Note: Descriptions are shown in the official language in which they were submitted.
17~22~
HIGH EFFICIENCY CATALYST CONTAINING TITANIUM
AND ZIRCONIUM A~D PROCESS FOR POLYMERIZING OLEFINS
This invention relates to a new catalyst
composition useful for initiating and promoting polymer-
ization 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 metallic
catalysts, particularly the reaction products of organo-
metallic compounds and transition~metal compounds, can
be polymerized to form substantially unbranched polymers
of relatively high molecular weight. Typically such
polymerizations are carried out at relatively low
temperatures and pressures. ~ ~
Among the method~ for producing~such linear
~: olefin polymers, some of the most widely utilized are
: 15 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, VB, VIB and VIII of
: Mendeleev's Periodic Table o~ Elements with an organo-
metallic compound. Generally, the halides, oxyhalides
and alkoxides or esters of titanium, vanadium and
27,723A-F
-2- ~17422~
zirconium are the most widely used transition metal
compounds. Common examples of the organometallic
compounds include the h~drides, alkyls and haloalkyls
of aluminum, alkylaluminum halides, Grignard reagents,
alkali metal aluminum hydrides, alkali metal boro-
hydrides, alkali metal hydrides, alkaline earth metal
hydrides and the like. Usually, polymerization is
carried out in a reaction medium comprising an inert
organic liquid, e.g., an aliphatic hydrocarbon and the
aforementioned catalyst. One or more olefins may be
brought into contact with the reaction medium in any
suitable manner. A molecular weight regulator, which
is normally hydro~en, is usually present in the reaction
vessel in order to suppress the formation of undesirably
high molecular weight polymers.
Following polymerization, it is common to
remove catalyst residues from the polymer by repeatedly
treating the polymer with alcohol or other deactivating
agents such as aqueous base. Such catalyst deactivation
and/or removal procedures are expensive both in time
and material consumed as well as the e~uipment required
to carry out such treatment.
Furthermore, most of the aforementioned known
catalyst systems are more efficient in preparing poly-
olefins ln slurry (i.e., wherein the polymer is notdissolved in the carrier) than in solution (i.e.,
wherein the temperature is high enough to solubilize
the poIymer in the carrier). The lower efficiencies of
such catalysts in solution polymerization is believed
to be caused by the general tendency of such catalysts
to become rapidly depleted or deactivated by the sig-
nificantly higher temperatures that are normally employed
in solution processes. In addition, processes involving
27,723A-F -2-
-3~ 2 2 ~
the copolymerization of ethylene with higher ~-olefins
exhibit catalyst efficiencies significantly lower than
ethylene homopolymerization processes.
Recently, ~atalysts having higher efficiencies
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 British 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 ef~iciency catalysts
generally produce polymers o~ relatively narrow molecular
weight distribution. It i5 therefore desirable to
have, for some applications such as injection molding,
lS high efficiency catalysts which produce polymers and
copolymers having a broader molecular weight distri-
bution and are sufficiently active at solution poly-
merization temperatures above 140C to produce high
yields of olefin homopolymers or copolymers per unit of
~0 catalyst without the necessity of further treatment to
remove catalyst residue to obtain a poIymer o~ desired
purity.
The present in~ention, in one aspect, is a
process for polymerizing ~-ole~ins under conditions
characteristic of Ziegler polymerization in the presence
of a catalyst prepared by reacting trivalent or tetra-
valent titanium compounds such as a titanium trichloride
or a titanium tetraalkoxide, zirconium compounds such
as tri-n-butoxy zircon~um chloride, an organomagnesium
component such as di-n-hexyl magnesium, a halogen
source such as ethyl aluminum dichloride and an organo-
aluminum compound if the halide source or magnesium
27,723A-F -3-
'4~ 4 2 2 ~
component does not contain sufficient quantities of
aluminum.
