Note: Descriptions are shown in the official language in which they were submitted.
'A 02781880 2012-115-24
WO 2011/066242 PCT/US2010/057709
TITLE
Lubricating Composition Containing Viscosity Modifier Combination
FIELD OF INVENTION
[0001] The present invention relates to a lubricating composition
containing
(a) an oil of lubricating viscosity, (b) a star polymer and (c) a
substantially linear
polymer with a weight average molecular weight of 45,000 or less. The
invention
further provides a method of lubricating a mechanical device, typically a
manual
transmission with the lubricating composition. The invention further provides
for the use of the lubricating composition to provide a number of benefits
including lower operating temperatures and fuel economy.
BACKGROUND OF THE INVENTION
[0002] Viscosity index improvers are known to be added to lubricating
oil
compositions to improve the viscosity index of the lubricant. Typical
viscosity
index improvers include polymers of methacrylates, acrylates, olefins (such as
copolymers of alpha-olefins and maleic anhydride and esterified derivatives
thereof), or maleic anhydride-styrene copolymers, and esterified derivatives
thereof. The viscosity index improvers tend to incorporate ester functional
groups
in pendant/grafted/branched groups. The ester functional groups may be derived
from linear alkyl alcohols with 1 to 40 carbon atoms. Recent attempts have
been
made to produce viscosity index improvers from copolymers of alpha-olefins.
However, such viscosity index improvers have poor shear stability, too high a
viscosity at low temperature, poor fuel economy, and poor non-dispersant
cleanliness.
[0003] In addition, lubricants capable of performing at lower viscosity
(in, for
instance, driveline devices) typically provide increased fuel economy (thus
improving corporate average fuel efficiency (CAFE), NEDC (European Driving
Cycle), or FTP-75 (Federal Test Procedure), or Japanese test cycle (JC-08)).
Conversely, higher viscosity fluids contribute to elevated gear and
transmission
operating temperatures, which are believed to reduce fuel economy and diminish
durability.
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[0004] International publication WO 2007/127660 discloses a lubricating
composition containing a star polymer, a phosphorus-containing compound and
an extreme pressure agent.
[0005] International publications W02006/047398 and W02006/047393:
W02006/047398 discloses that the star polymer may be derived from atom
transfer radical polymerisation (ATRP), nitroxide mediated polymerisation,
anionic polymerisation and reversible addition fragmentation (RAFT).
W02006/047393 discloses lubricating compositions having linear and star
poly(meth)acrylates derived from RAFT polymerisation.
[0006] International Patent Application PCT/US2009/052028 discloses a
lubricating composition containing a copolymer comprising units derived from
monomers (i) an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid
or
derivatives thereof esterified with a primary alcohol branched at the 0- or
higher
position, wherein the copolymer, prior to esterification has a reduced
specific
viscosity of up to 0.08.
[0007] US Patent Application 2008/0085847 discloses a lubricating oil
composition comprising a major amount of oil of lubricating viscosity, and a
viscosity index (VI) improver composition comprising a first polymer
comprising
an amorphous ethylene-cc olefin copolymer or ethylene-cc-olefin-diene
terpolymer
having a crystallinity of not greater than about 1.0%; and a second polymer
comprising a star polymer, the arms of which are derived from diene, and
optionally vinyl aromatic hydrocarbon monomer, wherein the star polymer has a
Shear Stability Index (SSI) of from about 1% to about 35% (30 cycle).
SUMMARY OF THE INVENTION
[0008] The inventors of this invention have discovered that a lubricating
composition, method and use as disclosed herein is capable of providing at
least
one of improved oxidative stability, reduced mechanical device operating
temperatures, increased mechanical device durability, improved shear stability
index, improved viscosity index, improved low temperature viscometrics and
improved high temperature viscometrics.
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[0009] In one embodiment the invention provides a lubricating
composition
comprising (a) an oil of lubricating viscosity, (b) a star polymer, and (c) a
substantially linear polymer with a weight average molecular weight of 45,000
or less,
or 35,000 or less, or 25,000 or less, or 8000 to 25,000, or 12,000 to 20,000.
[0010] The substantially linear polymer may have a shear stability index of
less
than 25 (or 15 or less, or 10 or less, or 0 to 10, or 0 to 5) as measured by
procedure
described in CEC test CEC-L-45-99 entitled "Viscosity Shear Stability of
Transmission Lubricants (Taper Roller Bearing Rig)" or test method DIN 51350-6-
KRL/C
[0011] In one embodiment the invention provides a lubricating composition
comprising (a) an oil of lubricating viscosity, (b) a star polymer, and (c) a
substantially linear polymethacrylate polymer with a weight average molecular
weight
of 45,000 or less, or 35,000 or less, or 25,000 or less, or 8000 to 25,000, or
12,000
to 20,000.
[0012] In one embodiment the invention provides a lubricating composition
comprising (a) an oil of lubricating viscosity, (b) a star polymer, and (c) a
copolymer
comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically
unsaturated carboxylic acid or derivatives thereof esterified with an alcohol.
[0013] In one embodiment the invention provides a lubricating
composition
comprising (a) an oil of lubricating viscosity, (b) a star polymer, and (c) a
copolymer
comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically
unsaturated carboxylic acid or derivatives thereof esterified with a primary
alcohol branched at the 13- or higher position, wherein the copolymer, prior
to
esterification has a reduced specific viscosity of up to 0.2, or up to 0.15,
or up to
0.10, or typically up to 0.08.
[0014] In one embodiment the invention provides a lubricating
composition
comprising:
(a) an oil of lubricating viscosity,
(b) a star polymer, wherein the star polymer may be a polymethacrylate or
polyacrylate (typically a polymethacrylate), the star polymer may be derived
from a monomer composition comprising:
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(i) 50 wt % to 100 wt % (or 65 wt % to 95 wt %) of an alkyl
methacrylate, wherein the alkyl group of the methacrylate has 10 to 30, or 10
to
20, or 12 to 18, or 12 to 15 carbon atoms;
(ii) 0 wt % to 40 wt % (or 5 wt % to 30 wt %) of an alkyl
methacrylate, wherein the alkyl group of the methacrylate has 1 to 9, or 1 to
4
carbon atoms (for example methyl, butyl, or 2-ethylhexyl); and
(iii) 0 wt % to 10 wt % (or 0 wt % to 5 wt %, or 0.1 to 2 wt %) of a
dispersant monomer (may be referred to as either oxygen-containing compound,
or nitrogen-containing monomer and typically nitrogen-containing monomer);
and
(c) copolymer comprising units derived from monomers (i) an a¨olefin
and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof
esterified with a primary alcohol branched at the 13- or higher position,
wherein
the copolymer, prior to esterification has a reduced specific viscosity of up
to
0.2, or up to 0.15, or up to 0.10, typically up to 0.08.
[0015] In one embodiment the invention provides a lubricating
composition
comprising an oil of lubricating viscosity, a star polymer and a copolymer
comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically
unsaturated carboxylic acid or derivatives thereof esterified with a primary
alcohol branched at the 13- or higher position, wherein the copolymer is an
interpolymer, and wherein the interpolymer has a reduced specific viscosity
(prior to esterification) of up to 0.08, or 0.02 to 0.08 (or 0.02 to 0.07,
0.03 to
0.07 or 0.04 to 0.06).
[0016] The copolymer comprising units derived from monomers (i) an a-
olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives
thereof
esterified with a primary alcohol branched at the p- or higher position may be
defined in terms of weight average molecular weight or by RSV. Typically the
weight average molecular weight is measured on the final esterified copolymer,
optionally capped with an amine. The weight average molecular weight may be
5000 to 35,000 (approximately 0.15 RSV), or 5000 to 20,000, or 13,000 to
18,000.
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[0017] The
copolymer reduced specific viscosity (RSV) is measured by the
formula RSV = (Relative Viscosity ¨ 1)/Concentration, wherein the relative
viscosity is determined by measuring, by means of a dilution viscometer, the
viscosity of a solution of 1.6 g of the copolymer in 100 cm3 of acetone and
the
viscosity of acetone at 30 C. A more detailed description of RSV is provided
below. The RSV is determined for the copolymer of an a¨olefin and (ii) an
ethylenically unsaturated carboxylic acid or derivatives thereof before
esterification with the primary alcohol branched at the p- or higher position.
[0018] In
different embodiments the primary alcohol branched at the 0- or
higher position may have at least 12 (or at least 16, or at least 18 or at
least 20)
carbon atoms. The number of carbon atoms may range from at least 12 to 60, or
at least 16 to 30.
[0019] In one
embodiment the invention provides a lubricating composition
comprising an oil of lubricating viscosity, a star polymer and a copolymer
comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically
unsaturated carboxylic acid or derivatives thereof esterified with a primary
alcohol branched at the p- or higher position, wherein the copolymer may be an
interpolymer, and wherein the interpolymer has a reduced specific viscosity of
up
to 0.08, or 0.02 to 0.08 (or 0.02 to 0.07, 0.03 to 0.07 or 0.04 to 0.06).
[0020] In one embodiment the copolymer comprising units derived from
monomers (i) an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid
or
derivatives thereof esterified with a primary alcohol branched at the 13- or
higher
position described above further comprises units from a monomer having at
least
one of an ester group and a nitrogen containing group (such as amino-, amido-
and/or imido- group), typically sufficient to provide 0.01 wt % to 1.5 wt %
(or 0.02
wt % to 0.75 wt %, or 0.04 wt % to 0.25 wt %) nitrogen to the copolymer.
[0021] In one
embodiment the invention provides for a method of lubricating a
mechanical device comprising supplying to said mechanical device (typically a
driveline device) a lubricating composition as disclosed herein. In one
embodiment the mechanical device may be a manual transmission.
