U.S. patent application number 15/613696 was filed with the patent office on 2018-12-06 for methods for improving resistance to timing chain wear with a multi-component detergent system.
This patent application is currently assigned to Afton Chemical Corporation. The applicant listed for this patent is Afton Chemical Corporation. Invention is credited to Guillaume Carpentier, Kristin Fletcher, Paul Ransom.
Application Number | 20180346839 15/613696 |
Document ID | / |
Family ID | 61622785 |
Filed Date | 2018-12-06 |
United States Patent
Application |
20180346839 |
Kind Code |
A1 |
Fletcher; Kristin ; et
al. |
December 6, 2018 |
METHODS FOR IMPROVING RESISTANCE TO TIMING CHAIN WEAR WITH A
MULTI-COMPONENT DETERGENT SYSTEM
Abstract
A method for reducing timing chain stretch in an engine
comprising a step of lubricating said timing chain with a
lubricating oil composition that includes a major amount of a base
oil; and a minor amount of an additive package including at least
one overbased calcium phenate detergent having a total base number
of at least 150 mg KOH/g, measured by the method of ASTM D-2896, at
least one calcium sulfonate detergent; and at least one
magnesium-containing detergent. The lubricating oil composition has
a weight ratio of total calcium from the at least one calcium
sulfonate detergent to total calcium and magnesium in the
lubricating oil composition of from about 0.06 to less than about
0.45.
Inventors: |
Fletcher; Kristin;
(Midlothian, VA) ; Ransom; Paul; (Marsden, GB)
; Carpentier; Guillaume; (Berkshire, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Afton Chemical Corporation |
Richmond |
VA |
US |
|
|
Assignee: |
Afton Chemical Corporation
Richmond
VA
|
Family ID: |
61622785 |
Appl. No.: |
15/613696 |
Filed: |
June 5, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2040/40 20200501;
C10M 2215/065 20130101; C10N 2030/52 20200501; C10M 2207/26
20130101; C10M 159/22 20130101; C10M 169/042 20130101; C10M
2207/262 20130101; C10M 159/24 20130101; C10N 2030/06 20130101;
C10M 2223/12 20130101; C10M 2207/028 20130101; C10M 2219/089
20130101; C10M 2201/085 20130101; C10M 2215/064 20130101; C10N
2010/04 20130101; C10M 2219/046 20130101; C10N 2040/255 20200501;
C10M 2223/045 20130101; C10M 2207/028 20130101; C10N 2010/04
20130101; C10M 2219/089 20130101; C10N 2010/04 20130101; C10M
2207/262 20130101; C10N 2010/04 20130101; C10M 2207/26 20130101;
C10N 2010/04 20130101; C10M 2201/085 20130101; C10N 2010/04
20130101; C10M 2219/046 20130101; C10N 2010/04 20130101; C10M
2207/028 20130101; C10N 2010/04 20130101; C10M 2219/089 20130101;
C10N 2010/04 20130101; C10M 2207/262 20130101; C10N 2010/04
20130101; C10M 2207/26 20130101; C10N 2010/04 20130101; C10M
2201/085 20130101; C10N 2010/04 20130101; C10M 2219/046 20130101;
C10N 2010/04 20130101 |
International
Class: |
C10M 101/04 20060101
C10M101/04; C10M 129/12 20060101 C10M129/12 |
Claims
1. A method for reducing timing chain stretch of a timing chain in
an engine comprising a step of lubricating said timing chain with a
lubricating oil composition comprising: a major amount of a base
oil; and a minor amount of an additive package including: a) at
least one overbased calcium phenate detergent having a total base
number of at least 150 mg KOH/g, measured by the method of ASTM
D-2896; b) at least one calcium sulfonate detergent; and c) at
least one magnesium-containing detergent; wherein the lubricating
oil composition has a weight ratio of total calcium from the at
least one calcium sulfonate detergent to total calcium and
magnesium in the lubricating oil composition of from 0.06 to
0.35.
2. The method according to claim 1, wherein the at least one
magnesium-containing detergent is overbased having a total base
number of at least 225 mg KOH/g, measured by the method of ASTM
D-2896.
3. The method according to claim 1, wherein the at least one
magnesium-containing detergent is selected from an overbased
magnesium phenate, overbased magnesium sulfur containing phenates,
overbased magnesium sulfonates, overbased magnesium calixarates,
overbased magnesium salixarates, overbased magnesium salicylates,
overbased magnesium carboxylic acids, overbased magnesium
phosphorus acids, overbased magnesium mono- and/or
di-thiophosphoric acids, overbased magnesium alkyl phenols,
overbased magnesium sulfur coupled alkyl phenol compounds,
overbased magnesium methylene bridged phenols and combinations
thereof.
4. The method according to claim 1, wherein the at least one
calcium sulfonate detergent is overbased having a total base number
of at least 225 mg KOH/g, measured by the method of ASTM
D-2896.
5. (canceled)
6. The method of claim 1, wherein the additive package further
comprises one or more additives selected from the group consisting
of antioxidants, friction modifiers, pour point depressants, and
viscosity index improvers.
7. The method of claim 6, wherein the antioxidant is an oil soluble
molybdenum complex.
8. The method of claim 1, wherein the base oil has viscosity grade
of 5W-X or 0W-X and the lubricating oil composition comprises one
or more antioxidants selected from an aromatic amine, an alkylated
diphenylamine, a phenyl-alpha-naphthylamine, and an alkylated
phenyl-alpha-naphthylamine.
9. The method of claim 1, wherein the lubricating oil composition
contains from about 50 ppm to about 1650 ppm of calcium provided by
the at least one calcium sulfonate detergent, based on a total
weight of the lubricating oil composition.
10. The method of claim 1, wherein the lubricating oil composition
contains from about 100 ppm to about 2000 ppm of calcium provided
by the at least one calcium phenate detergent, based on a total
weight of the lubricating oil composition.
11. The method of claim 1, wherein the lubricating oil composition
contains from about 400 ppm to about 2200 ppm of calcium provided
by all of the overbased calcium-containing detergents, based on a
total weight of the lubricating oil composition.
12. The method of claim 1, wherein the total amount of calcium in
the lubricating oil composition is from about 1000 ppm to less than
about 3090 ppm.
13. The method of claim 1, wherein the lubricating oil composition
contains from about 50 ppm to about 1650 ppm of magnesium provided
by the at least one magnesium-containing detergent, based on a
total weight of the lubricating oil composition.
14. The method of claim 1, wherein the lubricating oil composition
contains a total of from about 500 ppm to less than 3100 ppm of
magnesium and calcium, based on a total weight of the lubricating
oil composition.
15. The method of claim 1, wherein the lubricating oil composition
further comprises a metal dialkyl dithiophosphate.
16. The method of claim 1, wherein the engine is a spark ignition
engine.
17. The method of claim 1, wherein the engine is a spark ignition
passenger car gasoline engine.
18. The method of claim 1, wherein the lubricating oil composition
is capable of reducing the timing chain stretch in an engine to
0.1% or less, as measured by the Ford Chain Wear Test over 216
hours.
Description
TECHNICAL FIELD
[0001] The disclosure relates to methods for reducing timing chain
stretch using lubricating compositions and to lubricating oil
compositions and lubricating oil additive compositions for
lubrication of the timing chain.
BACKGROUND
[0002] In an internal combustion engine there may be a metal chain,
also known as a timing chain, comprised of bearing pins, rollers,
bushings, and an inner and outer plate. Due to the significant load
and friction exerted on these components, the timing chain is
susceptible to significant wear including corrosive wear. To
address this problem lubricants are formulated to reduce wear
between moving parts where there is metal to metal contact.
[0003] Chain elongation, or timing chain stretch, is a phenomenon
that occurs in internal combustion engines with a timing chain that
has deteriorated due to wear. Chain elongation mainly occurs at the
pin, bushing and side plate wear contact interfaces. Timing chain
stretch can lead to significant problems in operation of the
internal combustion engine and can have an effect on engine
performance, fuel economy and emissions.
[0004] Timing chain stretch can cause a deviation from the desired
timing of parts operatively connected to the timing chain. Such a
deviation may be caused, for example, by the chain skipping one or
more sprocket teeth during operation, or by exceeding the
adjustability of the cam phasers. These deviations may alter the
relative timing of the valves and ignition. Intake valve timing
affects when the air and/or fuel mixture is drawn into the
cylinder. Exhaust valve timing affects power output as power can be
lost as a result of escape of gas via the exhaust valve if the
exhaust valve does not open at the appropriate time. Additionally,
unburned hydrocarbon emissions can increase when exhaust valve
timing is not correct since unburned combustion gas may escape via
the exhaust valve under such circumstances.
[0005] The effects of different base oils on diesel engine timing
chain wear were investigated in, "Investigation of Lubrication
Effect on a Diesel Engine Timing Chain Wear," Polat, Ozay, M. Sc.
Thesis Istanbul Technical University Institute of Science and
Technology (January 2008). This thesis concluded that the selection
of base oil could influence timing chain wear in diesel
engines.
[0006] Timing chain wear in light-duty diesel engines is due to a
variety of factors one of which is the contribution of soot to
abrasive wear. Li, Shoutian, et al., "Wear in Cummins M-11/EGR Test
Engines," Society of Automotive Engineers, Inc. (2001), paper no.
2002-01-1672. This article mentions that in engines with an exhaust
gas recirculation (EGR) system, soot caused abrasive wear on
liners, crossheads and top ring faces. The article also mentions
that the main focus of soot-induced wear in non-EGR diesel engines
has been on roller pin wear in the GM 6.2 L engine and crosshead
wear in the Cummins M-11 engine.
[0007] Timing chain stretch in gasoline engines is typically the
result of roller pin wear. As a result, prior art methods for
addressing timing chain stretch typically focus on use and
selection of anti-wear agents. In TGDi engines, soot is a
by-product of gasoline engine combustion and thus timing chain
stretch may occur in such engines due to soot production and the
resultant abrasive wear, particularly roller pin wear.
[0008] In some cases, dispersants and dispersant viscosity index
improvers have been used to address wear problems. For example,
U.S. Pat. No. 7,572,200 B2 discloses a chain drive system that
employs a lubricant designed to coat the sliding parts of the
system, including the chain and sprocket, with a thin hard carbon
coating film having a hydrogen content of 10 atomic percent or less
to reduce the amount of friction and wear on the chain drive
system.
[0009] U.S. Pat. No. 8,771,119 B2 discloses a lubricating
composition for a chain which comprises 80-95% by mass of a
lubricant which is liquid at room temperature and 5-20% by mass of
a wax that is a solid at room temperature. The addition of the wax
is said to provide better abrasion resistance and provide a chain
with elongation resistance and a longer life.
[0010] U.S. Pat. No. 7,053,026 B2 discloses a method for
lubricating a conveyor chain system. Conveyor chains may be exposed
to high temperatures and usually require polyol ester based
lubricants. This patent focuses on reducing chain wear and
minimizing deposits on chain surfaces by using a mixture of mineral
oil, poly(isobutylene) and polyol ester.
[0011] The foregoing references do not provide an adequate solution
for minimizing timing chain stretch in internal combustion engines.
For example, the proposed use of dispersants for this purpose has
been found to provide inadequate protection against timing chain
stretch. Thus, the present disclosure provides a method of
employing calcium detergents and detergent combinations in order to
provide greater reductions in timing chain stretch than is provided
by combinations of conventional anti-wear agents and/or
dispersants.
SUMMARY AND TERMS
[0012] In a first aspect, disclosed is a method for reducing timing
chain stretch of a timing chain in an engine comprising a step of
lubricating said timing chain with a lubricating oil composition
comprising:
[0013] a major amount of a base oil; and
[0014] a minor amount of an additive package including: [0015] a)
at least one overbased calcium phenate detergent having a total
base number of at least 150 mg KOH/g, measured by the method of
ASTM D-2896; [0016] b) at least one calcium sulfonate detergent;
and [0017] c) at least one magnesium-containing detergent. The
lubricating oil composition has a weight ratio of total calcium
from the at least one calcium sulfonate detergent to total calcium
and magnesium in the lubricating oil composition of from about 0.06
to less than about 0.45.
