Note: Descriptions are shown in the official language in which they were submitted.
1056546
This invention provides a process for the poly-
merization of ~-olefins utilizing a catalyst which is
sufficiently ~ctive, even at solution polymerization tem-
peratures to produce such high quantities of polymer per
unit of catalyst that it is no longer necessary to remove
catalyst residue in order to obtain a polymer o the
desired purity.
More particularly, the invention provides a
process or the polymerization of an ~-olefin und~r con-
ditions characteristic of Zie~ler polymerization in thepresence of a catalytic amount of a catalytic reaction
product of (A) compound of a transition metal ~TM), (B)
an organomagnesium component selected from (1) an organo-
magnesium compound or (2) a complex of an organomagnesium
compound and an organometallic compound in an amount
sufficient to solubilize the organomagnesium co~pound in
hydrocarbon and (C) a non-metallic halide corresponding to
the formula R'X wherein R' is hydrogen or a hydrocarbyl
group containing a labile halogen atom as easily lost to
another compound as the chloride atom of sec-butyl chloride,
and X is halogen; said reaction product being produced in
a manner such that the organomagnesium component reacts
with the non-metallic halide to form a hydrocarbon insoluble
portion, and further provided that aluminum, in th~ form
of a hydrocarbyl-aluminum compound represented by the
formula R3 aAlX wherein R is hydrocarbyl, X is halide and
a is a number from 0 to 1.0, is present in the catalytic
reaction product in an amount sufficient to provide a
reaction product that is catalytic for the polymerization
of an ~-olefin; the proportions of the components of
17,712-F
B
~05~;S4t;
catalytic reaction p.roduct~eing such that the atomic
ratio of Mg:TM is within the range from 20:1 to 2000:1,
the atomic ratio of X:TM is within the range from 40:1
to 2000:1, the atomic ratio of Mg:X is within the range
from 0.1:1 to 1:1, the atomic ratio of Mg:Al is more than
0.3:1, and the atomic ratio of Al:TM is less than 120:1
and the process is carried out at a polymerization tem-
perature above 150C.
In view of the reduced activity of conventional
Ziegler catalysts at solution polymerization temperatures,
it is indeed surprising that the catalytic reaction pro-
duct of this invention is a high efficiency catalyst
capable of producing more than a million weight parts
of olefin polymer per weight part of transition metal
17,712-F -la-
:1(3S65~i
at polymeri~ation temperatures greater than 150C, e.g.,
from 185 to 220C and higher. Accordingly, olefin
polymers produced in accordance with the foregoing pro-
cess generally contain lower amounts of catalyst residues
than polymers produced in the presence of conventional
catalysts even after subjecting such polymers to catalyst
removal treatments. Further, these catalytic reaction
products enable a higher degree of control over the
polymerization in order that a more uniform product can
be made. Additionally, polymers produced in the practice
of the present invention often have very narrow molecular
weight distributions and are therefore highly useful
in molding applications such as injection molding, film
application and rotational molding.
The present invention i5 most advantageously
practiced in a polymerization process wherein an a-olefin
is polymerized, generally in the presence of hydrogen
as a molecular weight control agent, in a polymerization
zone containing an inert diluent and the reaction product
as hereinbefore described~ The polymerization process
is most beneficially carried out under inert atmosphere
and relatively low temperature and pressure, although
very high pressures can be employed.
Olefins which are suitably polymerized or co-
polymerized in-the practice of this invention are gen-
erally the aliphatic a-monoolefins having from 2 to 18
carbon atoms such as, for example, ethylene, propylene,
butene-l, pentene-l, 3 methylbutene-l, hexene-l, octene-l,
dodecene-l, and octadecene-l. The a-olefins may be
1/,712-F 2
~C~56S46
copolymerized with other ~-olefins and/or with small
amounts, i.e., up to 10 weight percent based on the
polymer, of other ethylenically unsaturated monomers
such as butadiene, isoprene, pentadiene-1,3, styrene,
a-methylstyrene and similar ethylenically unsaturated
monomers which do not destroy conventional Zieyler cata-
lysts. Most beneits are realized in the polymerization
of aliphatic a-monoolefins, particularly ethylene and
mixtures of ethylene and up to 10, especially from 0.1
to 5, weight percent of propylene, butene-l or similar
higher a-olefin based on total monomer.