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[0022] In one embodiment the invention provides for the use of a
lubricating
composition as described herein to provide a lubricant (typically a manual
transmission lubricant) with at least one (or at least two, or up to all) of
acceptable
or improved shear stability, acceptable or improved viscosity index control,
acceptable
or improved low temperature viscosity, acceptable or improved fuel economy,
and
acceptable or improved device operating temperatures. Typically the lubricant
may be
used in a driveline device such as a manual transmission.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention provides a lubricating composition, method
and
use as disclosed herein.
Star Polymer
[0024] The lubricating composition of the invention contains a star
polymer
(or the star polymer may also be referred to as a radial polymer). The star
polymer may be present in the compositions described herein at 0.1 wt % to 30,
or 0.1 wt % to 20 wt %, wt %, or 2 wt % to 30 wt %, or 5 wt % to 20 wt %, or 8
wt % to 15 wt %. The star polymer may also be present at 0.2 wt % to 15 wt %,
or 0.5 wt % to 10 wt % , or 1 wt % to 8 wt % of the lubricating composition.
[0025] A detailed description of the star polymer disclosed herein may
also be
described in WO 2007/127660 (published on 8 November 2007, by Baker et al.
and assigned to The Lubrizol Corporation), paragraphs [0021] to [0061]. Baker
discloses composition and methods of preparation of a variety of star
polymers.
[0026] In one embodiment the star polymer may be a polymer derived from
greater than 50 wt % or more of a non-diene monomer.
[0027] In different embodiments the star polymer may contain greater
than 50
wt %, or 55 wt % or more, or 70 wt % or more, or 90 wt % or more, or 95 wt %
or
more, or 100 wt % of a non-diene monomer (that is to say, non-diene monomer
units
or units derived from polymerisation of one of more non-diene monomers).
Examples
of diene monomers include 1,3-butadiene or isoprene. In contrast, examples of
a non-
diene of the present invention may include styrene, methacrylates, acrylates,
or
mixtures thereof. In one embodiment the star polymer may be a polymer derived
from methacrylates, or mixtures thereof.
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[0028] As described hereinafter the molecular weight of the viscosity
modifier has been determined using known methods, such as GPC analysis using
polystyrene standards. Methods for determining molecular weights of polymers
are well known. The methods are described for instance: (i) P.J. Flory,
"Principles of
star polymer Chemistry", Cornell University Press 91953), Chapter VII, pp 266-
315;
or (ii) "Macromolecules, an Introduction to star polymer Science", F. A. Bovey
and F.
H. Winslow, Editors, Academic Press (1979), pp 296-312. As used herein the
weight
average and number average molecular weights of the polymers of the invention
are
obtained by integrating the area under the peak corresponding to the star
polymer of
the invention, which is normally the major high molecular weight peak,
excluding
peaks associated with diluents, impurities, uncoupled star polymer chains and
other
additives.
[0029] The star polymer may have a weight average molecular weight of
100,000
to 1,000,000, or 125,000 to 700,000, or 150,000 to 500,000, or 200,000 to
400,000.
The weight average molecular weight of an arm of the star polymer may be in
the
range of 8,000 to 150,000, or 10,000 to 100,000 or 15,000 to 75,000, or 25,000
to
70,000.
[0030] As used herein the shear stability index (SSI) of the star
polymer may be
determined by a 20 hour KRL test (Volkswagen Tapered Bearing Roller Test). The
test procedure is set out in both CEC-L-45-A-99 or equivalent test method DIN
51350-6-KRL/C .
[0031] The star polymer SSI may be in the range of 0 to 100, or 0 to 80,
or 0 to
60, or 0 to 50, 0 to 20, or 0 to 15, or 0 to 10, or 0 to 5. An example of a
suitable range
for the SSI includes 1 to 5, or 25 to 65.
[0032] The star polymer may be a homopolymer or a copolymer, that is, its
arms may be homopolymeric or copolymeric. In one embodiment the star
polymer may be a copolymer. The star polymer may be a star polymer having a
random, tapered, di-block, tri-block or multi-block architecture. Typically
the
star polymer has random or tapered architecture.
[0033] The star polymer may have arms that may have a block-arm
architecture, or hetero -arm architecture, or tapered-arm architecture.
Tapered-
7
arm architecture has a variable composition across the length of a star
polymer
arm. For example, the tapered arm may be composed of, at one end, a relatively
pure first monomer and, at the other end, a relatively pure second monomer.
The
middle of the arm is more of a gradient composition of the two monomers.
[0034] The star polymer derived from a block-arm typically contains one or
more star polymer arms derived from two or more monomers in block structure
within the same arm. A more detailed description of the block-arm is given in
Chapter 13 (pp. 333-368) of "Anionic Polymerization, Principles and Practical
Applications" by Henry Hsieh and Roderic Quirk (Marcel Dekker, Inc, New
York, 1996) (hereinafter referred to as Hsieh et al.).
[0035] The star polymer typically has architecture such that the arms
may be
chemically bonded to a core portion. The core portion may be a polyvalent
(meth) acrylic monomer, oligomer, polymer, or copolymer thereof, or a
polyvalent divinyl non-acrylic monomer, oligomer polymer, or copolymer
thereof In one embodiment the polyvalent divinyl non -acrylic monomer may be
divinyl benzene. In one embodiment the polyvalent (meth)acrylic monomer may
be an acrylate or methacrylate ester of a polyol or a methacrylamide of a
polyamine, such as an amide of a polyamine, for instance a methacrylamide or
an
acrylamide. In different embodiments the polyvalent (meth)acrylic monomer
may be (i) a condensation reaction product of an acrylic or methacrylic acid
with
a polyol or (ii) a condensation reaction product of an acrylic or methacrylic
acid
with a polyamine.
[0036] The polyol which may be condensed with the acrylic or
methacrylic
acid in one embodiment contains 2 to 20 carbon atoms, in another embodiment 3
to 15 carbon atoms and in another embodiment 4 to 12 carbon atoms; and the
number of hydroxyl groups present in one embodiment may be 2 to 10, in
another embodiment 2 to 4 and in another embodiment 2. Examples of polyols
include ethylene glycol, poly (ethylene glycols), alkane diols such as 1,6-
hexane
diol or triols such as trimethylolpropane, oligomerised trimethylolpropanes
such
as Bottom materials sold by Perstorp Polyols. Examples of polyamines include
polyalkylenepolyamines such as ethylenediamine, diethylenetriamine,
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tri ethyl enetetramine, tetraethyl en epentamine, pentaethyl en eh ex amin e,
and
mixtures thereof.
[0037] Examples of the polyvalent unsaturated (meth)acrylic monomer
include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene
glycol diacrylate, diethylene glycol dimethacrylate, glycerol diacrylate,
glycerol
triacrylate, mannitol hexaacrylate, 4-cyclohexanediol diacrylate, 1,4-
benzenediol
dimethacrylate, pentaerythritol tetraacrylate, 1,3-propanediol diacrylate, 1,5-
pentanediol dimethacrylate, bis-acrylates and methacrylates of polyethylene
glycols of molecular weight 200-4000, polycaprolactonediol diacrylate,
pentaerythritol triacrylate, 1,1,1 -trimethylolpropane triacrylate,
pentaerythritol
diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate,
triethylene
glycol diacrylate, triethylene glycol dimethacrylate, 1,1,1-trimethylolpropane
trimethacrylate, hexamethylenediol diacrylate or hexamethylenediol
dimethacrylate or an alkylene bis-(meth)acrylamide.
[0038] The star polymer with branched, comb-like, radial or star
architecture
may have 2 or more arms, or 5 or more arms, or 7 or more arms, or 10 or more
arms, for instance 12 to 100, or 14 to 50, or 16 to 40 arms. The star polymer
with
branched, comb-like, radial or star architecture may have 120 arms or less, or
80
arms or less, or 60 arms or less.
[0039] The star polymer may be obtained/obtainable from a controlled
radical
polymerisation technique. Examples of a controlled radical polymerisation
technique include RAFT, ATRP or nitroxide mediated processes. The star
polymer may also be obtained/obtainable from anionic polymerisation processes.
In one embodiment the star polymer may be obtained/obtainable from RAFT,
ATRP or anionic polymerisation process. In one embodiment the star polymer
may be obtained/obtainable from RAFT or ATRP polymerisation process. In one
embodiment the star polymer may be obtained/obtainable from a RAFT
polymerisation process.
[0040] Methods of preparing polymers using ATRP, RAFT or nitroxide-
mediated techniques are disclosed in the example section of International
Publication WO 2006/047398, see examples 1 to 47.
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[0041] More detailed descriptions of polymerisation mechanisms and
related
chemistry is discussed for nitroxide-mediated polymerisation (Chapter 10,
pages
463 to 522), ATRP (Chapter 11, pages 523 to 628) and RAFT (Chapter 12, pages
629 to 690) in the Handbook of Radical Polymerization, edited by Krzysztof
Matyjaszewski and Thomas P. Davis, 2002, published by John Wiley and Sons
Inc (hereinafter referred to as "Matyjaszewski et al.").
[0042] The discussion of the star polymer mechanism of ATRP
polymerisation is shown on page 524 in reaction scheme 11.1, page 566 reaction
scheme 11.4, reaction scheme 11,7 on page 571, reaction scheme 11.8 on page
572 and reaction scheme 11.9 on page 575 of Matyjaszewski et al. In ATRP
polymerisation, groups that may be transferred by a radical mechanism include
halogens (from a halogen-containing compound) or various ligands. A more
detailed review of groups that may be transferred is described in US
6,391,996,
or paragraphs 61 to 65 of International Publication WO 2006/047398.
