U.S. patent application number 12/164893 was filed with the patent office on 2009-12-31 for functionalized olefin copolymer additive composition.
Invention is credited to Mark T. Devlin, Akhilesh Duggal, Naresh C. Mathur.
Application Number | 20090325831 12/164893 |
Document ID | / |
Family ID | 40908442 |
Filed Date | 2009-12-31 |
United States Patent
Application |
20090325831 |
Kind Code |
A1 |
Mathur; Naresh C. ; et
al. |
December 31, 2009 |
FUNCTIONALIZED OLEFIN COPOLYMER ADDITIVE COMPOSITION
Abstract
An additive concentrate comprising a viscosity index modifying
copolymer comprising the reaction product of an acylated
ethylene-olefin copolymer and a polyamine, and lubricating
compositions containing the same are provided. Methods of improving
boundary film resistance of a lubricating composition and modifying
the viscosity of a lubricating composition are also provided.
Inventors: |
Mathur; Naresh C.;
(Midlothian, VA) ; Duggal; Akhilesh; (Midlothian,
VA) ; Devlin; Mark T.; (Richmond, VA) |
Correspondence
Address: |
MH2 TECHNOLOGY LAW GROUP (Cust. No. w/NewMarket)
1951 KIDWELL DRIVE, SUITE 550
TYSONS CORNER
VA
22182
US
|
Family ID: |
40908442 |
Appl. No.: |
12/164893 |
Filed: |
June 30, 2008 |
Current U.S.
Class: |
508/259 ;
508/307; 508/545; 508/563 |
Current CPC
Class: |
C10M 2215/221 20130101;
C10N 2040/252 20200501; C10N 2040/255 20200501; C10N 2040/044
20200501; C10N 2030/02 20130101; C10M 2217/028 20130101; C10N
2040/045 20200501; C08F 255/00 20130101; C10N 2040/25 20130101;
C10M 2217/024 20130101; C10N 2040/253 20200501; C10N 2040/04
20130101; C10M 2205/022 20130101; C10M 2205/026 20130101; C10N
2020/04 20130101; C08L 51/06 20130101; C10M 2205/00 20130101; C10N
2020/02 20130101; C10M 2215/066 20130101; C10M 2205/02 20130101;
C10N 2040/08 20130101; C10N 2040/06 20130101; C10M 2217/06
20130101; C10M 2215/02 20130101; C10M 149/06 20130101; C10N 2070/02
20200501; C10N 2030/56 20200501; C10M 2215/04 20130101; C08L 51/06
20130101; C08L 2666/02 20130101; C08L 51/06 20130101; C08L 2666/14
20130101; C08L 51/06 20130101; C08L 2666/04 20130101; C10M 2205/00
20130101; C10M 2205/022 20130101; C10M 2205/02 20130101; C10M
2205/022 20130101; C10M 2205/022 20130101; C10M 2205/024 20130101;
C10M 2205/022 20130101; C10M 2205/08 20130101; C10M 2205/022
20130101; C10M 2205/026 20130101; C10M 2205/022 20130101; C10M
2205/028 20130101; C10M 2205/022 20130101; C10M 2205/024 20130101;
C10M 2209/086 20130101; C10N 2060/09 20200501; C10M 2205/022
20130101; C10M 2205/04 20130101; C10M 2205/026 20130101; C10M
2209/086 20130101; C10N 2060/14 20130101; C10M 2205/022 20130101;
C10M 2205/024 20130101; C10M 2209/086 20130101; C10N 2060/09
20200501; C10M 2205/026 20130101; C10M 2209/086 20130101; C10N
2060/14 20130101 |
Class at
Publication: |
508/259 ;
508/545; 508/563; 508/307 |
International
Class: |
C10M 133/40 20060101
C10M133/40; C10M 133/00 20060101 C10M133/00; C10M 133/12 20060101
C10M133/12; C10M 129/20 20060101 C10M129/20 |
Claims
1. An additive concentrate comprising: a carrier or diluent oil;
and a viscosity index modifying copolymer comprising the reaction
product of an acylated ethylene-olefin copolymer and a polyamine,
wherein the polyamine comprises at least two primary or secondary
amine functional groups.
2. The additive concentrate of claim 1, wherein the carrier or
diluent oil is present in an amount ranging from about 20 to about
90 weight percent, on an active ingredient basis, and the viscosity
index modifying copolymer is present in an amount ranging from
about 3 to about 45 weight percent of a viscosity index modifying
copolymer.
3. The additive concentrate of claim 1, wherein the acylated
ethylene-olefin copolymer comprises a copolymer of ethylene and one
or more C.sub.3-C.sub.28 alpha-olefins.
4. The additive concentrate of claim 1, wherein the acylated
ethylene-olefin copolymer has a number average molecular weight of
from about 20,000 to about 45,000.
5. The additive concentrate of claim 3, wherein said
C.sub.3-C.sub.28 alpha-olefin is selected from the group consisting
of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, styrene,
1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene,
4-methylbutene-1,5-methylpentene-1,6-methylheptene-1, and mixtures
thereof.
6. The additive concentrate of claim 1, wherein said polyamine is
selected from the group consisting of: (a) 4,4-diaminodiphenylamine
represented by formula (I): ##STR00003## wherein R.sup.1 and
R.sup.2 are each independently H or alkyl group comprising from
about 1 to about 24 carbon atoms; (b) polytetrahydrofuran
bis(aminopropyl) terminated; (c) hexamethylene diamine; (d)
bis(aminopropyl)piperazine; and (e) phenylenediamine represented by
formula (II): ##STR00004## wherein R.sub.1 and R.sub.2 are each
independently H or alkyl group comprising from about 1 to about 24
carbon atoms.