Advantageously, the novel catalyst composi-
tion of the present invention is the reaction product
of (A) a compound of a transition metal (hereinafter
called "TM") of Groups 4b, 5b, 6b, 7b and 8 of Mendeleev's
Periodic Table of Elements as shown in The Chemical Rubber
Company's Handbook of Chemistry and Physics, 48th edition,
and (B) an intermediate raaction product of (a) a hydro-
carbon soluble organomagnesium compound or a hydrocarbon
soluble complex of an organomagnesium compound and an
organometallic compound having the formula MRy wherein
M is a metal of Groups 2b, 3a including boron, la, 4a
including silicon; R is a monovalent hydrocarbon radical,
i.e., hydrocarbyl, such as alkyl, cycloalkyl, alkenyl,
aryl, arylalkyl and alkylaryl, or other monovalent organic
radical such as, for example, alkoxy, aryloxy, and
alkoxyalkyl; and y is a number corresponding to the
valence of M, and (b) an active non-metallic halide
corresponding to the formula R'X wherein R' is hydrogen
17,712-F ~3~
1056546
or hydrocarbyl such as, for example, alkyl and aryl and
that are at least as active as sec butyl and X is halogen,
preferably chloride, bromide, or iodide. The organic
moieties of the aforementioned catalyst components, e.g.,
R and R', are suitably any other organic radical provided
that they do not contain unctional groups that poison
conventional Ziegler catalysts. Preferably such organic
moieties do not contain active hydrogen, i.e., those
sufficiently active to react with the Zerewitinoff re-
agent. The catalyst composition preferably has an atomic
ratio of Mg:TM in the range from 30:1 to 200:1, most
preferably from 30:1 to 60:1; an atomic ratio of Mg:X
in the range from 0.2 1 to 0.7:1, most preferably from
0.4:1 to 0.6:1; and an atomic ratio of X:TM in the range
from 50:1 to 400:1, most preferably from 60:1 to 120:1.
Of the suitable transition metal compounds,
those of titanium, vanadium, zirconium are more advan-
tageously employed, with those of titanium being most
advantageous. Beneficial compounds are the halides,
oxyhalides, alcoholates, amides, acetylacetonates, alkyls,
aryls, alkenyls, and alkadienyls. The alcoholates of
titanium, so-called titanates, are the most beneficial.
Of the titanates, preferred ones are alkoxides
or aryloxides, especially alkoxides having from 1 to
12 carbon atoms or a phenoxide, of trivalent or tetra-
valent titanium. Such titanates are preferably derived
from halides of trivalent or tetravalent titanium includ-
ing alkyl titanium halides wherein one or more halogen
atoms are replaced by an alkoxy or aryloxy group. Exemplary
17,712-F ~4~
~OS6546
preferred -titanates include tetrabutoxytitanium, tetra-
(isopropoxy)titanium, diethoxytitanium bromide, dibutoxy-
titanium dichloride, n-butyltriisopropoxytitanium, ethyl
dibutoxytitanium chloride, monoethoxytitanium trichloride,
and tetraphenoxytitanium. Of the prefer~ed titanates,
the tetravalent ones wherein all halogen atoms are re-
placed by alkoxide are most preferred, with tetra(iso-
propoxy)titanium and tetrabutoxytitanium being especially
preferred.
Examples of other transition metal compounds
which are advantageously employed are titanium tetra-
chloride, titanium trichloride, vanadium trichloride,
vanadium tetrachloride, vanadium oxychloride, zirconium
tetrachloride, titanocene dichloride, zirconium tetra-
alcoholates such as tetrabutoxyzirconium, and vanadium
acetylacetonate.
The preferred organomagnesium complex is a
hydrocarbon soluble complex illustrated by the formula
MgR~ xMRy wherein R is hydrocarbyl, M is aluminum, zinc
or mixtures thereof and x is 0.001 to lO, especially
from 0.15 to 2.5 and y denotes the number of hydrocar-
byl groups which corresponds to the valence of M. This
complex is prepared by reacting particulate magnesium
such as magnesium turnings or magnesium particles with
about a stoichiometric amount of hydrocarbon halide,
illustrated as RX. The resulting hydrocarbon insolu-
ble MgR2 is then solubilized by adding the organometallic
compound such as AlR3 or mixtures thereof with ZnR2.
