Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
6~i
--1--
HIGH EFFICIENCY CATALYST FOR POLYMERIZING OLEFINS
This invention relates to a new catalyst
composition useful for polymerization of ~-olefins and
to a polymerization process employing such a catalyst
composition.
It is well known that olefins such as ethylene,
propylene and l-butene in the presence of certain
metallic catalysts can be polymerized to form sub-
stantially unbranched polymers of relative]y high
molecular weight. Among the methods for producing such
linear olefin polymers, some of the most widely utilized
are those described by Professor Karl Ziegler in U.S.
Patents 3,113,115 and 3,257,332. In these methods, the
catalyst employed is obtained by admixing a compound of
a transition metal of Groups IVB, V, VIB and VIII of
Mendeleev's Period Table of Elements with an organo-
metallic compound. Generally, the halides, oxyhalides
and alkoxides or esters of titanium, vanadium and
zirconium are the most widely used transition metal
compounds. Common examples of the organometallic
compounds include the hydrides, alkyls and haloalkyls
of aluminum, alkylaluminum halides, Grignard reagen-ts,
alkali metal aluminum hydrides, alkali metal
27,760A-F
'7~i6
--2--
borohydrides, alkali metal hydrides, alkaline earth
metal hydrides and the like. Usually, polymerization
is car~ied out in a reaction medium comprising an inert
organic liquid, e.y., an aliphatic hydrocarbon and the
aforementioned catalyst. One or more olefins may be
brought in-to contact with the reaction medium in any
suitable manner. A molecular weight regulator, which
is normally hydrogen, is usually present in the reaction
vessel in order to suppress the formation of undesirably
high molecular weight polymers.
Most of the aforementioned known catalyst
systems are more efficient in preparing polyolefins in
slurry (i.e., wherein the polymer is not dissolved in
the carrier) than in solution (i.e., wherein the
temperature is high enough to solubilize the polymer in
the carrier). The lower efficiencies oF such catalysts
in solution polymerization is generally believed to be
caused by deactivation of such catalysts by the higher
temperatures employed in solution processes. In addition,
processes involving the copolymerization of ethylene
with higher ~-olefins exhibit catalyst efflciencies
significantly lower than ethylene homopolymerization
processes.
Recently, catalysts having higher efflcien-
cies have been disclosed, e.g., U.S. Patent 3,392,159;U.S. Patent 3,737,393; West German Patent Application
2,231,982 and ~ritish Patents 1,305,610 and 1,358,437.
While the increased efficiencies achieved by using
these recent catalysts are significant, even higher
efficiencies are desirable, particularly in copolymer-
ization processes. These high efficiency catalysts
generally produce polymers of relatively narrow molec-
27,760A~F -2-
~'7~
--3--
ular weigh-t distribution. But for certain uses, a
wider molecular weight range is desirable.
The present invention, in one aspect, is an
improvement in the cataly-tic reaction produc-t of (A) a
tetravalent titanium compound, (B) an organomagnesium
component, (C~ a halide source, and, if either components
(B) or (C) does no-t contain sufficient quantities of
aluminum, then (D) an alumlnum compound is also present;
the improvement being the use of, as the titanium
compound, a mixture containing a tetrahydrocarbylo~y
titanium compound and a dihydrocarbyloxy titanium
oxide. The molar ratio of the tetraalkoxy titanium
compound to dialkoxy titanium o~ide is 0.1.1 to 10:1,
preferably 0.2:1 to 5:1 and most preferably 0.33:1 to
1~ 3:1.
The magnesium component is (1) a complex of
an organomagnesium compound and an organometallic
compound which solubilizes the organomagnesium compound
in a hydrocarbon solvent or (2) an organomagnesium
compound. The proportions of the foregoing components
of said catalytic reaction produc-ts are such that the
atomic ratios of the elements are:
Mg:Ti is 1:1 to 200:1;
preferably 2:1 to 100:1;
most preferably 5:1 to 75:1;
Al:Ti is 0.1:1 to 1000:1;
preferably 0.5:1 to 200:1;
most preferably 1:1 to 75:1;
27,760~-F -3-
7~
~ .
excess X:AI is 0.0005:1 to 5:1;
preferably 0.001:1 to 2:1;
most preferably 0.01:1 to 1.4:1.
