089,794; 4,160,739; 4,137,18S; or
copolymers of ethylene and propylene reacted or grafted
with nitrogen compounds such as shown in U.S. Patent Nos.
4,068,056; 4,068,058; 4,146,489 and 4,149,984.
The preferred hydrocarbon polymers are ethylene
copolymers containing from lS to 90 wt. % ethylene,
preferably 30 to 80 wt. % of ethylene and 10 to 8S wt. %,
preferably 20 to 70 wt. % of one or more C3 to C28,
preferably C3 to C18, more preferably C3 to C8,
alpha-olefins. While not essential, such copolymers
preferably have a degree of crystallinity of less than 2S
wt. %, as determined by X-ray and differential scanning
calorimetry. Copolymers of ethylene and propylene are most
preferred. Other alpha-olefins suitable in place of
propylene to form the copolymer, or to be used in combin-
ation with ethylene and propylene, to form a terpolymer,
tetrapolymer, etc. , include l-butene, l-pentene, 1-hexene,
l-heptene, 1-octene, l-nonene, l-decene, etc.; also
branched chain alpha-olefins, such as 4-methyl-1-pentene,
4-methyl-1-hexene, S-methylpentene-l, 4,4-di-
methyl-l-pentene, and 6-methylheptene-1, etc., and mixtures
thereof.
Terpolymers, tetrapolymers, etc., of ethylene,
said C3-C28 alpha-olefin, and a non-conjugated diolefin
or mixtures of such diolefins may also be used. The amount
of the non-conjugated diolefin generally ranges from about
O.S to 20 mole percent, preferably from about 1 to about 7
mole percent, based on the total amount of ethylene and
alpha-olefin present.
- 32 - 1 3 ~ ~ 6 6 7
The polyester V.I. improvers are generally
polymers of esters of ethylenically unsaturated C3 to
C8 mono- and dicarboxylic acids such as methacrylic and
acrylic acids, maleic acid, maleic anhydride, fumaric acid,
etc.
Examples of unsaturated esters that may be used
include those of aliphatic saturated mono alcohols of at
least 1 carbon atom and preferably of from 12 to 20 carbon
atoms, such as decyl acrylate, lauryl acrylate, stearyl
acrylate, eicosanyl acrylate, docosanyl acrylate, decyl
methacrylate, diamyl fumarate, lauryl methacrylate, cetyl
methacrylate, stearyl methacrylate, and the like and
mixtures thereof.
Other esters include the vinyl alcohol esters of
C2 to C22 fatty or mono carboxylic acids, preferably
saturated such as vinyl acetate, vinyl laurate, vinyl
palmitate, vinyl stearate, vinyl oleate, and the like and
mixtures thereof. Copolymers of vinyl alcohol esters with
unsaturated acid esters such as the copolymer of vinyl
acetate with dialkyl fumarates, can also be used.
The esters may be copolymerized with still other
unsaturated monomers such as olefins, e.g. 0.2 to 5 moles
f C2 ~ C20 aliphatic or aromatic olefin per mole of
unsaturated ester, or per mole of unsaturated acid or
anhydride followed by esterification. For example,
copolymers of styrene with maleic anhydride esterified with
alcohols and amines are known, e.g., see U.S. Patent
3,702,300.
Such ester polymers may be grafted with, or the
ester copolymerized with, polymerizable unsaturated
nitrogen-containing monomers to impart dispersancy to the
V.I. improvers. Examples of suitable unsaturated
nitrogen-containing monomers include those containing 4 to
20 carbon atoms such as amino substituted olefins as
p-(beta-diethylaminoethyl)styrene; basic nitrogen-con-
taining heterocycles carrying a polymerizable ethylenically
3~6~7
- 33 -
unsaturated substituent~ e-g- the vinyl pyridines and the
vinyl alkyl pyridineS such as 2-vinyl-5-ethyl pyridine,
2-methyl-5-vinyl pyridine, 2-vinyl-pyridine, 4-vinyl-
pyridine, 3-vinyl-pyridine~ 3-methyl-5-vinyl-pyridine~
4-methyl-2-vinyl-pyridine, 4-ethyl-2-vinyl-pyridine and
2-butyl-1-5-vinyl-pyridine and the like.
N-vinyl lactams are also suitable, e.g. N-vinyl
pyrrolidones or N-vinyl piperidones.
The vinyl pyrrolidones are preferred and are
exemplified by N-vinyl pyrrolidone, N-(l-methylvinyl)
pyrrolidone, N-vinyl-5-methyl pyrrolidone, N-vinyl-3,
3-dimethylpyrrolidone, N-vinyl-5-ethyl pyrrolidone, etc.
Metal detergent inhibitors are generally basic
(viz, overbased) alkali or alkaline earth metal salts (or
mixtures thereof, e.g. mixtures of Ca and Mg salts) of one
or more organic sulfonic acid (generally a petroleum
sulfonic acid or a synthetically prepared alkaryl sulfonic
acid), petroleum naphthenic acids, alkyl benzene sulfonic
acids, alkyl phenols, alkylene-bis-phenols, oil soluble
fatty acids and the like, such as are described in U.S.