More specifically, the catalyst is the catalytic
reaction product of (A) a trivalent or tetravalent
titanium compound or mixture of such compounds, (B) a
zirconium compound or mixture of such compounds, (C) an
organomagnesium component and (D) a halide source. If
components (C) and/or (D) do not contain sufficient
quantities of an aluminum compound, then additional
quantities of an organoaluminum compound should be
added. The magnesium component is (l) a complex of an
organomagnesium compound and an organometallic compound
which solubilizes the organomagnesium compound or (2) a
hydrocarbon soluble organomagnesium compound. The
halide source is a non-metallic halide corresponding to
the empirical formula R'~ where in R' is hydrogen or an
active mo~ovalen~ organic radical and X is halogen.
Alternatively, the halide source is a metallic halide
corresponding to the empirical formula MRy aXa wherein
M is a metal of Group IIIA or IVA of Mendeleev's Periodic
Table of the Elements, R is a monovalent organic radical,
usually hydrocarbyl or hydr~carbyloxy, X is halogen, y
is a number corresponding to valence of M and a is a
number from 1 to y. The proportions of the foregoing
components of said catalytic reaction products are such
that the atomic ratios of the elements are:
Mg:Zr is from about 1:1 to about 100:1;
preferably from about 2.5:1 to about 50:1;
most preferably from about 5:1 to about 25:1;
~l:Zr is from about 0.1:1 to about 100:1;
preferably from about 0.5:1 to about 50:1;
most preferably from about 1:1 to about 25:1;
27,723A-F -4-
.
~ 1~4~2~
--5
Zr:Ti is from about 0.1:1 to about 50:1;
preferably from about 0.5:1 to about 40:1;
most preferably from about 1:1 to about 20:1;
excess X:Al is from about 0.0005:1 to about
10:1; preferably from about 0.002:1 to about
2:1; most preferably from about 0.01:1 to
about 1.4:1.
The excess X is excess halide above that
which would be theoretically required to convert the
1~ magnesium compound to the dihalide.
In view of the reduc~d activity of conven-
tional Ziegler catalysts in the copolymerization of
~-olefins, particularly at solution polymerization
temperatures, it is indeed surprising that the afore-
mentioned catalytic reaction product is a high efficiencycatalyst capable of producing more than a million parts
by weight of olefin polymer or copolymer per part of
transition metal under such polymerization conditions.
Accordingly, olefin polymers produced by this process
generally contain lower amounts of catalyst residues
than polymers produced in the presence of conventional
catalyst even after subjecting such conventionally
produced polymers to catalyst removal treatments.
Further, these catalytic reaction products provide
polymers produced therefrom with a relatively broader
molecular weight distribution and, at higher zirconium
amounts, a lower melt index than do corresponding
catalysts without the zirconium compounds.
The catalyst formulations of the present
invention are usually a dilute dark brown slurry of
very fine particles. The MgClz present is a fine,
27,723A-F -5-
` -6~ 4 2 2 ~
whitish precipitate with a surface area of about 250
m2/gm. The ZrCl4 exhibits a wide range of particle
size. If an alcohol is present, the solid 2rCl4 dis-
solves, presumably to a compound of the general formula
Zr(OR)xCly, with 0 < x < 4 and o < y < 4. The exact
structure of the Zr-Ti catalyst complex is not known.
The present invention is most advantageously
practiced in polymerization of an a-olefin, generally
in the presence of hydrogen as a molecular weight
control agent, in a polymerization zone containing an
inert diluent and the described catalytic reaction
product. Especially advantageous is the copolymer-
ization of ethylene and higher ~-olefins using the
catalytic reac~ion product of this invention. This
process is most beneficially carried out under inert
atmosphere and relatively low pressure, although very
high pressures are optionally employed.
Olefins which are suitably homopolymeriæed or
copolymerized in the practice of this invention are
generally the aliphatic ~-monoolefins or non-conjugated
~-diolefins having from 2 to 18 carbon atoms. Illus-
tratively, such ~-olefins can include ethylene, propylene,
butene-l, pentene-l, 3-methylbutene-l, 4-methylpentene~1,
hexene-1, octene-1, dodecene-1, octadecene-1, 1,4-hexadiene,
and 1,7-octadiene. 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 polymer, of othex ethylenically unsaturated monomers
such as s~yrene, ~-methylstyrene and similar ethylenically
unsaturated monomers which do not destroy conventional
Ziegler catalysts. Most benefits are realized in the
polymerization of aliphatic ~-monoolefins, particularly
ethylene and mi~tures of ethylene with up to S0, especially
27,723A-F -~-
-7- ~17~22~
from about 0.1 to about 40, weight percent of propylene,
butene-1, hexene-1, octene-1, 4-methylpentene-1,
1,4-hexadiene, 1,7-octadiene or similar ~-olefin or
non-conjugated ~-diolefin based on total monomer.
