Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
POLYMERIC DISPERSANT VISCOSITY MODIFIER COMPOSITION
FIELD OF INVENTION
The present invention relates to a composition containing a polymeric
dispersant viscosity modifier; and an amine salt of a phosphorus compound.
The invention further provides a process for making the composition and a
method for lubricating a gear or bearing surface with the composition.
BACKGROUND OF THE INVENTION
Oxidation of an oil of lubricating viscosity, especially an organic
petroleum fluid, occurs in the presence of oxygen which leads to increased
viscosity and sludge and/or deposit formation. Sludge and/or deposit formation
is produced by a number of different mechanisms such as degradation of oil
and decomposition products of lubricant additives. Using known lubricant
additives containing an amine salt of a phosphorus compound such as many
antiwear agents and friction modifiers are believed to contribute to the
formation of sludge and/or deposit formation. The presence of sludge and other
deposits interferes with seal performance leading to leakage and ultimately
equipment failure for gears or bearings.
Polymeric dispersant viscosity modifier are added to lubricating
compositions to impart resistance to rust, improved cleanliness, improved
viscosity modifying properties and decreased sludge accumulation. The
polymeric dispersant viscosity modifier is generally a nitrogen containing
poly(meth)acrylate, a nitrogen containing polyolefin or a nitrogen containing
esterifled styrene-maleic anhydride interpolymer.
US Patent number 6,124,249 (Seebauer et al.) discloses a dispersant
viscosity improving copolymer derived from (a) a nitrogen containing
monomer; and (b) methacrylic acid esters containing from about 9 to about 25
carbon atoms in the ester group.
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US Patent Number 6,586,375 (Gahagan et al.) discloses a lubricant
composition containing a nitrogen containing polyacrylate salted with a
phosphorus acid ester. The lubricant composition provides improved
dispersant, viscosity improver and antiwear properties.
It is desirable to have a composition capable of decreasing sludge
accumulation. The present invention provides a composition capable of
decreasing sludge accumulation.
It is desirable to have a composition with deposit control. The present
invention provides a composition with deposit control.
SUMMARY OF THE INVENTION
The present invention is a composition comprising:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group;
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
3) mixtures thereof.
The invention further provides a method comprising lubricating a
surface while. imparting deposit control, the method employing a composition
comprising:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
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1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group;
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
3) mixtures thereof, wherein the surface is a gear, a bearing or
mixtures thereof.
The invention further provides a process for the preparation of a
composition comprising mixing:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group;
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
3) mixtures thereof.
The use of the composition of the invention is capable of imparting one
or more performance characteristics including deposit control, reduced carbon
varnish, decreased wear, low temperature viscometrics, high temperature
viscometrics or mixtures thereof.
DETAILED DESCRIPTION OF THE INVENTION
A composition comprising:
(a) an oil of lubricating viscosity;
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(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group;
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
3) mixtures thereof.
In one embodiment the invention provides a composition comprising:.
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a polymeric dispersant viscosity modifier,
wherein the polymeric dispersant viscosity modifier excludes
copolymers derived from (a) a nitrogen containing monomer; (b)
methacrylic acid esters containing from about 9 to about 25 carbon
atoms in the ester group.
In one embodiment the invention further provides a composition comprising:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound;
(c) a polymeric dispersant viscosity modifier;
(d) a borated dispersant; and
(e) a sulphurised olefin.
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Oil of Lubricating ViscositX
The lubricating oil composition includes natural or synthetic oils of
lubricating viscosity, oil derived from hydrocracking, hydrogenation,
hydrofinishing, unrefined, refined and re-refined oils or mixtures thereof.
Natural oils include animal oils, vegetable oils, mineral oils or mixtures
thereof. Synthetic oils include a hydrocarbon oil, a silicon-based oil, a
liquid
esters of phosphorus-containing acid. Synthetic oils may be produced by
Fischer-Tropsch reactions and typically may be hydroisomerised Fischer-
Tropsch hydrocarbons or waxes
Oils of lubricating viscosity may also be defined as specified in the
American Petroleum Institute (API) Base Oil Interchangeability Guidelines. In
one embodiment the oil of lubricating viscosity comprises an API Group I, II,
III, IV, V, VI or mixtures thereof, and in one embodiment API Group I, II, III
or mixtures thereof. If the oil of lubricating viscosity is an API Group II,
III,
IV, V or VI oil there may be up to about 40 wt % and in another embodiment
up to a maximum of about 5 wt % of the lubricating oil an API Group I oil.
The oil of lubricating viscosity is present at up to about 99.9 wt % of the
composition, in another embodiment up to about 98.9 wt % of the composition,
in another embodiment up to about 96.8 wt % of the composition and in yet
another embodiment up to about 94.8 wt % of the composition. In one
embodiment of the invention the oil of lubricating viscosity is present from
about 30 wt % to about 99.9 wt % of the composition, in another embodiment
about 45 wt % to about 94.8 wt % and in another embodiment about 60 wt % to
about 90 wt % of the composition.
In one embodiment the invention is in the form of a concentrate (which
can be combined with additional oil to form, in whole or in part, a finished
lubricant), the ratio of each of the above-mentioned polymeric dispersant
viscosity modifier and an amine salt of a phosphorus compound, as well as
other components, to diluent oil in the range from about 80:20 to about 10:90
by weight.
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Amine Salt of Phosphorus Compound
The invention further includes an amine salt of a phosphorus compound.