The X is excess halide above that which would
be theoretically re~uired to convert the magnesium
compound to the dihalide.
In a second aspect, the invention is a process
for polymerizing at least one ~-olefin or diolefin
under conditions characteristic of Ziegler polymeriza
tion wherein the aforementioned reaction product is
employed as the catalyst.
The present invention is most advantageously
practiced in a polymerization process wherein an
~-olefin or diolefin is polymerized, generally in the
presence of hydrogen as a molecular weight control
agent, in a polymerization zone containing an inert
diluent and the catalytic reaction product. Especially
advantageous is the copolymerization of ethylene and
higher ~-olefins or diolefins using the cataly-tic
reaction product of this invention. The process is
most beneficially carried out under inert atmosphere
and relatively low temperature and pressure, although
very high pressures are optionally employed.
Olefins which are suitably homopolymerized or
~5 copolymeriæed in the practice of this invention are
generally the aliphatic ~-monoolefins or ~-diolefins
having from 2 to 1~ carbon atoms. Illustratively~ such
~-olefins can include ethylene, propylene, butene-1,
pentene-1, 3-methylbutene-1, 4-methylpentene-1, hexene-1,
octene-1, dodecene-l, octadecene-1, and 1,7-octadiene.
27,760A-F -4-
7~
--5--
It is understood that ~olefins may be copolymerized
with other ~-olefins and/or with small amounts, i.e. up
to about 25 weight percent based on the copolymer, of
other ethylenically unsaturated monomers such as styrene,
5 u-methylstyrene and similar ethylenically unsaturated
monomers which do not destroy conventional Ziegler
catalysts. Most benefits are realized in the polymer-
ization of aliphatic ~-monoolefins, particularly
ethylene and mixtures of ethylene and up to 50,
especially from about 0.1 to 40, weight percent of
propylene, butene-1, hexene-l, octene-1, 4-methyl-
pentene-l, 1,7-octadiene or similar ~-olefin or
diolefin based on total monomer.
Advantageously, the titanium tetraalkoxide is
represented by the empirical formula Ti(OR)~I wherein
each R is independently an alkyl or an aryl group
having from 1 to 12, preferably from 2 to 10, carbon
atoms. Exemplary of such compounds include tetra-n-
-butoxytitanium, tetra(isopropoxy)titanium, and
tetraphenoxytitanium.
Advantageously, the dialkoxy titanium oxide
is represented by the empirical formula (Ro)~Tio wherein
each R is independently an alkyl or an aryl group
having 1 to 12, preferably 2 to 10, carbon atoms.
Exemplary of such compounds are diethyoxy titanium
oxide, diisopropoxy titanium oxide, di-n-butoxy
titanium oxide, diphenoxy titanium oxide, mixtures
thereof and the like.
The dihydrocarbyloxy titanium oxides employed
in the present invention can be prepared according to
the procedure described in THE O~GANIC C~E~ISTRY OF
27,760A-F -5-
-6-
TITANIUM, Raoul Feld & P. 0. Cowe, Butterwor-th & Co.
(Publishers) Ltd., 1965, page 141.
The preferred organomagnesium component is a
hydrocarbon soluble complex illustrated by the empir-
ical formula MgR"2-xMR"y wherein each R" is indepen-
dently hydrocarbyl or hydrocarbyloxy; M is aluminum,
zinc or mixtures -thereof; x is zero to 10, especially
zero to 2.5, and y denotes the number of hydrocarbyl
groups which corresponds to the ~alence of M. As used
herein, hydrocarbyl and hydrocarbyloxy are monovalent
hydrocarbon radicals. Preferably, hydrocarbyl is
alkyl, cycloalkyl, ar~l, aralkyl, alkenyl and similar
hydrocarbon radicals having 1 to 20 carbon atoms, with
alkyl having 1 to 10 car~on atoms being especially
preferred. Likewise, preferably, hydrocarbyloxy is
alkoxy, cycloalkyloxy, aryloxy, aralkyloxy, alkenyloxy
and similar oxyhydrocarhon radicals having 1 to 20
carbon atoms, with alkyloxy having 1 -to 10 carbon atoms
being preferred. Hydrocarbyl is preferred over
hydrocarbyloxy.