7. The additive concentrate of claim 1, further comprising at least
one additive selected from the group consisting of additional
viscosity index improvers, antioxidants, corrosion inhibitors,
detergents, dispersants, pour point depressants, antiwear agents,
antifoamants, demulsifiers, and friction modifiers.
8. A lubricating composition comprising: a major amount of an oil
of lubricating viscosity; and a minor amount of an additive
concentrate comprising a viscosity index modifying copolymer
comprising the reaction product of an acylated ethylene-olefin
copolymer and a polyamine, wherein the polyamine comprises at least
two primary or secondary amine functional groups.
9. The lubricating composition of claim 8, wherein the acylated
ethylene-olefin copolymer comprises a copolymer of ethylene and one
or more C.sub.3-C.sub.28 alpha-olefins.
10. The lubricating composition of claim 9, wherein said
C.sub.3-C.sub.28 alpha-olefin is selected from the group consisting
of propylene, 1-butene; 1-pentene, 1-hexene, 1-octene, styrene,
1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene,
4-methylbutene-1,5-methylpentene-1,6-methylheptene-1, and mixtures
thereof.
11. The lubricating composition of claim 8, wherein the acylated
ethylene-olefin copolymer has a number average molecular weight of
from about 20,000 to about 45,000
12. The lubricating composition of claim 8, wherein said polyamine
is selected from the group consisting of: (a)
4,4-diaminodiphenylamine represented by formula (I): ##STR00005##
wherein R.sup.1 and R.sup.2 are each independently H or alkyl group
comprising from about 1 to about 24 carbon atoms; (b)
polytetrahydrofuran bis(aminopropyl) terminated; (c) hexamethylene
diamine; (d) bis(aminopropyl)piperazine; and (e) phenylenediamine
represented by formula (II): ##STR00006## wherein R.sub.1 and
R.sub.2 are each independently H or alkyl group comprising from
about 1 to about 24 carbon atoms.
13. The lubricating composition of claim 8, wherein the viscosity
index modifying copolymer is present in an amount ranging from
about 0.1 wt. % to about 2.0 wt. %, relative to the total weight of
the lubricating composition.
14. The lubricating composition of claim 8, wherein the viscosity
index modifying copolymer is present in an amount ranging from
about 0.5 wt. % to about 1.0 wt. %, relative to the total weight of
the lubricating composition.
15. The lubricating composition of claim 8, further comprising at
least one additive selected from the group consisting essentially
of additional viscosity index improvers, antioxidants, corrosion
inhibitors, detergents, dispersants, pour point depressants,
antiwear agents, antifoamants, demulsifiers, and friction
modifiers.
16. A method of improving boundary film resistance of a lubricating
composition, said method comprising: providing a major amount of an
oil of lubricating viscosity; and mixing with said oil a minor
amount of an additive concentrate comprising a viscosity index
modifying copolymer comprising the reaction product of an acylated
ethylene-olefin copolymer and a polyamine, wherein the polyamine
comprises at least two primary or secondary amine functional
groups.
17. A method of modifying the viscosity of a lubricating
composition, said method comprising: providing a major amount of an
oil of lubricating viscosity; and mixing with said oil a minor
amount of an additive concentrate comprising a viscosity index
modifying copolymer comprising the reaction product of an acylated
ethylene-olefin copolymer and a polyamine, wherein the polyamine
comprises at least two primary or secondary amine functional
groups.
18. A method of lubricating an automotive engine, said method
comprising adding to and operating in the crankcase of said
automotive engine a lubricating composition comprising: a major
amount of an oil of lubricating viscosity; and a minor amount of an
additive concentrate comprising a viscosity index modifying
copolymer comprising the reaction product of an acylated
ethylene-olefin copolymer and a polyamine, wherein the polyamine
comprises at least two primary or secondary amine functional
groups.
Description
FIELD OF THE DISCLOSURE
[0001] This disclosure relates to a highly grafted,
multi-functionalized olefin copolymer lubricant additive useful as
an improved viscosity index modifier and lubricating compositions
comprising thereof. The present disclosure further relates to a
lubricant additive effective for imparting boundary film resistance
and viscosity modifying properties to a lubricating composition.
The present disclosure also provides a method of at least one of
improving boundary film resistance of a lubricating composition and
modifying the viscosity of a lubricating composition.
BACKGROUND OF THE DISCLOSURE
[0002] Polymer additives for improving properties of lubricating
compositions, such as viscosity index improving additives, are
known. Viscosity index improving additives reduce the influence of
temperature change on fluid viscosity. Of the viscosity index
improving lubricant additives, olefin copolymers are particularly
suitable for such applications. Ethylene-propylene copolymers and
ethylene-alpha olefin non-conjugated diene terpolymers, which have
been further derivatized to provide bifunctional properties in
lubricating compositions, illustrate this type of additive.
[0003] Lubricant additives produced from the reaction product of an
acylated olefin copolymer and certain polyamines are also known.
However, such additives were generally preferred to contain only
one primary amine, as it was previously thought that more than one
primary amine would cause coupling and/or gelling of the olefin
copolymers. An unexpected result of the present disclosure is that
certain polyamines containing two or more primary or secondary
amine functional groups can be reacted with an acylated
ethylene-olefin copolymer to produce a lubricant additive with
improved characteristics of the olefin copolymers.
