U.S. patent application number 14/290281 was filed with the patent office on 2014-09-18 for lubricating composition.
This patent application is currently assigned to Shell Oil Company. The applicant listed for this patent is Shell Oil Company. Invention is credited to Adam David Mayernick, Brian Lee Papke.
Application Number | 20140274841 14/290281 |
Document ID | / |
Family ID | 51529864 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140274841 |
Kind Code |
A1 |
Mayernick; Adam David ; et
al. |
September 18, 2014 |
LUBRICATING COMPOSITION
Abstract
A lubricating oil composition comprising: (a) a base oil
composition comprising Fischer-Tropsch derived base oil; and (b) an
organic molybdenum compound; (c) 30 wt % or less solvency booster;
(d) antioxidant selected from aminic antioxidants, phenolic
antioxidants, and mixtures thereof; (e) detergent comprising
alkaline earth metal salicylate. The lubricating oil composition of
the present invention provides improved anti-wear properties, as
well as improved oxidation and improved piston cleanliness
properties.
Inventors: |
Mayernick; Adam David;
(Houston, TX) ; Papke; Brian Lee; (Sugar Land,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shell Oil Company |
Houston |
TX |
US |
|
|
Assignee: |
Shell Oil Company
Houston
TX
|
Family ID: |
51529864 |
Appl. No.: |
14/290281 |
Filed: |
May 29, 2014 |
Current U.S.
Class: |
508/365 |
Current CPC
Class: |
C10N 2020/02 20130101;
C10M 2219/068 20130101; C10M 2207/289 20130101; C10M 2205/173
20130101; C10M 169/04 20130101; C10M 2207/2835 20130101; C10M
2223/045 20130101; C10M 2203/06 20130101; C10N 2030/06 20130101;
C10N 2030/52 20200501; C10M 2215/064 20130101; C10N 2030/04
20130101; C10N 2020/011 20200501; C10N 2040/25 20130101; C10M
2207/262 20130101; C10M 2203/065 20130101; C10N 2030/10 20130101;
C10M 2207/283 20130101; C10M 2207/262 20130101; C10N 2010/04
20130101; C10M 2223/045 20130101; C10N 2010/04 20130101; C10M
2223/045 20130101; C10N 2010/12 20130101; C10M 2219/068 20130101;
C10N 2010/12 20130101; C10M 2223/045 20130101; C10N 2010/12
20130101; C10M 2219/068 20130101; C10N 2010/12 20130101; C10M
2207/262 20130101; C10N 2010/04 20130101; C10M 2223/045 20130101;
C10N 2010/04 20130101 |
Class at
Publication: |
508/365 |
International
Class: |
C10M 141/10 20060101
C10M141/10 |
Claims
1. A lubricating oil composition comprising: (a) a base oil
composition comprising a Fischer-Tropsch derived base oil; and (b)
an organic molybdenum compound; (c) 30 wt % or less solvency
booster; (d) antioxidant selected from aminic antioxidants,
phenolic antioxidants, and mixtures thereof; (e) detergent
comprising alkaline earth metal salicylate.
2. A lubricating oil composition according to claim 1 wherein the
organic molybdenum compound is a sulphur-containing organic
molybdenum compound.
3. A lubricating oil composition according to claim 2 wherein the
sulphur-containing organic molybdenum compound is selected from
molybdenum dithiophosphate, molybdenum dithiocarbamate and mixtures
thereof.
4. A lubricating oil composition according to any of claims 1 to 3
wherein the detergent comprises (i) an alkaline earth metal
salicylate having a TBNE (total base number equivalent, as
determined by ASTM D2896) in the range of from 50 to 150; (ii) an
alkaline earth metal salicylate having a TBNE in the range of from
150 to 250; and (iii) an alkaline earth metal salicylate having a
TBNE in the range of from 250 to 400.
5. A lubricating oil composition according to any of claims 1 to 4
wherein the solvency booster is selected from alkylated
naphthalenes, alkyl benzenes, naphthenics, esters, and mixtures
thereof.
6. A lubricating oil composition according to any of claims 1 to 5
wherein the solvency booster is present at a level of from 1 wt %
to 20 wt %, by weight of the lubricant composition.
7. A lubricating oil composition according to any of claims 1 to 6,
wherein the antioxidant is an aminic antioxidant, preferably a
diphenylamine.
8. A lubricating oil composition according to any of claims 1 to 7
wherein the alkaline earth metal salicylates are calcium
salicylates.
9. A lubricating oil composition according to any of claims 1 to 8
comprising one or more zinc-based anti-wear additives.
10. A lubricating oil composition according to any of claims 1 to 9
wherein the Fischer-Tropsch derived base oil has a kinematic
viscosity at 100.degree. C. of from 1 mm.sup.2/s to 35
mm.sup.2/s.
11. Use of a lubricating oil composition according to any of claims
1 to 10 for providing improved anti-wear properties, in particular
as determined by the HFRR or the ASTM G133 sliding wear test
method.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a lubricating composition,
in particular a lubricating composition having improved anti-wear
performance.