This complex is prepared by reacting particulate
magnesium, such as magnesium turnings, or magnesium
particles with about a stoichiometric amount of hydro-
carbyl or hydrocarbyloxy halide, illustrated as R'X.
The resulting MgR"2, if it is hydrocarbon insoluble,
can be solubilized by adding the organometallic
compound such as AlR"3 or mixtures thereof with ZnR"2.
The amount of organometallic compounds which is added
to the MgR"2 to form the organomagnesium complex should
be enough to solubilize a significant amount of MgR"2,
e.g., at least 5 weight percent of MgR"2. It is
preferred to solubilize at least 50 weight percent of
27,760A-F -~-
the MgR"2 and especially preferred to solubilize all
the MgR" 2 -
To obtain maximum catalyst efficiency atpolymerization temperatures above 180~C, it is desirable
to minimize the amount of aluminum in the complex as
well as in the total catalyst. Accordingly, for catalysts
having Al:Ti atomic ratios less than 120:1 it is desirable
to have a Mg:Al atomic ratio more than 0.3:1, preferably
0.5:1 to 10:1. In suitable complexes, organometallic
compounds (other than AlR"3 , ZnR"2 or mixtures thereof)
which also solubilize the organomagnesium compound in
hydrocarbon are employed in beneficial amounts, usually
an amount sufficient to produce an a-tomic ratio of
0.01:1 to 10:1 of metal of the organometallic compounds
to magnesium. Examples of such other organometallic
compounds include boron krialkyls such as boron triethyl,
alkyl silanes such as dimethyl silane and tetraethyl
silane, alkyl tin and alkyl phosphorous compounds.
Alternately to such solubilized magnesium
complexes, other organomagnesium compounds although
insoluble i~ hydrocarbons, are often suitably employed.
These compounds can be rendered soluble in hydrocarbon
by addition of ether, amine, etc., although such
solubilizing ayents often reduce the activity of the
catalyst. Recently, such compounds have been made
hydrocarbon soluble without such additives, e.g., as
taught in U.S. 3,646,231. Such hydrocarbon soluble
organomagnesium compounds are -the mos-t desirable if an
organomagnesium compound is to be used as the organo-
magnesium component.
27,76OA-F 7-
ki
-8-
Preferably the organomagnesium compound is a
hydrocarbon soluble dihydrocarbylmagnesium such as -the
magnesium dialkyls and the magnesium diaryls. Exemplary
suitable magnesium dialkyls include particularly
n-butyl-sec-butyl magnesium, diisopropyl magnesium,
di-n hexyl magnesium, isopropyl-n-butyl magnesium,
ethyl-n-hexyl magnesium, ethyl-n-butyl magnesium,
di-n-octyl magnesium and others wherein alkyl is from 1
-to 20 carbon atoms. Exemplary suitable magnesium
diaryls include diphenylmagnesium, dibenzylmagnesium,
and ditolylmagnesium, being especially preferred.
Suitable organomagnesium compounds include alkyl and
aryl magnesium alkoxides and aryloxides and aryl and
alkyl magnesium halides with the halogen-free organo-
magnesium compounds being more desirable.
Suitable organoaluminum compounds includethose represented by the empirical formula AlR3 aXa
wherein R is hydrocarbyl, hydrocarbyloxy or as herein-
before defined such as alkyl; X is a halogen and a is a
number from zero to 3. Most preferred are the aluminum
alkyls such as, for example, triethyl aluminum, triiso-
butyl aluminum, diethylaluminum chloride, diethyl-
aluminum bromide, mixtures thereof and the like.
It is understood tha-t the organic moieties of
2~ the aforementioned organomagnesium, e.g., R", and the
organic moieties of the halide source, e.g., R and R',
are suitably any other organic radical provided that
they do not contain functional 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
reagent.
