Concentrates with high molecular weight dispersants and their preparation

Concentrates for lubricating oil compositions are prepared by mixing at elevated temperature:(i) at least one high molecular weight ashless dispersant;(ii) at least one oil-soluble overbased metal detergent; and (iii) at least one other concentrate additive provided that the additive is first mixed with the detergent or the dispersant.

FIELD OF THE INVENTION 
This invention relates to oleaginous compositions useful in fuel and 
lubricating oil compositions. More particularly, this invention relates to 
oleaginous concentrates containing high molecular weight dispersants and 
their preparation thereof. 
BACKGROUND OF THE INVENTION 
This invention relates to lubricating oil compositions, e.g. automatic 
transmission fluids, heavy duty oils suitable for gasoline and diesel 
engines and cranckcase oils. These lubricating oil formulations 
conventionally contain several different types of additives that will 
supply the characteristics that are required in the formulations. Among 
these types of additives are included viscosity index improvers, 
antioxidants, corrosion inhibitors, detergents, dispersants, pour point 
depressants, antiwear agents, etc. 
In the preparation of lubricating oil compositions, it is common practice 
to introduce the additives in the form of 10 to 80 mass %, e.g. 20 to 80 
mass % active ingredient concentrates in hydrocarbon oil, e.g. mineral 
lubricating oil, or other suitable solvent. Usually these concentrates are 
subsequently diluted with 3 to 100, e.g. 5 to 40 parts by weight of 
lubricating oil, per part by weight of the concentrate to form finished 
lubricating oil compositions. 
It is convenient to provide a so-called "additive package" comprising two 
or more of the above mentioned additives in a single concentrate in a 
hydrocarbon oil or other suitable solvent. However, a problem with 
preparing additive packages is that some additives tend to interact with 
each other. For example, dispersants having a high molecular weight or a 
high functionality ratio, for example, of 1.3 or higher, have been found 
to interact with other additives in additive packages, particularly 
overbased metal detergents. This interaction causes a viscosity increase 
upon blending, which may be followed by subsequent growth or increase of 
viscosity with time. In some instances, the interaction results in 
gelation. The viscosity increase can hamper pumping, blending and handling 
of the additive package. Although the additive package can be further 
diluted with more diluent oil to reduce viscosity in order to offset the 
effect of interaction, dilution reduces the economy of using an additive 
package by increasing shipping, storage and other handling costs. 
U.S. Pat. No. 4,398,880 describes a process for improving the stability of 
oleaginous concentrates in the form of additive packages comprising 
ashless dispersants, particularly polyisobutylene containing dispersants, 
in combination with overbased metal detergents in which the additives are 
contacted in a lubricating oil basestock at a temperature of from 
100.degree. C. to 160.degree. C. for 1 to 10 hours. The resultant 
heat-treated blend is then cooled to a temperature of 85.degree. C. or 
below and further mixed with copper antioxidant additives, zinc 
dihydrocarbyldithiophosphate antiwear additives and, optionally, other 
additives useful in lubricating oil compositions. The process enables the 
stability of the additive package to be improved to the extent that the 
tendency for phase separation is substantially reduced. 
However, the molecular weight of the dispersant used in U.S. Pat. No. 
4,398,880 is relatively low. The number average molecular weight of the 
polyisobutylene polymer used in the examples to make the dispersant is 
only 1725. The resulting dispersant number average molecular weight can be 
calculated to be approximately 3900 (e.g., 2 moles isobutylene polymer 
(MW=1725)+2 moles maleic anhydride (MW=98)+1 mole polyethyleneamine 
(MW=250)=2(1725)+2(98)+1(250).about.3900). The significant increase in 
viscosity due to the dispersant/detergent interaction, which will be 
described in more detail below, does not occur until the molecular weight 
of the polyisobutylene derivatized dispersant is much higher (i.e., 
approximately 7000). 
Another problem with concentrates containing high molecular weight 
dispersants is their stability. As dispersant size increase, concentrates 
containing these high molecular weight dispersants are unstable and have a 
tendency to phase separate resulting in sediments. The phase separation 
reduces the performance of the concentrate, and the sediments increase the 
cost of shipping and handling. 
There is a trend in the industry to go to higher molecular weight 
dispersants because they have improved dispersant properties to satisfy 
more rigorous performance requirements in the automobile industry. 
However, when higher molecular weight dispersants are used in 
concentrates, they interact with the colloidal overbased detergents to 
form a complex. This complex substantially increases the viscosity of the 
concentrate, which could result is blending difficulties unless the 
blending procedure is carefully designed. 
Below is a simplified description of a concentrate containing an overbased 
detergent and an ashless dispersant. When an overbased detergent is added 
to an oil-based solvent, a colloidal structure forms containing 
hydrophilic groups and lipophilic groups, where the lipophilic groups 
extend out in the oil-based solvent. The ashless dispersant also contains 
hydrophilic groups and lipophilic groups. At sufficiently high 
concentrations, the dispersant could interact with the overbased detergent 
colloidal structure to form a dispersant/detergent complex where the 
hydrophilic groups of the overbased metal detergent colloidal structure 
interacts with the hydrophilic groups of the ashless dispersant. 
Not wishing to be bound by any theory, it is believed that a 
dispersant/detergent complex could cause an increase in viscosity because 
lipophilic groups of the ashless dispersant of one complex can interact 
with lipophilic groups of another complex. This results in an effective 
high molecular weight aggregate complex that increases the viscosity of 
the concentrate. The viscosity may rise uncontrollably to the extent that 
gels may form that are impossible to blend into a finished lubricating oil 
composition. The latter effect can evidence itself as the Weissenberg 
Effect. The Weissenberg Effect occurs when the viscosity of the 
concentrate significantly increases such that composition is seen to rise 
up the shaft of the mixing blades during blending. 
It should be noted that the increase in viscosity would not occur if the 
concentration of the complex, or the molecular weight of the ashless 
dispersant in the concentrate is low. If the concentration of the complex 
is low (i.e., if the concentrate is dilute), there is sufficient space 
between the complexes such that the lipophilic groups of the dispersants 
will not interact. Likewise, if the molecular weight of the ashless 
dispersants is low, the lipophilic groups are too small to interact with 
each other. Thus, for example, a high molecular weight dispersant in a 
concentrate that is sufficiently dilute may not have a blending problem 
because there is sufficient space between the complexes such that an 
aggregate complex will not form. In contrast, a low molecular weight 
dispersant could have a blending problem in a highly concentrated 
composition because the space between the complexes is small. At typical 
additive package concentrations, the blending problems will not typically 
occur until the number average molecular weight of the dispersant is over 
about 7000 for polyisobutylene derivatized dispersants and over about 3000 
for poly(alpha-olefin) derivatized dispersants. 
Therefore, it is an objective of the present invention to provide a 
concentrated additive package composition that contains a higher molecular 
weight ashless dispersant and an overbased metal detergent than previously 
has been available due to viscosity considerations. It is another object 
of the present invention to provide a concentrate containing a high 
molecular weight ashless detergent and an overbased metal detergent that 
has good stability and does not phase separate. It is also an object of 
the present invention to provide a process for preparing the concentrate 
composition. 