Patent Nos. 2,501,731: 2,616,904; 2,616,905; 2,616,906;
2,616,911; 2,616,924; 2,616,925; 2,617,049; 2,777,874;
3,027,325; 3,256,186; 3,282,835; 3,384,585; 3,373,108;
3,365,396; 3,342,733; 3,320,162; 3,312,618; 3,318,809; and
3,562,159. Among the petroleum sulfonates,
the most useful products are those prepared by the
sulfonation of suitable petroleum fractions with subsequent
removal of acid sludge and purification. Synthetic alkaryl
sulfonic acids are usually prepared from alkylated benzenes
such as the Friedel-Crafts reaction product of benzene and
a polymer such as tetrapropylene, C18-C24 hydrocarbon
polymer, etc. Suitable acids may also be obtained by
sulfonation of alkylated derivatives of such compounds as
diphenylene oxide thianthrene, phenolthioxine,
~ 34 ~ 13 ~ ~ 6 67
diphenylene sulfide, phenothiazine, diphenyl oxide,
diphenyl sulfide, diphenylamine, cyclohexane, decahydro
naphthalene and the like.
Highly basic alkali and alkaline earth metal
sulfonates are frequently used as detergents. They are
usually produced by heating a mixture comprising an
oil-soluble sulfonate or alkaryl sulfonic acid, with an
excess of alkali and/or alkaline earth metal compound above
that required for complete neutralization of any sulfonic
acid present and thereafter forming a dispersed carbonate
complex by reacting the excess metal with carbon dioxide to
provide the desired overbasing. The sulfonic acids are
typically obtained by the sulfonation of alkyl substituted
aromatic hydrocarbons such as those obtained from the
fractionation of petroleum by distillation and/or
extraction or by the alkylation of aromatic hydrocarbons as
for example those obtained by alkylating benzene, toluene,
xylene, naphthalene, diphenyl and the halogen derivatives
suc h as chl orob enzene, chlo rot oluene and
chloronaphthalene. The alkylation may be carried out in
the presence of a catalyst with alkylating agents having
from about 3 to more than 30 carbon atoms. For example
haloparaffins, olefins obtained by dehydrogenation of
paraffins, polyolefins produced from ethylene, propylene,
etc. are all suitable. The alkaryl sulfonates usually
contain from about 9 to about 70 or more carbon atoms,
preferably from about 16 to about 50 carbon atoms per alkyl
substituted aromatic moiety.
The alkaline earth metal compounds which may be
used in neutralizing these alkaryl sulfonic acids to
provide the sulfonates includes the oxides and hydroxides,
alkoxides, carbonates, carboxylate, sulfide, hydrosulfide,
nitrate, borates and ethers of magnesium, calcium, and
barium, sodium, lithium and potassium. Examples are
calcium oxide, calcium hydroxide, magnesium acetate and
magnesium borate. As noted, the alkaline earth metal
~ 35 ~ 1 3 3 4 6 67
compound is used in excess of that required to complete
neutralization of the alkaryl sulfonic acids. GenerallY,
the amount ranges from about 100 to 220%, although it is
preferred to use at least 125%, of the stoichiometric
amount of metal required for complete neutralization.
Various other preparations of basic alkaline earth
metal alkaryl sulfonates are known, such as U.S. Patents
3,150,088 and 3,150,089 wherein overbasing is accomplished
by hydrolysis of an alkoxide-carbonate complex with the
alkaryl sulfonate in a hydrocarbon solvent-diluent oil.
A preferred Mg sulfonate additive is magnesium
alkyl aromatic sulfonate having a total base number ranging
from about 250 to about 400 with the magnesium sulfonate
content ranging from about 25 to about 32 wt. %, based upon
the total weight of this additive system dispersed in
mineral lubricating oil. A preferred Ca sulfonate additive
is calcium alkyl aromatic sulfonate having a total base
number ranging from about 250 to about 500 with the calcium
su~fonate content ranging from about 25 to about 32 wt. %,
based upon the total weight of this additive system
dispersed in mineral lubricating oil.
As an example of a particularly convenient process
for the preparation of the complexes used, an oil-soluble
sulfonic acid, such as a synthetically prepared
didodecylbenzene sulfonic acid, is mixed with an excess of
lime (e.g., 10 equivalents per equivalent of the acid) and
a promoter such as methanol, heptylphenol, or mixture
thereof, and a solvent such as mineral oil, at 50 C-150 C
and the process mass is then carbonated until a homogeneous
mass is obtained. Complexes of sulfonic acids, carboxylic
acids, and mixtures thereof are obtainable by prores~es
such as are described in U.S. Patent No. 3,312,618.
Another example is the preparation of a magnesium sulfonate
normal magnesium salt thereof, an excess of magnesium
oxide, water, and preferably also an alcohol such as
methanol.
- 36 - 1 3 3 4 6 6 ~
The carboxylic acids useful for preparing
sulfonate carboxylate complexes, and carboxylate complexes,
i.e., those obtainable from processes such as the above
wherein a mixture of sulfonic acid and carboxylic acid or a
carboxylic acid alone is used in lieu of the sulfonic acid,
are oil-soluble acids and include primarily fatty acids
which have at least about 12 aliphatic carbon atoms and not
more than about 24 aliphatic carbon atoms. Examples of
these acids include: palmitic, stearic, myristic, oleic,
linoleic, dodecanoic, behenic, etc. Cyclic carboxylic
acids may also be employed. These include aromatic and
cyclo-aliphatic acids. The aromatic acids are those
containing a benzenoid structure (i.e., benzene,
naphthalene, etc.) and an oil-solubilizing radical or
radicals having a total of at least about 15 to 18 carbon
atoms, preferably from about 15 to about 200 carbon atoms.
