U.S. patent application number 10/570084 was filed with the patent office on 2007-08-23 for lubricated part having partial hard coating allowing reduced amounts of antiwear additive.
Invention is credited to Ewa A. Bardasz, Christopher G. Scott.
Application Number | 20070197407 10/570084 |
Document ID | / |
Family ID | 34312218 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070197407 |
Kind Code |
A1 |
Bardasz; Ewa A. ; et
al. |
August 23, 2007 |
Lubricated part having partial hard coating allowing reduced
amounts of antiwear additive
Abstract
A lubricated part composition containing (a) a part with at
least a partial hard surface coating of average thickness less than
about 25 micrometres, said coating containing at least one moiety
selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof; (b) a
detergent selected from at least one of the group consisting of a
phenate salt, a sulphonate salt, a salixarate salt and mixtures
thereof; and (c) an oil of lubricating viscosity. The invention
further relates to the use of the composition to decrease engine
wear, decrease sludge formation, filter plugging, decrease sulphur
emissions and decrease phosphorus emissions.
Inventors: |
Bardasz; Ewa A.; (Wickliffe,
OH) ; Scott; Christopher G.; (Wickliffe, OH) |
Correspondence
Address: |
THE LUBRIZOL CORPORATION;ATTN: DOCKET CLERK, PATENT DEPT.
29400 LAKELAND BLVD.
WICKLIFFE
OH
44092
US
|
Family ID: |
34312218 |
Appl. No.: |
10/570084 |
Filed: |
September 3, 2004 |
PCT Filed: |
September 3, 2004 |
PCT NO: |
PCT/US04/28693 |
371 Date: |
October 19, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60500715 |
Sep 5, 2003 |
|
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|
Current U.S.
Class: |
508/199 ;
508/154; 508/371; 508/390; 508/479; 508/572 |
Current CPC
Class: |
C10M 2203/1006 20130101;
C10N 2030/06 20130101; C10M 2209/086 20130101; C10M 2203/1025
20130101; C10M 2229/02 20130101; C10N 2040/252 20200501; C10M
159/20 20130101; C10M 2205/02 20130101; C10N 2030/45 20200501; C10N
2060/14 20130101; C10M 2207/289 20130101; C10N 2030/04 20130101;
C10N 2040/25 20130101; C10M 167/00 20130101; C10M 2227/061
20130101; C10M 159/22 20130101; C10M 2219/046 20130101; C10M
2219/089 20130101; C10N 2030/02 20130101; C10M 2215/28 20130101;
C10M 163/00 20130101; C10M 2205/0206 20130101; C10M 2207/026
20130101; C10M 2209/101 20130101; C10N 2030/42 20200501; C10M
159/24 20130101; C10N 2030/08 20130101; C10M 2205/026 20130101;
C10M 2223/045 20130101; C10N 2010/04 20130101; C10M 2207/262
20130101; C10N 2030/43 20200501; C10N 2050/14 20200501; C10M 165/00
20130101; C10N 2010/02 20130101; C10M 2207/028 20130101; C10N
2030/50 20200501; C10M 2223/045 20130101; C10N 2010/04 20130101;
C10M 2223/045 20130101; C10N 2010/04 20130101 |
Class at
Publication: |
508/199 ;
508/154; 508/390; 508/572; 508/479; 508/371 |
International
Class: |
C10M 141/12 20060101
C10M141/12 |
Claims
1. A lubricated part comprising: (a) a part with at least a partial
hard surface coating of average thickness less than about 25
micrometres, said coating containing at least one moiety selected
from the group consisting of silicides, nitrides, carbides,
borides, oxides, sulphides and mixtures thereof; (b) a detergent
selected from at least one of the group consisting of a phenate
salt, a sulphonate salt, a salixarate salt and mixtures thereof;
and (c) an oil of lubricating viscosity.
2. The lubricated part of claim 1, wherein the partial hard surface
coating has an average thickness less than about 8 micrometres.
3. The lubricated part of claim 1, wherein the partial hard surface
coating contains at least one moiety selected from the group
consisting of nitrides, carbides and mixtures thereof.
4. The lubricated part of claim 1, wherein the partial hard surface
coating further comprises at least one metal selected from the
group consisting of Group IVb of the periodic table, Group Vb of
the periodic table Group VIb of the periodic table and mixtures
thereof.
5. The lubricated part of claim 4, wherein the metal is selected
from the group consisting of chromium, tungsten, vanadium and
combinations thereof.
6. The lubricated part of claim 1, wherein the substrate of the
sulphonate detergent is represented by the formula
(R.sup.1).sub.k-Z--SO.sub.3M: wherein, each R.sup.1 is
independently a hydrocarbyl group with a about 6 to about 40 carbon
atoms Z is a cyclic or acyclic hydrocarbon group; M is a valence of
metal ion, hydrogen, ammonium ion, or mixtures thereof; and k is 1
to about 5.
7. The lubricated part of claim 6, wherein the substrate of the
sulphonate detergent incorporates a metal ion selected from the
group consisting of alkali metals, alkaline earth metals and
mixtures thereof.
8. The lubricated part of claim 1, wherein the substrate of the
phenate detergent is represented by the formulae: ##STR8## wherein
the number of sulphur atoms in formula (VI) y, is in the range from
1 to 8; the number of (CR.sup.10CR.sup.11) moieties y, is in the
range from 0 to 8; hydrogen or hydrocarbyl groups; each R.sup.9 are
independently hydrogen or a hydrocarbyl group; w, is in the range
from 0 to 3, provided at least one hydrocarbyl group is present on
an oligomer; T is hydrogen or an (S).sub.y linkage terminating in
hydrogen, an ion or a non-phenolic hydrocarbyl group; and M is a
valence of metal ion or hydrogen, x is an integer and present in a
sufficient number of times to form oligomers of hydrocarbyl phenol;
and R.sup.10 and R.sup.11 are hydrogen or hydrocarbyl or mixtures
thereof.
9. The lubricated part of claim 1, wherein the substrate of the
salixarate detergent is represented by a substantially linear
compound comprising at least one unit of the formulae (I) or (II):
##STR9## each end of the compound having a terminal group of
formulae (III) or (IV): ##STR10## such groups being linked by
divalent bridging groups A, which may be the same or different for
each linkage; wherein in formulas (I)-(IV) R.sup.3 is hydrogen or a
hydrocarbyl group; R.sup.2 is hydroxyl or a hydrocarbyl group and j
is 0, 1, or 2; R.sup.6 is hydrogen, a hydrocarbyl group, or a
hetero-substituted hydrocarbyl group; either R.sup.4 is hydroxyl
and R.sup.5 and R.sup.7 are independently either hydrogen, a
hydrocarbyl group, or hetero-substituted hydrocarbyl group, or else
R.sup.5 and R.sup.7 are both hydroxyl and R.sup.4 is hydrogen, a
hydrocarbyl group, or a hetero-substituted hydrocarbyl group;
provided that at least one of R.sup.4, R.sup.5, R.sup.6 and R.sup.7
is hydrocarbyl containing at least 8 carbon atoms; and wherein the
molecules on average contain at least one of unit (I) or (III) and
at least one of unit (II) or (IV) and the ratio of the total number
of units (I) and (III) to the total number of units of (II) and
(IV) in the composition is about 0.1:1 to about 2:1.
10. The lubricated part of claim 1, wherein the oil of lubricating
viscosity is selected from the group consisting of API Group II,
III, or IV oil and mixtures thereof.
11. The lubricated part of claim 1 further comprising a metal
hydrocarbyl dithiophosphate represented by the formula: ##STR11##
wherein R.sup.12 and R.sup.13 are independently hydrogen,
hydrocarbyl groups or mixtures thereof, provided that at least one
of R.sup.12 and R.sup.13 is a hydrocarbyl group; M' is a metal; and
n is an integer equal to the available valence of M'.
12. The lubricated part of claim 1 further comprising a borate
ester prepared by the reaction of a boron compound and at least one
compound selected from epoxy compounds or equivalent, alcohols and
mixtures thereof.
13. The lubricated part of claim 1 further comprising at least one
other performance additives selected from the group consisting of
detergents other than those of component (b) of the invention,
metal deactivators, dispersants, antioxidants, antiwear agents,
corrosion inhibitors, antiscuffing agents, extreme pressure agents,
foam inhibitors, demulsifiers, friction modifiers other than a
borate ester, viscosity modifiers, pour point depressants, fluidity
modifiers and seal swelling agents.
14. The lubricated part of claim 1 comprising: (a) a part with at
least a partial hard surface coating of average thickness less than
about 25 micrometres, said coating containing at least one moiety
selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof; (b) a
detergent selected from at least one of the group consisting of a
phenate salt, a sulphonate salt, a salixarate salt and mixtures
thereof; and when present, each detergent is independently present
from about 0.05 to about 20 wt % of the lubricating oil
composition; and (c) an oil of lubricating viscosity present from
about 5 to about 99.8 wt % of the lubricating oil composition; (d)
a metal hydrocarbyl dithiophosphate present from about 0 to about 5
wt % of the lubricating oil composition; (e) a borate ester present
from about 0 to about 20 wt % of the lubricating oil composition;
and (f) other performance additives present from about 0 to about
30 wt % of the lubricating oil composition.
15. The lubricated part of claim 14, wherein the lubricating oil
composition has a total sulphur content below about 0.5 wt %; the
total phosphorus content is below about 0.1 wt %; and the total
sulphated ash content is below about 1.1 wt %.