When employing a mixture of AlR3 and ZnR2 to solubilize
17,712-~ -5-
~056S46
MgR2, the atomi~ ratio of Zn to Al is from 3000:1 to
0.01:1, preferably from 350:1 to 1:1. The amount of
organometallic compound which is added to the MgR2 to ~orm
the organomagnesium complex should be enough to solubilize
a significant amount of MgR2, e.g., at least 5 weight per-
cent o~ MgR2 is solubilized. It is pre~erred to solubilize
at least 50 weight percent of the MgR2 and especially pre-
~erred to solubilize all of MgR2. In order to obtain
maximum catalyst efficiency at polymerization temperatures
above 180C, it is desirable to minimize the amount of
aluminum in the complex as well as in the total catalyst.
In catalyst systems employing aluminum, it is desirable that
the Al:TM atomic ratio be less than 120:1, preferably less
than 40:1. Accordingly, for such catalysts, it is desir-
able to have a Mg:Al atomic ratio more than 0.3:1, prefer-
ably from 0.5:1 to 10:1 and most preferably 0.6:1 to 7:1.
In suitable complexes, organometallic compounds (other than
AlR3, ZnR2 or mixtures thereof) which also solubilize the
organomagnesium compound in hydrocarbon are employed in
beneficial amounts, usually an amount su~ficient to produce
an atomic ratio of 0.01:1 to 10:1 of metal of the organo-
metallic compound to magnesium. Examples of such other
organometallic compounds include boron trialkyls such as
boron triethyl, alkyl silanes such as dimethyl silane and
tetraethyl silane.
Alternative to the aforementioned hydrocarbon
soluble complexes, it is also advantageous to employ
organomagnesium compounds as the organomagnesium compo-
nent. Such compounds, although conventionally insoluble
in hydrocarbon, are suitably employed. These compounds
can be rendered soluble in hydrocarbon by ways kno~n in
17,712-~ -6-
~56546
the art. The hydrocarbon solubilized organomagnesium
compounds which do not contain catalyst poisons are the
most desirable if an organomagnesium compound is to be
used as the organomagnesium component~
Preferably the organomaynesium compound is
dihydrocarbylmagnesium such as the magnesium dialkyls
and the magnesium diaryls. Exemplary suitable magnesium
dialkyls include dibutylmagnesium, dipropylmagnesium~
diethylmagnesium, dihexylmagnesium, propylbutylmagnesium
and others wherein alkyl has from 1 to 20 carbon atoms.
~xemplary suitable magnesium diaryls include diphenyl-
magnesium, dibenzylmagnesium, and ditolylmagnesium, with
the di~lkylmagnesiums such as dibutylmagnesium, being
especially preferred. Suitable organomagnesium compounds
include alkyl and aryl magnesium alkoxides and aryloxides
and aryl and alkyl magnesium halides with the halogen-free
organomagnesium compounds being more desirable.
In cases wherein the organomagnesium component
does not contain aluminum, it is sometimes desirable to
include in the total catalyst an aluminum compound such
as an alkyl aluminum compound, e.g., a trialkyl aluminum~
an alkyl aluminum halide or an aluminum halide such that
high~y active trialkyl aluminum or dialkyl aluminum halide
is available in small proportions as indicated herein-
before.
The active non-metallic halides of the formula
set forth hereinbefore include hydrogen halides and active
organic halides such as t-alkyl halides, allyl halides,
benzyl halides and other active hydrocarbyl halides wherein
17,712-F ~7~
ilL~565~6
hydrocarbyl is a monovalent hydrocarbon radical. By an
active organic halide is meant a hydrocarbyl halide that
contains a labile halogen at least as active, i.e., easily
lost to another compound, as the halogen of sec. butyl
chloride, preferably as active as t~butyl chloride.
In addition to the organic monohalides, it is understood
that organic dihalides, trihalides and other polyhalides
that are active as defined hereinbefore are also suitably
employed.
Examples of preferred active halides include
hydrogen chloride, hydrogen bromide, t-butyl chloride,
t-amyl bromide, allyl chloride, benzyl chloride, crotyl
chloride, methylvinyl carbinyl chloride, ~-phenylethyl
bromide, and diphenyl methyl chloride. Most preferred
are hydrogen chloride, t-butyl chloride, allyl chloride,
and benzyl chloride.