The amine salt of a phosphorus compound includes an extreme pressure agent,
a wear preventing agent, a friction modifier or mixtures thereof. In one
embodiment of the invention the amine salt of a phosphorus compound further
comprises a sulphur atom in the molecule. In one embodiment of the invention
the amine salt of a phosphorus compound is ashless i.e. metal-free.
The amine includes a primary amine, a secondary amine, a tertiary
amine or mixtures thereof. The amine includes those with at least one
hydrocarbyl group, in another embodiment about two hydrocarbyl groups and
in another embodiment about three hydrocarbyl groups. The hydrocarbyl group
contains a number of carbon atoms including those in the range from about 2 to
about 30, in another embodiment about 8 to about 26, in another embodiment
about 10 to about 20, and in yet another embodiment about 13 to about 19.
Primary amines include ethylamine, propylamine, butylamine, 2-
ethylhexylamine, octylamine and dodecylamine. Also suitable primary fatty
amines which include n-octylamine, n-decylamine, n-dodecylamine, n-
tetradecylamine, n-hexadecylamine, n-octadecylamine an.d 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.
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.
.The amine may also be a tertiary-aliphatic primary amine. The aliphatic
group includes an alkyl group containing a number of carbon atoms from 2 to
30, in another embodiment 6 to 26 and in another embodiment 8 to 24. The
tertiary alkyl amines include a monoamine such as tert-butylamine,
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terthexylamine, 1-methyl-1 -amino-cyclohexane, tert-octylamine, tert-
decylamine, tertdodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-
octadecylamine, terttetracosanylamine, or tert-octacosanylamine.
The amine salt of a phosphorus compound also includes phosphoric acid
esters or salt thereof; dialkyldithiophosphoric acid esters or salt thereof;
phosphites; and phosphorus-containing carboxylic esters, ethers, and amides or
mixtures thereof.
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.
In one embodiment of the invention the amine salt of a phosphorus
compound is a friction modifier. Examples of a suitable friction modifier
include amine salts of alkylphosphoric acids other than the wear preventing
agent.
The amine salt of a phosphorus compound is present in one embodiment
in range from about 0 wt % to about 30 wt % of the composition, in another
embodiment from about 0.001 wt % to 30 wt % of the composition, in another
embodiment from about 0.1 wt % to about 20 wt % of the composition, in
another embodiment from about 0.5 wt % to about 15 wt % of the composition
and in another embodiment from about 1 wt % to about 10 wt % of the
composition.
Polymeric Dispersant Viscosity Modifier
As used hereinafter the term "(meth)acrylate" is used to refer to a
methacrylate and a acrylate; and "(meth)acrylamide" is used to refer to a
acrylamide and a methacrylamide..
The polymeric dispersant viscosity modifier includes a (co)polymer with
a nitrogen containing monomer, a nitrogen containing compound capable of
reacting with a functionalised polymer backbone or mixtures thereof. The
polymeric dispersant viscosity modifier includes those derived from at least
one
polymer including a poly(meth)acrylate copolymer, a functionalised polyolefin,
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an esterified polymer derived from: (i) a vinyl aromatic monomer; and (ii) an
unsaturated carboxylic acid or derivatives thereof; or mixtures thereof.
The nitrogen containing monomer includes a vinyl substituted nitrogen
heterocyclic monomer, a dialkylaminoalkyl (meth)acrylate monomer, a
dialkylaminoalkyl (meth)acrylamide monomer, a tertiary-(meth)acrylamide
monomer and mixtures thereof. The alkyl contains 1 to about 8, or from 1 to
about 3 carbon atoms.
Useful nitrogen containing monomers include vinyl pyridine, N-vinyl
imidazole, N-vinyl pyrrolidinone, and N-vinyl caprolactam,
dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate,
dimethylaminobutylacrylamide dimethylamine propyl methacrylate,
dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide,
dimethylaminoethylacrylamide, tertiary butyl acrylamide or mixtures thereof.
The nitrogen containing compound includes an amine such as a
monoamine, a polyamine or mixtures thereof. The amine includes primary
functionality, secondary functionality or mixtures thereof. The amine includes
cyclic, linear or branched and examples include an alkylenemonoamine, a
heterocyclic monoamine, an alkylenepolyamine, a heterocyclic polyamine or
mixtures thereof. In one embodiment the amine contains not more than one
primary or secondary amino group, for example N,N-
dimethylaminopropylamine.
In one embodiment the. amine may be a hydroxy-substituted hydrocarbyl
amine such as a hydroxyalkyl amine. Examples of a suitable hydroxy-
substituted hydrocarbyl amine include aminoethyl ethanolamine, aminopropyl
ethanolamine, aminobutyl ethanolamine or mixtures thereof.
In one embodiment the amine includes compounds that are represented by the
formula:
(D-(R,) y N- -", R ~)
R4
wherein
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w is the number of R3 atoms, including ranges from about 4 to about 16
atoms, in another embodiment about 5 to about 12 atoms, and in another
embodiment 5 to about 8 atoms;
y is the number of carbon atoms associated with R2, including ranges
from 1 to about 8, in another embodiment 1 to about 6, and in another
embodiment about 2 to about 5 carbon atoms;
Rl is independently an atom including carbon, oxygeii, nitrogen,
phosphorus or mixtures thereof;
R2 is an alkyl or an alkenyl group with containing y carbon atoms,
especially useful examples of R 2 include ethyl, propyl or mixtures thereof;
and
R3 and R4 are independently hydrogen or a hydrocarbyl group, in
another embodiment at least one is hydrogen, and in another embodiment both
are hydrogen.