16. The lubricated part of claim 1, wherein the partial hard
surface coating is formed by at least one technique selected from
the group consisting of physical vapour deposition, chemical vapour
deposition, ion beam deposition, ion beam enhanced deposition and
plasma induced immersion process.
17. The lubricated part of claim 16, wherein the technique used to
form the partial hard surface coating is physical vapour
deposition.
18. The lubricated part of claim 1, wherein the part is located in
the valve train, fuel injector train or mixtures thereof.
19. The lubricated part of claim 18, wherein the part is selected
from at least one of the group consisting of a rocker arm, a rocker
arm pad, a cam follower, a cam lobe, a crosshead, a valve adjuster,
a injector adjuster and mixtures thereof.
20. A lubricated part comprising: (a) a part with at least a
partial hard surface coating of average thickness less than about
25 micrometres, said coating containing at least one chromium
moiety selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof; (b) a
salixarate salt detergent; and (c) an oil of lubricating
viscosity.
21. A lubricated part comprising: (a) a part with at least a
partial hard surface coating of average thickness less than about
25 micrometres, said coating containing at least one tungsten
moiety selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof; (b) a
detergent package comprising: (i) a phenate salt; (ii) a sulphonate
salt; and (c) an oil of lubricating viscosity.
22. A method for lubricating a part, wherein the lubricated part
has at least one property selected from the group consisting of
decreased wear, decreased filter plugging, decreased sludge
formation, decreased phosphorus emissions, decreased sulphur
emissions, decreased sulphated ash formation and mixtures thereof;
the method comprising a lubricated part comprising: (a) a part with
at least a partial hard surface coating of average thickness less
than about 25 micrometres, said coating containing at least one
moiety selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof; (b) a
detergent selected from at least one of the group consisting of a
phenate salt, a sulphonate salt, a salixarate salt and mixtures
thereof; and (c) an oil of lubricating viscosity.
Description
FIELD OF INVENTION
[0001] The present invention relates to a lubricated engine part
composition with a partial hard surface coating of average
thickness in combination with detergents and an oil of lubricating
viscosity. The composition has improved antiwear performance and/or
decreased filter plugging.
BACKGROUND OF THE INVENTION
[0002] It is well known for lubricating oils to contain a number of
additives used to protect the engine from wear, the accumulation of
sludge and filter plugging. Common additives for engine lubricating
oils are zinc alkyldithiophosphate (ZDDP) an antiwear additive, and
overbased calcium sulphonate detergents. It is believed that ZDDP
antiwear additives protect the engine by forming a protective film
on metal surfaces. Typical treatment quantities of ZDDP range from
1 to 2 weight percent based on the total weight of the lubricant.
Detergents such as overbased calcium sulphonate help keep the
engine parts clean of soot and other deposits, and offer an
alkalinity reserve. Typical treatment quantities of detergents
range from 0.05 to 10 weight percent based on the total weight of
the lubricant.
[0003] In recent years phosphates and sulphonates derived from
engine lubricants have been shown to contribute in part to
particulate emissions. Further, sulphur and phosphorus tend to
poison the NO.sub.x catalysts used in catalytic converters,
resulting in a reduction in performance of said catalysts. Any
reduction in the performance of catalytic converters tends to
result in increased amounts of greenhouse gases such as nitric
oxide and/or sulphur oxides. However, reducing the amount
phosphates and sulphonates by decreasing the amount of ZDDP and/or
calcium sulphonate detergents will increase the amount of wear in
an engine especially on engine parts with high loading for instance
in the valve train and increase the amount of sludge formed.
Conversely reducing the amount phosphates and sulphonates will
decrease filter plugging because divalent metals such as zinc and
calcium are known to help form material capable of plugging
filters, for instance, sulphonated ash.
[0004] The valve train metal parts are often iron or steel and
these are chemically or physically modified to provide better
antiwear performance. The process often involves heating the metal
part to above about 600.degree. C. followed by rapid cooling (or
quenching) in water and/or an oil of lubricating viscosity. The
metal part is then suitable for use and provides good protection
against wear in the presence of antiwear additives such as ZDDP.
However ZDDP has the disadvantages mentioned above.
[0005] Therefore there is a need for an engine part to be
lubricated with a composition capable of reducing sulphur and
phosphorus content without having an adverse effect on antiwear
performance, sludge formation or increased filter plugging.
[0006] It would be desirable to have a lubricated part capable of
decreasing wear of said part. The present invention provides a
lubricated part capable of decreasing wear of said part.
[0007] It would be desirable to have a lubricated part capable of
decreasing filter plugging. The present invention provides a
lubricated part capable of decreasing filter plugging.
[0008] It would be desirable to have a lubricated part capable of
decreasing sludge formation. The present invention provides a
lubricated part capable of decreasing sludge formation.
[0009] It would be desirable to have a lubricated part capable of
decreasing phosphorus emissions. The present invention provides a
lubricated part capable of decreasing phosphorus emissions.
[0010] It would be desirable to have a lubricated part capable of
decreasing sulphur emissions. The present invention provides a
lubricated part capable of decreasing sulphur emissions.
[0011] It would be desirable to have a lubricated part capable of
decreasing the amount of sulphonated ash. The present invention
provides a lubricated part capable of decreasing the amount of
sulphonated ash.
SUMMARY OF THE INVENTION
[0012] The present invention provides a lubricated part
comprising:
[0013] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one moiety selected from the group consisting
of silicides, nitrides, carbides, borides, oxides, sulphides and
mixtures thereof;
[0014] (b) a detergent selected from at least one of the group
consisting of a phenate salt, a sulphonate salt, a salixarate salt
and mixtures thereof, and
[0015] (c) an oil of lubricating viscosity.
[0016] The invention further provides a lubricated part
comprising:
[0017] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one tungsten moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0018] (b) a detergent package comprising: [0019] (i) a phenate
salt; [0020] (ii) a sulphonate salt; and
[0021] (c) an oil of lubricating viscosity.
[0022] The invention further provides a lubricated part
comprising:
[0023] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one chromium moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0024] (b) a salixarate salt detergent; and
[0025] (c) an oil of lubricating viscosity.
[0026] The invention further provides a method for lubricating a
part, wherein the lubricated part has at least one property
selected from the group consisting of decreased wear, decreased
filter plugging, decreased sludge formation, decreased phosphorus
emissions, decreased sulphur emissions, decreased sulphated ash
formation and mixtures thereof; the method comprising a lubricated
part comprising.
[0027] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one moiety selected from the group consisting
of silicides, nitrides, carbides, borides, oxides, sulphides and
mixtures thereof;
[0028] (b) a detergent selected from at least one of the group
consisting of a phenate salt, a sulphonate salt, a salixarate salt
and mixtures thereof; and
[0029] (c) an oil of lubricating viscosity.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention provides a lubricated part
comprising:
[0031] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one moiety selected from the group consisting
of silicides, nitrides, carbides, borides, oxides, sulphides and
mixtures thereof;
[0032] (b) a detergent selected from at least one of the group
consisting of a phenate salt, a sulphonate salt, a salixarate salt
and mixtures thereof; and
[0033] (c) an oil of lubricating viscosity.
[0034] In one aspect of the invention provides a lubricated part
comprising:
[0035] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one tungsten moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0036] (b) a detergent package comprising: [0037] (i) a phenate
salt; [0038] (ii) a sulphonate salt; and
[0039] (c) an oil of lubricating viscosity.
[0040] In one aspect of the invention provides a lubricated part
comprising:
[0041] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one chromium moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0042] (b) a salixarate salt detergent; and
[0043] (c) an oil of lubricating viscosity.
[0044] In one aspect of the invention provides a method for
lubricating a part, wherein the lubricated part has at least one
property selected from the group consisting of decreased wear,
decreased filter plugging, decreased sludge formation, decreased
phosphorus emissions, decreased sulphur emissions, decreased
sulphated ash formation and mixtures thereof, the method comprising
a lubricated part comprising:
[0045] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one moiety selected from the group consisting
of silicides, nitrides, carbides, borides, oxides, sulphides and
mixtures thereof;
[0046] (b) a detergent selected from at least one of the group
consisting of a phenate salt, a sulphonate salt, a salixarate salt
and mixtures thereof; and
[0047] (c) an oil of lubricating viscosity.
[0048] In one aspect of the invention provides a method for
lubricating a part, wherein the lubricated part has at least one
property selected from the group consisting of decreased wear,
decreased filter plugging, decreased sludge formation, decreased
phosphorus emissions, decreased sulphur emissions, decreased
sulphated ash formation and mixtures thereof; the method comprising
a lubricated part comprising:
[0049] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one tungsten moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0050] (b) a detergent package comprising: [0051] (i) a phenate
salt; [0052] (ii) a sulphonate salt; and
[0053] (c) an oil of lubricating viscosity.
[0054] In one aspect of the invention provides a method for
lubricating a part, wherein the lubricated part has at least one
property selected from the group consisting of decreased wear,
decreased filter plugging, decreased sludge formation, decreased
phosphorus emissions, decreased sulphur emissions, decreased
sulphated ash formation and mixtures thereof; the method comprising
a lubricated part comprising:
[0055] (a) a part with at least a partial hard surface coating of
average thickness less than about 25 micrometres, said coating
containing at least one chromium moiety selected from the group
consisting of silicides, nitrides, carbides, borides, oxides,
sulphides and mixtures thereof;
[0056] (b) a salixarate salt detergent; and
[0057] (c) an oil of lubricating viscosity.