SUMMARY OF THE INVENTION 
This invention relates to a phase stable, oleaginous additive concentrate 
comprising a diluent oil, at least one borated or unborated ashless 
dispersant where the ashless dispersant has a hydrodynamic radius of about 
8 to 40 nm, at least one overbased metal detergent, and at least one other 
concentrate additive. The weight ratio of the ashless dispersant to the 
overbased metal detergent is about 1:1 to 8:1, and the sum of the ashless 
dispersant and the overbased metal detergent on an active ingredient basis 
is about 25 to 50 wt. % based upon the total weight of said concentrate. 
In the present invention, unless otherwise specified, the amount of 
ashless detergent, overbased detergent and other concentrate additives are 
on an active ingredient basis. 
This invention also relates to a process for preparing the additive 
concentrate described above. The inventors of the present invention have 
surprisingly discovered that when the high molecular weight ashless 
dispersant or overbased detergent are first mixed with at least one of the 
concentrate additives, the concentrate is readily blendable and no 
Weissenberg effect is observed. In addition, when the ashless dispersant 
is first mixed with the other additives and the detergent is blended last, 
the tendency for phase separation is significantly reduced. It is believed 
that the present invention provides a concentrated additive package 
composition that contains a higher molecular weight ashless dispersant 
than previously has been available due to viscosity and phase separation 
concerns. 
DETAILED DESCRIPTION 
The present invention solves the problem of increased viscosity and phase 
separation concerns when a high molecular weight dispersants and overbased 
metal detergents are blended to form a concentrate. The concentrate 
comprises a diluent oil, at least borated or unborated one ashless 
dispersant where the ashless dispersant has a hydrodynamic radius of about 
8 to 40 nm, at least one overbased metal detergent and at least one other 
concentrate additive. The weight ratio of the ashless dispersant to the 
metal detergent is about 1:1 to 8:1, and the sum of the ashless dispersant 
and the metal detergent is about 25 to 50 wt. % based upon the total 
weight of said concentrate. 
The inventors have discovered that when the ashless dispersant or the 
overbased detergent is first mixed with at least one other additive, they 
are readily blendable and do not show a Weissenberg effect. In addition, 
when the dispersant is first blended with at least one other additive, and 
the detergent is blended last, the concentrate is stable with minimal or 
no phase separation. 
Although not wishing to be bound by any theory, it is believed that when 
other additives are first mixed with either the dispersant or the 
detergent, they compete with the binding sites on the detergent or 
dispersant, and block the complex between the detergent and the dispersant 
from forming. It is also believed that the additives aid in breaking up 
the aggregate complexes that do form. Therefore, it is not dilution that 
prevents the formation of the aggregate complex, but the specific 
properties of the concentrate additives of this invention that prevents 
the complexes from forming. 
The hydrodynamic radius of the present invention is a convenient way to 
measure the size of the dispersant. The hydrodynamic radius is a measure 
of the volume of space occupied by the dispersant. The longer the 
hydrodynamic radius of the dispersant, the more likely it will interact 
with other dispersants that are complexed with the overbased metal 
detergent. 
The concept of hydrodynamic radius is a more useful measure of the volume 
occupied by the dispersant than just molecular weight. This is because the 
volume occupied by the dispersant, depends, in part, on the amount and 
length of branches in the polymer dispersant. A dispersant that has many 
branches may have a high molecular weight, but its hydrodynamic radius may 
not be large because a significant part of the molecular weight is 
concentrated in the branches. In contrast, a low molecular weight polymer 
dispersant may have a large hydrodynamic radius because it contains few 
branches, and has a long polymer backbone. Therefore, a better indication 
of the tendency of polymer dispersants to interact is hydrodynamic radius 
rather than molecular weight. It is believed that the hydrodynamic radius 
of the dispersants used in the present invention is larger than those that 
have been previously used in concentrate additive packages. 
The hydrodynamic radius of the dispersants may be measured by the technique 
of dynamic light scattering (hereinafter "DLS") which is described in B. 
J. Berne and R. Pecora, Dynamic Light Scattering (Krieger, Malabar, Fla., 
1990) and in D. E. Dahneke, Measurement of Suspended to Particles by 
Quasielastic Light Scattering (Wiley, New York, 1983). The dispersants of 
the present invention should be measured in heptane or other comparable 
solvents in concentrations of 0.1 to 1 Wt. %. For most dispersants, the 
measurement temperature has little impact on the measurement results, and 
the temperature can range from room temperature to 60.degree. C. However, 
with ethylene based dispersants, the hydrodynamic radius measurement 
should be performed at 60.degree. C. to eliminate association of ethylene 
segments. 
The additives, as components of the concentrate, may be mixed in any order, 
provided that the additives are first mixed with either the dispersant or 
the detergent. For example, the dispersant and other concentrate additives 
are first mixed together and the detergent is added last, or the detergent 
and other concentrate additives are first mixed together and then the 
dispersant is added. Preferably, the detergent is added last because this 
improves the stability of the concentrate. 
In order for the concentrate to be oleaginous, the additives may be in 
solution in an oleaginous carrier or such a carrier may be provided 
separately or both. Examples of suitable carriers are oils of lubricating 
viscosity, such as described in detail hereinafter, and aliphatic, 
naphthenic and aromatic hydrocarbons. 
The dispersant, detergent and other additives of the present invention must 
be "oil-soluble" or "oil-dispersible" in the oleaginous carrier or oil of 
lubricating viscosity, but these descriptions do not mean that they are 
soluble, dissolvable, miscible or capable of being suspended in the oil in 
all proportions. They do mean, however, that they are stable and soluble 
in the oil to an extent sufficient to exert their intended effect in the 
environment in which the lubricating oil composition is employed. 
Moreover, the additional incorporation of other additives such as those 
described hereinafter may affect their oil-solubility or dispersability. 
The concentrate of the present invention is prepared at elevated 
temperatures, i.e. above ambient temperature. The blending temperature 
should be about 50.degree. to 150.degree. C., preferably about 50.degree. 
to 120.degree. C., more preferably about 60.degree. to 120.degree. C. and 
even more preferably about 60.degree. to 100.degree. C. Although energy is 
saved at low temperatures, practical considerations dictate the most 
convenient temperature that can be used. Thus, where any additive is used 
that is solid at ambient temperature, it is usually more convenient to 
raise its temperature to a temperature at which it flows, rather than 
dissolving it in oil prior to addition to the other additives. 
Temperatures of 100.degree. C. or more can be employed if any additive is 
more conveniently handled at such temperatures. 
The components are advantageously held at the mixing temperature for a time 
sufficient to achieve a homogenous mixture thereof. This can usually be 
effected within 2 hours with the present invention. 
One or more further lubricating oil additives, desirable for conferring a 
full range of properties may be added to the concentrate. These additives 
preferably include corrosion inhibitors, metal dihydrocarbyl 
dithiophosphates, antioxidants, antiwear agents, friction modifiers, 
viscosity modifiers, a low base number metal detergent having a TBN less 
than 50, and mixtures thereof. The temperature at which these further 
additives are added will depend on the stability of the particular 
additives. Preferably, the temperature for blending further additives is 
about 50 to 85.degree. C. For example, when one of the additives is zinc 
dihydrocarbyl dithiophosphate, the blending temperature should be about 
60.degree. to 85.degree. C. 
Boron may usefully be provided in the concentrate, for example in the form 
of a borated ashless dispersant, or in the form of an additional 
boron-containing compound or both. 
