Polyolefin block copolymer viscosity modifier

A viscosity modifier comprising a low molecular weight block copolymer including A blocks and B blocks, wherein the A blocks comprise at least about 93 wt. % polyethylene and the B blocks comprise a copolymer of between about 40 wt. % to 75 wt. % ethylene and at least one other .alpha.-olefin; wherein the resulting block copolymer has an average ethylene content of between about 60 wt. % to 80 wt. %.

The present invention relates to novel block copolymers particularly useful 
as oil viscosity modifiers that display an improved balance of thickening 
efficiency and shear stability. These block copolymers comprise blocks of 
substantially pure polyethylene, and blocks of copolymers containing 
ethylene and at least one other .alpha.-olefin. Lubricating oils 
containing the unique viscosity modifiers and the process for producing 
the block copolymers are also provided. 
BACKGROUND OF THE INVENTION 
Ethylene-propylene copolymers are important commercial products and are 
widely used as viscosity modifiers (VM) in lubricating oils. A motor oil 
should not be too viscous at low temperatures so as to avoid serious 
frictional losses, facilitate cold starting, and provide free oil 
circulation at engine start-up. On the other hand, too thin an oil at high 
temperature will cause excessive engine wear and oil consumption. It is 
most desirable to employ a lubricating oil which experiences little or no 
viscosity change in response to changes in oil temperature. 
Over the last thirty years, efforts have been made to improve the 
thickening efficiency (TE) and shear stability (SSI) performance of 
lubricating oil viscosity modifiers. The thickening efficiency is a 
measure of the thickening power of the polymer, and is defined as: 
EQU TE=(2/C) ln ((kv of polymer+oil)/(kv of oil))/ln (2) 
wherein kv is the kinematic viscosity at 100.degree. C., C is the 
concentration in grams/100 grams of solution, and the log is consistently 
either natural or base 10. 
The TE of a viscosity modifier depends somewhat on the particular base oil 
and other formulating components in the base oil, as well as the polymer 
concentration. For the purposes of this application, the oil is designated 
to be a solvent 100N, such as FTN135 (a product of Exxon Chemicals) 
containing no components other than the viscosity modifier of the present 
invention, with a polymer concentration sufficient to double the viscosity 
of the base oil at 100.degree. C. 
The shear stability is a measure of how well the polymer resists 
degradation due to the mechanical stresses applied by an engine. The 
SAE-ASTM-DIN test used to measure this tendency for degradation is the 
Kurt Orbahn Shear Stability Test (ASTM D3945-86, hereinafter "KO SSI"). 
Previous efforts to simultaneously improve TE and SSI of ethylene, 
.alpha.-olefin copolymers have involved increasing the ethylene content of 
the polymer and narrowing the molecular weight distribution (MWD). The 
upper limit for ethylene content is determined by the requirement that the 
dilute polymer has to be soluble, or remain in suspension with no 
macroscopic gellation,in oil down to a temperature of at least -40.degree. 
C. Thus, pure polyethylene is beyond the limit. For simple statistical 
copolymers, the average ethylene content cannot be made higher than about 
76 wt. % (determined in accordance with ASTM D3900-95) without causing the 
copolymer to become insoluble in oil. At these levels, however, pour point 
problems are encountered. However, it has been demonstrated that even when 
the ethylene content exceeds only about 61 wt. %, many of the methylene 
sequences in the viscosity modifier are of a length which allows them to 
co-crystallize with paraffin waxes in the oil, thereby leading to 
undesirably high viscosities and gellation of the oil. Typically, 
conventional ethylene, .alpha.-olefin viscosity modifiers that can be 
employed to formulate lubricating oils having pour points of -30.degree. 
C. or below are restricted to an average ethylene content of no greater 
than about 56 wt. %, unless the molecules possess an intramolecular 
compositional distribution (CD) tailored to improve such properties, as is 
disclosed in U.S. Pat. No. 4,900,461. 
The present inventors have developed a unique viscosity modifier, formed of 
a block copolymer comprising a first block of substantially pure 
polyethylene and a second block of a copolymer of ethylene and another 
.alpha.-olefin; such that the block copolymer has a high average ethylene 
content so as to provide an excellent balance of thickening efficiency and 
shear stability. More importantly, however, is the fact that this unique 
block copolymer viscosity modifier of the present invention possesses 
unusual solubility characteristics, agglomerating above wax 
crystallization temperatures, thereby preventing its co-crystallizing with 
paraffin waxes in the oil and the undesirable formation of high 
viscosities or gellation of the oil. Furthermore, the present inventors 
have discovered that when blocks of substantially pure ethylene are used 
as the A block of a block copolymer, the ethylene sequences in the B 
block, even in the 50 wt. % range of B block ethylene content, will not 
crystallize with paraffins and cause high oil viscosity at temperatures 
below about 0.degree. C. This allows for an increased ethylene content in 
the B blocks, an average ethylene content in the block copolymer of over 
70 wt. % and performance characteristics that are substantially 
independent of the type of wax contained in the lubricant basestock. 
In summary, these viscosity modifiers exhibit excellent TE-SSI performance, 
and can be added to the oils to form a viscosity modified lubricant with 
excellent low temperature properties. 
The present invention also provides a polymer with resistance to cold flow 
during storage and resistance to agglomerization during recovery from the 
polymerization solvent and many additional advantages which shall become 
apparent as described below. 
SUMMARY OF THE INVENTION 
The present invention is directed to a novel viscosity modifier comprising 
a block copolymer including an A block and B block. The A block comprises 
at least about 93 wt. % polyethylene. The B block comprises a copolymer of 
between about 40 wt. % to 85 wt. % ethylene and at least one other 
.alpha.-olefin. These block copolymers have a total average ethylene 
content of between about 60 wt. % to 80 wt. % and provide a viscosity 
modifier exhibiting the following properties: TE equal to or greater than 
1.5, preferably between about 2.0 to 4.0; KO SSI less than 30, preferably 
between about 10 and 30; formulated oil pour points less than -25.degree. 
C., as specified by oil grade; and an undiluted polymer melting point that 
is preferably greater than 112.degree. C., as measured by the maximum 
departure from baseline in a differential scanning calorimeter (DSC), 
using the DSC operating conditions described below. 
The semicrystalline viscosity modifiers of the present invention are also 
novel in that the methylene sequences therein are of sufficient length, 
and in sufficient concentration such that in the bulk polymer, crystalline 
lamallae with dimensions greater than 0.5 microns are observed by 
transmission electron microscopy (TEM) with ruthenium tetroxide 
(RuO.sub.4) treatment to produce contrast. 
Preferably, the viscosity modifier will have a weight average molecular 
weight of between about 60,000 to about 150,000 and a bulk viscosity (pure 
polymer, no diluent) that is greater than 10.sup.6 poise at 110.degree. C. 
when measured at a shear strain rate of 10.sup.-3 sec.sup.-1 or less, and 
will be formed with a B block comprising a copolymer of ethylene and 
propylene. 
Preferably, the A block will comprise less than about 25 wt. % of said 
block copolymer. Such a block copolymer can provide a viscosity modifier 
exhibiting an SSI as defined by the following formula: 
EQU log SSI=alogTE+b(max in dI(M)/dlog M)+c 
wherein: 
a=1.8 
b=0.29 
c=1.2 
I(M)=integral molecular weight distribution wherein 
##EQU1## 
M=molecular weight 
SSI performance depends on TE, ethene content, and molecular weight 
distribution (MWD). The above formula defines a TE-SSI performance that 
has heretofore not been attainable with ethene-.alpha.-olefin polymers 
meeting all other performance criteria for conventional lube oil viscosity 
modifiers. 
The present invention also includes lubricant compositions prepared from at 
least one synthetic or natural oil base stock and the above defined 
viscosity modifier. The lubricant is preferably one selected from the 
group consisting of crankcase oils, hydraulic fluids, turbine oils, gear 
oils, functional fluids, industrial oils and catapult oils. A particularly 
advantageous crankcase lubricant can be provided by adding to a synthetic 
oil and/or natural oil base stock, the unique viscosity modifier of the 
present invention wherein the A block comprises 15 to 25 wt. % of the 
block copolymer. This viscosity modifier can provide the formulated oil 
with a combination of a High Temperature High Shear viscosity (HTHS) value 
and a low kinematic viscosity (kv) at 80.degree. C. that will promote fuel 
economy. The Viscosity Index, as measured by ASTM D2270-93, is 
exceptionally high for oils formulated with the PE-EP block copolymers of 
the present invention, with values in excess of 170 being readily 
attainable. 
The present invention also provides a novel process for forming the 
above-described block copolymer viscosity modifiers, in which the block 
copolymer is formed in a mix-free reactor, in the presence of a vanadium 
catalyst system including a vanadium compound and an organoaluminum 
compound.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention is directed to a novel viscosity modifier comprising 
a block copolymer including A blocks and B blocks. The A blocks comprise 
at least about 93 wt. % ethylene. The B blocks comprise a copolymer of 
between about 40 wt. % to 85 wt. % ethylene and at least one other 
.alpha.-olefin. These block copolymers have an average ethylene content of 
between 60 wt. % to 80 wt. % and provide a viscosity modifier exhibiting 
the following properties: TE equal to or greater than about 1.3, 
preferably between about 2.0 to 4.0; KO SSI less than about 30 and an 
undiluted polymer melting point greater than about 112.degree. C., 
preferably between about 112.degree. C. to 118.degree. C. Formulated oils 
comprising the novel viscosity modifier can provide a pour point less than 
about -30.degree. C., while simultaneously providing exceptional TE-SSI 
performance that results from a high average ethene content and a narrow 
molecular weight distribution (MWD). 
The A block comprises about 93 wt. % polyethylene. The remainder of the A 
block comprises an .alpha.-olefin comonomer. The A block is preferably 
present in the block copolymer in the range of between about 10 to 30 wt. 
%. More preferably, the A block will be present in the block copolymer in 
the range of between about 14 to 25 wt. %, most preferably in the range of 
16 to 22 wt. %. The upper bound is dictated by the need for oil 
solubility, especially after the polymer chains are mechanically broken by 
forces within the engine. The lower bound is dictated by the requirement 
that the polymer form particles in a hot water slurry during the polymer 
manufacturing process. 
The B block comprises a copolymer of ethylene and at least one other 
.alpha.-olefin. This other .alpha.-olefin is one having between about 
about 3 to 8 carbon atoms, e.g., propylene, butene-1, pentene-1, etc. For 
economic and TE-SSI performance reasons, .alpha.-olefins having between 
about 3 to 6 carbon atoms are preferred. The most preferred .alpha.-olefin 
is propylene. The use of propylene as the .alpha.-olefin of the B block 
provides for the highest weight % ethylene content. The B block can 
comprise an average ethylene content in the range between about 40 to 90 
wt. %, preferably 50 to 85 wt. % and most preferably 60 to 80 wt. %. 
The block copolymer will have an average ethylene content of between about 
60 to 80 wt. %, preferably 65 to 75 wt. %, and most preferably 68 to 73 
wt. %. These block copolymers will have a weight average molecular weight 
in the range between about 50,000 to 150,000, preferably 80,000 to 
130,000. The block copolymers of the present invention will have a melting 
point in the range between about 110.degree. C. to 125.degree. C., 
preferably 114.degree. C. to 118.degree. C. Further, these block 
copolymers will contain methylene sequences that are of sufficient length, 
and in sufficient concentration such that, at 20.degree. C., the bulk 
polymer will contain crystalline lamallae with dimensions greater than 0.5 
microns when examined by transmission electron microscopy (TEM) with 
ruthenium tetroxide (RuO.sub.4) treatment, as described, for example, by 
Khandpur et al. in "Transmission Electron Microscopy of Saturated 
Hydrocarbon Block Copolymers", Journal of Polymer Science: Part B: Polymer 
Physics, Vol. 33, 247-252 (1995), which is incorporated herein by 
reference. 
The novel viscosity modifier of the present invention has a thickening 
efficiency of greater than about 1.5, preferably 1.5 to 4.0, and most 
preferably 2.0 to 3.5. When the viscosity modifier of the present 
invention is added to a base stock lubricant, the pour point of the 
resulting composition remains below about -25.degree. C., preferably below 
-30.degree. C., and most preferably below -33.degree. C., depending on the 
SAE grade specified. 
Previously, statistical copolymers of ethylene and propylene, when used as 
viscosity modifiers, have displayed low temperature performance 
characteristics that depended strongly on the average ethene content of 
the polymer. Pour points (PP) and minirotary viscosity (MRV) measurements 
in the TP1 temperature cycle have indicated poor performance in finished 
lubricating oils when the ethene content of the copolymer was above about 
55 wt. %. The only exception has been found in the performance of 
intramolecularly tapered molecules, as described in U.S. Pat. No. 
4,900,461. However, even in that case of these tapered molecules, 
satisfactory performance is only observed over a narrow range of ethene 
content and degree of crystallinity, in the semi-crystalline portion of 
the molecule. 