27,760A-F -8-
,_g._
The halide source is suitably a nonmetallic
halide corresponding to the empirical formula R'X
wherein R' is hydrogen or an active monovalent organic
radical and X is halogen. Alternatively, the halide
source is a metallic halide corresponding to the empirical
Eormula MRy aXa wherein M is a metal of Group IIIA or
IVA of Mendeleev's Periodic Table of the Elements, R is
a monovalen~ organic radical, usually hydrocarbyl or
hydrocarbyloxy, X is halogen, y is a number corresponding
to valence of M and a is a number from 1 to y.
The preferred halide sources are the active
non-metallic halides of the formula set forth above
including hydrogen halides and active organic halides
such as t-alkyl halides, allyl halides, benzyl halides
and other active hydrocarbyl halides wherein hydro-
carbyl is as defined hereinbefore. By an active organic
halide it is meant a hydrocarbyl halide that contains a
halide atom at least as active, i.e., as easily los-t to
another compound, as the halogen of sec-butyl chloride,
and 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 non-metallic
halides include hydrogen chloride, hydrogen bromide,
t-butyl chloride, t-amyl bromide, allyl chloride,
benzyl chloride, crotyl chloride, methylvinyl carbinyl
chloride, ~-phenylethyl bromide, diphenyl methyl chloride,
t-butyl chloride, allyl chloride and benzyl chloride.
Suitable metallic halides as set forth by
formula hereinbefore are organometallic halides and
metal halides wherein the metal is in Group III~ or
27,760A-F -9-
-10-
IVA, of Mendeleev's Periodic Table of Rlements. Pre-
ferred metallic halides are aluminum halides of the
empiri~al formula AlR3 aXa wherein each R is indepen-
dently hydrocarbyl as hereinbefore defined such as
alkyl; X is a halogen and a is a number from 1 to 3.
Most preferred are alkylaluminum halides such as ethyl-
aluminum ses~uichloride, diethylaluminum chloride,
ethylaluminum dichloride and diethylaluminum bromide,
with ethylaluminum dichloride being especially preferred.
Alternatively, a metal halide such as aluminum tri-
chloride or a combination of aluminum trichloride with
an alkyl aluminum halide or a trialkyl aluminum compound
may be suitably employed.
In order to maximize catalyst efficiency, the
ca-talyst is prepared by mixing the components of the
catalyst in an inert liquid diluent in one of the
following especially preferred orders;
(1) A, D (if necessary), C and R;
(2) B, C, D (if necessary) and A;
(3) ~, C, A and D (if necessary and if C is not
a tin chloride);
(4) C, D (if necessary), A and B
with methods 2 and 3 being especially preferred. The
foregoing catalyst components are combined in propor-
tions sufficient to provide molar and atomic ratios as
previously mentioned.
The foregoing catalytic reaction is prefer-
ably carried out in the presence of an inert diluent.
The concentrations of catalyst componen-ts are prefer-
ably such that when the essential components of thecatalytic reaction product are combined, the resultant
slurry is 0.005 to 1.0 molar (moles/liter) with
27,760A-F -10-
respect to magnesium. By way of an example of suitable
inert organic diluents can be men-tioned liquefied
ethane~ propane, isobutane, n-butane, n-hexane, the
various isomeric hexanes, isooctane, paraffinic mixtures
of alkanes haviny from 8 to 12 carbon atoms, cyclohexane,
methylcyclopentane, dimethylcyclohexane, dodecane,
2,2,4-trimethylpentane industrial solvents composed of
saturated or aroma-tic hydrocarbons such as kerosene,
naphthas, etc., especially when freed of any olefin
compounds and other impurities, and especially those
having boiling points in the range from 50C to
200C. Also included as suitable inert diluents are
benzene, toluene, ethylbenzene, cumene, decalin and the
like.