Examples of the aromatic acids include: stearyl-benzoic
acid, phenyl stearic acid, mono- or polywax-substituted
benzoic or naphthoic acids wherein the wax group consists
of at least about 18 carbon atoms, cetyl hydroxybenzoic
acids, etc. The cycloaliphatic acids contemplated have at
least about 12, usually up to about 30 carbon atoms.
Examples of such acids are petroleum naphthenic acids,
cetyl cyclohexane carboxylic acids, di-lauryl
decahydronaphthalene carboxylic acids, di-octyl
cyclopentane carboxylic acids, etc. The thiocarboxylic
acid analogs of the above acids, wherein one or both of the
oxygen atoms of the carboxyl group are replaced by sulfur,
are also contemplated.
The ratio of the sulfonic acid to the carboxylic
acid in mixtures is at least 1:1 (on a chemical equivalent
basis) and is usually less than 5:1, preferably from 1:1 to
2:1.
The terms "basic salt" and "overbased salt" are
used to designate metal salts wherein the metal is present
in stoichiometrically larger amounts than the ~ulfonic acid
radical.
133461i7
A~ used in the present speCification, the term
"complex" refers to basic metal salts which contain metal
in an amount in excess of that present in a neutral or
normal metal salt. The "base number" of a complex is the
number of milligrams of XOH to which one gram of the
complex i8 equivalent as measured by titration. The
commonly employed methods for preparing the basic salts
involve heating a mineral oil solution of the normal metal
salt of the acid with a metal neutralizing agent such as
the oxide, hydroxide, carbonate, bicarbonate or sulfide at
a temperature above 5-C and filtering the resulting mass.
The use of a "promoter" in the neutralization step to aid
the incorporation of a large excess of metal is known and
is preferred for the preparation of such compositions.
Examples of compounds useful as the promoter include
phenolic substances such as phenol, naphthol, alkyl
phenols, thiophenol, sulfurized alkyl phenols, and
condensation products of formaldehyde with a phenolic
substance; alcohols such as methanol, 2-propanol, octanol,
cellosolve, carbitol, ethylene glycol, stearyl alcohol and
cyclohexanol; and amines such as aniline, phenylene
diamine, phenothiazine, phenol beta-naphthylamine and
dodecylamine.
Usually, the basic composition obtained according
to the above-described method is treated with carbon
dioxide until its total base number (TBN) is less than
about 50, as determined by ASTM procedure D-2896. In many
instances, it is advantageous to form the basic product by
adding the Ca or Mg base portionwise and carbonating after
the addition of each portion. Products with very high
metal ratios (10 or above) can be obtained by this method.
As used herein, the term "metal ratio" refers to the ratio
of total equivalents of alkaline earth metal in the
sulfonate complex to equivalents of sulfonic acid anion
therein. For example, a normal sulfonate has a metal ratio
of 1.0 and a calcium sulfonate complex containing twice as
13~4~67
- 38 -
much c~lcium as the normal salt has a metal ratio of 2Ø
The overbased metal detergent compositions usually have
metal ratios of at least about 1.1, for example, from
about 1.1 to about 30, with metal ratios of from about 2 to
20 being preferred.
It i8 frequently advantageous to react the basic
sulfonate with anthranilic acid, by heating the two at
about 140-200 C. The amount of anthranilic acid used is
generally less than about 1 part (by weight) per 10 parts
of sul~onate, preferably 1 part per 40-200 parts of
sulfonate. The presence of anthranilic acid improves the
oxidation- and corrosion-inhibiting effectiveness of the
sulfonate.
Basic alkali and alkaline earth metal sulfonates
are known in the art and methods for their preparation are
described in a number of patents, such as U.S. Patent Nos.
3,027,325; 3,312,618: and 3,350,308. Any of the sulfonates
described in these and numerous other patents are suitable
for use in the present invention.
The metal detergent inhibitor (e.g., the basic Ca
and Mg salts) are preferably separately prepared and then
admixed in the controlled amounts as provided herein. It
will be generally convenient to admix such separately
prepared detergent inhibitors in the presence of the
diluent or solvent used in their preparation.
Other antioxidants useful in this invention
include oil soluble copper compounds. The copper may be
blended into the oil as any suitable oil soluble copper
compound. By oil soluble we mean the compound is oil
soluble under normal blending conditions in the oil or
additive package. The copper compound may be in the
cuprous or cupric form. The copper may be in the form of
the copper dihydrocarbyl thio- or dithio-phosphates wherein
copper may be substituted for zinc in the compounds and
reactions described above although one mole of cuprous or
cupric oxide may be reacted with one or two moles of the
_ 39 _ 1 3 3 ~ 6 6 7
dithiophosphoric acid, respectively. Alternatively the
copper may be added as the copper salt of a synthetic or
natural carboxylic acid. Examples include C8 to C18
fatty acids such as 2-ethyl hexanoic acid, stearic or
palmitic, but unsaturated acids such as oleic or branched
carboxylic acids such as naphthenic acids of molecular
weight from 200 to 500 or synthetic carboxylic acids are
preferred because of the improved handling and solubility
properties of the resulting copper carboxylates. Also
useful are oil soluble copper dithiocarbamates of the
general formula (RR'NCSS)nCu, where n is 1 or 2 and R and
R' are the same or different hydrocarbyl radicals
containing from 1 to 18 and preferably 2 to 12 carbon atoms
and including radicals such as alkyl, alkenyl, aryl,
aralkyl, alkaryl and cycloaliphatic radicals. Particularly
preferred as R and R' groups are alkyl groups of 2 to 8
carbon atoms. Thus, the radicals may, for example, be
ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl,
amyl, n-hexyl, i-hexyl, n-heptyl, n-octyl, decyl, dodecyl,
octadecyl, 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl,
methylcyclopentyl, propenyl, butenyl, etc. In order to
obtain oil solubility, the total number of carbon atoms
(i.e., R and R') will generally be about 5 or greater.