Surprisingly, it has been found that the degree of crystallinity (at 20 to 
25.degree. C.) in the semicrystalline portion of the ethylene-propylene 
portion of the molecule in the B block can be varied over a wide range 
(e.g. from 0 to at least 20 wt %), with little effect on the pour point or 
TP1 viscosity. This characteristic of the copolymers of the present 
invention is beneficial, as it allows for the use of a reduced amount of 
wax crystal modifier (LOFI) in the formulated lubricant composition. Heats 
of fusion of the semicrystalline ethylene-propylene section of the 
inventive copolymers are within a range of about 0 to about 25 J/gm of 
polymer. 
Although applicants do not wish to be bound by any specific theory, it can 
be deduced from the foregoing that the polyethylene portion of the 
copolymer, which has a melting point far above that of the semicrystalline 
ethylene-propylene segment, controls the configuration and solubility of 
the copolymer molecule, in the basestock. At low temperatures at which wax 
crystallizes, below 10.degree. C., the viscosity modifier polymer has 
already crystallized into too small a configuration to interact with the 
wax in a manner that will raise the viscosity or pour point of the 
lubricating composition. This is easily observed as a decrease in the 
contribution of the polymer to oil viscosity as the temperature is 
lowered. 
It is critical that the PE-EP block structure not contain sequences of 
ethene in the EP block that are of high enough melting point that they 
will cocrystallize with the PE block. In such a case, the polymer can 
crystallize into a network that will gel the oil at high temperatures even 
before the wax crystallizes. Thus, the melting point of any ethane 
sequences in the EP block must be at least 30 to 40.degree. C. below that 
of the PE block. It is also advantageous to have the crystalline portion, 
if any, of the EP block be adjacent to the PE block rather than at the end 
of the EP block that is furthest from the juncture between the PE and EP 
blocks. The present polymers are designed to avoid network formation and 
are thus not suitable for use as thermoplastic elastomers. In terms of 
ethene content, the EP block should not contain any segments of 5000 
molecular weight or higher that have an ethene content above 80 wt. %. 
The formulated lubricant according to the present invention comprises a 
base stock selected from the group consisting of: mineral oils, highly 
refined mineral oils, alkylated mineral oils, poly alpha olefins, 
polyalkylene glycols, diesters and polyol esters, and a viscosity 
modifying present in an amount between about 0.4 wt. % to 1.8 wt. %, 
preferably 0.5 wt. % to 1.5 wt. %, and most preferably 0.6 wt. % to 1.4 
wt. %. The lubricant composition may further contain other lubricant 
additives. 
CRANKCASE LUBRICATING OILS 
The inventive viscosity modifier composition can be used in the formulation 
of crankcase lubricating oils (i.e., passenger car motor oils, heavy duty 
diesel motor oils, and passenger car diesel oils) for spark-ignited and 
compression-ignited engines. The additives listed below are typically used 
in such amounts so as to provide their normal attendant functions. Typical 
amounts for individual components are also set forth 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 
Supplemental anti-oxidant 
0-5 0.01-1.5 
Pour Point Depressant 
0.01-5 0.01-1.5 
Anti-Foaming Agent 0-5 0.001-0.15 
Supplemental Anti-wear Agents 
0-0.5 0-0.2 
Friction Modifier 0-5 0-1.5 
Viscosity Modifier 0.5-1.8 0.9-1.4 
Synthetic and/or Mineral Base Stock 
Balance Balance 
______________________________________ 
The individual additives may be incorporated into a base stock in any 
convenient way. Thus, each of the components can be added directly to the 
base stock by dispersing or dissolving it in the base stock at the desired 
level of concentration. Such blending, in general, will occur at an 
elevated temperature. To dissolve the block copolymers herein, the base 
oil and viscosity modifiers should be heated to above 110.degree. C. to 
facilitate dissolution. With high shear mixers, however, the block 
copolymers can be dissolved at a lower temperature. 
Preferably, all the additives except for the viscosity modifier and the 
pour point depressant are blended into a concentrate or additive package 
described herein as the additive package, that is subsequently blended 
with the base stock and viscosity modifier to make finished lubricant. Use 
of such concentrates is conventional. The concentrate will typically be 
formulated to contain the additive(s) in proper amounts to provide the 
desired concentration in the final formulation when the concentrate is 
combined with a predetermined amount of base lubricant. Storage and 
blending of the block copolymer concentrate should be carried out at a 
temperature of 60.degree. C. or higher, as determined by the polymer 
concentration and T.sub.m. 
The final crankcase lubricating oil formulation may employ from 2 to 20 
mass % and preferably 5 to 10 mass %, typically about 7 to 8 mass % of the 
concentrate with the remainder being base stock and additive package. 
The ashless dispersant comprises oil soluble polymeric hydrocarbyl groups 
bearing 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 hydrocarbyl group, 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. 
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 colloids which are 75 .ANG. to 500 .ANG. particles of 
alkali and alkaline earth carbonates. These colloids are stabilized by 
other small molecule detergents comprising a polar head with long 
hydrophobic tail, with the polar head comprising a salt of an organic acid 
compound. The salts may contain a substantially stoichiometric amount of 
the metal in which they are usually described as normal or neutral salts, 
and would typically have a total base number (TBN), as may be measured by 
ASTM D-2896 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 acid gas such as carbon dioxide. When small molecule 
detergents are added to stabilize the colloid, the resulting overbased 
detergent comprises neutralized detergent as the outer layer of a metal 
base (e.g., carbonate) micelle. Such overbased detergents may have a TBN 
of 150 or greater, and typically from 250 to 450 or more. 
Detergents that may be used include oil-soluble neutral and 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 neutral and overbased calcium 
sulfonates having TBN of from 20 to 450, and neutral and overbased calcium 
phenates and sulfurized phenates having TBN of from 50 to 450. 
Oxidation inhibitors or antioxidants reduce the tendency of base stocks to 
deteriorate in service which deterioration can be evidenced by the 
products of oxidation such as sludge and 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, arylamines, 
calcium nonylphenol sulfide, ashless 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. 
Friction modifiers may be included to improve fuel economy. Oil-soluble 
alkoxylated mono- and di-amines are well known to improve boundary layer 
lubrication. The amines may be used as such or in the form of an adduct or 
reaction product with a boron compound such as a boric oxide, boron 
halide, metaborate, boric acid or a mono-, di- or tri-alkyl borate. 
Other friction modifiers are known. Among these are esters formed by 
reacting carboxylic acids and anhydrides with alkanols. Other conventional 
friction modifiers generally consist of a polar terminal group (e.g. 
carboxyl or hydroxyl) covalently bonded to an oleophillic hydrocarbon 
chain. Esters of carboxylic acids and anhydrides with alkanols are 
described in U.S. Pat. No. 4,702,850. Examples of other conventional 
friction modifiers are described by M. Belzer in the "Journal of 
Tribology" (1992), Vol. 114, pp. 675-682 and M. Belzer and S. Jahanmir in 
"Lubrication Science" (1988), Vol. 1, pp. 3-26. One such example is 
organo-metallic molybdenum. 
Rust inhibitors selected from the group consisting of nonionic 
polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and 
anionic alkyl sulfonic acids may be used. 
Copper and lead bearing corrosion inhibitors may be used, but are typically 
not required with the formulation of the present invention. Typically such 
compounds are the thiadiazole polysulfides containing from 5 to 50 carbon 
atoms, their derivatives and polymers thereof. Derivatives of 1,3,4 
thiadiazoles such as those described in U.S. Pat. Nos. 2,719,125; 
2,719,126; and 3,087,932; are typical. Other similar materials are 
described in U.S. Pat. Nos. 3,821,236; 3,904,537; 4,097,387; 4,107,059; 
4,136,043; 4,188,299; and 4,193,882. Other additives are the thio and 
polythio sulfenamides of thiadiazoles such as those described in UK. 
Patent Specification No. 1,560,830. Benzotriazoles derivatives also fall 
within this class of additives. When these compounds are included in the 
lubricating composition, they are preferably present in an amount not 
exceeding 0.2 wt % active ingredient. 
A small amount of a demulsifying component may be used. A preferred 
demulsifying component is described in EP 330,522. It is obtained by 
reacting an alkylene oxide with an adduct obtained by reacting a 
bis-epoxide with a polyhydric alcohol. The demulsifier should be used at a 
level not exceeding 0.1 mass % active ingredient. A treat rate of 0.001 to 
0.05 mass % active ingredient is convenient. 
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, polyalkylmethacrylates and the like. 
Foam control can be provided by many compounds including 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 does not 
require further elaboration. 
Catapult Oils 
Catapults are instruments used on aircraft carriers at sea to eject the 
aircraft off of the carrier. The inventive viscosity modifier composition 
can be used as part of an additive package in the formulation of catapult 
oils together with selected lubricant additives. The preferred catapult 
oil is typically formulated using the viscosity modifier composition 
formed according to the present invention together with other conventional 
catapult oil additives. The additives listed below are typically used in 
such amounts so as to provide their normal attendant functions. The 
additive package may further include, but is not limited to corrosion 
inhibitors, oxidation inhibitors, extreme pressure agents, color 
stabilizers, detergents and rust inhibitors, antifoaming agents, anti-wear 
agents, and friction modifiers. These additives are disclosed in Klamann, 
"Lubricants and Related Products", Verlag Chemie, Deerfield Beach, Fla., 
1984, which is corporated herein by reference. 
The catapult oil according to the present invention can employ typically 
bout 90 to 99% base stock, with the remainder comprising an additive 
package. 
Hydraulic Fluids 
The inventive viscosity modifier can be used in an additive package for the 
formulation of hydraulic fluids together with other selected lubricant 
additives. The preferred hydraulic fluids are typically formulated using 
the viscosity modifier composition formed according to the present 
invention together with other conventional hydraulic fluid additives. The 
additives listed below are typically used in such amounts so as to provide 
their normal attendant functions. These other additives may further 
include, but are not limited to, corrosion inhibitors, boundary 
lubrication agents, demulsifiers, pour point depressants, and antifoaming 
agents. 
The hydraulic fluid according to the present invention can employ typically 
about 90 to 99% base stock, with the remainder comprising an additive 
package. 
Other additives are disclosed in U.S. Pat. No. 4,783,274 (Jokinen et al.), 
which issued on Nov. 8, 1988, and which is incorporated herein by 
reference. 
Drilling Fluids 
The inventive viscosity modifier can be used in an additive package in the 
formulation of drilling fluids together with other selected lubricant 
additives. The preferred drilling fluids are typically formulated using 
the viscosity modifier composition formed according to the present 
invention together with other conventional drilling fluid additives. The 
additives listed below are typically used in such amounts so as to provide 
their normal attendant functions. The additive package may further 
include, but is not limited to, corrosion inhibitors, wetting agents, 
water loss improving agents, bactericides, and drill bit lubricants. 
The drilling fluid according to the present invention can employ typically 
about 60 to 90% base stock and about 5 to 25% solvent, with the remainder 
comprising an additive package. See U.S. Pat. No. 4,382,002 (Walker et 
al), which issued on May 3, 1983, and which is incorporated herein by 
reference. 
Suitable hydrocarbon solvents include: mineral oils, particularly those 
paraffin base oils of good oxidation stability with a boiling range of 
from 200-400.degree. C. such as Mentor 28.RTM., sold by Exxon Chemical 
Americas, Houston, Tex.; diesel and gas oils; and heavy aromatic naphtha. 
Turbine Oils 
The viscosity modifier of the present invention can be used in an additive 
package in the formulation of turbine oils together with other selected 
lubricant additives. The preferred turbine oil is typically formulated 
using the viscosity modifier formed according to the present invention 
together with other conventional turbine oil additives. The additives 
listed below are typically used in such amounts so as to provide their 
normal attendant functions. The additive package may further include, but 
is not limited to, corrosion inhibitors, oxidation inhibitors, thickeners, 
dispersants, anti-emulsifying agents, color stabilizers, detergents and 
rust inhibitors, and pour point depressants. 
The turbine oil according to the present invention can employ typically 
about 65 to 75% base stock and about 5 to 30% solvent, with the remainder 
comprising an additive package, typically in the range between about 0.01 
to about 5.0 weight percent each, based on the total weight of the 
composition. 
Compressor Oils 
The viscosity modifier of the present invention can be used in an additive 
package in the formulation of compressor oils together with other 
lubricant additives. The preferred compressor oil is typically formulated 
using the viscosity modifier formed according to the present invention 
together with other conventional compressor oil additives. The additives 
listed below are typically used in such amounts so as to provide their 
normal attendant functions. The additive package may further include, but 
is not limited to, oxidation inhibitors, additive solubilizers, rust 
inhibitors/metal passivators, demulsifying agents, and anti-wear agents. 
Polymerization 
The process in accordance with the present invention forms copolymers by 
polymerization of a reaction mixture comprising a catalyst, ethylene and 
at least one additional .alpha.-olefin monomer. Polymerization in the 
presence of an inert diluent is preferred. Suitable diluents are described 
in U.S. Pat. No. 4,882,406, the teachings of which are incorporated herein 
by reference. 