The organomagnesium component is preferably
reacted in hydrocarbon with the active non-metallic halide
by adding with stirring the halide to the hydrocarbon con-
taining the organomagnesium component. Alternatively, this
desired intermediate reaction product may be formed by
adding with stirring the organomagnesium component to the
active halide or by simultaneously adding and mixing the
halide and the organomagnesium component over a period of
~S time. The reaction between the organomagnesium component
and the active halide causes the formation of a finely
divided insoluble material. This intermediate reaction
product now contains hydrocarbon insoluble portions as
well as soluble portions. The amount of the halide added
11,712-F 8
~StiS46
to the organomagnesium component is sufficiGnt to provide
an atomic ratio of Mg:X as set forth hereinbefore. How-
ever, in instances wherein aluminum is present or is to be
subsequently employed in the preparation o~ the catalytic
reaction product, the amount o halide should not be in such
amounts as to produce significant amounts of monoalkyl
aluminum dihalide or similar catalyst deactivating agents.
The aforementioned intermediate reaction product
is then advantageously mixed with an amount of the transi-
tion metal compound, preferably by adding the transition
metal compound to the intermediate reaction product,
sufficient to provide a catalytic reaction product having
an atomic ratio of X:TM and Mg:TM as indicated herein-
before.
While the catalytic reaction product prepared
in the foregoing manner is especially preferred in the
practice of this invention, a ~eneficial catalytic re-
action product can be prepared by mixing the active
nonmetallic halide with the transition metal compound
to form an intermediate reaction product thereof and
subsequently reacting this intermediate product with
the organomagnesium complexO Also sui~able, but less
preferred, catalytic reaction products can be made by
first mixing the organomagnesium complex with the tran-
sition metal compound and then adding the active non~
metallic halide or by adding and mixing all three com-
ponents simultaneously.
In the preparation of the foregoing catalytic
reaction products, it is preferred to carry out such
17,71~-F ~9~
1~56546 `
preparation in the presence of an inert diluent. The
concentrations of catalyst components are preferably
such that when the active non-metallic halide, and the
magnesium complex are combined, the resultant slurry
is from 0.005 to 0.1 molar (moles/liter) with respect
to magnesium. By way of an example of suitable inert
organic diluents can be mentioned liquefied ethane,
propane, isobutane, n-bu~ane, n-hexane, khe various
isomeric hexanes, isooctane, paraf~inic mi~tures of
alkanes having from 8 to 9 carbon atoms, cyclohexane,
m~thylcyclopentane, dimethylcyclohexane, dodecane, in-
dustrial solvents composed of satura~ed or aromatic
hydrocarbons such as kerosene and naphthas especially
when freed of any olefin compounds and other impurities,
and especially those having boiling points in the range
from -50 to 200C. Also included as suitable inert
diluents are, for example, benzene, toluene, ethylben-
zene, cumene and decalin.
Mixing of the catalyst components to provide
the desired catalytic reaction product is advantageously
carried out under an inert atmosphere such as nitrogen,
argon or other inert gas at temperatures in the range
from -50 to 150C, preferably from 0 to 50C. The period
of mixing is not considered to be critical as it is found
that a sufficient catalys~ composition most often occurs
within 1 minute or less. In the preparation of the
catalytic reaction product, it is not necessary to sepa-
rate hydrocarbon soluble components from hydrocarbon
insoluble components of the reaction product. Further
1 ,712-F -10-
~05~546
it is not r~quired to add a cocatalyst or an activator
such as an alkyl aluminum compound to the catalytic
reaction product in order to obtain a high ef~iciency
catalyst. In fact, it is generally undesirable to add
any aluminum compound in excess o~ the amount~ prescribed
hereinbefore in order to retain high catalyst efficiency
at high polymerization temperatures.