BACKGROUND OF THE INVENTION
[0002] Lubricating oils are used in internal combustion engines,
gearboxes and other mechanical devices to promote smoother
functioning. Internal combustion engine lubricating oils (engine
oils), in particular, must exhibit a high level of performance
under the high-performance, high-output and harsh operating
conditions of internal combustion engines. Various additives such
as anti-wear agents, metal cleaning agents, non-ash powders and
antioxdiants are therefore added to conventional engine oils to
meet such performance demands. The fuel efficiency performance
required of lubricating oils has continued to increase in recent
years, and this has led to application of various high
viscosity-index base oils or friction modifiers. Various friction
modifier/anti-wear additives are known for use in lubricating
compositions for providing acceptable anti-wear performance.
Examples of known anti-wear additives include zinc dithiophosphate
compounds selected from zinc dialkyl-, diaryl- and/or
alkylaryl-dithiophosphates, molybdenum-containing compounds, and
ashless anti-wear additives such as substituted or unsubstituted
thiophosphoric acids, and salts thereof.
[0003] However, as the demand for ever improving lubricating
performance increases, there is a need for developing lubricating
compositions having improved anti-wear performance.
SUMMARY OF THE INVENTION
[0004] According to the present invention there is provided a
lubricating oil composition comprising:
[0005] (a) a base oil composition comprising a Fischer-Tropsch
derived base oil; and
[0006] (b) an organic molybdenum compound;
[0007] (c) 30 wt % or less solvency booster;
[0008] (d) antioxidant selected from aminic antioxidants, phenolic
antioxidants, and mixtures thereof;
[0009] (e) detergent comprising alkaline earth metal
salicylate.
[0010] According to another aspect of the present invention there
is provided the use of a lubricating oil composition comprising:
[0011] (a) a base oil composition comprising Fischer-Tropsch
derived base oil; and [0012] (b) an organic molybdenum compound;
[0013] (c) 30 wt % or less solvency booster; [0014] (d) antioxidant
selected from aminic antioxidants, phenolic antioxidants, and
mixtures thereof; [0015] (e) detergent comprising alkaline earth
metal salicylate; for providing improved anti-wear performance.
[0016] It has surprisingly been found that the combination of a
Fischer-Tropsch derived base oil together with a
molybdenum-containing organic compound in a lubricating composition
also comprising 30 wt % or less solvency booster, antioxidant and
alkaline earth metal salicylate provides improved anti-wear
performance, together with improved oxidation stability and reduced
deposits.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The lubricating composition of the present invention
comprises a base oil composition. The base oil composition
comprises a Fischer-Tropsch derived base oil.
[0018] 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.
[0019] Typically, the aromatics content of a Fischer-Tropsch
derived base oil, suitably determined by ASTM D 4629, will
typically be below 1 wt. %, preferably below 0.5 wt. % and more
preferably below 0.1 wt. %. Suitably, the base oil has a total
paraffin content of at least 80 wt. %, preferably at least 85, more
preferably at least 90, yet more preferably at least 95 and most
preferably at least 99 wt. %. It suitably has a saturates content
(as measured by IP-368) of greater than 98 wt. %. Preferably the
saturates content of the base oil is greater than 99 wt. %, more
preferably greater than 99.5 wt. %. It further preferably has a
maximum n-paraffin content of 0.5 wt. %. The Fischer-Tropsch
derived base oil preferably also has a content of naphthenic
compounds of from 0 to less than 20 wt. %, more preferably of from
0.5 to 10 wt. %.
[0020] Typically, the Fischer-Tropsch derived base oil or base oil
blend has a kinematic viscosity at 100.degree. C. (as measured by
ASTM D 7042) in the range of from 1 to 35 mm.sup.2/s (cSt),
preferably from 1 to 25 mm.sup.2/s (cSt), more preferably from 2
mm.sup.2/s to 12 mm.sup.2/s. Preferably, the Fischer-Tropsch
derived base oil has a kinematic viscosity at 100.degree. C. (as
measured by ASTM D 7042) of at least 2.5 mm.sup.2/s more preferably
at least 3.0 mm.sup.2/s. In one embodiment of the present
invention, the Fischer-Tropsch derived base oil has a kinematic
viscosity at 100.degree. C. of at most 5.0 mm.sup.2/s, preferably
at most 4.5 mm.sup.2/s, more preferably at most 4.2 mm.sup.2/s
(e.g. "GTL 4"). In another embodiment of the present invention, the
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C. of at most 8.5 mm.sup.2/s, preferably at most 8
mm.sup.2/s (e.g. "GTL 8").
[0021] Further, the Fischer-Tropsch derived base oil typically has
a kinematic viscosity at 40.degree. C. (as measured by ASTM D 7042)
of from 10 to 100 mm.sup.2/s (cSt), preferably from 15 to 50
mm.sup.2/s.