[0043] In RAFT polymerisation, chain transfer agents are important. A more
detailed review of suitable chain transfer agents is found in paragraphs
[0066] to
[0071] of International Publication WO 2006/047398. In one embodiment a
suitable RAFT chain transfer agent includes 2-dodecylsulphanylthiocarbonyl-
sulphany1-2-methyl-propionic acid butyl ester, cumyl dithiobenzoate or
mixtures
thereof. A discussion of the star polymer mechanism of RAFT polymerisation is
shown on page 664 to 665 in section 12.4.4 of Matyjaszewski et al.
[0044] When the star polymer is prepared from anionic polymerisation
techniques, initiators include, for example, hydrocarbyl lithium initiators
such as
alkyl lithium compounds (e.g., methyl lithium, n-butyl lithium, sec-butyl
lithium), cycloalkyl lithium compounds (e.g., cyclohexyl lithium and aryl
lithium
compounds (e.g., phenyl lithium, 1-methylstyryl lithium, p-tolyl lithium,
naphyl
lithium and 1,1-dipheny1-3-methylpentyl lithium. Also, useful initiators
include
naphthalene sodium, 1,4 -disodio-1,1,4,4-tetraphenylbutane, diphenylmethyl
potassium or diphenylmethyl sodium.
[0045] A more detailed description of process to prepare the star polymer
derived from anionic processes is discussed in International Patent
Application
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WO 96/23012, page 3, line 11 to page 5, line 8. Page 7, line 25 to page 10,
line
15 of WO 96/23012 further describes methods of preparing polymers by anionic
polymerisation techniques. A detailed description of anionic polymerisation
process is given in Textbook of Star Polymer Science, edited by Fred W.
Billmeyer Jr., Third Edition, 1984, Chapter 4, pages 88-90.
[0046] The star
polymer may comprise at least one of (a) a star polymer
derived from monomers comprising: (i) a vinyl aromatic monomer; and (ii) a
carboxylic monomer (typically maleic anhydride, maleic acid, (meth)acrylic
acid,
itaconic anhydride or itaconic acid) or derivatives thereof; (b) a
poly(meth)acrylate; (c) a functionalised polyolefin; (d) an ethylene vinyl
acetate
copolymer; (e) a fumarate copolymer; (f) a copolymer derived from (i) an a¨
olefin and (ii) a carboxylic monomer (typically maleic anhydride, maleic acid,
(meth)acrylic acid, itaconic anhydride or itaconic acid) or derivatives
thereof; or
(g) mixtures thereof. In one embodiment the star polymer with pendant groups
comprises a polymethacrylate or mixtures thereof.
[0047] In one
embodiment the star polymer may be a poly(meth)acrylate
(typically a polymethacrylate). The star polymer may be derived from a
monomer composition comprising:
(a) 50 wt % to 100 wt % (or 65 wt % to 95 wt %) of an alkyl
(meth)acrylate, wherein the alkyl group of the (meth)acrylate has 10 to 30, or
10
to 20, or 12 to 18, or 12 to 15 carbon atoms, or mixtures thereof;
(b) 0 wt % to 40 wt % (or 5 wt % to 30 wt (Y0) of an alkyl (meth)acrylate,
wherein the alkyl group of the (meth)acrylate has 1 to 9, or 1 to 4 carbon
atoms
(for example methyl, butyl, or 2-ethylhexyl) , or mixtures thereof; and
(c) 0 wt % to 10 wt % (or 0 wt % to 5 wt %, or 0.1 to 2 wt %) of a
nitrogen-containing monomer.
[0048] In one
embodiment the star polymer may be a poly(meth)acrylate
(typically a polymethacrylate), the star polymer may be derived from a monomer
composition comprising:
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(a) 65 wt % to 95 wt (or 65
wt % to 94.9 wt %) of an alkyl
(meth)acrylate, wherein the alkyl group of the (meth)acrylate has 10 to 30, or
10
to 20, or 12 to 18, or 12 to 15 carbon atoms, or mixtures thereof;
(b) 5 wt % to 30 wt % of an alkyl (meth)acrylate, wherein the alkyl group
of the (meth)acrylate has 1 to 9, or 1 to 4 carbon atoms (for example methyl,
butyl, or 2-ethylhexyl) , or mixtures thereof; and
(c) 0 wt % to 5 wt % (or 0.1 to 2 wt %) of a nitrogen-containing
monomer.
[0049] The
alkyl (meth)acrylate includes, for example, compounds derived
from saturated alcohols, such as methyl (meth)acrylate, butyl (meth)acrylate,
2-methylpentyl (meth)acrylate, 2-propylheptyl (meth)acrylate, 2-butyloctyl
(meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl
(meth)-
acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, 2-tert-butylheptyl
(meth)acrylate, 3-isopropylheptyl (meth)acrylate, decyl (meth)acrylate,
undecyl
(meth)acrylate, 5-methylundecyl (meth)acrylate, dodecyl (meth)acrylate,
2-methyldodecyl (meth)acrylate, tridecyl (meth)acrylate, 5-methyltridecyl
(meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate,
hexadecyl
(meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate,
octadccyl (meth)acrylatc, nonadecyl (meth)acrylate, cicosyl (meth)acrylate,
cetyleicosyl (meth)acrylate, stearyleicosyl (meth)acrylate, docosyl
(meth)acrylate
and/or eicosyltetratriacontyl (meth)acrylate; (meth)acrylates derived from
unsaturated alcohols, such as oleyl (meth)acrylate; and cycloalkyl
(meth)acrylates,
such as 3-vinyl-2-butylcyclohexyl (meth)acrylate or bornyl (meth)acrylate.
[0050] The
alkyl (meth)acrylates with long-chain alcohol-derived groups may
be obtained, for example, by reaction of a (meth)acrylic acid (by direct
esterification) or methyl methacrylate (by transesterification) with long-
chain
fatty alcohols, in which reaction a mixture of esters such as (meth)acrylate
with
alkyl groups of various chain lengths is generally obtained. These fatty
alcohols
include Oxo Alcohol 7911, Oxo Alcohol 7900 and Oxo Alcohol 1100 of
Monsanto; Alphano10 79 of ICI; Nafol0 1620, Alfol0 610 and Alfol0 810 of
Condea (now Sasol); Epal0 610 and Epal0 810 of Ethyl Corporation; Linevol0
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79, Linevol 911 and Dobanol 25 L of Shell AG; Lial 125 of Condea
Augusta, Milan; Dehydad and Lorol of Henkel KGaA (now Cognis) as well
as Linopol 7-11 and Acropol 91 of Ugine Kuhlmann.
[0051] In one
embodiment the star polymer may be further functionalised in
the core or the polymeric arms with a nitrogen-containing monomer. The
nitrogen-containing monomer may be referred to as a dispersant monomer. The
nitrogen-containing monomer may include a vinyl-substituted nitrogen
heterocyclic monomer, a dialkylaminoalkyl (meth)acrylate monomer, a
dialkylaminoalkyl (meth)acrylamide monomer, a tertiary-(meth)acrylamide
monomer or mixtures thereof.
[0052] In one
embodiment the core or polymeric arms further comprise a
(meth)acrylamide or a nitrogen containing (meth)acrylate monomer. Examples
of a suitable nitrogen-containing vinyl monomer
include
N,N-dimethylacrylamide, N-vinyl carbonamides such as N-vinyl-formamide,
vinyl pyridine, N-vinylacetoamide, N-vinyl-n-propionamides, N-vinyl
hydroxyacetoamide, N-vinyl imidazole, N-vinyl pyrrolidinone, N-vinyl
caprolactam, dimethylamino ethyl acrylate (DMAEA), dimethylaminoethyl-
methacrylate (DMAEMA), dimethylaminobutylacrylamide, dimethylamino-
propylmethacrylate (DMAPMA), dimethylamine-propyl-acrylamide, dimethyl-
aminop ropylmetha cryl amide, dim ethyl amino ethyl- a crylami de, or mixtures
thereof.
[0053] A
dispersant monomer may also be oxygen-containing compound.
The oxygen-containing compound may include hydroxyalkyl (meth)acrylates
such as 3-hydroxypropyl (meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate, 2-
hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,5-dimethy1-1,6-
hexanediol (meth)acrylate, 1,10-decanediol (meth)acrylate, carbonyl-containing
(meth)acrylates such as 2 - carboxye thyl (meth)acrylate, carboxymethyl
(meth)acrylate, oxazolidinylethyl (meth)acrylate, N -
(methacryloyl-
o xy)fo rmami de, a c etonyl (m eth)a cryl at e, N -methacryloylmorpholine, N-
methacryloy1-2-pyrrolidinone, N-(2-methacryloyloxyethyl)-2-pyrrolidinone, N-
(3 -methacryloyloxypropy1)-2-pyrrolidinone, N-(2-methacryloyloxyp entadecy1)-
13
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2 -pyrrol i din on e, N-(3 -m ethacryl oyloxyh eptadecy1)-2-pyrroli din on
e; glycol
di(meth)acrylates such as 1,4 -butanediol (meth)acrylate, 2 -butoxyethyl
(meth)ac ryl ate, 2 -etho xyetho xymethyl (meth)acrylate, 2 -
etho xyethyl
(meth)acrylate, or mixtures thereof.