Lubricated Part
[0058] The lubricated part can be metal or a non-metal, for
instance a polymeric material or a ceramic material, although metal
parts are preferred. Typically the lubricated part can be located
in an engine, the drive train or other areas where there can be
boundary lubrication. Preferably the lubricated part can be located
in an engine. Often the lubricated part can include parts within
the engine such as a crankshaft, a piston, a piston ring, auxiliary
components the valve train, fuel injector train or mixtures
thereof. Preferably the lubricated part can include the valve train
components such as a camshaft, a cam follower, a valve adjuster, a
crosshead, a rocker arm, a rocker arm pad, a lobe, a push rod or
mixtures thereof; or the fuel injector train such as an injector
adjuster. In one embodiment the lubricated part is the rocker arm
and rocker arm pads. In one embodiment the lubricated part is the
cam follower and the cam lobe. In one embodiment the lubricated
part is the crosshead. In one embodiment the lubricated part is the
valve adjuster. In one embodiment the lubricated part is the
injector adjuster.
Partial Hard Surface Coating
[0059] The partial hard surface coating of the invention are known
in the art and are typically used to in areas where there is a need
for boundary lubrication, for instance, metal to metal contact. The
partial hard surface coating is applied to the surface in a
sufficient amount to cover the contact area i.e. where boundary
lubrication is required. Typically a partial hard surface will have
an average thickness less than about 25 micrometres, preferably
less than about 20 micrometres, more preferably less than about 15
micrometres, even more preferably less than about 12 micrometres
and even more preferably less than about 8 micrometres. Often the
average coating thickness will be in the range about 50 nanometres
to about 25 micrometres, preferably about 100 nanometres to about
20 micrometres, more preferably about 300 nanometres to about 15
micrometres, even more preferably about 600 nanometres to about 10
micrometres and even more preferably about 900 nanometres to about
5 micrometres. In one embodiment the average coating thickness is
between about 3 micrometres and about 5 micrometres. In one
embodiment the average coating thickness is between about 2
micrometres and about 4 micrometres.
[0060] The partial hard surface coating contains at least one
moiety selected from the group consisting of silicides, nitrides,
carbides, borides, oxides, sulphides and mixtures thereof.
Preferably the coating contains at least one moiety selected from
the group consisting of nitrides, carbides and mixtures thereof. In
one embodiment the coating contains nitrides. In one embodiment the
coating contains carbides. In one embodiment the coating can
include sulphides such as molybdenum sulphide. In one embodiment
the coating can be substantially free of to free of sulphides such
as molybdenum sulphide. In one embodiment the coating can include
oxides such as tungsten oxide. In one embodiment the coating can be
substantially free of to free of oxides such as tungsten oxide.
[0061] Typically the silicides, nitrides, carbides, borides, oxides
and sulphides incorporate at least one metal selected from the
group consisting of Group IVb of the periodic table, Group Vb of
the periodic table Group VIb of the periodic table and mixtures
thereof. Examples of suitable metals include chromium, molybdenum,
tungsten, vanadium, titanium or mixtures thereof. Preferably the
metals are selected from the group consisting of chromium,
tungsten, vanadium and mixtures thereof. In one embodiment the
metal is chromium. In one embodiment the metal is tungsten.
[0062] The partial hard surface coating can be selected from at
least one of vanadium silicide, vanadium nitride, vanadium carbide,
vanadium boride, vanadium oxide, vanadium sulphide, tungsten
silicide, tungsten nitride, tungsten carbide, tungsten boride,
tungsten oxide, tungsten sulphide, chromium silicide, chromium
nitride, chromium carbide, chromium boride, chromium oxide,
chromium sulphide and mixtures thereof. Typically the partial hard
surface coating will have a Vickers hardness (VHN) from about 700
to about 2500, preferably about 800 to about 2000 and even more
preferably about 900 to about 1900. In one embodiment the VHN is
from about 900 to about 1350.
[0063] In one embodiment the partial hard surface coating is
tungsten carbide. Typically tungsten carbide has a VHN hardness of
700 or more, preferably 850 or more and more preferably 950 or
more. In one embodiment the hardness is about 1000. In one
embodiment the average coating thickness is between about 2 to
about 4 micrometres. A typical commercially available tungsten
carbide coating suitable for the invention is Balinit.RTM.C. This
tungsten carbide coating is available from Balzers Limited.
[0064] In one embodiment the partial hard surface coating is
chromium nitride. Typically chromium nitride has a hardness of 1200
or more, preferably 1450 or more and more preferably 1600 or more
Vickers hardness (VHN). In one embodiment the hardness is about
1750 VHN. In one embodiment the average coating thickness is
between about 3 to about 5 micrometres. A typical commercially
available chromium nitride coating suitable for the invention is
Balinit.RTM.D. This chromium nitride coating is available from
Balzers Limited.
[0065] The partial hard surface coating can be deposited onto the
part to be lubricated as a singular layer or as part of multi
layer. A multi layer can have one or more of the coatings described
above, for example a chromium nitride layer and then a tungsten
carbide layer. Also in some instances an adhesive layer may be
required. In one embodiment the partial hard surface coating is
deposited as a single layer.
[0066] The partial hard surface coating can be deposited onto the
part to be lubricated by a number of techniques, for instance,
physical vapour deposition (PVD), chemical vapour deposition (CVD),
ion beam deposition (also referred to as IBD or IBAD), ion beam
enhanced deposition (IBED) and plasma induced immersion process
techniques. Preferably the partial hard surface coating can be
deposited onto the part to be lubricated by physical vapour
deposition. Typical physical vapour deposition techniques include
PVD ion plating or PVD magnetron sputtering. In one embodiment the
partial hard surface coating is deposited by PVD ion plating. In
one embodiment the partial hard surface coating is deposited by PVD
magnetron sputtering.
[0067] As used herein, the term "hydrocarbyl substitutent" 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:
[0068] hydrocarbon substitutents, that is, aliphatic (e.g., alkyl
or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl)
substitutents, and aromatic-, aliphatic-, and alicyclic-substituted
aromatic substitutents, as well as cyclic substitutents wherein the
ring is completed through another portion of the molecule (e.g.,
two substitutents together form a ring);
[0069] substituted hydrocarbon substitutents, that is,
substitutents containing non-hydrocarbon groups which, in the
context of this invention, do not alter the predominantly
hydrocarbon nature of the substitutent (e.g., halo (especially
chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto,
nitro, nitroso, and sulfoxy); %
[0070] hetero substitutents, that is, substitutents which, while
having a predominantly hydrocarbon character, in the context of
this invention, contain other than carbon in a ring or chain
otherwise composed of carbon atoms. Heteroatoms include sulfur,
oxygen, nitrogen, and encompass substitutents as pyridyl, furyl,
thienyl and imidazolyl. In general, no more than two, preferably no
more than one, non-hydrocarbon substitutent will be present for
every ten carbon atoms in the hydrocarbyl group; typically, there
will be no non-hydrocarbon substitutents in the hydrocarbyl
group.
Sulphonate Salt Detergent
[0071] The substrate of the sulphonate detergent of the composition
can be represented by the formula (R.sup.1).sub.k-Z--SO.sub.3M:
wherein, each R.sup.1 is independently an alkyl, cycloalkyl, aryl,
acyl, or other hydrocarbyl group with a 6 to 40, preferably 8 to 25
and even more preferably 9 to 20 carbon atoms; Z can be
independently a cyclic or acyclic hydrocarbon group; M can be
hydrogen, a valence of a metal ion, an ammonium ion and mixtures
thereof, provided hydrogen is present on less than 50%, preferably
less than 30%, more preferably less than 20%, even more preferably
less than 10% and even more preferably less than 5% of the
available M entities; and k is an integer between 1 and 5, for
example 1, 2, 3, 4, 5 or mixtures thereof. Preferably k is between
1 and 3, more preferably 1 or 2 and even more preferably 1.
[0072] In one embodiment k is 1 and R.sup.1 is a branched alkyl
group with 6 to 40 carbon atoms. In one embodiment k is 1 and
R.sup.1 is a linear alkyl group with 6 to 40 carbon atoms.
[0073] The most preferred sulphonate components are calcium
polypropene benzenesulphonate; and calcium monoalkyl- and/or
dialkyl-benzenesulphonate wherein the alkyl groups contain at least
10 carbon atoms, for example, 11 carbon atoms, 12 carbon atoms, 13
carbon atoms, 14 carbon atoms, 15 carbon atoms and mixtures
thereof.
[0074] When M is a valence of a metal ion, the metal can be
monovalent, divalent, trivalent or mixtures of such metals. When
monovalent, the metal M can be an alkali metal, preferably lithium,
sodium, or potassium; and more preferably potassium, which can be
used alone or in combination with other metals. When divalent, the
metal M can be an alkaline earth metal, preferably magnesium,
calcium, barium or mixtures of such metals, more preferably
calcium, which can be used alone or in combination with other
metals. When trivalent, the metal M can be aluminum, which can be
used alone or in combination with other metals. In one embodiment
the metal is an alkaline earth metal. In one embodiment the metal
is calcium, which can be used alone or in combination with other
metals.