As used herein, hydrocarbyl and hydrocarbyloxy
are monovalent hydrocarbon radicals. Preferably,
hydrocarbyl is alkyl, cycloalkyl, aryl, aralkyl, alkenyl
and similar hydrocarbon radicals having 1 to 20 carbon
atoms, with alkyl having 1 to 10 carbon atoms being
especially preferred. Likewise, preferably, hydro-
carbyloxy is alkoxy, cycloalkyloxy, aryloxy, aralkyloxy,
alkenyloxy and similar oxyhydrocarbon radicals having 1
to 20 carbon atoms, with alkyloxy having 1 to 10 carbon
atoms being preferred.
Advantageously, the tetravalent titanium
compound has the formula: TiXn(OR)4_n ~ wherein X is a
halogen, particulary chlorine or bromine, R is a hydro-
carbyl group having from 1 to 20, preferably from 1 to
10 carbon atoms, and n has a value of 0 to 4O Such
titanium compounds are preerably derived fLom the
titanium halides wherein one or more o the halogen
atoms are replaced by an alkoxy or aryloxy group.
Exemplary of such compounds include tetra-n butoxy
titanium, tetra(isopropoxy) titanium, di-n-butoxy
titanium dichloride, monoethoxy titanium trichloride,
and tetraphenoxy titanium.
Suitable trivalent titanium compounds include
~- and y-TiCl3 and the trivalent titanium complexes
represented by the empirical formula: TiZ3(L)X wherein
Z is halide, and L is an electron donating compound
such as water or an organic electron donor, e.g.,
alcohol, ether, ketone, amine, or olefin, and x is a
27,723A-F -7-
-8- ~1 7422~
whole number from 1 to 6. Usually, the organic electron
donor has from 1 to 12 carbon atoms and donates an
unshared pair of electrons to the complex. Exemplary
electron donating compounds suitably employed include
aliphatic alcohols, e.g., isopropyl alcohol, ethanol,
n-propyl alcohol, butanol and others having from 1 to
12 carbon atoms; ethers; ketones; aldehydes; amines;
olefins, and the like having from 1 to 20 carbon atoms;
and water. In preferred complexes, Z is chloride or
bromide, most preferably chloride, and L is alcohol,
especially an aliphatic alcohol having 2 to 8 carbon
atoms and most preferably 3 to 6 carbon atoms, such as
isopropyl alcohol, n-propyl alcohol, n-butyl alcohol
and isobutyl alcohol. While the exact structure of the
complex is not known, it is believed to contain 3
valence bonds to the halide ions and 1 to 6, preferably
2 to 4, coordination bonds to the electron donating
compound. In addition to a TiCl3, the ~, y and ~
crystalline forms of titanium trichloride are advantag-
eously employed in the preparation of the complex.Also suitable are titanium tribromide, titanium fluoride
and the like. Of the foregoing, the y- and ~- forms of
titanium trichloride are preferred. These complexes
and their preparation are more fully described by
Birkelbach in U.S. Patent 4,120, a20 .
Suitable zirconium compounds are those having
the formula: ZrXn(OR)~ n~ wherein each R is independently
a hydrocarbyl group having from 1 to 20, preferably 1
to 10, carbon atoms, each X is independently a halogen
atom, preferably chlorine or bromine, and n has a value
from zero to 4.
Particularly suitable zirconium compounds
include, for example, ZrCl4, ZrBr4, Zr(OnBu) 4, Zr(OnPr) 4,
27,723A-F -8-
~ ~7~2~
Zr(OEt)2Cl2, Zr(OEt)2Br2 Zr(OnPr)2Cl2, Zr(OnPr)2Br2,
Zr(OiPr)2Cl2, Zr(OiPr)2Br2, Zr(OnBu)2Cl2, Zr(OnBu)2Br2,
mixtures thereof and the like. In the above formulae,
Et = ethyl, iPr = isopropyl, nPr = normal propyl, and
nBu = normal butyl.