[0022] Also, the Fischer-Tropsch derived base oil preferably has a
pour point (as measured according to ASTM D 5950) of below
-30.degree. C., more preferably below -40.degree. C., and most
preferably below -45.degree. C.
[0023] The flash point (as measured by ASTM D92) of the
Fischer-Tropsch derived base oil is preferably greater than
120.degree. C., more preferably even greater than 140.degree.
C.
[0024] The Fischer-Tropsch derived base oil preferably has a
viscosity index (according to ASTM D 2270) in the range of from 100
to 200. Preferably, the Fischer-Tropsch derived base oil has a
viscosity index of at least 125, preferably 130. Also it is
preferred that the viscosity index is below 180, preferably below
150.
[0025] In the event the Fischer-Tropsch derived base oil contains a
blend of two or more Fischer-Tropsch derived base oils, the above
values apply to the blend of the two or more Fischer-Tropsch
derived base oils.
[0026] Preferably, the base oil composition 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, by weight of
the base oil composition. In an especially preferred embodiment not
more than 5 wt. %, preferably not more than 2 wt. %, of the base
oil composition is not a Fischer-Tropsch derived base oil. It is
even more preferred that 100 wt % of the base oil composition is
based on one or more Fischer-Tropsch derived base oils.
[0027] Preferably the base oil composition comprising the
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C. of between 2 and 35 cSt, preferably between 2 and
10.5 cSt (according to ASTM D 445).
[0028] In addition to the Fischer-Tropsch derived base oil, the
lubricating composition may comprise one or more other types of
mineral derived or synthetic base oils, including Group I, II, III,
IV and V base oils according to the definitions of American
Petroleum Institute (API). These API categories are defined in API
Publication 1509, 15th Edition, Appendix E, July 2009.
[0029] The lubricating composition herein may comprise a PAO base
oil in addition to the Fischer-Tropsch base oil. Poly-alpha olefin
base oils (PAOs) and their manufacture are well known in the art.
Preferred 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.
[0030] The total amount of base oil incorporated in the lubricating
composition of the present invention is preferably an amount in the
range of from 60 to 99 wt. %, more preferably an amount in the
range of from 65 to 90 wt. % and most preferably an amount in the
range of from 70 to 85 wt. %, with respect to the total weight of
the lubricating composition.
[0031] Another essential component of the lubricating oil
compositions of the present invention is an organic molybdenum
compound.
[0032] The organic molybdenum compound for use herein may be a
sulphur-containing organic molybdenum compound such as molybdenum
dithiophosphate or molybdenum dithiocarbamate.
[0033] The organic molybdenum compound is present in the
lubricating composition preferably at a level of 0.001% by weight
or greater, more preferably 0.005% by weight or greater, even more
preferably 0.01% by weight of greater, and most preferably 0.02 wt
% by weight or greater, in terms of the amount of elemental
molybdenum based on the total weight of lubricating composition.
The organic molybdenum compound is present in the lubricating
composition preferably at a level of no greater than 1 wt %, more
preferably no greater than 0.2 wt %, even more preferably no
greater than 0.1% by weight, especially no greater than 0.07% by
weight and most preferably no greater than 0.05 by weight, in terms
of amount of elemental molybdenum based on the total weight of
lubricating composition.
[0034] The lubricating composition may comprise a solvency booster.
As used herein, the term "solvency booster" means a component which
enhances the solvency of the Fischer-Tropsch derived base oil, for
example as measured by improvement of deposit reduction properties,
as measured by the TEOST test method (thermo-oxidation engine oil
simulation test according to ASTM D7097-09) and the KHTT test
method (Komatsu Hot Tube Test according to JPI-5S-55-99).
[0035] The solvency booster may be present at a level of 30 wt % or
less, preferably 20 wt % of less, more preferably 15 wt % or less,
by weight of the lubricating oil composition. The solvency booster
may be present at a level of 1 wt % or more, more preferably 3 wt %
or more, even more preferably 5 wt % or more, by weight of the
lubricating oil composition.
[0036] Suitable solvency boosters for use herein are preferably
selected from alkylated aromatic compounds, such as alkylated
naphthalenes, naphthenic base oils and ester base oils, and
mixtures thereof.
[0037] Preferred alkylated aromatic compounds for use as a solvency
booster herein include alkylated benzenes, alkylated anthracenes,
alkylated phenanthrenes, alkylated biphenyls, and alkylated
naphthalenes and mixtures thereof.
[0038] Alkylated naphthalenes may be produced by any suitable means
known in the art, from naphthalene itself or from substituted
naphthalenes which may contain one or more short chain alkyl groups
having up to about eight carbon atoms, such as methyl, ethyl, or
propyl, etc. Suitable alkyl-substituted naphthalenes include
alphamethylnaphthalene, dimethylnaphthalene, and ethylnaphthalene.
Naphthalene itself is especially suitable since the resulting
mono-alkylated products have better thermal and oxidative stability
than the more highly alkylated materials. Suitable alkylated
naphthalene lubricant compositions are described in U.S. Pat. No.