[0054] Other examples of suitable non-carbonyl oxygen containing
compounds capable of being incorporated into the copolymer include
(meth)acrylates of ether alcohols, such as tetrahydrofurfuryl (meth)acrylate,
vinyloxyethoxyethyl (meth)acrylate, methoxyethoxyethyl (meth)acrylate, 1 -
butoxypropyl (meth)acrylate, 1-methyl-(2-vinyloxy)ethyl (meth)acrylate, cyclo -
hexyloxymethyl (meth)acrylate, methoxymethoxyethyl (meth)
acryl ate,
b enzyloxymethyl (meth)acrylate, furfuryl (meth)acrylate, 2 -butoxyethyl
(meth)ac ryl ate , 2 -etho xyetho xymethyl (meth)acrylate, 2 -
etho xyethyl
(meth)acrylate, allyloxymethyl (meth)acrylate, 1-ethoxybutyl (meth)acrylate,
methoxymethyl (meth)acrylate, 1-ethoxyethyl (meth)acrylate, ethoxymethyl
(meth)acrylate and ethoxylated (meth)acrylates which typically have 1 to 20,
or 2
to 8, ethoxy groups, or mixtures thereof.
Substantially Linear Polymer
[0055] The
composition of the invention includes a substantially linear
polymer with a weight average molecular weight of 45,000 or less, or 35,000 or
less,
or 25,000 or less, or 8000 to 25,000, or 12,000 to 20,000.
[0056] The
substantially linear polymer may be a copolymer comprising units
derived from monomers (i) an a¨olefin and (ii) an ethylenically unsaturated
carboxylic acid or derivatives thereof esterified with an alcohol. In one
embodiment, the substantially linear polymer may be a copolymer comprising
units derived from monomers (i) one or more alpha olefins and (ii) one or more
alkyl (meth)acrylate esters. The ethylenically unsaturated carboxylic acid may
be
esterified with alcohol before or after polymerisation with the a¨olefin. In
one
embodiment the ethylenically unsaturated carboxylic acid may be esterified
with
alcohol before polymerisation with the a¨olefin. In one embodiment the
ethylenically unsaturated carboxylic acid may be esterified with alcohol after
polymerisation with the a¨olefin.
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[0057] A commercially available copolymer prepared by esterification
before
polymerisation is available from Akzo Nobel sold under the tradename
Ketjenlubet3700. The alcohol may have 1 to 40, or 1 to 30, or 4 to 20, or 6 to
16 carbon atoms. Examples of a suitable alcohol include 2-ethylhexanol, 2-
butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, butanol,
pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol,
tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol,
octadecanol,
eicosanol, or mixtures thereof A copolymer of this type is described in more
detail in US Patents 4,526,950, or 6,419,714, or 6,573,224, or 6,174,843.
[0058] The ethylenically unsaturated carboxylic acid may be esterified with
alcohol after polymerisation with the a¨olefin. A copolymer of this type may
be
a substantially linear polymer that may in one embodiment be (a) a copolymer
comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically
unsaturated carboxylic acid or derivatives thereof esterified with a primary
alcohol branched at the 13- or higher position, wherein the copolymer
typically
has a reduced specific viscosity of up to 0.2, (b) a poly(meth)acrylate, or
mixtures thereof.
[0059] The substantially linear polymer may be present in the
compositions
described herein at 0.1 wt % to 50 wt %, or 2 wt % to 40 wt %, or 5 wt % to 30
wt %, or 8 wt % to 20 wt % of the lubricating composition. In certain
embodiments the lubricating composition contains 0.3 to 15 wt `)/0 of star
polymer
and 1 to 35 wt % of substantially linear polymer. In other embodiments, the
lubricating composition contains 0.45 to 5 wt % of star polymer and 2 to 25 wt
%
of substantially linear polymer.
Linear Poly(meth)acrylate
[0060] In one embodiment the substantially linear polymer includes a
poly(meth)acrylate, or mixtures thereof.
[0061] In one embodiment the substantially linear polymer includes a
poly(meth)acrylate (typically a polymethacrylate) with units derived from a
mixture of alkyl (meth)acrylate ester monomers containing, (a) 8 to 24, or 12
to
18, or to 15 carbon atoms in the alcohol-derived portion of the ester group
and (b)
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6 to 11, or 8 to 11, or 8 carbon atoms in the alcohol-derived portion of the
ester
group, and which have 2-(C1_4 alkyl)-substituents, and optionally, at least
one
monomer selected from the group consisting of (meth)acrylic acid esters
containing 1 to 7 carbon atoms in the alcohol-derived portion of the ester
group
.. and which are different from (meth)acrylic acid esters (a) and (b), vinyl
aromatic
compounds (or vinyl aromatic monomers); and nitrogen-containing vinyl
monomers such as those disclosed above; provided that no more than 60% by
weight, or no more than 50% by weight, or no more than 35% by weight of the
esters contain not more than 10 carbon atoms in the alcohol-derived portion of
the
ester group. The linear polymer of this type is described in more detail in US
6,124,249, or EP 0 937 769 Al paragraphs [00191 and [00311 to [00671. (The
"alcohol-derived portion" refers to the "-OR" portion of an ester, when
written as
R'C(=0)-OR, whether or not it is actually prepared by reaction with an
alcohol.)
Optionally, the linear polymer may further contain a third monomer. The third
.. monomer may be styrene, or mixtures thereof. The third monomer may be
present
in an amount 0% to 25% of the polymer composition, or from 1% to 15% of the
composition, 2% to 10% of the composition, or even from 1% to 3% of the
composition.
[0062] Typically, the mole ratio of esters (a) to esters (b) in the
copolymer
ranges from 95:5 to 35:65, or 90:10 to 60:40, or 80:20 to 50:50.
[0063] The esters are usually aliphatic esters, typically alkyl esters.
In one
embodiment the ester of (a) may be a C p 15 alkyl methacrylate and the ester
of
(b) may be 2-ethylhexyl methacrylate.
[0064] In one embodiment, the ester groups in ester (a) contain branched
alkyl groups. The ester groups may contain 2 to 65%, or 5 to 60% of the ester
groups having branched alkyl groups.
[0065] The Ci_4 alkyl substituents may be methyl, ethyl, and any isomers
of
propyl and butyl.
[0066] The weight average molecular weight of the poly(meth)acrylate may
be
45,000 or less, or 35,000 or less, or 25,000 or less, or 8000 to 25,000, or
12,000 to
20,000.
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Copolymer of (i) a¨Olefin and (ii) an Ethylenically Unsaturated Carboxylic
Acid
or Derivatives Thereof
[0067] In one embodiment the substantially linear polymer includes a
copolymer comprising units derived from monomers (i) an a¨olefin and (ii) an
ethylenically unsaturated carboxylic acid or derivatives thereof esterified
with a
primary alcohol branched at the 13- or higher position, wherein the copolymer
typically has a reduced specific viscosity of up to 0.2, or up to 0.15, or up
to
0.10, or up to 0.08. In one embodiment the reduced specific viscosity may be
up
to 0.08 (or 0.02 to 0.08 (or 0.02 to 0.07, 0.03 to 0.07 or 0.04 to 0.06).
[0068] A measurement correlating with molecular weight of the copolymer
(or interpolymer such as an alternating copolymer) may be expressed in terms
of
the "reduced specific viscosity" of the copolymer which is a recognised means
of
expressing the molecular size of a polymeric substance. As used herein, the
reduced specific viscosity (abbreviated as RSV) is the value typically
obtained in
accordance with the formula RSV = (Relative Viscosity ¨ 1)/Concentration,
wherein the relative viscosity is determined by measuring, by means of a
dilution
viscometer, the viscosity of a solution of 1.6 g of the polymer in 100 cm3 of
acetone and the viscosity of acetone at 30 C. For purpose of computation by
the
above formula, the concentration is adjusted to 1.6 g of the copolymer per 100
cm3 of acetone. A more detailed discussion of the reduced specific viscosity,
also known as the specific viscosity, as well as its relationship to the
average
molecular weight of a copolymer, appears in Paul J. Flory, Principles of
Polymer
Chemistry, (1953 Edition) pages 308 et seq.
[0069] In one embodiment the copolymer may be derived from monomers (i)
an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid or
derivatives
thereof,
wherein 0.1 to 99.89 percent of the carboxylic acid units are esterified
with a primary alcohol branched at the 13- or higher position,
wherein 0.1 to 99.89 percent of the carboxylic acid units are esterified
with a linear alcohol or an alpha-branched alcohol (e.g, a secondary alcohol),
17
wherein 0.01 to 10 % of the carboxylic acid units has at least one of an
amino-, amido- and/or imido- group, and
wherein the copolymer has a reduced specific viscosity (prior to
esterification) of up to 0.08.
[0070] In one
embodiment the copolymer may be derived from monomers (i)
an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid or
derivatives
thereof,
wherein 0.1 to 99.89 percent of the carboxylic acid units are esterified
with a primary alcohol branched at the 13- or higher position,
wherein 0.1 to 99.9 percent of the carboxylic acid units are esterified with
a linear alcohol or an alpha-branched alcohol,
wherein 0 to 10 % of the carboxylic acid units has at least one of an
amino-, amido- and/or imido- group, and
wherein the copolymer has a reduced specific viscosity of up to 0.08.
[0071] A linear alcohol
may include methanol, ethanol, propanol, butanol,
pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol,
tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol,
octadecanol,
nonadecanol, eicosanol, or mixtures thereof. In one embodiment the linear
alcohol contains 6 to 30, or 8 to 20, or 8 to 15 carbon atoms (typically 8 to
15
carbon atoms).
[0072] The
linear alcohol may include commercially available materials such
as Oxo Alcohol 7911, Oxo Alcohol 7900 and Oxo Alcohol 1100 of
Monsanto; Alphanol0 79 of ICI; Nafol 1620, Alfol 610 and Alfol0 810 of
Condea (now Sasol); Epal0 610 and Epal0 810 of Ethyl Corporation (now
Afton); Linevol0 79, Linevol0 911 and Dobano10 25 L of Shell AG; Liale 125
of Condea Augusta, Milan; Dehydad and Lorol of Henkel KGaA (now
Cognis) as well as Linopol 7-11 and Acropol 91 of Ugine Kuhlmann.