[0075] When Z is cyclic hydrocarbon group, suitable groups include
phenyl or fused bicyclic groups such as naphthalene, indenyl,
indanyl, bicyclopentadienyl and mixtures thereof. Although Z can be
a fused bicyclic ring, benzene rings are preferred.
[0076] When Z is an acyclic hydrocarbon group, the carbon chain can
be linear or branched, although linear is preferred. Suitable
groups include derivatives of carboxylic acids containing 7 to 30,
preferably 7 to 20, more preferably 8 to 20 and even more
preferably 8 to 15 carbon atoms. Further the chain can be saturated
or unsaturated, although saturated is preferred.
[0077] Typically an overbased sulphonate detergent has a TBN (total
base number) in the range of about 300 to about 600, preferably
about 310 to about 580, more preferably about 320 to about 540 and
even more preferably about 330 to about 510. In one embodiment the
overbased sulphonate detergent has a TBN of about 400. The
overbased sulphonate detergent may be used alone or with other
detergents.
[0078] The sulphonate detergent can overbased or non-overbased,
although overbased is preferred. Overbased material, otherwise
referred to as overbased or superbased salts, are generally single
phase, homogeneous Newtonian systems characterised by a metal
content in excess of that which would be present for neutralisation
according to the stoichiometry of the metal and the particular
acidic organic compound reacted with the metal. The overbased
materials are prepared by reacting an acidic material (typically an
inorganic acid or lower carboxylic acid, preferably carbon dioxide)
with a mixture comprising an acidic organic compound, a reaction
medium comprising at least one inert, organic solvent (mineral oil,
naphtha, toluene, xylene, etc.) for said acidic organic material, a
stoichiometric excess of a metal base, and a promoter such as a
phenol or alcohol. A mixture of alcohols typically contains
methanol and at least one alcohol with 2 to 7 carbon atoms. The
acidic material will normally have a sufficient number of carbon
atoms to provide a degree of solubility in oil. The amount of
excess metal is commonly expressed in terms of metal ratio. The
term "metal ratio" is the ratio of the total equivalents of the
metal to the equivalents of the acidic organic compound. A neutral
metal salt has a metal ratio of one. A salt having 4.5 times as
much metal as present in a normal salt will have metal excess of
3.5 equivalents, or a ratio of 4.5.
[0079] When present, the sulphonate detergent is typically present
at about 0.05 to about 20, preferably about 0.1 to about 10, and
more preferably about 0.2 to about 8 and even more preferably about
0.5 to about 5 weight percent of the lubricating oil
composition.
Salixarate Salt Detergent
[0080] The substrate of the salixarate detergent of the invention
can be represented by a substantially linear compound comprising at
least one unit of the formulae (I) or (II): ##STR1## each end of
the compound having a terminal group of formulae (III) or (IV):
##STR2## such groups being linked by divalent bridging groups A,
which may be the same or different for each linkage; wherein in
formulas (I)-(IV) R.sup.3 is hydrogen or a hydrocarbyl group;
R.sup.2 is hydroxyl or a hydrocarbyl group and j is 0, 1, or 2;
R.sup.6 is hydrogen, a hydrocarbyl group, or a hetero-substituted
hydrocarbyl group; either R.sup.4 is hydroxyl and R.sup.5 and
R.sup.7 are independently either hydrogen, a hydrocarbyl group, or
hetero-substituted hydrocarbyl group, or else R.sup.5 and R.sup.7
are both hydroxyl and R.sup.4 is hydrogen, a hydrocarbyl group, or
a hetero-substituted hydrocarbyl group; provided that at least one
of R.sup.4, R.sup.5, R.sup.6 and R.sup.7 is hydrocarbyl containing
at least 8 carbon atoms; and wherein the molecules on average
contain at least one of unit (I) or (III) and at least one of unit
(II) or (IV) and the ratio of the total number of units (I) and
(III) to the total number of units of (II) and (IV) in the
composition is about 0.1:1 to about 2:1.
[0081] The divalent bridging group "A," which may be the same or
different in each occurrence, includes --CH.sub.2-- (methylene
bridge) and --CH.sub.2OCH.sub.2-- (ether bridge), either of which
may be derived from formaldehyde or a formaldehyde equivalent
(e.g., paraform, formalin).
[0082] Salixarate derivatives and methods of their preparation are
described in greater detail in U.S. Pat. No. 6,200,936 and PCT
Publication WO 01/56968. It is believed that the salixarate
derivatives have a predominantly linear, rather than macrocyclic,
structure, although both structures are intended to be encompassed
by the term "salixarate."
[0083] Preparative Example. Overbased Salixarate
[0084] Step (a). A reactor is charged with 15 kg (23.3 moles) of
polyisobutenyl ( M.sub.n 550) substituted phenol and 10.7 kg 150 N
mineral oil. The materials are heated, under nitrogen, to
35.degree. C., then 120 g (1.07 moles) aqueous KOH is added via a
pump and charge line, which is subsequently washed into the reactor
with 100 mL distilled water. The mixture is heated to 75.degree. C.
over 0.5 hour and 2.6 kg (32.1 moles) of 37% aqueous formaldehyde
is added via a pump and charge line over 0.5 hour, subsequently
washed into the reactor with 300 mL distilled water. The mixture is
held at temperature for 2 hours, whereupon 1.65 kg salicylic acid
(12 moles) is added followed by heating to 99.degree. C. and
reflux. The reaction mixture is further heated to 140.degree. C.
over 1 hour, removing 2.6 L aqueous distillate. The mixture is
maintained at 140.degree. C. for 1.5 hour at atmospheric pressure,
followed by 0.5 hour at 60 kPa (0.6 bar), collecting some
additional aqueous distillate.
[0085] Step (b). A reactor is charged with 13.0 kg (8.95 moles) of
the cooled product of step (a), 2.33 kg (31.5 moles) Ca(OH).sub.2,
and 450 g ethylene glycol. While stirring, 7.38 kg of
2-ethylhexanol are added over 0.3 hours. The mixture is heated at
95.degree. C. at reduced pressure (80 kPa to 44 kPa [0.2 to 0.56
bar vacuum]) over 3/4 hour, followed by 130.degree. C. over 1/4
hour at 80 kPa (0.2 bar vacuum), during which time 0.5 L aqueous
distillate is collected. An additional 2.16 kg ethylene glycol is
added is added over about 0.3 hour at 125 to 130.degree. C.
Pressure is reduced to 90 kPa (0.1 bar vacuum) and then carbon
dioxide is passed into the mixture at 500 g/hour until a total of
750 g is added. After carbonation is complete, the temperature is
increased to 200.degree. C. and the pressure reduced to 44 kPa
(0.56 bar vacuum) and maintained for a total of about 2.2 hours,
during which time 9.5 L aqueous distillate is collected. The
product is an overbased calcium salixarate.
[0086] It is believed that a significant fraction of salixarate
molecules (prior to neutralisation) may be represented on average
by the following formula: ##STR3## wherein each R.sup.8 can be the
same or different, and are an alkyl group, and, in a preferred
embodiment, is a polyisobutene group (especially of molecular
weight 200 to 1,000, or about 550). Significant amounts of di- or
trinuclear species may also be present containing one salicylic end
group of formula (III). The salixarate detergent may be used alone
or with other detergents.
[0087] When present, the salixarate detergent is typically present
at about 0.05 to about 20, preferably about 0.1 to about 10, and
more preferably about 0.2 to about 8 and even more preferably about
0.5 to about 5 weight percent of the lubricating oil
composition.
Phenate Salt Detergent
[0088] The substrate of the phenate detergent of the composition
can be represented by the formulae: ##STR4## wherein the number of
sulphur atoms in formula (VI) y, can be in the range from 1 to 8,
preferably 1 to 6 and even more preferably 1 to 4; the number of
(CR.sup.10CR.sup.11) moieties y in formula (VII), can be in the
range from 0 to 8, preferably 0 to 4 and even more preferably 0 to
2. In one embodiment y=1 in formula (VI), and the phenate detergent
is often described in the art as a sulphur containing phenate. In
one embodiment y=0 in formula (VII), and the phenate detergent is
often described in the art as "normal." In one embodiment y=1 in
formula (VII), and the phenate detergent is often described in the
art as "alkylene coupled", especially "methylene coupled."
[0089] R.sup.9 can be the same or different and are independently
hydrogen or a hydrocarbyl group. When R.sup.9 is hydrocarbyl group,
a preferred group is an alkyl group, and, in a more preferred
embodiment, is a polyisobutene group (especially of molecular
weight 200 to 1,000, or about 550); T is hydrogen or an (S).sub.y
linkage terminating in hydrogen, an ion or a non-phenolic
hydrocarbyl group; and M is as described above for the sulphonate
detergent.
[0090] x is an integer and present in a sufficient number of times
to form oligomers of hydrocarbyl phenol. Oligomers are described as
dimers, trimers, tetramers, pentamers and hexamers when x is equal
to 0, 1, 2, 3, 4, 5 and 6 respectively to form a substrate.
Typically the number of oligomers represented by x can be in the
range from 0 to 10, preferably 0 to 9, more preferably 0 to 8, even
more even more preferably 0 to 6 and even more preferably 0 to
4.
[0091] The number of R.sup.9 and/or substitutents other than
hydrogen on each hydrocarbyl phenol ring w, can be in the range
from 0 to 3, more preferably 1 to 2 and even more preferably 1,
provided at least one hydrocarbyl group is present on an oligomer.