[0018] In the foregoing embodiment, the at least one
magnesium-containing detergent may be overbased having a total base
number of at least 225 mg KOH/g, or at least about 300 mg KOH/g, or
about 350 to about 500 mg KOH/g, all as measured by the method of
ASTM D-2896.
[0019] In each of the foregoing embodiments, the at least one
magnesium-containing detergent may be selected from overbased
magnesium phenate, overbased magnesium sulfur containing phenates,
overbased magnesium sulfonates, overbased magnesium calixarates,
overbased magnesium salixarates, overbased magnesium salicylates,
overbased magnesium carboxylic acids, overbased magnesium
phosphorus acids, overbased magnesium mono- and/or
di-thiophosphoric acids, overbased magnesium alkyl phenols,
overbased magnesium sulfur coupled alkyl phenol compounds,
overbased magnesium methylene bridged phenols and combinations
thereof.
[0020] In each of the foregoing embodiments, the at least one
calcium phenate detergent may be overbased having a total base
number of at least 150 mg KOH/g, or at least about 225 mg KOH/g, at
least 225 mg KOH/g to about 400 mg KOH/g, at least about 225 mg
KOH/g to about 350 mg KOH/g or about 230 to about 350 mg KOH/g, all
as measured by the method of ASTM D-2896.
[0021] In each of the foregoing embodiments, the at least one
calcium sulfonate detergent may be overbased having a total base
number of at least 225 mg KOH/g, or about 225 to about 500 mg
KOH/g, or about 290 to about 500 mg KOH/g, or about 250 mg KOH/g to
about 400 mg KOH/g or about 300 mg KOH/g to about 400 mg KOH/g
measured by the method of ASTM D-2896.
[0022] In each of the foregoing embodiments, the lubricating oil
composition may have a weight ratio of total calcium from the at
least one calcium sulfonate detergent to total calcium and
magnesium in the lubricating oil composition of from about 0.06 to
about 0.4, or from about 0.06 to about 0.35.
[0023] In each of the foregoing embodiments, the additive package
may further comprise one or more additives selected from the group
consisting of antioxidants, friction modifiers, pour point
depressants, and viscosity index improvers.
[0024] In each of the foregoing embodiments, the antioxidant may be
an oil soluble molybdenum complex, or an organomolybdenum complex
of an organic amide, or a sulfur-free organomolybdenum complex of
an organic amide.
[0025] In each of the foregoing embodiments, the base oil may have
a SAE J 300 viscosity grade of 5W-X or 0W-X and the lubricating oil
composition may comprise one or more antioxidants selected from an
aromatic amine, an alkylated diphenylamine, a
phenyl-alpha-naphthylamine, an alkylated
phenyl-alpha-naphthylamine, and an alkylated arylamine, nonyl
diphenylamine, di-nonyl diphenylamine, octyl diphenylamine, and
di-octyl diphenylamine.
[0026] In each of the foregoing embodiments, the lubricating oil
composition may contain from about 50 ppm to about 1650 ppm, or
from about 80 ppm to about 1250 ppm, or from about 100 ppm to about
900 ppm of calcium provided by the at least one calcium sulfonate
detergent, based on a total weight of the lubricating oil
composition.
[0027] In each of the foregoing embodiments, the lubricating oil
composition may contain from about 100 ppm to about 2000 ppm, or
from about 250 ppm to about 1800 ppm, or from about 600 ppm to
about 1500 ppm of calcium provided by the at least one calcium
phenate detergent, based on a total weight of the lubricating oil
composition.
[0028] In each of the foregoing embodiments, the lubricating oil
composition may contain from about 400 ppm to about 2200 ppm, or
from about 500 ppm to about 1700 ppm, or from about 600 ppm to
about 1400 ppm, or less than 1400 ppm of calcium provided by all of
the overbased calcium-containing detergents, based on a total
weight of the lubricating oil composition.
[0029] In each of the foregoing embodiments, the total amount of
calcium in the lubricating oil composition may be from about 1000
ppm to less than about 3090 ppm, or about 1200 ppm to about 2000
ppm, or about 1300 ppm to about 1600 ppm.
[0030] In each of the foregoing embodiments, the lubricating oil
composition may contain from about 50 ppm to about 1650 ppm, or
from about 80 ppm to about 1250 ppm, or from about 250 ppm to about
1100 ppm of magnesium provided by the at least one
magnesium-containing detergent, based on a total weight of the
lubricating oil composition.
[0031] In each of the foregoing embodiments, the lubricating oil
composition may contain a total of from about 500 ppm to less than
3100 ppm, or from about 800 ppm to about 3000 ppm, or from about
1500 ppm to about 2700 ppm of magnesium and calcium, based on a
total weight of the lubricating oil composition.
[0032] In each of the foregoing embodiments, the base oil can be at
least one selected from the group consisting of a Group II base
oil, a Group III base oil, a Group IV base oil and a Group V base
oil. In each of the foregoing embodiments, the lubricating oil
composition may comprise greater than 50 wt. % of a Group II base
oil, a Group III base oil or a combination thereof, or greater than
80 wt. % or greater than 90 wt. % of a Group II base oil, a Group
III base oil or a combination thereof.
[0033] In each of the foregoing embodiments, the lubricating oil
composition may further comprise a metal dialkyl dithiophosphate,
or a zinc dialkyl dithiophosphate.
[0034] In each of the foregoing embodiments, the lubricating oil
composition may comprise not more than 10 wt. % of a Group IV base
oil, a Group V base oil, or a combination thereof.
[0035] In each of the foregoing embodiments, the lubricating oil
compositions may comprise less than 5 wt. % of a Group V base
oil.
[0036] In each of the foregoing embodiments, the overbased
calcium-containing detergents may optionally exclude overbased
calcium salicylate detergents.
[0037] In each of the foregoing embodiments, the lubricating oil
composition may not contain any Group IV base oils.
[0038] In each of the foregoing embodiments, the lubricating oil
composition may not contain any Group V base oils.
[0039] In each of the foregoing embodiments, the engine may be a
spark ignition engine.
[0040] In each of the foregoing embodiments, the engine may be a
spark ignition passenger car gasoline engine.
[0041] In each of the foregoing embodiments, the lubricating oil
composition may be capable of reducing the timing chain stretch in
an engine to 0.1% or less, or 0.1% to 0.01%, each as measured by
the Ford Chain Wear Test over 216 hours.
[0042] Additional features and advantages of the disclosure may be
set forth in part in the description which follows, and/or may be
learned by practice of the disclosure. The features and advantages
of the disclosure may be further realized and attained by means of
the elements and combinations particularly pointed out in the
appended claims.
[0043] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention as
claimed.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The following definitions of terms are provided in order to
clarify the meanings of certain terms as used herein.
[0045] The terms "oil composition," "lubrication composition,"
"lubricating oil composition," "lubricating oil," "lubricant
composition," "lubricating composition," "fully formulated
lubricant composition," "lubricant," "crankcase oil," "crankcase
lubricant," "engine oil," "engine lubricant," "motor oil," and
"motor lubricant" are considered synonymous, fully interchangeable
terminology referring to the finished lubrication product
comprising a major amount of a base oil plus a minor amount of an
additive composition.
[0046] As used herein, the terms "additive package," "additive
concentrate," "additive composition," "engine oil additive
package," "engine oil additive concentrate," "crankcase additive
package," "crankcase additive concentrate," "motor oil additive
package," "motor oil concentrate," are considered synonymous, fully
interchangeable terminology referring the portion of the
lubricating composition excluding the major amount of base oil
stock mixture. The additive package may or may not include the
viscosity index improver or pour point depressant.
[0047] As used herein, the term "hydrocarbyl substituent" or
"hydrocarbyl group" is used in its ordinary sense, which is
well-known to those skilled in the art. Specifically, it refers to
a group having a carbon atom directly attached to the remainder of
the molecule and having predominantly hydrocarbon character.
Examples of hydrocarbyl groups include: [0048] (a) hydrocarbon
substituents, that is, aliphatic (e.g., alkyl or alkenyl),
alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and
aromatic-, aliphatic-, and alicyclic-substituted aromatic
substituents, as well as cyclic substituents wherein the ring is
completed through another portion of the molecule (e.g., two
substituents together form an alicyclic moiety); [0049] (b)
substituted hydrocarbon substituents, that is, substituents
containing non-hydrocarbon groups which, in the context of this
disclosure, do not alter the predominantly hydrocarbon substituent
(e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,
mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and
sulfoxy); and [0050] (c) hetero substituents, that is, substituents
which, while having a predominantly hydrocarbon character, in the
context of this disclosure, contain other than carbon in a ring or
chain otherwise composed of carbon atoms. Heteroatoms may include
sulfur, oxygen, and nitrogen, and encompass substituents such as
pyridyl, furyl, thienyl, and imidazolyl. In general, no more than
two, for example, no more than one, non-hydrocarbon substituent
will be present for every ten carbon atoms in the hydrocarbyl
group; typically, there will be no non-hydrocarbon substituents in
the hydrocarbyl group.
[0051] As used herein, the term "percent by weight", unless
expressly stated otherwise, means the percentage the recited
component represents to the weight of the entire composition.
[0052] The terms "soluble," "oil-soluble" or "dispersible" used
herein may, but do not necessarily, indicate that the compounds or
additives are soluble, dissolvable, miscible, or capable of being
suspended in the oil in all proportions. The foregoing terms do
mean, however, that they are, for instance, soluble, suspendable,
dissolvable, or stably dispersible in oil to an extent sufficient
to exert their intended effect in the environment in which the oil
is employed. Moreover, the additional incorporation of other
additives may also permit incorporation of higher levels of a
particular additive, if desired.
[0053] The term "TBN" as employed herein is used to denote the
Total Base Number in mg KOH/g of the composition as measured by the
method of ASTM D2896.
[0054] The term "alkyl" as employed herein refers to straight,
branched, cyclic, and/or substituted saturated chain moieties of
from about 1 to about 100 carbon atoms.
[0055] The term "alkenyl" as employed herein refers to straight,
branched, cyclic, and/or substituted unsaturated chain moieties of
from about 3 to about 10 carbon atoms.
[0056] The term "aryl" as employed herein refers to single and
multi-ring aromatic compounds that may include alkyl, alkenyl,
alkylaryl, amino, hydroxyl, alkoxy and halo substituents, and/or
heteroatoms including, but not limited to, nitrogen, oxygen, and
sulfur.
[0057] Unless stated otherwise, all percentages are in weight
percent, all ppm values are parts per million by weight (ppmw) and
all molecular weights are number average molecular weights.
[0058] It must be noted that as used herein and in the appended
claims, the singular forms "a", "an", and "the" include plural
references unless the context clearly dictates otherwise.
Furthermore, the terms "a" (or "an"), "one or more", and "at least
one" can be used interchangeably herein. The terms "comprising",
"including", "having" and "constructed from" can also be used
interchangeably.
[0059] It is to be understood that each component, compound,
substituent, or parameter disclosed herein is to be interpreted as
being disclosed for use alone or in combination with one or more of
each and every other component, compound, substituent, or parameter
disclosed herein.
[0060] It is also to be understood that each amount/value or range
of amounts/values for each component, compound, substituent, or
parameter disclosed herein is to be interpreted as also being
disclosed in combination with each amount/value or range of
amounts/values disclosed for any other component(s), compounds(s),
substituent(s), or parameter(s) disclosed herein and that any
combination of amounts/values or ranges of amounts/values for two
or more component(s), compounds(s), substituent(s), or parameters
disclosed herein are thus also disclosed in combination with each
other for the purposes of this description.