In the polymerization process employing the
aforementioned catalytic reaction product, polymerization
is effected by adding a catalytic amount of the above
catalyst composition to a polymerization zone containing
~-olefin monomer, or vice versa. The polymerization
zone is maintained at temperatures in the range from
0 to 300C, preferably at solution polymerization tem-
peratures, e.g., from 150 to 250C for a residence time
of 10 minutes to several hours, preferably 15 minutes
to 1 hour. It is generally desirable to carry out the
polymerization in the absence of moisture and oxygen
and a catalytic amount of the catalytic reaction product
is generally within the range from 0.0001 to .01 milligram-
-atoms transition metal per liter of diluent. The most
advantageous catalyst concentration will depend upon
polymerization conditions such as tem~erature, pressure,
solvent and presence o~ catalyst poisons and that the
foregoing range is given to obtain maximum catalyst
yields. Generally in the polymerization process, a
carrier which may be an inert organic diluent or solvent
or excess monomer is generally employed. In order to
realize the full benefit of the high efficiency catalyst
1l,712-F -11-
l~S6S~
of the present invention care must be taken to avoid
over saturation of the solvent with polymer. If such
saturation occurs ~efore the catalyst becomes depleted,
the full efficiency of the catalyst is not realized.
For best results, it is preferred that the amount of
polymer in the carrier not exceed 50 weight percent based
on the total weight of the reaction mixture.
The polymerization pressures preferably employed
are relatively low, e.g., from 100 to 500 psig (70 to 350
kg~sq cm gauge). However, polymerization within the
scope of the present invention can occur at pressures
from atmospheric up to pressures determined by the ca~
pabilities of the polymerization equipment. During
polymerization it is desirable to stir the polymerization
recipe to obtain better temperature control and to main
tain uniform polymerization mixtures throughout the
polymerization zone.
In order to optimize catalyst yields in the
polymerization of ethylene, it is preferable to maintain
an ethylene concentration in the solvent in the range
from 1 to 10 weight percent, most advantageously 1.2
to 2 weight percent. To achieve this when an excess
of ethylene is fed into the system, a portion of the
ethylene can be vented.
Hydrogen is often employed in the practice
of this invention to lower molecular weight of the re-
sultant polymer. For the purpose of this invention,
it is beneficial to employ hydrogen in concentrations
ranging from 0.001 to 1 mole per mole of monomer. The
17,712-F -12-
~S~;S4~;
lar~er amounts of hydrogen within this range are found
to produce generally lower molecular weight polymers.
Hydrogen can be added with a monomer strearn to the poly-
merization vessel or separately added to the vessel be-
fore, during or after addition of the monomer to the
polymerization vessel, but during or before the addition
of the catalyst.
The monomer or mixture o~ monomers is contacted
with the catalytic reaction product in any conventional
manner, preferably by bringing the catalytic reaction
product and monomer to~ether with intimate agitation
provided by suitable stirring or other means. ~gitation
; can be continued during polymerization, or in some in-
stances, the polymerization can be allowed to remain
unstirred while polymerization takes place. In the case
of more rapid reactions with more active catalysts, means
can be provided for refluxing monomer and solvent, if
any of the latter is present and thus remove the heat
of reaction. In any event, adequate means should be
provided for dissipating the exothermic heat of poly-
merization. If desired, the monomer can be brought in
the vapor phase into contact with the catalytic reaction
product, in the presence or absence of liquid material.
The polymerization can be effected in the batch mannerr
or in a continuous manner, such as, for example, by
; passing the reaction mixture through an elongated reaction
tube which is contacted externally with suitable cooling
medium to maintain the desired reaction temperature,
or by passing the reaction mixture through an equili-
3~ brium overflow reactor or a series of the same.
17,712-F -13-
1~56S~6
The polymer is readily recovered from the
polymerization mixture by driving off unreacted monomer
and solvent if any is employed. No further removal of
impurities is required. Thus, a significant advantage
of the present invention is the elimination of the cata-
lyst residue removal steps. In some instances, however,
it may be desirable to add a small amount of a catalyst
deactivating reagent. The resultant polymer is ~ound to
contain insignificant amounts of catalyst residue and
to possess a very narrow molecular weight distribution.
The fallowing examples are given to i.llustrate
the invention. A11 parts and percentages are by weight
unless otherwise indicated.