SUMMARY OF THE DISCLOSURE
[0004] In accordance with the disclosure, there is provided a
viscosity index modifying copolymer comprising the reaction product
of an acylated ethylene-olefin copolymer and a polyamine, wherein
the polyamine comprises at least two primary or secondary amine
functional groups.
[0005] In an aspect, there is also provided an additive concentrate
comprising, on an active ingredient basis, from about 20 to about
90 weight percent of a carrier or diluent oil and from about 3 to
about 45 weight percent of a viscosity index modifying copolymer
comprising the reaction product of an acylated ethylene-olefin
copolymer and a polyamine, wherein the polyamine comprises at least
two primary or secondary amine functional groups.
[0006] Moreover, there is also provided a lubricating composition
comprising a major amount of an oil of lubricating viscosity and a
minor amount of a viscosity index modifying copolymer comprising
the reaction product of an acylated ethylene-olefin copolymer and a
polyamine, wherein the polyamine comprises at least two primary or
secondary amine functional groups.
[0007] Further, there is provided a method of improving boundary
film resistance of a lubricating composition comprising providing a
major amount of an oil of lubricating viscosity and mixing with
said oil a minor amount of a viscosity index modifying copolymer
comprising the reaction product of an acylated ethylene-olefin
copolymer and a polyamine, wherein the polyamine comprises at least
two primary or secondary amine functional groups
[0008] Another aspect of the disclosure is directed to a method of
modifying the viscosity of a lubricating composition comprising
combining a major amount of an oil of lubricating viscosity and a
minor amount of a viscosity index modifying copolymer comprising
the reaction product of an acylated ethylene-olefin copolymer and a
polyamine, wherein the polyamine comprises at least two primary or
secondary amine functional groups.
[0009] Additionally, there is provided a method of lubricating an
automotive engine comprising adding to and operating in the
crankcase of the engine a lubricating composition comprising a
major amount of an oil of lubricating viscosity and a minor amount
of a viscosity index modifying copolymer comprising the reaction
product of an acylated ethylene-olefin copolymer and a polyamine,
wherein the polyamine comprises at least two primary or secondary
amine functional groups.
DESCRIPTION OF THE EMBODIMENTS
[0010] As used herein, the terms "polymer" and "copolymer" is
understood to mean a polymer having more than one type of repeating
unit and include, for example, oligomers, copolymers, ethylene
copolymers, terpolymers, tetrapolymers and interpolymers. These
materials can contain minor amounts of other olefinic monomers so
long as the basic characteristics of the copolymers are not
materially changed. As used herein, the term "monomer" is
understood to mean a chemical compound or composition having an
olefin double bond present in the compound or composition.
[0011] The olefin copolymer substrate employed in the viscosity
index modifying copolymer of the present disclosure can be prepared
from ethylene and one or more C.sub.3 to C.sub.23 alpha-olefins,
for example copolymers of ethylene and propylene. Other
alpha-olefins include, but are not limited to, 1-butene, 1-pentene,
1-hexene, 1-octene, and styrene; .alpha.,.omega.-diolefins such as
1,5-hexadiene, 1,6-heptadiene, and 1,7-octadiene; branched chain
alpha-olefins such as 4-methylbutene-1,5-methylpentene-1, and
6-methylheptene-1; and mixtures thereof. Such alpha-olefins can
also be used in combination with ethylene and one or more C.sub.3
to C.sub.23 alpha-olefins to form a terpolymer. The acylated
copolymers of the present disclosure include, but are not limited
to, those described in U.S. Pat. No. 6,107,257, the disclosure of
which is herein incorporated by reference.
[0012] More complex polymer substrates, often designated as
interpolymers, can be prepared using another component.
Non-limiting examples of such a component generally used to prepare
an interpolymer substrate can be a polyene monomer, such as
non-conjugated dienes and trienes. The non-conjugated diene
component can have from about 5 to about 14 carbon atoms in the
chain. In an aspect, the diene monomer can be characterized by the
presence of a vinyl group in its structure and can include cyclic
and bicyclo compounds. Representative dienes include, but are not
limited to, 1,4-hexadiene, 1,4-cyclohexadiene, dicyclopentadiene,
5-ethylidene-2-norbornene, 5-methylene-2-norborene, 1,5-heptadiene,
and 1,6-octadiene. A mixture of more than one diene can be used in
the preparation of the interpolymer. In an embodiment, a
non-conjugated diene for preparing a terpolymer or interpolymer
substrate can be 1,4-hexadiene.
[0013] The triene component can have at least two non-conjugated
double bonds, and up to about 30 carbon atoms in the chain.
Non-limiting examples of typical trienes useful in preparing the
interpolymer of the disclosure include
1-isopropylidene-3.alpha.,4,7,7.alpha.-tetrahydroindene,
1-isopropylidenedicyclopentadiene, dihydro-isodicyclopentadiene,
and
2-(2-methylene-4-methyl-3-pentenyl)[2.2.1]bicyclo-5-heptene.
[0014] Ethylene-propylene or higher alpha-olefin copolymers can
comprise from about 15 to about 80 mole percent ethylene and from
about 20 to about 85 mole percent C.sub.3 to C.sub.23 alpha-olefin.
In an aspect, the proportions can range from about 35 to about 75
mole percent ethylene and from about 25 to about 65 mole percent of
a C.sub.3 to C.sub.23 alpha-olefin. In another aspect, the
proportions can range from about 50 to about 70 mole percent
ethylene and about 30 to about 50 mole percent C.sub.3 to C.sub.23
alpha-olefin. In yet another aspect, the proportions can range from
about 55 to about 65 mole percent ethylene and about 35 to about 45
mole percent C.sub.3 to C.sub.23 alpha-olefin.