[0061] It is further understood that each lower limit of each range
disclosed herein is to be interpreted as disclosed in combination
with each upper limit of each range disclosed herein for the same
component, compounds, substituent, or parameter. Thus, a disclosure
of two ranges is to be interpreted as a disclosure of four ranges
derived by combining each lower limit of each range with each upper
limit of each range. A disclosure of three ranges is to be
interpreted as a disclosure of nine ranges derived by combining
each lower limit of each range with each upper limit of each range,
etc. Furthermore, specific amounts/values of a component, compound,
substituent, or parameter disclosed in the description or an
example is to be interpreted as a disclosure of either a lower or
an upper limit of a range and thus can be combined with any other
lower or upper limit of a range or specific amount/value for the
same component, compound, substituent, or parameter disclosed
elsewhere in the application to form a range for that component,
compound, substituent, or parameter.
[0062] Lubricants, combinations of components, or individual
components of the present description may be suitable for use for
lubrication of the timing chain in various types of internal
combustion engines. An internal combustion engine may be a gasoline
fueled engine, a mixed gasoline/biofuel fueled engine, an alcohol
fueled engine, or a mixed gasoline/alcohol fueled engine. A
gasoline engine may be a spark-ignited engine. An internal
combustion engine may also be used in combination with an
electrical or battery source of power. An engine so configured is
commonly known as a hybrid engine. The internal combustion engine
may be a 2-stroke, 4-stroke, or rotary engine. Suitable internal
combustion engines include marine engines, aviation piston engines,
and motorcycle, automobile, locomotive, and truck engines.
[0063] The internal combustion engine may contain components of one
or more of an aluminum-alloy, lead, tin, copper, cast iron,
magnesium, ceramics, stainless steel, composites, and/or mixtures
thereof. The components may be coated, for example, with a
diamond-like carbon coating, a lubrited coating, a
phosphorus-containing coating, molybdenum-containing coating, a
graphite coating, a nano-particle-containing coating, and/or
mixtures thereof. The aluminum-alloy may include aluminum
silicates, aluminum oxides, or other ceramic materials. In one
embodiment the aluminum-alloy is an aluminum-silicate surface. As
used herein, the term "aluminum alloy" is intended to be synonymous
with "aluminum composite" and to describe a component or surface
comprising aluminum and another component intermixed or reacted on
a microscopic or nearly microscopic level, regardless of the
detailed structure thereof. This would include any conventional
alloys with metals other than aluminum as well as composite or
alloy-like structures with non-metallic elements or compounds such
with ceramic-like materials.
[0064] The lubricant composition of the present disclosure may be
suitable for any engine irrespective of the sulfur, phosphorus, or
sulfated ash (ASTM D-874) content. The sulfur content of the
lubricating oil may be about 1 wt. % or less, or about 0.8 wt. % or
less, or about 0.5 wt. % or less, or about 0.3 wt. % or less. In
one embodiment the sulfur content may be in the range of about
0.001 wt. % to about 0.5 wt. %, or about 0.01 wt. % to about 0.3
wt. %. The phosphorus content may be about 0.5 wt. % or less, or
about 0.1 wt. % or less, or about 0.094 wt. % or less, or about
0.001 wt. % to about 0.5 wt. %, or about 0.01 wt. % to about 0.1
wt. %.
[0065] In one embodiment the phosphorus content of the lubricant
compositions of the present disclosure may be about 100 ppm to
about 1000 ppm, or about 325 ppm to about 950 ppm. The total
sulfated ash content may be about 2 wt. % or less, or about 1.5 wt.
% or less, or about 1.2 wt. % or less. In one embodiment the
sulfated ash content may be about 0.05 wt. % to about 1.5 wt. %, or
about 0.1 wt. % or about 0.2 wt. % to about 1.15 wt. %. In another
embodiment, the sulfur content may be about 0.4 wt. % or less, the
phosphorus content may be about 0.08 wt. % or less, and the
sulfated ash is about 1.2 wt. % or less. In yet another embodiment
the sulfur content may be about 0.3 wt. % or less, the phosphorus
content is about 0.05 wt. % or less, and the sulfated ash may be
about 1.15 wt. % or less.
[0066] In one embodiment the timing chain lubricating composition
is also suitable for use as an engine oil, for example, for
lubrication of the crankcase of an engine. In other embodiments,
the lubricating composition may have (i) a sulfur content of about
0.5 wt. % or less, (ii) a phosphorus content of about 0.1 wt. % or
less, and (iii) a sulfated ash content of about 1.5 wt. % or
less.
[0067] In some embodiments, the lubricating composition is not
suitable for a 2-stroke or a 4-stroke marine diesel internal
combustion engine for one or more reasons, including but not
limited to, the high sulfur content of fuel used in powering a
marine engine and the high TBN required for a marine-suitable
engine oil (e.g., above about 40 TBN in a marine-suitable engine
oil).
[0068] In some embodiments, the lubricating composition is suitable
for use with engines powered by low sulfur fuels, such as fuels
containing about 1 to about 5% sulfur. Highway vehicle fuels
contain about 15 ppm sulfur (or about 0.0015% sulfur).
[0069] Lubricants of the present description may be suitable to
meet one or more industry specification requirements such as ILSAC
GF-3, GF-4, GF-5, GF-6, PC-11, CI-4, CJ-4, ACEA A1/B1, A2/B2,
A3/B3, A5/B5, C1, C2, C3, C4, E4/E6/E7/E9, Euro 5/6, Jaso DL-1, Low
SAPS, Mid SAPS, or original equipment manufacturer specifications
such as Dexos.TM. 1, Dexos.TM. 2, MB-Approval 229.51/229.31, VW
502.00, 503.00/503.01, 504.00, 505.00, 506.00/506.01, 507.00, BMW
Longlife-04, Porsche C30, Peugeot Citroen Automobiles B71 2290,
Ford WSS-M2C153-H, WSS-M2C930-A, WSS-M2C945-A, WSS-M2C913A,
WSS-M2C913-B, WSS-M2C913-C, GM 6094-M, Chrysler MS-6395, or any
past or future PCMO or HDD specifications not mentioned herein. In
some embodiments for passenger car motor oil (PCMO) applications,
the amount of phosphorus in the finished fluid is 1000 ppm or less
or 900 ppm or less or 800 ppm or less.
[0070] Other hardware may not be suitable for use with the
disclosed lubricant. A "functional fluid" is a term which
encompasses a variety of fluids including but not limited to
tractor hydraulic fluids, power transmission fluids including
automatic transmission fluids, continuously variable transmission
fluids and manual transmission fluids, hydraulic fluids, including
tractor hydraulic fluids, some gear oils, power steering fluids,
fluids used in wind turbines, compressors, some industrial fluids,
and fluids related to power train components. It should be noted
that within each class of these fluids such as, for example,
automatic transmission fluids, there are a variety of different
types of fluids due to the various transmissions having different
designs which have led to the need for fluids of markedly different
functional characteristics. This is contrasted by the term
"lubricating fluid" which is not used to generate or transfer
power.
[0071] When the functional fluid is an automatic transmission
fluid, the automatic transmission fluids must have enough friction
for the clutch plates to transfer power. However, the friction
coefficient of fluids has a tendency to decline due to the
temperature effects as the fluid heats up during operation. It is
important that the tractor hydraulic fluid or automatic
transmission fluid maintain its high friction coefficient at
elevated temperatures, otherwise brake systems or automatic
transmissions may fail. This is not a function of the lubricating
oil of the present invention.
[0072] Tractor fluids, and for example Super Tractor Universal Oils
(STUOs) or Universal Tractor Transmission Oils (UTTOs), may combine
the performance of engine oils with transmissions, differentials,
final-drive planetary gears, wet-brakes, and hydraulic performance.
While many of the additives used to formulate a UTTO or a STUO
fluid are similar in functionality, they may have deleterious
effect if not incorporated properly. For example, some anti-wear
and extreme pressure additives can be extremely corrosive to the
copper components in hydraulic pumps. Detergents and dispersants
used for gasoline or diesel engine performance may be detrimental
to wet brake performance. Friction modifiers specific to quiet wet
brake noise, may lack the thermal stability required for oil
performance. Each of these fluids, whether functional, tractor, or
lubricating, are designed to meet specific and stringent
manufacturer requirements.
[0073] The present disclosure provides, in one embodiment, a method
for reducing timing chain stretch of a timing chain in an engine
comprising a step of lubricating said timing chain with a
lubricating oil composition including:
[0074] a major amount of a base oil; and
[0075] a minor amount of an additive package including: [0076] a)
at least one overbased calcium phenate detergent having a total
base number of at least 150 mg KOH/g, measured by the method of
ASTM D-2896; [0077] b) at least one calcium sulfonate detergent;
and [0078] c) at least one magnesium-containing detergent.
[0079] Embodiments of the present disclosure may provide
improvements in the following characteristics: timing chain stretch
or elongation, sludge and/or soot dispersability, and friction
reduction, as well as air entrainment, alcohol fuel compatibility,
antioxidancy, antiwear performance, biofuel compatibility, foam
reducing properties, fuel economy, deposit reduction, pre-ignition
prevention, rust inhibition, and water tolerance.
[0080] Lubricating oils suitable for use in the methods of the
present disclosure may be formulated by the addition of additives,
as described in detail below, to an appropriate base oil
formulation. The additives may be combined with a base oil in the
form of one or more additive packages (or concentrates) or,
alternatively, may be combined individually with a base oil. The
fully formulated lubricating oil may exhibit improved performance
properties, based on the additives added and their respective
proportions. Details of the compositions of the lubricating oils
useful in the methods of the present invention are set forth
below.
Base Oil
[0081] The base oil used in the lubricating oil compositions herein
may be selected from any of the base oils in Groups I-V as
specified in the American Petroleum Institute (API) Base Oil
Interchangeability Guidelines. The five base oil groups are as
follows:
Base Oil Groups
TABLE-US-00001 [0082] Base oil Saturates Viscosity Category Sulfur
(%) (%) Index Group I >0.03 and/or <90 80 to 120 Group II
.ltoreq.0.03 and .gtoreq.90 80 to 120 Group III .ltoreq.0.03 and
.gtoreq.90 .gtoreq.120 Group IV All polyalphaolefins (PAOs) Group V
All others not included in Groups I, II, III, or IV
[0083] Groups I, II, and III are mineral oil process stocks. Group
IV base oils contain true synthetic molecular species, which are
produced by polymerization of olefinically unsaturated
hydrocarbons. Many Group V base oils are also true synthetic
products and may include diesters, polyol esters, polyalkylene
glycols, alkylated aromatics, polyphosphate esters, polyvinyl
ethers, and/or polyphenyl ethers, and the like, but may also be
naturally occurring oils, such as vegetable oils. It should be
noted that although Group III base oils are derived from mineral
oil, the rigorous processing that these fluids undergo causes their
physical properties to be very similar to some true synthetics,
such as PAOs. Therefore, oils derived from Group III base oils may
be referred to as synthetic fluids in the industry.
[0084] The base oil used in the lubricating oil composition may be
a mineral oil, animal oil, vegetable oil, synthetic oil, or
mixtures thereof. Suitable oils may be derived from hydrocracking,
hydrogenation, hydrofinishing, unrefined, refined, and re-refined
oils, and mixtures thereof.
[0085] Unrefined oils are those derived from a natural, mineral, or
synthetic source without or with little further purification
treatment. Refined oils are similar to the unrefined oils except
that they have been treated in one or more purification steps,
which may result in the improvement of one or more properties.
Examples of suitable purification techniques are solvent
extraction, secondary distillation, acid or base extraction,
filtration, percolation, and the like. Oils refined to the quality
of an edible may or may not be useful. Edible oils may also be
called white oils. In some embodiments, lubricant compositions are
free of edible or white oils.
[0086] Re-refined oils are also known as reclaimed or reprocessed
oils. These oils are obtained similarly to refined oils using the
same or similar processes. Often these oils are additionally
processed by techniques directed to removal of spent additives and
oil breakdown products.
