Polymer compositions of improved compatibility in oil

A composition of an oil-soluble, olefin-based polymer and an oil-soluble polar polymer having nitrogen functionality, wherein the polymers in combination in oil exhibit incompatibility as evidenced by phase separation, shows improved compatibility by addition to the mixture of certain hydrocarbyl substituted hydroxyaromatic materials.

BACKGROUND OF THE INVENTION 
The present invention relates to a process and composition for improved 
mutual compatibility of olefin-based polymers and polar polymers having 
nitrogen functionality, in oil. 
A variety of polymeric and oligomeric additives are sometimes added to 
lubricating oil compositions and concentrates in order to improve the 
performance properties of the oil. One class of such compounds is 
olefin-based polymers, which are often used as viscosity modifiers. 
Another class of such compounds is polar, nitrogen-containing polymers, 
which likewise are often used as viscosity modifiers, and which further 
can be used to impart dispersant performance to an additive packages. 
Materials from each of these classes normally exhibit a reasonable degree 
of solubility in oil or in similar hydrocarbon solvents. That is to say, 
individually members of each class of compound can normally be dissolved 
in oil in a sufficient quantity to provide a concentrate for later 
dilution to prepare a fully formulated lubricant. 
However, it is often observed that these classes of additives cannot be 
satisfactorily used together, particularly in a concentrate. For reasons 
which are not fully understood, concentrates which contain both 
oil-soluble, olefin-based polymers and oil-soluble polar polymers having 
nitrogen functionality often undergo a physical or chemical interaction 
which leads to incompatibility between the species as evidenced by phase 
separation. Phase separation, as used in this application, is to be 
interpreted broadly and can be evidenced by the development of haziness 
upon mixing of two otherwise transparent solutions or by the failure of a 
mixture of polymers of the two types to form a clear solution when mixed 
in oil. In severe cases the phase separation can be evidenced by the gross 
physical separation of the mixture into two or more phases of liquids, 
solids, or semisolids. 
Such phase separation is almost always undesirable. Concentrates which 
exhibit severe phase separation may require stirring or heating in order 
to restore gross uniformity and to permit the concentrate to be 
effectively used. Even minor instances of phase separation are undesirable 
to the extent that they detract from the appearance and marketability of 
the concentrates. This incompatibility is most often a problem at 
temperatures of -18.degree. to +65.degree. C., which represents in many 
cases the range of temperatures at which concentrates of such additives 
are shipped or stored. The present invention provides a way to avoid such 
problems of incompatibility among otherwise oil-soluble polymeric 
additives. 
U.S. Pat. No. 4,594,378, Tipton, Jun. 10, 1986, discloses a mixture of an 
oil-soluble polymer which is a homopolymer of a non-aromatic monoolefin or 
a copolymer thereof with an aromatic monoolefin, a nitrogen-containing 
ester of a carboxyl-containing interpolymer, and a viscosity-reducing 
liquid organic diluent such as a naphthenic oil or an alkylated aromatic 
material. Examples of such oils include benzenes substituted with 
hydrocarbon-based groups of about 8 to about 30 carbon atoms. 
U.S. Pat. No. 4,546,137, Rossi et al., Oct. 8, 1985, discloses an additive 
combination for improving the cold flow properties of distillate fuels, 
comprising (a) an ethylene containing polymer, e.g. a copolymer of 
ethylene with vinyl acetate, (b) a hydrocarbon polymer, e.g. copolymers of 
ethylene and propylene or hydrocarbon polymers derivatised to contain 
polar groups (e.g. by grafting onto them maleic anhydride followed by 
amination), and (c) a polar oil soluble compound, which includes amides, 
salts, carboxylates, sulfonates, sulfates, phosphates, phenates, and 
borates, having hydrocarbon solubilizing groups; nitrogen compounds are 
particularly effective as component (c). 
SUMMARY OF THE INVENTION 
The present invention provides a composition comprising (a) at least one 
oil-soluble, olefin-based polymer; (b) at least one oil-soluble polar 
polymer having nitrogen functionality, wherein the polymers of (a) and (b) 
in combination in oil exhibit incompatibility as evidenced by phase 
separation; (c) at least one substituted hydroxyaromatic material, wherein 
the substitution comprises at least one hydrocarbyl group and contains in 
total at least about 24 carbon atoms; and (d) a nonpolar oleophilic 
medium. 
The invention also provides a process for improving the mutual 
oil-solubility of the polymers (a) and (b), comprising the step of 
combining with a mixture of (a) and (b) in a non-polar oleophilic medium, 
an amount of (c) at least one hydrocarbyl-substituted hydroxyaromatic 
material wherein the substitution comprises at least one hydrocarbyl group 
and contains in total at least about 24 carbon atoms, sufficient to reduce 
said incompatibility. 
DETAILED DESCRIPTION OF THE INVENTION 
The first component of the composition of the present invention is at least 
one oil-soluble, olefin-based polymer other than polar polymers containing 
nitrogen functionality, which are the subject of the second component, 
discussed in greater detail below. The olefin-based polymers are generally 
oleophilic materials which are nonpolar in the sense of being 
substantially free from polar functional groups such as hydroxy groups or 
amino groups. Of course, all materials other than the simplest symmetrical 
molecules exhibit some measurable degree of polarity, but the present 
polymers will fall into the generally understood category of non-polar 
polymers, normally having a dielectric constant of less than 3. 
These materials are oil-soluble, which means, as above, that they can 
normally be dissolved in oil in a sufficient quantity to provide a 
concentrate for later dilution to prepare a fully formulated lubricant. 
The level of solubility of one particular polymer may differ from that of 
another, depending on structure, molecular weight, and other factors, but 
in general the present polymers have a level of solubility of at least 1 
percent by weight, up to about 90 percent or more by weight, in mineral 
oil. 
The present polymers are further described as olefin based materials, which 
means that the bulk of the polymer comprises polymerized olefin monomers. 
Olefin monomers include .alpha.-olefins of 2 to 20 carbon atoms or more, 
preferably 2 to 12 or 2 to 8 carbon atoms, including ethylene, propylene, 
butene, pentene, hexene, octene, and isomers of such monomers. Olefin 
monomers also include olefins in which the double bond is not in an 
.alpha. position, but within a carbon chain or within a cyclic structure, 
although such monomers are often polymerized only with greater difficulty. 
