U.S. patent application number 15/491043 was filed with the patent office on 2018-10-25 for lubricating compositions comprising a volatility reducing additive.
The applicant listed for this patent is SHELL OIL COMPANY. Invention is credited to Richard Thomas DIXON, Adam David MAYERNICK.
Application Number | 20180305633 15/491043 |
Document ID | / |
Family ID | 62200402 |
Filed Date | 2018-10-25 |
United States Patent
Application |
20180305633 |
Kind Code |
A1 |
MAYERNICK; Adam David ; et
al. |
October 25, 2018 |
LUBRICATING COMPOSITIONS COMPRISING A VOLATILITY REDUCING
ADDITIVE
Abstract
A lubricating composition is provided comprising: (i) a base
oil; and (ii) a volatility reducing additive; wherein the
composition has a kinematic viscosity at 100.degree. C. (according
to ASTM D445) of 16.3 mm.sup.2/s or less, a low temperature
cranking viscosity of at most 6200 cP at -35.degree. C. (ASTM
D5293) and a NOACK volatility of at most 15% according to ASTM
D5800B.
Inventors: |
MAYERNICK; Adam David;
(Houston, TX) ; DIXON; Richard Thomas; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHELL OIL COMPANY |
Houston |
TX |
US |
|
|
Family ID: |
62200402 |
Appl. No.: |
15/491043 |
Filed: |
April 19, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2020/02 20130101;
C10M 2215/065 20130101; C10N 2030/10 20130101; C10M 171/00
20130101; C10M 2203/003 20130101; C10M 135/18 20130101; C10M
2215/02 20130101; C10M 2227/066 20130101; C10M 2219/068 20130101;
C10M 2215/28 20130101; C10M 133/04 20130101; C10N 2030/06 20130101;
C10N 2030/74 20200501; C10N 2030/02 20130101; C10N 2040/25
20130101; C10M 169/04 20130101; C10M 2205/173 20130101; C10M
2215/064 20130101 |
International
Class: |
C10M 135/18 20060101
C10M135/18; C10M 133/04 20060101 C10M133/04 |
Claims
1. A lubricating composition comprising: (i) a base oil; (ii)
volatility reducing additives; wherein the volatility reducing
additives comprises a molybdenum based friction modifier and an
aminic antioxidant; and wherein the composition has a kinematic
viscosity at 100.degree. C. (according to ASTM D445) of 16.3 mm2/s
or less, a low temperature cranking viscosity of at most 6200 cP at
-35.degree. C. (ASTM D5293) and a NOACK volatility of at most 15%
according to ASTM D5800B.
2. The lubricating composition according to claim 1, wherein the
composition has a NOACK volatility of at most 12.5% according to
ASTM D5800B.
3. The lubricating composition according to claim 1, wherein the
molybdenum based friction modifier is present in the range of from
0.5 wt. % to 5 wt. % with respect to the total weight of the
lubricating composition.
4. The lubricating composition according to claim 1, wherein the an
aminic antioxidant is present in the range of from 0.5 wt. % to 5
wt. % with respect to the total weight of the lubricating
composition.
5. The lubricating composition according to claim 1, wherein the
base oil comprises one or more Fischer-Tropsch derived base
oils.
6. The lubricating composition according to claim 5, wherein the
base oil comprises 80% or greater of one or more Fischer-Tropsch
derived base oils, by weight of the base oil.
Description
BACKGROUND
[0001] The present invention relates to lubricating compositions
comprising a base oil and a volatility reducing additive for
particular use in the crankcase of an internal combustion engine,
in particular an internal combustion engine used in a passenger
vehicle or light duty van.
[0002] In practice, various lubricating compositions for crankcase
engines are known. A disadvantage of low viscosity crankcase engine
oils is that they they may have undesirably high volatility, in
particular as measured by the ASTM D5800B NOACK volatility
test.
[0003] Attempts have been made to overcome the above problems by
formulating with low volatility base oils, such as Fischer-Tropsch
derived base oils. WO2010020653 discloses the use of
Fischer-Tropsch base oils in lubricating compositions. The
composition of Example 1 of WO2010020653 shows a surprisingly low
NOACK volatility when compared to the composition of Comparative
Example 1 (using a Group III mineral base oil).
[0004] However, for future low viscosity engine oils such as 0W-16
(as per SAE J300 table of engine oil viscosity grades) and lower
viscosities (0W-12, 0W-8, etc), additional benefits beyond those
conferred via the use of Fischer-Tropsch base oils may be
desired.
[0005] It has surprisingly been found that by including certain
lubricant additives in the lubricating formulation the NOACK
volatility can be lowered.