[0087] Mineral oils may include oils obtained by drilling or from
plants and animals or any mixtures thereof. For example such oils
may include, but are not limited to, castor oil, lard oil, olive
oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as
mineral lubricating oils, such as liquid petroleum oils and
solvent-treated or acid-treated mineral lubricating oils of the
paraffinic, naphthenic or mixed paraffinic-naphthenic types. Such
oils may be partially or fully hydrogenated, if desired. Oils
derived from coal or shale may also be useful.
[0088] Useful synthetic lubricating oils may include hydrocarbon
oils such as polymerized, oligomerized, or interpolymerized olefins
(e.g., polybutylenes, polypropylenes, propyleneisobutylene
copolymers); poly(l-hexenes), poly(l-octenes), trimers or oligomers
of 1-decene, e.g., poly(l-decenes), such materials being often
referred to as .alpha.-olefins, and mixtures thereof;
alkyl-benzenes (e.g. dodecylbenzenes, tetradecylbenzenes,
dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g.,
biphenyls, terphenyls, alkylated polyphenyls); diphenyl alkanes,
alkylated diphenyl alkanes, alkylated diphenyl ethers and alkylated
diphenyl sulfides and the derivatives, analogs and homologs thereof
or mixtures thereof. Polyalphaolefins are typically hydrogenated
materials.
[0089] Other synthetic lubricating oils include polyol esters,
diesters, liquid esters of phosphorus-containing acids (e.g.,
tricresyl phosphate, trioctyl phosphate, and the diethyl ester of
decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic
oils may be produced by Fischer-Tropsch reactions and typically may
be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one
embodiment oils may be prepared by a Fischer-Tropsch gas-to-liquid
synthetic procedure as well as other gas-to-liquid oils.
[0090] The amount of the oil of lubricating viscosity present may
be the balance remaining after subtracting from 100 wt. % the sum
of the amount of the performance additives inclusive of viscosity
index improver(s) and/or pour point depressant(s) and/or other top
treat additives. For example, the oil of lubricating viscosity that
may be present in a finished fluid may be a major amount, such as
greater than about 50 wt. %, greater than about 60 wt. %, greater
than about 70 wt. %, greater than about 80 wt. %, greater than
about 85 wt. %, or greater than about 90 wt. %.
[0091] In certain embodiments, a particular selection of the base
oil may provide advantageous results in reducing chain stretch or
elongation. For example, in some embodiments, it may be desirable
to select a base oil with a viscosity grade of either 0W-X or 5W-X.
In certain embodiments, advantages may be attained by selecting a
base oil with an SAE Viscosity grade of 0W-20 or 5W-20 or
5W-40.
Detergents
[0092] The lubricant composition of the disclosure for use in the
method of reducing timing chain stretch contains at least one
overbased calcium phenate detergent having a total base number of
at least 150 mg KOH/g, measured by the method of ASTM D-2896; at
least one calcium sulfonate detergent; and at least one
magnesium-containing detergent.
[0093] Overbased calcium phenate detergents are typically formed by
overbasing calcium alkylphenates and/or calcium alkenylphenates
where the aromatic ring is substituted with one or more alkyl or
alkenyl groups (usually 1 to 2) that render the finished product
soluble or at least stably dispersible in oil. The alkyl or alkenyl
substituents on the aromatic ring typically contain at least about
6 carbon atoms and may contain as many as 500 or more carbon atoms.
Preferred substituents are derived from alpha-olefins such as are
formed by wax cracking or chain growth of ethylene on aluminum
alkyls such as triethyl aluminum, or from olefin oligomers such as
olefin dimers, trimers, tetramers and/or pentamers. However higher
polymers such as polypropenes, polyisobutenes, polyamylenes, and
copolymers such as copolymers of ethylene and propylene, etc., are
also useful as source materials for forming the substituted phenols
from which the calcium phenate is produced. In most cases the
phenate will have an alkyl or alkenyl substituent having in the
range of about 6 to about 50 carbon atoms. The phenolic ring may
also additionally contain short chain substituents such as methyl,
ethyl, isopropyl, butyl, etc. substituents. Likewise, the phenate
may be a derivative of a polyhydroxy aromatic compound, such as
catechol, resorcinol, or hydroquinone.
[0094] The overbased sulfurized calcium phenates can be formed from
the substituted phenols described above by reacting the substituted
phenol with sulfur monochloride, sulfur dichloride or elemental
sulfur. The phenol:sulfur compound molar ratio is usually in the
range of about 1:0.5 to about 1:1.5 or more. Reaction temperatures
in the range of about 60 to about 200.degree. C. are usually
employed. Generally the phenol:sulfur group molar ratio in the
sulfurized phenate is in the range of about 2:1 to about 1:2.
[0095] The overbased calcium phenate detergents have a total base
number of at least 150 mg KOH/g, at least about 225 mg KOH/g, at
least 225 mg KOH/g to about 400 mg KOH/g, at least about 225 mg
KOH/g to about 350 mg KOH/g or about 230 to about 350 mg KOH/g, all
as measured by the method of ASTM D-2896. When such detergent
compositions are formed in an inert diluent, e.g. a process oil,
usually a mineral oil, the total base number reflects the basicity
of the overall composition including diluent, and any other
materials (e.g., promoter, etc.) that may be contained in the
detergent composition.
[0096] The at least one calcium sulfonate detergent can be derived
from suitable aliphatic, cycloaliphatic, aromatic or heterocyclic
sulfonic acids and/or the salts thereof. In general such acids can
be represented by the formulas R(SO.sub.3H).sub.n and
(R').sub.xT(SO.sub.3H).sub.y where R is an aliphatic or
aliphatic-substituted cycloaliphatic group free from acetylenic
unsaturation and having up to about 60 carbon atoms; n is at least
one, and is generally in the range of 1 to 3; R' is an aliphatic
group free from acetylenic unsaturation (typically alkyl or
alkenyl) and having about 4 to about 60 carbon atoms; T is a cyclic
nucleus which may be derived from an aromatic hydrocarbon such as
benzene, toluene, xylene, naphthalene, anthracene, biphenyl, etc.,
or from a heterocyclic compound such as pyridine, indole,
isoindole, etc. Ordinarily T is an aromatic hydrocarbon nucleus
such as benzene or naphthalene; and x and y have an average value
of about 1 to 4 per molecule, most often an average of about 1.
Examples of such acids are petroleum sulfonic acids, paraffin wax
sulfonic acids, wax-substituted cyclohexyl sulfonic acids,
cetylcyclopentyl sulfonic acids, wax-substituted aromatic sulfonic
acids, mahogany sulfonic acids, tetraisobutylene sulfonic acids,
tetraamylene sulfonic acids, and the like. Most preferably, the
overbased calcium salts are formed from alkylaryl sulfonic acids,
such as alkylbenzene sulfonic acids. The alkyl group or groups
present on the aromatic ring typically each contain from about 8 to
about 40 carbon atoms. Suitable calcium sulfonates include
overbased calcium sulfonate detergents having total base numbers of
at least about 225 mg KOH/g of the overbased composition are
available as articles of commerce from a number of suppliers. One
such material is HiTEC.RTM. 611 additive (Ethyl Petroleum
Additives, Inc.) which has a nominal TBN of about 300 mg KOH/gram
of the composition.
[0097] In each of the foregoing embodiments, the calcium sulfonate
detergent is overbased and has a total base number of at least 225
mg KOH/g, or about 225 to about 500 mg KOH/g, or about 290 to about
500 mg KOH/g, or about 250 mg KOH/g to about 400 mg KOH/g or about
300 mg KOH/g to about 400 mg KOH/g measured by the method of ASTM
D-2896.
[0098] The additive package and lubricant composition of the
present disclosure includes at least one magnesium-containing
detergents. Suitable magnesium-containing detergents include
overbased magnesium-containing detergents, such as overbased
magnesium phenates, overbased magnesium sulfur containing phenates,
overbased magnesium sulfonates, overbased magnesium calixarates,
overbased magnesium salixarates, overbased magnesium salicylates,
overbased magnesium carboxylic acids, overbased magnesium
phosphorus acids, overbased magnesium mono- and/or
di-thiophosphoric acids, overbased magnesium alkyl phenols,
overbased magnesium sulfur coupled alkyl phenol compounds, or
overbased magnesium methylene bridged phenols.
[0099] The preferred overbased magnesium salts are overbased
magnesium alkylbenzene sulfonate detergent compositions having a
total base number of at least about 300 milligrams of KOH per gram
thereof, or at least about 300 mg KOH/g, or a total base number in
the range of about 350 to about 500 milligrams of KOH per gram
thereof. The lubricating oil composition may contain from about 50
ppm to about 1650 ppm, or from about 80 ppm to about 1250 ppm, or
from about 250 ppm to about 1100 ppm of magnesium provided by the
at least one magnesium-containing detergent, based on a total
weight of the lubricating oil composition.
[0100] The lubricating oil composition may contain from about 50
ppm to about 1650 ppm, or from about 80 ppm to about 1250 ppm, or
from about 100 ppm to about 900 ppm of calcium provided by the at
least one calcium sulfonate detergent, based on a total weight of
the lubricating oil composition. The lubricating oil composition
may contain from about 100 ppm to about 2000 ppm, or from about 250
ppm to about 1800 ppm, or from about 600 ppm to about 1500 ppm of
calcium provided by the at least one calcium phenate detergent,
based on a total weight of the lubricating oil composition. The
lubricating oil composition may contain from about 400 ppm to about
2200 ppm, or from about 500 ppm to about 1700 ppm, or from about
800 ppm to about 1600 ppm, or less than 1550 ppm of calcium
provided by all of the overbased calcium-containing detergents,
based on a total weight of the lubricating oil composition. Also,
in some embodiments the total amount of calcium in the lubricating
oil composition from all sources may be from about 1000 ppm to less
than about 3090 ppm, or about 1200 ppm to about 2000 ppm, or about
1300 ppm to about 1600 ppm. In some embodiments, the overbased
calcium detergent comprises from about 0.9 wt. % to about 10 wt. %,
or from about 1 wt. % to about 5 wt. %, or from about 1 wt. % to
about 2 wt. % of the lubricating oil composition.
[0101] The lubricating oil composition has a weight ratio of total
calcium from the at least one calcium sulfonate detergent to total
calcium and magnesium in the lubricating oil composition from about
0.06 to less than about 0.45 or from about 0.06 to about 0.4, or
from about 0.06 to about 0.35.
[0102] The detergent component may optionally also include one or
more other overbased calcium salts of at least one acidic organic
compound. These include overbased calcium calixarates, overbased
calcium salixarates, overbased calcium salicylates, overbased
calcium carboxylic acids, overbased calcium phosphorus acids,
overbased calcium mono- and/or di-thiophosphoric acids, overbased
calcium alkyl phenols, overbased calcium sulfur coupled alkyl
phenol compounds, and overbased calcium methylene bridged
phenols.
[0103] The terminology "overbased" relates to metal salts, such as
metal salts of sulfonates, carboxylates, and phenates, wherein the
amount of metal present exceeds the stoichiometric amount. Such
salts may have a conversion level in excess of 100% (i.e., they may
comprise more than 100% of the theoretical amount of metal needed
to convert the acid to its "normal," "neutral" salt). The
expression "metal ratio," often abbreviated as MR, is used to
designate the ratio of total chemical equivalents of metal in the
overbased salt to chemical equivalents of the metal in a neutral
salt according to known chemical reactivity and stoichiometry. In a
normal or neutral salt, the metal ratio is one and in an overbased
salt, MR, is greater than one. Salts with an MR greater than one
are commonly referred to as overbased, hyperbased, or superbased
salts and may be salts of organic sulfur acids, carboxylic acids,
or phenols.