When R3 or R4 is a hydrocarbyl group, the number of carbon atoms
present is in the range from 1 to about 8, in another embodiment in the range
from 1 to about 5 and in another embodiment in the range from 1 to about 3.
Examples of a hydrocarbyl group include methyl, ethyl, propyl, butyl, pentyl
or
mixtures thereof.
Formula (I) represents a compound that includes a mononuclear cyclic
structure, a polynuclear cyclic structure or mixtures thereof. When formula
(I)
represents a mononuclear structure, w in one embodiment ranges from about 5
to about 8 and in another embodiment about 6 to about 7. When formula (I)
represents a polynuclear cyclic structure w in one embodiment ranges from
about 8 to about 16 and in another embodiment about 10 to about 12. The
cyclic ring includes aromatic, non-aromatic or mixtures thereof, although a
non-aromatic ring is especially useful.
Suitable cyclic amines include 4-aminodiphenylamine, 4-(3-
aminopropyl) morpholine, 4-(2-aminoethyl) morpholine or mixtures thereof. In
one embodiment the cyclic amine is 4-(3-aminopropyl) morpholine or mixtures
thereof.
The polymeric dispersant viscosity modifier is also derived from at least
one polymer including a poly(meth)acrylate, a functionalised polyolefin, an
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esterified polymer derived from: (i) a vinyl aromatic monomer; and (ii) an
unsaturated carboxylic acid or derivatives thereof; or mixtures thereof. In
one
embodiment the poly(meth)acrylate further contains a nitrogen containing
monomer.
The poly(meth)acrylate polymeric dispersant viscosity modifier includes
a copolymer derived from a (meth)acrylate monomer containing an alkyl group
with 1 to 30 carbon atoms, in another embodiment 1 to 26 carbon atoms and in
another embodiment 1 to 20 carbon atoms. The alkyl group includes mixtures
derived from an alcohol containing 1 to about 4 carbon atoms, about 8 to about
10 carbon atoms, about 12 to about 14 carbon atoms, about 12 to about 15
carbon atoms, about 16 to about 18 carbon atoms or about 16 to about 20
carbon atoms. Examples of commercially available alcohol mixtures include
the following products sold under the brand names of DobanolTM 25, NeodolTM
25, LialTM 125, and AlchemTM 125. In one embodiment the alcohol is a single
alcohol i.e. not a mixture.
The (meth)acrylate monomer includes those derived from natural or
synthetic sources. When derived by synthetic sources the (meth)acrylate
monomer may be prepared using known direct esterification and/or
transesterification processes.
In one embodiment the poly(meth)acrylate polymeric dispersant
viscosity modifier is derived from a methyl (meth)acrylate monomer and at
least one other (meth)acrylate monomer including an alkyl group with about 8
to about 20 carbon atoms, in another embodiment about 10 to about 18 carbon
atoms and in another embodiment about 12 to about 15 carbon atoms. The
methyl (meth)acrylate monomer is in the range from about 1 wt % or more of
the poly(meth)acrylate, in another embodiment in the range from about 8 wt %
or more of the poly(meth)acrylate and in another embodiment in the range from
about 10 wt % or more of the poly(meth)acrylate. Upper limits on the amount
of methyl (meth)acrylate include about 40 wt % of the poly(meth)acrylate, in
another embodiment about 30 wt % of the poly(meth)acrylate and in another
embodiment about 20 wt % of the poly(meth)acrylate.
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In one embodiment the composition containing the polymeric dispersant
viscosity modifier excludes copolymers derived from (a) a nitrogen containing
monomer; and (b) methacrylic acid esters containing from about 9 to about 25
carbon atoms in the ester group. In another embodiment the composition
containing the polymeric dispersant viscosity modifier further excludes a salt
of
a phosphorus acid ester and a nitrogen containing polyacrylate.
As described hereinafter the molecular weight of the polymeric
dispersant viscosity modifier has been determined using known methods, such
as GPC analysis using a polystyrene standard.
The poly(meth)acrylate has a molecular weight (Mw,) including from
about 5000 to about 350,000, in another embodiment about 10,000 to about
150,000, in another embodiment about 15,000 to about 120,000, in another
embodiment about 10,000 to about 50,000 and in yet another embodiment about
15,000 to about 35,000.
The polymeric dispersant viscosity modifier derived from a
functionalised polyolefin and/or an esterified polymer contain an unsaturated
carboxylic acid or derivatives thereof. The carboxylic acid or derivatives
thereof includes a mono- acid, a di-acid or mixtures thereof. Optionally the
unsaturated carboxylic acid or derivatives thereof is further substituted with
a
hydrocarbyl group. The hydrocarbyl group includes substituted, unsubstituted,
branched, unbranched or mixtures thereof, although, unsubstituted is
especially
useful.
The unsaturated carboxylic acid anhydride or derivatives thereof may be
wholly esterified, partially esterified or mixtures thereof. When partially
esterified other derivatives 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 an
acrylic acid, a methyl acrylate, a methacrylic acid, a maleic acid or
anhydride, a
fumaric acid, an itaconic acid or anhydride or mixtures thereof.
Suitable examples of the unsaturated dicarboxylic acid anhydride or
derivatives include itaconic anhydride, maleic anhydride, methyl maleic
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anhydride, ethyl maleic anhydride, dimethyl maleic anhydride or mixtures
thereof. The unsaturated carboxylic acid anhydride or derivatives thereof
functionality may be used alone or in combination.