The concentrate of the present invention can be incorporated into a 
lubricating oil composition in any convenient way. Thus, they can be added 
directly to an oil of lubricating viscosity by dispersing or dissolving 
them in the oil at the desired concentrations of the dispersant and 
detergent, respectively. Such blending can occur at ambient temperature or 
elevated temperatures. Alternatively, the composite can be blended with a 
suitable oil-soluble solvent and base oil to form a further concentrate 
which is then blended with an oil of lubricating viscosity to obtain the 
final lubricating oil composition. 
The concentrate of the present invention will typically contain (on an 
active ingredient (A.I.) basis) from 3 to 50 mass %, and preferably from 
10 to 40 mass % dispersant additive, from 3 to 45 mass %, and preferably 
from 5 to 30 mass %, overbased metal detergent based on the concentrate 
weight. The concentrate will typically contain an ashless dispersant to 
overbased metal detergent weight ratio on an active ingredient basis of 
about 0.1:1 to 12:1, preferably about 0.5:1 to 10:1, more preferably about 
1:1 to 8:1, and even still more preferably about 1:1 to 4:1. 
The sum of the detergent and dispersant on an active ingredient basis is 
typically from 20 to 70 wt. %, preferably about 25 to 60 wt. %, more 
preferably about 25 to 55 wt. %, even more preferably about 30 to 55 wt. 
%, still more preferably about 30 to 50 wt. % and even still more 
preferably about 35 to 50 wt. % based on the total weight of the 
concentrate. 
The practical concentration (sum of the detergent and dispersant) will 
depend, in part, on the size of the dispersant. If the dispersant size is 
large, e.g., a hydrodynamic radius of 15 to 40 nm, the practical 
concentration in the present invention will typically range from about 25 
to 40 wt. %. If the size of the dispersant is smaller, e.g., a 
hydrodynamic radius of about 8 to 40 nm, the practical concentration will 
typically be about 30 to 50 wt. %. 
In a preferred embodiment, the overbased detergent is pre-treated, prior to 
introduction to the blending process, with about 1 to 50 wt. %, relative 
to the overbased detergent, of a pretreatment additive selected from the 
group consisting of an polyamine-derivatized poly(isobutylene) ashless 
dispersant having a number average molecular weight of about 500 to 6000 
and a poly(isobutylene)succinic anhydride with a molecular weight of about 
300 to 2500. Preferably, the pretreatment additive is a 
poly(isobutylene)succinic anhydride with a molecular weight of about 300 
to 2500. 
The components of the invention will now be discussed in further detail as 
follows: 
Ashless Dispersants 
The high molecular weight ashless dispersants in the concentrate of the 
present invention include the range of ashless dispersants known as 
effective for adding to lubricant oils for the purpose of reducing the 
formation of deposits in gasoline or diesel engines. Preferably, "high 
molecular weight" dispersant means having a number average molecular 
weight of greater than 3000, such as between 3000 and 20,000. The exact 
molecular weight ranges will depend on the type of polymer used in the 
dispersants. For example, for a polyisobutylene derivatized dispersant, a 
high molecular weight dispersant means having a number average molecular 
weight of about 7000 to 20,000. A high molecular weight poly(alpha-olefin) 
derivatized dispersant means having a molecular weight from about 3000 to 
20,000. It is believed that the high molecular dispersants of the present 
invention have not previously been used with overbased metal detergents in 
the concentrations needed to prepare a concentrate due to stability 
problems and the uncontrollable rise in viscosity during blending. 
As previously discussed, a useful measure of the size of the dispersant is 
hydrodynamic radius (R.sub.H). In the present invention, the hydrodynamic 
radius may range from about 8 to 40 nm, such as 10, 12 or 15 to 40 nm. It 
is believed that the above ranges for the dispersants are higher than 
those that have been previously used in concentrates. 
Typical commercially available polyisobutylene based dispersants contain 
polyisobutylene polymers having a number average molecular weight ranging 
from 900 to 2300, functionalized by maleic anhydride, (MW=98), and 
derivatized with polyamines having a molecular weight of about 100 to 350. 
Each dispersant contains 1.5 to 2.5 polyisobutylene polymers per 
dispersant. Thus, the molecular weight of the polyisobutylene derivatized 
dispersant can be calculated and ranges from about 1600 to 6300. For 
example, with a dispersant averaging about 2.5 polymers per dispersant, 
the molecular weight of the dispersant can be calculated to be: 2.5 moles 
polyisobutylene (MW=2300)+2.5 moles maleic anhydride (MW=98)+1 mole 
polyamine (350) which gives a molecular weight of about 6300. For 
comparison, a polyisobutylene based dispersant having a number average 
molecular weight of about 5000 has a hydrodynamic radius of about 5.5 nm. 
In cases where the molecular weight of the dispersant can not be readily 
estimated from the molecular weight of the starting materials, e.g., in 
more complex chain extended systems, an empirical measurement of molecular 
weight and hydrodynamic radius must be made. 
The ashless dispersant of the present invention includes an oil soluble 
polymeric long chain hydrocarbon backbone having functional groups that 
are capable of associating with particles to be dispersed. Typically, the 
dispersants comprise amine, alcohol, amide, or ester polar moieties 
attached to the polymer backbone often via a bridging group. The ashless 
dispersant may be, for example, selected from oil soluble salts, esters, 
amino-esters, amides, imides, and oxazolines of long chain hydrocarbon 
substituted mono and dicarboxylic acids or their anhydrides; 
thiocarboxylate derivatives of long chain hydrocarbons; long chain 
aliphatic hydrocarbons having a polyamine attached directly thereto; and 
Mannich condensation products formed by condensing a long chain 
substituted phenol with formaldehyde and polyalkylene polyamine. 
The long chain hydrocarbyl substituted mono- or dicarboxylic acid material, 
i.e. acid, anhydride, or ester, used in the invention includes long chain 
hydrocarbon, generally a polyolefin, substituted with an average of at 
least about 0.8, (e.g., about 0.8 to 2.0) generally from about 1.0 to 2.0, 
preferably 1.05 to 1.25, 1.1 to 1.2, moles per mole of polyolefin, of an 
alpha or beta unsaturated C..sub.4 to C.sub.10 dicarboxylic acid, or 
anhydride or ester thereof, such as fumaric acid, itaconic acid, maleic 
acid, maleic anhydride, chloromaleic acid, dimethyl fumarate, chloromaleic 
anhydride, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, 
etc. 
Preferred olefin polymers for reaction with the unsaturated dicarboxylic 
acids are polymers comprising a major molar amount of C.sub.2 to C.sub.10, 
e.g. C.sub.2 to C.sub.5 monoolefin. Such olefins include ethylene, 
propylene, butylene, isobutylene, pentene, octene-1, styrene, etc. The 
polymers can be homopolymers such as polyisobutylene, as well as 
copolymers of two or more of such olefins such as copolymers of: ethylene 
and propylene; butylene and isobutylene; propylene and isobutylene; etc. 
Other copolymers include those in which a minor molar amount of the 
copolymer monomers, e.g., 1 to 10 mole %, is a C.sub.4 to C.sub.18 
non-conjugated diolefin, e.g., a copolymer of isobutylene and butadiene; 
or a copolymer of ethylene, propylene and 1,4-hexadiene; etc. 
Processes for reacting polymeric hydrocarbons with unsaturated carboxylic 
acids, anhydrides or esters and the preparation of derivatives from those 
compounds are disclosed in U.S. Pat. No. 3,087,936, U.S. Pat. No. 
3,172,892, U.S. Pat. No. 3,215,707, U.S. Pat. No. 3,231,587, U.S. Pat. No. 