[0104] The actual stoichiometric excess of metal in the overbased
salt can vary considerably, for example, from about 0.1 equivalent
to about 50 or more equivalents depending on the materials used,
the reactions utilized, and the process conditions employed.
Generally speaking, the overbased calcium salts useful in the
lubricating oil compositions contain from about 1.1 to about 40 or
more equivalents of calcium, more preferably from about 1.5 to
about 30 and most preferably from about 2 to about 25 equivalents
of calcium for each equivalent of material which is overbased.
Similarly, the overbased magnesium salts useful in the lubricating
oil compositions contain from about 1.1 to about 40 or more
equivalents of magnesium, more preferably from about 1.5 to about
30 and most preferably from about 2 to about 25 equivalents of
magnesium for each equivalent of material which is overbased.
[0105] Suitable overbased carboxylic acids which can be used in the
lubricating oil composition include overbased aliphatic carboxylic
acids, overbased cycloaliphatic carboxylic acids, overbased
aromatic carboxylic acids, and overbased heterocyclic carboxylic
acids. Such acids can be monocarboxylic or polycarboxylic acids,
and the principal requirement is that the acid have sufficient
chain length to be soluble or at least stably dispersible in
lubricating oil. Thus the acids generally contain from about 8 to
about 50, and preferably from about 12 to about 30, carbon atoms,
although certain acids such as alkyl- or alkenyl-substituted
succinic acids can have an average of up to 500 or more carbon
atoms per molecule. The acids are usually free of acetylenic
unsaturation. Examples include linolenic acid, capric acid,
linoleic acid, oleic acid, stearic acid, lauric acid, ricinoleic
acid, undecylic acid, palmitoleic acid, 2-ethylhexanoic acid,
myristic acid, isostearic acid, behenic acid, pelargonic acid,
propylene tetramer-substituted succinic acid, isobutene
trimer-substituted succinic acid, octylcyclopentane carboxylic
acid, stearyl-octahydroindenecarboxylic acid, tall oil acids, rosin
acids, polybutenyl succinic acids derived from polybutene having a
GPC number average molecular weight in the range of 200 to 1500,
acids formed by oxidation of wax, and like acids.
[0106] The overbased detergents may have a metal to substrate ratio
of from 1.1:1, or from 2:1, or from 4:1, or from 5:1, or from 7:1,
or from 10:1.
[0107] The lubricant composition of the disclosure may also
optionally include one or more neutral or low based detergents or
mixtures thereof. Low based detergents are detergents with a TBN of
greater than 0 up to less than 150 mg KOH/gram of composition. The
one or more additional neutral or low based detergents may be
selected from a neutral or low based calcium sulfonate detergent, a
neutral or low based calcium salicylate detergent or any
combination thereof.
[0108] Suitable low based calcium alkylbenzene sulfonate detergent
compositions, most preferably low based calcium propylene-derived
alkylaryl sulfonates are formed by preparing an alkali or alkaline
earth metal salt of an alkylbenzene sulfonic acid and if desired,
subjecting the salt in the presence of a small excess of an alkali
or alkaline earth metal base such as an oxide, hydroxide or
alcoholate to the action of an acidic material such as carbon
dioxide so that a small amount of overbasing occurs. This
controlled overbasing can be conducted using the same materials in
much the same way as the overbasing described above, except of
course the amount of metal base is such that the desired total base
number of the resultant composition is achieved. Suitable low base
materials of the foregoing types are available as articles of
commerce. HiTEC.RTM. 614 additive (Ethyl Petroleum Additives, Inc.)
is a good example of a commercially-available calcium alkylbenzene
sulfonate. Low-base calcium sulfurized alkylphenates are also
suitable components in the compositions of this disclosure.
[0109] The total amount of detergent that may be present in the
lubricating oil composition may be from about 1 wt. % to about 15
wt. %, or from about 1 wt. % to about 10 wt. %, or about 1 wt. % to
about 8 wt. %, or about 1 wt. % to about 4 wt. %, or greater than
about 4 wt. % to about 8 wt. %, based on a total weight of the
lubricating oil composition.
Antiwear Agents
[0110] The lubricating oil compositions of the present disclosure
may optionally contain one or more metal dialkyl dithiophosphate
antiwear agents. The metal in the dialkyl dithiophosphate salts may
be an alkali metal, alkaline earth metal, aluminum, lead, tin,
molybdenum, manganese, nickel, copper, titanium, or zinc. A
particularly useful metal dialkyl dithiophosphate salt may be zinc
dialkyl dithiophosphate.
[0111] Zinc dialkyl dithiophosphates (ZDDP) are oil soluble salts
of dialkyl dithiophosphoric acids and may be represented by the
following formula:
##STR00001##
wherein R.sub.5 and R.sub.6 may be the same or different alkyl
and/or cycloalkyl groups containing from 1 to 18 carbon atoms, or 2
to 12 carbon atoms, or 2 to 8 carbon atoms. Thus, the alkyl and/or
cycloalkyl groups may be, for example, ethyl, n-propyl, i-propyl,
n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n-octyl,
decyl, dodecyl, octadecyl, 2-ethylhexyl, cyclohexyl,
methylcyclopentyl, propenyl, or butenyl.
[0112] The dialkyl dithiophosphate metal salts may be prepared in
accordance with known techniques by first forming a dialkyl
dithiophosphoric acid (DDPA), usually by reaction of one or more
alcohols and then neutralizing the formed DDPA with a metal
compound. To make the metal salt, any basic or neutral metal
compound could be used but the oxides, hydroxides, and carbonates
are most generally employed. The zinc dialkyl dithiophosphates of
component (i) may be made by a process such as the process
generally described in U.S. Pat. No. 7,368,596.
[0113] In some embodiments, the at least one metal dialkyl
dithiophosphate salt may be present in the lubricating oil in an
amount sufficient to provide from about 100 to about 1200 ppm
phosphorus, or from about 200 to about 1100 ppm phosphorus, or from
about 300 to about 1000 ppm phosphorus, or from about 400 to about
1000 ppm phosphorus, or from about 550 to about 980 ppm phosphorus.
In some embodiments, the at least one metal dialkyl dithiophosphate
salt may be present in the lubricating oil in amounts of from about
0 wt. % to about 6.0 wt. %, or from about 0.1 wt. % to about 6.0
wt. %, or from about 0.1 wt. % to about 4.0 wt. %, based on a total
weight of the lubricating oil composition.
[0114] In some embodiments, the metal dialkyl dithiophosphate salt
may be zinc dialkyl dithiophosphate (ZDDP). In some embodiments,
the additive package may comprise two or more metal dialkyl
dithiophosphate salts and one, two, or all is ZDDP. The zinc
dialkyl dithiophosphate may deliver from about 600 ppm to about
1300 ppm, or from about 750 ppm to about 1200 ppm, or from about
800 ppm to about 1100 ppm of zinc to the lubricating oil
composition.
[0115] The lubricating oil compositions of the present disclosure
may also optionally contain one or more additional antiwear agents.
Examples of suitable additional antiwear agents include, but are
not limited to, a metal thiophosphate; a phosphoric acid ester or
salt thereof; a phosphate ester(s); a phosphite; a
phosphorus-containing carboxylic ester, ether, or amide; a
sulfurized olefin; thiocarbamate-containing compounds including,
thiocarbamate esters, alkylene-coupled thiocarbamates, and
bis(S-alkyldithiocarbamyl)disulfides; and mixtures thereof. The
phosphorus containing antiwear agents are more fully described in
European Patent 612 839. The metal may be an alkali metal, alkaline
earth metal, aluminum, lead, tin, molybdenum, manganese, nickel,
copper, titanium, or zinc.
[0116] Further examples of suitable additional antiwear agents
include titanium compounds, tartrates, tartrimides, oil soluble
amine salts of phosphorus compounds, sulfurized olefins, phosphites
(such as dibutyl phosphite), phosphonates, thiocarbamate-containing
compounds, such as thiocarbamate esters, thiocarbamate amides,
thiocarbamic ethers, alkylene-coupled thiocarbamates, and
bis(S-alkyldithiocarbamyl) disulfides. The tartrate or tartrimide
may contain alkyl-ester groups, where the sum of carbon atoms on
the alkyl groups may be at least 8. The antiwear agent may in one
embodiment include a citrate.
[0117] The additional antiwear agent(s) may be used in amount of
from about 0.0-1.0 wt. % or from about 0.0 to about 0.8 wt. %,
based on a total weight of the lubricating oil composition. The
total amount of antiwear agent(s) present in the lubrication oil
composition may range from about 0 wt. % to about 7 wt. %, or about
0.01 wt. % to about 5 wt. %, or about 0.1 wt. % to about 4.8 wt. %,
based on the total weight of the lubricating oil composition.
Dispersants
[0118] The lubricant composition may optionally further comprise
one or more dispersants or mixtures thereof. Dispersants are often
known as ashless-type dispersants because, prior to mixing in a
lubricating oil composition, they do not contain ash-forming metals
and they do not normally contribute any ash when added to a
lubricant. Ashless-type dispersants are characterized by a polar
group attached to a relatively high molecular or weight hydrocarbon
chain. Typical ashless dispersants include N-substituted long chain
alkenyl succinimides. Examples of N-substituted long chain alkenyl
succinimides include polyisobutylene succinimide with number
average molecular weight of the polyisobutylene substituent in a
range of about 350 to about 5000, or about 500 to about 3000.
Succinimide dispersants and their preparation are disclosed, for
instance in U.S. Pat. No. 7,897,696 and U.S. Pat. No. 4,234,435.
Succinimide dispersants are typically an imide formed from a
polyamine, typically a poly(ethyleneamine).
[0119] In some embodiments the lubricant composition comprises at
least one polyisobutylene succinimide dispersant derived from
polyisobutylene with number average molecular weight in the range
about 350 to about 5000, or about 500 to about 3000. The
polyisobutylene succinimide may be used alone or in combination
with other dispersants.
[0120] In some embodiments, polyisobutylene (PIB), when included,
may have greater than 50 mol. %, greater than 60 mol. %, greater
than 70 mol. %, greater than 80 mol. %, or greater than 90 mol. %
content of terminal double bonds. Such a PIB is also referred to as
highly reactive PIB ("HR-PIB"). HR--PIB having a number average
molecular weight ranging from about 800 to about 5000 is suitable
for use in embodiments of the present disclosure. Conventional
non-highly reactive PIB typically has less than 50 mol. %, less
than 40 mol. %, less than 30 mol. %, less than 20 mol. %, or less
than 10 mol. % content of terminal double bonds.
[0121] An HR-PIB having a number average molecular weight ranging
from about 900 to about 3000 may be suitable. Such an HR-PIB is
commercially available, or can be synthesized by the polymerization
of isobutene in the presence of a non-chlorinated catalyst such as
boron trifluoride, as described in U.S. Pat. No. 4,152,499 and U.S.
Pat. No. 5,739,355. When used in the aforementioned thermal ene
reaction, HR-PIB may lead to higher conversion rates in the
reaction, as well as lower amounts of sediment formation, due to
increased reactivity.
[0122] In embodiments the lubricant composition comprises at least
one dispersant derived from polyisobutylene succinic anhydride. In
an embodiment, the dispersant may be derived from a polyalphaolefin
(PAO) succinic anhydride. In an embodiment, the dispersant may be
derived from olefin maleic anhydride copolymer. As an example, the
dispersant may be described as a poly-PIBSA. In an embodiment, the
dispersant may be derived from an anhydride which is grafted to an
ethylene-propylene copolymer.
[0123] One class of suitable dispersants may be Mannich bases.
Mannich bases are materials that are formed by the condensation of
a higher molecular weight, alkyl substituted phenol, a polyalkylene
polyamine, and an aldehyde such as formaldehyde. Mannich bases are
described in more detail in U.S. Pat. No. 3,634,515.
[0124] A suitable class of dispersants may be high molecular weight
esters or half ester amides.