Copper sulphonates, including alkaryl sulfonates as
described herein above, (i.e., salts of optionally
sulfurized alkylphenols as described hereinabove) phenates,
and acetylacetonates may also be used.
Exemplary of useful copper compounds are copper
(CuI and/or CuII) salts of alkenyl succinic acids or
anhydrides. The salts themselves may be basic, neutral or
acidic. They may be formed by reacting (a) any of the
materials discussed above in the Ashless Dispersant
section, which have at least one free carboxylic acid (or
anhydride) group with (b) a reactive metal compound.
Suitable acid (or anhydride) reactive metal compounds
include those such as cupric or cuprous hydroxides, oxides,
~ 40 - 1 3 3 4 6 67
acetates, borates, and carbonates or basic copper
carbonate.
Examples of the metal salts of this invention are
Cu salts of polyisobutenyl succinic anhydride (hereinafter
referred to as Cu-PIBSA), and Cu salts of polyisobutenyl
succinic acid. Preferably, the selected metal employed is
its divalent form, e.g., Cu+2. The preferred substrates
are polyalkenyl succinic acids in which the alkenyl group
has a number average molecular weight (Mn) greater than
about 700. The alkenyl group desirably has a Mn from
about 900 to 1400, and up to 2500, with a Mn of about 950
being most preferred. Especially preferred, of those
listed above in the section on Dispersants, is
polyisobutylene succinic acid (PIBSA). These materials may
de~irably be dissolved in a solvent, such as a mineral oil,
and heated in the presence of a water solution (or slurry)
of the metal bearing material. Heating may take place
between 70- and about 200-C. Temperatures of 110- to 140-C
are entirely adequate. It may be necessary, depending upon
the salt produced, not to allow the reaction to remain at a
temperature above about 140-C for an extended period of
time, e.g., longer than 5 hours, or decomposition of the
salt may occur.
The copper antioxidants (e.g., Cu-PIBSA,
Cu-oleate, or mixtures thereof) will be generally employed
in an amount of from about 50-500 ppm by weight of the
metal, in the final lubricating or fuel composition.
The copper antioxidants used in this invention are
inexpensive and are effective at low concentrations and
therefore do not add substantially to the cost of the
product. The results obtained are frequently better than
those obtained with previously used antioxidants, which are
expensive and used in higher concentrations. In the
amounts employed, the copper compounds do not interfere
with the performance of other components of the lubricating
compo~ition.
- 41 - ~ 667
While any effective amount of the copper
antioxidant can be incorporated into the lubricating oil
composition, it is contemplated that such effective amounts
be sufficient to provide said lube oil composition with an
amount of the copper antioxidant of from about 5 to 500
(more preferably l0 to 200, still more preferably l0 to
180, and most preferably 20 to 130 (e.g., 90 to 120)) part
per million of added copper based on the weight of the
lubricating oil composition. Of course, the preferred
amount may depend amongst other factors on the quality of
the basestock lubricating oil.
Corrosion inhibitors, also known as anti-corrosive
agents, reduce the degradation of the non-ferrous metallic
parts contacted by the lubricating oil composition.
Illustrative of corrosion inhibitors are phosphosulfurized
hydrocarbons and the products obtained by reaction of a
phosphosulfurized hydrocarbon with an alkaline earth metal
oxide or hydroxide, preferably in the presence of an
alkylated phenol or of an alkylphenol thioester, and also
preferably in the presence of carbon dioxide.
Phosphosulfurized hydrocarbons are prepared by reacting a
suitable hydrocarbon such as a terpene, a heavy petroleum
fraction of a C2 to C6 olefin polymer such as
polyisobutylene, with from S to 30 weight percent of a
sulfide of phosphorus for l/2 to 15 hours, at a temperature
in the range of 65- to 320-C. Neutralization of the
phosphosulfurized hydrocarbon may be effected in the manner
taught in U.S. Patent No. l,969,324.
Other oxidation inhibitors can also be employed in
addition to Component B, to assist, where desired, in
further reducing the tendency of the mineral oils to
deteriorate in service and to thereby reduce the formation
of products of oxidation such as sludge and varnish-like
deposits on the metal surfaces and to reduce viscosity
growth. Such other oxidation inhibitors include alkaline
earth metal salts of alkylphenolthioesters having
133~61i7
- 42 -
preferably CS to C12 alkyl side chains (such as calcium
nonylphenol sulfide, barium t-octylphenyl sulfide, etc.),
diphenyl amine, alkyl diphenyl amines, dioctylphenylamine,
phenyl alpha-naphthylamine (and its alkylated derivatives),
phosphosulfurized hydrocarbons, other sulfurized
hydrocarbons (such as sulfurized phenols, sulfurized alkyl
catechols, and the like), phenols, hindered-phenols,
bis-phenols, catechol, alkylated catechols, etc.
Friction modifiers serve to impart the proper
friction characteristics to lubricating oil compositions
such as automatic transmission fluids.
Representative examples of suitable friction
modifiers are found in U.S. Patent No. 3,933,659 which
discloses fatty acid esters and amides; U.S. Patent No.