Olefin monomers include alkenyl substituted aromatic monomers. Such 
aromatic comonomer may have a single aromatic ring (benzene ring) or it 
may have fused or multiple aromatic rings. Examples of fused or multiple 
aromatic ring materials include alkenyl substituted naphthalenes, 
acenaphthenes, anthracenes, phenanthrenes, pyrenes, tetracenes, 
benzanthracenes, biphenyls, and the like. The aromatic comonomer may also 
contain one or more heteroatoms in the aromatic ring, provided that the 
comonomer substantially retains its aromatic properties and does not 
contribute excessive polarity to the polymer. Such heteroaromatic 
materials include alkenyl-substituted thiophene. 
The nature of the alkenyl group of the alkenyl aromatic monomer is not 
particularly limited, provided that the alkenyl group provides an adequate 
means for incorporation of the alkenyl aromatic comonomer into the polymer 
chain. The alkenyl group is commonly a vinyl (CH.sub.2 .dbd.CH--) group; 
The most preferred alkenyl aromatic comonomer is styrene (vinyl benzene). 
While vinyl aromatic monomers can be formally classified as e-olefins, 
they are often considered to comprise their own class of monomers. 
The alkenyl aromatic comonomer can be substituted either on the aromatic 
ring or on the alkenyl side chain. The nature of the substitution is not 
particularly limited, provided that such substitution does not destroy the 
substantially non-polar character of the polymer formed therefrom; 
substitution, if present, is preferably by a hydrocarbyl group. 
Olefin monomers further include diene monomers. Dienes contain two double 
bonds, commonly located in conjugation in a 1,3 relationship. Olefins 
containing more than two double bonds, sometimes referred to as polyenes, 
are also considered to be included within the definition of "dienes" as 
used herein. Examples of such diene monomers include 1,3-butadiene and 
hydrocarbyl substituted butadienes such as isoprene and 
2,3-dimethylbutadiene. Non-conjugated dienes such as norbornadiene are 
also available. These and numerous other monomers are well known and 
widely used as components of elastomers as well as modifying monomers for 
other polymers. 
The olefin-based polymer can be an .alpha.-olefin polymer or copolymer. 
These materials include polyethylene, ethylene/.alpha.-olefin copolymers 
such as ethylene/propylene copolymers, ethylene/butylene copolymers, 
ethylene/hexene copolymers, and ethylene/octene copolymers, grades of 
polyethylene containing relatively more polar comonomers such as vinyl 
acetate (in sufficiently small amounts to not significantly change the 
nonpolar nature of the polymer), polypropylene and propylene copolymers, 
and polybutylene and butylene copolymers. Such materials can be considered 
plastics or elastomers depending on the proportions of the various 
comonomers present. The preparation of such .alpha.-olefin polymers is 
well known and includes such processes as free radial polymerization and 
polymerization by coordination catalysis. 
Such olefin polymers include not only direct copolymers, but also graft 
copolymers, that is, olefin polymers onto which minor amounts of polar 
vinyl monomers have been grafted. Such graft comonomers are sometimes used 
to impart dispersancy to the polymer. As long as the amount of comonomer, 
whether grafted or directly copolymerized, remains reasonably low, the 
polymer as a whole can be considered non-polar and may still exhibit 
incompatibility with the polar polymer (b). 
Another class of olefin based polymers is vinyl aromatic/.alpha.-olefin 
copolymers, including ethylene/styrene copolymers. 
The olefin based polymer can also be a diene-containing polymer. 
Polybutadiene, polyisoprene, and the like, are well-known elastomers. 
Other diene-containing polymers include ethylene-propylene-diene polymers 
(where the diene can be, for instance, butadiene, isoprene, or other of 
the dienes described above) and vinyl aromatic/diene copolymers. Along the 
commonest of the latter copolymers are styrene/butadiene polymers, which 
can be random, block, or random block copolymers. Random copolymers are 
those in which the comonomers are randomly or nearly randomly arranged in 
the polymer chain; block copolymers are those in which one or more 
relatively long chains of one type of monomer are joined to one or more 
relatively long chains of another type; and random block copolymers are 
those in which relatively shorter chains of one type monomer alternate 
with similar chains of another type. Although the present invention can be 
employed satisfactorily with random, block, or random block 
styrene/butadiene polymers, it is more advantageously used with block 
copolymers, preferably di- or triblock polymers. That is, those polymers 
having relatively larger hydrocarbon segments (as opposed to the short 
chains characteristic of random block polymers) are more readily 
compatibilized by the present invention. Another type of suitable polymer 
is radial or "star" polymers. In all of the polymers discussed, third and 
higher comonomers can also be present, provided that the essential nature 
of the olefin-based polymer is not changed. 
Olefin-based polymers which contain diene monomers generally retain a 
certain amount of unsaturation, since normally only one of the double 
bonds of the diene monomer will participate in the polymerization 
reaction. Often the residual unsaturation is removed by hydrogenating the 
polymer by known methods. The result is a partially or fully hydrogenated 
diene copolymer, examples of which include hydrogenated 
ethylene/propylene/diene polymers, hydrogenated styrene/diene block 
copolymers, hydrogenated styrene-diene random block copolymers, and 
hydrogenated styrene-diene copolymers (or random copolymers). Hydrogenated 
diene polymers generally exhibit somewhat better chemical stability than 
their non-hydrogenated counterparts. 
The oil-soluble, olefin-based polymer component of the present compositions 
can be a single polymeric species or it can be a mixture of species. When 
a single species is present, it will preferably be a relatively low 
molecular weight polymer, having a weight average molecular weight below 
10,000, preferably 600 to 5000 and more preferably 2000 to 5000. Such low 
molecular weight materials tend to exhibit better solubility in oils and 
are more readily made compatible with the oil-soluble polar polymers 
described below. One or more of these low molecular weight polymer may be 
present in the composition. 