The zirconium compounds represented by the
empirical formula Zr(OR)xXy wherein 0 _ x < 4 can be
prepared in situ by adding a zirconium tetrahalide and
an aliphatic alcohol having from 1 to abou~ 20, preferably
1 to about 10, carbon atoms to the catalytic reaction
mixture as the zirconium component. The mole ratio of
alcohol to zirconium halide is from about 0.01 to about
10, preferably from about 0.25 to about 4.
A preferred organomagnesium component is a
hydrocarbon soluble complex illustrated by the empirical
formula MgR"2-xMR"y wherein R" is independently hydro-
carbyl or hydrocarbyloxy, M is aluminum, zinc, boron,
silicon, tin, phosphorous or mixtures thereof, x is
about zero to 10, especially from about zero to about
0~25, and y denotes the number of hydrocarbyl groups
which corresponds to the valence of M. 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. Accordingly, for catalysts having
Al:Ti atomic ratios less than 1~0:1, it is desirable to
have a Mg:Al atomic ratio more than 0.3:1, preferably
from about 0.5:1 to 10:1.
Preferably the organomagnesium compound is a
hydrocarbon soluble dihydrocarbylmagnesium such as the
magnesium dialkyls and the magnesium diaryls. Exemplary
suitable magnesium dialkyls include particularly
27,723A-F 9
-lo- ~17422~
n-butyl-sec-butyl ma~nesium, 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 each alkyl has
from 1 to 20 carbon atoms. Exemplary suitable magnesium
diaryls include diphenylma~nesium, dibenzylmagnesium
and ditolylmagnesium. 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.
The preferred halide sources are the active
non-metallic halides of the ~ormula set forth herein-
before including hydrogen halides and active organic
halides such as t-alkyl halides, allyl halides, ben~yl
halides and other active hydrocarbyl halides wherein
hydrocarbyl is as defined hereinbefore. By an active
organic halide is meant a hydrocarbyl halide that
contains a labile halogen at least as active, i.e., as
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 herein-
before 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, a phenylethyl bromide,
and diphenyl methyl chloride.
Suitable metallic halides as set forth by
formula hereinbefore are organometallic halides and
metal halides wherein the metal is in Group IIIA or IVA
of Mendeleev's Periodic Table of Elements. Preferred
27,723A-F -10-
~ 1742~
--11--
metallic halides are aluminum halides of the empirical
formula AlR3 aXa wherein each R is independently hydro-
carbyl 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 ethylaluminum sesqui-
chloride, diethylaluminum chloride, ethylaluminum
dichloride, and diethylaluminum bromide, with ethyl-
aluminum dichloride being especially preferred. Alterna-
tively, a metal halide such as aluminum trichloride or
a sombination of aluminum trichloride with an alkyl
aluminum halide or a trialkyl aluminum compound may be
suitably employed.
It is understood that the organic moieties of
the organomagnesium compound, 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.
For ease of catalyst preparation the catalyst
is pr~pared by mixing the components of the catalyst in
an inert liquid diluent in the following order:
(1) the halide source (D), (2) the aluminum compound (E)
if necessary, (3) the titanium compound (A), (4) the
zirconium compound (B) and (5) the oxganomagnesium
component (C). It is understood, however, that any
suitable order of addition can be employed as long
as the titanium and/or zirconium compound is not
over-reduced by the other catalyst components (over-
-reduction is evidenced by a drastic drop in catalyst
efficiency or total inactivity of the catalyst).
27,723A-F -11-
-12- ~7~22~
These catalyst components are combined in
proportions sufficient to provide atomic ratios as
indicated.