SUMMARY
[0006] According to the present invention, there is provided a
lubricating composition comprising:
[0007] (i) a base oil; and
[0008] (ii) a volatility reducing additive;
wherein the lubricating composition has a kinematic viscosity at
100.degree. C. (according to ASTM D445) of 16.3 mm.sup.2/s or less,
a low temperature cranking viscosity of at most 6200 cP at
-35.degree. C. (ASTM D5293) and a NOACK volatility of at most 15.0%
according to ASTM D5800B.
[0009] According to another aspect of the present invention, there
is provided the use of a volatility reducing additive for reducing
the NOACK volatility of a lubricating composition, in particular
wherein the lubricating composition comprises a Fischer-Tropsch
base oil.
DETAILED DESCRIPTION
[0010] The base oil used in the present invention may conveniently
comprise mixtures of one or more mineral oils and/or one or more
synthetic oils; thus, according to the present invention, the term
"base oil" may refer to a mixture containing more than one base
oil. Mineral oils include liquid petroleum oils and solvent-treated
or acid-treated mineral lubricating oil of the paraffinic,
naphthenic, or mixed paraffinic/naphthenic type which may be
further refined by hydrofinishing processes and/or dewaxing.
[0011] Suitable base oils for use in the lubricating oil
composition of the present invention are Group III mineral base
oils, Group IV poly-alpha olefins (PAOs), Group III Fischer-Tropsch
derived base oils and mixtures thereof.
[0012] By "Group III" and "Group IV" base oils in the present
invention are meant lubricating oil base oils according to the
definitions of American Petroleum Institute (API) for category III
and IV. These API categories are defined in API Publication 1509,
15th Edition, Appendix E, April 2002.
[0013] Fischer-Tropsch derived base oils are known in the art. By
the term "Fischer-Tropsch derived" is meant that a base oil is, or
is derived from, a synthesis product of a Fischer-Tropsch process.
A Fischer-Tropsch derived base oil may also be referred to as a GTL
(Gas-To-Liquids) base oil. Suitable Fischer-Tropsch derived base
oils that may be conveniently used as the base oil in the
lubricating composition of the present invention are those as for
example disclosed in EP 0 776 959, EP 0 668 342, WO 97/21788, WO
00/15736, WO 00/14188, WO 00/14187, WO 00/14183, WO 00/14179, WO
00/08115, WO 99/41332, EP 1 029 029, WO 01/18156 and WO
01/57166.
[0014] Synthetic oils include hydrocarbon oils such as olefin
oligomers (including polyalphaolefin base oils; PAOs), dibasic acid
esters, polyol esters, polyalkylene glycols (PAGs), alkyl
naphthalenes and dewaxed waxy isomerates. Synthetic hydrocarbon
base oils sold by the Shell Group under the designation "Shell
XHVI" (trade mark) may be conveniently used.
[0015] Poly-alpha olefin base oils (PAOs) and their manufacture are
well known in the art. Suitable poly-alpha olefin base oils that
may be used in the lubricating compositions of the present
invention may be derived from linear C.sub.2 to C.sub.32,
preferably C.sub.6 to C.sub.16, alpha olefins. Particularly
preferred feedstocks for said poly-alpha olefins are 1-octene,
1-decene, 1-dodecene and 1-tetradecene.
[0016] Preferably, the base oil as used in the lubricating
composition according to the present invention comprises a
Fischer-Tropsch derived base oil.
[0017] There is a strong preference for using a Fischer-Tropsch
derived base oil over a PAO base oil, in view of the high cost of
manufacture of the PAOs. Thus, preferably, the base oil contains
more than 50 wt. %, preferably more than 60 wt. %, more preferably
more than 70 wt. %, even more preferably more than 80 wt. %, most
preferably more than 90 wt. % Fischer-Tropsch derived base oil.
[0018] The total amount of base oil incorporated in the lubricating
composition is preferably present in an amount in the range of from
60 to 99 wt. %, more preferably in an amount in the range of from
65 to 90 wt. %, and most preferably in an amount in the range of
from 70 to 85 wt. %, with respect to the total weight of the
lubricating composition.
[0019] According to the present invention, the base oil (or base
oil blend) preferably has a kinematic viscosity at 100.degree. C.
of at least 3.0 cSt (according to ASTM D445), preferably between
3.0 and 4.0 cSt.
[0020] The lubricating composition of the present invention further
comprises a volatility reducing additive. As used herein, the term
"volatility reducing additive" pertains to any compound added into
a lubricating composition at low levels (typically 1% or less) that
confers a reduction in NOACK volatility. Some examples of suitable
volatility reducing additives include, but are not necessarily
limited to, an aminic anti-oxidant, molybdenum based friction
modifier, and a combination thereof.