In one aspect of this invention there is present, in addition to the lower 
molecular weight olefin-based polymer, a higher molecular weight 
olefin-based polymer, having a weight average molecular weight greater 
than 50,000, for instance 100,000 to 250,000. The higher molecular weight 
polymer can be any of the aforementioned types, but is preferably a type 
similar to that of the particular lower molecular weight material. For 
example, a higher molecular weight styrene-diene block copolymer can be 
present in combination with a lower molecular weight styrene-diene block 
copolymer, or a high molecular weight EPDM (ethylene propylene diene) 
polymer can be present in combination with a low molecular weight 
polyisobutylene. Such mixtures of different molecular weight polymers are 
sometimes desirable to provide enhanced thickening performance and 
improved low temperature viscosity, while maintaining acceptable shear 
stability. If such a high molecular weight olefin polymer is present, it 
is preferably used in combination with a lower molecular weight polymer as 
described above. This is because many such high molecular weight polymers, 
alone, are relatively difficult to compatibilize in concentrates 
containing the oil-soluble polar polymers, and thus the benefits of the 
present invention may not be completely realized. The lower molecular 
weight polymer is thought in those instances to serve as an aid or 
co-agent for the higher molecular weight polymer. Thus a system containing 
(a) a low molecular weight oil-soluble olefin-based polymer along with 
(a') a high molecular weight polymer, (b) an oil-soluble polar polymer 
having nitrogen functionality, (c) a selected hydroxyaromatic material, 
and (d) an oil, can exhibit good compatibility where a mixture of (a'), 
(b), (c), and (d) may not. 
If both low and high molecular weight olefin polymers are present, they 
should be present in such amounts that the low molecular weight material 
imparts improved compatibility with the high molecular weight material. 
This is a ratio which can be readily determined in each instance; but in 
general the ratios of low to high molecular weight material will be 10:1 
to 500:1, preferably 50:1 to 200:1. 
The second major component of the composition of the present invention (b) 
is at least one oil-soluble polar polymer having nitrogen functionality. 
These materials are first oil-soluble, which means, as above, that they 
can normally be dissolved in oil in a sufficient quantity to provide a 
concentrate for later dilution to prepare a fully formulated lubricant. 
The level of solubility of one particular polymer may differ from that of 
another, depending on structure, molecular weight, and other factors, but 
in general the present polymers have a level of solubility of at least 1 
percent by weight, up to about 90 percent or more by weight, in mineral 
oil. 
These polymers are designated as polar, by which is meant that they contain 
substantial amounts of polar functional groups such as heteroatoms which 
impart overall polar character to the polymer. Examples of functional 
groups which can impart polar character to a polymer include hydroxy, 
amino, keto, acid, ester, amide, imide, thio, mercapto, and phosphorus 
based groups. The polar functional groups will not be present in such 
large amounts, however, as to destroy the oil-solubility of the polymer. 
Suitable polymers commonly have dielectric constants of about 3 or 
greater. 
Finally, this class of polymer is described as possessing nitrogen 
functionality, and preferably basic nitrogen functionality. While the 
presence of nitrogen functionality may impart a measure of polar character 
to the polymer, the characteristic of nitrogen functionality is considered 
for purposes of the present invention to be a separate attribute from that 
of polarity, discussed above. Suitable groups which impart nitrogen 
functionality include primary, secondary, and tertiary amine groups, amide 
groups, imide groups, cyano groups, quaternary ammonium groups, imidic 
acid groups, nitro groups, hydrazyl, azo, and diazo groups, pyridyl 
groups, pyrimidyl groups, pyrrole groups, and isomeric structures thereof. 
The preferred nitrogen functionality is the basic nitrogen functionality 
which is imparted by one or more amine groups. The amine groups can be 
present in the polymer as a part of the chain, as in the case of a 
poly(alkyleneamine), or they can be present as pendant groups from the 
main carbon chain. Finally, they can be present in the polymer by virtue 
of reaction with a reactive site on the polymer, such as an acid or 
anhydride group, or equivalent, as described in more detail below. The 
amines can be polyamines, that is, amino compounds containing more than 
one nitrogen atom. Polyamines may be aliphatic, cycloaliphatic, 
heterocyclic or aromatic. Examples of the polyamines include alkylene 
polyamines, hydroxy containing polyamines, arylpolyamines, and 
heterocyclic polyamines. Alkylene polyamines are represented by the 
formula 
##STR1## 
wherein n preferably has an average value from 1 or 2 to 10 or 7 or to 5, 
and the "Alkylene" group preferably has from 1 or 2 to 10 or 6 or 4 carbon 
atoms. Each R is independently hydrogen, or an aliphatic or 
hydroxy-substituted aliphatic group of up to about 30 carbon atoms. Such 
alkylenepolyamines include methylenepolyamines, ethylenepolyamines, 
butylenepolyamines, propylenepolyamines, pentylenepolyamines, etc. 
Ethylenepolyamine, also referred to as polyethyleneamine, is a preferred 
material. Such polyamines can be prepared by the reaction of ethylene 
dichloride with ammonia or by reaction of an ethylene imine with a ring 
opening reagent such as water, ammonia, etc. Suitable amines for such 
reaction also include N,N-dihydrocarbylalkanediamines and N-aminoalkyl 
nitrogen heterocycles. Specific amines of these types include 
N,N-dimethyl-1,3-propanediamine and N-(3-aminopropyl)morpholine (prepared 
by hydrogenation of the cyanoethylation product of morpholine and 
acrylonitrile, using a nickel catalyst). 
Polymers which can react with amines to form nitrogen-containing polymers 
can generally be classified as polymers with (A) acidic or (B) neutral 
reactive comonomer functionality. By acidic functionality (A) is generally 
meant functionality derived from acids, such as carboxylic acids, 
including (as is customary) their anhydrides. Examples of acids which can 
serve as comonomers to impart acidic function are maleic, itaconic, 
citraconic, and fumaric acids or anhydrides (as applicable), alkyl 
hydrogen maleates, itaconates, citraconates, and fumarates, maleamidic and 
fumaramidic acids, acrylic and methacrylic acids, cinnamic acid, and 
crotonic acid. By neutral functionality (B) is generally meant esters, 
amides, and other non-acidic functionality which is nevertheless reactive 
with amines. Examples of comonomers which supply suitable neutral 
functionality include dialkyl maleates, fumarates, itaconates, and 
citraconates, alkyl acrylates and methacrylates, alkyl cinnamates, alkyl 
crotonates, and corresponding amides. If neutral functionality is used, 
preferably at least one ester group will be present in the polymer. Acid 
functionality in a polymer can react with amines to incorporate nitrogen 
functionality by direct amide formation with liberation of water (unless 
an anhydride is used). Neutral functionality in a polymer can react by 
e.g. amide-ester interchange, with liberation of the alcohol from the 
ester. For most effective incorporation of nitrogen functionality by this 
route, the polymer should not contain any appreciable amount of 
copolymerized vinyl esters: amide-ester interchange with vinyl esters 
would liberate a monomeric amide, leaving only a hydroxy group on the 
polymer chain. 