3,812,036, and U.S. Pat. No. 5,602,086. The preparation of
alkylnaphthalenes is further disclosed in U.S. Pat. No.
4,714,794.
[0039] The alkylated aromatic compound for use herein is preferably
selected from alkylbenzene compounds, alkylnaphthalene compounds,
and mixtures thereof. The alkylaromatic component preferably has a
kinematic viscosity at 100.degree. C. in the range of from 3 to 12
mm.sup.2/s, more preferably in the range of from 3.8 to 7
mm.sup.2/s. Preferably the viscosity index of the alkylaromatic
component is above 40, more preferably at or above 70.
[0040] An especially preferred alkylated aromatic compound for use
herein is an alkylnaphthalene compound. Examples of commercially
available alkylnaphthalene compounds are those available from King
Industries under the tradename NA-Lube such as NA-Lube KR 008,
NA-Lube KR019, and the like, and those available from ExxonMobil
under the tradename Mobil MCP.
[0041] Examples of commercially available alkyl benzene include
that available from Formasan under the tradename Fusyn-22, those
available from Janex under the tradename Janex HAL, and those
available from Shreive Chemical Products, Inc. (SCP) under the
tradename ZEROL.
[0042] Suitable naphthenic base oils for use as a solvency booster
herein includes naphthenic base oils having low viscosity index
(VI) (generally 40-80) and a low pour point. Such base oils are
produced from feedstocks rich in naphthenes and low in wax content.
There is no particular limitation on the type of mineral-derived
naphthenic base oil which can be used in the base oil composition
herein. Any mineral-derived naphthenic base oil which is suitable
for use in a lubricating oil composition can be used herein.
[0043] Naphthenic base oils are defined as Group V base oils
according to API.
[0044] Such mineral-derived base oils are obtained by refinery
processes starting from naphthenic crude feeds. Mineral-derived
naphthenic base oils for use herein preferably have a pour point of
below -20.degree. C. and a viscosity index of below 70. Such base
oils are produced from feedstocks rich in naphthenes and low in wax
content. Mineral-derived naphthenic base oils are well known and
described in more detail in "Lubricant base oil and wax
processing", Avilino Sequeira, Jr., Marcel Dekker, Inc, New York,
1994, ISBN 0-8247-9256-4, pages 28-35.
[0045] Methods of manufacture of naphthenic base oils can be found
in "Lubricants and Lubrication (Second, Completely Revised and
Extended Edition)", published by Wiley-VCH Verlag GmbH & Co.
KgaA, Chapter 4, pages 46-48.
[0046] An example of a suitable naphthenic base oil for use as a
solvency booster herein is that commercially available from China
National Petroleum Corporation under the tradename KN4006. Other
examples of suitable naphthenic base oils for use as a solvency
booster herein include those available from Calumet Specialty
Products under the tradenames Hydrocal, Hydrosol and HR Tufflo, and
those commercially available from Nynas Oil Company under the
tradename Nynas.
[0047] Suitable esters for use as a solvency booster herein include
natural and synthetic esters such as diesters and polyol esters. An
example of a suitable ester for use as a solvency booster herein is
the saturated polyol ester commercially available from Croda
International PLC under the tradename Priolube 3970. Other suitable
esters for use as a solvency booster herein include those available
from Oleon under the tradename Radialube, those available from
Emery under the tradename Emery and those available from ExxonMobil
Chemical under the tradename Esterex.
[0048] The lubricating oil compositions of the present invention
comprises a detergent which comprises an alkaline earth metal
salicylate detergent. The lubricating oil compositions of the
present invention preferably comprises from 0.01 wt % to 9 wt %,
more preferably from 1 wt % to 6 wt %, even more preferably from
3.5 wt % to 5.5 wt o, of detergent, by weight of the lubricating
oil composition.
[0049] In preferred embodiments herein, the lubricating oil
compositions of the present invention comprise detergent, wherein
the detergent comprises (i) an alkaline earth metal salicylate
having a TBNE (total base number equivalent, as determined by ASTM
D2896) in the range of from 50 to 150; (ii) an alkaline earth metal
salicylate having a TBN in the range of from 150 to 250; and (iii)
an alkaline earth metal salicylate having a TBN in the range of
from 250 to 400.
[0050] It has been found that this particular combination of
alkaline earth metal salicylates, together with the specified base
oil, organic molybdenum compound, solvency booster and antioxidant
has been found to especially helpful in providing improved
oxidation stability and reduced deposits.
[0051] Suitable alkaline earth metal salicylates include calcium,
magnesium and barium salicylates, and mixtures thereof, preferably
calcium salicylates.
[0052] The level of an alkaline earth metal salicylate having a
TBNE (total base number equivalent, as determined by ASTM D2896) in
the range of from 50 to 150 is preferably in the range of 0.01 wt %
to 5 wt %, more preferably from 1 wt % to 4 wt %, by weight of the
lubricating oil composition.
[0053] The level of an alkaline earth metal salicylate having a TBN
in the range of from 150 to 250 is preferably in the range of 0.01
wt % to 5 wt %, more preferably from 1 wt % to 3 wt %, by weight of
the lubricating oil composition.