Mixing of the catalyst components to provide
the desired catalytic reaction product is advanta~
geously carried out under an inert atmosphere such as
nitrogen, argon or other inert gas at temperatures in
the range from ~100C to 200C, preferably 0C to
100C. The period of mixing is not considered to be
critical as it is found that a sufficient catalyst
composltion most often occurs within 1 minute or
less. In the preparation of the catalytic reaction
product, it is not necessary to separa-te hydrocarbon
soluble components from hydrocarbon insoluble com-
ponents of the reaction product.
If desired, the catalytic reaction product of
this invention may also contain a dialkyl zinc compo-
nent wherein the alkyl groups are the same or different
and contain from 1 to 10 carbon atoms. Suitable such
dialkyl zinc compounds include, for example, diethyl
zinc, diisopropyl zinc, di-n-propyl zinc, di-n butyl
27,760A-F -11-
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-~2-
zinc, di sec-butyl zinc, mix-tures thereof and the like.
Such zinc compounds tend to provide polymers of broadened
molecu~ar weight distribution, as taught ln U.S. Patent
4,238,355.
In the polymerization process employing the
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 temperatures,
e.g., from 130C to 250C for a residence time of
a few seconds to several days, preferably 1~ seconds to
2 hours. 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 about 0.001 to 0.1
millimoles titanium per liter of diluent. It is under-
stood, however, that the most advantageous catalyst
concentration will depend upon polymerization conditions
such as temperature, pressure, solvent and presence of
catalyst poisons and that the foregoing range is given
to obtain maximum catalyst yields in weight of polymer
per unlt weight of titanium. Generally in the poly
merization 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 of the present
invention, care must be taken to avoid oversatura-tion
of the solvent with polymer. If such saturation occurs
before the catalyst becomes depleted, the full efficiency
of the catalyst ls not realized. For best results, it
is preferred that the amount of polymer in the carrier
27,760A-F -12-
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-13-
not exceed about 50 weight percent based on the total
weigh-t of the reaction mixture.
The polymeri2ation pressures preferably
employed are relatively low, e.g., from 0.~5 to 7.1 MPa
(50 to 1000 psig), especially from 0.8 to 5.0 MPa ~100
to 600 psig). However, polymerization within the scope
of the present invention can occur at pressure from
atmospheric up -to pressures determined by the capabilities
of the polymerization eguipment. During polymerization
it is desirable to stir the polymerization recipe to
obtain better temperature control and to maintain
uniform polymerization mixtures throughout the polymer-
ization zone.
In order to optimize catalyst yields in the
polymerization of ethylene, it is preferable to main-
tain an ethylene concentration in the solvent in the
range from about 1 to 10 weight percent, most advan-
tageously 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 can be employed in the practice of
this invention -to alter the molecular weight of the
resultant polymer. For the purpose of this invention,
it i5 beneficial to employ hydrogen in concentrations
ranging from 0.001 to 1 mole per mole of monomer. The
larger amounts of hydrogen within this range are found
to pro~uce generally lower molecular weight polymers.
It is understood that hydrogen can be added with a
monomer stream to the polymerization vessel or separately
added to the vessel before, during or after addition of
the monomer to the polymerization vessel, but during or
before the addition of the catalyst.
27,760A-F -13-
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-14-
The monomer or mixture of monomers is con-
tacted with the catlytic reaction product in any con-
ven-tional manner, preferably by bringing the catalytic
reaction product and monomer together with intimate
agitation provided by suitable stirring or other means.
Agitation can be continued during polymerization, or in
some instances, the polymerization can be allowed to
reamin unstirred while the 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
removing the heat of reaction. In any event adequate
means should be provided for dissipa-ting the exothermic
heat of polymerization. If desired, the monomer can be
brought in the vapor phase into contact with the catalytic
reaction product, in the presence or abs~nce of liquid
material. The polymerization can be effected in the
batch manner, 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 mi~ture
through an equilibrium overflow reactor or a series of
the same.
The polymer is readily recovered from the
polymerization mixture by driving off unreac-ted 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
catalyst residue removal steps. In some instanc~s,
however, i-t may be desirable to add a small amount of a
catalyst deactivating reagent of the types conven-tion~
ally employed for deactivating Ziegler catalysts. The
27,760A-F -14-
'7~
-15
resultant polymer is found to contain insignificant
amounts of catalyst residue and to possess a relatively
bxoad molecular weight distribution.