An example of a class of polymers with acid or anhydride functionality 
suitable for reaction with the above amines is maleic anhydride-olefin 
copolymers and their equivalents. The anhydride can be in the form of 
acid, acyl chloride, ester, or other reactive moiety. Maleic acid 
(cis-butenedioic acid), its esters, or its anhydride can be incorporated 
into a polymer by direct copolymerization or by grafting onto a pre-formed 
polymer substrate. When polymerized or grafted, the ethylenic double bond 
of maleic acid is reduced to a single bond, so that the resulting monomer 
could also be described as a succinic acid derivative. Fumaric acid, the 
trans isomer of butenedioic acid, and its esters, are indistinguishable 
from maleic acid or its esters when incorporated into a polymer. Other 
useful derivatives of maleic acid include those with substitution of one 
or more hydrogen atoms on one or both of the ethylenic carbon atoms by 
alkyl groups; this type of derivative includes citraconic acid, which has 
one methyl substituent. A related material is itaconic acid, 
2-methylenesuccinic acid. A preferred acid is maleic acid, or its 
anhydride. 
The olefin comonomer which, together with maleic anhydride comonomer, forms 
a suitable polymer for reaction with amines can be any copolymerizable 
olefin comonomer. It is preferably an alkenyl substituted aromatic 
monomer, as has been defined above. The most preferred alkenyl substituted 
aromatic monomers are styrene and alkylated styrenes; the most preferred 
polymers are copolymers of these styrenes with maleic anhydride. 
The molar ratio of the alkenyl substituted aromatic monomer to the maleic 
anhydride monomer or derivative thereof in the copolymer is normally about 
5:1 to about 1:1.5. Preferably the copolymer contains these two comonomers 
in a ratio of about 1:1, particularly preferably in the substantial 
absence of third comonomer. This 1:1 mole ratio is preferred in part 
because maleic anhydride and styrene comonomers under certain reaction 
conditions copolymerize in about this ratio in a regularly alternating 
fashion. This regularly alternating 1:1 copolymer of maleic anhydride and 
styrene is a preferred copolymer for the present invention. 
The regularly alternating 1:1 copolymer of maleic anhydride and styrene can 
be prepared by polymerizing equimolar amounts of maleic anhydride and 
styrene with stirring in a toluene medium under nitrogen. A free radical 
initiator is used; if benzoyl peroxide is selected, the polymerization 
reaction is run at 100.degree. C. over a course of several hours. 
While normally the polymeric material as just described will be a binary 
copolymer of maleic anhydride or a derivative thereof with an 
alkenyl-substituted aromatic comonomer, it is possible that one or more 
additional comonomers may be present. One class of such comonomers 
comprises those comonomers which impart branching or crosslinking to the 
polymer chain. Examples of comonomers suitable for this purpose include 
those comonomers which may themselves be alkenyl substituted aromatic 
materials, in particular, dialkenyl substituted aromatic materials such as 
divinylbenzene. These materials are normally less preferred, however, in 
as much as extensive branching or crosslinking can lead to gelation in 
solution, even at low levels of incorporation. 
Still other comonomers may be introduced into these copolymers for various 
purposes, e.g. to modify the solubility, processing, chemical, or 
rheological properties of the polymer. Examples of such comonomers include 
acrylic acid, methacrylic acid, and alkyl acrylates and methacrylates. The 
most preferred third comonomers are alkyl acrylates and methacrylates and 
salts thereof. The amount of such third comonomer (which term includes 
fourth and higher comonomers), if any, is normally 0 to 20 mole percent of 
the copolymer, preferably 0 to 5 mole percent. 
Amide-forming reactions, whether by direct reaction of an amine with an 
acid or anhydride, or by amide-ester interchange, are well known reactions 
within the ability of one of ordinary skill in the art. Such reactions are 
generally conducted by mixing the materials at elevated temperature, e.g. 
140.degree.-180.degree. C., either in solution or in a melt, optionally in 
the presence of an acidic catalyst, with removal of the byproduct water or 
alcohol. 
Nitrogen-containing polymer can also be prepared by polymerizing monomers 
with nitrogen functionality directly into a polymer chain, using known 
polymerization process such as free-radical polymerization. Suitable 
nitrogen-containing monomers include dialkylaminoethyl acrylates or 
methacrylates, dialkylaminoethyl acrylamides or methacrylamides, 
dialkylaminopropyl acrylamides or methacrylamides, 
dialkylamine-poly(oxyalkyl) acrylates or methacrylates, 2-vinylpyridine, 
4-vinylpyridine, N-vinylpyrrolidone, N-vinylcarbazol, and 
1-vinylimidazole. These monomers can also be present in a polymer which is 
to be further reacted with an amine as outlined above. 
The third major component (c) of the composition of the present invention 
is at least one substituted hydroxy-aromatic material, wherein the 
substitution comprises at least one hydrocarbyl group and contains in 
total at least 24 carbon atoms. Hydroxy aromatic materials include phenols 
as well as naphthols and other hydroxy-substituted polynuclear aromatic 
hydrocarbons, including fused and bridged ring systems. The preferable 
materials are phenols. The phenols can have other substituent groups such 
as amino groups, additional hydroxy groups, nitro, halo, hydroxyalkyl, 
acyloxy, acyl, alkoxyalkyl, alkoxy, amido, and carboxamide groups. 