In cases wherein neither the organomagnesium
component nor the halide source contains aluminum, it
is necessary 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. If polymerization temperatures below
180C are employed, the atomic ratios of Al:Ti may be
from about 0.1:1 to about 2000:1, preferably from l:l
to 200:1. However, when polymerization temperatures
above 180C are employed, the aluminum compound is used
in proportions such that the Mg:Al ratio is more than
0.3:1, preferably from 0.5:1 to 10:1, and Al:Ti ratio
is less than 120:1, preferably less than 50:1. The use
of very low amounts of aluminum necessitates the use of
high purity solvents or diluents and the other components
should be essentially free of impurities which react
with aluminum alkyls. Otherwise, additional quantities
of an organometallic compound as previously described,
preferably an organoaluminum compound, must be used to
react with such impurities. Moreover in the catalyst
the aluminum compound should be in the form of trialkyl
aluminum or an alkyl aluminum halide substantially free
of alkyl aluminum dihalide.
Preparation of the catalyst is preferably
carried out in the presence of an inert diluent. The
concentrations of catalyst components are preferably
such that when the essential components of the catalytic
reaction product are combined, the resultant slurry is
from about 0.0005 to about 1.0 molar (moles/liter) with
27,723A-F -12-
-13- ~ 17~22~
respect to magnesium. Suitable inert organic diluents
include liquefied ethane, propane, isobutane, n-butane,
n-hexane, the various isomeric hexanes, isooctane,
paraffinic mixtures of alkanes having from 8 to 12
carbon atoms, cyclohexane, methylcyclopentane, dimethyl-
cyclohe~ane, dodecane, industrial solvents composed of
saturated or aromatic 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 about -~0 to
200C. Also included as suitable inert diluents are
benzene, toluene, ethylbenzene, 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 about -100 to about 200C, preferably from about
0 to about 100C. The period of mixing is not critical
as formation of the catalyst composition most often
occurs within 1 minute or less. In the prepara~ion of
the catalytic reaction product, it is not necessary to
separate hydrocarbon soluble components from hydro-
carbon insoluble components of the reaction product.
ln the polymerization process employing the
aforementioned catalytic reaction product, polymeri-
zation is effected by adding a catalytic amount of the
above catalyst composition to a polymerization zone
containing ~-olefin monomer, or vice versa. The poly-
merization zone is maintained at temperatures in the
range from about 0 to 300C, preferably at solution
polymerization temperatures, e.g., from about 130 to
250C, for a residence time of a few seconds to several
27,723A-F -13-
-14- ~7~27
days, preferably 15 seconds to 2 hours. It is generally
desirable to carry out the polymerization in the absence
of moisture and oxygen with a catalytic amount of the
catalytic reaction product being within the range from
S about 0.0001 to about 0.1 millimoles titanium per liter
of diluent. The most advantageous catalyst concentration
will depend upon polymerization conditions such as
temperature, pressure, solvent and presence of catalyst
poisons. However, the foregoing range will generally
give maximum catalyst yields in terms of weight of
polymer per unit weight of titanium.
Generally in the polymerization process, a
carrier is employed which may be an inert organic
diluent or solvent of excess monomer. In order to
realize the full benefit of the high efficiency catalyst
of the present invention, care must be taken to avoid
oversaturation of the solvent with polymer. I~ such
saturation occurs before 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 about 50 weight
percent based on the total weight of the reaction
mixture.
The polymerization pressures pre~erably
employed are relatively low, e.g., from about 50 to
1000 psig (345-6890 kPa), especially from 100 to 700
psig (689-4820 kPa). However, polymerization within
the scope of the present invention can occur at pres-
sures from atmospheric up to pressures determine~ by
the capabilities of the pol~merization equipment.
During polymerization it is desirable to stir the
polymerization recipe to obtain better temperature
27,723A-F -14-
-15- ~ 17~227
control and to maintain 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
of from about 1 to about 10 weight percent, most advan-
tageously from about 1.2 to about 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 lower the molecular weight of the
resultant polymer. For the purposè of this invention,
it is beneficial to employ hydrogen in concentrations
ranging from about 0.001 to about 1 mole per mole of
monomer. The larger amounts of hydrogen within this
range are found to produce generally lower molecular
weight polymers. It is understood that hydrogen can be
added with a monomer stream to the polymerization
vessel or seperately added to the vessel before, during
~0 or after addition of the monomer to the polymerization
vessel, but during or before the addition of the catalyst.
The monomer or mixture of monomers is contacted
with the catalytis reaction product in any conventional
manner, preferably by bringing the catalytic reaction
product and monomer together with intimate agitation
provided by suitable stirring or other means. Agitation
can be continuea during polymeriæation, or in some
instances, the polymerization mixture can be allowed to
remain unstirred while the polymerization takes place.