[0125] The dispersants may also be post-treated by conventional
methods by reaction with any of a variety of agents. Among these
agents are boron, urea, thiourea, dimercaptothiadiazoles, carbon
disulfide, aldehydes, ketones, carboxylic acids,
hydrocarbon-substituted succinic anhydrides, maleic anhydride,
nitriles, epoxides, carbonates, cyclic carbonates, hindered
phenolic esters, and phosphorus compounds. U.S. Pat. No. 7,645,726;
U.S. Pat. No. 7,214,649; and U.S. Pat. No. 8,048,831 describe some
suitable post-treatment methods and post-treated products.
[0126] In one embodiment the lubricating oil composition may
include at least one borated dispersant, wherein the dispersant is
the reaction product of an olefin copolymer or a reaction product
of an olefin copolymer with succinic anhydride, and at least one
polyamine. The ratio of PIBSA:polyamine may be from 1:1 to 10:1,
preferably, 1:1 to 5:1, or 4:3 to 3:1 or 4:3 to 2:1. A particularly
useful dispersant contains a polyisobutenyl group of the PIBSA
having a number average molecular weight (Mn) in the range of from
about 500 to 5000 as determined by GPC using polystyrene as a
calibration reference and a (B) polyamine having a general formula
H.sub.2N(CH.sub.2)m-[NH(CH.sub.2).sub.m].sub.n--NH.sub.2, wherein m
is in the range from 2 to 4 and n is in the range of from 1 to
2.
[0127] In addition to boration, the dispersant may be post-treated
with an aromatic carboxylic acid, an aromatic polycarboxylic acid,
or an aromatic anhydride wherein all carboxylic acid or anhydride
group(s) are attached directly to an aromatic ring. Such
carboxyl-containing aromatic compounds may be selected from
1,8-naphthalic acid or anhydride and 1,2-naphthalenedicarboxylic
acid or anhydride, 2,3-naphthalenedicarboxylic acid or anhydride,
naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic
acid, phthalic anhydride, pyromellitic anhydride, 1,2,4-benzene
tricarboxylic acid anhydride, diphenic acid or anhydride,
2,3-pyridine dicarboxylic acid or anhydride, 3,4-pyridine
dicarboxylic acid or anhydride, 1,4,5,8-naphthalenetetracarboxylic
acid or anhydride, perylene-3,4,9,10-tetracarboxylic anhydride,
pyrene dicarboxylic acid or anhydride, and the like. The moles of
this post-treatment component reacted per mole of the polyamine may
range from about 0.1:1 to about 2:1. A typical molar ratio of this
post-treatment component to polyamine in the reaction mixture may
range from about 0.2:1 to about 2:1. Another molar ratio of this
post-treatment component to the polyamine that may be used may
range from 0.25:1 to about 1.5:1. This post-treatment component may
be reacted with the other components at a temperature ranging from
about 140.degree. to about 180.degree. C.
[0128] Alternatively, or in addition to the post-treatment
described in the previous paragraph, the borated dispersant may be
post-treated with a non-aromatic dicarboxylic acid or anhydride.
The non-aromatic dicarboxylic acid or anhydride of may have a
number average molecular weight of less than 500. Suitable
carboxylic acids or anhydrides thereof may include, but are not
limited to acetic acid or anhydride, oxalic acid and anhydride,
malonic acid and anhydride, succinic acid and anhydride, alkenyl
succinic acid and anhydride, glutaric acid and anhydride, adipic
acid and anhydride, pimelic acid and anhydride, suberic acid and
anhydride, azelaic acid and anhydride, sebacic acid and anhydride,
maleic acid and anhydride, fumaric acid and anhydride, tartaric
acid and anhydride, glycolic acid and anhydride,
1,2,3,6-tetrahydronaphthalic acid and anhydride, and the like.
[0129] The non-aromatic carboxylic acid or anhydride is reacted at
a molar ratio with the polyamine ranging from about 0.1 to about
2.5 moles per mole of polyamine Typically, the amount of
non-aromatic carboxylic acid or anhydride used will be relative to
the number of secondary amino groups in the polyamine. Accordingly,
from about 0.2 to about 2.0 moles of the non-aromatic carboxylic
acid or anhydride per secondary amino group in Component B may be
reacted with the other components to provide the dispersant
according to embodiments of the disclosure. Another molar ratio of
the non-aromatic carboxylic acid or anhydride to polyamine that may
be used may range from 0.25:1 to about 1.5:1 moles of per mole of
polyamine. The non-aromatic carboxylic acid or anhydride may be
reacted with the other components at a temperature ranging from
about 140.degree. to about 180.degree. C.
[0130] The post-treatment step may be carried out upon completion
of the reaction of the olefin copolymer with succinic anhydride,
and at least one polyamine. In certain embodiments, the borated
dispersant is post treated with maleic anhydride and/or naphthalic
anhydride and, in these embodiments, the lubricating oil
composition may have a molybdenum content of at least 80 ppm or at
least 100 ppm or at least 150 ppm
[0131] The % actives of the alkenyl or alkyl succinic anhydride can
be determined using a chromatographic technique. This method is
described in column 5 and 6 in U.S. Pat. No. 5,334,321. The percent
conversion of the polyolefin is calculated from the % actives using
the equation in column 5 and 6 in U.S. Pat. No. 5,334,321.
[0132] In one embodiment, the borated dispersant may be derived
from a polyalphaolefin (PAO) succinic anhydride.
[0133] In one embodiment, the borated dispersant may be derived
from olefin maleic anhydride copolymer. As an example, the borated
dispersant may be described as a poly-PIBSA.
[0134] In an embodiment, the borated dispersant may be derived from
an anhydride which is grafted to an ethylene-propylene
copolymer.
[0135] One class of suitable dispersants for use as the borated
dispersant may be borated Mannich bases. Mannich bases are
materials that are formed by the condensation of a higher molecular
weight, alkyl substituted phenol, a polyalkylene polyamine, and an
aldehyde such as formaldehyde. Mannich bases are described in more
detail in U.S. Pat. No. 3,634,515.
[0136] A suitable class of borated dispersants may also include
high molecular weight esters or half ester amides.
[0137] The TBN of a suitable borated dispersant may be from about
10 to about 65 mg KOH/gram composition on an oil-free basis, which
is comparable to about 5 to about 30 mg KOH/gram composition TBN if
measured on a dispersant sample containing about 50% diluent
oil.
[0138] The dispersant, if present, can be used in an amount
sufficient to provide up to about 20 wt. %, based upon the total
weight of the lubricating oil composition. The amount of the
dispersant that can be used may be about 0.1 wt. % to about 15 wt.
%, or about 0.1 wt. % to about 10 wt. %, or about 0.5 wt. % to
about 10 wt. %, or about 1 wt. % to about 8 wt. %, or about 7 wt. %
to about 12 wt. %, based upon the total weight of the lubricating
oil composition. In an embodiment, the lubricating oil composition
utilizes a mixed dispersant system.
Molybdenum-Containing Component
[0139] The lubricating oil compositions of the present disclosure
may optionally contain one or more molybdenum-containing compounds.
An oil-soluble molybdenum compound may have the functional
performance of an antiwear agent, an antioxidant, a friction
modifier, or mixtures thereof. An oil-soluble molybdenum compound
may include molybdenum dithiocarbamates, molybdenum
dialkyldithiophosphates, molybdenum dithiophosphinates, amine salts
of molybdenum compounds, molybdenum xanthates, molybdenum
thioxanthates, molybdenum sulfides, molybdenum carboxylates,
molybdenum alkoxides, a trinuclear organo-molybdenum compound,
and/or mixtures thereof. The molybdenum sulfides include molybdenum
disulfide. The molybdenum disulfide may be in the form of a stable
dispersion. In one embodiment the oil-soluble molybdenum compound
may be selected from molybdenum dithiocarbamates, molybdenum
dialkyldithiophosphates, amine salts of molybdenum compounds, and
mixtures thereof. In one embodiment the oil-soluble molybdenum
compound may be a molybdenum dithiocarbamate.
[0140] Suitable examples of molybdenum compounds which may be used
include commercial materials sold under the trade names such as
Molyvan 822.TM., Molyvan.TM. A, Molyvan2000.TM. and Molyvan 855.TM.
from R. T. Vanderbilt Co., Ltd., and Sakura-Lube.TM. S-165, S-200,
S-300, 5-310G, S-525, S-600, S-700, and S-710 available from Adeka
Corporation, and mixtures thereof. Suitable molybdenum components
are described in U.S. Pat. No. 5,650,381; US RE 37,363 E1; US RE
38,929 E1; and US RE 40,595 E1.
[0141] Additionally, the molybdenum compound may be an acidic
molybdenum compound. Included are molybdic acid, ammonium
molybdate, sodium molybdate, potassium molybdate, and other
alkaline metal molybdates and other molybdenum salts, e.g.,
hydrogen sodium molybdate, MoOCl.sub.4, MoO.sub.2Br.sub.2,
Mo.sub.2O.sub.3Cl.sub.6, molybdenum trioxide or similar acidic
molybdenum compounds. Alternatively, the compositions can be
provided with molybdenum by molybdenum/sulfur complexes of basic
nitrogen compounds as described, for example, in U.S. Pat. Nos.
4,263,152; 4,285,822; 4,283,295; 4,272,387; 4,265,773; 4,261,843;
4,259,195 and 4,259,194; and WO 94/06897.
[0142] Another class of suitable organo-molybdenum compounds are
trinuclear molybdenum compounds, such as those of the formula
Mo.sub.3S.sub.kL.sub.nQ.sub.z and mixtures thereof, wherein S
represents sulfur, L represents independently selected ligands
having organo groups with a sufficient number of carbon atoms to
render the compound soluble or dispersible in the oil, n is from 1
to 4, k varies from 4 through 7, Q is selected from the group of
neutral electron donating compounds such as water, amines,
alcohols, phosphines, and ethers, and z ranges from 0 to 5 and
includes non-stoichiometric values. At least 21 total carbon atoms
may be present among all the ligands' organo groups, such as at
least 25, at least 30, or at least 35 carbon atoms. Additional
suitable molybdenum compounds are described in U.S. Pat. No.
6,723,685.
[0143] The oil-soluble molybdenum compound may be present in an
amount sufficient to provide about 80 ppm to about 2000 ppm, about
150 ppm to about 800 ppm, about 100 ppm to about 600 ppm, about 150
ppm to about 550 ppm of molybdenum to the lubricating oil
composition. In another embodiment, the molybdenum compound may be
present in an amount sufficient to provide about 100 ppm to about
1000 ppm, or about 150 ppm to about 600 ppm of molybdenum to the
lubricating oil composition. In another embodiment, the lubricating
oil composition may have less than about 200 ppm molybdenum, or
less than about 5 ppm, or about 10 ppm to about 150 ppm of
molybdenum.
[0144] In certain embodiments of the present disclosure, the
lubricating oil composition may contain at least 40 ppm of
molybdenum when the base oil has a viscosity grade of 0W-20, a
boron content of at least 100 ppm and a sulfur content of no
greater than 2100.
Antioxidants
[0145] The lubricating oil compositions herein also may optionally
contain one or more antioxidants. Antioxidant compounds are known
and include for example, phenates, phenate sulfides, sulfurized
olefins, phosphosulfurized terpenes, sulfurized esters, aromatic
amines, alkylated diphenylamines (e.g., nonyl diphenylamine,
di-nonyl diphenylamine, octyl diphenylamine, di-octyl
diphenylamine), phenyl-alpha-naphthylamines, alkylated
phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols,
hindered phenols, oil-soluble molybdenum compounds, macromolecular
antioxidants, or mixtures thereof. Antioxidant compounds may be
used alone or in combination.