However, the hydroxy aromatic material should have at least one 
hydrocarbyl group. In order to provide optimum compatibilization 
properties, the hydrocarbyl group or groups should contain at least 24 
carbon atoms in total. These carbon atoms can be located entirely in a 
single hydrocarbyl group of 24 or more carbon atoms, or they may be 
distributed over two or more hydrocarbyl groups. For instance, one 
hydrocarbyl group could have 18 carbon atoms and a second could have 6 or 
more carbon atoms. Preferably the hydrocarbyl groups contain a total of at 
least 30 carbon atoms. Preferably one hydrocarbyl group contains at least 
24 and more preferably at least 30 or even at least 31 or 36 carbon atoms, 
or, as otherwise expressed, having a lower molecular weight of at least 
340, preferably at least 400, and more preferably at least 430 or 500. It 
is further preferred that the hydrocarbyl group be an alkyl group, and 
further that it have a number average molecular weight of 400 to 2000 
(which corresponds to 28-143 carbon atoms). Such materials will normally 
include molecules having alkyl groups of a variety of chain lengths; hence 
a number average molecular weight is normally used to describe them. 
Certain preferred materials include polybutenylphenols, and especially 
those in which the polybutenyl group has a number average molecular weight 
of 500 to 800 (which corresponds to 36 to 57 carbon atoms or 9 to 14 
butene units). 
Such hydrocarbyl substituted hydroxy aromatic materials are prepared by 
known techniques. The attachment of a hydrocarbyl group to the aromatic 
moiety can be accomplished, for instance, by the Friedel-Crafts reaction, 
wherein an olefin (e.g. a polymer containing an olefinic bond), or a 
halogenated or hydrohalogenated analog thereof, is reacted with a phenol 
in the presence of a Lewis acid catalyst. Methods and conditions for 
carrying out such reactions are well known to those skilled in the art and 
are discussed, for example, in the article entitled "Alkylation of 
Phenols" in "Kirk-Othmer Encyclopedia of Chemical Technology," Third 
Edition, Vol. 2, pages 65-66, Interscience publishers, a division of John 
Wiley and Company, New York. In an exemplary process, an alkylated phenol 
is prepared by reacting phenol with polybutene having a number average 
molecular weight of about 1,000 in the presence of a boron 
trifluoride/phenol catalyst. The catalyst is neutralized and removed by 
filtration. Stripping of the product filtrate at reduced pressure provides 
purified alkylated phenol as a residue. 
The amount of the hydroxy aromatic material is that amount which is 
sufficient to provide improved compatibility between components (a), the 
olefin based polymer or polymers, and (b), the polar polymer having 
nitrogen functionality. Compatibility can be defined as the absence of 
phase separation, as described above; improved compatibility refers to 
reduction in the severity of phase separation or complete elimination of 
phase separation, as will be apparent upon observation by the person 
skilled in the art. Preferably the amount of component (c), the 
hydroxyaromatic material, will be 10 to 100% by weight of the total of 
components (a) (including (a') if any) and (b), and more preferably it 
will be 25 to 50% by weight of that total. 
The relative amount of components (a) and (b) and their concentrations in 
oil are those amounts at which there is evidence of incompatibility under 
conditions of actual use, for example, extended storage or shipment at 
some temperature in the range of -18.degree. to +65.degree. C. Most often 
components (a) and (b) will be present in a weight ratio (a):(b) of 15:1 
to 1:1, and particularly a weight ratio of 10:1 to 1.5:1. 
The present invention is most useful when components (a) and (b) are 
present in relatively high concentrations, as in a concentrate. 
Concentrates are solutions or dispersions of materials in an oil or in 
another medium which is compatible with the end use of the substance. They 
are widely used to aid in handling of solids or otherwise difficult 
materials and are designed to be added to e.g. lubricating oil to form a 
final lubricant composition. Normally for the present invention the medium 
of the concentrate (d) is itself an oil of lubricating viscosity as 
defined below, and it is preferably a mineral oil. The invention can also 
be effective when used with another nonpolar oleophilic medium such as a 
hydrocarbon solvent. 
Suitable oils of component (d) of the present invention include natural or 
synthetic lubricating oils and mixtures thereof in which components (a) 
and (b) of the present invention exhibit mutual incompatibility which is 
alleviated by the present invention. Suitable oils are generally 
hydrocarbon oils of low polarity, such as mineral oils of paraffinic, 
naphthenic, or mixed types; solvent or acid treated mineral oils; and oils 
derived from coal or shale. Certain vegetable oils, which have higher 
polarity, are unsuitable. Synthetic lubricating oils based on esters would 
normally be expected to be too polar to fully exhibit the advantages of 
the present invention, while others, of lower polarity, may be suitable. 
Other synthetic lubricating oils of lower polarity would be suitable; such 
materials include synthetic hydrocarbon oils and alkyl aromatic oils. 
Other materials, including halogen-substituted hydrocarbon oils, alkylene 
oxide polymers (including those made by polymerization or copolymerization 
of C.sub.2 to C.sub.18 alkylene oxides such as ethylene oxide or propylene 
oxide), can also be suitable, although they may be less frequently 
employed in commercial practice. Silicon-based oils (including siloxane 
oils and silicate oils) are generally unsuitable. Included among the 
suitable oils are unrefined, refined, and rerefined oils. In general 
suitable oils will have a dielectric constant of less than about 3. 
Mineral oil is especially preferred. 
Other materials of suitable low polarity for use as the nonpolar oleophilic 
medium include hydrocarbon solvents, in particular aliphatic hydrocarbons 
such as hexane, cyclohexane, octanes, and the like. Such materials, 
however, may be less preferred for commercial use because of their 
volatility. 
The amount of oil or other oleophilic medium in the composition is normally 
10 to 50 weight percent of the total composition, preferably 15 to 40 
weight percent, and most preferably 20 to 30 weight percent. However, 
larger amounts can still be effectively used, particularly if one or more 
of the components exhibits more limited solubility in the medium. 
Effective amounts correspond generally to concentrations found when oil is 
used as a component in a concentrate. 
The compositions of the present invention can include one or more further 
optional components which are commonly used in lubricants, including 
antioxidants, corrosion inhibitors, and pour point depressants. Such 
additives can be conveniently made a part of a concentrate of the present 
invention in order to provide for their facile incorporation into a fully 
formulated lubricant. The lubricant can then benefit from the presence of 
the additives for their antioxidant, corrosion inhibition, pour point 
depression, or other pertinent properties. 
The exact degree of improvement in compatibility in compositions of the 
present invention will depend on a variety of factors. The relative 
amounts and chemical identities of the species will be important. In 
addition, the mixing or storage conditions can also play a role. 