3,231,587, U.S. Pat. No. 3,272,746, U.S. Pat. No. 3,275,554, U.S. Pat. No. 
3,381,022, U.S. Pat. No. 3,442,808, U.S. Pat. No. 3,56,804, U.S. Pat. No. 
3,912,764, U.S. Pat. No. 4,110,349, U.S. Pat. No. 4,234,435 and 
GB-A-1440219. 
A preferred class of ashless dispersants are ethylene alpha-olefin 
copolymers and alpha-olefin homo-, co- and terpolymers prepared using new 
metallocene catalyst chemistry, which may have a high degree (e.g. &gt;30%) 
of terminal vinylidene unsaturation is described in U.S. Pat. Nos. 
5,128,056, 5,151,204, 5,200,103, 5,225,092, 5,266,223, 5,334,775; 
WO-A-94/19436, 94/13709; and EP-A-440506, 513157, 513211. These 
dispersants are described as having superior viscometric properties as 
expressed in a ratio of CCS viscosity to kV 100.degree. C. 
The term "alpha-olefin" is used herein to denote an olefin of the formula 
##STR1## 
wherein R' is preferably a C.sub.1 -C.sub.18 alkyl group. The requirement 
for terminal vinylidene unsaturation refers to the presence in the polymer 
of the following structure: 
##STR2## 
wherein Poly is the polymer chain and R is typically a C.sub.1 -C.sub.18 
alkyl group, typically methyl or ethyl. Preferably the polymers will have 
at least 50%, and most preferably at least 60%, of the polymer chains with 
terminal vinylidene unsaturation. As indicated in WO-A-94/19426, 
ethylene/1-butene copolymers typically have vinyl groups terminating no 
more than about 10 percent of the chains, and internal mono-unsaturation 
in the balance of the chains. The nature of the unsaturation may be 
determined by FTIR spectroscopic analysis, titration or C-13 NMR. 
The oil-soluble polymeric hydrocarbon backbone may be a homopolymer (e.g., 
polypropylene) or a copolymer of two or more of such olefins (e.g., 
copolymers of ethylene and an alpha-olefin such as propylene or butylene, 
or copolymers of two different alpha-olefins). Other copolymers include 
those in which a minor molar amount of the copolymer monomers, e.g., 1 to 
10 mole %, is an .alpha.,.omega.-diene, such as a C.sub.3 to C.sub.22 
non-conjugated diolefin (e.g., a copolymer of isobutylene and butadiene, 
or a copolymer of ethylene, propylene and 1,4-hexadiene or 
5-ethylidene-2-norbornene). Atactic propylene oligomers of the present 
invention have a number average molecular weight of from about 3000 to 
10000 may also be used as well as heteropolymers such as polyepoxides. 
One preferred class of olefin polymers is polybutenes and specifically 
poly-n-butenes, such as may be prepared by polymerization of a C.sub.4 
refinery stream. Other preferred classes of olefin polymers are ethylene 
alpha-olefins (EAO) copolymers that preferably contain 1 to 50 mole % 
ethylene, and more preferably 5 to 48 mole % ethylene. Such polymers may 
contain more than one alpha-olefin and may contain one or more C.sub.3 to 
C.sub.22 diolefins. Also useable are mixtures of EAO's of varying ethylene 
content. Different polymer types, e.g., EAO, may also be mixed or blended, 
as well as polymers differing in number average molecular weight 
components derived from these also may be mixed or blended. 
Particularly preferred copolymers are ethylene butene copolymers. 
Preferably, the olefin polymers and copolymers may be prepared by various 
catalytic polymerization processes using metallocene catalysts which are, 
for example, bulky ligand transition metal compounds of the formula: 
EQU [L].sub.m M[A].sub.n 
where L is a bulky ligand; A is a leaving group, M is a transition metal, 
and m and n are such that the total ligand valency corresponds to the 
transition metal valency. Preferably the catalyst is four co-ordinate such 
that the compound is ionizable to a 1.sup.+ valency state. Such 
polymerizations, catalysts, and cocatalysts or activators are described, 
for example, in U.S. Pat. Nos. 4,530,914, 4,665,208, 4,808,561, 4,871,705, 
4,897,455, 4,937,299, 4,952,716, 5,017,714, 5,055,438, 5,057,475, 
5,064,802, 5,096,867, 5,120,867, 5,124,418, 5,153,157, 5,198,401, 
5,227,440, 5,241,025; EP-A-129368, 277003, 277004, 420436, 520732; and 
WO-A-91/04257, 92/00333, 93/08199, 93/08221, 94/07928 and 94/13715, herein 
incorporated by reference. 
The oil-soluble polymeric hydrocarbon backbone may be functionalized to 
incorporate a functional group into the backbone of the polymer, or as one 
or more groups pendant from the polymer backbone. The functional group 
typically will be polar and contain one or more hetero atoms such as P, O, 
S, N, halogen, or boron. It can be attached to a saturated hydrocarbon 
part of the oil-soluble polymeric hydrocarbon backbone via substitution 
reactions or to an olefinic portion via addition or cycloaddition 
reactions. Alternatively, the functional group can be incorporated into 
the polymer in conjunction with oxidation or cleavage of the polymer chain 
end (e.g., as in ozonolysis). 
Useful functionalization reactions include: halogenation of the polymer at 
an olefinic bond and subsequent reaction of the halogenated polymer with 
an ethylenically unsaturated functional compound (e.g., maleation where 
the polymer is reacted with maleic acid or anhydride); reaction of the 
polymer with an unsaturated functional compound by the "ene" reaction 
absent halogenation; reaction of the polymer with at least one phenol 
group (this permits derivatization in a Mannich base-type condensation); 
reaction of the polymer at a point of unsaturation with carbon monoxide 
using a Koch-type reaction to introduce a carbonyl group in an iso or neo 
position; reaction of the polymer with the functionalizing compound by 
free radical addition using a free radical catalyst; copolymerization of 
the polymer with the functionalizing compound, (e.g., maleic anhydride), 
with or without low molecular weight olefins via free radical initiation; 
reaction with a thiocarboxylic acid derivative; and reaction of the 
polymer by air oxidation methods, epoxidation, chloroamination, or 
ozonolysis. 
The functionalized oil-soluble polymeric hydrocarbon backbone is then 
further derivatized with a nucleophilic reactant such as an amine, 
amino-alcohol, alcohol, metal compound or mixture thereof to form a 
corresponding derivative. Useful amine compounds for derivatizing 
functionalized polymers comprise at least one amine and can comprise one 
or more additional amine or other reactive or polar groups. These amines 
may be hydrocarbyl amines or may be predominantly hydrocarbyl amines in 
which the hydrocarbyl group includes other groups, e.g., hydroxy groups, 
alkoxy groups, amide groups, nitriles, imidazoline groups, and the like. 
Particularly useful amine compounds include mono- and polyamines, e.g. 
polyalkylene and polyoxyalkylene polyamines of about 2 to 60, conveniently 
2 to 40 (e.g., 3 to 20), total carbon atoms and about 1 to 12, 
conveniently 3 to 12, and preferably 3 to 9 nitrogen atoms in the 
molecule. Mixtures of amine compounds may advantageously be used such as 
those prepared by reaction of alkylene dihalide with ammonia. Preferred 
amines are aliphatic saturated amines, including, e.g., 1,2-diaminoethane; 
1,3-diaminopropane; 1,4-diaminobutane; 1,6-diaminohexane; polyethylene 
amines such as diethylene triamine; triethylene tetramine; tetraethylene 
pentamine; and polypropyleneamines such as 1,2-propylene diamine; and 
di-(1,2-propylene)triamine. 