[0015] Terpolymer variations of the foregoing polymers can contain
from about 0.1 to about 10 mole percent of a non-conjugated diene
or triene.
[0016] The ethylene-olefin polymer substrate can be an oil soluble,
linear or branched polymer having a number average molecular weight
ranging from about 10,000 to about 150,000, as determined by gel
permeation chromatography and universal calibration
standardization. In an embodiment, the number average molecular
weight of the ethylene-olefin copolymer ranges from about 20,000 to
about 45,000.
[0017] The polymerization reaction used to form the ethylene-olefin
copolymer substrate is generally carried out in the presence of a
conventional Ziegler-Natta or metallocene catalyst system. The
polymerization medium is not specific and can include solution,
slurry, or gas phase processes, as known to those skilled in the
art. When solution polymerization is employed, the solvent can be
any suitable inert hydrocarbon solvent that is liquid under
reaction conditions for polymerization of alpha-olefins; examples
of suitable hydrocarbon solvents include, but are not limited to,
straight chain paraffins having from about 5 to about 8 carbon
atoms. In an aspect of the present disclosure, hexane can be used
as a solvent. In another aspect, aromatic hydrocarbons, for
example, aromatic hydrocarbons having a single benzene nucleus,
such as benzene, toluene and the like; and saturated cyclic
hydrocarbons having boiling point ranges approximating those of the
straight chain paraffinic hydrocarbons and the aromatic
hydrocarbons described above, can be suitable solvents. The solvent
selected can be a mixture of one or more of the foregoing
hydrocarbons. In yet another aspect, when slurry polymerization is
employed, the liquid phase for polymerization can be liquid
propylene. It is desirable that the polymerization medium be free
of substances that will interfere with the catalyst components.
[0018] An ethylenically unsaturated carboxylic acid material is
next grafted onto the ethylene-olefin copolymer substrate backbone
to form an acylated ethylene-olefin copolymer. Carboxylic reactants
which are suitable for grafting onto the ethylene-olefin copolymer
can contain at least one ethylenic bond and at least one carboxylic
acid or its anhydride groups or a polar group which is convertible
into said carboxyl groups by oxidation or hydrolysis. In an aspect,
the carboxylic reactants can contain two carboxylic acid groups or
its anhydride groups or polar groups which are convertible into
said carboxyl groups by oxidation or hydrolysis. In another aspect,
the carboxylic reactants are selected from the group consisting of
acrylic, methacrylic, cinnamic, crotonic, maleic, fumaric and
itaconic reactants. In yet another aspect, the carboxylic reactants
are selected from the group consisting of maleic acid, fumaric
acid, maleic anhydride, or a mixture of two or more of these. In a
further aspect, maleic anhydride or a derivative thereof can be
suitable due to its commercial availability and ease of reaction.
In another aspect where unsaturated ethylene-olefin copolymers or
terpolymers are used, itaconic acid or its anhydride is can be
suitable due to its reduced tendency to form a cross-linked
structure during the free-radical grafting process.
[0019] The ethylenically unsaturated carboxylic acid materials
typically can provide one or two carboxylic groups per mole of
reactant to the grafted polymer. For example, methyl methacrylate
can provide one carboxylic group per molecule to the grafted
polymer while maleic anhydride can provide two carboxylic groups
per molecule to the grafted polymer.
[0020] The carboxylic reactant can be grafted onto the prescribed
polymer backbone in an amount to provide 0.3 to 0.75 carboxylic
groups per 1000 number average molecular weight units of the
polymer backbone. In an aspect, 0.3 to 0.5 carboxylic groups per
1000 number average molecular weight units can be used. For
example, a copolymer substrate with M.sub.n of about 20,000 can be
grafted with about 6 to about 10 carboxylic groups per polymer
chain, such as about 3 to about 5 moles of maleic anhydride per
mole of polymer. As a further example, a copolymer with M.sub.n of
about 100,000 can be grafted with about 30 to about 50 carboxylic
groups per polymer chain, such as about 15 to about 25 moles of
maleic anhydride per polymer chain. The minimum level of
functionality is the level needed to achieve the minimum
satisfactory dispersancy performance. Above the maximum
functionality level little, if any, additional dispersancy
performance is noted and other properties of the additive can be
adversely affected.
[0021] The grafting reaction to form the acylated ethylene-olefin
copolymers can generally carried out with the aid of a free-radical
initiator either in solution or in bulk, as in an extruder or
intensive mixing device. When the polymerization is carried out in
hexane solution, it is economically convenient to carry out the
grafting reaction in hexane as described in U.S. Pat. Nos.
4,340,689, 4,670,515 and 4,948,842, all of which are incorporated
herein by reference. The resulting polymer intermediate is
characterized by having carboxylic acid acylating functionality
randomly within its structure.
[0022] In the bulk process for forming the acylated ethylene-olefin
copolymers, the olefin copolymer is fed to rubber or plastic
processing equipment such as an extruder, intensive mixer or
masticator, heated to a temperature of about 150.degree. to about
400.degree. C. and the ethylenically unsaturated carboxylic acid
reagent and free-radical initiator are separately co-fed to the
molten polymer to effect grafting. The reaction is carried out
optionally with mixing conditions to effect shearing and grafting
of the ethylene copolymers according to U.S. Pat. No. 5,075,383,
incorporated herein by reference. The processing equipment is
generally purged with nitrogen to prevent oxidation of the polymer
and to aid in venting unreacted reagents and byproducts of the
grafting reaction. The residence time in the processing equipment
is sufficient to provide for the desired degree of acylation and to
allow for purification of the acylated copolymer via venting.