Substances in general tend to be more compatible at higher temperatures, 
for example. Molecular weight and degree of branching of the polymers may 
also play a role. It is also believed that the presence of third bodies, 
such as metal surfaces of steel storage containers, can lead to reduced 
compatibility or phase separation. But under a variety of such conditions 
the presence of the hydrocarbyl-substituted hydroxyaromatic material will 
provide improved compatibility compared to a corresponding composition 
without that additive. 
As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" 
is used in its ordinary sense, which is well-known to those skilled in the 
art. Specifically, it refers to a group having a carbon atom directly 
attached to the remainder of the molecule and having predominantly 
hydrocarbon character. Such groups include hydrocarbon groups, substituted 
hydrocarbon groups, and hetero groups, that is, groups which, while 
primarily hydrocarbon in character, contain atoms other than carbon 
present in a chain or ring otherwise composed of carbon atoms.

EXAMPLES 
Example 1 (comparative). A mixture is prepared of (a) 75 parts by weight 
polyisobutene, 1700 number average molecular weight, and (b) 25 parts by 
weight of a composition of a 1:1 alternating maleic anhydride/styrene 
copolymer, 100,000 weight average molecular weight, 100 parts of which are 
esterified with a mixture of 109 parts of 12-18 carbon atom length primary 
alcohols, 73 parts of 8-10 carbon atom length primary alcohols, and 7.4 
parts of n-butyl alcohol, to about 95% conversion, followed by 
neutralization and reaction with 7.2 parts of 4-(3-amino-propyl)morpholine 
to give a nitrogen content of 0.44 percent by weight (oil free basis). The 
component (b) contains about 45% polymeric material (i.e. accounting for 
about 11.25 parts by weight) and about 55% hydro-treated 100 neutral 
diluent oil (i.e. about 13.75 parts by weight). The mixture is prepared by 
adding the polyisobutylene followed by the nitrogen-containing maleic 
anhydridestyrene ester polymer to a blending container, gradually heating 
the materials to 80.degree. C. under constant mechanical stirring, holding 
at 80.degree. C. until the system is homogeneous. The mixture initially 
has a hazy appearance; upon standing for one to two days, the mixture 
separates into two distinct layers. 
Example 2 (comparative). Components (a) and (b), as in Example 1, are 
combined in equal amounts, component (b) containing, as in Example 1, 55% 
oil. The mixture separates upon standing for two days, as in Example 1. 
Example 3.A mixture is prepared of 30 parts by weight component (a) and 50 
parts component (b), as in Example 1, along with (c) an additional 20 
parts by weight of polyisobutylene (940 number average molecular weight) 
substituted phenol (95-100% chemical, balance residual polyisobutylene). 
The resulting mixture is amber, slightly hazy and slightly grainy. No 
change in appearance is detected after allowing the mixture to stand for 2 
weeks at room temperature. 
Example 4. Example 3 is repeated, using 70 parts of component (a), 20 parts 
of component (b), and 10 parts of component (c). The resulting mixture is 
amber, hazy and slightly grainy. No change in appearance is detected after 
allowing the mixture to stand for 2 weeks at room temperature. 
Example 5. Example 3 is repeated, using 65 parts of component (a), 15 parts 
of component (b), and 20 parts of component (c). The resulting mixture is 
amber with a trace of haze and a smooth appearance. No change in 
appearance is detected after allowing the mixture to stand for 2 weeks at 
room temperature. 
Example 6. (comparative) A mixture is prepared as in Example 1, of (a) 90 
parts by weight polyisobutylene, 1700 number average molecular weight, 
containing 90 percent polymer and 10 percent diluent oil, (b) 22 parts by 
weight of a composition of a 1:1 alternating maleic anhydride/styrene 
copolymer, 150,000 weight average molecular weight, 100 parts of which are 
esterified with a mixture of 138 parts of 12-18 carbon primary alcohols 
and 26.6 parts of n-butyl alcohol to 95% conversion, followed by 
neutralization or reaction with 7.5 parts of 4-(3-aminopropyl)morpholine 
to give a nitrogen content of 0.4% by weight (oil-free basis). Component 
(b) contains 35 percent polymeric material (accounting for 7.7 parts by 
weight) and 65 percent hydrotreated 100 neutral diluent oil. The mixture 
also contains 4 parts of an additive package of 55% polymethacrylic ester 
pour point depressant and 45% oil. The resulting mixture is hazy and 
granular in appearance. When the composition is diluted by mixing it with 
an equal weight of 100 Neutral base oil from Exxon, the mixture is hazy. 
Example 7. Example 6 is repeated except that in addition, 20 parts by 
weight of the polyisobutylene substituted phenol (c) of Example 3 is 
included. The resulting mixture is clear, having only a trace of granular 
appearance, with no further change in appearance upon standing for 2 weeks 
at room temperature. When the composition is diluted as in Example 6, the 
resulting mixture is clear. 
Example 8. Example 7 is repeated except that the amount of component (a) is 
reduced to 70 parts by weight. The resulting mixture is clear, with a 
smooth appearance (no change after 2 weeks), and leads to a clear mixture 
upon dilution as in Example 6. 
Example 9. Example 8 is repeated except that the amount of component (b) is 
increased to 30 parts by weight. The resulting mixture is clear, with a 
smooth appearance (no change after 2 weeks), and leads to a clear mixture 
upon dilution as in Example 6. 
Example 10. Example 8 is repeated, except that in addition 5 parts by 
weight of a high molecular weight (200,000 weight average) hydrocarbon 
(EPDM) polymer solution is added. The added solution is 10% polymer in 90% 
100 neutral diluent oil. The concentrate formed is clear, with a smooth 
appearance, and leads to a clear mixture upon dilution as in Example 6. 
Example 11-15. Example 7 is repeated except that in addition 15 parts by 
weight of a high molecular weight polymer solution (in 100 neutral diluent 
oil) is added. The identity of each added polymer and the results are 
shown below: 
Ex. 11: The polymer of Example 10; the concentrate formed is clear, with a 
smooth appearance, and leads to a clear mixture upon dilution as in 
Example 6. 
Ex. 12: A hydrogenated random block copolymer of styrene and butadiene, 
weight average molecular weight 220,000, about 8% polymer solution; the 
concentrate formed is very hazy and granular in appearance. 