The copolymerization is carried out in a mix-free reactor system, which is 
one in which substantially no mixing occurs between portions of the 
reaction mixture that contain polymer chains initiated at different times. 
Suitable reactors are disclosed in U.S. Pat. Nos. 4,959,436 and 4,882,406, 
both of which are incorporated herein by reference. The use of a tubular 
reactor is preferred. Additional reaction considerations are also 
disclosed in these references. 
To obtain the desired B block in the polymer it is necessary to add 
additional reactants (monomer of the at least one .alpha.-olefin) either 
at some point or points along the length of the tubular reactor, or at 
different times during the course of polymerization in a batch reactor, or 
at various points in a train of continuous flow stirred reactors, which 
can be used to mimic a tubular reactor. However, it is preferable to add 
essentially all of the catalyst at the inlet of a tubular reactor or at 
the onset of batch reactor operation. Since the tubular reactor is the 
preferred system for carrying out the processes in accordance with the 
preferred embodiment, the illustrative descriptions and examples that 
follow are drawn to that system, but will readily apply to other reactor 
systems. As will be further readily apparent to one of ordinary skill in 
the art having benefit of the present disclosure, more than one reactor 
could be used, either in parallel or in series, with multiple monomer 
feeds to vary intramolecular composition. 
Any known diluent for the reaction mixture that is effective for the 
purpose can be used in conducting the polymerization in accordance with 
the present invention. For example, suitable diluents would be 
hydrocarbons such as aliphatic, cycloaliphatic and aromatic hydrocarbons, 
or halogenated versions of such hydrocarbons. The preferred diluents are 
C.sub.12 or lower, straight or branched chain, saturated hydrocarbons, 
C.sub.5 to C.sub.9 saturated alicyclic or aromatic hydrocarbons or C.sub.2 
to C.sub.6 halogenated hydrocarbons. Most preferred are C.sub.12 or lower, 
straight or branched chain, saturated hydrocarbons, particularly hexane. 
Non-limiting illustrative examples of diluents are hexane, methyl pentane, 
heptane, cyclopentane, cyclohexane, cycloheptane, methyl cyclopentane, 
methyl cyclohexane, isooctane, benzene, toluene, xylene, chloroform, 
chlorobenzenes, tetrachloroethylene, dichloroethane and trichloroethane. 
Under pressurized conditions, butane and pentane are also suitable 
diluents. 
The polyethene A block is insoluble in hydrocarbons at temperatures below 
about 60.degree. C. and thus is insoluble at normal polymerization 
temperatures. This can be determined experimentally by observing the 
polymerization in a glass reactor. The reactor contents become opaque to 
visible light as the A block is polymerized and crystalizes from solution 
and the colloidally sized particles cause scattering. After the 
hydrocarbon-soluble B block begins to grow, the A block is partially 
solublized and a dispersion forms that can be stable for days at 
20.degree. C. If the concentration of the A block in the polymerizing 
medium is too high for the temperature at which the polymerization is 
run,severe precipitation can occur wherein mass transfer problems arise 
which tend to broaden the molecular weight distribution of the product and 
lower the yield of the polymer per amount of polymerization catalyst used. 
Concentration and temperature must be optimized to maximize production 
rate and minimize the breadth of the molecular weight distribution, which 
leads to good TE-SSI behavior. 
Catalyst systems to be used in carrying out the processes in accordance 
with the present invention may be Ziegler catalysts, which may typically 
include: (a) a compound of a transition metal, i.e., a metal of Groups 
I-B, III-B, IVB, VB, VIB, VIIB and VIII of the Periodic Table, and (b) an 
organometal compound of a metal of Groups I-A, II-A, II-B and III-A of the 
Periodic Table. 
The preferred catalyst system in practicing processes in accordance with 
the present invention are described, for example, in U.S. Pat. Nos. 
4,882,406 and 4,900,461, the contents of which are incorporated herein by 
reference. This preferred catalyst system comprises hydrocarbon soluble 
vanadium compounds in which the vanadium valence is 3 to 5 and 
organo-aluminum compounds. At least one of the vanadium compounds or 
organo-aluminum compounds must also contain a valence-bonded halogen. 
Vanadium compounds useful in the practicing processes in accordance with 
the present invention include: 
##STR1## 
EQU VCl.sub.x (COOR).sub.3-x (2) 
where x=0 to 3 and R=a hydrocarbon radical; 
##STR2## 
where AcAc=acetyl acetone; and where x=1 or 2; and 
EQU VCl.sub.3.nB 
wherein n=2 to 3 and B=a Lewis base capable of making hydrocarbon soluble 
complexes with VCl.sub.3 such as tetrahydrofuran, 2-methyl-tetrahydrofuran 
and dimethyl pyridine. In Formulas (1) and (2) above, R preferably 
represents C.sub.1 to C.sub.10 aliphatic, alicyclic, or aromatic 
hydrocarbon radical such as ethyl (Et), phenyl, isopropyl, butyl, propyl, 
n-butyl, i-butyl, t-butyl, hexyl, cyclohexyl, octyl, naphthyl, etc. 
Non-limiting illustrative examples of formulas (1) and (2) compounds are 
vanadyl trihalides, alkoxy halides and alkoxides such as VOCl.sub.3, 
VOCl.sub.2 (OBu) where Bu=butyl, VO(OC.sub.2 H.sub.5).sub.3, and vanadium 
dichloro hexanoate. The most preferred vanadium compounds are VCl.sub.4, 
VOCl.sub.3 and VOCl.sub.2 (OR). 
As already noted, the co-catalyst is preferably an organoaluminum compound. 
In terms of chemical formulas, these compounds could be AlR.sub.3, 
AlR.sub.2 X, AlR'RX, Al.sub.2 R.sub.3 X.sub.3, AlRX.sub.2, Al(OR')R.sub.2, 
R.sub.2 Al-O-AlR.sub.2 and methyl alumoxane, wherein R and R' represent 
hydrocarbon radicals, R and R' being the same or different, and wherein X 
is a halogen selected from the group consisting of bromine, chlorine, and 
iodine, with chlorine being preferred. The most preferred organoaluminum 
compound for use with a vanadium compound is an aluminum alkyl 
sesquichloride such as Al.sub.2 Et.sub.3 Cl.sub.3 or Al.sub.2 (iBu).sub.3 
Cl.sub.3. The catalyst and its effects on the polymerization are disclosed 
in U.S. Pat. No. 4,882,406, the subject matter of which was previously 
incorporated herein by reference. 
Chain transfer reactions during tubular reactor polymerization can broaden 
molecular weight distribution and cause the formation of undesirable 
species such as A-only polymer or B-only polymer rather than the desired 
AB block copolymers of the present invention. It is desirable to operate 
at low temperatures, and in the absence of hydrogen to avoid hydrogen, 
monomer, or aluminum alkyl transfer reactions. U.S. Pat. No. 4,882,406, 
previously incorporated by reference, discloses chain transfer reactions. 
Molecular weight distribution and percent of block copolymer in the final 
product are also affected by catalyst deactivation during the course of 
polymerization which leads to termination of growing chains. Early chain 
termination will reduce the yield of the desired block copolymers. 
Deactivation can be reduced by using the shortest residence time and the 
lowest temperature in the reactor that will produce the desired monomer 
conversions. 
Gel Permeation Chromatography (GPC) and several analytical techniques are 
used to characterize the polymer and its performance. These techniques 
have been described in several publications, notably U.S. Pat. No. 
4,989,436, which is incorporated herein by reference. Molecular weight and 
composition measurements are described in G. Ver Strate, C. Cozewith, S. 
Ju, Macromolecules, 21, 3360 (1988). The variety of other techniques used 
are soundly based in polymer structure characterization as described in 
"Structure Characterization" The Science and Technology of Elastomers, F. 
Eirich, editor, Academic Press, Revised Edition 1995, Chapter 3 by G. Ver 
Strate. Differential Scanning Calorimetry (DSC) is used to characterize 
the block copolymers described herein. The standard protocol for these 
analysis is to load the calorimeter at 20.degree. C. with a specimen free 
of molding strains and which has been stored at 20.degree. C. for more 
than 48 hours, to cool the sample to -100.degree. C., scan to 180.degree. 
C. at 10.degree. C./min., cool to -100.degree. C., and immediately re-run 
the scan. T.sub.g, T.sub.m and heat of fusion are evaluated for both 
scans. In general, only crystallinity from the polyethene A block is 
present in the second scan. Heats of fusion for both the A and B blocks 
can be evaluated by integrating the endotherms with appropriate 
extrapolation to construct baselines using methods known to those skilled 
in the art. The term "melting point", as used herein, refers to the 
temperature of maximum departure of the melting endotherm from the 
extrapolated baseline. Termination of melting may occur at a temperature 
20.degree. C. higher. 
Polymerization in accordance with the preferred embodiments should be 
conducted in such a manner and under conditions sufficient to initiate 
propagation of essentially all polymer chains simultaneously. This can be 
accomplished by utilizing the process steps and conditions described in 
U.S. Pat. No. 4,959,436, incorporated herein by reference. The temperature 
of the reaction mixture should also be kept within certain limits. The 
temperature at the reactor inlet should be high enough to provide 
complete, rapid chain initiation at the start of the polymerization 
reaction. The length of time the reaction mixture spends at high 
temperature must be short enough to minimize the amount of undesirable 
chain transfer and catalyst deactivation reactions. Control of the 
reaction temperature in light of the fact that the reaction is exothermic, 
is disclosed in U.S. Pat. No. 4,959,436, which was previously incorporated 
herein by reference. Residence time in the reactor can vary over a wide 
range. The minimum could be as low as 0.5 seconds. A preferred minimum is 
about 2 seconds. The maximum can be as high as about 100 seconds. A 
preferred maximum is about 20 seconds. The residence time is dictated by 
the inherent reaction rates for the catalyst components that are used. 
When a tubular reactor is used, the rate of flow of the reaction mixture 
through the reactor should be high enough to provide good mixing of the 
reactants in the radial direction and minimize mixing in the axial 
direction. Good radial mixing promotes homogeneous temperature and 
polymerization rates at all points in the reactor cross-section. Radial 
temperature gradients may tend to broaden the molecular weight 
distribution of the copolymer since the polymerization rate is faster in 
the high temperature regions. This problem can be overcome to some extent 
through the use of radial mixing devices such as static mixers (e.g., 
those produced by the Kenics Corporation). 
Prior to the present invention, it has not been possible to efficiently 
form a high melting polyethylene (PE) A block, insoluble in the 
polymerization diluent, and subsequently attach an ethylene-propylene (EP) 
B block. Various attempts have been made to form such polymers by first 
polymerizing a soluble polypropylene or ethylene-propylene B block, and 
then attaching a polyethylene A block. Such a process can only be 
practiced, however, when the catalyst is capable of consuming essentially 
all of the propene present in the reactor prior to the introduction of the 
ethene. Otherwise, the PE block will contain too much propene. Such 
polymerizations can only be conducted at extremely low temperatures, e.g. 
-60.degree. C., as described, for example by Doi et al. in "Advances in 
Polymer Science", 73, 201 (1996), which renders the process unsuitable for 
commercial production purposes, or by using metallocene catalysts that are 
prohibitively expensive for growing one molecule per metal atom, as 
described in WO9112-285A to Turner et al, both of which are incorporated 
herein by reference. 
The amount of EP fragments, without an attached PE block will generally be 
reduced as the reactor temperature is lowered because the EP is formed 
primarily by transfer reactions, which occur above 40.degree. C., 
depending upon the particular catalyst used. Conversely, the amount of PE 
fragments without an attached EP block is reduced as the temperature is 
raised. Although applicants do not wish to be bound by any particular 
theory, the decrease in free PE segments is thought to be due to increased 
A block solubility at higher temperature, which causes crystallization to 
slow and polymerization to be less impeded by mass transfer limitations. 
Thus, there will be an optimal temperature range over which the yield of 
the desired PE-EP block copolymer is maximized. 
The product can be extracted with a suitable solvent at about 45-60.degree. 
C. to determine the portion that contains no PE block. Once extracted, the 
polymer will still contain a fraction of low molecular weight PE 
unattached to EP. This fraction can be determined by performing a GPC 
expeiment with infrared (IR) compositional analysis of the effluent, as 
will be descibed in Example 4, infra. This fraction will tend to decrease 
as a percentage of the polymer as the monomer to diluent ratio is 
decreased in the reactor feed, whereby the PE concentration is decreased. 
This fraction will increase as the temperature of the diluent is decreased 
below about 10.degree. C., at the start of polymerization. Thus, high 
temperatures favor lower free PE fragments and lower temperatures favor 
lower free EP fragments. 
The preferred mode of cooling the reactor, in the process of the invention, 
is to use prechilled feeds and allow the reactor to operate adiabatically. 