[0054] The level of alkaline earth metal salicylate having a TBN in
the range of from 250 to 400 is preferably in the range of 0.01 wt
% to 3 wt %, more preferably from 1 wt % to 2 wt %, by weight of
the lubricating oil composition.
[0055] The lubricating oil compositions of the present invention
comprises one or more anti-oxidants. Suitable anti-oxidants for use
herein include phenolic antioxidants and/or aminic
antioxidants.
[0056] Said antioxidants are preferably present in an amount in the
range of from 0.1 to 5.0 wt. %, more preferably in an amount in the
range of from 0.3 to 3.0 wt. %, and most preferably in an amount of
in the range of from 0.5 to 1.5 wt. %, based on the total weight of
the lubricating oil composition.
[0057] Examples of aminic antioxidants which may be conveniently
used include alkylated diphenylamines,
phenyl-.alpha.-naphthylamines, phenyl-.beta.-naphthylamines and
alkylated .alpha.-naphthylamines.
[0058] Preferred aminic antioxidants include dialkyldiphenylamines
such as p,p'-dioctyl-diphenylamine,
p,p'-di-.alpha.-methylbenzyl-diphenylamine and
N-p-butylphenyl-N-p-'-octylphenylamine, monoalkyldiphenylamines
such as mono-t-butyldiphenylamine and mono-octyldiphenylamine,
bis(dialkylphenyl)amines such as di-(2,4-diethylphenyl)amine and
di(2-ethyl-4-nonylphenyl)amine, alkylphenyl-1-naphthylamines such
as octylphenyl-1-naphthylamine and
n-t-dodecylphenyl-1-naphthylamine, 1-naphthylamine,
arylnaphthylamines such as phenyl-1-naphthylamine,
phenyl-2-naphthylamine, N-hexylphenyl-2-naphthylamine and
N-octylphenyl-2-naphthylamine, phenylenediamines such as
N,N'-diisopropyl-p-phenylenediamine and
N,N'-diphenyl-p-phenylenediamine, and phenothiazines such as
phenothiazine and 3,7-dioctylphenothiazine.
[0059] Preferred aminic antioxidants include those available under
the following trade designations: "Sonoflex OD-3" (ex. Seiko Kagaku
Co.), "Irganox L-57" (ex. Ciba Specialty Chemicals Co.) and
phenothiazine (ex. Hodogaya Kagaku Co.).
[0060] Examples of phenolic antioxidants which may be conveniently
used include C7-C9 branched alkyl esters of
3,5-bis(1,1-dimethyl-ethyl)-4-hydroxy-benzenepropanoic acid,
2-t-butylphenol, 2-t-butyl-4-methylphenol,
2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol,
2,4-dimethyl-6-t-butylphenol, 2-t-butyl-4-methoxyphenol,
3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone,
2,6-di-t-butyl-4-alkylphenols such as 2,6-di-t-butylphenol,
2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol,
2,6-di-t-butyl-4-alkoxyphenols such as
2,6-di-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-ethoxyphenol,
3,5-di-t-butyl-4-hydroxybenzylmercaptooctylacetate,
alkyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionates such as
n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate,
n-butyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and
2'-ethylhexyul-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate,
2,6-d-t-butyl-.alpha.-dimethylamino-p-cresol,
2,2'-methylene-bis(4-alkyl-6-t-butylphenol) such as
2,2'-methylenebis(4-methyl-6-t-butylphenol, and
2,2-methylenebis(4-ethyl-6-t-butylphenol), bisphenols such as
4,4'-butylidenebis(3-methyl-6-t-butylphenol,
4,4'-methylenebis(2,6-di-t-butylphenol),
4,4'-bis(2,6-di-t-butylphenol), 2,2-(di-p-hydroxyphenyl)propane,
2,2-bis(3,5-di-t-butyl-4-hydroxyphenyl)propane,
4,4'-cyclohexylidenebis(2,6-t-butylphenol),
hexamethyleneglycol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],
triethyleneglycolbis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate],
2,2'-thio-[diethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],
3,9-bis{1,1-dimethyl-2-[3-(3-t-butyl-4-hydroxy-5-methyl-phenyl)propionylo-
xy]ethyl}2,4,8,10-tetraoxaspiro[5,5]undecane,
4,4'-thiobis(3-methyl-6-t-butylphenol) and
2,2'-thiobis(4,6-di-t-butylresorcinol), polyphenols such as
tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane,
1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane,
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene,
bis-[3,3'-bis(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol
ester,
2-(3',5'-di-t-butyl-4-hydroxyphenyl)methyl-4-(2'',4''-di-t-butyl-3''-hydr-
oxyphenyl)methyl-6-t-butylphenol and
2,6-bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol, and
p-t-butylphenol-formaldehyde condensates and
p-t-butylphenol-acetaldehyde condensates.