4,176,074 which describes molybdenum complexes of polyiso-
butenyl succinic anhydride-amino alkanols; U.S. Patent No.
4,105,571 which discloses glycerol esters of dimerized
fatty acids; U.S. Patent No. 3,779,928 which discloses
alkane phosphonic acid salts; U.S. Patent No. 3,778,375
which discloses reaction products of a phosphonate with an
oleamide; U.S. Patent No. 3,852,205 which discloses
S-carboxy-alkylene hydrocarbyl succinimide, S-carboxy-
alkylene hydrocarbyl succinamic acid and mixtures thereof;
U.S. Patent No. 3,879,306 which discloses N-(hydroxy-
alkyl) alkenyl-succinamic acids or succinimides; U.S.
Patent No. 3,932,290 which discloses reaction products of
di-(lower alkyl) phosphites and epoxides; and U.S. Patent
No. 4,028,258 which discloses the alkylene oxide adduct of
phosphosulfurized N-(hydroxyalkyl) alkenyl succinimides.
The most preferred friction~
modifiers are glycerol mono and dioleates, and succinate
esters, or metal salts thereof, of hydrocar~yl substituted
succinic acids or anhydrides and thiobis alkanols such as
described in U.S. Patent No. 4,344,853.
- 43 -
13~4667
Pour point depressants lower the temperature at
which the fluid will flow or can be poured. Such
depressants are well known. Typical of those additives
which usefully optimize the low temperature fluidity of the
fluid are C8-C18 dialkylfumarate vinyl acetate
copolymers, polymethacrylates, and wax naphthalene.
Foam control can be provided by an antifoamant of
~the polysiloxane type, e.g. silicone oil and polydimethyl
siloxane.
Organic~ oil-soluble compounds useful as rust
inhibitors in this invention comprise nonionic surfactants
such as polyoxyalkylene polyols and esters thereof, and
anionic surfactants such as salts of alkyl sulfonic acids.
Such anti-rust compounds are known and can be made by
conventional means. Nonionic surfactants, useful as
anti-rust additives in the oleaginous compositions of this
invention, usually owe their surfactant properties to a
number of wsak stabilizing groups such as ether linkages.
Nonionic anti-rust agents containing ether linkages can be
made by alkoxylating organic substrates containing active
hydrogens with an excess of the lower alkylene oxides (such
as ethylene and propylene oxides) until the desired number
of alkoxy groups have been placed in the molecule.
The preferred rust inhibitors are polyoxyalkylene
polyols and derivatives thereof. This class of materials
are commercially available from various sources: Pluronic
Polyols from Wyandotte Chemicals Corporation; Polyglycol
112-2, a liquid triol derived from ethylene oxide and
propylene oxide available from Dow Chemical Co.; and
Tergitol, dodecylphenyl or monophenyl polyethylene glycol
ethers, and Ucon, polyalkylene glycols and derivatives,
both available from Union Carbide Corp. These are but a few
of the commercial products suitable as rust inhibitors in
the improved composition of the present invention.
* Trade Mark
~ 44 ~ 1 3 ~ ~ 6 6~
In addition to the polyols per se, the esters
thereof obtained by reacting the polyols with various
carboylic acids are also suitable. Acids useful in
preparing these esters are lauric acid, stearic acid,
succinic acid, and alkyl- or alkenyl-substituted succinic
acids wherein the alkyl-or alkenyl group contains up to
about twenty carbon atoms.
The preferred polyols are prepared as block
polymers. Thus, a hydroxy-substituted compound, R-(OH)n
(wherein n is 1 to 6, and R is the residue of a mono- or
polyhydric alcohol, phenol, naphthol, etc.) is reacted with
propylene oxide to form a hydrophobic base. This base is
then reacted with ethylene oxide to provide a hydrophylic
portion resulting in a molecule having both hydrophobic and
hydrophylic portions. The relative sizes of these portions
can be adjusted by regulating the ratio of reactants, time
of reaction, etc., as is obvious to those skilled in the
art. Thus it is within the skill of the art to prepare
polyols whose molecules are characterized by hydrophobic
and hydrophylic moieties which are present in a ratio
rendering rust inhibitors suitable for use in any lubricant
composition regardless of differences in the base oils and
the presence of other additives.
If more oil-solubility is needed in a given
lubricating composition, the hydrophobic portion can be
increased and/or the hydrophylic portion decreased. If
greater oil-in-water emulsion breaking ability is required,
the hydrophylic and/or hydrophobic portions can be adjusted
to accomplish this.
Compounds illustrative of R-(OH)n include
alkylene polyols such as the alkylene glycols, alkylene
triols, alkylene tetrols, etc., such as ethylene glycol,
propylene glycol, glycerol, pentaerythritol, sorbitol,
mannitol, and the like. Aromatic hydroxy compounds such as
alkylated mono- and polyhydric phenols and naphthols can
also be used, e.g., heptylphenol, dodecylphenol, etc.