In one embodiment w is 1 and located at para position relative to
the OM group. Typically, the minimum number of carbon atoms present
on all hydrocarbyl groups to ensure oil solubility can be 8 or
preferably 9. When two or more hydrocarbyl groups are present in
the same substrate molecule, they may be the same or different.
R.sup.10 and R.sup.11 can be hydrogen or hydrocarbyl or mixtures
thereof, preferably at least one is hydrogen and even more
preferably both are hydrogen.
[0092] Typically the sulphur containing phenate detergent has a TBN
in the range of 30 to 300, preferably 80 to 290, more preferably
100 to 280 and even more preferably 120 to 270. In one embodiment
the sulphur containing phenate detergent has a TBN of about 250.
The sulphur containing phenate detergent may be used alone or with
other sulphur containing phenate detergents.
[0093] When present, the phenate detergent is typically present at
about 0.05 to about 20, preferably about 0.1 to about 10, and more
preferably about 0.2 to about 8 and even more preferably about 0.5
to about 5 weight percent of the lubricating oil composition.
Oils of Lubricating Viscosity
[0094] The lubricating oil composition of the present invention can
be added to an oil of lubricating viscosity. The oil includes
natural and synthetic oils, oil derived from hydrocracking,
hydrogenation, hydrofinishing, unrefined, refined and re-refined
oils, or mixtures thereof.
[0095] Unrefined oils are those obtained directly from a natural or
synthetic source generally without (or with little) further
purification treatment.
[0096] Refined oils are similar to the unrefined oils except they
have been further treated in one or more purification steps to
improve one or more properties. Purification techniques are known
in the art and include solvent extraction, secondary distillation,
acid or base extraction, filtration, percolation and the like.
[0097] Re-refined oils are also known as reclaimed or reprocessed
oils, and are obtained by processes similar to those used to obtain
refined oils and often are additionally processed by techniques
directed to removal of spent additives and oil breakdown
products.
[0098] Natural oils useful in making the inventive lubricants
include animal oils, vegetable oils (e.g., castor oil, lard oil),
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 and
oils derived from coal or shale or mixtures thereof.
[0099] Synthetic lubricating oils are useful and include
hydrocarbon oils such as polymerised and interpolymerised olefins
(e.g., polybutylenes, polypropylenes, propyleneisobutylene
copolymers); poly(1-hexenes), poly(1-octenes), poly(1-decenes), and
mixtures thereof; alkyl-benzenes (e.g. dodecylbenzenes,
tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes);
polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls);
alkylated diphenyl ethers and alkylated diphenyl sulphides and the
derivatives, analogs and homologs thereof or mixtures thereof.
[0100] Other synthetic lubricating oils include but are not limited
to polyol esters, liquid esters of phosphorus-containing acids
(e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl
ester of decane phosphonic acid), and polymeric tetrahydrofurans.
Synthetic oils may be produced by Fischer-Tropsch reactions and
typically may be hydroisomerised Fischer-Tropsch hydrocarbons or
waxes.
[0101] Oils of lubricating viscosity can also be defined as
specified in the American Petroleum Institute (API) Base Oil
Interchangeability Guidelines. The five base oil groups are as
follows: Group I (sulphur content >0.03 wt %, and/or <90 wt %
saturates, viscosity index 80-120); Group II (sulphur content
.ltoreq.0.03 wt %, and .gtoreq.90 wt % saturates, viscosity index
80-120); Group III (sulphur content .ltoreq.0.03 wt %, and
.gtoreq.90 wt % saturates, viscosity index .ltoreq.120); Group IV
(all polyalphaolefins (PAO's)); and Group V (all others not
included in Groups I, II, III, or IV). The oil of lubricating
viscosity is selected from the group consisting of API Group I, II,
III, IV, V oil and mixtures thereof. Preferably the oil of
lubricating viscosity is selected from the group consisting of API
Group II, III, or IV oil and mixtures thereof. If the oil of
lubricating viscosity is an API Group II, III, or IV oil there can
be up to a maximum of about 49.9 wt %, preferably up to a maximum
of about 40 wt %, more preferably up to a maximum of about 30 wt %,
even more preferably up to a maximum of about 20 wt %, even more
preferably up to a maximum of about 10 wt % and even more
preferably up to a maximum of about 5 wt % of the lubricating oil
an API Group I or V oil.
[0102] The oil of lubricating viscosity is typically present at
about 5 to about 99.8, preferably about 42 to about 98.7, and more
preferably about 55.2 to about 97.3 and even more preferably about
69.3 to about 95.4 weight percent of the lubricating oil
composition.
[0103] If the present invention is in the form of a concentrate
(which can be combined with additional oil to form, in whole or in
part, a finished lubricant), the ratio of each of the
above-mentioned dispersant, as well as other components, to diluent
oil is typically in the range of about 80:20 to about 10:90 by
weight.
Metal Hydrocarbyl Dithiophosphate
[0104] The invention can further contain a metal hydrocarbyl
dithiophosphate that can be represented by the formula: ##STR5##
wherein R.sup.12 and R.sup.13 are independently hydrogen,
hydrocarbyl groups or mixtures thereof, provided that at least one
of R.sup.12 and R.sup.13 is a hydrocarbyl group, preferably alkyl
or cycloalkyl with 1 to about 30, preferably about 2 to about 20
and even more preferably about 2 to about 15 carbon atoms.
[0105] M' is a metal, and n is an integer equal to the available
valence of M'. M' is mono- or di- or tri- valent, preferably
divalent, more preferably a divalent transition metal. In one
embodiment M' is zinc. In one embodiment M' is calcium. In one
embodiment M' is barium.
[0106] Examples of suitable zinc hydrocarbyl dithiophosphates
(often referred to as ZDDP, ZDP or ZDTP) can include zinc isopropyl
methylamyl dithiophosphate, zinc isopropyl isooctyl
dithiophosphate, barium di-(nonyl)-dithiophosphate, zinc
di-(cyclohexyl) dithiophosphate, zinc di-(isobutyl)
dithiophosphate, calcium di-(hexyl) dithiophosphate, zinc isobutyl
isoamyl dithiophosphate, zinc isopropyl n-butyl dithiophosphate,
isobutyl primary amyl dithiophosphate, methylamyl dithiophosphate,
isopropyl 2-ethylhexyl dithiophosphate, and mixtures thereof. Other
suitable metal hydrocarbyl dithiophosphates include barium
di-(nonyl)-dithiophosphate, calcium di-(hexyl) dithiophosphate and
mixtures thereof.
[0107] The metal hydrocarbyl dithiophosphates can typically be
present at 0 to about 5, preferably about 0.01 to about 3, and more
preferably about 0.05 to about 0.8 and even more preferably about
0.07 to about 0.7 wt % of the lubricating oil composition. In one
embodiment the metal hydrocarbyl dithiophosphates are present at
less than 1 wt % of the lubricating oil composition. In one
embodiment the metal hydrocarbyl dithiophosphates are present at
less than 0.8 wt % of the lubricating oil composition. In one
embodiment the metal hydrocarbyl dithiophosphates are present at
less than 0.6 wt % of the lubricating oil composition. In one
embodiment the metal hydrocarbyl dithiophosphates can be present at
about 0.5 weight percent of the lubricating oil composition.
Borated Ester
[0108] The invention may further contain a borate ester friction
modifier. The borate ester can be prepared by the reaction of a
boron compound and at least one compound selected from epoxy
compounds, halohydrin compounds, epihalohydrin compounds, alcohols
and mixtures thereof. Typically the alcohols include monohydric
alcohols, dihydric alcohols, trihydric alcohols or higher alcohols.
Hereinafter "epoxy compound or equivalent is used when referring to
"at least one compound selected from epoxy compounds, halohydrin
compounds, epihalohydrin compounds, alcohols and mixtures
thereof."
[0109] Boron compounds suitable for preparing the borate ester
include the various forms selected from the group consisting of
boric acid (including metaboric acid, HBO.sub.2, orthoboric acid,
H.sub.3BO.sub.3, and tetraboric acid, H.sub.2B.sub.4O.sub.7), boric
oxide, boron trioxide and alkyl borates. The borate ester can also
be prepared from boron halides.
[0110] The borate ester formed by the reaction of a boron compound
and an epoxy compound or equivalent can be represented by at least
one formula selected from: ##STR6## wherein R.sup.14, R.sup.15 and
R.sup.16 can be hydrogen or hydrocarbyl groups provided at least
one, preferably at least two of R.sup.14, R.sup.15 and R.sup.16 are
hydrocarbyl groups. In one embodiment, R.sup.14 is a hydrocarbyl
group; and R's and R.sup.16 are hydrogen. In one embodiment,
R.sup.14 and R.sup.15 are hydrocarbyl groups and R.sup.16 is
hydrogen. In one embodiment R.sup.14, R.sup.15 and R.sup.16 are all
hydrocarbyl groups. The hydrocarbyl groups can be alkyl, aryl or
cycloalkyl when any 2 adjacent R groups are connected in a ring.
When alkyl, the group can be saturated or unsaturated, although
unsaturated is preferred. In one embodiment the hydrocarbyl group
is cyclic. In one embodiment the hydrocarbyl groups are mixtures of
alkyl and cycloalkyl.