[0146] The hindered phenol antioxidant may contain a secondary
butyl and/or a tertiary butyl group as a sterically hindering
group. The phenol group may be further substituted with a
hydrocarbyl group and/or a bridging group linking to a second
aromatic group. Examples of suitable hindered phenol antioxidants
include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol,
4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol
or 4-butyl-2,6-di-tert-butylphenol, or
4-dodecyl-2,6-di-tert-butylphenol. In one embodiment the hindered
phenol antioxidant may be an ester and may include, e.g.,
Irganox.TM. L-135 available from BASF or an addition product
derived from 2,6-di-tert-butylphenol and an alkyl acrylate, wherein
the alkyl group may contain about 1 to about 18, or about 2 to
about 12, or about 2 to about 8, or about 2 to about 6, or about 4
carbon atoms. Another commercially available hindered phenol
antioxidant may be an ester and may include Ethanox.TM. 4716
available from Albemarle Corporation.
[0147] Useful antioxidants may include diarylamines and high
molecular weight phenols. In an embodiment, the lubricating oil
composition may contain a mixture of a diarylamine and a high
molecular weight phenol, such that each antioxidant may be present
in an amount sufficient to provide up to about 5%, by weight, based
upon the final weight of the lubricating oil composition. In an
embodiment, the antioxidant may be a mixture of about 0.3 to about
1.5% diarylamine and about 0.4 to about 2.5% high molecular weight
phenol, by weight, based upon the final weight of the lubricating
oil composition.
[0148] Examples of suitable olefins that may be sulfurized to form
a sulfurized olefin include propylene, butylene, isobutylene,
polyisobutylene, pentene, hexene, heptene, octene, nonene, decene,
undecene, dodecene, tridecene, tetradecene, pentadecene,
hexadecene, heptadecene, octadecene, nonadecene, eicosene or
mixtures thereof. In one embodiment, hexadecene, heptadecene,
octadecene, nonadecene, eicosene or mixtures thereof and their
dimers, trimers and tetramers are especially useful olefins.
Alternatively, the olefin may be a Diels-Alder adduct of a diene
such as 1,3-butadiene and an unsaturated ester, such as,
butylacrylate.
[0149] Another class of sulfurized olefin includes sulfurized fatty
acids and their esters. The fatty acids are often obtained from
vegetable oil or animal oil and typically contain about 4 to about
22 carbon atoms. Examples of suitable fatty acids and their esters
include triglycerides, oleic acid, linoleic acid, palmitoleic acid
or mixtures thereof. Often, the fatty acids are obtained from lard
oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower
seed oil or mixtures thereof. Fatty acids and/or ester may be mixed
with olefins, such as .alpha.-olefins.
[0150] The one or more antioxidant(s) may be present in ranges
about 0 wt. % to about 5 wt. %, or about 0.01 wt. % to about 5 wt.
%, or about 0.1 wt. % to about 3 wt. %, or about 0.8 wt. % to about
2 wt. %, of the lubricating composition.
Extreme Pressure Agents
[0151] The lubricating oil compositions herein may also optionally
contain one or more extreme pressure agents. Extreme Pressure (EP)
agents that are soluble in the oil include sulfur- and
chlorosulfur-containing EP agents, chlorinated hydrocarbon EP
agents and phosphorus EP agents. Examples of such EP agents include
chlorinated wax; organic sulfides and polysulfides such as
dibenzyldisulfide, bis(chlorobenzyl) disulfide, dibutyl
tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized
alkylphenol, sulfurized dipentene, sulfurized terpene, and
sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons such
as the reaction product of phosphorus sulfide with turpentine or
methyl oleate; phosphorus esters such as the dihydrocarbyl and
trihydrocarbyl phosphites, e.g., dibutyl phosphite, diheptyl
phosphite, dicyclohexyl phosphite, pentylphenyl phosphite;
dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite
and polypropylene substituted phenyl phosphite; metal
thiocarbamates such as zinc dioctyldithiocarbamate and barium
heptylphenol diacid; amine salts of alkyl and dialkylphosphoric
acids, including, for example, the amine salt of the reaction
product of a dialkyldithiophosphoric acid with propylene oxide; and
mixtures thereof.
[0152] The extreme pressure agents may be present in amount of, for
example, from about 0 to 6.0 wt. % or from about 0.1 to 4.0 wt. %,
based on the total weight of the lubricating oil composition.
Friction Modifiers
[0153] The lubricating oil compositions herein may also optionally
contain one or more friction modifiers. Suitable friction modifiers
may comprise metal containing and metal-free friction modifiers and
may include, but are not limited to, imidazolines, amides, amines,
succinimides, alkoxylated amines, alkoxylated ether amines, amine
oxides, amidoamines, nitriles, betaines, quaternary amines, imines,
amine salts, amino guanidine, alkanolamides, phosphonates,
metal-containing compounds, glycerol esters, sulfurized fatty
compounds and olefins, sunflower oil other naturally occurring
plant or animal oils, dicarboxylic acid esters, esters or partial
esters of a polyol and one or more aliphatic or aromatic carboxylic
acids, and the like.
[0154] Suitable friction modifiers may contain hydrocarbyl groups
that are selected from straight chain, branched chain, or aromatic
hydrocarbyl groups or mixtures thereof, and may be saturated or
unsaturated. The hydrocarbyl groups may be composed of carbon and
hydrogen or hetero atoms such as sulfur or oxygen. The hydrocarbyl
groups may range from about 12 to about 25 carbon atoms. In some
embodiments the friction modifier may be a long chain fatty acid
ester. In another embodiment the long chain fatty acid ester may be
a mono-ester, or a di-ester, or a (tri)glyceride. The friction
modifier may be a long chain fatty amide, a long chain fatty ester,
a long chain fatty epoxide derivatives, or a long chain
imidazoline.
[0155] Other suitable friction modifiers may include organic,
ashless (metal-free), nitrogen-free organic friction modifiers.
Such friction modifiers may include esters formed by reacting
carboxylic acids and anhydrides with alkanols and generally include
a polar terminal group (e.g. carboxyl or hydroxyl) covalently
bonded to an oleophilic hydrocarbon chain. An example of an organic
ashless nitrogen-free friction modifier is known generally as
glycerol monooleate (GMO) which may contain mono-, di-, and
tri-esters of oleic acid. Other suitable friction modifiers are
described in U.S. Pat. No. 6,723,685.
[0156] Aminic friction modifiers may include amines or polyamines.
Such compounds can have hydrocarbyl groups that are linear, either
saturated or unsaturated, or a mixture thereof and may contain from
about 12 to about 25 carbon atoms. Further examples of suitable
friction modifiers include alkoxylated amines and alkoxylated ether
amines. Such compounds may have hydrocarbyl groups that are linear,
either saturated, unsaturated, or a mixture thereof. They may
contain from about 12 to about 25 carbon atoms. Examples include
ethoxylated amines and ethoxylated ether amines.
[0157] The amines and amides may be used as such or in the form of
an adduct or reaction product with a boron compound such as a boric
oxide, boron halide, metaborate, boric acid or a mono-, di- or
tri-alkyl borate. Other suitable friction modifiers are described
in U.S. Pat. No. 6,300,291.
[0158] A friction modifier may optionally be present in ranges such
as about 0 wt. % to about 5 wt. %, or about 0.01 wt. % to about 4
wt. %, or about 0.05 wt. % to about 2 wt. %.
Boron-Containing Compounds
[0159] The lubricating oil compositions herein may optionally
contain one or more boron-containing compounds other than the
borated dispersant discussed above.
[0160] Examples of boron-containing compounds include borate
esters, borated fatty amines, borated epoxides, and borated
detergents.
[0161] The additional boron-containing compound, if present, can be
used in an amount sufficient to provide up to about 8 wt. %, about
0.001 wt. % to about 7 wt. %, about 0.01 wt. % to about 5 wt. %, or
about 0.1 wt. % to about 3 wt. % of the lubricating composition. In
each of the foregoing embodiments, the lubricating oil compositions
herein may contain less than 200 ppm of boron, or 180 ppm or less,
or 150 ppm or less boron.
Titanium-Containing Compounds
[0162] Another class of optional additives that may be used in the
lubricating oil compositions of the invention is oil-soluble
titanium compounds. The oil-soluble titanium compounds may function
as antiwear agents, friction modifiers, antioxidants, deposit
control additives, or more than one of these functions. In an
embodiment the oil soluble titanium compound may be a titanium (IV)
alkoxide. The titanium alkoxide may be formed from a monohydric
alcohol, a polyol, or mixtures thereof. The monohydric alkoxides
may have 2 to 16, or 3 to 10 carbon atoms. In an embodiment, the
titanium alkoxide may be titanium (IV) isopropoxide. In an
embodiment, the titanium alkoxide may be titanium (IV)
2-ethylhexoxide. In an embodiment, the titanium compound may be the
alkoxide of a 1,2-diol or polyol. In an embodiment, the 1,2-diol
comprises a fatty acid mono-ester of glycerol, such as oleic acid.
In an embodiment, the oil soluble titanium compound may be a
titanium carboxylate. In an embodiment the titanium (IV)
carboxylate may be titanium neodecanoate.
[0163] In an embodiment the oil soluble titanium compound may be
present in the lubricating composition in an amount to provide from
zero to about 1500 ppm titanium by weight or about 10 ppm to 500
ppm titanium by weight or about 25 ppm to about 150 ppm titanium by
weight.
Viscosity Index Improvers
[0164] The lubricating oil compositions herein also may optionally
contain one or more viscosity index improvers. Suitable viscosity
index improvers may include polyolefins, olefin copolymers,
ethylene/propylene copolymers, polyisobutenes, hydrogenated
styrene-isoprene polymers, styrene/maleic ester copolymers,
hydrogenated styrene/butadiene copolymers, hydrogenated isoprene
polymers, alpha-olefin maleic anhydride copolymers,
polymethacrylates, polyacrylates, polyalkyl styrenes, hydrogenated
alkenyl aryl conjugated diene copolymers, or mixtures thereof.
Viscosity index improvers may include star polymers and suitable
examples are described in US Publication No. 20120101017A1.
[0165] The lubricating oil compositions herein also may optionally
contain one or more dispersant viscosity index improvers in
addition to a viscosity index improver or in lieu of a viscosity
index improver. Suitable viscosity index improvers may include
functionalized polyolefins, for example, ethylene-propylene
copolymers that have been functionalized with the reaction product
of an acylating agent (such as maleic anhydride) and an amine;
polymethacrylates functionalized with an amine, or esterified
maleic anhydride-styrene copolymers reacted with an amine.
[0166] The total amount of viscosity index improver and/or
dispersant viscosity index improver may be about 0 wt. % to about
20 wt. %, about 0.1 wt. % to about 15 wt. %, about 0.25 wt. % to
about 12 wt. %, or about 0.5 wt. % to about 10 wt. %, of the
lubricating composition.
Other Optional Additives
[0167] Other additives may be selected to perform one or more
functions required of a lubricating fluid. Further, one or more of
the mentioned additives may be multi-functional and provide
functions in addition to or other than the function prescribed
herein.
[0168] A lubricating composition according to the present
disclosure may optionally comprise other performance additives. The
other performance additives may be in addition to specified
additives of the present disclosure and/or may comprise one or more
of metal deactivators, ashless TBN boosters, corrosion inhibitors,
rust inhibitors, dispersant viscosity index improvers, foam
inhibitors, demulsifiers, emulsifiers, pour point depressants, seal
swelling agents and mixtures thereof. Typically, fully-formulated
lubricating oil will contain one or more of these performance
additives.
[0169] Suitable metal deactivators may include derivatives of
benzotriazoles (typically tolyltriazole), dimercaptothiadiazole
derivatives, 1,2,4-triazoles, benzimidazoles,
2-alkyldithiobenzimidazoles, or 2-alkyldithiobenzothiazoles; foam
inhibitors including copolymers of ethyl acrylate and
2-ethylhexylacrylate and optionally vinyl acetate; demulsifiers
including trialkyl phosphates, polyethylene glycols, polyethylene
oxides, polypropylene oxides and (ethylene oxide-propylene oxide)
polymers; pour point depressants including esters of maleic
anhydride-styrene, polymethacrylates, polyacrylates or
polyacrylamides.