- 45 - 1 3346 ~7
Other suitable demulsifiers include the esters
disclosed in U.S. Patents 3,098,827 and 2,674,619,
The liguid polyols available from Wyandotte
Chemical Co. under the name Pluronic Polyols and other
similar polyols are particularly well suited as rust
inhibitors. These Pluronic Polyols correspond to the
formula:
H~(CH2CH2)x(lcHcH2)y(cH2cH2)zH (VIII)
CH3
wherein x, y, and z are integers greater than 1 such that
the -CH2CH2O - groups comprise from about 10% to
about 40% by weight of the total molecular weight of the
glycol, the average molecule weight of said glycol being
from about 1000 to about S000. These products are prepared
by first condensing propylene oxide with propylene glycol
to produce the hydrophobic base
HO(~fH~CH2~0)y~H (IX)
CH3
This condensation product is then treated with ethylene
oxide to add hydrophylic portions to both ends of the
molecule. For best results, the ethylene oxide units
should comprise from about 10 to about 40% by weight of the
molecule. Those products wherein the molecular weight of
the polyol is from about 2500 to 4500 and the ethylene
oxide units comprise from about 10% to about lS% by weight
of the molecule are particularly suitable. The polyols
having a molecular weight of about 4000 with about 10%
attributable to (CH2CH2O) units are particularly good.
Also useful are alkoxylated fatty amines, amides, alcohols
and the like, including such alkoxylated fatty acid
derivatives treated with Cg to C16 alkyl-substituted
phenols (such as the mono- and di-heptyl, octyl, nonyl,
decyl, undecyl, dodecyl and tridecyl phenols), as described
in U.S. Patent 3,849,501.
- 46 - 133 ~6 67
These compositions of our invention may also
contain other additives such as those previously described,
and other metal containing additives, for example, those
containing barium and sodium.
The lubricating composition of the present
invention may also include copper lead bearing corrosion
inhibitors. Typically such compounds are the thiadiazole
polysulphides containing from 5 to 50 carbon atoms, their
derivatives and polymers thereof. Preferred materials are
the derivatives of 1,3,4-thiadiazoles such as those
described in U.S. Patents 2,719,125; 2,719,126; and
3,087,932; especially preferred is the compound 2,5-bis
(t-octadithio)-1,3,4 thiadiazole commercially available as
Amoco 150, or 2,5-bis(nonyldithio)-1,3,4-thiadiazole
available as Amoco 158. Other similar materials also
suitable are described in U.S. Patents 3,821,236;
3,904,537; 4,097,387; 4,107,059; 4,136,043; 4,188,299; and
4,193,882. Derivatives of thiadiazole mercaptans may be
used such as esters, condensation products with halogenated
carboxylic acids, reaction products with aldehydes and
amines, alcohols or mercaptans, amine salts,
dithiocarbamates, reaction products with ashless
dispersants te.g., U.S-A-4140643 and US-A-4136043) and
reaction products with sulfur halides and olefins.
Other suitable additives are the thio and polythio
sulphenamides of thiadiazoles such as those described in
U.K. Patent Specification 1,560,830. When these compounds
are included in the lubricating composition, we prefer that
they be present in an amount from 0.01 to 10, preferably
0.1 to 5.0 weight percent based on the weight of the
composition.
Some of these numerous additives can provide a
mUltiplicity of effects, e.g., a dispersant-oxidation
inhibitor. This approach is well known and need not be
further elaborated herein.
* Trade ~ark
- 47 - 1 3 ~ ~ 6 ~ 7
Compositions when containing these conventional
additiveQ are typically blended into the base oil in
amounts effective to provide their normal attendant
function. Representative effective amounts of such
additives (as the respective active ingredients) in the
fully formulated oil are illustrated as follows:
Wt.% A.I. Wt.% A.I.
Com~ositions ~Preferred) (Broad~
Component A 4-7 3-10
Component B 2.2-4 2-6
Component C 1.0-2 0.8-3
Viscosity Modifiers 0-4 0-12
Detergents 0.01-0.4 0.01-0.6
Corrosion Inhibitors 0.01-0.5 0-1.5
Other Oxidation Inhibitors 0-1.5 0-5
Pour Point Depressants 0.01-0.5 .01-1.0
Anti-Foaming Agents 0.001-0.01 .001-0.1
Other Anti-Wear Agents 0.001-1.5 0-5
Friction Modifiers 0.01-1.5 0-5
Lubricating Base Oil Balance Balance
When other additives are employed, it may be
desirable, although not necessary, to prepare additive
concentrates comprising concentrated solutions or disper-
sions of the novel detergent inhibitor/antiwear agent
mixtures of this invention (in concentrate amounts
hereinabove described), together with one or more of said
other additives (said concentrate when constituting an
additive mixture being referred to herein as an
additive-package) whereby several additives can be added
simultaneously to the base oil to form the lubricating oil
composition. Dissolution of the additive concentrate into
the lubricating oil may be facilitated by solvents and by
mixing accompanied with mild heating, but this is not
essential. The concentrate or additive-package will
typically be formulated to contain the additives in proper
amounts to provide the desired concentration in the final
- 48 - 133~6~7
formulation when the additive-package is combined with a
predetermined amount of base lubricant- Thus, the detergent
inhibitor/antiwear agent mixtureg of the present invention
can be added to small amountg of base oil or other
compatible solvents along with other desirable additives to
form additive-packages containing active ingredients in
collective amounts of typically from about 2.5 to about
90%, and preferably from about 15 to about 75%, and most
preferably from about 25 to about 60% by weight additives
in the appropriate proportions with the remainder being
base oil.
The final formulations may employ typically about
10 wt. % of the additive-package with the remainder being
base oil.
All of said weight percent~ expressed herein
(unless otherwise indicated) are based on active ingredient
(A.I.) content of the additive, and/or upon the total
weight of any additive-package, or formulation which will
be the sum of the A.I. weight of each additive plus the
weight of total oil or diluent.