[0111] Typically there is no upper limit on the number of carbon
atoms, but a practical limit is about 500, preferably about 400,
more preferably about 200, even more preferably about 100 or about
60. For example the number of carbon atoms present in R.sup.14,
R.sup.15 and R.sup.16 can be 1 to about 60, preferably 1 to about
40 and more preferably 1 to about 30 carbon atoms, provided the
total number of carbon atoms in R.sup.14, R.sup.15 and R.sup.16 is
about 9 or more, preferably about 10 or more, more preferably about
12 or more or about 14 or more.
[0112] In one embodiment R.sup.14, R.sup.15 and R.sup.16 are all
hydrocarbyl groups containing 1 to about 30 carbon atoms, provided
the total number of carbon atoms in R.sup.14, R.sup.15 and R.sup.16
is about 9 or more.
[0113] R.sup.17 to R.sup.23 inclusive can be hydrogen or
hydrocarbyl groups, provided at least one of R.sup.17 to R.sup.20
and/or R.sup.21 to R.sup.23 is a hydrocarbyl group. R.sup.24 to
R.sup.29 inclusive are hydrocarbyl groups or hydrogen, although
hydrocarbyl groups are preferred; and R.sup.30 can be hydrogen or a
hydrocarbyl group, although hydrogen is preferred. The hydrocarbyl
group definition for R.sup.17 to R.sup.30 inclusive is the same as
the definition given for R.sup.14, R.sup.15 and R.sup.16.
[0114] Examples of groups suitable for R.sup.14 to R.sup.30
inclusive include isopropyl, n-butyl, isobutyl, amyl, 2-pentenyl,
4-methyl-2-pentyl, 2-ethyl-1-hexyl, 2-ethylhexyl, heptyl, isooctyl,
nonyl, decyl, undecyl, dodecenyl, dodecyl, tridecyl, tetradecyl,
pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl
groups.
[0115] The borated ester can be present from about 0 to about 20,
preferably about 0.1 to about 15, more preferably about 0.3 to
about 10 and even more preferably about 0.5 to about -5 weight
percent of the lubricating oil composition.
[0116] The epoxy compounds useful for preparing the borate ester of
the invention can be represented by the formulae: ##STR7## wherein
R.sup.31 can be an alkyl chain containing 8 to 30, preferably 10 to
26 and even more preferably 12 to 22 carbon atoms; R.sup.32 can be
hydrogen or an alkyl chain containing 1 to 4, preferably 1 to 2
carbon atoms, even more preferably R.sup.32 being hydrogen; and G
can be hydrogen or a halogen, that is, chlorine, bromine, iodine or
fluorine or mixtures thereof, although chlorine is preferred. Even
more preferably G is hydrogen. When G is a halogen, the epoxy
compounds of the invention are epihalohydrin compounds.
[0117] In one embodiment the epoxy compounds of the invention
include commercial mixtures of C.sub.14-C.sub.16 epoxides or
C.sub.14-C.sub.18 epoxides. In one embodiment, the epoxy compounds
of the invention have been purified. Examples of suitable purified
epoxy compounds can include 1,2-epoxydecane, 1,2-epoxyundecane,
1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxybutadecane,
1,2-epoxypenta-decane, 1,2-epoxyhexadecane, 1,2-epoxyheptadecane,
1,2-epoxyoctadecane, 1,2-epoxyhonadecane and 1,2-epoxyicosane.
Preferably purified epoxy compounds include 1,2-epoxytetradecane,
1,2-epoxypentadecane 1,2-epoxyhexadecane 1,2-epoxyheptadecane,
1,2-epoxyoctadecane; and more preferably 1,2-epoxyhexadecane.
[0118] Another group of compounds described as "epoxy compounds or
equivalent" are alcohols and include monohydric alcohols, dihydric
alcohols, trihydric alcohols, higher alcohols (that is, alcohols
containing about 4 or more hydroxy groups) and mixtures thereof,
monohydric alcohols being preferred. Typically the alcohol
compounds contain about 2 to about 30, more preferably about 4 to
about 26 and even more preferably about 6 to about 20 carbon atoms.
The alcohol compounds can include glycerol compounds such as
glycerol monooleate.
Other Performance Additives
[0119] The lubricated part is lubricated using a lubricating oil
composition comprising (a) at least one detergent from component
(b) of the invention; an oil of lubricating viscosity from
component (c) of the invention; (c) optionally a metal hydrocarbyl
dithiophosphate; (d) optionally a borate ester; and (e) other
performance additives.
[0120] The other performance additives selected from the group
consisting of detergents other than those of component (b) of the
invention, metal deactivators, dispersants, antioxidants, antiwear
agents, corrosion inhibitors, antiscuffing agents, extreme pressure
agents, foam inhibitors, demulsifiers, friction modifiers other
than a borate ester, viscosity modifiers, pour point depressants,
fluidity modifiers and seal swelling agents. Typically,
fully-formulated lubricating oil will contain one or more of these
other performance additives.
[0121] The total combined amount of the other performance additives
present can be from about 0 to about 30, preferably about 1 to
about 25, more preferably about 2 to about 20 and even more
preferably about 3 to about 15 weight percent of the lubricating
oil composition. Although one or more of the other performance
additives can be present, it is common for the performance
additives to be present in different amounts relative to each
other.
[0122] Typically antioxidants and/or viscosity modifiers are the
most abundant and account for about 40 or more, preferably about 55
or more, more preferably about 70 or more, even more preferably
about 80 or more and even more preferably about 90 or more wt % of
the other performance additives in the lubricating oil composition.
Typically antioxidants are present in about 2 to about 10 wt % of
the lubricating oil composition, for example, 3 wt %, 4 wt %, 5 wt
% or 6 wt %; Typically viscosity modifiers are present in about 2
to about 15 wt % of the lubricating oil composition, for example, 4
wt %, 5 wt % or 6 wt %, 7 wt % or 8 wt %.
Metal Deactivators
[0123] Metal deactivators can be used to neutralise the catalytic
effect of metal for promoting oxidation in lubricating oil.
Examples of metal deactivators include but are not limited to
derivatives of benzotriazoles, 1,2,4-triazoles, benzimidazoles,
2-alkyldithiobenzimidazoles, 2-alkyldithiobenzothiazoles,
2-(N,N-dialkyldithiocarbamoyl)benzothiazoles,
2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles,
2,5-bis(N,N-dialkyldithiocarbamoyl)-1,3,4-thiadiazoles,
2-alkyldithio-5-mercapto thiadiazoles and mixtures thereof. The
metal deactivator may be used alone or in combination with other
metal deactivators.
[0124] In one embodiment the metal deactivator is a derivative of
benzotriazole. In one embodiment the metal deactivator is a
2,5-bis(alkyl-dithio)-1,3,4-thiadiazole.
[0125] In one embodiment hydrocarbyl benzotriazoles substituted at
positions 4- or 5- or 6- or 7- can be further reacted with an
aldehyde and a secondary amine to form a Mannich product. Examples
of suitable Mannich products include
N,N-bis(heptyl)-ar-methyl-1H-benzotriazole-1-methanamine,
N,N-bis(nonyl)-ar-methyl-1H-benzotriazole-1-methanamine,
N,N-bis(decyl)-ar-methyl-1H-benzotriazole-1-methanamine,
N,N-bis(undecyl)-ar-methyl-1H-benzotriazole-1-methanamine,
N,N-bis(dodecyl)-ar-methyl-1H-benzotriazole-1-methanamine
N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methan-amine and
mixtures thereof. In one embodiment the metal deactivator is
N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methanamine.
[0126] In one embodiment the metal deactivator is a hydrocarbyl
substituted benzotriazole compound. The benzotriazole compounds
with hydrocarbyl substitutions include at least one of the
following ring positions 1- or 2- or 4- or 5- or 6- or 7-. The
hydrocarbyl groups contain 1 to 30, preferably 1 to 15, preferably
1 to 7 carbon atoms, and even more preferably the metal deactivator
is 5-methylbenzotriazole (tolyltriazole).
[0127] In one embodiment, the metal deactivator is a
2,5-bis(alkyl-dithio)-1,3,4-thiadiazole. The alkyl groups of
2,5-bis(alkyl-dithio)-1,3,4-thiadiazole contain 1 to about 30,
preferably about 2 to about 25, more preferably 4 to about 20 and
even more preferably about 6 to about 16 carbon atoms. Examples of
suitable 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles include but are
not limited to 2,5-bis(tert-octyldithio)-1,3,4-thiadiazole
2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-decyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-undecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-tridecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-tetradecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-pentadecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-hexadecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-heptadecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-octadecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-nonadecyldithio)-1,3,4-thiadiazole,
2,5-bis(tert-eicosyldithio)-1,3,4-thiadiazole and mixtures thereof.
Preferably a 2,5-bis(alkyl-dithio)-1,3,4-thiadiazole metal
deactivator can be 2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole or
mixtures thereof.
Detergents
[0128] Detergents other than those of component (b) of the
invention are known and can include neutral or overbased, Newtonian
or non-Newtonian, basic salts of alkali, alkaline earth and
transition metals with one or more of carboxylic acid, phosphorus
acid, mono- and/or di- thiophosphoric acid, saligenins or mixtures
thereof. Commonly used metals include sodium, potassium, calcium,
magnesium lithium or mixtures thereof. Most commonly used metals
include sodium, magnesium and calcium.