Other useful amine compounds include: alicyclic diamines such as 
1,4-di(aminomethyl) cyclohexane, and heterocyclic nitrogen compounds such 
as imidazolines. A particularly useful class of amines are the polyamido 
and related amido-amines as disclosed in U.S. Pat. Nos. 4,857,217; 
4,956,107; 4,963,275; and 5,229,022. Also usable is 
tris(hydroxymethyl)amino methane (THAM) as described in U.S. Pat. Nos. 
4,102,798; 4,113,639; 4,116,876; and UK 989,409. Dendrimers, star-like 
amines, and comb-structure amines may also be used. Similarly, one may use 
the condensed amines disclosed in U.S. Pat. No. 5,053,152. The 
functionalized polymer is reacted with the amine compound according to 
conventional techniques as described in EP-A 208,560; U.S. Pat. No. 
4,234,435 and U.S. Pat. No. 5,229,022. 
The functionalized oil-soluble polymeric hydrocarbon backbones also may be 
derivatized with hydroxy compounds such as monohydric and polyhydric 
alcohols or with aromatic compounds such as phenols and naphthols. 
Polyhydric alcohols are preferred, e.g., alkylene glycols in which the 
alkylene radical contains from 2 to 8 carbon atoms. Other useful 
polyhydric alcohols include glycerol, mono-oleate of glycerol, 
monostearate of glycerol, monomethyl ether of glycerol, pentaerythritol, 
dipentaerythritol, and mixtures thereof. An ester dispersant may also be 
derived from unsaturated alcohols such as allyl alcohol, cinnamyl alcohol, 
propargyl alcohol, 1-cyclohexane-3-ol, and oleyl alcohol. Still other 
classes of the alcohols capable of yielding ashless dispersants comprise 
the ether-alcohols and including, for example, the oxy-alkylene, 
oxy-arylene. They are exemplified by ether-alcohols having up to 150 
oxy-alkylene radicals in which the alkylene radical contains from 1 to 8 
carbon atoms. The ester dispersants may be di-esters of succinic acids or 
acidic esters, i.e., partially esterified succinic acids, as well as 
partially esterified polyhydric alcohols or phenols, i.e., esters having 
free alcohols or phenolic hydroxyl radicals. An ester dispersant may be 
prepared by one of several known methods as illustrated, for example, in 
U.S. Pat. No. 3,381,022. 
One preferred group of dispersant is poly(alpha olefin) dispersants. They 
are preferably employed in the invention as polyamine-derivatized 
poly(alpha-olefin) dispersants having a number average molecular weight of 
about 3000 to 20,000, preferably about 4000 to 15,000 and more preferably 
about 5000 to 10,000, or a weight average molecular weight of about 6,000 
to 50,000, preferably about 8,000 to 40,000 and more preferably 10,000 to 
30,000. One convenient method to measure molecular weight is gel 
permeation chromatography (GPC), which additionally provides molecular 
weight distribution information (see W. W. Yau, J. J. Kirkland and D. D. 
Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, 
New York, 1979). Another useful method, particularly for lower molecular 
weight polymers, is vapor pressure osmometry (see, e.g., ASTM D3592). 
In a preferred embodiment the poly(alpha olefin) dispersant is derived from 
an ethylene/butene alpha-olefin polymer having a number average molecular 
weight of about 4,000 to 15000 or a weight average molecular weight of 
about 8,000 to 40,000. 
Another preferred group of ashless dispersants are those derived from 
polyisobutylene substituted with succinic anhydride groups and reacted 
with polyethylene amines, e.g. tetraethylene pentamine, pentaethylene e.g. 
polyoxypropylene diamine, trismethylolaminomethane and pentaerythritol, 
and combinations thereof. One particularly preferred dispersant 
combination involves a combination of (A) polyisobutylene substituted with 
succinic anhydride groups and reacted with (B) a hydroxy compound, e.g. 
pentaerythritol, (C) a polyoxyalkylene polyamine, e.g. polyoxypropylene 
diamine, or (D) a polyalkylene polyamine, e.g. polyethylene diamine and 
tetraethylene pentamine using about 0.3 to about 2 moles either (B), (C) 
or (D) per mole of A. Another preferred dispersant combination involves 
the combination of (A) polyisobutenyl succinic anhydride with (B) a 
polyalkylene polyamine, e.g. tetraethylene pentamine, and (C) a polyhydric 
alcohol or polyhydroxy-substituted aliphatic primary amine, e.g. 
pentaerythritol or trismethylolaminomethane as described in U.S. Pat. No. 
3,632,511. 
Preferably, the polyamine-derivatized polyisobutylene dispersant has a 
number average molecular weight of about 7000 to 20000, preferably about 
9000 to 20,000 and more preferably about 12,000 to 20,000, or a weight 
average molecular weight of about 17,000 to 50,000, preferably about 
20,000 to 40,000 and more preferably about 25,000 to 40,000. 
The above polyisobutylene-derivatized dispersant may also be used as a 
pretreatment additive for the overbased detergent when the number average 
molecular weight is about 500 to 6000. In addition, the polyisobutylene 
substituted anhydride may also be used as a pretreatment additive when the 
number average molecular weight is about 300 to 2500. 
Another class of ashless dispersants comprises Mannich base condensation 
products. Generally, these are prepared by condensing about one mole of an 
alkyl-substituted mono- or polyhydroxy benzene with about 1 to 2.5 moles 
of carbonyl compounds (e.g., formaldehyde and paraformaldehyde) and about 
0.5 to 2 moles polyalkylene polyamine as disclosed, for example, in U.S. 
Pat. No. 3,442,808. Such Mannich condensation products may include a 
polymer product of a metallocene catalyzed polymerization as a substituent 
on the benzene group or may be reacted with a compound containing such a 
polymer substituted on a succinic anhydride, in a manner similar to that 
shown in U.S. Pat. No. 3,442,808. 
Examples of functionalized and/or derivatized olefin polymers based on 
polymers synthesized using metallocene catalyst systems are described in 
publications identified above. 
The dispersant can be further post-treated by a variety of conventional 
post treatments such as boration, as generally taught in U.S. Pat. Nos. 
3,087,936 and 3,254,025. This is readily accomplished by treating an acyl 
nitrogen-containing dispersant with a boron compound selected from the 
group consisting of boron oxide, boron halides, boron acids and esters of 
boron acids, in an amount to provide from about 0.1 atomic proportion of 
boron for each mole of the acylated nitrogen composition to about 20 
atomic proportions of boron for each atomic proportion of nitrogen of the 
acylated nitrogen composition. Usefully the dispersants contain from about 
0.05 to 2.0 wt. %, e.g. 0.05 to 0.7 wt. % boron based on the total weight 
of the borated acyl nitrogen compound. The boron, which appears be in the 
product as dehydrated boric acid polymers (primarily (HBO.sub.2).sub.3), 
is believed to attach to the dispersant imides and diimides as amine salts 
e.g., the metaborate salt of the diimide. Boration is readily carried out 
by adding from about 0.05 to 4, e.g., 1 to 3 wt. % (based on the weight of 
acyl nitrogen compound) of a boron compound, preferably boric acid, 
usually as a slurry, to the acyl nitrogen compound and heating with 
stirring at from 135.degree. to 190.degree. C., e.g., 
140.degree.-170.degree. C., for from 1 to 5 hours followed by nitrogen 
stripping. Alternatively, the boron treatment can be carried out by adding 
boric acid to a hot reaction mixture of the dicarboxylic acid material and 
amine while removing water. 