[0073] In one
embodiment the copolymer may be derived from monomers (i)
an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid or
derivatives
thereof,
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wherein 5 to 15 percent of the carboxylic acid units are esterified with a
primary alcohol branched at the 13- or higher position,
wherein 0.1 to 95 percent of the carboxylic acid units are esterified with a
linear alcohol or an alpha-branched alcohol,
wherein 0 to less than 2 % of the carboxylic acid units has at least one of
an amino-, amido- and/or imido- group, and
wherein the copolymer has a reduced specific viscosity of up to 0.08.
[0074] In one
embodiment the copolymer comprises units derived from
monomers (i) an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid
or
derivatives thereof esterified with a primary alcohol branched at the 13- or
higher
position. In certain embodiments the copolymer may be represented by the
formula below. Ester or other groups with the primary alcohol-derived moiety
branched at the 13- or higher position may be represented within the ( ),
shown in
the formula:
R"
H
BB
Y
Formula (I)
wherein
Formula (I) may comprise a copolymer backbone (BB), and one or
more pendant groups as shown, wherein BB may be derived from a
copolymer of (i) an a¨olefin and (ii) an ethylenically unsaturated
carboxylic acid or derivatives thereof (typically fumaric acid, maleic
anhydride, maleic acid, (meth)acrylic acid, itaconic anhydride or itaconic
acid);
X may be a functional group which either (i) contains a carbon and
at least one oxygen or nitrogen atom (such as an ester or amide, or imide
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linkage), or (ii) is an alkylene group with 1 to 5 carbon atoms (typically
-CH2-), connecting the copolymer backbone and a branched hydrocarbyl
group contained within ( )y, (typically X may be X may be a functional
group which either (i) contains a carbon and at least one oxygen or
nitrogen atom);
w may be the number of pendant groups attached to the copolymer
backbone, which may be in the range of 2 to 2000, or 2 to 500, or 5 to 250;
y may be 0, 1, 2 or 3, provided that in at least 1 mol % of the pendant
groups, y is not zero; and with the proviso that when y is 0, X is bonded to
a terminal group in a manner sufficient to satisfy the valence of X,
wherein the terminal group is selected from hydrogen, alkyl, aryl, a metal
(typically introduced during neutralisation of ester reactions. Suitable
metals include calcium, magnesium, barium, zinc, sodium, potassium or
lithium) or ammonium cation, and mixtures thereof;
p may be an integer in the range of 1 to 15 (or 1 to 8, or 1 to 4);
and
R' and R" may independently be linear or branched hydrocarbyl
groups, and the combined total number of carbon atoms present in R' and
R" may be at least 12 (or at least 16, or at least 18 or at least 20).
100751 In different embodiments the copolymer with pendant groups may
contain 0.10 % to 100 %, or 0.5 % to 20 %, or 0.75 % to 10 %, branched
hydrocarbyl groups represented by a group within ( )y of the formula above,
expressed as a percentage of the total number of pendant groups. (The pendant
groups of formula (1) may also be used to define the ester groups as defined
above by the phrase "esterified with a primary alcohol branched at the p- or
higher position").
[0076] In
different embodiments the functional groups defined by X on the
formula above, may comprise at least one of -0O2-, -C(0)N= or
wherein v is an integer in the range of 1 to 20, or 1 to 10, or 1 to 2.
[0077] In one embodiment X may be derived from an ethylenically
unsaturated carboxylic acid or derivatives thereof. Examples of a suitable
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carboxylic acid or derivatives thereof typically include maleic anhydride,
maleic
acid, (meth)acrylic acid, itaconic anhydride or itaconic acid. In one
embodiment
the ethylenically unsaturated carboxylic acid or derivatives thereof may be at
least one of maleic anhydride or maleic acid.
[0078] In one embodiment X is other than an alkylene group, connecting the
copolymer backbone and the branched hydrocarbyl groups.
[0079] In different embodiments the pendant groups may be esterified,
amidated or imidated functional groups.
[0080] In one embodiment the pendant groups may be derived from
esterified
and/or amidated functional groups.
[0081] In one embodiment the copolymer includes esterified pendant
groups.
The pendant groups may be derived from Guerbet alcohols. The Guerbet
alcohols may contain 10 to 60, or 12 to 60, or 16 to 40 carbon atoms. In one
embodiment the primary alcohol branched at the 13- or higher position
described
herein may be a Guerbet alcohol. Methods to prepare Guerbet alcohols are
disclosed in US Patent 4,767,815 (see column 5, line 39 to column 6, line 32).
[0082] Examples of suitable groups for R' and R" on the formula defined
above include the following:
1) alkyl groups containing C15-16 polymcthylene groups, such as 2-C1_15
alkyl-hexadecyl groups (e.g. 2-0ctylhexadecyl) and 2-alkyl¨octadecyl groups
(e.g. 2-ethyloctadecyl, 2-tetradecyl-octadecyl and 2-hexadecyloctadecyl);
2) alkyl groups containing Ci3 14 polymethylene groups, such as 1-C1_15
alkyl-tetradecyl groups (e.g. 2-hexyltetradecyl, 2-decyltetradecyl and
2-undecyltridecyl) and 2-C115 alkyl-hexadecyl groups (e.g. 2-ethyl-hexadecyl
and 2-dodecylhexadecyl);
3) alkyl groups containing C10-12polymethylene groups, such as 2-C1_15
alkyl-dodecyl groups (e.g. 2-octyldodecyl) and 2-C1_15 alkyl-dodecyl groups
(2-hexyldodecyl and 2-octyldodecyl), 2-C1_15 alkyl-tetradecyl groups (e.g.
2-hexyltetradecyl and 2-decyltetradecyl);
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4) alkyl groups containing C6_9polymethylene groups, such as 2-C1_15
alkyl-decyl groups (e.g. 2-octyldecyl) and 2,4-di-C1_15 alkyl-decyl groups
(e.g. 2-
ethy1-4-butyl-decyl group);
5) alkyl groups containing C1_5 polymethylene groups, such as 2-(3-
methylhexyl)-7-methyl-decyl and 2-(1,4-dimethylbuty1)-5,7,7-trimethyl-octyl
groups; and
6) and mixtures of two or more branched alkyl groups, such as alkyl
residues of oxoalcohols corresponding to propylene oligomers (from hexamer to
undecamer), ethylene/propylene (molar ratio 16:1-1:11) oligomers, iso-butene
oligomers (from pentamer to octamer), C5_17 a-olefin oligomers (from dimer to
hexamer).
[0083] The
pendant groups may contain a total combined number of carbon
atoms on R. and R" in the range of 12 to 60, or 14 to 50, or 16 to 40, or 18
to 40,
or 20 to 36.
[0084] Each of R' and
R" may individually contain 5 to 25, or 8 to 32, or 10
to 18 methylene carbon atoms. In one embodiment the number of carbon atoms
on each R' and R" group may be 10 to 24.
[0085] Examples
of suitable primary alcohol branched at the 13- or higher
position include 2-ethylhexanol, 2-propyl heptanol, 2-butyloctanol, 2-
hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, or mixtures thereof.
[0086] The
ethylenically unsaturated carboxylic acid or derivatives thereof
may be an acid or anhydride or derivatives thereof that may be wholly
esterified,
partially esterified or mixtures thereof. When
partially esterified, other
functional groups include acids, salts or mixtures thereof. Suitable salts
include
alkali metals, alkaline earth metals or mixtures thereof. The salts include
lithium, sodium, potassium, magnesium, calcium or mixtures thereof. The
unsaturated carboxylic acid or derivatives thereof includes acrylic acid,
methyl
acrylate, methacrylic acid, maleic acid or anhydride, fumaric acid, itaconic
acid or
anhydride or mixtures thereof, or substituted equivalents thereof.
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[0087] Suitable
examples of the ethylenically unsaturated carboxylic acid or
derivatives thereof include itaconic anhydride, maleic anhydride, methyl
maleic
anhydride, ethyl maleic anhydride, dimethyl maleic anhydride or mixtures
thereof.
[0088] In one
embodiment the ethylenically unsaturated carboxylic acid or
derivatives thereof includes maleic anhydride or derivatives thereof.
[0089] Examples of an alpha-olefin include 1-decene, 1-undecene,
1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-hepta-
decene 1-octadecene, or mixtures thereof. An example of a useful alpha-olefin
is
1-dodecene. The alpha-olefin may be a branched alpha-olefin, or mixtures
thereof. If the a¨olefin is branched, the number of carbon atoms of the
a¨olefin
may range from 4 to 32, or 6 to 20, or 8 to 16.
[0090] In one
embodiment the copolymer of the invention further includes a
nitrogen containing group such as those disclosed above. The
nitrogen
containing group may be derived from a nitrogen containing compound capable
of being incorporated during copolymerization. In one embodiment the
copolymer of the invention further includes a nitrogen containing group that
may
be capable of reacting with the functionalised copolymer backbone, typically
for
capping the copolymer backbone. The capping may result in the copolymer
having ester, amide, imide or amine groups. The nitrogen group is described in
more detail in paragraphs [0069] to [0087] of PCT Patent Application Number
PCT/US09/052028, filed on July 29, 2009 by Price, Barton, Visger, entitled
"Novel Copolymers and Lubricating Compositions Thereof'.
[0091] In one
embodiment the copolymer comprises units derived from
monomers (i) an a¨olefin and (ii) an ethylenically unsaturated carboxylic acid
or
derivatives thereof may be further reacted with an amine to additionally
provide
oxidation control. Typically, the copolymer with oxidation control contains an
incorporated residue of an amine-containing compound such as morpholines,
pyrrolidinones, imidazolidinones, acetamides, 13-alanine alkyl esters, or
mixtures
thereof. Examples
of suitable nitrogen-containing compounds include 3-
morpholin-4-yl-propylamine, 3-morpholin-4-yl-ethylamine,13-alanine alkyl
esters
(typically alkyl esters have 1 to 30, or 6 to 20 carbon atoms), or mixtures
thereof.