Dispersants
[0129] 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 forming metals when added to a lubricant and polymeric
dispersants. Ashless type dispersants are characterised by a polar
group attached to a relatively high molecular 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 in the range 350 to 5000, preferably 500
to 3000. Succinimide dispersants and their preparation are
disclosed, for instance in U.S. Pat. No. 4,234,435.
[0130] In one embodiment the invention further comprises at least
one dispersant derived from polyisobutylene, an amine and zinc
oxide to form a polyisobutylene succinimide complex with zinc. The
polyisobutylene succinimide complex with zinc can be used alone or
in combination with other dispersants.
[0131] Another class of ashless dispersant is Mannich bases.
Mannich dispersants are the reaction products of alkyl phenols in
which the alkyl group contains at least 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines).
[0132] Dispersants can also be post-treated conventional method by
a reaction with any of a variety of agents. Among these are urea,
thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes,
ketones, carboxylic acids, hydrocarbon-substituted succinic
anhydrides, maleic anhydride, nitriles, epoxides, boron compounds,
and phosphorus compounds.
Antiwear Agents
[0133] The lubricating oil composition may additionally contain an
antiwear agent. Useful antiwear agents other than ZDDP include
phosphoric acid esters or salt thereof; phosphites; and
phosphorus-containing carboxylic esters, ethers, and amides or
mixtures thereof.
Antioxidants
[0134] Antioxidants are known materials and include diphenylamines,
sterically hindered phenols, molybdenum dithiocarbamates and
sulphurised olefins.
[0135] Examples of suitable diphenylamine antioxidants include
octyl diphenylamine, nonyl diphenylamine, bis-octyl diphenylamine,
bis-nonyl diphenylamine or mixtures thereof.
[0136] Examples of sterically hindered phenols can 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,
4-butyl-2,6-di-tert-butylphenol 2,6-di-tert-butylphenol,
4-pentyl-2,6-di-tert-butylphenol, 4-hexyl-2,6-di-tert-butylphenol,
4-heptyl-2,6-di-tert-butylphenol,
4-(2-ethylhexyl)-2,6-di-tert-butylphenol,
4-octyl-2,6-di-tert-butylphenol, 4-nonyl-2,6-di-tert-butylphenol,
4-decyl-2,6-di-tert-butylphenol, 4-undecyl-2,6-di-tert-butylphenol,
4-dodecyl-2,6-di-tert-butylphenol,
4-tridecyl-2,6-di-tert-butylphenol,
4-tetradecyl-2,6-di-tert-butylphenol,
3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid butyl ester,
3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid methyl ester,
3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid 2-ethylhexyl
ester and mixtures thereof.
[0137] In one embodiment the sterically hindered phenol is
2,6-di-tert-butylphenol and mixtures thereof. In one embodiment the
sterically hindered phenol is
4-(2-ethylhexyl)-2,6-di-tert-butylphenol and mixtures thereof. In
one embodiment the sterically hindered phenol is
4-dodecyl-2,6-di-tert-butylphenol and mixtures thereof.
[0138] In one embodiment two sterically hindered phenols can be
linked through a bridging group typically located at position 2- or
4- relative to the hydroxyl group. The bridging group can include
--CH.sub.2-- (methylene bridge) or --CH.sub.2OCH.sub.2-- (ether
bridge) or mixtures thereof. Examples of methylene-bridged
sterically hindered phenols include but are not limited to
4,4'-methylenebis(6-tert-butyl-o-cresol),
4,4'-methylenebis(2-tert-amyl-o-cresol),
2,2'-methylenebis(4-methyl-6-tert-butylphenol),
4,4'-methylene-bis(2,6-di-tertbutyl-phenol) and mixtures
thereof.
[0139] Suitable examples of molybdenum dithiocarboamates include
commercial materials sold under the trade names such as Vanlube
822.TM. and Molyvan.TM. A from R. T. Vanderbilt Co., Ltd., and
Adeka Sakura-Lubem S-100 and S-165 and S-600 from Asahi Denka Kogyo
K. K.
[0140] Examples of suitable olefins that can be sulphurised include
propylene, isobutylene, pentene, hexane, heptene, octane, nonene,
decene, undecene, dodecene, undecyl, tridecene, tetradecene,
pentadecene, hexadecene, heptadecene, octadecene, octadecenene,
nonodecene, eicosene or mixtures thereof. In one embodiment,
hexadecene, heptadecene, octadecene, octadecenene, nonodecene,
eicosene or mixtures thereof and their dimers, trimers and
tetramers are especially preferred olefins. Alternatively, the
olefin can be a. Diels-Alder adduct of a diene such as
1,3-butadiene and an unsaturated ester such as butyl (meth)
acrylate.
[0141] Another class of sulphurised olefins include fatty acids and
their esters. The fatty acids are often obtained from vegetable oil
or animal oil; and typically contain 4 to 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. In one embodiment fatty acids and mixed with olefins.
Corrosion Inhibitors
[0142] Corrosion inhibitors can include amine salts of carboxylic
acids such as octylamine octanoate, condensation products of
dodecenyl succinic acid or anhydride and a fatty acid such as oleic
acid with a polyamine, e.g. a polyalkylene polyamine such as
triethylenetetramine, and half esters of alkenyl succinic acids in
which the alkenyl radical contains 8 to 24 carbon atoms with
alcohols such as polyglycols.
Antiscuffing Agents
[0143] The lubricant may also contain an antiscuffing agent.
Antiscuffing agents that decrease adhesive wear are often sulphur
containing compounds. Typically the sulphur containing compounds
include organic sulphides and polysulphides, such as
benzyldisulphide, bis-chlorobenzyl) disulphide, dibutyl
tetrasulphide, di-tertiary butyl polysulphide, sulphurised sperm
oil, sulphurised methyl ester of oleic acid, sulphurised
alkylphenol, sulphurised dipentene, sulphurised terpene,
sulphurised Diels-Alder adducts, alkyl sulphenyl N'N-dialkyl
dithiocarbamates, the reaction product of polyamines with polybasic
acid esters, chlorobutyl esters of 2,3-dibromopropoxyisobutyric
acid, acetoxymethyl esters of dialkyl dithiocarbamic acid and
acyloxyalkyl ethers of xanthogenic acids and mixtures thereof.
Extreme Pressure Agents
[0144] Extreme Pressure (EP) agents that are soluble in the oil
include sulphur and chlorosulphur-containing EP agents, chlorinated
hydrocarbon EP agents, phosphorus EP agents, and mixtures thereof.
Examples of such EP agents include chlorinated wax; organic
sulphides and polysulphides such as benzyldisulphide,
bis-(chlorobenzyl) disulphide, dibutyl tetrasulphide, sulphurised
sperm oil, sulphurised methyl ester of oleic acid, sulphurised
alkylphenol, sulphurised dipentene, sulphurised terpene, and
sulphurised Diels-Alder adducts; phosphosulphurised hydrocarbons
such as the reaction product of phosphorus sulphide with turpentine
or methyl oleate; phosphorus esters such as the dihydrocarbon and
trihydrocarbon phosphites, e.g., dibutyl phosphite, diheptyl
phosphite, dicyclohexyl phosphite, pentylphenyl phosphite;
dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite
and polypropylene substituted phenol phosphite; metal
thiocarbamates such as zinc dioctyldithiocarbamate and barium
heptylphenol diacid; the zinc salts of a phosphorodithioic acid;
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.
Foam Inhibitors
[0145] Foam inhibitors are known and can include organic silicones
such as polyacetates, dimethyl silicone, polysiloxanes,
polyacrylates or mixtures thereof. Examples of foam inhibitors
include poly ethyl acrylate, poly 2-ethylhexylacrylate and poly
vinyl acetate.
Demulsifiers
[0146] Demulsifiers are known and include derivatives of propylene
oxide, ethylene oxide, polyoxyalkylene alcohols, alkyl amines,
amino alcohols, diamines and polyamines reacted sequentially with
ethylene oxide or substituted ethylene oxides. Examples of
demulsifiers include trialkyl phosphates, polyethylene glycols,
polyethylene oxides, polypropylene oxides and (ethylene
oxide-propylene oxide) polymers.
Pour Point Depressants
[0147] Pour point depressants are known and include esters of
maleic anhydride-styrene copolymers, polymethacrylates;
polyacrylates; polyacrylamides; condensation products of
haloparaffin waxes and aromatic compounds; vinyl carboxylate
polymers; and terpolymers of dialkylfumarates, vinyl esters of
fatty acids, ethylene-vinyl acetate copolymers, alkyl phenol
formaldehyde condensation resins, alkyl vinyl ethers and mixtures
thereof.
Friction Modifiers
[0148] Friction modifiers other than a borate ester are known and
can include fatty amines, esters, especially glycerol esters such
as glycerol monooleate, fatty phosphites, fatty acid amides, fatty
epoxides, alkoxylated fatty amines, metal salts of fatty acids,
sulfurized olefins, fatty imidazolines, condensation products of
carboxylic acids and polyalkylene-polyamines, amine salts of
alkylphosphoric acids.
[0149] Viscosity Modifiers
[0150] Viscosity modifiers are known and are typically polymeric
materials including styrene-butadiene rubbers, ethylene-propylene
copolymers, polyisobutenes, hydrogenated styrene-isoprene polymers,
hydrogenated radical isoprene polymers, polymethacrylate acid
esters, polyacrylate acid esters, polyalkyl styrenes, alkenyl aryl
conjugated diene copolymers, polyolefins, polyalkylmethacrylates,
esters of maleic anhydride-styrene copolymers and mixtures
thereof.