In one embodiment the polymeric dispersant viscosity modifier is a
functionalised polyolefin. In one embodiment the functionalised polyolefin
further contains a nitrogen derived from a nitrogen containing compound
capable of reacting with a functionalised polymer backbone.
In one embodiment the functionalised polyolefin is derived from an
ethylene monomer and at least one other comonomer derived from an alpha-
olefin having the formula H2C=CHR5, wherein R5 is a hydrocarbyl group,
especially an alkyl radical containing 1 to about 18 carbon atoms, in another
embodiment 1 to about 10 carbon atoms, in another embodiment 1 to about 6
carbon atoms and in yet another embodiment 1 to about 3 carbon atoms. The
hydrocarbyl group includes an alkyl radical that has a straight chain, a
branched
chain or mixtures thereof. Examples of a comonomer include propylene, 1-
butene, 1-hexene, 1-octene, 4-methyl-l-pentene, 1-decene or mixtures thereof.
In one embodiment the comonomer includes 1-butene, propylene or mixtures
thereof. Examples of the olefin copolymers include ethylene-propylene
copolymers, ethylene-l-butene copolymers or mixtures thereof.
In another embodiment the alpha-olefin includes a comonomer with
about 6 to about 40 carbon atoms, in another embodiment about 10 to about 34
carbon atoms, and in another embodiment about 14 to about 22 carbon atoms.
Examples of an alpha-olefin include 1-decene 1-undecene, 1-dodecene, 1-
tridecene, 1-butadecene, 1-pentadecene, 1-hexadecene, 1-heptadecene 1-
octadecene, 1-nonadecene, 1-eicosene, 1-doeicosene, 2-tetracosene, 3-methyl-
1-henicosene, 4-ethyl-2-tetracosene or mixtures thereof. Useful examples of an
alpha-olefin include 1-pentadecene, 1-hexadecene, 1-heptadecene 1-
octadecene, 1-nonadecene or mixtures thereof. The alpha-olefin is often
commercially available as mixtures especially as C16-C18.
In one embodiment the polymeric dispersant viscosity modifier is
derived from functionalised polyolefin, functionalised with an unsaturated
carboxylic acid anhydride or derivatives thereof (described above). The
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functionalised polyolefin has a molecular weight (M,) in the range including
from about 600 to about 300,000, in another embodiment about 600 to about
100,000, in another embodiment about 1000 to about 50,000 and in another
embodiment about 2000 to about 20,000.
The unsaturated carboxylic acid anhydride or derivatives thereof may be
incorporated into olefin polymer backbone and/or grafted on to the backbone.
In one embodiment the unsaturated carboxylic acid anhydride or derivatives
thereof is grafted on to the backbone. In one embodiment the unsaturated
carboxylic acid anhydride or derivatives thereof is incorporated into olefin
polymer backbone.
In one embodiment the polymeric dispersant viscosity modifier is an
esterified polymer derived from monomers comprising: (i) a vinyl aromatic
monomer; and (ii) an unsaturated carboxylic acid or derivatives thereof. The
polymer prior to esterification is generally referred to as an interpolymer.
In
one embodiment the esterified polymer is substantially free of to free of a
(meth)acrylate ester. In one embodiment the interpolymer is a styrene-maleic
anhydride copolymer. In one embodiment the esterified polymer contains a
nitrogen derived from a nitrogen containing compound capable of reacting with
a functionalised polymer backbone to form an amidated polymer.
The molecular weight of the interpolymer may also be expressed in
terms of the "reduced specific viscosity" of the polymer which is recognized
means of expressing the molecular size of a polymeric substance. As used
herein, the reduced specific viscosity (abbreviated as RSV) is the value
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 about lg of the
polymer in about 10 cm3 of acetone and the viscosity of acetone at about 30 C.
For purpose of computation by the above formula, the concentration is adjusted
to about 0.4g of the interpolymer per 10 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 an
interpolymer, appears in Paul J. Flory, Principles of Polymer Chemistry, (1953
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Edition) pages 308 et seq. The interpolymer polymer of the invention has a
RSV from about 0.05 to about 2 in one embodiment about 0.06 to about 1 and
in another embodiment about 0.06 to about 0.8. In one embodiment the RSV is
about 0.69. In another embodiment the RSV is about 0.12. In one embodiment
the Mw of the interpolymer is about 10,000 to about 300,000.
Examples of a vinyl aromatic monomer include styrene (often referred
to as ethenylbenzene), substituted styrene or mixtures thereof. Substituted
styrene monomers include functional groups such as a hydrocarbyl group,
halo-, amino-, alkoxy-, carboxy-, hydroxy-, sulphonyl- or mixtures thereof.
The functional groups include those located at the ortho, meta or para
positions
relative to the vinyl group on the aromatic monomer, the functional groups are
located at the ortho or para position being especially useful. In one
embodiment the functional groups are located at the para position. Halo-,
functional groups include chlorine, bromine, iodine or mixtures thereof. In
one
embodiment the halo functional group is chlorine or mixtures thereof. Alkoxy
functional groups may contain 1 to about 10 carbon atoms, in another
embodiment 1 to about 8 carbon atoms, in another embodiment 1 to about 6
carbon atoms and in yet another embodiment 1 to about 4 carbon atoms.
Alkoxy functional groups containing 1 to about 4 carbon atoms is referred to
as
lower alkoxy styrene.