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[0092] In one embodiment the compounds based on imidazolidinones, cyclic
carbamates or pyrrolidinones may be derived from a compound of general
structure:
0
X ________________________________ Hy
Hy"
Hy"
wherein
X = -OH or NH2;
Hy" may be hydrogen, or a hydrocarbyl group (typically alkyl, or C1_4-, or C2-
alkyl);
Hy may be a hydrocarbylene group (typically alkylene, or Ci_4-, or C2-
alkylene);
Q = >NH, >NR, >CH2, >CHR, >CR2, or -0- (typically >NH, or >NR) and
R may be Ci_4 alkyl.
[0093] In one embodiment the imidazolidinone includes 1-(2-amino-ethyl)-
imidazolidin-2-one (may also be called aminoethylethyleneurea), 1-(3-amino-
propy1)-imidazolidin-2-one, 1-(2-hydroxy-ethyl)-imidazolidin-2-one, 1-(3-amino-
propy1)-pyrrolidin-2-one, 1-(3-amino-ethyl)-pyrrolidin-2-one, or mixtures
thereof.
[0094] In one embodiment the copolymer may be reacted with an amine-
containing compound selected from morpholines, imidazolidinones, and mixtures
thereof.
Oils of Lubricating Viscosity
[0095] The lubricating composition comprises an oil of lubricating
viscosity.
Such oils include natural and synthetic oils, oil derived from hydrocracking,
hydrogenation, and hydrofinishing, unrefined, refined, re-refined oils or
mixtures
thereof. A more detailed description of unrefined, refined and re-refined oils
is
provided in International Publication W02008/147704, paragraphs [0054] to
[0056] (a similar disclosure is provided in US Patent Application 2010/197536,
see
[0072] to [0073]). A more detailed description of natural and synthetic
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lubricating oils is described in paragraphs [0058] to [0059] respectively of
W02008/147704 (a similar disclosure is provided in US Patent Application
2010/197536, see [0075] to [0076]). Synthetic oils may also be produced by
Fischer-Tropsch reactions and typically may be hydroisomerised Fischer-Tropsch
hydrocarbons or waxes. In one embodiment oils may be prepared by a Fischer-
Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.
[0096] Oils of lubricating viscosity may also be defined as specified in
April
2008 version of "Appendix E - API Base Oil Interchangeability Guidelines for
Passenger Car Motor Oils and Diesel Engine Oils", section 1.3 Sub-heading 1.3.
"Base Stock Categories". In one embodiment the oil of lubricating viscosity
may
be an API Group II or Group III oil. In one embodiment the oil of lubricating
viscosity may be an API Group III base oil (typically including
hydrocracked/hydroisomerized base oil).
[0097] The amount of the oil of lubricating viscosity present is
typically the
balance remaining after subtracting from 100 wt % the sum of the amount of the
compound of the invention and the other performance additives.
[0098] The lubricating composition may be in the form of a concentrate
and/or a fully formulated lubricant. If the lubricating composition of the
invention (comprising the additives disclosed herein) is in the form of a
concentrate which may be combined with additional oil to form, in whole or in
part, a finished lubricant), the ratio of the of these additives to the oil of
lubricating viscosity and/or to diluent oil include the ranges of 1:99 to 99:1
by
weight, or 80:20 to 10:90 by weight.
Other Performance Additives
[0099] Compositions derived from the copolymer and/or lubricating
compositions described herein optionally further includes other performance
additives. The other performance additives comprise at least one of metal
deactivators, detergents, dispersants, viscosity modifiers, friction
modifiers,
corrosion inhibitors, dispersant viscosity modifiers, antiwear agents, extreme
pressure agents, antiscuffing agents, antioxidants, foam inhibitors,
demulsifiers,
pour point depressants, seal swelling agents and mixtures thereof. Typically,
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fully-formulated lubricating oil will contain one or more of these performance
additives.
Dispersants
[0100]
Dispersants are known and include for example an N-substituted long
chain alkenyl succinimide, a Mannich base, or mixtures thereof. Examples of N-
substituted long chain alkenyl succinimides include polyisobutylene
succinimide,
wherein the polyisobutylene from which it is derived has a number average
molecular weight in the range 350 to 5000, or 500 to 3000, or 750 to 1150.
[0101] The
dispersants may also be post-treated by conventional methods by
a reaction with any of a variety of agents. Among these are boron compounds
(such as boric acid), urea, thiourea, dimercaptothiadiazoles, carbon
disulphide,
aldehydes, ketones, carboxylic acids such as terephthalic acid, hydrocarbon-
substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, and
phosphorus compounds. In one embodiment the post-treated dispersant is
borated. In one embodiment the post-treated dispersant is reacted with
dimercaptothiadiazoles.
Detergents
[0102]
Detergents are known and include neutral or overbased detergents, i.e.,
ones prepared by conventional processes known in the art. Suitable detergent
substrates include, phenates, sulphur containing phenates, sulphonates,
salixarates, salicylates, carboxylic acid, phosphorus acid, alkyl phenol,
sulphur
coupled alkyl phenol compounds, or saligenins. In one embodiment the
detergent includes a magnesium or calcium sulphonate, or mixtures thereof.
Antioxidant
[0103] Antioxidant compounds are known and include sulphurised olefins,
diphenylamines (such as dinonyl diphenylamine), hindered phenols, molybdenum
dithiocarbamates, and mixtures thereof. Antioxidant compounds may be used
alone or in combination.
[0104] The
hindered phenol antioxidant often contains a secondary butyl
.. and/or a tertiary butyl group as a sterically hindering group. The phenol
group is
often further substituted with a hydrocarbyl group and/or a bridging group
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linking to a second aromatic group. Examples of suitable hindered phenol
antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-
butylphenol, 4-
ethy1-2,6-di-tert-butylphenol, 4-propy1-2,6-di-tert-butylphenol or 4-buty1-2,6-
di-
tert-butylphenol, or 4-dodecy1-2,6-di-tert-butylphenol. In one embodiment the
hindered phenol antioxidant may be an ester and may include, e.g., IrganoxTM L-
135 from Ciba. Suitable examples of molybdenum dithiocarbamates which may
be used as an antioxidant include commercial materials sold under the trade
names such as Vanlube 822TM and MolyvanTM A from R. T. Vanderbilt Co., Ltd.,
and Adeka SakuraLubeTM S-100, S-165 and S-600 from Asahi Denka Kogyo K.
K and mixtures thereof.
Viscosity Modifiers
[0105] In addition to the polymers described herein as part of the
invention
the lubricating composition may optionally further contain other known
viscosity
modifiers. The viscosity modifiers may be hydrogenated styrene-butadiene
rubbers, ethylene-propylene copolym ers, hydrogenated styren e-isoprene
polymers, hydrogenated diene polymers, polyalkyl styrenes, polyolefins, esters
of maleic anhydride-styrene copolymers, or mixtures thereof
Antiwear Agent
[0106] The lubricating composition optionally further includes at least
one
antiwear agent. Examples of suitable antiwear agents include oil soluble amine
salts of phosphorus compounds, sulphurised olefins, metal dihydrocarbyldithio-
phosphates (such as zinc dialkyldithiophosphates), thiocarbamate -containing
compounds, such as thiocarbamate esters, thiocarbamate amides, thiocarbamic
ethers, alkylene -coupled thiocarbamates, and bis(S -alkyldithio carb amyl)
disulphides.
[0107] In one embodiment the oil soluble phosphorus amine salt antiwear
agent includes an amine salt of a phosphorus acid ester or mixtures thereof.
The
amine salt of a phosphorus acid ester includes phosphoric acid esters and
amine
salts thereof; dialkyldithiophosphoric acid esters and amine salts thereof;
amine
salts of phosphites; and amine salts of phosphorus-containing carboxylic
esters,
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ethers, and amides; and mixtures thereof. The amine salt of a phosphorus acid
ester may be used alone or in combination.
[0108] In one embodiment the oil soluble phosphorus amine salt includes
partial amine salt-partial metal salt compounds or mixtures thereof. In one
embodiment the phosphorus compound further includes a sulphur atom in the
molecule. In one embodiment the amine salt of the phosphorus compound may
be ashless, i.e., metal-free (prior to being mixed with other components).
[0109] The amines which may be suitable for use as the amine salt
include
primary amines, secondary amines, tertiary amines, and mixtures thereof. The
amines include those with at least one hydrocarbyl group, or, in certain
embodiments, two or three hydrocarbyl groups. The hydrocarbyl groups may
contain 2 to 30 carbon atoms, or in other embodiments 8 to 26, or 10 to 20, or
13
to 19 carbon atoms.
[0110] Primary amines include ethylamine, propylamine, butylamine,
2-ethylhexylamine, octylamine, and dodecyl amine, as well as such fatty amines
as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine,
n-hexadecylamine, n-octadecylamine and oleyamine. Other useful fatty amines
include commercially available fatty amines such as 'Armeen " amines
(products available from Akzo Chemicals, Chicago, Illinois), such as Armeen C,
Armeen 0, Armeen OL, Armeen T, Armeen HT, Armeen S and Armeen SD,
wherein the letter designation relates to the fatty group, such as coco,
oleyl,
tallow, or stearyl groups.
[0111] Examples of suitable secondary amines include dimethylamine,
diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine,
diheptylamine, methylethylamine, ethylbutylamine and ethylamylamine. The
secondary amines may be cyclic amines such as piperidine, piperazine and
morpholine.