Also, boron may be provided separately, for example as a boron ester or as 
a boron succinimide, made for example from a polyisobutylene succinic 
anhydride, where the polymer has a molecular weight of from 450 to 700. 
Oil-Soluble Metal Detergent 
Metal-containing or ash-forming detergents function both as detergents to 
reduce or remove deposits and as acid neutralizers or rust inhibitors, 
thereby reducing wear and corrosion and extending engine life. Detergents 
generally comprise a polar head with a long hydrophobic tail, with the 
polar head comprising a metal salt of an acidic organic compound. The 
salts may contain a substantially stoichiometric amount of the metal in 
which case they are usually described as normal or neutral salts, and 
would typically have a total base number or TBN (as may be measured by 
ASTM D2896) of from 0 to 80. It is possible to include large amounts of a 
metal base by reacting an excess of a metal compound such as an oxide or 
hydroxide with an acidic gas such as carbon dioxide. The resulting 
overbased detergent comprises neutralized detergent as the outer layer of 
a metal base (e.g. carbonate) micelle. The detergents of the present 
invention are overbased detergents that have a TBN of 150 or greater, and 
typically about 250 to 450 or more. 
Detergents that may be used in the present invention include oil-soluble 
overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, 
salicylates, and naphthenates and other oil-soluble carboxylates of a 
metal, particularly the alkali or alkaline earth metals, e.g., sodium, 
potassium, lithium, calcium, and magnesium. The most commonly used metals 
are calcium and magnesium, which may both be present in detergents used in 
a lubricant, and mixtures of calcium and/or magnesium with sodium. 
Particularly convenient metal detergents are overbased calcium sulfonates, 
calcium phenates and sulfurized phenates and salicylates having a TBN of 
about 150 to 450. In the practice of the present invention, combinations 
of surfactants, e.g., sulfonates and phenates, and combination of 
overbased and neutral detergents may also be used. 
Sulfonates may be prepared from sulfonic acids which are typically obtained 
by the sulfonation of alkyl substituted aromatic hydrocarbons such as 
those obtained from the fractionation of petroleum or by the alkylation of 
aromatic hydrocarbons. Examples included those obtained by alkylating 
benzene, toluene, xylene, naphthalene, diphenyl or their halogen 
derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene. 
The alkylation may be carried out in the presence of a catalyst with 
alkylating agents having from about 3 to more than 70 carbon atoms. The 
alkaryl sulfonates usually contain from about 9 to about 80 or more carbon 
atoms, preferably from about 16 to about 60 carbon atoms per alkyl 
substituted aromatic moiety. 
The oil soluble sulfonates or alkaryl sulfonic acids may be neutralized 
with oxides, hydroxides, alkoxides, carbonates, carboxylate, sulfides, 
hydrosulfides, nitrates, borates and ethers of the metal. The amount of 
metal compound is chosen having regard to the desired TBN of the final 
product but typically ranges from about 100 to 220 wt % (preferably at 
least 125 wt %) of that stoichiometrically required. 
Metal salts of phenols and sulfurized phenols are prepared by reaction with 
an appropriate metal compound such as an oxide or hydroxide and neutral or 
overbased products may be obtained by methods well known in the art. 
Sulfurized phenols may be prepared by reacting a phenol with sulfur or a 
sulfur containing compound such as hydrogen sulfide, sulfur monohalide or 
sulfur dihalide, to form products which are generally mixtures of 
compounds in which 2 or more phenols are bridged by sulfur containing 
bridges. 
The detergent may have a particle diameter size in the range of about 4 to 
40 nm, preferably about 4 to 30 nm and more preferably about 6 to 20 nm. 
The overbased metal dispersant diameter size can be measured using the 
small angle neutron scattering technique as described in I. Markovic, R. 
H. Ottewill, D. J Cebula, I. Field and J. F. Marsh, "Small angle neutron 
scattering studies on non-aqueous dispersions of calcium carbonate", 
Colloid & Polymer Science, 262:648-656 (1984). 
Oil of Lubricating Viscosity 
The oil of lubricating viscosity, useful for making concentrates of the 
invention or for making lubricating oil compositions therefrom, may be 
selected from natural (vegetable, animal or mineral) and synthetic 
lubricating oils and mixtures thereof. It may range in viscosity from 
light distillate mineral oils to heavy lubricating oils such as gas engine 
oil, mineral lubricating oil, motor vehicle oil, and heavy duty diesel 
oil. Generally, the viscosity of the oil ranges from 2 centistokes to 30 
centistokes, especially 5 centistokes to 20 centistokes, at 100.degree. C. 
Natural oils include animal oils and vegetable oils (e.g., castor, lard 
oil) liquid petroleum oils and hydrorefined, solvent-treated or 
acid-treated mineral lubricating oils of the paraffinic, napthenic and 
mixed paraffinic-napthenic types. Oils of lubricating viscosity derived 
from coal or shale are also useful base oils. 
Synthetic lubricating oils include hydrocarbon oils and halo-substituted 
hydrocarbon oils such as polymerized and interpolymerized olefins (e.g., 
polybutylenes, polypropylenes, propylene-isobutylene copolymers, 
chlorinated polybutylenes, poly(1-hexenes), poly(1-octenes), 
poly(1-decenes)); alkylbenzenes (e.g., dodecylbenzenes, 
tetradecylbenzenes, dinonylbenzenes, di(2-ethylhexyl)benzenes); 
polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenols); and 
alkylated diphenyl ethers and alkylated diphenyl sulfides and the 
derivatives; analogs and homologs thereof. 
Alkylene oxide polymers and interpolymers and derivatives thereof where the 
terminal hydroxyl groups have been modified by esterification, 
etherification, etc., constitute another class of known synthetic 
lubricating oils. These are exemplified by polyoxyalkylene polymers 
prepared by polymerization of ethylene oxide or propylene oxide, the alkyl 
and aryl ethers of these polyoxyalkylene polymers (e.g., 
methylpolyisopropylene glycol ether having an average molecular weight of 
1000, diphenyl ether of poly-ethylene glycol having a molecular weight of 
500-1000, diethyl ether of polypropylene glycol having a molecular weight 
of 1000-1500); and mono- and polycarboxylic esters thereof, for example, 
the acetic acid esters, mixed C.sub.3 -C.sub.8 fatty acid esters and 
C.sub.13 Oxo acid diester of tetraethylene glycol. 
Another suitable class of synthetic lubricating oils comprises the esters 
of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic 
acids and alkenyl succinic acids, maleic acid, azelaic acid, subericacid, 
sebasic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic 
acid, alkylmalonic acids, alkenyl malonic acids) with a variety of 
alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 
2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, 
propylene glycol). Specific examples of these esters include dibutyl 
adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, 
dilsooctyl azelate, disodecyl azelate, dioctyl phthalate, didecyl 
phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid 
dimer, and the complex ester formed by reacting one mole of sebacic acid 
with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic 
acid. 
Esters useful as synthetic oils also include those made from C.sub.5 to 
C.sub.12 monocarboxylic acids and polyols and polyol ethers such as 
neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol 
and tripentaerythritol. 