The hydrocarbyl group includes ranges from 1 to about 30 carbon atoms,
in another embodiment 1 to about 20 carbon atoms, in another embodiment 1 to
about 15 carbon atoms and in yet another embodiment 1 to about 10 carbon
atoms. Examples of a suitable hydrocarbyl group on styrene monomers include
alpha-methylstyrene, para-methylstyrene (often referred to as vinyl toluene),
para-tert-butylstyrene, alpha-ethylstyrene, para-lower alkoxy styrene or
mixtures thereof.
The polymeric dispersant viscosity modifier is known in the art and
commercially available from a number of corporations, including The Lubrizol
Corporation, Degussa AG and Rohmax GmbH.
The polymeric dispersant viscosity modifier is present in the range from
about 0.001 wt % to about 60 wt % of the composition, in another embodiment
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about 1 wt % to about 50 wt % of the composition, in another embodiment
about 2 wt % to about 40 wt % of the composition and in another embodiment
about 5 wt % to about 35 wt % of the composition.
Other Performance Additive
The composition of the invention optionally includes at least one other
performance additive. The other performance additive includes a metal
deactivator, a detergent, a dispersant, an extreme pressure agent, an antiwear
agent, an antioxidant, a corrosion inhibitor, a foam inhibitor, a
demulsifiers, a
pour point depressant, a seal swelling agent or mixtures thereof.
The total combined amount of the other performance additive present on
an oil free basis is present in the range from about 0 wt % to about 25 wt %,
in
another embodiment about 0.01 wt % to about 20 wt %, in another embodiment
about 0.1 wt % to about 15 wt % and in yet another embodiment about 0.5 wt
% to about 10 wt % of the composition. Although one or more of the other
performance additives may be present, it is common for the other performance
additives to be present in different amounts relative to each other.
Antiwear Agent
Optionally, the composition includes an antiwear agent. The antiwear
agent may also act as an extreme pressure agent for example a sulphurised
olefin. The antiwear agent may be used alone or in combination. In one
embodiment the antiwear agent includes a thiocarbamate-containing compound
such as thiocarbamate esters, thiocarbamate amides, thiocarbamic ethers,
alkylene-coupled thiocarbamates, or bis(S-alkyldithiocarbamyl) disulphides. In
one embodiment the thiocarbamate-containing compound is present. In one
embodiment the thiocarbamate-containing compound is not present.
The dithiocarbamate containing compounds may be prepared by reacting
a dithiocarbamate acid or salt with an unsaturated compound. The
dithiocarbamates 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.
US Patents 4,758,362 and 4,997,969 describe dithiocarbamate compounds and
methods of making them.
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In one embodiment the antiwear agent includes a fatty amine. Useful
fatty amine compounds include those commercially available as "Armeen"
(RTM) amines (products available from Akzo Chemicals, Chicago, Illinois),
such as Akzo's, 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. In one embodiment the
fatty amine is present. In one embodiment the fatty amine is not present.
In one embodiment the antiwear agent includes a sulphurised olefin.
Examples of the sulphurised olefin include an olefin derived from propylene,
isobutylene, pentene, an organic sulphide and/or polysulphide including
benzyldisulphide; bis-(chlorobenzyl) disulphide; dibutyl, tetrasulphide; di-
tertiary butyl polysulphide; and sulphurised methyl ester of oleic acid, a
sulphurised alkylphenol, a sulphurised dipentene, a sulphuris'ed terpene, a
sulphurised Diels-Alder adduct, an alkyl sulphenyl N'N-dialkyl
dithiocarbamates; or mixtures thereof. In one embodiment the sulphurised
olefin includes an olefin derived from propylene, isobutylene, pentene or
mixtures thereof. In one embodiment the sulphurised olefin is present. In one
- embodiment the sulphurised olefin is not present.
In one embodiment the antiwear agent includes a phosphosulphurised
' hydrocarbon. Examples include a dithiophosphate, the reaction product of
phosphorus sulphide with turpentine and/or methyl oleate; a phosphorus ester
including a dihydrocarbon and/or a trihydrocarbon phosphite, e.g., dibutyl
phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite;
dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and
polypropylene substituted phenol phosphite; or mixtures thereof.
In one embodiment the antiwear agent includes phosphorus antiwear
compounds similar to the amine salt of a phosphorus compound described
above, except the amine salt has been replaced partially or wholly by a
valence
of a metal to form a metal salt. The valence of metal includes an alkali
metal,
alkaline earth metal, a transition metal or mixtures thereof. Examples of a
metal include sodium, potassium, lithium, calcium, magnesium, barium, zinc or
mixtures thereof.
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In one embodiment the antiwear agent includes a metal hydrocarbyl
dithiophosphate. Examples of a metal hydrocarbyl dithiophosphate include
zinc dihydrocarbyl dithiophosphates (often referred to as ZDDP, ZDP or
ZDTP). Examples of suitable zinc hydrocarbyl dithiophosphates compounds
may include the reaction product(s) of heptyl or octyl or nonyl
dithiophosphoric acids with ethylene diamine, morpholine or mixtures thereof.
The antiwear agent is present in ranges including from about 0 wt % to about
30 wt % of the composition, in another embodiment about 0.001 wt % to 30 wt
% of the composition, in another embodiment from about 0.05 wt % to about 20
wt % of the composition, in another embodiment from about 1 wt % to about 15
wt % of the composition and in another embodiment from about 0.5 wt % to
about 10 wt % of the composition.
Dispersant
In one embodiment of the invention the composition further includes a
dispersant. The dispersant may be used alone or in combination with other
dispersant additives. The dispersant includes those derived from a N-
substituted long chain alkenyl succinimide.