In the following examples the catalyst prepara-
tions are carried out in the absence of oxygen or wa~er
in a nitrogen filled gloved box. The catalyst components
are used as diluted solutions in either n-heptane or
Isopar E (a mixture of saturated isoparaffins having
8 to 9 carbon atoms). The polymerization reactions are
carried out in a five liter stainless steel stirred batch
reactor at 150C unless otherwise stated. In such poly-
merization reactions two liters of dry oxygen-free Isopar
E are added to the reactor and heated to 150C. The
reactor is vent~d to about 25 psig (1.75 kg/sq. cm. gauge)
and 15-to 20 psi ~1.05 to 1.4 kg./sq. cm.) of hvdrogen is
added for polymer molecular weight control. Then, 120
psi (8.4 kg./sq. cm.) of ethylene is added to the reactor
and the ethylene pressure is set to maintain the reactor
17,712-F -14-
105654~;
pressure at 155 to 165 psig (10.9 to 11.6 kg./sq. cm.).
The catalyst is then pressured into the reactor using
nitrogen and the reactor temperature is maintained for the
desired polymerization time. The polymerization reactor
contents are dumped into a stainless steel beaker and
allowed to cool. The resulting slurry is filtered and the
polymer dried and weighed. The ethylene consumption during
polymerization is recorded with a DP cell which shows the
rate of polymerization and the amount of polymer produced.
Catalyst efficiencies are reported as grams of polyethyl-
ene catalyst per gram of titanium, g.PE/g.Ti.
Example 1
A catalyst is prepared by adding with stirring
0.946 ml of 0.519 M di(n-butyl)magnesium 2 triethylalumi-
num to a solution of 15 ml of 0.123 M anhydrous hydrogen
chloride in Isopar E . A white precipitate results
immediately upon addition of the magnesium complex.
To the resultant slurry are added 1.18 ml of 0.01 M
tetra(isopropoxy)titanium and 82.9 ml of Isopar E .
A 12.7-ml aliquot (0.0015 mmoles Ti) of this catalyst
is added to the polymerization reactor producing an
increase in temperature to 167C. After 30 minutes,
230 grams of linear polyethylene is formed to give a
catalyst efficiency of 3.2 x 10 g.PE/g.Ti.
Example 2
A catalyst is prepared by adding 93 ml of Isopar
E , 2.5 ml of 1.15 M t-butylchloride in Isopar E , 3.05
ml of 0.295 M di(n-butyl)magnesium 2 triethylaluminum
17,712-F -15-
l~S6~
to a 4 oz. bottle. To the resultant slurry is added
1.5 ml of O.al M tetra(isopropoxy)titanium. Ten milli-
liters of this catalyst (0O0015 mmoles Ti) is added to
the polymerization reactor and after 30 minutes the
reactor contents are dumped. The yield of polymer is
204 grams indicating a catalyst eficiency of 2.8 x 106
g.PE/g.Ti.
Example 3
_
To 247 weiyht parts of Isopar ER is added 133
weight parts of 0.516 M di(n-butyl)magnesium-2 aluminum
tri~thyl complex~ An 11.75 weight part portion of hy-
drogen chloride gas is added to the foregoing solution
of the complex with agitation~ The resultant slurry
is cooled to ambient temperature (~25C) and 322 ml of
neat tetra(isopropoxy)titanium is added. The result-
ing catalyst is diluted with Isopar ER to give 500 weight
parts of total catalyst. This catalyst is added continu-
ously to a 6900 gallon (26 cu meters) reactor along with
40,000 wt parts/hr of ethylene and Isopar E~. The amounts
of catalyst and Isopar ER are varied to maintain a reactor
temperature of at least 185C. Hydrogen is added to
the reactor to control molecular weight of the polymer
such that the polymer has a Melt Index of 2.5 to 12
decigrams per minute as determined by ASTM D-1238-65T
(Condition E). The catalyst efficiency of the foregoing
polymerization is greater than 1 X 106 g.PE/g.TiO
Example 4
To establish the improved stability of the
present catalyst at high temperature, three runs are
17,712-F -16-
lOS6S46
carried out employing catalysts which differ only as
to source of halide and concentration of aluminum.
In accordance with the present invention, a
catalyst is prepared by adding to 30.16 Kg. of Isopar
ER the following components:
311.85 g. of HCl gas
5.556 Kg. o~ 0~548M DBMg~2ATE* in Isopar ER
29.6 mls. (28.27g.) of neat tetra(isopropoxy)-
titanium
*di(n-butyl)magnesium-2 aluminum triethyl
The resulting catalyst has an atomic ratio as follows:
Cl/Mg/Al/Ti = 9O/31O5/59.5/1.