This invention will be further understood by
reference to the following examples, wherein all parts are
parts by weight, unless otherwise noted and which include
preferred embodiments of the invention.
- 49 - 1334667
EXAMPLES
A series of fully formulated SAE 15W40 lubricating
oils are prepared having the components identified in Table
I.
TABT~ I. T~T FORMUT~TIONS ~VOT. %~
Comparative Comparative Example Example
A B 1 2
PIBSA-PAM
Dispersant (1) 7.57 5.54 7,57 7,57
Sulfurized Alkyl
Phenol Antioxidant(2) 2.83 1.8 2.83 2.83
Zinc Dialkyl
Dithiophosphate
Antiwear Agent (3) 1.75 1.45 1.35 1.35
Overbased Mg Sulfona~4e
Detergent Inhibitor ~ )1.19 1.45 0.51 0.51
Viscosity 5~dex
Improver ( 8.82 -- 8.20 8.40
Base Oil (6) Balance Balance Balance Balance
TBN (7) 8.4 8.0 5.0 5.0
SASH (8) 0.85 0.84 0.44 0 5
13346~7
-- 51 --
1 o ~ ~ C C ~ ~ Z ) C ~
~ C~ 3 ~ ~ m ~ 3
a ~ O ~ ' X c
z~ m O ~ r ~ O E~ ~
3u~ ~ ~ ~ O ~ c--~ U o x.~ ~,
.~ C ~ D~ c O ~ ~ d~ C C
C ~r ~a c o ~ ~ & ~ U 3 ~ ~,
O ~ , C
~ ~ ~ O r ~ ~ 3 0
D 3~SrJ~ sE~s~ ~ Uc 'o-Jc~
m ~ ~ ~ o ~ ~ ~ A O ~ A
.~ ~ U S-~ C ~ ~ SU ~) ~ L Cl U
' ~ u ~ 3 c~ ~ o
" 3 U ~ j 3 U~ 3 ~ y C C h z
o U~ N ~ C ~ C a~ U O ~ O
O V U ~ O S ~ ,a ~ r ~ ~ X S
~ ~3--~ ~ U 3 ~ 3 ~ '5 '~
~1 ~ o S ~U O ~ o ~ q O
3 ~ o ~ X
o 3 o ~ ~ ~ ~ o ~ o ~ 3 ~ C C ~ -
, S ~ U ~ ~ V U 3 ,~ S ~ S V ~, ~ S
~ ~ N ,~ ~ E ~ 0 C
L~ m o o ~
U ~ 3 ~-I C
, 3 ~ CO ~ ~ U C~ ~ . C
x ~ , e ~ ~ L~ L ~ C u~ ,C _ .rl ~ ~
-~1CO ~ 1~1 ~ ~ O C 0 ~ ~ X tr~--I O '~ JJ--4 Ll O O
Ll ~ u~ e o 3 ~ n ~ U
U~
_ _ _ _ _ _ _ _
Z -- ---- _ _
- 52 ~ 1 334 6 67
The formulations are subjected to a Cummins
* ..
NTC-400 field test (loads = refrigerated trailers; 80,000
lbs. gross vehicle weight, approx. 80% load factor;
continental United States service ~ex-Alaska), with
majority of hauling from Dallas to Pacific Northwest,
wherein diesel fuels <0.3 wt% sulfur were employed.
Also included in the above tests are the following
commercial SAE l5W40 lubricating oils. These formulations
include ashless dispersant, overbased alkaline earth metal
detergent inhibitors, and zinc dihydrocarbyl
dithiophosphate antiwear agents.
Comparative
Test Oils Wt% SASHTBN (D2896)
Oil C 1.0 10
Oil D 1.1 12
Oil E 0.72 6.9
Oil F 1.0 10
Oil G 1.0 8
Oil H 1.0 8
Oil I 1.0 8
Oil J 0~9 7
Oil K l.9S 14
The data thereby obtained are set forth in Table
III.
* Trade Mark
1~3~7
-- 53 --
Y ~ ~ ' ~ ~ ~ ~ o o ~ ~ ~ ~
O ~ ~ ~ ~ ~ ~ 0 ~0 ~ O O O O O O
~ O ~ ~ ~ o . o ~ o ~~ ~ ~ ~
~0 ~3 ~ ~ o r j ~ ~ N C~ ~` 8o o o ' ~ o o o o
Y ~ ~ ~ ~ ~ 'n O ~0
Q ~ o o O o ~
Z ~ ~o In ~ O ~ r ~O O O ~ O O O O O O
~ ~` ~ o '` ~ o ~` 8 ~o o o o o o o o
Y ~o ~ ~ . . . o . . . o o
` æ ~ o ~ 8 8 8 ~ o o o o
o. r ~ ~ 1 ~ o ~ ~ ... ~ r .... o o
Y ~ l ~ o ~'`, o u o ~
8 '~ o ~ 8 8 8 r~ o o o o
q ~ o - O r~ o. - - - o o
y ~ o
gl ~"~ O ~ ~ ~~ o ;~; 8 8 o ~
~ s ~o~ o ~,~ .... o0 ~3
~3 ~Y ~ o ~` o o l ~ ~ 3
,~ ~ ~ o ~ ~ o 8 8 ~ o o ~o
r o o r~ .... o o
O ~ 8 8 O~ ~ o o o ~ 0 0
~3 ~ 8 ~ 0~
0 z ~ 1~7 8 8 8 N O O O
o ,~ ~ o ~ ~ ~ 3 8. 8. . u7 ~ o. o. o. o. 0 0
o ~ o 8 8 ~o O O O ~n
C~ ~ O ~ '~ O O ~ 1~1 O N ~ ~1 ~ O ~ . . . - O O
Y ~ 0 (` 0 ~3
O r` 0 ~ ~ ~O r~ 8 8 0 ~o o o o ~i
o ~ ~ ~ o ~ o o
3~ 5 ~ ~"` '` ' 808
~ i ~4 ~ ~ ~ ~o o eo ~ o o o o
~ 9~
1334~67
- 54 -
From the data in Table III, it can be seen that
the oil of Example 1 provides superior crownland
cleanliness without sacrificing any of the remaining
performance properties.