Using this cooling mode, the temperature profile along the length of the 
reactor depends strongly on the polymerization rate, polymer 
concentration, and the location of the sidestream monomer feeds. Since 
reactor temperature depends on polymer concentration, the cement 
concentration (the concentration of polymer in the polymerization solvent 
or diluent) needs to be maintained at a level sufficiently low to cause 
the reactor to be operable in the optimum temperature range. For a 
10.degree. C. mainstream feed temperature, the preferred final block 
copolymer concentration should be between 2 and 7 wt %, preferably between 
3 and 6 wt % and most preferably between 3.5 and 5 wt %. Sidestream feeds 
can be added at lower temperatures, e.g. -40.degree. C., which 
beneficially maintains the reactor outlet temperature below about 
50.degree. C. 
Product yield is also dependent on the residence time at which side feeds 
are injected into the reactor. If the first side stream used to initiate 
growth of the EP block is injected too soon, the PE block will not attain 
its full growth and will be shorter than desired. However, because the 
catalyst system used in the process of the invention loses activity 
rapidly, in the case in which the first side stream is injected too late, 
the amount of free PE fragments in the polymer increases to unacceptable 
levels. The time at which additional side streams are added is also 
important since the reactor temperature is highest at the end of the 
reactor, and the addition of sidestreams close to the reactor exit 
therefore promotes the formation of EP fragments through chain transfer 
reactions. 
Preferred residence times will depend on catalyst components, polymer 
concentration and reactor temperature, and changes in reactor conditions 
that increase the polymerization rate will shorten the reactor residence 
times needed for any given result. For example, experimentation determined 
that to make a PE-EP block copolymer with 20 wt. % PE block at a reactor 
outlet temperature of about 30.degree. C., the preferred residence time in 
the reactor was about 8 secs. at 1% polymer concentration, about 5 secs. 
at 3% polymer concentration, and about 2.5 secs. at 5% polymer 
concentration. 
Because of the wide range of possible reaction conditions in terms of 
residence times, feed temperatures, reactor temperatures, and monomer 
concentrations, and because of complex interactions among these parameters 
in terms of their effect on the polymer, it is not possible to specify a 
most preferred mode of reactor operation that will apply to all possible 
catalyst components, polymer compositions, block structures and polymer 
molecular weights within the scope of the invention. However, for 
adiabatic operation of a tubular reactor, in the practice of the present 
invention, the following procedures are preferably observed: 
(a) the first side stream is preferably added to the reactor as soon as the 
ethylene conversion in the main feed reaches about 85-90%; 
(b) the reaction should preferably be ended by injecting a quench (short 
stop) into the reactor at the point at which the reactor outlet 
temperature has reached 75-98% of the maximum outlet temperature, defined 
as the temperature at a residence time at which the catalyst is 95-100% 
deactivated and polymerization has essentially ceased; 
(c) the final side stream should preferably be added to the reactor at a 
residence time that is about 25-60% of the total residence time, and as 
dictated by the percent of catalyst remaining active (at least 60% of the 
catalyst should be active); 
(d) the main feed temperature should preferably exceed -5.degree. C.; and 
(e) the maximum outlet temperature should preferably be less than 
50.degree. C. 
The reactor residence times corresponding to the first feed injection point 
and the quench injection point depend on the details of the reactor 
conditions. However, these times can be determined experimentally by 
observing the temperatures in the reactor, as a function of reactor 
length. As an example, for reactor operation at commercially attractive 
conditions of 4-7% polymer concentration, and with VCl.sub.4 ethyl 
aluminum sesquichloride as catalyst, the residence time at which the first 
feed is injected is preferably in the range of 0.15 to 0.45 seconds, and 
the total residence time is preferably in the range of 1-30 seconds, most 
preferably 2-10 seconds. 
The amount of propene monomer, and the ratio thereof to to the amount of 
ethene, in the main feed, affects the solubility of the A block during 
polymerization. Too little propene, in the main feed, results in a highly 
crystalline and insoluble A block and increases the propensity of the A 
block to precipitate from solution. In addition, a greater amount of 
propene in the main feed provides a resulting polymer that is more easily 
dissolved in oil. An excess of propene, in the main feed, lowers the the 
melting point of the A block causing the A block to have insufficient 
crystallinity during recovery of the polymer from the polymerization 
diluent. This causes the polymer to agglomerate and plug the flash drums 
and slurry strippers. 
In general, for polymer made with the aforementioned vanadium catalysts, 
the melting point (T.sub.m) of a pure (no comonomer) PE block, with no B 
block attached, is about 133.degree. C. When the B block is attached, the 
T.sub.m is lowered about 6 to 8.degree. C. Further lowering of the T.sub.m 
occurs as the propene content of the A block is increased, in an amount 
corresponding to the formula: 
EQU T.sub.m =126.7.+-.1.4-1.84.+-.0.36.times.(weight % propene in A block); 
for A-B block polymers. This equation defines the lower dashed line in FIG. 
1 of this application, in which the intercept on the temperature axis is 
126.7.+-.1.4.degree. C., and the slope is 1.84.+-.36.degree. C. per wt. % 
propene. 
A blocks with melting points in the range of 110-120.degree. C., which 
corresponds to a 3 to 6% propene content, are preferred. In general, the 
instantaneous composition of the A block being polymerized varies between 
the reactor inlet and the position of the first side stream where the B 
block begins to grow. Ethene reacts faster than propene. Therefore, the A 
block becomes more propene rich as the instantaneous ratio of propene to 
ethene increases along the length of the tubular reactor and the highest 
melting portion of the A block forms first. If a more uniform composition 
is desired, an additional ethene feed can be added as a sidestream to 
adjust the A block composition. However, an increase in propene content 
toward the end of the A block increases the solubility of the block, and 
better facilitates the addition of the B block. 
For the mix-free reactor to operate properly, the vanadium and aluminum 
alkylhalide catalyst should be premixed as described in U.S. Pat. No. 
4,959,436, incorporated herein by reference. The premixing time and 
temperature can be fixed independent of the main feed. It has been found 
that, with catalyst concentrations in the range of 0.002 to 0.02 lbs 
VCl.sub.4 /lb. hexane at 15 to 23.degree. C., an Al/V ratio of 8, and a 
premix time of 6 to 8 seconds, is near optimal for maximizing 
instantaneous initiation and minimizing over-reduction of the VCl.sub.4 
with resultant loss of catalyst activity. 
During polymerization, the premixing process is optimized by observing the 
adiabatic temperature rise in the first few tenths of a second downstream 
of the catalyst-main feed mixing point. The fastest rise in temperature is 
preferable for a given total catalyst feed. The molecular weight 
distribution (MWD) of the product polymer should also be monitored. With 
all other variables being equal, the narrowest MWD will be obtained with 
the fastest rise in temperature. Catalyst component and solvent purity can 
affect optimum conditions, and should therefore be continuously monitored. 
Under-premixing causes A blocks of insufficient length and free B blocks 
because the chains initiate too far down the reactor. Over-premixing 
reduces product yield per weight of catalyst used. 
The propene/ethene weight concentration ratio in the sidestream feed is 
determined by the desired B block composition. Higher B block ethene 
content requires a lower ratio. It is preferred to have as high a B block 
ethene content as possible in order to obtain the optimal TE-SSI 
performance. In general, too low a propene/ethene ratio leads to the 
formation of polymer fouling on the surface of the reactor surrounding the 
sidestream feed inlets. Too low a ratio results in unacceptable fouling 
rates. A ratio of above 5 leads to an insufficient ethene content in the B 
block and may also promote chain transfer reactions leading to formation 
of free B blocks. Generally, the first sidestream feed contains a higher 
propene/ethene ratio in comparison to subsequent feeds. This higher ratio 
is maintained in order to cause a sharp drop in the instantaneous 
composition of the polymer being made, from the high ethene content of the 
A block, to promote polymer solubility. This is most important when ethene 
conversion in the PE block polymerization is at the low end of the 
disclosed range of 75 to 98%. 
The number of sidestreams is determined by the intra-molecular composition, 
and propene monomer conversion (consumption) that is desired. Because 
ethene polymerizes faster than propene, it is possible to obtain in excess 
of 95% ethene conversion where propene conversion is only 15%. If all the 
sidestream monomers were to be added as a single feed, the ethene would 
polymerize with itself, to the exclusion of propene. Ethene-ended chains 
incorporate propene much more effectively than propene-ended chains. Thus, 
propene is best incorporated when the ethene is added in several 
sidestreams. 
In general, the sidestream feed temperature is maintained as low as 
possible consistent with polymer solubility and the available 
refrigeration capacity. Low sidestream feed temperatures help keep the 
reactor outlet temperature below the desired 50.degree. C. upper limit. 
High reactor temperatures favor transfer reactions and catalyst 
termination reactions. These, in turn, produce free B blocks and A blocks 
attached to B blocks of insufficient length. These species are 
undesireable for the reasons stated above. Specifically, free A blocks are 
insoluble in oil, free B blocks contribute to poor low temperature 
properties and both broaden the MWD and reduce TE-SSI performance. 
When proper reaction conditions are not maintained, the resulting block 
polymers contain significant amounts of free A and/or B block. The amount 
of these "impurities" can be determined by extraction with cyclohexane at 
45-60.degree. C., to remove free B block, and by subsequent analysis using 
standard GPC-FTIR to detect free A block. In the block polymers of the 
present invention, the amount of free B block is preferably below 15% of 
the total weight of the polymer, and the amount of free A block is 
preferably below 10% of the total weight of the polymer. Free A blocks 
produce sediment and haze in the oil. Free B blocks lower the TE for a 
given SSI and can contribute to poor low temperature properties because 
the absence of an A block allows the molecule, when in solution, to 
interact with waxes in the oil, at low temperatures. 
Polymer Recovery 
Following polymerization, the novel block copolymers of the present 
invention can be recovered from the diluent by any of the methods well 
known to those of ordinary skill in the art. A typical finishing process 
for ethene-propylene elastomeric copolymers is to first remove catalyst 
residues from the solution by extraction with water followed by separation 
of the water phase containing the catalyst residues. The polymer and 
diluent is then heated to flash off most of the diluent and unreacted 
monomers, and finally, the copolymer is recovered by either dewatering or 
devolatizing extrusion, depending upon the type of flashing process 
employed. Steam stripping is commonly used to flash off the diluent and 
monomers. In this process, the polymer and diluent is injected into an 
agitated drum of hot water maintained at a temperature above the boiling 
point of the diluent, and the copolymer precipitates into the water to 
form a slurry of wet particles, typically measuring 0.125 to 1.0 inches in 
size. 
Because of the high temperature in the stripper drums, the elastomeric 
copolymer particles tend to agglomerate and foul the drum, especially when 
the molecular weight is low. It is particularly difficult to form a 
non-agglomerating slurry when the Mooney viscosity (measured at (1+4) and 
125.degree. C.) is less than about 15. This constraint places a lower 
limit on the molecular weight of the preferred copolymer products that can 
be produced in an ethylene-propylene elastomer manufacturing plant. 
It is highly desireable to produce polymers with a Mooney viscosity of less 
than 15 in order to obtain low SSI values. It was thought that such 
polymers would be very difficult, or impractical, to recover by steam 
stripping. Surprisingly, however, it was found that the presence of the PE 
block in the polymer imparts residual crystallinity to the polymer even at 
steam stripping temperatures. Consequently, the polymers behave in the 
steam stripper as if they had a much higher viscosity than a melted 
polymer of the same molecular weight, and it is possible to slurry 
polymers with Mooney viscosities as low as 5 as measured at 150.degree. C. 
(which corresponds to a Mooney viscosity of about 8 at 125.degree. C.), at 
steam stripping temperatures, even above 110.degree. C. For low Mooney 
viscosity block copolymer products, the maximum steam stripping 
temperature that can be used without particle precipitation problems is 
related to the melting point of the PE block, which is a function of 
propylene content, as was described above. In general, the maximum 
stripping temperature should be 3 to 8.degree. C. less than the T.sub.m of 
the PE block. 
EXAMPLES 
In the following examples it is demonstrated that there are clear bounds on 
the PE block content and Tm, fixed on the low end by polymer recovery 
operations in manufacturing and on the high end by solubility of the 
mechanically degraded polymer in oil at 100 C. The kv of the fully 
dissolved polymer must be measured at 100 C. to classify the oil by grade 
and to test it's susceptibility to mechanochemical degradation. 
There are also bounds on the process conditions to make the polymer. Those 
conditions which may be used to prepare prior art narrow MWD mix free 
reactor polymers must be altered due to the insolubility of the PE block 
in the polymerization diluent. Temperature and cement concentration must 
be controlled to minimize the amount of free A and B block that is formed. 
Comparative Example 1a 
Samples of poly-co(ethene-propene) (EP) polymers of two different molecular 
weights are prepared as described in Example 4 of U.S. Pat. No. 4,900,461. 
The manufacture includes catalyst premixing, polymerization in hexane 
diluent, deashing of the polymer with a water wash, recovery of the 
polymer from the diluent by steam distillation and extrusion drying to 
remove residual water, hexane and other volatiles. These polymers can be 
purchased from Exxon Chemical Co. as Vistalon 878 and Vistalon 91-9. 
The polymers were formulated to produce 0.7 and 1.1 weight percent 
solutions in a basestock, ENJ 102, which basestock has a 100 C kv of 6.05 
cStokes. 