The N-substituted long chain alkenyl succinimide has a variety of
chemical structures and includes a mono-succinimide and/or a di-succinimide.
The long chain alkenyl group includes those with a number average molecular
weight of about 350 to about 10,000, in another embodiment about 400 to about
7000, in another embodiment about 500 to about 5000 and in yet another
embodiment about 500 to about 4000. In one embodiment the long chain
alkenyl group is a polyisobutylene group, which has a number average
molecular weight from 800 to 1600 and in another embodiment from about
1600 to about 3000. The succinimide includes those prepared by the
condensation of a hydrocarbyl-substituted acylating agent (e.g., hydrocarbyl-
substituted succinic anhydride) with a polyamine or an amino alcohol, a
polyalkylene polyamine or poly(ethyleneainine) such as triethylene tetramine,
tetraethylene pentamine, pentaethylene hexamine, still bottoms (often
described
as HPAXTM) or mixtures thereof. In one embodiment the polyamine is still
bottoms.
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The N-substituted long chain alkenyl succinimide dispersant additives
and their preparation are disclosed, for instance, in US Patent Numbers
3,361,673, 3,401,118 and 4,234,435.
Another class of dispersant includes Mannich bases, which are the
reaction products of alkyl phenols in which the alkyl group includes at least
about 30 carbon atoms with aldehydes (especially formaldehyde) and amines
(especially polyalkylene polyamines) and are described in more detail in U.S.
Patent 3,634,515.
Another class of ashless dispersant is high molecular weight esters.
These materials are similar to the above-described succinimides except that
they may be seen as having been prepared by reaction of a hydrocarbyl
acylating agent and a polyhydric aliphatic alcohol such as glycerol,
pentaerythritol, or sorbitol. Such materials are described in more detail in
U.S.
Patent 3,381,022.
The dispersant may also be post-treated by reaction with any of a variety
of agents. Among these are urea, thiourea, dimercaptothiadiazoles, carbon
disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted
succinic anhydrides, nitriles, epoxides, boron compounds, and phosphorus
compounds. References detailing such treatment are listed in U.S. Patent
4,654,403. In one embodiment the dispersant is borated dispersant especially a
borated N-substituted long chain alkenyl succinimide or mixtures thereof. In
one embodiment of the invention the borated dispersant is not present.
The dispersant is present in a ranges from about 0 wt % to about 25 wt
% of the composition, in another embodiment about 0.01 wt % to about 15 wt
% of the composition, in another embodiment about 0.1 wt % to about 8 wt %
of the composition and in yet another embodiment about 0.5 wt % to about 4 wt
% of the composition.
Detergent
The composition may further include a detergent. Detergent compounds
are known and include neutral or overbased, Newtonian or non-Newtonian,
basic salts of alkali, alkaline earth and transition metals with one or more
of a
phenate, a sulphurised phenate, a sulphonate, a carboxylic acid, a phosphorus
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acid, a mono- and/or a di- thiophosphoric acid, a saligenin, a salixarate, an
alkylsalicylate or mixtures thereof. Commonly used metals include sodium,
potassium, calcium, magnesium lithium or mixtures thereof. Most commonly
used metals include sodium, magnesium and calcium. In one embodiment of
the invention the detergent include a phenate, a sulphurised phenate or
mixtures
thereof. In one embodiment of the invention the detergent is a sulphurised
phenate.
Antioxidant
The composition of the invention may further include an antioxidant.
The antioxidant compounds are known and include a molybdenum
dithiocarbamate, a sulphurised olefin, a hindered phenol, a diphenylamine or
mixtures thereof. The antioxidant can be used alone or in combination. In one
embodiment the antioxidants includes a hindered phenol, a diphenylamine or
mixtures thereof.
The diphenylamine antioxidant includes those with a mono- or a di-
alkylated phenyl ring. Examples of suitable diphenylamine antioxidant include
bis-nonylated diphenylamine, nonyl diphenylamine, octyl diphenylamine, bis-
octylated diphenylamine, bis-decylated diphenylamine, decyl diphenylamine or
mixtures thereof.
The hindered phenol antioxidant includes a secondary butyl and/or a
tertiary butyl group as a sterically hindering group. The phenol group
optionally further includes a substituted hydrocarbyl group and/or a bridging
group linking to a second aromatic group. Examples of suitable hindered
phenol antioxidant include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-
butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-
butylphenol,
4-butyl-2, 6-di-tert-butylphenol 2, 6-di-tert-butylphenol, 4-pentyl-2, 6-di-
tert-
butylphenol, 4-hexyl-2, 6-di-tert-butylphenol, 4-heptyl-2, 6-di-tert-
butylphenol,
4-(2-ethylhexyl)-2,6-di-tert-butylphenol, 4-octyl-2,6-di-tert-butylphenol, 4-
nonyl-2,6-di-tert-butylphenol, 4-decyl-2,6-di-tert-butylphenol, 4-undecyl-2,6-
di-tert-butylphenol, 4-dodecyl-2,6-di-tert-butylphenol, 4-tridecyl-2,6-di-tert-
butylphenol, 4-tetradecyl-2,6-di-tert-butylphenol or mixtures thereof. In one
embodiment the hindered phenol antioxidant is an ester, for example,
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Irganox L-135 a commercially available product from Ciba Specialty
Chemicals.
Suitable examples of molybdenum dithiocarboamate include commercial
materials sold under the trade names such as Vanlube 822TM and MolyvanTM A
from R. T. Vanderbilt Co., Ltd., and Adeka Sakura-LubeTM S-100 and S-165
and S-600 from Asahi Denka Kogyo K. K.