The following examples are given to illus-
trate the invention. All parts and percentages are byweight unless otherwise indicated.
The following atomic weight values were
employed in the examples to calculate the ratios of the
components.
10Al = 26.98Mg = 24.31
C = 12.01 O = 16.00
Cl = 35.45Ti = 47.90
H = 1.01
In the following examples and comparative
experiments, the melt index values I2 and I1o were
determined by ASTM D 1238-70 and the density values
were de-termined by ASTM D 1248.
COMPARATIVE EXPERIMENT A
A. Preparation of the dihydrocarbyl_xytitanium oxide
To 14.88 ml of 0.336 M Ti(OiPr)4 are added,
with intense stirring, 0.09 ml of deionized and deoxy-
genated water. After allowing 1 -to 2 minutes for
reaction, 85.03 ml of 2,2,4-trimethylpentane was added
to bring the total volume to 100.0 ml. This results in
a 0.05 M solution of the diisopropoxytitanium oxide.
The resulting reaction produc-t is a slurry of ra-ther
coarse particles. All component mixing was accom-
plished at ambient temperature.
27,760A-F -15-
~ ~1'7~
-16-
B. Preparat.ion of the Catalyst Composition
The catalyst composition was prepared by
adding,with stirring under a nitrogen atmosphere to a
120-ml serum bottle the following components in the
indicated order:
97.98 ml of 2,2,4-trimethylpentane
0.75 ml of 1.00 M ethylaluminum dichloride (EADC)
in 2,2,4-trimethylpentane
0.30 ml of 0.050 M diisopropoxytitanium oxide
(Ti(OiPr) 2 O) in 2,2,4-trimethylpentane
0.97 ml of 0.62 M butyl ethyl magnesium in
2,2,4-trimethylpentane
The temperature of the serum bottl~ was
maintained at ambient temperature (22C) and the reaction
was observed to be complete within 5 minutes.
The atomic ratios in -the catalyst components
were as follows:
Mg/Ti = 40/1
Al/Ti = 50/1
excess Cl/Al = 0.40/1.
C Pu~-r ~ D
Two liters of 2,2,4-trimethylpentane are
added to a one-gallon, stirred batch reactor and heated
to 150C. To this is added 0.06 MPA (9 psig) of hydrogen,
0.90 MPa (130 psig) of ethylene, and 5 ml (0.00075
mMole Ti) of the above catalyst. The,temperature was
controlled at 150C and the ethylene pressure was held
constant during the total reaction time of 30 minutes.
The catalyst yielded 135 gms of polymer for an efficiency
of 3.76 x 106 wt. of polyethylene per wt. of titanium.
27,760A-F -16-
-17-
The polyrner has an I2 melt index of 2.22, and I1o melt
index of 19.08, an l1o/I2 ratio of 8.59, and a density
of 0.9632.
EXAMPLE 1
~. Preparation of the Catalyst Composition
The catalyst components were added to a
120 ml serum bot-tle in the following order with stirring
under a nitrogen atmosphere:
97.91 ml of 2,2,4-trimethylpentane
0.75 ml of 1.00 M E.~DC in 2,2,4-trimethylpentane
0.225 ml of 0.050 M Ti(OiPr)2O in
2,2,4-trimethylpentane
0.97 ml of 0.62 M butyl ethyl magnesium in
2,Z,4-trimethylpentane
0.15 ml of 0.025 M tetraisopropoxy titanium
(Ti(OiPr)~) in 2,2,4-trimethylpentane
The molar ratio of Ti(OiPr) 2 : Ti(OiPr)~ = 3:1.
The atomic ratios of the catalyst componen-ts
were as follows:
Mg/Ti - 40/1 Al/Ti = 50/1
excess Cl/Al = 0.40/1
B. Polymeri~ation
Employing the procedure of Comparative Exper-
iment A, 5 ml (O.00075 ~Mole Ti) of this catalyst
yielded 168 gms of polymer for a catalyst efficiency of
4.68 x 106 wt. of polyethylene per wt. of titanium.