Silicon-based oils such as the polyalkyl-, polyaryl-, polyakoxy-, or 
polyaryloxysiloxne oils and silicate oils comprise another useful class of 
synthetic lubricants; they include tetraethyl silicate, tetraisopropyl 
silicate, tetra-(2-ethylhexyl)silicate, 
tetra-(4-methyl-2-ethylhexyl)silicate, 
tetra-(p-tert-butyl-phenyl)silicate, hexa-(4-methyl-2-pentoxy)disiloxane, 
poly(methyl)siloxanes and poly(methylphenyl)siloxanes. Other synthetic 
lubricating oils include liquid esters of phosphorus-containing acids 
(e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of 
decylphosphonic acid) and polymeric tetrahydrofurans. 
Unrefined, refined and rerefined oils can be used in the lubricants of the 
present invention. Unrefined oils are those obtained directly from a 
natural or synthetic source without further purification treatment. For 
example, a shale oil obtained directly from retorting operations, a 
petroleum oil obtained directly from distillation or ester oil obtained 
directly from an esterification process and used without further treatment 
would be an unrefined oil. Refined oils are similar to the unrefined oils 
except they have been further treated in one or more purification steps to 
improve one or more properties. Many such purification techniques, such as 
distillation, solvent extraction, acid or base extraction, filtration and 
percolation are known to those skilled in the art. Rerefined oils are 
obtained by processes similar to those used to obtain refined oils applied 
to refined oils which have been already used in service. Such rerefined 
oils are also known as reclaimed or reprocessed oils and often are 
additionally processed by techniques for removal of spent additives and 
oil breakdown products. 
Other Additive Components 
As indicated above, additional additives may be incorporated in the 
composites of the invention to enable them to meet particular 
requirements. Examples of additives which may be included in the 
lubricating oil compositions are metal rust inhibitors, viscosity index 
improvers, corrosion inhibitors, other oxidation inhibitors, friction 
modifiers, other dispersants, anti-foaming agents, anti-wear agents, pour 
point depressants, and rust inhibitors. Some are discussed in further 
detail below. 
Dihydrocarbyl dithiophosphate metal salts are frequently used as antiwear 
and antioxidant agents. The metal may be an alkali or alkaline earth 
metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. 
The zinc salts are most commonly used in lubricating oil in amounts of 0.1 
to 10, preferably 0.2 to 2 wt %, based upon the total weight of the 
lubricating oil composition. They may be prepared in accordance with known 
techniques by first forming a dihydrocarbyl dithiophosphoric acid (DDPA), 
usually by reaction of one or more alcohol or a phenol with P.sub.2 
S.sub.5 and then neutralizing the formed DDPA with a zinc compound. For 
example, a dithiophosphoric acid may be made by reacting mixtures of 
primary and secondary alcohols. Alternatively, multiple dithiophosphoric 
acids can be prepared where the hydrocarbyl groups on one are entirely 
secondary in character and the hydrocarbyl groups on the others are 
entirely primary in character. To make the zinc salt, any basic or neutral 
zinc compound could be used but the oxides, hydroxides and carbonates are 
most generally employed. Commercial additives frequently contain an excess 
of zinc due to use of an excess of the basic zinc compound in the 
neutralization reaction. 
The preferred zinc dihydrocarbyl dithiophosphates are oil soluble salts of 
dihydrocarbyl dithiophosphoric acids and may be represented by the 
following formula: 
##STR3## 
wherein R and R' may be the same or different hydrocarbyl radicals 
containing from 1 to 18, preferably 2 to 12, carbon atoms and including 
radicals such as alkyl, alkenyl, aryl, arylalkyl, alkaryl and 
cycloaliphatic radicals. Particularly preferred as R and R' groups are 
alkyl groups of 2 to 8 carbon atoms. Thus, the radicals may, for example, 
be ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, 
l-hexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, 
butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. In order to 
obtain oil solubility, the total number of carbon atoms (i.e. R and R') in 
the dithiophosphoric acid will generally be about 5 or greater. The zinc 
dihydrocarbyl dithiophosphate can therefore comprise zinc dialkyl 
dithiophosphates. 
Oxidation inhibitors or antioxidants reduce the tendency of mineral oils to 
deteriorate in service. Oxidative deterioration can be evidenced by sludge 
in the lubricant, varnish-like deposits on the metal surfaces, and by 
viscosity growth. Such oxidation inhibitors include hindered phenols, 
alkaline earth metal salts of alkylphenolthioesters having preferably 
C.sub.5 to C.sub.12 alkyl side chains, calcium nonylphenol sulphide, oil 
soluble phenates and sulfurized phenates, phosphosulfurized or sulfurized 
hydrocarbons, phosphorous esters, metal thiocarbamates, oil soluble copper 
compounds as described in U.S. Pat. No. 4,867,890, and 
molybdenum-containing compounds. 
Aromatic amines having at least two aromatic groups attached directly to 
the nitrogen constitute another class of compounds that is frequently used 
for antioxidancy. While these materials may be used in small amounts, 
preferred embodiments of the present invention are free of these 
compounds. They are preferably used in only small amounts, i.e., up to 0.4 
wt %, or more preferably avoided altogether other than such amount as may 
result as an impurity from another component of the composition. 
Typical oil soluble aromatic amines having at least two aromatic groups 
attached directly to one amine nitrogen contain from 6 to 16 carbon atoms. 
The amines may contain more than two aromatic groups. Compounds having a 
total of at least three aromatic groups in which two aromatic groups are 
linked by a covalent bond or by an atom or group (e.g., an oxygen or 
sulphur atom, or a --CO--, --SO.sub.2 -- or alkylene group) and two are 
directly attached to one amine nitrogen also considered aromatic amines 
having at least two aromatic groups attached directly to the nitrogen. The 
aromatic rings are typically substituted by one or more substituents 
selected from alkyl, cycloalkyl, alkoxy, aryloxy, acyl, acylamino, 
hydroxy, and nitro groups. The amount of any such oil soluble aromatic 
amines having at least two aromatic groups attached directly to one amine 
nitrogen should preferably not exceed 0.4 wt % active ingredient. 
Representative examples of suitable viscosity modifiers are 
polyisobutylene, copolymers of ethylene and propylene, polymethacrylates, 
methacrylate copolymers, copolymers of an unsaturated dicarboxylic acid 
and a vinyl compound, interpolymers of styrene and acrylic esters, and 
partially hydrogenated copolymers of styrene/isoprene, styrene/butadiene, 
and isoprene/butadiene, as well as the partially hydrogenated homopolymers 
of butadiene and isoprene. 
Friction modifiers and fuel economy agents which are compatible with the 
other ingredients of the final oil may also be included. Examples of such 
materials are glyceryl monoesters of higher fatty acids, for example, 
glyceryl mono-oleate; esters of long chain polycarboxylic acids with 
diols, for example, the butane diol ester of a dimerized unsaturated fatty 
acid; oxazoline compounds; and alkoxylated alkyl-substituted monoamines, 
diamines and alkyl ether amines, for example, ethoxylated tallow amine and 
ethoxylated tallow ether amine. 