The other performance additive compounds such as a metal deactivator
include a benzotriazole; a 1,2,4-triazole, a thiadiazole; a corrosion
inhibitor
include octylamine octanoate, condensation products of dodecenyl succinic
acid or anhydride and a fatty acid such as oleic acid with a polyamine; a foam
inhibitor include a copolymer of (a) ethyl acrylate; (b) 2-ethylhexylacrylate
and
(c) optionally vinyl acetate; a demulsifier include trialkyl phosphates,
polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene
oxide-propylene oxide) polymers; a pour point depressant include
polyacrylamides or polymers other than component (b) of the invention such as
esters of maleic anhydride-styrene, poly(meth)acrylates, polyacrylates; and a
seal swell agent include Exxon Necton-37TM (FN 1380) and Exxon Mineral
Seal Oil (FN 3200); may also be used in the composition of the invention.
The invention further provides a method comprising lubricating a
surface while imparting deposit control, the method employing a composition
comprising:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group;
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
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3) mixtures thereof, wherein the surface is a gear, a bearing or
mixtures thereof.
The surface is usually metallic and in one embodiment ferrous. In one
embodiment of the method, the wear preventing agent is present. Deposit
control includes sludge and other deposits. In one embodiment deposit control
is reduced sludge accumulation.
Process
The invention further provides a process for the preparation of a
conlposition comprising mixing:
(a) an oil of lubricating viscosity;
(b) an amine salt of a phosphorus compound; and
(c) a compound selected from the group consisting of:
1) a polymeric dispersant viscosity modifier wherein the polymeric
dispersant viscosity modifier excludes copolymers derived from
(a) a nitrogen containing monomer; and (b) methacrylic acid
esters containing from about 9 to about 25 carbon atoms in the
ester group; -
2) a polymeric dispersant viscosity modifier, a borated dispersant;
and a sulphurised olefin; and
3) mixtures thereof.
Components (a)-(c) are mixed sequentially and/or separately to form the
composition of the invention. The mixing conditions include a temperature in
the range from about 15 C to about 130 C, in another embodiment about 20 C
to about 120 C and in another embodiment about 25 C to about 110 C; and for
a period of time in the range about 30 seconds to about 48 hours, in another
embodiment about 2 minutes to about 24 hours, in another embodiment about 5
minutes to about 16 hours and in yet another embodiment about 10 minutes to
about 5 hours; and at pressures in the range about 86 kPa to about 266 kPa
(about 650 mm Hg to about 2000 mm Hg), in another embodiment about 91
kPa to about 200 kPa (about 690 mm Hg to about 1500 mm Hg), and in another
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embodiment about 95 kPa to about 133 kPa (about 715 mm Hg to about 1000
mm Hg).
The process optionally includes mixing other optional performance
additives as described above. In one embodiment the process provides a
process for the preparation of a concentrate. The optional performance
additives may be added sequentially, separately or as a concentrate.
Industrial Application
The composition of the present invention is useful for a gear or bearing
lubricant. The use of the composition described above is capable of imparting
one or more performance characteristics including deposit control, reduced
carbon varnish, decreased wear, low temperature viscometrics, high
temperature viscometrics or mixtures thereof. In one embodiment the
composition of the invention is capable of improving one or more of the
performance characteristics listed above.
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
Preparative Example 1: Polyrnethacrylate Dispersant Viscosity Modifier
(DVM)
A container is charged with about 120.1 parts methyl methacrylate,
about 722.4 parts C12-C15 alkylmethacrylate, about 6 parts n-dodecylmercaptan,
6 parts t-butylperoctoate (Akzo Trigonox-21) and about 242.0 parts of Total
85N oil, followed by stirring for about 0.25 hours. A reactor equipped with a
stirrer, thermocouple reaching into the charged reaction mixture, N2 inlet
atop
an addition funnel attached to a subsurface tube, and water condenser is
charged with about 1/3 of the monomer-initiator solution and about 15.4 parts
dimethylaminopropylmethacrylamide. The remainder of the monomer-initiator
mixture is placed in the addition funnel. With N2 addition at about 0.3 litres
per hour and stirring, the mixture is heated to about 110 C. over about 0.3
hour,
heating is stopped and an exotherm to about 143 C over about 0.1 hours is
observed. The temperature begins to drop and dropwise addition of the
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remaining solution is begun. Addition time is about 90 minutes; about 0.4
hours
after the peak exothermic temperature, the temperature is about 110 C. The
temperature during addition is maintained at about 110 C. The reaction is held
at about 110 C for one hour about 1.5 parts of t-butylperoctoate and about 3.5
parts of Total 85N oil is charged to the reaction, the reaction is held at
about
110 C for one hour. Another about 1.5 parts of t-butylperoctoate and about 3.5
parts of Tota185N oil is charged and the reaction is held at about 110 C for
two
hours. The resulting product has M, = 68,800 and polydispersity
(M, /Mõ)=1.90.
Preparative Example 2: Polymethacrylate (PMA) with no DVM Properties
Prepared in same process as Preparative Example of PMA DVM except
Dimethylaminopropylmethacrylamide is not added.