[0112] The amine may also be a tertiary-aliphatic primary amine. The
aliphatic group in this case may be an alkyl group containing 2 to 30, or 6 to
26,
or 8 to 24 carbon atoms. Tertiary alkyl amines include monoamines such as tert-
butyl amine, tert-hexylamine, 1-methyl-1-amino -cyc lo hex ane, tert-o ctyl
amine,
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tert-decyl amine, tertdodecyl amine, tert-tetradecyl amine, tert-h ex adecyl
amine,
tert-octadecylamine, tert-tetracosanylamine, and tert-octacosanylamine.
[0113] In one embodiment the phosphorus acid amine salt includes an
amine
with C11 to C14 tertiary alkyl primary groups or mixtures thereof. In one
embodiment the phosphorus acid amine salt includes an amine with C14 to C18
tertiary alkyl primary amines or mixtures thereof. In one embodiment the
phosphorus acid amine salt includes an amine with C18 to C22 tertiary alkyl
primary amines or mixtures thereof.
[0114] Mixtures of amines may also be used in the invention. In one
embodiment a useful mixture of amines is "Primene 81R" and "Primene
JMT." Primene 81R and Primene JMT (both produced and sold by Rohm &
Haas) are mixtures of C11 to C14 tertiary alkyl primary amines and C18 to C22
tertiary alkyl primary amines respectively.
[0115] In one embodiment oil soluble amine salts of phosphorus compounds
.. include a sulphur-free amine salt of a phosphorus-containing compound may
be
obtained/obtainable by a process comprising: reacting an amine with either (i)
a
hydroxy-substituted di-ester of phosphoric acid, or (ii) a phosphorylated
hydroxy-
substituted di- or tri- ester of phosphoric acid. A more detailed description
of
compounds of this type is disclosed in International Application
PCITUS08/051126
.. (or equivalent to US Application 11/627405).
[0116] In one embodiment the hydrocarbyl amine salt of an
alkylphosphoric
acid ester is the reaction product of a C14 to C18 alkylated phosphoric acid
with
Primene 81RTM (produced and sold by Rohm & Haas) which is a mixture of Cll
to C14 tertiary alkyl primary amines.
[0117] Examples of hydrocarbyl amine salts of dialkyldithiophosphoric acid
esters include the reaction product(s) of isopropyl, methyl-amyl (4-methy1-2-
pentyl or mixtures thereof), 2-ethylhexyl, heptyl, octyl or nonyl
dithiophosphoric
acids with ethylene diamine, morpholine, or Primene 81RTM, and mixtures
thereof.
[0118] In one embodiment the dithiophosphoric acid may be reacted with
an
epoxide or a glycol. This reaction product is further reacted with a
phosphorus
acid, anhydride, or lower ester. The epoxide includes an aliphatic epoxide or
a
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styrene oxide. Examples of useful epoxides include ethylene oxide, propylene
oxide, butene oxide, octene oxide, dodecene oxide, and styrene oxide. In one
embodiment the epoxide may be propylene oxide. The glycols may be aliphatic
glycols having from 1 to 12, or from 2 to 6, or 2 to 3 carbon atoms. The
dithiophosphoric acids, glycols, epoxides, inorganic phosphorus reagents and
methods of reacting the same are described in U.S. Patent numbers 3,197,405
and
3,544,465. The resulting acids may then be salted with amines. An example of
suitable dithiophosphoric acid is prepared by adding phosphorus pentoxide
(about
64 grams) at 58 C over a period of 45 minutes to 514 grams of hydroxypropyl
0,0-di(4-methy1-2-pentyl)phosphorodithioate (prepared by reacting di(4-methy1-
2-penty1)-phosphorodithioic acid with 1.3 moles of propylene oxide at 25 C).
The mixture may be heated at 75 C for 2.5 hours, mixed with a diatomaceous
earth and filtered at 70 C. The filtrate contains 11.8% by weight phosphorus,
15.2% by weight sulphur, and an acid number of 87 (bromophenol blue).
[0119] The dithiocarbamate-containing compounds may be prepared by
reacting a dithiocarbamate acid or salt with an unsaturated compound. The
dithiocarbamate containing compounds may also be prepared by simultaneously
reacting an amine, carbon disulphide and an unsaturated compound. Generally,
the reaction occurs at a temperature from 25 C to 125 C.
[0120] Examples of suitable olefins that may be sulphurised to form an the
sulphurised olefin include propylene, butylene, 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 useful olefins.
Alternatively, the olefin may be a Diels-Alder adduct of a diene such as
1,3-butadiene and an unsaturated ester, such as, butylacrylate.
[0121] Another class of sulphurised olefin includes 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
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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/or ester are mixed with olefins.
[0122] In an alternative embodiment, the ashless antiwear agent may be a
monoester of a polyol and an aliphatic carboxylic acid, often an acid
containing
12 to 24 carbon atoms. Often the monoester of a polyol and an aliphatic
carboxylic acid is in the form of a mixture with a sunflower oil or the like,
which
may be present in the friction modifier mixture from 5 to 95, in several
embodiments from 10 to 90, or from 20 to 85, or 20 to 80 weight percent of
said
mixture. The aliphatic carboxylic acids (especially a monocarboxylic acid)
which form the esters are those acids typically containing 12 to 24, or from
14 to
carbon atoms. Examples of carboxylic acids include dodecanoic acid, stearic
acid, lauric acid, behenic acid, and oleic acid.
15 [0123] Polyols include diols, triols, and alcohols with higher
numbers of
alcoholic OH groups. Polyhydric alcohols include ethylene glycols, including
di-,
tri- and tetraethylene glycols; propylene glycols, including di-, tri- and
tetrapropylene glycols; glycerol; butane diol; hexane diol; sorbitol;
arabitol;
mannitol; sucrose; fructose; glucose; cyclohexane diol; crythritol; and penta-
20 erythritols, including di- and tripentaerythritol. Often the polyol is
diethylene
glycol, triethylene glycol, glycerol, sorbitol, pentaerythritol or dip
entaerythritol.
[0124] The commercially available monoester known as "glycerol
monooleate" is believed to include 60 + 5 percent by weight of the chemical
species glycerol monooleate, along with 35 + 5 percent glycerol dioleate, and
less than 5 percent trioleate and oleic acid. The amounts of the monoesters,
described above, are calculated based on the actual, corrected, amount of
polyol
monoester present in any such mixture.
Extreme Pressure Agents
[0125] Extreme Pressure (EP) agents that are soluble in the oil include
sulphur- and chlorosulphur-containing EP agents, chlorinated hydrocarbon EP
agents and phosphorus EP agents. Examples of such EP agents include
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chlorinated wax; sulphurised olefins (such as sulphurised isobutylene),
organic
sulphides and polysulphides such as dibenzyldisulphide, bis¨(chlorobenzyl)
disulphide, dibutyl tetrasulphide, 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; dip entylphenyl phosphite, tridecyl phosphite, distearyl phosphite
and
polypropylene substituted phenol phosphite; metal thiocarbamates such as zinc
dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl
and
dialkylphosphoric acids or derivatives including, for example, the amine salt
of a
reaction product of a dialkyldithiophosphoric acid with propylene oxide and
subsequently followed by a further reaction with P205; and mixtures thereof
(as
described in US 3,197,405).
[0126] Corrosion inhibitors that may be useful in the compositions of
the
invention include fatty amines, octyl octanamide, condensation products of
dodecenyl succinic acid or anhydride and a fatty acid such as oleic acid with
a
polyaminc.
[0127] Foam inhibitors that may be useful in the compositions of the
invention include copolymers of ethyl acrylate and 2-ethylhexylacrylate and
optionally vinyl acetate; demulsifiers including trialkyl phosphates,
polyethylene
glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-
propylene oxide) polymers.
[0128] Pour point depressants that may be useful in the compositions of the
invention include polyalphaolefins, esters of maleic anhydride-styrene
copolymers, poly(meth)acrylates, polyacrylates or polyacrylamides.
[0129] Friction modifiers that may be useful in the compositions of the
invention include fatty acid or fatty alkyl derivatives such as amines,
esters,
epoxides, fatty imidazolines, condensation products of carboxylic acids and
polyalkylene-polyamines and amine salts of alkylphosphoric acids. Other
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friction modifiers include fatty derivatives of hydroxyl carboxylic acids such
as
dialkyl tartrates, alkyl tartrimides, or citrate esters.
Industrial Application
[0130] The method and lubricating composition of the invention may be
suitable for refrigeration lubricants, greases, gear oils, axle oils, drive
shaft oils,
traction oils, manual transmission oils, automatic transmission oils, metal
working fluids, hydraulic oils, or internal combustion engine oils.
[0131] In one embodiment the method and lubricating composition of the
invention may be suitable for at least one of gear oils, axle oils, drive
shaft oils,
traction oils, manual transmission oils or automatic transmission oils. In one
embodiment the invention provides a method of lubricating a manual
transmission.
[0132] An automatic transmission includes continuously variable
transmissions (CVT), infinitely variable transmissions (IVT), toroidal
transmissions, continuously slipping torque converter clutches (CSTCC),
stepped
automatic transmissions or dual clutch transmissions (DCT).
[0133] The use (may also be referred to as a method) and copolymer
composition described herein is capable of providing a lubricant with at least
one
(or at least two, or all) of acceptable or improved shear stability,
acceptable or
improved viscosity index control, acceptable or improved oxidation control,
and
acceptable or improved low temperature viscosity. The copolymer may be
employed as an oil of lubricating viscosity in the presence or absence of
other
base oils.
[0134] When the copolymer with pendant groups further includes a
nitrogen
.. containing compound, the copolymer may further have acceptable/improved
dispersancy properties (cleanliness) and oxidation control.