Ex. 13: A hydrogenated diblock copolymer of styrene and isoprene, weight 
average molecular weight 200,000, about 6% polymer solution; the 
concentrate formed is clear, with a smooth appearance, and leads to a 
clear mixture upon dilution as in Example 6. 
Ex. 14: A hydrogenated random block copolymer of styrene and butadiene, 
weight average molecular weight 130,000, about 8% polymer solution; the 
concentrate formed is hazy. 
Ex. 15: A hydrogenated diblock polymer of styrene and isoprene, weight 
average molecular weight 140,000, about 10% polymer solution; the 
concentrate formed has a very slight haze, with a smooth appearance, and 
leads to a clear mixture upon dilution as in Example 6. 
Examples 16-29. The following examples were prepared by blending 16.1 parts 
by weight of a polyisobutylene (940 number average molecular weight) 
substituted phenol, which contains 10% diluent oil, with an amount, 
indicated in parts by weight in Table 1 below, of an esterified 
alternating maleic anhydride styrene copolymer. (This is, as indicated in 
Table 1, the ester copolymer defined in Example 6, the ester copolymer 
defined in Example 1, or one similar to that in Example 1, except that it 
is esterified with 139 parts of the C.sub.12 -C.sub.18 alcohols, 25 parts 
of the C.sub.8 -C.sub.10 alcohols, and 14.8 parts of n-butyl alcohol.) The 
ingredients are mixed for 60.degree.-70.degree. C. for 1 hour. Thereafter 
0.8 parts of a first polymethacrylate ester pour point depressant 
("Acryloid.TM. 150," comprising 40% chemical and 60% diluent oil) and 2.0 
parts of a second polymethacrylate ester pour point depressant 
("Acryloid.TM. 156," comprising 60% chemical and 40% diluent oil) are 
blended in. The mixture is stirred at 60.degree.-70.degree. C. until it is 
homogeneous. Finally, an amount (indicated in Table 1) of polyisobutylene, 
1700 number average molecular weight, containing 10% diluent oil, is 
added. The entire mixture is stirred at 60.degree.-70.degree. C. for 1 
hour. Thereafter portions of each mixture are stored in the presence of 
steel for four weeks at room temperature and, in a separate, more severe 
test at 65.degree. C., and then observed for separation of components. In 
Table 1 the results at 4 weeks and at 26 weeks are noted: "C" indicates 
the mixture remains compatible; "S" indicates that the mixture shows signs 
of separation. Results are reported for both temperatures. 
TABLE 1 
______________________________________ 
Ester Ester Ester 
Polyiso- of sim. of Results (RT/65.degree.) 
Ex. butylene Ex. 6 to Ex. 1 
Ex. 1 4 weeks 
26 weeks 
______________________________________ 
16 56.50 -- 24.60 -- C/C C/C 
17 50.35 -- 30.75 -- C/S.sup.a 
C/C 
18 62.65 -- 18.45 -- C/C.sup.b 
C/C 
19 44.20 -- 36.90 -- C/C C/C 
20 68.80 -- 12.30 -- C/C C/C 
21 56.50 24.60 -- -- C/S C/nd 
22 50.35 30.75 -- -- C/S C/nd 
23 62.65 18.45 -- -- C/S C/nd 
24 44.20 36.90 -- -- C/S C/nd 
25 68.80 12.30 -- -- C/C C/C 
26 32.9 49.0 -- -- C/C C/C 
27 32.9 -- -- 49.0 C/S S/S 
28 44.3 36.8 -- -- C/S C/S 
29 44.3 -- -- 36.8 S/S S/S 
______________________________________ 
.sup.a Questionable observation. 
.sup.b Some sediment observed, perhaps due to contamination. 
nd - not determined 
Examples 30-41. The procedure of Example 15-29 is substantially repeated, 
except that in place of the two polymethacrylate pour point depressants 
used, 3 parts by weight of a single material which may function as a pour 
point depressant in the concentrate is present. This material is either 
the Acryloid.TM. 150, referred to above (designated as "A" in Table 2), a 
polymethacrylate ester/decene oligomer synthetic oil ("RohmTech 
Viscobase".TM., designated as "B" in Table 2) or another polymethacrylate 
pour point depressant ("Viscoplex.TM. 1-330"), 50% chemical and 50% 
diluent oil (designated as "C" in Table 2). The results are as indicated: 
TABLE 2 
______________________________________ 
Ester Ester 
Polyiso- of sim. other Results (RT/65.degree.) 
Ex. butylene Ex. 6 to Ex. 1 
mat'l 4 weeks 
26 weeks 
______________________________________ 
30 56.30 24.60 -- A C/C C/C 
31 56.30 24.60 -- B C/S C/S 
32 56.30 24.60 -- C C/S C/S 
33 50.15 30.75 -- A C/C C/C 
34 50.15 30.75 -- B C/S C/S 
35 50.15 30.75 -- C C/S C/S 
36 62.45 18.45 -- A C/C C/C 
37 62.45 18.45 -- B C/S C/S 
38 62.45 18.45 -- C C/S C/S 
39 56.30 -- 24.60 A C/S S/S 
40 56.30 -- 24.60 B C.sup.b /S 
S/S 
41 56.30 -- 24.60 C C/S S/S 
______________________________________ 
.sup.b Sample became hazy. 
Examples 42-50. The procedure of Examples 30-41 is substantially repeated 
except that in place of the alkylphenol was used an alkylaminophenol, 
prepared by nitrating and reducing the alkylphenol of Examples 16-29. The 
alkylated aminophenol product is present as a mixture which contains 40% 
diluent oil; 16.10 parts by weight of this oil-containing material is 
used. In some examples the mixture of 0.8 parts Acryloid.TM. 150 and 2.0 
parts Acryloid.TM. 156 were used; this mixture of pour point depressants 
is designated in the following as "M." Samples were observed after storage 
at room temperature or 65.degree. C. at times up to 26 weeks, as indicated 
in Table 3: 
TABLE 3 
______________________________________ 
Ester Ester Results (RT/65.degree.) 