[0170] Suitable foam inhibitors include silicon-based compounds,
such as siloxane.
[0171] Suitable pour point depressants may include a
polymethylmethacrylates or mixtures thereof. Pour point depressants
may be present in an amount sufficient to provide from about 0 wt.
% to about 5 wt. %, about 0.01 wt. % to about 1.5 wt. %, or about
0.02 wt. % to about 0.04 wt. % based upon the final weight of the
lubricating oil composition.
[0172] Suitable rust inhibitors may be a single compound or a
mixture of compounds having the property of inhibiting corrosion of
ferrous metal surfaces. Non-limiting examples of rust inhibitors
useful herein include oil-soluble high molecular weight organic
acids, such as 2-ethylhexanoic acid, lauric acid, myristic acid,
palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic
acid, and cerotic acid, as well as oil-soluble polycarboxylic acids
including dimer and trimer acids, such as those produced from tall
oil fatty acids, oleic acid, and linoleic acid. Other suitable
corrosion inhibitors include long-chain alpha, omega-dicarboxylic
acids in the molecular weight range of about 600 to about 3000 and
alkenylsuccinic acids in which the alkenyl group contains about 10
or more carbon atoms such as, tetrapropenylsuccinic acid,
tetradecenylsuccinic acid, and hexadecenylsuccinic acid. Another
useful type of acidic corrosion inhibitors are the half esters of
alkenyl succinic acids having about 8 to about 24 carbon atoms in
the alkenyl group with alcohols such as the polyglycols. The
corresponding half amides of such alkenyl succinic acids are also
useful. A useful rust inhibitor is a high molecular weight organic
acid. In some embodiments, an lubricating oil is devoid of a rust
inhibitor.
[0173] The rust inhibitor, if present, can be used in an amount
sufficient to provide about 0 wt. % to about 5 wt. %, about 0.01
wt. % to about 3 wt. %, about 0.1 wt. % to about 2 wt. %, based
upon the final weight of the lubricating oil composition.
[0174] In general terms, a suitable lubricant may include additive
components in the ranges listed in Table 1.
TABLE-US-00002 TABLE 1 Wt. % Wt. % (Suitable (Suitable Component
Embodiments) Embodiments) Dispersant(s) 0.1-20.0 1.0-8.0
Antioxidant(s) 0-5.0 0.1-3.0 Detergent(s) 1.0-15.0 1.0-8.0 Ashless
TBN booster(s) 0.0-1.0 0.0-0.5 Corrosion inhibitor(s) 0.0-5.0
0.0-2.0 Metal dihydrocarbyldithiophosphate(s) 0.1-6.0 0.1-4.0
Ash-free phosphorus 0.0-6.0 0.0-4.0 compound(s) Antifoaming
agent(s) 0.0-5.0 0.001-0.15 Antiwear agent(s) 0.0-1.0 0.0-0.8 Pour
point depressant(s) 0.0-5.0 0.01-1.5 Viscosity index improver(s)
0.0-20.0 0.25-12.0 Friction modifier(s) 0.0-5.0 0.05-2.0 Base
oil(s) Balance Balance Total 100 100
[0175] The percentages of each component above represent the weight
percent of each component, based upon the weight of the final
lubricating oil composition. The remainder of the lubricating oil
composition consists of one or more base oils.
[0176] Additives used in formulating the compositions described
herein may be blended into the base oil individually or in various
sub-combinations. However, it may be suitable to blend all of the
components concurrently using an additive concentrate (i.e.,
additives plus a diluent, such as a hydrocarbon solvent).
[0177] In certain embodiments of the present disclosure, the method
of using the lubricating oil composition is capable of reducing the
timing chain stretch to 0.2% or less, or 0.1% or less, or 0.09% or
less, as measured by the Ford Chain Wear Test over 216 hours. Also,
in certain embodiments of the invention, the engine is a spark
ignition engine or, more particularly, a spark ignition passenger
gasoline car engine.
[0178] The invention also contemplates use of the lubricating oil
compositions described above for reducing the timing chain stretch
or elongation of a timing chain of an engine such as a spark
ignition engine or a spark ignition passenger car engine.
EXAMPLES
[0179] The following examples are illustrative, but not limiting,
of the methods and compositions of the present disclosure. Other
suitable modifications and adaptations of the variety of conditions
and parameters normally encountered in the field, and which are
obvious to those skilled in the art, are within the scope of the
disclosure.
[0180] A series of tests were carried out to determine the impact
of the calcium sulfonate detergent, calcium phenate detergent and
the magnesium-containing detergent on chain stretch. The operation
of the timing chain was simulated by the Ford Chain Wear Test
described in greater detail below.
[0181] Each of the lubricating oil compositions contained a major
amount of a base oil and a base conventional dispersant inhibitor
(DI) package, wherein the base DI package provided about 8 to about
12 percent by weight of the lubricating oil composition. The base
DI package contained conventional amounts of dispersant(s),
antiwear additive(s), antioxidant(s), friction modifier(s), pour
point depressant, and viscosity index improver as set forth in
Table 2. The major amount of base oil was present in an amount of
about 74 wt. % to about 87 wt. % in the lubricating oil
composition. The components that were varied are specified in the
tables and discussion of the Examples below. All the values listed
are stated as weight percent of the component based on the total
weight of the lubricating oil composition (i.e., the amount of
component reflects active ingredient plus diluent oil, if any),
unless specified otherwise.
TABLE-US-00003 TABLE 2 Components of DI Package Wt. %
Antioxidant(s) 0.5 to 2.5 Antiwear agent(s), including any 0.0 to
5.0 metal dihydrocarbyl dithiophosphate Detergent(s)* 0.0
Dispersant (s) 2.0 to 6.0 Friction modifier(s) 0.05 to 1.25 Pour
point depressant(s) 0.05 to 0.5 Viscosity Index Improver(s) 0.25 to
9.0 *Detergent is varied in the following experiments, so for
purposes of the base formulation, the detergent amount is set to
zero.
Comparative Example A
[0182] To demonstrate the significance of wear on the chain stretch
of a timing chain, a control lubricating oil composition was used.
This composition had a viscosity grade of 5W-40 and contained more
than about 70 wt % of a base oil and an additive package free from
intentionally added magnesium detergent. Details of the detergent
components used in the composition of Comparative Example A are
shown in the Table 3 below.
Example 1
[0183] The lubricating oil composition of Example 1 had a viscosity
grade of 5W-40 and contained more than about 70 wt. % of a base oil
and an additive package containing a magnesium detergent in an
amount to supply about 910 ppm Mg to the finished fluid. Details of
the detergent components employed in the composition of Example 1
are shown in Table 3 below.
Example 2
[0184] The lubricating oil composition of Example 2 had a viscosity
grade of 5W-40 and contained more than about 70 wt. % of a base oil
and an additive package containing a magnesium detergent. Details
of the detergent components in the composition of Example 2 are
shown in Table 3 below.
Example 3
[0185] The lubricating oil composition of Example 3 had a viscosity
grade of 5W-20 and contained more than about 80 wt. % of a base oil
and an additive package containing a magnesium detergent. Details
of the detergent components contained in the composition of Example
3 are shown in Table 3 below.
Example 4
[0186] The lubricating oil composition of Example 4 had a viscosity
grade of 0W-20 and contained more than about 80 wt. % of a base oil
and an additive package containing magnesium sulfonate detergent.
Details of the detergent components of the composition of Example 4
are shown in Table 3 below.
TABLE-US-00004 TABLE 3 Example Comparative Inventive Inventive
Inventive Inventive Example A Example 1 Example 2 Example 3 Example
4 Viscosity 5 W-40 5 W-40 5 W-40 5 W-20 0 W-20 Grade Ca (ppm) 1690
840 140 840 580 from Ca sulfonate Ca (ppm) 1400 690 1400 690 800
from OB Ca Phenate Mg (ppm) 0 910 870 1480 370 from Mg sulfonate
Weight 0.54 0.34 0.06 0.28 0.33 ratio of total Ca from Ca sulfonate
to total Ca + Mg Timing 0.13% (Fail) 0.06% 0.10% 0.09% 0.07% Chain
(Pass) (Pass) (Pass) (Pass) Stretch.sup.a .sup.aA timing chain
stretch of 0.1% or less is passing rate
Ford Chain Wear Test
[0187] The lubricating oils of Comparative Example A and Examples
1-4 as set forth above were tested in the Ford Chain Wear Test
using a test duration of 216 hours and then the timing chain was
tested for timing chain stretch.
[0188] The Ford Chain Wear Test is a method of evaluating the
timing chain stretch in an engine. The Ford Chain Wear Test employs
a 2012 Ford 2.0 Liter EcoBoost TGDi four-cylinder test engine. The
procedure followed to generate data presented above, CW ASTM Draft
R18 procedure, required that the engine was run at low-to-moderate
speed and load at low and normal running temperatures in a two
stage test. The test cycle consisted of an 8 hour break-in period
followed by 216 hours of cyclic test conditions. The timing chain
was measured after the break-in period and this measurement was
used as the baseline measurement for the end-of-test timing chain
stretch calculation. At the end-of-test, the timing chain was
measured again.
[0189] Stage 1 of the test runs at low speed, low load and low
temperatures with an enriched combustion cycle. Stage 2 runs at
moderate speed, moderate load and moderate temperatures using
stoichiometric conditions. Between Stage 1 and Stage 2, the
temperatures, speeds, and loads are ramped at specified rates.
[0190] The timing chain stretch results are presented in Table 3
above.
[0191] The results obtained using the lubricating oil compositions
of Comparative Example A and Examples 1-4 show that lubrication
methods of the present invention provided improved resistance to
timing chain stretch in comparison with the lubrication method of
Comparative Example A. Comparative Example A and Examples 1-4 show
that lubrication methods employing lubricating oil compositions
comprising a magnesium-containing detergent have greatly improved
resistance to timing chain stretch when compared to lubricating oil
compositions that do not include a magnesium-containing detergent.
Also, the examples highlight that compositions that provided
reduced timing chain stretch had a weight ratio of total calcium
from calcium sulfonate detergent to the total of calcium and
magnesium, in the lubricating oil of from about 0.06 to about
0.33.
[0192] Other embodiments of the present disclosure will be apparent
to those skilled in the art from consideration of the specification
and practice of the embodiments disclosed herein. As used
throughout the specification and claims, "a" and/or "an" may refer
to one or more than one. Unless otherwise indicated, all numbers
expressing quantities of ingredients, properties such as molecular
weight, percent, ratio, reaction conditions, and so forth used in
the specification and claims are to be understood as being modified
in all instances by the term "about," whether or not the term
"about" is present. Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the specification and claims
are approximations that may vary depending upon the desired
properties sought to be obtained by the present disclosure. At the
very least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each numerical
parameter should at least be construed in light of the number of
reported significant digits and by applying ordinary rounding
techniques. Notwithstanding that the numerical ranges and
parameters setting forth the broad scope of the disclosure are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviation found in their respective
testing measurements. It is intended that the specification and
examples be considered as exemplary only, with a true scope and
spirit of the disclosure being indicated by the following
claims.
[0193] The foregoing embodiments are susceptible to considerable
variation in practice. Accordingly, the embodiments are not
intended to be limited to the specific exemplifications set forth
hereinabove. Rather, the foregoing embodiments are within the
spirit and scope of the appended claims, including the equivalents
thereof available as a matter of law.
[0194] The patentees do not intend to dedicate any disclosed
embodiments to the public, and to the extent any disclosed
modifications or alterations may not literally fall within the
scope of the claims, they are considered to be part hereof under
the doctrine of equivalents.
[0195] All patents and publications cited herein are fully
incorporated by reference herein in their entirety.
* * * * *