Following the general polymerization procedure in a 250
gallon (945 liter) stirred reaction vessel except employ-
ing a polymerization temperature of 185C, the foregoing
catalyst exhibits a catalyst efficiency of 1.07 x 106
g.PE/g.Ti.
For purposes of comparison, a catalyst is pre-
pared by adding to 25.54 kg. of Isopar ER the following
components:
- 6.01 Kg. of 15 p~rcent ethylaluminum dichloride
in Isopar E
6.69 Kg. of 0.548M DBMg-2ATE* in Isopar ER
31.5 mls. (30.08 g.) neat tetra~isopropoxy)-
titanium.
*ai (n~butyl)magnesium-2 aluminum triethyl
The resulting catalyst has an atomic ratio as follows:
Cl/Mg/Al/Ti = 134/40/147/1
Again following the foregoing general polymerization
procedure except for polymerization temperature two runs
using this catalyst are carried out at polymerization
17,712-F -17-
i~S65~6
temperatures of 150C and 170C. In these runs, the
catalyst exhibits catalyst efficiencies of 1.16 x 106
g.PE/g.Ti and 0.43 x 106 g.PE/g.Ti, respectivelyO In
- a similar run wherein a polymerization temperature of
185C is employed, no measurable amount o polyethylene
is produ~ed.
_ ample 5
As evidence of preferred order of addikion
of components in catalyst preparation, three runs are
carried out under similar conditions except that the
order of addition of components in preparation of the
catalyst differs from one run to another. The compo-
nents of the catalyst are as follows:
.0657 g. of HCl in 15 mls. of Isopar ER
,1726 g. of 0.51M DBMg-2ATE* in Isopar ER
.0039 g. of neat tetra(isopropoxy)titanium.
*di(n-butyl)magnesium-2 aluminum triethyl
Atomic ratio of the components is
Cl/Mg/A1/Ti = 130/40/80/1.
Polymerization is carried out according to thP procedure
of Example 4 using a polymerization temperature of 150C.
The r~sults are recorded in Table I.
7,712-F -18-
:~OS6546
TABLE I
Catalyst
Run Efficiency,(2)
No. Order of Addition (1) g.PE/g.Ti
1 HCl/DBMg-2ATE*/Ti(OiPr)4 2.0 x 10
2 HCl/Ti(OiPr)4/DBMg~2ATE* 0~98 x 106
3 DBMg-2ATE*/Ti(OiPr)4/HC1 0.68 x 10
(1) Components added to the catalyst reaction vessel
in left to right order. In Run No. 3, the mix-
ture of DBM~2ATE* ~ Ti(OiPr)4 is added to HCl
in Isopar E 1.
(2) Catalyst efficiency in grams of polyethylene
per gram of titaniuma
* di (n-butyl)magnesium-2 aluminum triethyl
Example 6
To illustrate the relation between Al:Ti and
Al:Mg ratios and catalyst efficiencies as temperature
increases, several runs are carried out using different
proportions of the following catalyst components:
anhydrous HC1
DBMg-x ATE*
tetra(isopropoxy)titanium
*di(n-butyl)magnesium-x al~inum triethyl wherein x
is a value between 1/6 and 2 obtained by combining
different amounts of DBMg-l/6 ATE and DBMg~2ATE.
in Isopar ERo The ratios of the foregoing catalyst
components are shown in Table II.
Following the polymerization procedure of EX-
ample 4 at a polymerization temperature as indicated
in Table II, ethylene is polymerized in the presence
of the several catalysts and the results are shown in
Table II.
17,712-F -19-
~S~i~46
TABLE II
Catalyst
Run Atomic Ratio, Polymerization Efficiency,
No. Cl/Mg/Al/Ti Temperature,C g.PE/g.Ti
1 134/40/58/1 185 1.8 x 106
2 90/40/58/1 185 }.0 x 106
3 90/40/40/1 189 1.0 x 106
4 90/40/~0/1 lg6 1.0 x 106
90/40/13.3/1 199 1.6 x 106
6 90/40/8/1 199 1.5 x 106
7 90/40/8/1 205 1.4 x 106
8 84O5/~0/6.25/1 212 1.1 x 106
As evidenced by the foregoing data of Example 4
and Table II, as polymerization temperature increases, the
ratio of Al~Mg and Al:Ti should be reduced in order to ob-
tain high catalyst efficiencies.
17,712-F -20-