Preparative Example 3: Esterified Maleic Anhydride Styrene Interpolymer
DVM
A Polymeric Dispersant Viscosity Modifier derived from a maleic
anhydride-styrene interpolymer is prepared in a reactor charged with about
2498.7 parts of about 11.6% solids in toluene slurry of a maleic
anhydride/styrene (1:1 mole ratio) copolymer having a RSV=0.08, and about
500.3 parts Alfol 1218 (a mixture of predominantly straight chain primary
alcohols having from 12 to 18 carbon atoms). The materials are heated to about
120 C with N2 blowing while removing toluene. A mixture of about 15.8 parts
methane sulphonic acid and about 82.8 parts Alfol 810 (a mixture of
predominantly straight chain primary alcohols having from 8 to 10 carbon
atoms), is added over about 0.5 hour, heating is begun while removing water
and excess toluene, stabilising at about 135'C. The reaction is continued for
about 18 hours, removing water as toluene-water azeotrope. An aliquot has
total acid number =6.1 and strong acid number =3.7, net =2.4, about 98%
esterified. The temperature is raised to about 150'C. The strong acid is
neutralized with about 5.6 parts 50% aqueous NaOH added dropwise and held
for about 0.5 hour. Then about 3.0 parts aminopropylmorpholine are added
over about 0.2 hour followed by heating for 1 hour. An alkylated
diphenylamine is added (3.0 parts) and the materials are stripped to 1500C and
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at about 2.5 kPa (equivalent to about 20 mm Hg pressure). A light mineral oil
(SO-44) (218 parts) is added and after mixing, the oil solution is filtered to
yield 870 parts (80.0 % of theory) of product.
Preparative Example 4: Esterified Maleic Anhydride Styrene with no DVM
Properties
Prepared in same process as Preparative Example of esterified Maleic
anhydride Styrene DVM except aminopropylmorpholine is not added.
Examples 1-2 and Reference Examples 1-2
Example 1(Ex 1) was prepared by mixing in about 78.5 wt % of
EMERY 3008 PAO oil of lubricating viscosity about 14.5 wt % of a
dispersant polymethacrylate of Preparative Example 1 and about 6.4 wt % of a
mixture of a sulphurised isobutylene and an alkylamine salt of a phosphoric
acid (Primene 81R). Example 2 (Ex 2) is prepared the same way as, Example
1 except about 1.6 wt % of a, borated dispersant is added. Reference Examples
1 and 2 (Ref 1 and Ref 2) were prepared the same way as Example 1 and 2
respectively, except the dispersant polymethacrylate is replaced with a non-
dispersant polymethacrylate.
Examples 3-4 and Reference Examples 3-4
Examples 3 (Ex 3) and 4 (Ex 4) were prepared by the process of
' Examples 1 and 2. The only exception is the dispersant polymethacrylate is
replaced by 11 wt % of dispersant polyolefin (PA- 1160, commercially available
from DSM) and EMERY 3008 PAO oil of lubricating viscosity is present at
about 82 wt %. Reference Examples 3 (Ref 3) and 4 (Ref 4) were prepared by
the same process as Examples 3 and 4 except, the PA-1160 was replaced by
about 7.5 wt % of polyolefid(Lucant HC-2000 commercially available from
Mitsui Chemicals America, Inc.).
Examples 5-6 and Reference Examples 5-6
Examples 5 (Ex 5) and 6 (Ex 6) were prepared by were prepared by the
process of Examples 1 and 2. The only exception is the dispersant
polymethacrylate is replaced by about 22 wt % of a dispersant esterified
styrene-maleic anhydride interpolymer and the EMERY 3008 PAO oil of
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lubricating viscosity at about 71 wt %. Reference Examples 5 (Ref 5) and 6
(Ref 6) were prepared by the same process as Examples 5 and 6 except, the
dispersant esterified styrene-maleic anhydride interpolymer is replaced by a
non-dispersant esterified styrene-maleic anhydride interpolymer.
Test 1: Oxidation Stability Test
The Oxidation Stability test was carried out based on a modified
Coordinating European Council (CEC) test method CEC-L-48-A-00. The
modified test conditions used were a test tube is filled with about 90 g
sainple
0
and heated to about 160 C for a period of about 72 hours with an air flow of
about 83cc miri 1. The test procedure measures a tube rating, % viscosity
increase (at 40'C and 100*C) and spot rating. A lighter tube rating indicates
decreased deposit formation on the tube. Higher spot ratings indicate reduced
amounts of particulate matter being produced. The results obtained were:
Example Tube Rating Spot Rating
Ex 1 Medium 61.9
Ref 1 Heavy 49.4
Ex 2 Light to Medium 100
Ref 2 Heavy 26.4
Ex 3 Medium 43.7
Ref 3 Heavy 69.5
Ex 4 Light to Medium 100
Ref 4 Heavy 31.3
Ex 5 Heavy 30.3
Ref 5 Heavy 27.3
Ex 6 Medium 54.7
Ref 6 Medium 37.7
The analysis of the experimental data obtained for the following combinations
of reference examples and invention examples Ex 1 with Ref 1; Ex 2 with Ref
2; Ex 3 with Ref 3; Ex 4 with Ref 4; Ex 5 with Ref 5; and Ex 6 with Ref 6
shows that the composition of the invention produces decreased amounts of
deposit formation over the corresponding reference example.
In summary the composition of the invention is capable of imparting one
or more performance characteristics including deposit control, reduced carbon
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varnish, decreased wear, low temperature viscometrics, high temperature
viscometrics or mixtures thereof.
While the invention has been explained, it is to be understood that
various modifications thereof will become apparent to those skilled in the art
upon reading the specification. Therefore, it is to be understood that the
invention disclosed herein is intended to cover such modifications as fall
within
the scope of the appended claims.
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