In the case of more rapid reactions with more active
catalysts, means can be provided for refluxing monomer(s)
27,723A-F -15-
-16- ~1 7~ 22,~
and solvent, if any of the latter is present, thus
removing the heat of reaction. In any ev~nt, adequate
means should be provided for dissipating the exothermic
heat o~ polymerization. If desired, the monomer(s) 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 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 suitabie cooling medium to maintain the desired
reaction temperature, or by passing the reaction mixture
through an equilibrium overflow reactor or a series of
the same.
1~ The polymer is readily recovered from the
polymerization mixture by driving off unreacted monomer
or solvent if employed. No furthe.r removal of impuri-
ties is required. Thus, a significant advantage of the
present invention is the elimination of the catalyst
residue removal steps. In some instances, however, it
may be desirable to add a small amount of a catalyst
deactivating reagent of the types conventionally employed
for deactivating Ziegler catalysts. The resultant
polymer is found to contain insigni~icant amounts of
catalyst residue and to possess a relatively broad
molecular weight distribution.
The following examples are given to illustrate
the invention. All parts are by molar ratio and percentages
are by wei~ht unless otherwise indicated. The melt
index values I 2 and I1o were determined by ASTM D
1238-70 and the density values were determined by ASTM
D 1248.
27,723A-F -16-
2 2 ~
-17-
The following abbreviations are employed in
the examples.
BEM = n-butyl ethyl magnesium
nBu = normal butyl
DBM = n-butylsec-butyl magnesium
DNHM = di-n-hexyl magnesium
EADC = ethyl aluminum dichloride
Et = ethyl
M = molar
Me = methyl
iPr = isopropyl
nPr = normal propyl
The organometallic compounds and/or complexes are com-
mercially available from Texas Alkyls, Inc., Lithium
Corporation of America and Schering AG Indus~rie-
-Chemikalien.
Examples 1_- 3
A. Preparation of Zr(OnBu)3Cl
To 4.22 gms (0.011 moles) of neat ZrtOnBu)4
was added sufficient Isopar~ E ~an isoparaffinic hydro-
carbon fraction boiling in the range of 116-134C) to
bring the total volume to 100.0 ml. Anhydrous electronic
grade HCl was passed through the solution until a milky
precipitate was formed. Excess HCl was stripped from
the mixture by passing dry N2 through the solution.
B. Preparation of the Catalyst Composltion
The catalysts used were prepared by mixing in
an inert atmosphere the following components in the
order indicated:
27,723A-F -17-
-18- ~17422
96.97 - x ml of Isopar~ E
1.05 ml of 0.95 EADC
x ml of 0.011 M Zr(OnBu)3Cl
0.6 ml of 0.0336 M Ti(OiPr)~
1 . 38 ml of 0.58 M DNHM
100.0 ml
where x can be determined from the following table:
Example x, ml Zr:Ti Ratio
1 0.23 1/8:1
2 0.45 1/4:1
3 0.91 1/2:1
C. Polymerization
A stirred batch reactor containing 2 liters
of Isopar~ E was heated to 150C. The solvent vapor
pressure was 21 psig (145 kPa). To this was added 19
psig (131 kPa) of hydrogen and 120 psig (827 kPa) of
ethylene fo.r a total- reactor pressure of 160 psig (1103
kPa). An amount of the above catalyst (wherein 7.5 ml
= O.0015 mMoles Ti) was injected into the reactor, and
the reactor pressure was maintained constant at 160
psig (1103 kPa) with ethylene. The total reaction time
was 30 minutes. The catalyst efficiency can be found
in Table I with pGlymer physical properti s found in
Table II.