Polyiso- of of other 26 
Ex. butylene Ex. 6 Ex. 1 mat'l 
3, 4, weeks 
______________________________________ 
42 62.55 18.45 -- M -- C/C S/S 
43 56.50 24.60 -- M -- C.sup.a /C 
S/S 
44 50.35 30.75 -- M C/C S/C S/S 
45 44.30 36.80 -- M C/C S/C S/S 
46 32.90 49.00 -- M -- C.sup.a /C 
S/S 
47 56.50 -- 24.60 M S.sup.b /C 
S/C S/S 
48 56.30 24.60 -- A -- C.sup.a /C 
C/Gel 
49 56.30 24.60 -- B C/C C/C C/C 
50 56.30 24.60 -- C C.sup.a /C 
C/C C/C 
______________________________________ 
.sup.a Slight haze 
.sup.b Sample was clear at 2 weeks 
Example 51. A mixture is prepared by mixing and heating, under conditions 
set forth in Example 1, (a) 100 parts by weight of an ethylene/1-octene 
copolymer, containing 2 mole percent 1-octene and having a number average 
molecular weight of about 8,000, (b) 30 parts by weight of a copolymer of 
mixed lower alkyl acrylates (C.sub.1 -C.sub.18, predominantly C.sub.12 
-C.sub.18 alkyl), 5 mole percent of said acrylate groups thereof having 
been converted to amide groups by reaction with 
N,N-diethylpropane-1,3-diamine to form an amide-containing polymer, (c) 52 
parts of mixed cresols alkylated with a polyisobutenyl chain having a 
number average molecular weight of about 2000, the mixture of substituted 
cresols being 25% by weight (giving 13 parts) active material and the 
remainder (giving 39 parts) diluent mineral oil. The mixture is cooled to 
room temperature with stirring, and 104 parts is added of an 
.alpha.-olefin oligomer, 4-6 cSt, prepared from 1-decene, to form a 
concentrate. 
Example 52. A mixture is prepared by mixing and heating, under conditions 
set forth in Example 1, (a) 100 parts by weight of polypropylene, number 
average molecular weight 1000, (b) 30 parts by weight of a copolymer of 50 
mole percent C.sub.4 to C.sub.18 alkyl esters of maleic acid, 43 mole 
percent vinyl acetate, and 7 mole percent of 2(N,N-dimethylamino)ethyl 
methacrylate, and (c) 130 parts by weight of an octapropylene-substituted 
phenol, the substituted phenol being 78% by weight (101 parts) active 
material and the remainder (29 parts) diluent mineral oil. 
Example 53. Example 3 is repeated except that the polyisobutylene 
substituted phenol is replaced by a similar material in which the 
polyisobutylene group has a number average molecular weight of 400. 
Examples 54-81. Blends of the materials shown in Table 4 are prepared by 
mixing at 110.degree.-120.degree. C., then cooling to room temperature. 
The materials are allowed to stand overnight and then examined for 
evidence of separation. The amounts of components shown in Table 4 are 
adjusted to reflect the amount of active chemical; the balance of material 
to total 100% is diluent oil (mineral oil) initially present in some or 
all of the individual components. For each example the hydrocarbon polymer 
("HC Pol.") is as indicated: "PBU" is the polyisobutene of 1000 number 
average molecular weight; "PP" is polypropylene of weight average 
molecular weight 1024; "EPD" is EPDM ethylenepropylene-diene rubber, as in 
Ex. 10, from DuPont; "SDD" is a hydrogenated styrene diene diblock 
copolymer (Shellvis 40.TM.); "SDR" is a hydrogenated styrene diene random 
block copolymer, as in Ex. 14, from BASF. The nitrogen-containing polymer 
("N pol.") is that of Example 1 (designated E1) or that of Example 6 
(designated E6). In each case the substituted phenol is phenol alkylated 
with a 1000 mw polyisobutenyl chain ("phenol"). 
TABLE 4 
______________________________________ 
HC pol. N pol. HC-phenol 
Ex. type, % type, % % Appearance 
______________________________________ 
54 PBU 55 E6 15.3 0 sharp separation 
55 PBU 50 E6 13.6 10 diffuse separation 
56 PBU 44 E6 12.2 20 clear - no separation 
57 PP 50 E6 17.0 0 hazy - no clear 
separation 
58 PP 45 E6 15.3 10 clear - no separation 
59 PP 40 E6 13.6 20 clear - no separation 
60 EPD 5.0 E6 17.0 0 diffuse separation 
61 EPD 4.5 E6 15.3 10 diffuse separation 
62 EPD 4.0 E6 13.6 20 hazy separation 
63 EPD 3.0 E6 17.0 20 hazy (no separation) 
64 SDD 3.0 E6 17.0 0 hazy separation 
65 SDD 2.7 E6 15.3 10 slight haze (some separa- 
tion but diffuse) 
66 SDD 2.4 E6 13.6 20 very slight hazy 
67 SDD 1.8 E6 17.0 20 very slight hazy 
68 SDR 4.8 E6 13.6 0 separated 
69 SDR 4.0 E6 10.2 20 slight haze 
70 SDR 2.4 E6 17.0 20 haze 
71 PP 55 E1 18.4 0 hazy; separates 
72 PP 50 E1 16.4 10 clear 
73 PP 44 E1 14.8 20 clear 
74 PBU 55 E1 18.4 0 hazy, diffuse, separation 
75 PBU 50 E1 16.4 10 hazy, diffuse, separation 
76 PBU 44 E1 14.8 20 clear 
77 PBU 44 E1 14.8 10 separates 
+PP 10 
78 EPD 5 E1 20.5 0 hazy, separation 
79 EPD 4 E1 16.4 20 hazy, diffuse/separation 
80 EPD 3 E1 20.5 20 hazy, diffuse/separation 
81 PP 50 E1 20.5 0 separation 
______________________________________ 
Each of the documents referred to above is incorporated herein by 
reference. Except in the Examples, or where otherwise explicitly 
indicated, all numerical quantities in this description specifying amounts 
of materials, reaction conditions, molecular weights, number of carbon 
atoms, and the like, are to be understood as modified by the word "about." 
Unless otherwise indicated, each chemical or composition referred to 
herein should be interpreted as being a commercial grade material which 
may contain the isomers, by-products, derivatives, and other such 
materials which are normally understood to be present in the commercial 
grade. However, the amount of each chemical component is presented 
exclusive of any solvent or diluent oil which may be customarily present 
in the commercial material, unless otherwise indicated. As used herein, 
the expression "consisting essentially of" permits the inclusion of 
substances which do not materially affect the basic and novel 
characteristics of the composition under consideration.