The polymer had an I2 melt index of 1.21, an I1o melt
index of 11.73, a I1o/I2 ratio of 9.69 and a density of
0.9622.
27,760A F -1'7-
XAMPLE 2
A. Preparation of the catalyst comPosition
, The catalyst components were added to a
120-ml serum bottle in the following order wi-th stirring
under a nitrogen atmosphere:
97.76 ml of 2,2,4-trimethylpentane
0.75 ml of 1.00 M EADC in 2,2,4-trimethylpentane
0.075 ml of 0.050 M Ti(OiPr)~O in
2,2,4-trimethylpentane
0.97 ml of 0.62 M butyl ethyl magnesium in
2,2,4-trimethylpentane
0.45 ml of 0.025 M Ti(OiPr)4 in
2,2,4-trimethylpentane
The molar ratio of Ti(OiPr) 2 : Ti(OiPr) 4 =
15 0.33:1.
The atomic ratios of the catalyst components
were as follows:
Mg/Ti = 40/1
Al/Ti = 50/l
excess Cl/Al = 0.40/1
B. Polymerization
Employing -the procedure of Comparative Exper-
iment A, 5 ml (0.00075 mMole Ti) of this catalyst
yielded 182 gms of polymer for a catalyst efEiciency of
5.07 x 106 wt. of polyethylene per wt. of titanium.
The polymer had an I2 melt index of 1~20, an I1o melt
index of 12.17, a I1o/I2 ratio of 10.14 and a density
of 0.9619.
27,760A-F -18-
~ ~'7l~ti~
--19--
EXAMPLE_
A. Preparation of the catalyst composition
, The catalyst components were added to a
120-ml serum bottle in the following order with stirring
under a nitrogen a-tmosphere:
97.83 ml of 2/2,4-trimethylpentane
O.75 ml of 1.00 M EADC in 2,2,4-trimethylpentane
0.15 ml of 0.050 M Ti(OiPr)2O in
2,2,4-trimethylpentane
0.97 ml of 0.62 M butyl ethyl magnesium in
2,2,4-trimethylpentane
0.30 ml of 0.025 M Ti(OiPr)4 in
2,2,4-trimethylpentane
The molar ratio of Ti(OiPr)2O:Ti(OiPr)4 = 1:1.
The atomic ratios of the catalyst componen-ts
were as follows:
Mg/Ti = 40/1
Al/Ti = 50/1
excess Cl/Ti = 0.40/1
B. Polymerlzation
Employing the procedures of this catalyst,
5 ml (0.00075 mMole Ti) of this catalyst yielded
173.9 gms of polymer for a catalyst efficiency of
4.84 x 106 wt. of polyethylene per wt. of titanium.
The polymer had an I2 melt index of 2.04, an I1o mel-t
index of 18.95, a I1o/I2 ratio of 9.29 and a density of
0.9627.
27,760A-F -19-
-20-
COMPARATIVE EXPERIMENT B
A. Preparation of the catalyst composition
, The catalyst components were added to a
120 ml serum bottle in the following order with stirring
under a nitrogen atmosphere:
97.68 ml of 2,2,4-trimethylpentane
O.75 ml of l.00 M EADC in 2,2,4-trimethylpentane
0.60 ml of 0.025 M Ti(OiPr)4 in
2,2,4-trimethylpentane
0.97 ml of ~.62 M butyl ethyl magnesium in
2,2,4-trimethylpentane
The atomic ratios of the catalyst components
were as follows:
Mg/Ti = 40/1
Al/Ti = 50/1
excess Cl/Ti = 0.40/1
B. Polymerization
Employing the same procedure of Comparative
Experiment A, 5 ml (0.00075 mMole Ti) of this catalyst
yielded 138.3 gms of polymer for a catalyst efficiency
of 3.85 x 106 wt. polymer per wt. of titanium.
These examples and comparative experiments
demonstrate that mixtures of Ti(OiPr)~ with the
Ti(OiPr) 2 O interact synergistically to produce catalyst
efficiencies higher than either component individually.
27,760A-F -20-