These solutions were tested for polymer mechanochemical stability by 
subjecting them to a Kurt Orbahn shear stability index (SSI) test. Results 
are presented in Table 1a. 
The polymers were also formulated into 10W40 SH passenger car lubricating 
oil compositions. The formulation is as follows (in wt. %): VM concentrate 
PTN8452 11.2, Exxon 100N LP 25, Exxon 150N RP 51.7, Paranox 5002 12.1. 
The pour points (PP), mini rotary viscometer (MRV) viscosities measured in 
the TP1 cycle, cold cranking simulator (CCS), viscosity index (VI) and 
high temperature high shear viscosity (HTHS), were similarly measured with 
the results given in Table 1a. 
TABLE 1A 
__________________________________________________________________________ 
Properties of Commercial Mix Free Reactor Poly(ethene-co-propene) 
Polymers 
TP1 CCS 
Mooney 
TE SSI 
Mw Tm Wt % 
PP C 
cP cP HTHS 
Viscosity 
ENJ 
% K C Ethene 
Final 
-20.degree. C. 
-20.degree. C. 
cP 150.degree. C. 
VI 
Sample 
Polymer 
102 
&gt;&gt;&gt; 
Polymer 
&gt;&gt;&gt; 
&gt;&gt;&gt; Oil &gt;&gt; 
&gt;&gt;&gt; &gt;&gt;&gt; &gt;&gt;&gt; &gt;&gt;&gt; 
__________________________________________________________________________ 
878 55 3.3 
50 180 45 54 -30 8,900 
2960 
3.7 140 
91-9 
20 2.8 
37 140 45 53 -30 8,970 
2930 
3.8 140 
__________________________________________________________________________ 
The performance of these EP polymers as lubricating oil viscosity modifiers 
with regard to TE-SSI and low temperature properties vs manufacturing cost 
is believed to the best for any VM available prior to the present 
invention. 
Comparative Example 1b 
EP polymers that are made in conventional backmixed reactors are less 
effective compared to those of Example 1. They do not have as good a 
TE-SSI behavior for their molecular weight and average ethene content and 
the low temperature properties are not as good. 
ATONE 8900 and PAPATONE 715, are products of Exxon Chemical, are 
commercially available and are made in such backmixed reactors. The former 
has a higher ethene content and outperfoms the latter as a viscosity 
modifier in TE-SSI, but is inferior with respect to pour point. 
Another commercially available family of polymers are the Shellvis 200-300 
grades. These are hydrogenated star branched polyisoprenes. 
Data for comparative purposes for these polymers is presented in Table 1b. 
The formulations are as follows; 
For 15W40 
SV251(13.5% AI) 5.41 wt. %, Mobil 100NS 59.4 wt %, Mobil 300NS 17.9 wt. %, 
ESN 130 1.4 wt. %, AFLOW 387 0.22 wt. %, ANOX 3381 15.6 wt. %. With 
ATONE 8900, same as above, except ATONE 8900 0.67 wt. % (pure 
polymer), ESN 130 6.1 wt. %, AFLOW 387 0.43 wt. % 
For 20W50 
SV251(13.5% AI) 5.41 wt. %, Mobil 150NS 5.0 wt %, Mobil 300NS 72.6 wt. %, 
ESN 130 1.2 wt. %, AFLOW 387 0.22 wt. %, ANOX 3381 15.6 wt. %. With 
ATONE 8900, same as above, except ATONE 8900 0.64 wt. % (pure 
polymer), ESN 130 5.84 wt. %, AFLOW 387 0.43 wt. % 
For 10W30 
SV251(13.5% AI) 5.04 wt. %, Mobil 100NS 44.9 wt %, Mobil 300NS 32.8 wt. %, 
ESN 130 1.5 wt. %, AFLOW 387 0.22 wt. %, ANOX 3381 15.6 wt. %. With 
ATONE 8900, same as above, except ATONE 8900 0.64 wt. % (pure 
polymer), ESN 130 5.8 wt. %, AFLOW 387 0.43 wt. % 
All components are commercially available products of either Mobil or Exxon 
Corporations. 
TABLE 1B 
__________________________________________________________________________ 
PERFORMANCE OF PTN 8900 AND SV 251 
__________________________________________________________________________ 
Fixed BS Ratios: Mobil 150NS:Mobil300NS:ESN130 = 71.2:21.5:7.3 
15W40 TE Net VM Typical Te 
VM LOFI/Treat (wt %) 
SSI 
(ENJ102) 
Treat Rate (wt %) 
kv @ 100 C 
CCS (-15 C) 
PP (C) 
TP1 (-20 
Yield 
Hazess 
__________________________________________________________________________ 
SV251** 
PF387/0.22 
8 2.4 0.73 14.19 3280 -27 10460 &lt;35 11 
PF392/0.15 -27 11000 &lt;35 
PTN8900 
PF387/0.43 
24 2 0.67 14.88 3155 -24 8610 &lt;35 11 
PF392/0.3 -30 8190 &lt;35 
__________________________________________________________________________ 
Mobil 100 NS:Mobil 150 NS:ESN130 = 53.7:39.3 
10W30 TE Net VM 
VM LOFI/Treat (wt %) 
SSI 
(ENJ102) 
Treat Rate (wt %) 
kv @ 100 C 
CCS (-15 C) 
PP (C) 
TP1 (-20 
Yield 
Hazess 
__________________________________________________________________________ 
SV251** 
PF387/0.22 
8 2.4 0.68 11.67 3215 -27 10780 &lt;35 9 
PF392/0.15 -21 56600 &gt;105 
PTN8900 
PF387/0.43 
24 2 0.64 11.66 3300 -27 10240 &lt;35 10 
PF392/0.3 -33 10285 &lt;35 
__________________________________________________________________________ 
Mobil 150 NS:Mobil 300 NS:ESN130 = 5.97:87.03:kv @ 100 C (BS + DI) = 
20W50 TE Net VM 
VM LOFI/Treat (wt %) 
SSI 
(ENJ102) 
Treat Rate (wt %) 
kv @ 100 C 
CCS (-15 C) 
PP (C) 
TP1 (-20 
Yield 
Hazess 
__________________________________________________________________________ 
SV251** 
PF387/0.22 
8 2.4 0.73 18.41 4015 -24 11750 &lt;35 10 
PF392/0.15 -24 12370 &lt;35 
PTN8900 
PF387/0.43 
24 2 0.64 18.29 4039 -24 10420 &lt;35 10 
PF392/0.3 -27 10810 &lt;35 
__________________________________________________________________________ 
In the abovetable, haze is measurd using a HACH Turbidimeter (MOdel 
1890000 Ratio Turbidimeter) 
*The kv of (basestocks + DI + LOFI) of the finished oil was estimated fro 
the TE equation, assuming a TE of 2 for PTN8900. 
**SV251 (concentrate form of SV250) was chosen by Isabel MacDonald for 
comparison purposes. 
***SB: Silverson Treatment 
Comparative Example 2 
In this example a polymer similar to those in Comparative Example 1a is 
prepared, except that the middle section of the molecule is made to have 
an average ethene content of 60 to 63 weight % ethene. This sample can be 
found as Example 3-5 in U.S. Pat. No. 4,900,461. With the center section 
of the molecule at lower ethene content than in Example 1a above, the 
intramolecular CD is nearly flat. The polymer is tested in the same 
formulation as in Example 1a. 
TABLE 2 
__________________________________________________________________________ 
Properties of Poor EP Structure Mix Free Reactor Poly(ethene-co-propene) 
Polymers 
CCS 
SSI 
PP TP1 cP 
cP Mw HTHS Tm Wt % 
Sample 
Mooney 
TE 
% C -20.degree. C. 
-20.degree. C. 
K cP VI C Ethene 
__________________________________________________________________________ 
Sample 
55 3.4 
58 -20 
&gt;30 K 
3200 
180 
3.7 140 
&lt;20 
50 
2A 
__________________________________________________________________________ 
It is seen that the PP and TP1 values exceed those acceptable for SH 10W30 
grade oils. The needed exclusion of sections of the polymer chain from 
containing 56-65 wt. % ethene restricts the manufacturer in how the 
product can be made and the product polymer performance is subject to wide 
variation dependent on the wax structure of the particular basestock 
employed. 
Comparative Example 3 
In this example a polymerization such as that used to make the 878 and 909 
polymers of Comparative Example 1a above was run, with the exception that 
adequate catalyst was added to the reactor to lower the molecular weight 
(Mw) to 110K. This polymer has a TE of about 2.5 and a melting point below 
50.degree. C., and a Mooney viscosity at 125.degree. C. of about 15. 
When the polymer cement was steam distilled at 110.degree. C. to remove the 
solvent after polymerization, the polymer agglomerated and plugged the 
steam distillation vessel. It is not possible to manufacture polymer in 
conventional polyco(ethene-propene) manufacturing plants using polymers 
with the intramolecular compositional distribution of Examples 1a, 1b 
above, with a low enough molecular weight or TE to have the SSI be below 
30%. This experiment has been repeatedly run under commercial conditions 
and the minimum molecular weight that can be finished, in terms of Mooney 
viscosity at 125.degree. C. is 15, where TE is about 2.7 and SSI is &gt;35%. 
The tendency for the polymer to agglomerate in a steam distillation 
operation can be measured by the low strain rate (&lt;10.sup.-1 sec.sup.-1) 
bulk viscosity of the polymer at 110.degree. C. Polymers with viscosity 
less than 10.sup.6 poise agglomerate. Various slurry aids and agitation of 
the vessel's contents can be employed to vary this operation boundary 
somewhat, however it is a practical limitation on a steam distillation 
operation where soft buoyant particles must be prevented from 
agglomerating and clogging the processing equipment. 
Example 4 
In this example a series of PE-EP block polymers of differing molecular 
weight, % PE block, EP composition and MWD were made and then tested in 
subsequent examples for the properties measured in the Comparative 
Examples above. 
Experiments were carried out in a tubular reactor of either 1" or 5" 
diameter. A main feed consisting of hexane, ethylene and optionally 
propylene, was prechilled and fed to the reactor inlet. The catalyst 
components were premixed as described in U.S. Pat. No. 4,804,794 and fed 
to the reactor downstream of the main feed inlet, to initiate 
polymerization. Additional feeds of hexane, ethylene, and propylene were 
added along the reactor length through mixing tees to form the EP block of 
the block polymer. Hexane was present in the side stream flows in a 
sufficient amount to dissolve all the monomers. Reactor outlet pressure 
was set high enough to prevent the formation of a vapor phase in the 
reactor. Main feed and side stream feed temperatures could be controlled 
independently and were adjusted to give the desired reactor outlet 
temperature. 
The material exiting the reactor was a polymer dispersion in hexane that 
had the appearance of a glass of milk. After many hours of settling, the 
dispersion separated into a clear hexane phase containing some dissolved 
EP block and a concentrated disperse phase of approximately equal volume. 
Thus, the products of this invention do not form a solution in hexane at 
the conditions in the reactor. 
At a selected point along the reactor, a stream of water was injected to 
kill the catalyst and end the polymerization. Catalyst residues were 
removed from the polymer solution by water extraction. Polymer was then 
recovered from solution by steam precipitation (distillation of the 
solvent and residual monomers) followed by extrusion drying of the wet 
rubber. 
When the reactor and polymer recovery system were at steady state for a 
given set of reactor operating conditions, polymer samples were obtained 
either from the reactor outlet, the steam stripping tank, or the extruder 
outlet, for analysis. Polymer analysis were carried out by the following 
techniques: 
a. Average Ethylene Content 
The same infrared technique as that disclosed in U.S. Pat. No. 4,900,461 
was employed to measure the ethene content of the whole polymers. The ASTM 
methods described there, ASTM D3900-95 (and it's precursors) and ASTM 
D2238, have been modified by recalibration based on a set of standards 
analyzed for ethylene content by C13 NMR. For reference to the previous 
work new and old ethene contents are related as follows: new wt % 
ethene=0.66 (old wt % ethene)+26.9 (high ethene method) and new Wt % 
ethene=1.07 (old wt % ethene)+2.2 (low ethene method). Thus there is an 
upward shift of about 5.7 wt % ethene at 50% ethene. 
b. Mooney Viscosity (ML 1+4): ASTM D 1646-96 
The Mooney viscosity was measure according to ASTM D 1646-96 except that 
the temperature was 150.degree. C. instead of the standard 125.degree. C., 
as the polymer is still crystalline at 125.degree. C. and the viscosity is 
raised by the crystallinity yielding results which do not correlate with 
molecular weight, TE or SSI. 
c. Gel Permeation Chromatography/LALLS (GPC/LALLS) 
Molecular weight and molecular weight distribution were measured by the 
same techniques as disclosed in U.S. Pat. No. 4,900,461. Further 
disclosure of that method was presented in G. Ver Strate, C. Cozewith, S. 
Ju, Macromolecules, 1988, 21 3360, which is incorporated herein as 
reference. Standard conditions are 135.degree. C. using trichlorobenzene 
as solvent. 