[0061] Preferred phenolic antioxidants include those available
under the following trade designations: "Irganox L-135" (ex. Ciba
Specialty Chemicals Co.), "Yoshinox SS" (ex. Yoshitomi Seiyaku
Co.), "Antage W-400" (ex. Kawaguchi Kagaku Co.), "Antage W-500"
(ex. Kawaguchi Kagaku Co.), "Antage W-300" (ex. Kawaguchi Kagaku
Co.), "Irganox L-109" (ex. Ciba Speciality Chemicals Co.), "Tominox
917" (ex. Yoshitomi Seiyaku Co.), "Irganox L-115" (ex. Ciba
Speciality Chemicals Co.), "Sumilizer GA80" (ex. Sumitomo Kagaku),
"Antage RC" (ex. Kawaguchi Kagaku Co.), "Irganox L-101" (ex. Ciba
Speciality Chemicals Co.), "Yoshinox 930" (ex. Yoshitomi Seiyaku
Co.).
[0062] The lubricating oil composition of the present invention may
comprise mixtures of one or more phenolic antioxidants with one or
more aminic antioxidants. In addition to the components mentioned
above, the lubricating composition according to the present
invention may further comprise one or more additional additives
such as anti-wear additives, anti-oxidants, dispersants,
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.
[0063] As the person skilled in the art is familiar with the above
and other additives, these are not further discussed here in
detail.
[0064] Specific examples of such additives are described in for
example Kirk-Othmer Encyclopedia of Chemical Technology, third
edition, volume 14, pages 477-526.
[0065] 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 0.1 to
20.0 wt. %, based on the total weight of the lubricating
composition.
[0066] The lubricating composition may also comprise a viscosity
modifier, preferably at a level of 30 wt % or less, based on the
total weight of the lubricating composition. In one embodiment, the
lubricating composition comprises from 20 wt % to 30 wt % of
viscosity modifier. In another embodiment, the lubricating
composition comprises 20 wt % or less of viscosity modifier. In a
preferred embodiment of the present invention, the lubricating
composition is essentially free of viscosity modifier. In a
particularly preferred embodiment of the present invention, the
lubricating composition comprises 0 wt % of a viscosity
modifier.
[0067] Examples of viscosity index improvers include copolymers of
alpha-olefins and dicarboxylic acid esters such as those described
in U.S. Pat. No. 4,931,197. Commercially available copolymers of
alpha-olefins and dicarboxylic acid diesters include the Ketjenlube
polymer esters available from Italmatch (and previously Akzo Nobel
Chemicals). Other suitable examples of viscosity index improvers
are polyisobutylenes; commercially available polyisobutylenes
include the Oloa (RTM) products available from Chevron Oronite.
[0068] Further examples of viscosity index improvers which may
conveniently be used in the lubricating compositions of the present
invention include the styrene-butadiene stellate copolymers,
styrene-isoprene stellate copolymers and the polymethacrylate
copolymers and ethylene-propylene copolymers (also known as olefin
copolymers) of the crystalline and non-crystalline type.
[0069] Suitable olefin copolymers include those commercially
available from Chevron Oronite Company LLC under the trade
designation "PARATONE (RTM)" (such as "PARATONE (RTM) 8921" and
"PARATONE (RTM) 8941"); those commercially available from Afton
Chemical Corporation under the trade designation "HiTEC (RTM)"
(such as "HiTEC (RTM) 5850B"); and those commercially available
from The Lubrizol Corporation under the trade designation "Lubrizol
(RTM) 7067C". Suitable polyisoprene polymers include those
commercially available from Infineum International Limited, e.g.
under the trade designation "SV200". Suitable diene-styrene
copolymers include those commercially available from Infineum
International Limited, e.g. under the trade designation "SV
260".
[0070] In addition to the organic molybdenum compound, the
compositions herein may include one or more further anti-wear
additives. Suitable anti-wear additives for use herein include zinc
dithiophosphate compounds selected from zinc dialkyl-, diaryl-
and/or alkylaryl-dithiophosphates, and ashless anti-wear additives
such as substituted or unsubstituted thiophosphoric acids, and
salts thereof.
[0071] Examples of ashless thiophosphates are known in the art.
These compounds are metal-free organic compounds. Suitable ashless
thiophosphates for use in the lubricating oil composition of the
present invention may include esters and/or salts of thiophosphoric
acids, and substituted thiophosphoric acids. Preferably, the
ashless thiophosphates are substituted by one or more hydrocarbyl
groups which hydrocarbyl groups can optionally contain an acid, a
hydroxy and/or an ester group. The hydrocarbyl moiety preferably is
an alkyl group containing up to 12 carbon atoms. The
hydrocarbyl-substituted thiophosphate preferably contains 2 or 3
hydrocarbyl groups, or is a mixture of thiophosphates containing 2
and 3 hydrocarbyl groups.
[0072] The ashless thiophosphates can contain any number of sulphur
atoms directly linked to the phosphorus atom. Preferably, the
thiophosphates are monothiophosphates and/or dithiophosphates.