Mineral or synthetic lubricating oil can optionally be added to the
processing equipment after the venting stage to dissolve the
acylated copolymer.
[0023] The free-radical initiators which can be used to graft the
ethylenically unsaturated carboxylic acid material to the polymer
backbone include, but are not limited to, peroxides,
hydroperoxides, peresters, and also azo compounds. In an aspect,
free-radical initiators which have a boiling point greater than
about 100.degree. C. and decompose thermally within the grafting
temperature range to provide free radicals can be used.
Non-limiting representatives of these free-radical initiators are
azobutyronitrile, dicumyl peroxide,
2,5-dimethylhexane-2,5-bis-tertiarybutyl peroxide and
2,5-dimethyl-hex-3-yne-2,5-bis-tertiary-butyl peroxide. The
initiator can be used in an amount of from about 0.005% to about 1%
by weight based on the weight of the reaction mixture.
[0024] Other methods known in the art for effecting reaction of
ethylene-olefin copolymers with ethylenically unsaturated
carboxylic reagents, such as halogenation reactions, thermal or
"ene" reactions or mixtures thereof, can be used instead of the
free-radical grafting process. Such reactions are conveniently
carried out in mineral oil or bulk by heating the reactants at
temperatures of about 250.degree. to about 400.degree. C. under an
inert atmosphere to avoid the generation of free radicals and
oxidation byproducts. In an embodiment, "ene" reactions can be a
suitable method of grafting when the ethylene-olefin copolymer
contains unsaturation. To achieve the high graft levels, about 0.3
to about 0.5 carboxylic groups per 1000 M.sub.n, it can be
necessary to follow or proceed the "ene" or thermal graft reaction
with a free radical graft reaction.
[0025] The acylated ethylene-olefin copolymer intermediate can be
reacted with a polyamine compound. Suitable polyamines include
aromatic and non-aromatic polyamines containing at least two
primary or secondary amine functional groups Non-limiting examples
of suitable polyamines include 4,4-diaminodiphenylamine represented
by formula (I):
##STR00001##
wherein R.sup.1 and R.sup.2 are each independently H or alkyl group
comprising from about 1 to about 24 carbon atoms;
polytetrahydrofuran bis(aminopropyl) terminated; hexamethylene
diamine; bis(aminopropyl)piperazine; and phenylenediamine
represented by formula (II):
##STR00002##
wherein R.sup.1 and R.sup.2 are each independently H or alkyl group
comprising from about 1 to about 24 carbon atoms.
[0026] The reaction of the acylated ethylene-olefin copolymer
substrate intermediate and the polyamine compound can be conducted
by heating a solution of the polymer substrate under inert
conditions and then adding the polyamine compound to the heated
solution generally with mixing to effect the reaction. It can be
convenient to employ an oil solution of the polymer substrate
heated to about 140.degree. to about 175.degree. C., while
maintaining the solution under a nitrogen blanket. The polyamine
compound is added to this solution and the reaction can be effected
under the noted conditions.
[0027] Typically, the polyamine compound(s) can be dissolved in a
surfactant and added to a mineral or synthetic lubricating oil or
solvent solution containing the acylated ethylene-olefin copolymer.
This solution is heated with agitation under an inert gas purge at
a temperature in the range of about 120.degree. to about
200.degree. C. as described in U.S. Pat. No. 5,384,371, the
disclosure of which is herein incorporated by reference. The
reactions can be carried out conveniently in a stirred reactor
under nitrogen purge. However, it is also possible to add a
surfactant solution of the polyamine compound to zones downstream
from the graft reaction-vent zones in a twin screw extruder
reactor.
[0028] Surfactants which can be used in carrying out the reaction
of the acylated ethylene-olefin copolymer with the polyamine(s)
include, but are not limited to, those characterized as having (a)
solubility characteristics compatible with mineral or synthetic
lubricating oil, (b) boiling point and vapor pressure
characteristics so as not to alter the flash point of the oil and
(c) polarity suitable for solubilizing the polyamine(s). A suitable
non-limiting class of such surfactants includes the reaction
products of aliphatic and aromatic hydroxy compounds with ethylene
oxide, propylene oxide or mixtures thereof. Such surfactants are
commonly known as aliphatic or phenolic alkoxylates. Non-limiting
representative examples include mixtures of ethoxylated
C.sub.12-C.sub.16 linear primary alcohols, mixtures of C.sub.12 and
C.sub.13 linear primary alcohols, mixtures of C.sub.12-C.sub.15
linear primary alcohols, and nonylphenol ethoxylates. In an aspect,
surfactants include those surfactants that contain a functional
group, e.g., --OH, capable of reacting with the acylated
ethylene-olefin copolymer.
[0029] The quantity of surfactant used depends, in part, on its
ability to solubilize the polyamine. The surfactant can also be
added separately, instead of, or in addition to a concentrate, such
that the total amount of surfactant in a finished additive
concentrate can be about 10 wt. % or less.
[0030] The viscosity index modifying copolymers of the present
disclosure can be incorporated into a lubricating composition in
any convenient way. Thus, the viscosity index modifying copolymers
can be added directly to a lubricating oil by dispersing or
dissolving the same in the lubricating oil at the desired level of
concentration. Such blending into the lubricating oil can occur at
room temperature or elevated temperatures. In an aspect, the
lubricating composition can contain (on an active ingredient (A.I.)
basis) from about 0.1 to about 2.0 wt. %, for example from about
0.5 to about 1.0 wt. %, of the viscosity index modifying
copolymers.