[0151] Some polymers can also be described as dispersant viscosity
modifiers (often referred to as DVM) because they also exhibit
dispersant properties. Typically polymers of this type include
polyolefins, for example, ethylene-propylene copolymers that have
been functionalized with the reaction product of maleic anhydride
and an amine. Another type of polymer is a polymethacrylate
functionalised with an amine.
Seal Swelling Agents
[0152] Seal swelling agents are known and are typically esters or
low viscosity mineral oils with high naphthenic or aromatic
content. Esters can be derived from monobasic and dibasic acids
with monoalcohols, or esters of polyols with monobasic esters.
Typically the alcohols contain 8 to 13 carbon atoms. Suitable
examples of mineral oil seal swelling agents include adipates,
azelates, and sebacates. Examples of suitable mineral oil seal
swell agents include Exxon Necton-37 (FN 1380) and Exxon Mineral
Seal Oil (FN 3200).
Fluidity Modifiers
[0153] Fluidity modifier are known and can include Hydrocal-38
which is a product identified as a refined naphthenic oil, 40
Neutral naphthenic oil and a low molecular weight
poly-.alpha.-olefin (Ethylflo.TM. 162).
INDUSTRIAL APPLICATION
[0154] The lubricated part of the present invention are useful in
various lubricants such as greases, gear oils, industrial fluids,
hydraulic fluids, transmission fluids, turbine oils, circulating
oils, fuel oils and engine oils.
[0155] In one embodiment the lubricated part of the invention
provides a method for lubricating an internal combustion engine,
comprising supplying thereto a lubricant comprising the composition
as described herein. The invention is particularly suitable for
diesel fuelled engines, gasoline fuelled engines, natural gas
fuelled engine or a mixed gasoline/alcohol fuelled engine.
[0156] The use of the lubricated part of the invention can impart
at least one property selected from decreased wear, decreased
filter plugging, decreased sludge formation, decreased phosphorus
emissions, decreased sulphur emissions, decreased sulphated ash
formation and mixtures thereof.
[0157] The use of the lubricated part of the invention can decrease
the total sulphur content below about 0.5 wt %, preferably below
about 0.3 wt %, even more preferably below about 0.2 wt % and more
preferably below about 0.15 wt
[0158] The use of the lubricated part of the invention can decrease
the total phosphorus content below about 0.1 wt %, preferably,
below about 0.085 wt %, more preferably below about 0.06 wt %, even
more preferably below about 0.055 wt % and even more preferably
below about 0.05 wt %.
[0159] The use of the lubricated part of the invention can decrease
the sulphated ash content below about 1.5 wt %, preferably below
about 1.1 wt %, more preferably below about 1.0 wt %, even more
preferably below about 0.8 wt % and even more preferably below
about 0.5 wt %.
[0160] The following examples provide an illustration of the
invention. These examples are non exhaustive and are not intended
to limit the scope of the invention.
EXAMPLES
Lubricating Oil Composition A
[0161] A 15W-40 formulation is prepared containing about 15 percent
of 100N API Group XX (ASK INVENTORS) base oil, about 4.05 mm2s-1
(cSt) at 100.degree. C. and about 85 percent of 100N Group XX ASK
INVENTORS) base oil, about 6.5 mm.sup.2s.sup.-1 (cSt) at
100.degree. C. Additionally, about 6.8 wt % of a viscosity modifier
(olefin copolymer), about 0.75 wt % of boron containing friction
modifier, about 4.0 wt % of a sterically hindered phenol of the
antioxidant 3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionic acid
butyl ester, about 10 wt % of polyisobutylene dispersant, about 100
ppm of a commercially available silicone antifoam agent are added
to the lubricant formulation, about 2.1 wt % of magnesium phenate
detergent including diluent oil, about 0.6 wt % of calcium
sulphonate detergent including diluent oil and about 0.6 wt %
polyisobutylene salixarate detergent including diluent oil. The
formulation is used to lubricate valve train components with no
coating.
Lubricating Oil Composition B
[0162] About 100 g of a 15W-40 formulation is prepared containing
about 5 percent of 600N API Group XX (ASK INVENTORS) base oil,
about 12.2 mm2s.sup.-1 (cSt) at 100.degree. C. and about 95 percent
of 100N Group XX ASK INVENTORS) base oil, about 6.5 mm2s.sup.-1
(cSt) at 100.degree. C. Additionally, about 6.8 wt % of a viscosity
modifier (olefin copolymer), about 0.2 wt % of maleic anhydride
styrene copolymer viscosity index improver, about 1.3 wt % of boron
containing friction modifier, about 4.0 wt % of a sterically
hindered phenol antioxidant
3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionic acid butyl ester,
about 10 wt % of polyisobutylene dispersant, about 100 ppm of a
commercially available silicone antifoam agent are added to the
lubricant formulation, about 2.1 wt % of magnesium phenate
detergent including diluent oil, about 1.04 wt % of calcium dodecyl
phenate sulphide detergent and about 0.6 wt % of calcium sulphonate
detergent including diluent oil. The formulation is used to
lubricate valve train components with no coating.
Reference Example M
[0163] A lubricating oil composition A and used to lubricate valve
train components without a coating.
Reference Example N
[0164] A lubricating oil composition B and used to lubricate valve
train components without a coating.
Example 1
[0165] An oil of lubricating viscosity is prepared using the
formulation of "Lubricating Oil Composition A" and used to
lubricate valve train components coated with a commercially
available chromium nitride coating (Balinit.RTM.D) from Balzers
Limited.
Example 2
[0166] An oil of lubricating viscosity is prepared using the
formulation of "Lubricating Oil Composition A" and used to
lubricate the rocker arm is coated with a commercially available
tungsten carbide coating (Balinit.RTM.C) from Balzers Limited.
Example 3
[0167] An oil of lubricating viscosity is prepared using the
formulation of "Lubricating Oil Composition B" and used to
lubricate the rocker arm is coated with a commercially available
chromium nitride coating (Balinit.RTM.D) from Balzers Limited.
Example 4
[0168] An oil of lubricating viscosity is prepared using the
formulation of "Lubricating Oil Composition B" and used to
lubricate valve train components coated with a commercially
available tungsten carbide coating (Balinit.RTM.C) from Balzers
Limited.
Test 1 Cummins M11 Wear Test
[0169] Reference Examples 1 and 2 as well as Examples 1 to 4 are
run in the API CH-4 Cummins M11 Engine test. This test uses a
Cummins.TM. 370-E block engine, which is an electronically governed
in-line 6-cylinder 4-stroke, compression ignition engine. The test
is conducted in two stages, the first about 65 hours and the second
about 20 hours. During the first stage, the engine is over-fuelled
and operated with retarded timing to generate soot at an
accelerated rate. During the second stage the engine is run at
lower speed and higher torque, to induce wear. The crosshead wear,
considered to be representative of valve train wear, is determined
and averaged for 12 crossheads. The valve adjuster wear is averaged
for 12 adjusters. Injector adjuster wear is averaged over six
adjusters. Generally lower weight loss indicates better wear
performance The results obtained are: TABLE-US-00001 Valve Adjuster
weight Injector Adjuster weight Example loss (mg) loss (mg) Example
Reference M 4.1 41.4 Example 1 7.3 39.3 Example 2 4.9 19.8 Example
Reference N 13.5 42.6 Example 3 4.1 38.1 Example 4 3.8 36.1
Test 2 Sludge Test
[0170] The amount of sludge produced is measured by placing oil of
lubricating viscosity in an oil pan and rocker cover and left to
stand for about 6 hours at about 24.degree. C. The sample is then
placed at an angle of about 600 from horizontal for about 8 hours
at about 24.degree. C. The amount of sludge on the oil pan and
rocker cover is in general those deposits that do not drain off,
but which can be removed by wiping. The grading scheme rates the
deposits on the oil pan and rocker cover between 1 and 10, with 10
being completely free of sludge. The results obtained are:
TABLE-US-00002 Example Sludge Rating Example Reference M 7.5
Example 1 7.7 Example 2 7.3 Example Reference N 6.8 Example 3 7.1
Example 4 7.3
Test 3 Filter Plugging
[0171] The test is carried out on the API CH-4 Cummins M11 Engine
test and the Cummins.TM. 370-E block engine. The test measures the
difference in pressure between air leaving a filter at the start
and end of the test. Generally the better results are obtained for
examples with low differences in filter pressure. The results
obtained are: TABLE-US-00003 Difference in Filter Example Pressure
(kPa) Example Reference M 25.3 Example 1 31.6 Example 2 101.1
Example Reference N 74.8 Example 3 86.3 Example 4 13.6
[0172] Overall the examples indicate that the lubricating oils used
in combination with a partial hard surface coating is capable of
providing at least one property selected from decreased wear,
decreased filter plugging, decreased sludge formation, decreased
phosphorus emissions, decreased sulphur emissions, decreased
sulphated ash formation and mixtures thereof.
[0173] While the invention has been explained, it is to be
understood that various modifications thereof will become apparent
to those skilled in the art upon reading the specification.
Therefore, it is to be understood that the invention disclosed
herein is intended to cover such modifications as fall within the
scope of the appended claims.
* * * * *