A viscosity index improver dispersant functions both as a viscosity index 
improver and as a dispersant. Examples of viscosity index improver 
dispersants include reaction products of amines, for example polyamines, 
with a hydrocarbyl-substituted mono -or dicarboxylic acid in which the 
hydrocarbyl substituent comprises a chain of sufficient length to impart 
viscosity index improving properties to the compounds. In general, the 
viscosity index improver dispersant may be, for example, a polymer of a 
C.sub.4 to C.sub.24 unsaturated ester of vinyl alcohol or a C.sub.3 to 
C.sub.10 unsaturated mono-carboxylic acid or a C.sub.4 to C.sub.10 
di-carboxylic acid with an unsaturated nitrogen-containing monomer having 
4 to 20 carbon atoms; a polymer of a C.sub.2 to C.sub.20 olefin with an 
unsaturated C.sub.3 to C.sub.10 mono- or di-carboxylic acid neutralized 
with an amine, hydroxyamine or an alcohol; or a polymer of ethylene with a 
C.sub.3 to C.sub.20 olefin further reacted either by grafting a C.sub.4 to 
C.sub.20 unsaturated nitrogen-containing monomer thereon or by grafting an 
unsaturated acid onto the polymer backbone and then reacting carboxylic 
acid groups of the grafted acid with an amine, hydroxy amine or alcohol. 
Examples of dispersants and viscosity index improver dispersants may be 
found in European Patent Specification No. 24146 B. 
Pour point depressants, otherwise known as lube oil flow improvers, lower 
the minimum temperature at which the fluid will flow or can be poured. 
Such additives are well known. Typical of those additives which improve 
the low temperature fluidity of the fluid are C.sub.8 to C.sub.18 dialkyl 
fumarate/vinyl acetate copolymers, and polymethacrylates. Foam control can 
be provided by an antifoamant of the polysiloxane type, for example, 
silicone oil or polydimethyl siloxane. 
Some of the above-mentioned additives can provide a multiplicity of 
effects; thus for example, a single additive may act as a 
dispersant-oxidation inhibitor. This approach is well known and need not 
be further elaborated herein. 
When lubricating concentrate contain one or more of the above-mentioned 
additives, each additive is typically blended into the base oil in an 
amount, which enables the additive to provide its desired function. 
The amount of the above mentioned additives, other than the overbased metal 
detergent, ashless dispersant and diluent oil, can range from about 0.1 to 
50 wt. %, preferably about 0.2 to 40 wt. %, more preferably about 0.5 to 
30 wt. % and even more preferably about 1 to 20 wt. %. 
The concentrate may be further added to a lubricating oil in concentration 
resulting in a final lubricating oil composition which may employ from 5 
to 25 mass %, preferably 5 to 18 mass %, typically 10 to 15 mass % of the 
concentrate, the remainder being oil of lubricating viscosity. 
Representative effected amounts of such additives, when used in crankcase 
lubricants, are listed below. All the values listed are stated as mass 
percent active ingredient. 
______________________________________ 
MASS % MASS % 
ADDITIVE (Broad) (Preferred) 
______________________________________ 
Ashless Dispersant 0.1-20 1-8 
Metal Detergents 0.1-15 0.2-9 
Corrosion Inhibitor 0-5 0-1.5 
Metal Dihydrocarbyl Dithiophosphate 0.1-6 0.1-4 
Antioxidant 0-5 0.01-2 
Pour Point Depressant 0.01-5 0.01-1.5 
Antifoaming Agent 0-5 0.001-0.15 
Supplemental Antiwear Agents 0-1.0 0-0.5 
Friction Modifier 0-5 0-1.5 
Viscosity Modifier 0.01-10 0.25-3 
Basestock Balance Balance 
______________________________________ 
All weight percents expressed herein (unless otherwise indicated) are based 
on active ingredient (A.l.) content of the additive, and/or upon the total 
weight of any additive-package, or formulation which will be the sum of 
the A.l. weight of each additive plus the weight of total oil or diluent.

This invention is explained below in further detail with references to 
examples, which are not by way of limitation, but by way of illustration. 
EXAMPLE 1 
Blend Components 
In the following example, oleaginous additive concentrates were made by 
blending the following dispersant, detergent and additives. A dispersant 
was made by functionalizing an ethylene-butene copolymer (46 wt. % 
ethylene) with a carbonyl group introduced by Koch reaction, derivatized 
with polyamine and borated according to the procedure described in 
WO-A-94/13709. The number average molecular weight of the dispersant was 
approximately 6000 and the hydrodynamic radius, as measured by the dynamic 
light scattering technique at 60.degree. C., was approximately 30 to 40 
nm. A overbased detergent containing magnesium sulfonate with a TBN of 400 
and a diameter of 10.+-.2 nm as measured the small angle neutron 
scattering technique. The weight ratio of the dispersant to the detergent 
was 3:1 on an active ingredient basis and the sum of the overbased 
detergent and ashless dispersant on an active ingredient basis is about 27 
wt. % based on the total weight of the concentrate. 
The concentrate additives used in this example included an antifoam agent, 
anti-oxidants, a demulsifier, zinc dihydrocarbyl dithiophosphates and 
friction modifiers. 
EXAMPLE 2 
Blending Procedure 
The oleaginous concentrate blending procedures were performed at 60.degree. 
C. In the dispersant last procedure, the overbased detergent was mixed 
with the concentrate additives listed in Example 1 and allowed to mix for 
about 1 hour. The dispersant was then added and blended for a further 
hour. The blend was observed for the Weissenberg effect. The blend was 
stored at 60.degree. C. for 8 weeks and then tested for sediment content, 
which is an indication of phase separation. 
The same methods were used in the detergent last procedure except that the 
dispersant was first mixed with the concentrate additives for about one 
hour, followed by the detergent. 
In addition to the above procedures, the detergent was optionally mixed 
with a pretreatment additives for 8 hours at 95.degree. C. before being 
mixed with the blend. The pretreatment additive was a 
poly(isobutylene)succinic anhydride having a number average molecular 
weight of approximately 2300. The pretreatment additive was blended at 10 
wt. % based on the total weight of the detergent. 
The blending results for the concentrates are shown in Table 1 below. 
TABLE 1 
______________________________________ 
Pretreatment 
Blendability 
Wt. % sediments 
Blending procedure additive (Weissenberg) (8 weeks at 60.degree. 
______________________________________ 
C.) 
Dispersant last 
No Blendable, (No 
1.7% 
Weissenberg) 
Dispersant last Yes Blendable, (No 0.2% 
Weissenberg) 
Detergent last No Blendable (No 0.01% 
Weissenberg) 
Detergent last Yes Blendable, (No Trace 
Weissenberg) 
Control No Unblendable N/A (unblendable) 
(conventional (Large 
according to Weissenberg) 
U.S. Pat. No. 
4,938,880) 
______________________________________ 
The results in Table 1 show that when the conventional method is used 
(i.e., the dispersant and detergent are mixed together before adding the 
additives), the concentrate is unblendable. However, when the additives 
are first mixed with either the detergent or the dispersant, the 
concentrate is blendable. In addition, the results surprisingly and 
unexpectedly show that when the detergent is blended last, the amount of 
the sediments are greatly reduced. Furthermore, the results also show that 
the amount of sediments is reduced by pretreating the detergent with 
polyisobutylene succinic anhydride. Therefore, due to the procedure of the 
present method, it is now possible to used high molecular weight 
dispersants and overbased detergents at concentrations used in additive 
packages. 
The foregoing is illustrative of the present invention and is not construed 
as limiting thereof. The invention is defined by the following claims with 
equivalents of the claims to be included therein.