[0031] Alternatively, the viscosity index modifying copolymers can
be blended with a suitable carrier or diluent oil to form an
additive concentrate, and then blending the concentrate with a
lubricating oil to obtain the final formulation. In an aspect, such
additive concentrates can contain (on an active ingredient (A.I.)
basis) from about 3 to about 45 wt. % viscosity index modifying
copolymer additive and from about 20 to about 90 wt % of a carrier
or diluent oil, based on the concentrate weight. In an aspect, such
additive concentrates can contain from about 10 to about 35 wt. %
viscosity index modifying copolymer additive and from about 40 to
about 60 wt % of a carrier or diluent oil, based on the concentrate
weight. The additive concentrates can also be blended with a
suitable oil soluble solvent, for example, but not limited to,
benzene, xylene, and toluene.
[0032] Suitable base oils for use herein include natural
lubricating oils, synthetic lubricating oils and mixtures thereof.
Base stocks obtained by isomerization of synthetic wax and slack
wax can also be suitable, as wells as base stocks produced by
hydrocracking (rather than solvent extracting) the aromatic and
polar components of the crude. In general, both natural and
synthetic base oils will each have a kinematic viscosity ranging
from about 1 to about 40 cSt at about 100.degree. C., although
typical applications can require each oil to have a viscosity
ranging from about 2 to about 20 cST at about 100.degree. C.
[0033] The American Petroleum Institute has categorized different
basestock types as follows: Group I, >0.03 wt. % sulfur, and/or
<90 vol % saturates, viscosity index between 80 and 120; Group
II, .ltoreq.0.03 wt. % sulfur, and .gtoreq.90 vol % saturates,
viscosity index between 80 and 120; Group III, .ltoreq.0.03 wt. %
sulfur, and .gtoreq.90 vol % saturates, viscosity index >120;
Group IV, all polyalphaolefins.
[0034] Suitable natural base oils include, but are not limited to,
animal oils, vegetable oils, (e.g., castor oil and lard oil),
petroleum oils, hydrorefined, solvent-treated or acid-treated
mineral lubricating oils of the paraffinic, napthenic and mixed
paraffinic-napthenic types. Oils derived from coal or shale are
also useful base oils. In one embodiment of the present disclosure,
the base oil used can be mineral oil.
[0035] The mineral oils useful in one embodiment of the present
disclosure include all common mineral oil base stocks. These
mineral oils include oils that are naphthenic or paraffinic in
chemical structure. Oils that are refined by conventional
methodology using acid, alkali, and clay or other agents such as
aluminum chloride can be used, or they can be extracted oils
produced by solvent extraction, for example, with solvents such as
phenol, sulfur dioxide, furfural, dichlordiethyl ether, etc. Such
oils can be hydrotreated or hydrorefined, dewaxed by chilling or
catalytic dewaxing processes, or hydrocracked. The mineral oil can
also be produced from natural crude sources or be composed of
isomerized wax materials or residues of other refining
processes.
[0036] Suitable synthetic lubricating base oils used in this
disclosure include one of any number of commonly used synthetic
hydrocarbon oils, which include, but are not limited to,
poly-alpha-olefins, alkylated aromatics, alkylene oxide polymers,
interpolymers, copolymers and derivatives thereof where the
terminal hydroxyl groups have been modified by esterification,
etherification etc., esters of dicarboxylic acids and silicon-based
oils.
[0037] For example, suitable synthetic base lubricating oils
include hydrocarbon oils and halo-substituted hydrocarbon oils such
as oligomerized, polymerized, and interpolymerized olefins (such as
polybutylenes, polypropylenes, propylene, isobutylene copolymers,
chlorinated polylactenes, poly(1-hexenes), poly(1-octenes) and
mixtures thereof); alkylbenzenes (including dodecyl-benzenes,
tetradecylbenzenes, dinonyl-benzenes and di(2-ethylhexyl)benzene);
polyphenyls (such as biphenyls, terphenyls and alkylated
polyphenyls); and alkylated diphenyl ethers, alkylated diphenyl
sulfides, as well as their derivatives, analogs, and homologs
thereof, and the like. In an embodiment, the synthetic base oils
are oligomers of alpha-olefins, particularly oligomers of 1-decene,
also known as polyalpha olefins or PAOs.
[0038] Suitable synthetic base lubricating oils also include
alkylene oxide polymers, interpolymers, copolymers, and derivatives
thereof where the terminal hydroxyl groups have been modified by
esterification, etherification, etc. This class of synthetic oils
is exemplified by: polyoxyalkylene polymers prepared by
polymerization of ethylene oxide or propylene oxide; the alkyl and
aryl ethers of these polyoxyalkylene polymers (e.g.,
methyl-polyisopropylene glycol ether having an average molecular
weight of 1000, diphenyl ether of polypropylene glycol having a
molecular weight of 100-1500); and mono- and poly-carboxylic esters
thereof (e.g., the acetic acid esters, mixed C.sub.3-C.sub.8 fatty
acid esters, and C.sub.12 oxo acid diester of tetraethylene
glycol).