[0021] The volatility reducing additive may be present in the
lubricating composition on its own or as part of an additive
package. The volatility reducing additive is preferably present in
the lubricating composition in an amount in the range of from 0.5
wt. % to 5 wt. %, preferably 0.5 wt. % to 2 wt. %, with respect to
the total weight of the lubricating composition.
[0022] As mentioned above, the lubricating composition according to
the present invention meets certain specific requirements for the
low temperature cranking viscosity at -35.degree. C., the kinematic
viscosity at 100.degree. C. and the NOACK volatility. Typically,
the low temperature cranking viscosity at -35.degree. C. (according
to ASTM D5293) of the lubricating composition is at most 6200
cP.
[0023] Typically, the kinematic viscosity at 100.degree. C.
(according to ASTM D445) of the lubricating composition is at most
16.3 cSt, preferably from 3.8 to 16.3 cSt, and more preferably from
3.8 to 9.3 cSt.
[0024] Typically, the high temperature, high shear viscosity
("HTHS") (according to ASTM D4683) of the lubricating composition
is in the range of from 1.7 to 3.7 mPas, preferably in the range of
from 1.7 to 2.6 mPas.
[0025] Typically, the NOACK volatility (according to ASTM D5800B)
of the lubricating composition is 15.0 wt % or below, preferably
12.5 wt % or below, even more preferably 10.0 wt. % or below.
[0026] The lubricating compositions according to the present
invention may optionally further comprise one or more additives
such as anti-oxidants, anti-wear additives, dispersants,
detergents, overbased detergents, extreme pressure additives,
friction modifiers, viscosity index improvers, pour point
depressants, metal passivators, corrosion inhibitors, demulsifiers,
anti-foam agents, seal compatibility agents and additive diluent
base oils, etc.
[0027] As the person skilled in the art is familiar with the above
and other additives, these are not further discussed here in
detail. Specific examples of such additives are described in for
example Kirk-Othmer Encyclopedia of Chemical Technology, third
edition, volume 14, pages 477-526.
[0028] Optional anti-oxidants that may be conveniently used in
lubricant formulations include phenyl-naphthylamines (such as
"IRGANOX L-06" available from Ciba Specialty Chemicals) and
diphenylamines (such as "IRGANOX L-57" available from Ciba
Specialty Chemicals) as e.g. disclosed in WO 2007/045629 and EP 1
058 720 B1, phenolic anti-oxidants, etc. The teaching of WO
2007/045629 and EP 1 058 720 B1 is hereby incorporated by
reference.
[0029] Anti-wear additives that may be conveniently used include
zinc-containing compounds such as zinc dithiophosphate compounds
selected from zinc dialkyl-, diaryl- and/or
alkylaryl-dithiophosphates, molybdenum-containing compounds,
boron-containing compounds and ashless anti-wear additives such as
substituted or unsubstituted thiophosphoric acids, and salts
thereof. Examples of such molybdenum-containing compounds may
conveniently include molybdenum dithiocarbamates, trinuclear
molybdenum compounds, for example as described in WO 98/26030,
sulphides of molybdenum and molybdenum dithiophosphate.
[0030] Boron-containing compounds that may be conveniently used
include borate esters, borated fatty amines, borated epoxides,
alkali metal (or mixed alkali metal or alkaline earth metal)
borates and borated overbased metal salts.
[0031] The dispersant used is preferably an ashless dispersant.
Suitable examples of ashless dispersants are polybutylene
succinimide polyamines and Mannich base type dispersants.
[0032] The detergent used is preferably an overbased detergent or
detergent mixture containing e.g. salicylate, sulphonate and/or
phenate-type detergents.
[0033] Examples of viscosity index improvers which may conveniently
be used in the lubricating composition of the present invention
include the styrene-butadiene stellate copolymers, styrene-isoprene
stellate copolymers and the polymethacrylate copolymer and
ethylene-propylene copolymers. Dispersant-viscosity index improvers
may be used in the lubricating composition of the present
invention.
[0034] Preferably, the lubricating composition contains at least
0.1 wt. % of a pour point depressant. As an example, alkylated
naphthalene and phenolic polymers, polymethacrylates,
maleate/fumarate copolymer esters may be conveniently used as
effective pour point depressants. Preferably not more than 0.5 wt.
% of the pour point depressant is used.
[0035] Furthermore, compounds such as alkenyl succinic acid or
ester moieties thereof, benzotriazole-based compounds and
thiodiazole-based compounds may be conveniently used in the
lubricating compositions as corrosion inhibitors.
[0036] Compounds which may be conveniently used in the lubricating
compositions of the present invention as seal fix or seal
compatibility agents include, for example, commercially available
aromatic esters.
[0037] The lubricating compositions of the present invention may be
conveniently prepared by admixing the volatility reducing additive,
and any optional additives, with the base oil(s).