[0073] Examples of ashless thiophosphates which may be conveniently
used in the lubricating oil composition of the present invention
are described in EP-A-0375324 , U.S. Pat. No. 5,922,657, U.S. Pat.
No. 4,33,3841 and U.S. Pat. No. 5,093,016 and may be conveniently
made according to the methods described therein.
[0074] Examples of commercially available ashless thiophosphates
that may be conveniently used in the lubricating oil composition of
the present invention include those available from Ciba Specialty
Chemicals under the trade designations "IRGALUBE L-63" and
"IRGALUBE 353" and that available from Lubrizol under the trade
designation "LZ 5125".
[0075] In a preferred embodiment, the lubricating composition
comprises one or more anti-wear additives, preferably one or more
zinc-based anti-wear additives, selected from one or more zinc
dithiophosphates. The or each zinc dithiophosphate may be selected
from zinc dialkyl-, diaryl- or alkylaryl-dithiophosphates.
[0076] Examples of zinc dithiophosphates which are commercially
available include those available from Lubrizol Corporation under
the trade designations "Lz 677A", "Lz 1095", "Lz 1097", "Lz 1370",
"Lz 1371", "Lz 1373" and "Lz 1395", those available from Chevron
Oronite under the trade designations "OLOA 260", "OLOA 262", "OLOA
267" and "OLOA 269R", and those available from Afton Chemical under
the trade designation "HITEC 7169" and "HITEC 7197".
[0077] Preferably, the lubricating composition according to the
present invention comprises a phosphorus containing compound,
preferably selected from the group consisting of phosphonates,
phosphates, phosphites, phosphorothionates and dithiophosphates,
and combinations thereof. Examples of commercially available
dithiophosphates and phosphates are "IRGALUBE 63" and IRGALUBE
349'', respectively, both available from Ciba Specialty
Chemicals.
[0078] The lubricating oil composition of the present invention has
a kinematic viscosity at 40.degree. C. in the range of from 2
mm.sup.2/s to 220 mm.sup.2/s, preferably in the range of from 32
mm.sup.2/s to 220 mm.sup.2/s.
[0079] The lubricating compositions of the present invention may be
conveniently prepared by admixing the one or more additives with
the base oil(s).
[0080] The lubricating composition according to the present
invention may be used in various applications, such as in internal
combustion engines (as an engine oil), as a transmission oil, a
grease, a hydraulic oil, an industrial gear oil, a turbine oil, a
compressor oil, and the like.
[0081] In another aspect the present invention provides a method
for improving anti-wear properties, which method comprises
lubricating with a lubricating composition according to the
invention. In another aspect, the present invention provides the
use of a lubricating composition as described herein, for improving
anti-wear properties (in particular as determined by ASTM G133
and/or the HFRR test method described hereinbelow).
[0082] 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
Lubricating Oil Compositions
[0083] Various combinations of additives, base oils and friction
modifiers were combined together to produce lubricating oil
compositions. Table 1 shows the properties of the base oils. Table
2 indicates the amounts of additives, base oils and friction
modifiers incorporated into the respective formulations; the
amounts are given in wt. %, based on the total weight of the
lubricating composition.
[0084] "Base oil 1" (or "B01" or "GTL 4") was a Fischer-Tropsch
derived base oil having a kinematic viscosity at 100.degree. C.
(ASTM D445) of approximately 3.89 cSt (M.sup.2 s.sup.-1). Base oil
1 may be conveniently manufactured by the process described in e.g.
WO-A-02/070631, the teaching of which is hereby incorporated by
reference.
[0085] "Base oil 2" (or "B02") was a commercially available Group
III base oil having a kinematic viscosity at 100.degree. C. (ASTM
D445) of approximately 4.3 cSt. Base oil 2 is commercially
available from e.g. SK Energy (Ulsan, South Korea) under the trade
designation "Yubase 4".
TABLE-US-00001 TABLE 1 Base oil 1 Base oil 2 (GTL 4) (Yubase 4)
Kinematic viscosity at 40.degree. C..sup.1 [cSt] 16.91 19.49
Kinematic viscosity at 100.degree. C..sup.1 [cSt] 3.89 4.3 VI
Index.sup.2 127 126 Pour point.sup.3 [.degree. C.] -39 -18 Noack
volatility.sup.4 [wt. %] 11.2 14.2 Saturates.sup.5 [wt. %] 99.2
99.3 Tertiary Carbon, %.sup.6 18.1 n.d. Secondary Carbon, %.sup.6
66.7 n.d. Primary Carbon, %.sup.6 14.3 n.d. Epsilon carbon content,
%.sup.6 12.1 n.d. n- and iso- paraffins.sup.7 92.35 n.d.
Mono-naphthenics.sup.7 6.85 n.d. di- and poly- naphthenics.sup.7
0.87 n.d. Aromatics.sup.5 0.5 n.d. Dynamic viscosity at -20.degree.