[0039] Another suitable class of synthetic lubricating oils
comprises the esters of dicarboxylic acids (e.g., phthalic acid,
succinic acid, alkyl succinic acids and alkenyl succinic acids,
maleic acid, azelaic acid, subric acid, sebasic acid, fumaric acid,
adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids,
alkenyl malonic acids, etc.) with a variety of alcohols (e.g.,
butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl
alcohol, ethylene glycol, diethylene glycol monoethers, propylene
glycol, etc.). Specific examples of these esters include dibutyl
adipate, diisobutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl
fumarate, dioctyl sebacate, diisooctyl phthalate, diisooctyl
azelate, diisooctyl adipate, diisodecyl azelate, didecyl phthalate,
diisodecyl adipate, dieicosyl sebacate, the 2-ethylhexyl diester of
linoleic acid dimer, and the complex ester formed by reacting one
mole of sebasic acid with two moles of tetraethylene glycol and two
moles of 2-ethyl-hexanoic acid, and the like.
[0040] Esters useful as synthetic base oils also include those made
from C.sub.5 to C.sub.12 monocarboxylic acids and polyols and
polyol ethers such as neopentyl glycol, trimethylolpropane
pentaerythritol, dipentaerythritol, tripentaerythritol, and the
like.
[0041] Silicon-based oils (such as the polyalkyl-, polyaryl-,
polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils)
comprise another useful class of synthetic lubricating oils. These
oils include tetra-ethyl silicate, tetraisopropyl silicate,
tetra-(2-ethylhexyl)silicate,
tetra-(4-methyl-2-ethylhexyl)silicate,
tetra-(p-tert-butylphenyl)silicate,
hexa-(4-methyl-2-pentoxy)-disiloxane, poly(methyl)-siloxanes and
poly (methylphenyl)siloxanes, and the like. Other synthetic
lubricating oils include liquid esters of phosphorus containing
acids (e.g., tricresyl phosphate, trioctylphosphate, and diethyl
ester of decylphosphonic acid), polymeric tetra-hydrofurans,
poly-.alpha.-olefins, and the like.
[0042] Lubricating compositions containing an effective amount of
the viscosity index modifying copolymers described herein can be
used in numerous applications, including crankcase lubricating oils
for spark-ignited and compression-ignited internal combustion
engines, including, but not limited to, automobile and truck
engines, marine and railroad diesel engines, and the like.
Advantageous results can also be achieved by employing the additive
mixtures of the present disclosure in base oils conventionally
employed in and/or adapted for use as power transmission fluids,
continuously variable transmission fluids, manual transmission
fluids, hydraulic fluids, power steering fluids, shock absorber
fluids and the like. Gear lubricants, industrial oils, pump oils
and other lubricating oil compositions can also benefit from the
incorporation therein of the additive mixtures of the present
disclosure.
[0043] Lubricating compositions as disclosed herein can include
additives in addition to the viscosity index modifying copolymer of
the present disclosure. Non-limiting examples of additives that can
be included are additional viscosity index improvers, antioxidants,
corrosion inhibitors, detergents, dispersants, pour point
depressants, antiwear agents, antifoamants, demulsifiers, friction
modifiers, and the like.
[0044] According to an aspect of the present disclosure, there is
disclosed a method of improving boundary film resistance of a
lubricating composition, said method comprising providing a major
amount of an oil of lubricating viscosity, and a minor amount of an
additive composition comprising a viscosity index modifying
copolymer comprising the reaction product of an acylated
ethylene-olefin copolymer and a polyamine, wherein the polyamine
comprises at least two primary or secondary amine functional
groups
[0045] In another aspect, there is disclosed a method of modifying
the viscosity of a lubricating composition, said method comprising
providing a major amount of an oil of lubricating viscosity, and
mixing with said oil a minor amount of an additive composition
comprising a viscosity index improving copolymer comprising the
reaction product of an acylated ethylene-olefin copolymer and a
polyamine, wherein the polyamine comprises at least two primary or
secondary amine functional groups.
[0046] In a further aspect, there is disclosed a method of
lubricating an automotive engine, said method comprising adding to
and operating in the crankcase of the automotive engine a
lubricating composition comprising a major amount of an oil of
lubricating viscosity and a minor amount of an additive composition
comprising a viscosity index improving copolymer comprising the
reaction product of an acylated ethylene-olefin copolymer and a
polyamine, wherein the polyamine comprises at least two primary or
secondary amine functional groups.
[0047] Additionally, there is disclosed a method of improving the
low temperature properties of a lubricating oil, said method
comprising combining an oil of lubricating viscosity and an olefin
copolymer composition comprising the reaction product of an
acylated ethylene-olefin copolymer and a polyamine, wherein the
polyamine comprises at least two primary or secondary amine
functional groups.
[0048] The acylated ethylene-olefin copolymers of the present
disclosure can be post-treated so as to impart additional
properties necessary or desired for a specific lubricant
application. Post-treatment techniques are well known in the art
and include, but are not limited to, boronation, phosphorylation,
and maleination.
EXAMPLES
[0049] The following non-limiting examples are given to illustrate
aspects of the disclosed embodiments with respect to the
preparation of the multi-functional olefin copolymers of the
present disclosure. The examples are not intended to limit the
embodiments as disclosed herein. In these examples, as well as
elsewhere in this application, all parts and percentages are by
weight of the composition, unless otherwise indicated.
Example 1
[0050] An acylated ethylene-propylene copolymer was prepared by
free radically grafting maleic anhydride, in the presence of a
solvent, onto an ethylene-propylene copolymer backbone. The
acylated ethylene-propylene copolymer had a number average
molecular weight (M.sub.n) of approximately 40,000 as determined by
gel permeation chromatography. The reaction conditions and molar
proportions of maleic anhydride and ethylene-propylene copolymer
were such that 7.2 molecules of maleic anhydride were grafted onto
the olefin copolymer backbone. This is equivalent to 0.43
carboxylic groups per 1000 M.sub.n of polymer backbone (e.g.,
2.times.5=10 carboxylic groups/23,000 M.sub.n=0.43 carboxylic
groups/1000 M.sub.n) to form the acylated ethylene-propylene
copolymer.