As noted in the cited reference various GPC parameters have absolute 
significance in addition to permitting MWD breadths to be compared on a 
relative basis. For purposes of this application the GPC data were 
evaluated using no corrections for spreading, concentration dependence on 
elution time or other effects. The set of four Showdex columns produced 
Mw/Mn of &lt;1.03 for polystyrene standards run on the same basis. Thus, such 
corrections were not necessary. Similarly, the values for the derivative 
of the integral of the MWD with respect to log M at its maximum can be 
compared. A hydrogenated polybutadiene polyisoprene block polymer prepared 
by anionic polymerization has a value for this quantity of about 5.8. The 
narrowest PE-EP block polymer made to date in the mix free reactor and 
analyzed equivalently has a value of 2.6. The Mw/Mn is 1.12. A most 
probable MWD, that obtained in backmixed reactors with single site 
catalysts, has a theoretical and observed value of 1.5. The Mw/Mn is 2.0. 
d. Gel Permeation Chromatography/FourierTransform Infra Red Spectroscopy 
(GPC/FTIR) 
Compositional analysis across the molecular weight distribution was 
performed by operating a GPC instrument similar to that disclosed above 
with the effluent passed through a Fourier Transform Infrared photometer 
(FTIR) instead of the Low Angle Laser Light Scattering (LALLS) instrument. 
The composition of the eluting polymer was measured from characteristic 
methyl and methylene bands at 1377, 1154 and 1464, 730 cm.sup.-1 
respectively. Compositionally homogeneous copolymers of composition 
measured using the techniques described above in ASTM D 3900-95 were used 
to calibrate the FTIR. 
e. Melting Behavior 
Melting points and heats of fusion were determined by Differential Scanning 
Calorimetry (DSC). Strain free specimens were prepared by molding 
0.030".times.3".times.3" pads of the polymer at 150.degree. C. for 30 
minutes with subsequent cooling to 20.degree. C. at a rate of 30 degrees 
per minute. After cooling, the polymer was annealed for at least 24 hours 
at 20.degree. C. One to five mg. samples of the polymer were cut from the 
pad and loaded into the DSC at 20.degree. C. The sample was cooled to 
-100.degree. C. at a rate of 20 degrees per minute and then scanned at 10 
degrees per minute to 180.degree. C. 
The melting point was recorded at a maximum deviation from baseline on the 
first heat cycle. The upper limit at which all melting ceases with 
complete return to baseline can be as much as 15.degree. C. higher than 
the temperature at maximum deviation. 
Baselines were back-extrapolated from above the melting region to establish 
areas to be integrated for heat of fusion determination. Where baseline 
construction was ambiguous, shoulder to shoulder construction was also 
examined and an average value determined. A region from 90-130.degree. C. 
could be distinguished from a lower melting portion that extended from the 
annealing temperature of 20.degree. C. up to 70-80.degree. C. The upper 
temperature region is PE block and the lower region is the semicrystalline 
EP block. In the second melting run of the DSC, the EP crystallinity is 
much diminished due to its slower crystallization rate compared to the PE 
block. This aids in distinguishing the PE blocks from the EP blocks. 
Because the low temperature properties of the polymer in oil are relatively 
insensitive to the absolute amounts of crystallinity present, once the 
amount of crystallinity is above a minimum level for the PE block, the 
exact heats of fusion are not critical. It is the range over which the 
properties are good that is important. 
f. % PE block 
The heat of fusion of polymer melting between 95 and 135.degree. C. is an 
indication of the amount of PE block in the polymer. Measurement of the 
heat of fusion of pure polyethylene made with the catalyst system of this 
invention by the technique described above, yields a heat of fusion that 
averages 190 J/g. The heat of fusion in the PE melting region divided by 
190 is the fraction of PE in the block copolymer when the PE block 
contains no propylene. When propylene is present in the PE block, the heat 
of fusion is depressed and it is not possible to accurately determine the 
% PE block by DSC unless the amount of propylene in the block is known. In 
the absence of that information, the amount of PE block can be estimated 
by a heat balance in the PE section of the polymerization reactor when the 
reactor is operated adiabatically. The temperature rise in the PE section 
is proportional to the amount of PE produced. When the propylene content 
is known, the heat of fusion can be adjusted from the 190 J/g value and 
the % PE block calculated from the point at which the calorimetric value 
and heat balance are in agreement. 
A polymerization was carried out in the one inch diameter reactor in which 
the feed rate of propylene to the reactor inlet was varied at otherwise 
constant conditions. A water quench was injected into the reactor at the 
point where the first side stream would normally be injected so that only 
a PE block was formed. The propylene content of the polymer was analyzed 
by C13 NMR. The data in table below show the relationship between polymer 
composition, polymer melting point, and polymer heat of fusion, all at 
essentially constant molecular weight and MWD. 
__________________________________________________________________________ 
Polyethylene Blocks With No EP Block Attached 
Wt % 
Propene 
Weight 
In 
Propene/ 
Polymer 
Melting 
Heat Of 
Mn .times. 10.sup.-3 
Ethene in 
C13 Point Tm 
Fusion 
Elution 
Mw .times. 10.sup.-3 
Mw .times. 10.sup.-3 
Mw/Mn 
Feed NMR C J/g Time Elution Time 
LALLS Elution Time 
__________________________________________________________________________ 
0.0 0.0 132.3 
222.8 
16.7 25.4 23.2 1.5 
0.1 3.2 127.9 
187.1 
17.5 24.8 24.5 1.4 
0.2 4.3 124.8 
169. 
16.5 22.8 21.6 1.4 
0.3 5.5 120.4 
140.8 
17.5 25.9 22.9 1.5 
__________________________________________________________________________ 
These data as well as melting point vs main feed composition results from 
example 6 below are presented in FIG. 1. It is seen in FIG. 1 that the 
melting point of the PE block decreases as the propene content of the main 
feed is increased. The upper dashed line is drawn as a guide. A second 
lower dashed line passes through the melting points of an additional 8 
samples which have an EP block attached to the PE block. The lines are 
almost parallel. It is seen that for a given propene/ethene feed ratio the 
PE blocks with EP attached melt at about 6.degree. C. lower than PE blocks 
with no EP attached. This presumably is due to the constraints the EP 
block imposes on the PE packing into crystals. There is also an entropy of 
melting effect as the melted PE is now dissolved in a matrix which 
contains EP as well as PE. 
It should further be noted that the polymer described in the table, which 
are PE blocks by definition as no sidestreams were added, have different 
heats of fusion depending on propene content. To calculate a % PE block, 
one must know the propene content to determine the correct J/g for the 
block. 
It is very difficult to measure the propene content in the PE block once 
the PE block is attached to an EP block because the FTIR or C13 NMR cannot 
easily distinguish between methyl groups in the two parts of the molecule. 
Thus, the following convention is adopted to estimate the propene content 
of the PE blocks in the PE-EP block polymers. The measured Tm of the PE 
block in the PE-EP polymer is located on the lower dashed line of FIG. 1. 
That corresponds to a known feed ratio. It is assumed that the PE block 
composition is fixed by the feed ratio and the % propene can be 
interpolated from the known values for the PE with no EP block attached. 
This exercise need not be performed in the context of a plot which shows 
the melting points. However, the plot lends credence to the proper 
assumption that the same feed ratio produces the same % propene for both 
type polymers when the Tm vs feed ratio slope is so similar. Thus, at 0.2 
feed ratio, when the free PE block melts at about 125.degree. C. and the 
PE-EP block made with the same mainstream feed ratio melts at about 
119.degree. C., it is estimated that the propene content of the PE section 
of the two polymers is the same and equal to 4.3 weight % as shown in FIG. 
1. 
g. Solubility in Cyclohexane 
A polymer pad was formed in a hot press and 3-5 g of roughly cubic pieces 
of dimensions &lt;3 mm were cut from the pad with a scissors. These pieces 
were accurately weighed and placed in 250 cc of cyclohexane and allowed to 
stand for 3-5 days in a thermostatted oven at a chosen temperature between 
45.degree. C. and 65.degree. C., with periodic gentle agitation. At the 
end of this time, the mixture was passed through a fine mesh screen that 
had been previously tarred to filter the insoluble polymer. The screen was 
put into a vacuum oven to remove all solvent, and was then weighed to 
determine the quantity of insoluble polymer present. The solution passing 
through the screen was evaporated to dryness to recover the soluble 
fraction. 
The polymerization conditions are given in Table 4a. 
3 TABLE 4A 
- Preparation Conditions for PE-EP Block Polymers 
POLYMER ID 
NDG 5 NDG 7 NDG 12 NDG 29 NDG 30 NDG 31 NDG 40 NDG 41 NDG 42 NDG 
43 
Reactor Conditions (1) 
Main Feed 
Main feed temperature, .degree. C. (10) (10) 10 10 10 10 10 25 25 10 
VC14 0.185 0.487 0.315 0.52 0.4 0.44 0.4 0.4 0.4 0.4 
EASC, 15 wt % 7.05 18.8 11.8 18.2 14.2 14.9 14.89 14.89 14.89 14.89 
Hexane 1609.0 1621.8 1627.6 1634 1629.6 1630.5 1630.6 1630.6 1631 
1630.6 
Ethylene 5.7 6.27 10 12.3 6.7 10 10 10 10 10 
Propylene 0? 0? 1.49 4 2 2.85 1.2 1.2 1.2 
Side Feeds 
Side feed temperature, .degree. 
C. (0) (0) 0 0 0 0 0 0 0 0 Res. time to 1st side feed, sec 
1 .64 1.63 1.85 1.61 1.62 1.62 1.62 1.62 1.62 1.62 
Side Feed 1 
Hexane 200 200 200 200 200 200 200 200 200 200 
Ethylene 5.3 5.33 6.73 6.65 7.42 7 7 7 7 7 
Propylene 37.7 22.8 50.3 42.8 47.7 40.3 50 50 50 50 
Res. time to 2nd side feed, sec 1.94 1.93 2.16 1.9 1.91 1.91 1.91 1.91 
1.91 1.91 
Side Feed 2 
Hexane 200 200 200 200 200 200 200 200 200 200 
Ethylene 5.3 5.33 6.73 6.65 7.42 7 7 7 7 7 
Propylene 22.7 10 30.3 26.6 29.7 23.3 30 30 30 30 
Res. time to 3rd side feed, sec 3.7 3.69 3.87 3.61 3.63 3.63 3.62 3.62 
3.62 3.62 
Side Feed 3 
Hexane 200 200 200 200 200 200 200 200 200 200 
Ethylene 5.3 5.33 6.73 6.65 7.42 7 7 7 7 7 
Propylene 22.7 10 30.3 26.6 29.7 23.3 30 30 30 30 
Res. time to 4th side feed, sec 
Side Feed 4 
Hexane 
Ethylene 
Propylene 
Res. time to 5th side feed, sec 
Side Feed 5 
Hexane 
Ethylene 
Propylene 
Res. time to 6th side feed, sec 
Side Feed 6 
Hexane 
Ethylene 
Propylene 
Res. time at quench, sec 5.14 5.16 5.28 4.56 4.57 4.58 8.21 8.21 4.09 
4.09 
Reactor outlet temp., .degree. C. 27.4 31.6 25.8 30.9 30.5 22.2 
Polymerization rate, kg/hr 17 30 41.9 42.8 37.5 35.7 28.3 
(1) Feed rates Kg/hr, T or C 
1-inch reactor 
POLYMER ID 
(2) 5/13/96 7/14/96 7/14/96 7/14/96 9/23/96 9/23/96 9/23/96 9/23/96 
1/20/97 1/20/97 1/20/97 1/21/97 1/21/97 1/21/97 1/21/97 
10:37 12:28 13:21 13:54 14:40 15:10 15:40 16:30 15:00 17:00 22:00 
0:45 1:35 4:00 6:00 
Reactor Conditions (2) 
Main Feed 
Main feed temperature, .degree. F. 28.9 27 27 27 50 50 50 50 53.1 53.1 
5 3.1 47.8 43 34.5 34.5 
VC14 0.101 0.0772 0.0534 0.0611 0.0685 0.0685 0.0685 0.047 0.089 
0.0801 0.0722 0.0722 0.0722 0.0722 0.0722 
EASC, 100% 0.502 0.387 0.268 0.306 0.342 0.342 0.342 0.235 0.445 0.40 
0.351 0.361 0.361 0.361 0.361 
Hexane 64.1 135.5 147.6 129.1 129 129 144 115 173 173 173 173 173 173 
173 
Ethylene 2.27 2.11 2.19 2.15 2.15 2.15 2.15 1.15 2.77 2.77 2.77 2.77 
2.77 2.77 2.77 
Propylene 0.536 0.54 0.54 0.55 0.27 0 0 0 0.55 0.55 0.47 0.47 0.47 
0.47 0.47 
Side Feeds 
Side feed temperature, .degree. F. 19.2 19.3 19.3 19.3 -40.9 -40.9 
-40.9 -40.9 -40 -40 -40 -40 -40 -40 -40 
Res. time to 1st side feed, sec 0.52 0.52 0.48 0.55 0.68 0.68 0.56 
0.79 0.27 0.27 0.27 0.27 0.27 0.27 0.27 
Side Feed 1 
Hexane 11 11.1 11.4 10.96 16.6 16.6 16.5 21 16.8 16.8 16.8 16.8 16.8 
16.8 16.8 
Ethylene 1.12 1.01 0.983 1.01 1.47 1.47 1.33 0.7 1.68 1.68 1.68 1.68 
1.68 1.68 1.68 
Propylene 5.12 4.86 4.83 4.91 7.15 7.15 7.15 3.43 13.5 13.5 13.5 13.5 
13.5 13.5 13.5 
Res. time to 2nd side feed, sec 0.65 1.05 0.97 0.69 0.68 0.68 0.56 
0.79 0.42 0.42 0.42 0.42 0.42 0.42 0.42 
Side Feed 2 
Hexane 11 11.3 11.4 10.96 16.6 16.6 16.5 21 17.9 17.9 17.9 17.9 17.9 
17.9 17.9 
Ethylene 1.12 1.02 0.983 1.01 1.47 1.47 1.33 0.7 1.96 1.96 1.96 1.96 
1.96 1.96 1.96 
Propylene 5.12 4.92 4.83 4.91 7.15 7.15 7.15 3.43 6.2 6.2 6.2 6.2 6.2 
6.2 6.2 
Res. time to 3rd side feed, sec 0.91 1.29 1.22 0.94 1.06 1.06 1.26 
1.69 0.54 0.54 0.54 0.54 0.54 0.54 0.54 
Side Feed 3 
Hexane 11.9 13.4 13.6 13.2 16.6 16.6 16.5 21 22.4 22.4 22.4 22.4 22.4 
22.4 22.4 
Ethylene 1.03 1.22 1.17 1.22 1.47 1.47 1.33 0.7 1.96 1.96 1.96 1.96 
1.96 1.96 1.96 
Propylene 4.69 5.86 5.76 7.15 7.15 7.15 3.43 6.2 6.2 6.2 6.2 6.2 6.2 
6.2 
Res. time to 4th side feed, sec 1.04 1.75 1.67 1.05 1.71 1.71 2.18 2.8 
Side Feed 4 
Hexane 12.7 13.4 13.6 13.2 
Ethylene 0.479 1.22 1.17 1.22 
Propylene 2.19 5.86 5.76 5.92 
Res. time to 5th side feed, sec 1.15 
Side Feed 5 
Hexane 14.5 
Ethylene 0.479 
Propylene 2.19 
Res. time to 6th side feed, sec 1.27 
Side Feed 6 
Hexane 18.6 
Ethylene 0.479 
Propylene 2.19 
Res. time at quench, sec 5.34 7.31 7.15 7.65 7.43 7.43 7.62 7.62 2.64 
2.64 2.64 2.64 2.64 2.64 2.64 
Reactor outlet temp., .degree.F. 135 125.3 121.1 122 106.8 104.8 
98.97 98.7 93.3 87.1 90.9 
Polymerization rate, klb/hr 10.5 11.1 10.8 10.6 11 9.96 9.59 6.3 
(2) All feed rates in klb/hr, temperature in .degree. 