~MPTF 3
The low ash lubricating oil of Example 1 was
subjected to a series of additional engine tests, and the
data thereby obtained are summarized in Table IV. As can
be seen, the oil of Example 1 passes all of the
requirements of the American Petroleum Institute's CE
specification for commercial heavy duty diesel lubricating
oils.
_ 55 1334G67
oo co a
U
X X
x e
x ~ ~ ~ eo ~ ~ o ~ ~o
o ~ ~ ~ ~r o c
~ ~ o o O O O O ~ o . ~
C~ o o . ~ . U~ ~ o . ~ ~- o
o C~ ~ o ~O O ~ ~ ~ o C
P ~ .~
~ o
:~ ~ o
r~ ~ ~, O O a' O
U~ t`~ O ~ O ~ o N
1~ C
9 ~ 1 O C O 0
-- ~ ~ e ~ o ~
~ O ~ X c m ~ao c ~0 U E~
- 56 - ~ 7
The low ash oils of thi-~ invention are preferablY
employed in heavy duty diesel engines which employ normallY
liquid fuels having a sulfur content of less than 1 wt.%,
more preferably less than 0.5 wt.%, still more preferably
less than 0.3 wt.% (e.g-, from about 0.1 to about 0.3 wt%),
and most preferably less than 0.1 wt.% (e.g., from 100 to
500 ppm sulfur). Such normally liquid fuels include
hydrocarbonaceous petroleum distillate fuels such as diesel
~uels or fuel oils as defined by ASTM Specification D396.
Compression ignited engines can also employ normally liquid
fuel compositions comprising non-hydrocarbonaceous
materials such as alcohols, ethers, organonitro compounds
and the like (e.g., methanol, ethanol, diethyl ether,
methyl ethyl ether, nitromethane) are also within the scope
of this 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-hydrocarbonaceous materials are also contemplated.
Examples of such mixtures are combinations of diesel fuel
and ether. Particularly preferred is No. 2 diesel fuel.
The lubricating oils of this invention are
particularly useful in the crankcase of diesel engines
having cylinders (generally from 1 to 8 cylinders or more
per engine) wherein there is housed for vertical cyclic
reciprocation therein a piston provided with a tight top
land, that is, cylinders wherein the distance between the
piston's top land and the cylinder wall liner is reduced to
minimize the amount of particulates generated in the
cylinder's firing chamber (wherein the fuel is combusted to
generate power). Such tight top lands can also provide
improved fuel economy and an increase in the effective
compression ratio in the cylinder. The top land comprises
the region of the generally cylindrical piston above the
top piston ring groove, and the top land, therefore, is
generally characterized by a circular croRs-section (taken
133~7
- 57 -
along the longitudinal axis of the piston). The outer
periphery of the top land can comprise a substantially
vertical surface which is designed to be substantiallY
parallel to the vertical walls of the cylinder liner.
(Such top lands are herein referred to as "cylindrical top
landsn.) Or, as is preferred, the top land can be tapered
inwardly toward the center of the piston from the point at
which the top land adjoins the top piston ring groove and
the uppermost surface of the piston, i.e., the "crown".
The distance between the top land and the cylinder wall
liner, herein called the "top land clearance", will
preferably range from about 0.010 to 0.030 inch for
cylindrical top lands . For tapered top lands, the lower
top land clearance (that is, the top land clearance at the
point at which the top land is adjoined to the top piston
ring groove) is preferably from about 0.005 to 0.030 inch,
and more preferably from about 0.010 to 0.020 inch, and the
upper top land clearance, that is, the top land clearance
at the piston crown, is preferably from about 0.010 to
0.045 inch, and more preferably from about 0.015 to 0.030
inch. While the top land clearance can be less than the
dimensions given above (e.g., less than 0.005 inch), if
such lesser distances do not result in undesired contact of
the top land portion of the piston with the cylinder wall
liner during operation of the engine, which is undesirable
due to the resultant damage to the liner. Generally, the
height of the top land (that is, the vertical distance, as
measured along the cylinder wall liner, from the bottom of
the top land to the top of the top land) is from about 0.1
to about 1.2 inch, which is generally from about 0.8 to 1.2
inch for 4-cycle diesel engines and from about 0.1 to 0.5
inch for 2-cycle diesel engines. The design of diesel
engines and such pistons having such tight top lands is
within the skill of the skilled artisan and need not be
further described herein.
The principles, preferred embodiments, and modes
of operation of the present invention have been described
- 58 - 1 3 3 ~ 6 ~ 7
in the foregoing specification. The invention which is
intended to be protected herein, however, is not to be
construed as limited to the particular forms disclosed,
since these are to be regarding as illustrative rather than
restrictive. Variations and changes may be made by those
skilled in the art without departing from the spirit of the
invention .