[0051] 186.7 g solution of the acylated ethylene-propylene
copolymer containing about 25% polymer and 75% process oil was
charged to a reaction vessel equipped with a nitrogen sparge and
Dean-Stark trap, followed by an additional 299.4 g of process oil.
The mixture was heated to about 140.degree. C. To this mixture, 2.2
g of a molten-blend was poured in. The molten-blend was prepared by
mixing 1.1 g of N-phenyl-phenylenediamine and 1.1 g of a surfactant
(Surfonic L24-2, available from Huntsman Corp. of The Woodlands,
Tex.) and heating in an oven at 80.degree. C. The resulting mixture
was agitated at 140.degree. C. for 2 hrs. At this point, 0.42 g of
another molten-blend was poured in. This molten-blend was prepared
by mixing 0.21 g of 1,3-phenylenediamine and 0.21 g of the above
surfactant and heating in an oven at 80.degree. C. The resulting
mixture was agitated at 140.degree. C. for 2 hrs, followed by
160.degree. C. for 2 hrs. The product thus obtained had 0.041%
nitrogen content and had a kinemetic viscosity of 212 cst at
100.degree. C.
[0052] The reaction product of Example 1 was blended into a heavy
duty diesel 15W-40 formulation, listed in Table 1 below as
Inventive Formulation 2. This formulation contained 10 wt. % of the
reaction product of Example I. As a comparison formulation,
Comparative Formulation 1 was formulated using the same type of
base oil except containing 10 wt. % of a conventional OCP viscosity
index improver (OCP VII). The resulting blend viscometrics and the
film formation properties of these lubricating fluids were
determined utilizing a High Frequency Reciprocating Rig (HFRR) (see
SAE 2002-01-2793 "Film Formation Properties of Polymers in the
Presence of Abrasive Contaminants" by Mark T. Devlin et al.)
[0053] For the HFRR film test, 6% of carbon black was added to the
fluids and 1-2 mL of the fluids were placed in the HFRR cell.
During the test, the ball was oscillated across the disk at a
frequency of 20 Hz over a 1 mm path. A load of 0.1 N was applied
between the ball and the disk during the test, which lasted for 10
minutes. The formation of boundary film was measured throughout the
10 minute test, and the average film measurement (percent
resistance) was reported. A boundary film is formed when the ball
and disk are separated, and the current running between the ball
and disk is reduced and can be recorded as a percent resistance.
The higher the percent resistance, the more tenacious the boundary
film. The results of the HFRR test are displayed in Table 1
below.
TABLE-US-00001 TABLE 1 Comparative Inventive Formulation I
Formulation II Core Pack 6.90% 6.90% 1300 MW.sub.N PIB dispersant,
2.50% 2.50% post treated with maleic anhydride and boric acid 2100
MW.sub.N PIB dispersant 5.73% 5.73% OCP VII 10.00% 0.00% VII of
Example 1 0.00% 10.00% Base oil remainder remainder KV @
100.degree. C. 17.35 17.53 HFRR film measurement 17 .+-. 5% 68.5
.+-. 0.5% (average of 2 runs)
[0054] As the results in Table I indicate, the viscosity index
modifying product of this disclosure (inventive Formulation II)
gave comparable thickening to the oil as compared to Comparative
Formulation I (indicated by the kinematic viscosity (KV) of the
formulations) and produced a much more tenacious boundary film
(68.5.+-.0.5%), as compared 17.+-.5% for Comparative Formulation
I.
[0055] At numerous places throughout the specification, reference
has been made to a number of U.S. patents. All such cite documents
are expressly incorporated in full into this disclosure as if fully
set forth herein.
[0056] This disclosure is susceptible to considerable variation in
its practice. Accordingly, this disclosure is not limited to the
specific exemplifications set forth hereinabove. Rather, this
disclosure is within the spirit and scope of the appended claims,
including the equivalents available as a matter of law. Other
embodiments of the present disclosure will be apparent to those
skilled in the art from consideration of the specification and
practice of the embodiments disclosed herein.
[0057] As used throughout the specification and claims, "a" and/or
"an" can refer to one or more than one. Unless otherwise indicated,
all numbers expressing quantities of ingredients, properties such
as molecular weight, percent, ratio, reaction conditions, and so
forth used in the specification and claims are to be understood as
being modified in all instances by the term "about." Accordingly,
unless indicated to the contrary, the numerical parameters set
forth in the specification and claims are approximations that can
vary depending upon the desired properties sought to be obtained by
the present disclosure. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques. Notwithstanding that the
numerical ranges and parameters setting forth the broad scope of
the disclosed embodiments are approximations, the numerical values
set forth in the specific examples are reported as precisely as
possible. Any numerical value, however, inherently contains certain
errors necessarily resulting from the standard deviation found in
their respective testing measurements. It is intended that the
specification and examples be considered as exemplary only, with a
true scope and spirit of the embodiments being indicated by the
following claims.
[0058] The patentees do not intend to dedicate any disclosed
embodiments to the public, and to the extent any disclosed
modifications or alterations may not literally fall within the
scope of the claims, they are considered to be part of the
disclosure under the doctrine of equivalents.
* * * * *