F. 5-inch reactor 
POLYMER ID 
374B 350E 318A 318B 366B 380B 420A 368C 
Main Flow g/h 
Hexane 53064 53807 53803 53803 54358 43164 53737 53460 
Ethylene 270 263 46 46 270 181 274 180 
Propylene 0 0 0 0 0 0 0 0 
VC14 2.5 3.2 2.4 2.4 3.5 2.5 4.5 2.5 
At/V 6 8 8 8 8 6 7 8 
Side Stream 1/g/h 
Hexane 6178 5940 8910 8910 6138 6019 6178 6178 
Ethylene 100 75 100 100 100 100 100 1100 
Propylene 1100 827 1070 1070 1137 1119 1100 1148 
Side Stream 2, g/h 
Hexane 8831 5940 6415 6415 8989 8870 8910 8950 
Ethylene 100 75 77 77 100 100 100 100 
Propylene 400 319 258 258 425 435 438 423 
Side Stream 3, g/hr 
Hexane 6178 0 5940 5940 6205 6613 6494 6455 
Ethylene 0 0 48 48 0 0 0 0 
Propylene 0 0 148 148 0 0 0 0 
ENB 6.5 6.6 13.8 9.9 7.2 
Side Stream 4, g/hr 
Hexane 396 
ENB 8 
Temperature, .degree. 
C. Premix 18.2 12.1 10.2 
9.1 12.4 18.5 11.9 12 
Main 24.3 20 20.1 14.8 15.3 20.2 21.1 24.9 
Side Stream 1 17.3 
Side Stream 2 17.2 17.4 12.7 13 17 17.6 19.5 16 
Side Stream 3 N/A N/A 15.1 15.3 17.1 17.1 17.1 15.8 
Reactor Outlet 28.4 26.8 20.8 20.9 24 24.3 27.4 25.8 
Residence Time, min. 
to Side Stream 1 0.0245 0.0242 0.0243 0.0243 0.0239 0.0301 0.0242 
0.243 
to Side Stream 2 0.0669 0.0664 0.0645 0.0645 0.0654 0.081 0.0661 
0.0665 
to Side Stream 3 0.1455 0.0664 0.1054 0.1054 0.1059 1.1728 0.1265 
0.108 
to side Stream 4 
Quench 0.1839 0.1483 0.1772 0.1395 0.1772 0.2168 0.1803 0.179 
3/8-inch reactor 
TABLE 4B 
__________________________________________________________________________ 
Properties of PE-EP Block Polymers 
Estimated 
Heat of Heat of 
Wt % Wt % Fusion Fusion 
Ethene Propene PE Tm EP EP Max in 
Whole % PE in PE Tm PE Block Block Block Mw .times. Mw/ dI (m)/ 
Sample ML Polymer Block 
Block Block J/g .degree. 
C. J/g TE 10 -3 Mn d log 
__________________________________________________________________________ 
m 
NDG 12 
8.9 
69 19.8 
3.7 120 39 43 0.3 2.8 
98 1.42 
2.6 
NDG 29 7.4 69.7 18 5.7 116 33 1.5 2.27 93 2.05 
NDG 30 7.3 66.9 9.3 5.5 115 15 0 2.28 95 2.4 
NDG 31 10.6 72.5 21 5.2 118 37 1.2 2.58 103 2.0 
NDG 40 4.9 63.8 13.8 128 68 1.49 2.46 
NDG 41 7.2 64.7 17.6 126 89 1.69 2.06 
NDG 42 3.8 71.3 21.5 128 68 1.61 2.43 
NDG 43 2.2 68.4 22.4 125 61 1.46 2.59 
5/14/96 6.2 70 15 6.5 109 28 47 6. 1.56 
13:30 
7/15/96 8.2 69 13 6.3 111 29 47 8. 1.53 
14:10 
9/24/96 13.3 69 17 4.7 117 36 46 3. 2.6 115 1.82 1.67 
14:40 
9/24/96 13.9 70 21 4.0 120 38 2.75 113 1.81 1.68 
15:10 
9/24/96 14.9 70.3 20 5.5 115 37 3.05 118 1.86 1.55 
15:40 
9/24/96 12.6 69.7 20 5.0 117 36 114 1.75 1.9 
16:30 
9/24/96 12.2 70. 20 4.3 119 36 46 3. 3.26 115 1.72 2.0 
17:00 
1/20/97 7.1 70 20 4.0 115 26 48 6. 2.36 104 1.68 1.9 
15:00 
1/20/97 8.6 70.1 21 4.0 2.5 108 1.7 1.9 
17:00 
1/20/97 12.1 71 19 4.0 115 2.4 48 9. 
22:00 
1/21/97 11.3 71 20 4.0 117 25 50 8. 
06:00 
701204095 7 71 15 5.5 115 28 46 5. 2.4 98 1.6 
701214280 12 71 5.3 117 28 46 8. 3.38 119 1.61 
NDG 5 32 73 20 0 126 35 4.4 150 1.5 1.8 
NDG 7 2.3 73 20 0 126 36 2.1 72 2.05 
374B 76 49 0 3.7 
350E 20 74 47 0 132 86 4.5 148 1.9 -- 
420A 72 44 0 3.0 
366B 71 40 0 3.3 
380B 71 36 0 4.1 
368C 70 34 0 3.76 
VSV 10/29 69 28 0 3.7 
318A 11 64 14 0 127 28 2.8 118 1.7 
318B 8 63 14 0 123 25 3.0 118 1.9 
__________________________________________________________________________ 
During the polymer production process all samples were recovered from the 
solvent by steam distillation. All of the samples have a PE block melting 
point above 109.degree. C. All samples (with the exception of the 
NDG-40-43 series, which were reactor sampled only) could be recovered by 
steam distillation without particle agglomeration problems, including 
samples down to Mw of 80K, unlike the polymers of Comparative Example 3. 
Example 5 
In this example selected samples prepared in Example 4 above were tested 
for SSI and high and low temperature viscometric properties. The oil 
formulation is as follows with the correct amount of polymer being added 
to get the correct 100.degree. C. kv for the oil grade: Mobil 15W40, 71.2 
wt % Mobil 150NS, 21.5 wt. % Mobil 300NS, 7.3 wt. % ESN 130, 0.22 wt % 
AFLOW 387. 
TABLE 5 
__________________________________________________________________________ 
Properties of PE-EP Block Mix Free Reactor and Poly(ethene-co-propene) 
Polymers In Lubricating Oils 
SSI 
PP CCS HTHS VI in Mobil 
Sample TE % .degree. C. TP1 cP cP Haze cP Formulation Paulsboro* 
__________________________________________________________________________ 
NDG 12 
2.8 
18 -27 
9420 
3160 
16 Mobil 178 
15W40 
NDG 12 2.8 18 -33 8225 3090 15 Mobil 
10W30 
NDG 29 2.27 13 179 
NDG 30 2.28 12 145 
NDG 31 2.65 26 167 
5/14/96 2.4 32 
13:30 
7/15/96 2.47 25 
14:10 
9/24/96 2.6 27 
14:40 
9/24/96 2.75 32 
15:10 
9/24/96 3.05 42 
15:40 
9/24/96 3.26 49 
17:00 
701204095 2.4 24 -27 8870 3210 14 4.1 Mobil 
15W40 
701204095 2.4 24 -30 9840 3075 3.4 Mobil 
10W30 
701214280 3.38 41 
878 3.3 50 -33 11,000 3000 180 2.5 148 
91-9 2.7 37 -33 11,000 3200 140 2.8 146 
__________________________________________________________________________ 
*Mobil Paulsboro is a basestock marketed by Mobil Oil Corp. 
Viscosity Index (VI) is measured according to D2270-93. The higher the 
value the less the kinematic viscosity (kv) increases as temperature 
decreases. 
When the results of this set of experiments is regressed the following 
interrelationship of SSI, TE and MWD is found: 
EQU log SSI=1.17+(1.82.+-.0.23) log TE-(0.29.+-.0.055) MWD Peak Max. 
The narrower the MWD, as measured by the height at peak max., the lower the 
SSI at a given TE. 
Example 6 
The TE-SSI performance of selected polymers from Comparative Example 1 and 
Example 5 is compared in FIG. 2. Also measured and included in the Figure 
is TE-SSI data for products currently marketed by Shell Chemical, Shellvis 
200, 260 and 300. These are hydrogenated "star" branched polymers made 
anionically from polyisoprene. When hydrogenated they have the same 
composition as an alternating ethene propene copolymer (i.e. 50 mole % 
ethene) with a few percent isopropyl side groups from 3,4 isoprene 
addition in the anionic polymerization. These star branched polymers 
represent the most shear stable prior art polymer for their TE on the 
commercial market today. They get their stability from narrow MWD and the 
branched polymer structure which distributes the breaking stresses across 
the bonds in a different way than for linear polymers and also from the 
fact that when one "arm" is broken off such a structure the decrease in 
viscosity is not large. The alternate side of that behavior is that star 
molecules continue to degrade at a rather constant rate with time rather 
than reaching a steady viscosity as linear molecules which break at the 
center do. Once broken, linear molecules are much less susceptible to a 
second break than the stars which are not substantially altered by single 
breaks. 
It is clear from FIG. 2 that the PE-EP block polymer (PE-EP blocks with 
peak max at 2.6 according to the regression equation of Example 5) 
provides a lower SSI for a given TE compared to the prior EP technology. 
The performance is as good as the Shell star polymers. It is the high 
ethene content of the PE-EP blocks which gives them the boost compared to 
previous EPs. Higher ethene content means fewer tertiary hydrogens in the 
polymer backbone, which yields greater carbon-carbon bond strength. At a 
given molecular weight, high ethene content polymers have a higher 
intrinsic viscosity and TE compared to low ethene content polymers. If a 
lower molecular weight polymer can be used to thicken the oil, a given 
weight of polymer will contain more molecules, and more bond breaks are 
needed to degrade the given weight of polymer. The credit can also be 
taken as less polymer is needed to thicken the oil at a given SSI. Oil 
performance is set by the SSI the marketer chooses to sell. If a higher TE 
polymer can be used at a given SSI, less polymer must be used. Polymer 
costs more than oil thus the PE-EP polymer is more cost effective. 