[0135] The internal combustion engine may be a 2-stroke or 4-stroke
engine.
Suitable internal combustion engines include marine diesel engines, aviation
piston engines, low-load diesel engines, and automobile and truck engines.
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[0136] In
several embodiments a suitable lubricating composition includes the
copolymer present (on an actives basis) in ranges as shown in the following
table.
Table
Embodiments (wt % of lubricant composition)
A
Star Polymer 0.1-30 2-30 5-20 8-15
Substantially Linear Polymer 0.1-50 2-40 5-30 8-20
Other Performance Additives 0-15 0.01-15 0.5-10 0.5-10
Oil of Lubricating Viscosity 5-99.8 15-95.99 40-89.5 55-85.5
Embodiments (wt % of lubricant composition)
Star Polymer 0.1-20 0.2-15 0.5-10 1-8
Substantially Linear Polymer 0.1-50 2-40 5-30 8-20
Other Performance Additives 0-15 0.01-15 0.5-10 0.5-10
Oil of Lubricating Viscosity 5-99.7 15-97.79 40-94 55-90.5
Footnote: The star polymer and the substantially linear polymer arc those
described herein as part of the invention.
[0137] The
weight percent of the star polymer and the substantially linear
polymer may also be in the following ranges 5 wt % to 20 wt % of star polymer
and 5 wt % to 15 wt % of the substantially linear polymer of the lubricating
composition disclosed herein. The weight percent of the star polymer and the
substantially linear polymer may also be in the following ranges 8 wt % to 15
wt
% of star polymer and 5 wt % to 10 wt % of the substantially linear polymer of
the lubricating composition disclosed herein.
[0138] The
weight ratio of the star polymer to the substantially linear polymer
may also vary from 6:1 to 1:1, or 4:1 to 1.1, or 3:1 to greater than 2:1. A
ratio
closer to 2:1 may begin to become less shear stable than ratios greater than
2:1.
In other embodiments, the ratio may be 0.02:1 to 18:1, and in yet other
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embodiments, the ratios may be 0.04:1 to 9:1 or 0.1:1 to 4:1 or 0.2:1 to
2:1.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
[0139] Star Polymers 1 to 13 (SP1 to SP13): Polymers are the same as those
disclosed on page 32, paragraph [0100] of International Publication WO
2006/047393 (equivalent to US Publication 2009-0118150) respectively, except
monomer B (as is shown in Table 9 of WO 2006/047393) is methyl methacrylate.
[0140] Substantially linear polymers 1 to 8 (SLP1 to SLP8) with a weight
average
molecular weight of 45,000 or less are disclosed in International Application
PCT/US09/052028 (filed 29 July, 2009 by Barton et al., now W02010/014655)
respectively; see examples Cppl to Cpp8 in paragraphs [0140] and [0141].
[0141] Comparative Example 1 (CE1) is a manual transmission lubricant
based on an API Group III base oil further containing 0.45 wt % of one or more
corrosion inhibitors, 0.75 wt % of one or more antioxidants, 0.68 wt % of one
or
more antiwear agents, 0.62 wt % of one or more detergents, 1.5 wt % of one or
more dispersants, 1 wt % of one or more pour point depressant, 0.02 wt % of
one
or more antifoam agent and 20 wt % of the copolymer of SLP1.
[0142] Comparative Example 2 (CE2) is manual transmission lubricant
similar to CE1, except it contains 16 wt % of the polymer of SP11.
[0143] Invention lubricant 1 (INVL1) is a manual transmission lubricant
similar to CE1, except the copolymer of SLP1 is present at 11 wt % and the
polymer of SP13 is present at 10 wt %.
[0144] The manual transmission lubricants are evaluated using the
following
test procedures: ASTM D445 (Kinematic Viscosity (KV) at 40 C and 100 C,
ASTM D2983 (Brookfield Viscosity (BV) are determined at -40 C), D2270
(Viscosity Index (VI)), KRL tapered bearing shear stability test (KRL Test),
and
an Energy Loss test
[0145] The lubricating compositions are subjected to shear as determined
by
KRL tapered bearing shear stability test employing a 4-ball wear test
instrument
as is used in CEC DIN 51350 Part 6 test procedure. The instrument is run for
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hours with a 5000 N load, at 140 C and at 1450 rpm. The viscosity data
obtained from the test is described in ASTM method D445.
[0146] Energy loss data and maximum temperature of gearbox are measured
as is described below. A transverse 5-speed gearbox modified by locking the
gear differential in fourth gear. The gearbox input is driven by an electric
motor
and the output load applied by a dynamometer; the size of each should be
suitable for the test profile. The gear box is mounted in a temperature
controlled
environment, capable of maintaining a temperature of -7 C. The gearbox is pre-
soaked at -7 C for at least 60 minutes. The low power NEDC test cycle is used
throughout the test. The input speed for the NEDC cycle is calculated to match
the correct output/road speed using available tyre diameters and gear ratios.
In a
similar manner the applied load is calculated from the NEDC test cycle using
the
assumptions of a medium sector passenger car, tyre diameter, and gear ratios.
The output from the test is the sump temperature and energy absorbed at the
end
of each stage. These are measure via a thermocouple in the gearbox sump and
input/output torque transducers. The test is performed in triplicate. The
results
reported are the average based on the three runs. Typically better results are
obtained for samples with a lower temperature at the end of stage 5, and for
samples with lower energy loss values.
[0147] The results obtained for viscometrics evaluations are:
CE1 CE2 INVL1
D445 at 100 C 9.03 8.37 8.48
(mm2/s)
D445 at 40 C 46.2 28.4 33.0
(mm2/s)
D2983 at -40 43,400
12,020 14,640
C (mm2/s)
VI 181 196 251
Kinematic Viscosity at 100 C after 8.64 6.08 6.89
KRL Test KRL Shear (mm2/s)
Viscosity Loss After Shear Test (`)/0) 4.42 27.36 18.94
36
0 =
[0148] The results obtained for energy loss and maximum
temperature ( C) are:
CE1 CE2 INVL1
Stage 1 Loss (kJ) 86.3 58.1 54.8
Stage 2 Loss (kJ) 76.8 56.2 51.1
Stage 3 Loss (kJ) 69.8 53.3 48.3
Stage 4 Loss (kJ) 66.6 52.2 47.4
Stage 5 Loss (kJ) 283.7 242.5 221
Total Energy Loss (kJ) 44.9 38.2 34.4
Stage 1 Maximum Temperature ( C) -1.8 -3.9 -4.1
Stage 2 Maximum Temperature ( C) 1.2 -2 -2.3
Stage 3 Maximum Temperature ( C) 3.2 -0.6 -1.1
Stage 4 Maximum Temperature ( C) 4.5 0.4 -0.1
Stage 5 Maximum Temperature ( C) 15.2 9.6 8.7
[0149] The results indicate that the example of the
invention has an improved
shear stability, has lost less energy and has reduced operating temperature
5 compared to either of the comparative examples.
101501 It is known that some of the materials described
above may interact in
the final formulation, so that the components of the final formulation may be
different from those that are initially added. The products formed thereby,
including the products formed upon employing lubricant composition of the
10 present invention in its intended use, may not be susceptible of easy
description.
Nevertheless, all such modifications and reaction products are included within
the scope of the present invention; the present invention encompasses
lubricant
composition prepared by admixing the components described above.
15 [0151] Except in the Examples, or where otherwise explicitly
indicated, all
numerical quantities in this description specifying amounts of materials,
reaction
conditions, molecular weights, number of carbon atoms, and the like, are to be
understood as modified by the word "about." Unless otherwise indicated, each
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chemical or composition referred to herein should be interpreted as being a
commercial grade material which may contain the isomers, by-products,
derivatives, and other such materials which are normally understood to be
present in the commercial grade. However, the amount of each chemical
.. component is presented exclusive of any solvent or diluent oil, which may
be
customarily present in the commercial material, unless otherwise indicated. It
is
to be understood that the upper and lower amount, range, and ratio limits set
forth herein may be independently combined. Similarly, the ranges and amounts
for each element of the invention may be used together with ranges or amounts
for any of the other elements.
[0152] As used herein, the term "(meth) acrylic" and related terms
includes
both acrylic and methacrylic groups.
[0153] As used herein, the term "a primary alcohol branched at the 13-
or
higher position" relates to an alcohol with branching at the 2- position or a
higher
position (e.g., 3-, or 4-, or 5-, or 6-, or 7- position etc.)
[0154] As used herein the number of carbon atoms present in the ester
groups
of the polymers of the invention is counted to include only those carbon atoms
of
the alcohol-derived portion of the ester group. Specifically, the number of
carbon atoms excludes the carbonyl carbon of the ester.
[0155] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl
group" is used in its ordinary sense, which is well-known to those skilled in
the
art. Specifically, it refers to a group having a carbon atom directly attached
to
the remainder of the molecule and having predominantly hydrocarbon character.
Examples of hydrocarbyl groups include: hydrocarbon substituents, including
aliphatic, alicyclic, and aromatic substituents; substituted hydrocarbon
substituents, that is, substituents containing non-hydrocarbon groups which,
in
the context of this invention, do not alter the predominantly hydrocarbon
nature
of the substituent; and hetero substituents, that is, substituents which
similarly
have a predominantly hydrocarbon character but contain other than carbon in a
ring or chain. A more detailed definition of the term "hydrocarbyl
substituent"
or "hydrocarbyl group" is described in paragraphs [0118] to [0119] of
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International Publication W02008147704 (a similar description of hydrocarbyl
is
also described in paragraphs [0137] to [0141] of published application US 2010-
0197536.
[0156] While the invention has been explained in relation to its
preferred
embodiments, 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.
39