[0038] The above-mentioned additives are typically present in an
amount in the range of from 0.01 to 35.0 wt. %, based on the total
weight of the lubricating composition, preferably in an amount in
the range of from 0.05 to 25.0 wt. %, more preferably from 1.0 to
20.0 wt. %, based on the total weight of the lubricating
composition.
[0039] Preferably, the lubricating composition contains from 10 wt.
% to 15 wt. % of an additive package comprising a combination of
additives including anti-oxidants, a zinc-based anti-wear additive,
an ashless dispersant, an overbased detergent mixture, and a
silicone-based anti-foaming agent.
[0040] In another aspect, the present invention provides the use of
a volatility reducing additive to lower NOACK volatility of a
lubricating composition, in particular wherein the lubricating
composition comprises a Fischer-Tropsch derived base oil.
[0041] Also the present invention provides a method of improving
NOACK volatility properties, which method comprises lubricating the
crankcase of an engine, in particular a passenger car motor engine,
with a lubricating composition according to the present
invention.
[0042] The present invention is described below with reference to
the following Examples, which are not intended to limit the scope
of the present invention in any way.
Examples
[0043] Lubricating Oil Compositions
[0044] Various engine oils for use in a crankcase engine were
formulated. Table 1 indicates the properties for the base oil
used.
TABLE-US-00001 TABLE 1 Base oil 1 (GTL 4) Kinematic viscosity at
100.degree. C..sup.1 [cSt] 4.1 VI Index.sup.2 125 NOACK
volatility.sup.3 [wt. %] 12.5 .sup.1According to ASTM D 445
.sup.2According to ASTM D 2270 .sup.3According to ASTM D 5800B
[0045] Table 2 indicates the composition and properties of the
fully formulated engine oil formulations that were tested; the
amounts of the components are given in wt. %, based on the total
weight of the fully formulated formulations.
[0046] All tested formulations contained a combination of a base
oil and additive, wherein the base oil in each case was GTL 4.
[0047] "Base oil 1" was a Fischer-Tropsch derived base oil ("GTL
4") having a kinematic viscosity at 100.degree. C. (ASTM D445) of
approx. 4 cSt (mm.sup.2s.sup.-1). This base oil may be conveniently
manufactured by the process described in e.g. WO-A-02/070631, the
teaching of which is hereby incorporated by reference.
[0048] "Additive A" was a dispersant, Infineum C9280, which is
commercially available from Infineum.
[0049] "Additive B" was an aminic antioxidant, Infineum C9452,
which is commercially available from Infineum.
[0050] "Additive C" was a molybdenum based friction modifier,
Infineum C9455, which is commercially available from Infineum.
[0051] The compositions of Examples 1 to 3 and Comparative Example
1 and 2 were obtained by mixing the base oils with the additive,
where present, using conventional lubricant blending procedures.
The results of NOACK volatility testing via ASTM D5800B are shown
in Table 2.
TABLE-US-00002 TABLE 2 Component Comp. Comp. [wt. %] Ex. 1 Ex. 2
Ex. 1 Ex. 2 Ex. 3 Additive A 0 1.0 0 0 0 Additive B 0 0 0.5 1.5 0
Additive C 0 0 0 0 0.7 GTL 4 100 99.0 99.5 98.5 99.3 Total 100 100
100 100 100 NOACK, %/m 12.5 12.6 11.8 11.6 11.0
DISCUSSION
[0052] As can be learned from Table 2, Examples 1-3, which contain
a volatility reducing additive, have significantly lower NOACK
volatility values than Comparative Examples 1 and 2, which do not
contain a volatility reducing additive. These results are
particularly surprising because each additive included in the
formulations shown for Examples 1-3 is comprised of a concentrate
wherein the additive has been diluted in a base oil with NOACK
volatility of greater than 12.5% as measured by ASTM D5800B, thus
the expectation is that addition of the additives in Examples 1-3
will increase NOACK volatility rather than decrease it.
[0053] An important benefit of the present invention is that for
future low viscosity engine oils such as 0W-16 (as per SAE J300
table of engine oil viscosity grades) and lower viscosities (0W-12,
0W-8, etc), stringent NOACK volatility requirements can be met with
lesser or no need to use (relatively expensive) poly-alpha olefin
(PAO) base oils.
[0054] Given these findings, it is expected that many other
chemistries may impart similar benefits in serving to lower NOACK
volatility, such as known lubricant additive chemistries
(anti-wear, anti-oxidant, viscosity index improver, friction
modifier, detergent, dispersant, pour point depressant, etc) and
any other chemical species that interacts strongly with the oil-air
interface so as to lower the rate of evaporation including but not
limited to surfactants, functionalized polymers, ionic liquids,
nanoparticles, etc.
* * * * *