C..sup.8 [cP] n.d. 713 Dynamic viscosity at -25.degree. C..sup.8
[cP] n.d. 931 Dynamic viscosity at -30.degree. C..sup.8 [cP] 948
n.d. Dynamic viscosity at -35.degree. C..sup.8 [cP] 1580 n.d.
.sup.1According to ASTM D 445 .sup.2According to ASTM D 2270
.sup.3According to ASTM D 5950 .sup.4According to CEC
L-40-A-93/ASTM D 5800 .sup.5According to IP 368 (modified)
.sup.6According to 13C NMR .sup.7According to FIMS .sup.8According
to ASTM D 5293 n.d. = not determined
HFFR Test
[0086] In order to measure the friction properties of the various
lubricating compositions set out in Table 2, the lubricating
compositions were subjected to the HFRR (high frequency
reciprocating rig) test method as described in: Korcek, S., Jensen,
R.K., Johnson, M.D., Sorab, J. "Fuel Efficient Engine Oils,
Additive Interactions, Boundary Friction, and Wear." Lubrication at
the Frontier 1999, 13-24.
[0087] Improved friction properties (friction reduction) are
evidenced by lower HFRR measured friction coefficients.
Sliding Wear Test Method
[0088] In order to measure the anti-wear properties of the various
lubricating compositions set out in Table 2, the lubricating
compositions were subjected to the sliding wear test method as per
ASTM G133. Improved anti-wear properties are evidenced by a lower
wear volume.
[0089] Table 2 lists additives and treat rates used in each
formulation. Table 3 lists the HFRR measured friction coefficients
and ASTM G133 wear volumes for each formulation tested.
TABLE-US-00002 TABLE 2 Concen- Additive tration Component Tradename
Type (wt %) A1 Perfad FM-3338.sup.1 Amide friction modifier 1 A2
Adeka FM-926.sup.2 Amine friction modifier 1 A3 Sakura Lube
S-515.sup.2 Molybdenum 1 dialkyldithiocarbamate A4 Synative
ES-2421.sup.3 Glycerol mono-oleate 1 A5 Infineum C9455.sup.4
Molybdenum 1 dialkyldithiocarbamate A6 Molyvan 822.sup.5 Molybdenum
1 dialkyldithiocarbamate A7 Priolube 3970.sup.1 Ester 10 A8 Irganox
L-57.sup.6 Diphenylamine 0.5 A9 Infineum M7102.sup.4 Calcium
alkylsalicylate 1 A10 Infineum M7121.sup.4 Calcium alkylsalicylate
2 A11 Infineum M7125.sup.4 Calcium alkylsalicylate 0.5 A12 Infineum
C9417.sup.4 Primary/secondary ZDDP 1 mixture In Table 2, the
components marked with superscripts 1-6 are supplied by the
following suppliers: .sup.1. supplied by Uniqema .sup.2. supplied
by Adeka Corp. .sup.3. supplied by Cognis Corp. .sup.4. supplied by
Infineum USA L.P. .sup.5. supplied by R. T. Vanderbilt Co., Inc.
.sup.6. supplied by BASF
TABLE-US-00003 TABLE 3 HFRR Average .mu..sub.F ASTM G133 Wear
Volume (.mu.m.sup.3) Example Additive GTL 4 Yubase 4 GTL 4 Yubase 4
1* A1 0.122 0.124 522467 1170350 2* A1 + A7 + A8 + A9 + A10 + A11 +
A12 0.104 0.111 856917 984883 3* A2 0.111 0.121 3569250 312391 4*
A2 + A7 + A8 + A9 + A10 + A11 + A12 0.093 0.112 2404658 1516083 5
A3 0.068 0.080 1143433 2369933 6 A3 + A7 + A8 + A9 + A10 + A11 +
A12 0.097 0.105 1333083 738367 7* A4 0.077 0.073 258258 188833 8*
A4 + A7 + A8 + A9 + A10 + A11 + A12 0.090 0.096 1091300 849683 9 A5
0.124 0.117 Not measured Not measured 10 A5 + A7 + A8 + A9 + A10 +
A11 0.131 0.115 115250 371583 11 A5 + A7 + A8 + A9 + A10 + A11 +
A12 0.073 0.084 199333 300750 12 A6 0.231 0.233 Not measured Not
measured 13 A6 + A7 + A8 + A9 + A10 + A11 0.137 0.136 251850 493283
14 A6 + A7 + A8 + A9 + A10 + A11 + A12 0.104 0.086 293333 759225
*Comparative Example
Discussion
[0090] The friction and wear performance of both GTL-based and
mineral-based formulations is comparable, with the exception of
formulations containing organic molybdenum-based friction modifiers
(Examples 5, 10, 11, 13, 14) where, surprisingly, a trend towards
lower wear is demonstrated in GTL.
[0091] The results presented herein demonstrate that formulations
containing GTL base oil, organic molybdenum-based friction modifier
and the indicated additives, namely, anti-oxidant, detergent, and
solvency booster/co-solvent, permit improved wear protection (lower
wear scars and lower wear volume) compared with mineral base
oil-based formulations.
* * * * *