Example 7 
In Table 7a the TE-SSI performance of several PE-EP block polymers of 
similar TE but varying PE block content is compared. It is seen in FIG. 3 
(in which the numbers designate the ethene content of the samples) that as 
block content is increased performance increases as measured by higher TE 
at a given SSI. However above 25% PE block the trend reverses and SSI 
appears to increase disproportionately. Backmixed reactor polymers 
V457(ATONE 715 is a solution of V457 in oil) and 90-9 are included for 
reference. 
TABLE 7A 
__________________________________________________________________________ 
TE-SSI Performance of PE-EP Block Polymers vs PE Block Content 
d in K/ 
d in K/ 
Wt % Wt % dT dT PE 
Ethene Propene SSI SSI Ratio of before after Block 
ML @ Whole % PE in PE TE @ TE @ TE @ SSI 100 C/ KO .times. KO .times. 
Too 
Sample 150 C Polymer Block Block 100 C 100 C 150 C 150 C 10.sup.3 
10.sup.3 Large? 
__________________________________________________________________________ 
V457 15* 44 0 na 2.8 53 50 1.06 -3.0 
-1.8 
no 
90-9 9.5* 65 0 na 2.7 40 40 1.0 -2.4 -2.3 no 
NDG 30 11 64 8 4 2.3 8 no 
318A 11 64 14 0 2.8 25 26 0.96 -4.3 -3.6 no 
NDG 12 9 69 19 4 2.8 18 18 1.0 no 
NDG 29 7.4 70 18 5 2.3 18 no 
NDG 31 10.6 72 21 5.2 2.6 26 27 0.96 no 
380B 97 71.4 36 0 3.9 72 53 1.36 -8.3 1.8 yes 
366B 23 71 46 0 2.5 47 16 2.9 -6.9 2.2 yes 
374B 93 76 49 0 4.4 73 46 1.59 -6.7 7.0 yes 
__________________________________________________________________________ 
*ML @ 125.degree. C. 
However, if the kinematic viscosities before and after degradation are 
measured at 150.degree. C. instead of the standard 100.degree. C., the SSI 
is seen to be small for the high block content polymers, as shown in FIG. 
4 (in which the numbers designate the ethene content of the samples). 
There are more high block content polymers to the right in FIG. 4 than in 
FIG. 3. The ratio of the two SSIs is shown in the Table 7a. 
If the molecular weight of the degraded polymer is measured it is seen that 
even though the TE has dropped considerably for the high PE block content 
polymers after KO treatment when kinematic viscosity is measured at 
100.degree. C., the Mw has not dropped and an SSI based on molecular 
weights would show those samples to be good performers. 
The data of FIG. 5 illustrates the poor SSI performance for polymers having 
a PE block content that is greater than, or equal to, 30 wt. %. The 
polymer contribution to the kinematic viscosity of the oil solution is 
proportional to the concentration and intrinsic viscosity of the polymer. 
In turn, the intrinsic viscosity is proportional to the size of the 
polymer molecule in solution. It is known that the size of properly 
dissolved PE and EP decreases as the temperature is raised. The higher the 
ethene content, the larger the change, as shown by the filled symbols of 
FIG. 5. When the polymer molecules are degraded, the molecules having a 
high PE block content will have fragments that are substantially pure PE 
block. Such molecules are not soluble in oil at 100.degree. C. Thus the 
contribution of these molecules to the kinematic viscosity of the oil is 
greatly reduced. As shown in FIG. 5, after degradation, those polymers 
containing 25 to 30 wt. % PE block actually expand as the temperature is 
increased. This behavior reflects the increased solubility of the 
precipitated PE block as the temperature is raised and the PE blocks melt. 
Therefore, the PE block content should be below 25 to 30 wt. % for optimal 
apparent SSI performance, and above 5 to 10 wt. % for slurry stability 
during manufacturing. 
Example 8 
In this example samples with varying PE block content and Tm are compared 
regarding performance in the solvent stripping and slurrying operations of 
manufacture. Results are shown in Table 8. 
TABLE 8 
__________________________________________________________________________ 
Steam Distillation Performance of PE-EP Block Polymers vs PE Block 
Content 
Wt % Polymer 
Propene Viscosity @ 
SSI in % PE in PE Tm 110 C Operation Of Steam 
Sample ML ENJ102 Block Block C 10.sup.6 poise Distillation Unit 
__________________________________________________________________________ 
Vistalon 878 
55 @ 125 C 
50 0 -- &lt;70 
5 Excellent 
90-9 20 30 0 -- &lt;70 1 Satisfactory 
BR730 12 24 0 -- &lt;70 &lt;0.1 Inoperable 
NDG 9A 10 @ 150 C 20 4 0 115 0.5 Poor 
NDG 30 7.3 12 15 5 123 &gt;100 Excellent 
NDG 12 8.9 19 20 5 123 &gt;100 Excellent 
NDG 29 7.4 13 25 5 123 &gt;100 Excellent 
95-9 A 20 3 118 &gt;100 Excellent 
95-9 B 12 45 20 5 113 &gt;100 Excellent 
95-9 C 20 7 108 &lt;0.1 Inoperable 
95-9 D 7 24 18 5 115 &gt;100 Excellent 
__________________________________________________________________________ 
*To be rated Excellent, the rubber particle size in the steam flash tank 
must show no tendency to agglomerate to form particles having a diameter 
that is larger than 1 to 2 cm. To be rated Satisfactory, the particles 
must not agglomerate when a slurry aid such as calcium stearate is used i 
an amount of 0.5 wt. %. Inoperable means that the steam flash tank is 
plugged with rubber as soon as the polymer is flashed into the tank, 
causing the shutdown of the process. 
It is seen that the performance is determined by a combination of Tm and 
molecular weight as determined measured by Mooney viscosity. For the 
traditional mix free reactor polymers below about 20 ML and 30 SSI, the 
bulk viscosity is too low and the process will not operate. On the other 
hand when a high melting PE block is present with a Tm above 110.degree. 
C. the process operates down to 7 ML (150.degree. C.) producing a polymer 
of 24 SSI, which is not possible without the PE block's presence. 
There is a balance between block length and Tm but there must be at least 
10% PE block length present to have an operable process. 
Example 9 
In this example the SSI performance of PE-EP block polymers is examined as 
a function of the process conditions employed to make the polymer. 
At a given TE the SSI is lower the narrower the MWD of the polymer. 
Empirically it was shown in Example 5 that the maximum value for the 
derivative of the integral of the molecular weight distribution, d I(M)/d 
log M, is a predictive measure of the effect of MWD on SSI at a given TE. 
The larger the value for this quantity the lower the SSI at a given TE. 
Table 9 presents MWD information, and thus SSI predictions, as a function 
of the relevant polymerization variables. Specifically, polymerization 
data for a number of the runs shown in Table 4a are set forth in Table 9 
to demonstrate the criticality of reactor conditions on the preferred 
narrow molecular weight distribution and TE and SSI characteristics of the 
resulting copolymers. The three runs identified as Sep. 24, 1996 differ 
primarily in polymer concentration at the reactor outlet. It can be seen 
from the MWD peak measurements that the highest MW peak is obtained at low 
polymer concentration, which also corresponds to low reactor outlet 
temperature. 
The four runs labeled Jan. 22, 1997 and Jan. 23, 1997 differ primarily in 
reactor feed temperature, which was varied from 1.0 to 11.5.degree. C. The 
MW peak value goes through a maximum as feed temperature is reduced. MW 
peak value first increases as feed temperature and outlet temperature 
decrease, but then begins to decrease at a temperature of 1.0.degree. C. 
Certain experiments reported in Table 9 were conducted in a one inch 
reactor using various feed temperatures, polymer concentrations and 
reactor times. The MW peak value was shown to increase as each of feed 
temperature, polymer concentration and reaction time was reduced. The 
highest value for MW peak was obtained when all three parameters were at 
their lowest level simultaneously. From these examples, it is clear that a 
preferred range of reactor conditions exist for producing polymer products 
with the desired SSI and TE characteristics. 
TABLE 9 
__________________________________________________________________________ 
Polymer 
Conc. 
Main wt/100 Reactor Reaction MWD 
Feed T wt Outlet T Time Peak 
Sample Mooney deg .degree. C. hexane .degree. C. (sec) Mw/Mn Max 
__________________________________________________________________________ 
FIVE INCH REACTOR 
9/24/96 14:40 13.3 10 6.15 48 7.43 1.84 1.68 
9/24/96 15:40 14.9 10 4.96 42 7.62 1.87 1.55 
9/24/96 16:30 12.6 10 3.54 24 7.62 1.76 1.91 
1/22/97 22:00 12.1 11.5 5.50 37.0 2.64 1.83 1.85 
1/23/97 00:45 10.8 9 5.50 37.0 2.64 1.71 1.93 
1/23/97 01:35 9.1 6 5.50 33.5 2.64 1.70 1.97 
1/23/97 04:00 9.6 1 5.50 33.5 2.64 1.78 1.86 
ONE INCH REACTOR 
NDG 44 21.9 10 3.28 40.0 8.05 1.71 1.78 
NDG 45 27.4 25 3.04 45.4 8.05 1.92 1.46 
NDG 46 10.1 25 2.62 39.1 4.03 1.79 1.83 
NDG 47 5.7 10 2.95 32.8 4.03 1.49 2.41 
__________________________________________________________________________ 
For practical operation it appears that the cement concentration should be 
below 6% and the inlet temperature above 5.degree. C. with the outlet 
temperature below 40.degree. C. 
Furthermore it is advantageous from a MWD and SSI performance to quench the 
reaction before significant monomer transfer occurs. Too early a quench 
however reduces production rate and an optimum must be found to produce 
the most cost effective product. 
Sidestream location must not be too late or significant termination or 
transfer reactions can occur leaving molecules which have the molecular 
length associated with the subsequent sidestream feed unattached to the 
molecule. An MWD with a series of modes can be created. Fragments of 
unattached PE and EP are created which fragments perform in an inferior 
manner as far as TE-SSI and low temperature properties are concerned. 
Example 10 
In this example selected polymers from Example 4 are characterized with 
regard to compositional distribution (CD), and how pure the PE-EP block 
structure is. Samples were extracted with cyclohexane at 55.degree. C. as 
described in Example 4, section g. Soluble and insoluble fractions were as 
shown in Table 10. The soluble and insoluble fractions were subjected to 
GPC with on line FTIR analysis to obtain the ethene content. Typical 
results are shown in FIGS. 6, 7 and 8. 
TABLE 10 
__________________________________________________________________________ 
Insoluble 
Fraction Soluble 
Wt. % Fraction Wt. % 
Sample % Soluble Ethene Mw Mw/Mn Mp Ethene Mw Mw/Mn 
__________________________________________________________________________ 
1/21/97 
15.4 73 115 
1.56 
1.56 
60 69 2.2 
01:35 Re 
1/21/97 11.7 71 124 1.47 2.25 68 68 2.1 
06:00 Re 
1/20/97 17.7 72 107 1.58 1.58 71 71 1.9 
15:00 FD 
1/21/97 17.9 73 119 1.58 1.58 75 75 2.1 
04:00 FD 
__________________________________________________________________________ 
It is seen that the soluble portion ranges from 11 to 18%. The average 
composition is about 60 weight % ethene. The insoluble fraction has an 
ethene content of about 72%. 
The GPC data shows the weight average molecular weight, Mw, of the soluble 
fraction to be about 70,000 and the insoluble fraction to be about 
115,000. There is a shift in the MWD peak to lower molecular weight in the 
soluble fraction from over 100,000 to less than that value. Although 
applicants do not wish to be bound by any one theory, this is consistent 
with the absence of a PE block in the soluble portion and its formation by 
a transfer reaction after most of the mainstream ethene was consumed. 
The FTIR data in FIGS. 6 through 8 show that the low molecular weight 10 
portion of the MWD of the soluble fraction is about 45 weight % ethene and 
the composition rises with molecular weight to a value of about 60 weight 
% at the maximum in the MWD. Still higher molecular weight soluble 
fraction reaches the average of the whole polymer at about 70 weight %. 
There may be some small amount of PE block in the soluble fraction which 
tends to raise the ethene content of the highest molecular weight 
fraction. 
The insoluble fraction has the correct average ethene content for the whole 
polymer across the main peak as expected. At low molecular weight the 
composition trends towards that of the PE block alone, above 90% ethene. 
Apparently some portion of the polymer chains stop growing before or soon 
after the first sidestream feed. 
While several embodiments in accordance with the invention have been shown 
and described, it is to be clearly understood that the same are 
susceptible to numerous changes apparent to one of ordinary skill in the 
art. Therefore, the invention should not be deemed to be limited to the 
details shown and described above, and should be considered to show all 
changes and modifications which come within the scope of the appended 
claims.