Examples 4-6 and Comparative_~xperiment A
A. Preparation of the Catalyst Composition
The catalysts used were prepared under condi-
tions similar to those for the catalyst preparation in
27,723A-F -18-
2 2 ~
examples 1-3. The following components were mixed in
the following order:
97.57 - x ml of Isopar~ E
1.05 ml of 0.95M EADC
x ml of the Ti(OiPr) 4 =Zr(OnBu) 3 Cl mixture
1.38 ml of 0.58 M DNHM
100.0 ml
where x can be determined from the following table:
Concen- Concen-
tration tration
Example x, ml Ti ZrZr:Ti Ratio
4 0.8 0.025 0.100 4:1
1.540.013 0.100 8:1
6 3.330.096 0.10016:1
A* 0.60.0336 0.0 0:1
*comparative
B. Polymerization
Polymerization conditions were identical to
those for examples 1-3. Catalyst efficiency can be
found in Table I and polymer properties are listed in
Table II.
Com~r.ative Experiment B
A. Preparation of the Cat lyst Composition
The catalyst for this run was prepared under
similar conditions as for examples 1-3. The following
components were mixed in the following order:
27,723A-F -19-
~ ~42~
-20-
97.60 ml of Isopar~ E
0.79 ml of 0.95 EADC
0.14 ml of Zr(OnBu)3Cl
1.46 ml of 0.405 M DBM
100.0 ml
B. Polymerization
Polymerization conditions were identical to
those for examples 1-3. Addition of 0.007S mMoles of
Zr (50 ml of catalyst) produced no observable polymer.
19 Comparative Experiment C
A. PreParation of Catalyst and Polymerization
A comparative catalyst similar to that described
in Comparative Experiment A was prepared and polymerization
was carried out as outlined in examples 1-3.
Examples 7-8
A. Preparation of Zr(OnBu) 3 Cl
To 50.0 mI of Isopar~ E is added 1.17 gm of
ZrCl~. Then, with rapid stirring, 1.37 ml of neat
nBuOH is added. This produces a solution con~aining
0.1 M Zr.
B. Preparation of the Catalyst Composition
The catalysts used in these runs were prepared
under similar conditions as for examples 1-3. The
following components were mixed in the following order:
:
:
27,723A-F -20-
~" -21- 1 1742~7
97.68 - x ml of Isopar~ E
O.75 ml of 1.00 M EADC
0.60 ml of 0.025 M Ti(OiPr)4
x ml of 0.1 M Zr(OnBu)3Cl (as prepared
in A above)
0.97 ml of 0.62 M BEM
100~0 ml
where x can be determined from the following table:
Example x, ml Zr:Ti Ratio
_
7 2.4 16:1
8 1.2 8:1
C.~ ymerization
Polymerization conditions were iden~ical to
those for examples 1-3. Catalyst efficiency can be
found in Table I and polymer properties are listed in
Table II.
Example 9 and Comparative Experiment D
A. Preparation of the Catalyst Com~ ion
The catalysts used were prepared under condi-
tions similar to those for the catalyst preparation inexamples 1-3. The following components were mixed in
the following order:
27,723A-F -21-
2 2 ~
-22-
97.68 - x - y ml of Isopar~ E
0.75 ml of 1.00 EADC
0.6 ml of 0.025 M Ti(OiPr)4
x ml of 0.1 M ZrCl4 (slurry in Isopar~ E)
y ml of 0.3 M n-butanol
0.97 ml of 0.62 M BEM
100.0 ml
where x and y can be determined from the following
table:
Zr:Ti nBuOH:Zr
Example x, ml y, ml Ratio Ratio
~ 1.2 1.2 8:1 3:1
D 1.2 0 8:1
B. Polymerization
Polymerization conditions were identical to
those for examples 1-3. Catalyst efficiencies can be
found in Table I and polymer properties are listed in
Table II.
.
As can be seen in Table II in Examples 1
through 6 and Comparati~e Experiment A, increasing the
level of the zirconium compound in the catalyst while
holding all other factors constant leads to a lowering
of the melt index from 16.4 gm/10 min. for a catalyst
with no zirconium to 4.3 gm/10 min. for a catalyst
containing 16 zirconiums. This is unexpected and
provides a method of controlling the polymer's molecular
weight (melt index~ without adjusting the amount of the
normal chain terminator (H2).
27,723A-F -22
-23- 3.17~22~
Examples 7 and 8 again show this unexpected
property of melt index lowering when compared to
Comparative Experiment C. Example 9 and Comparative
Experiment D also show melt index lowering because of
the zirconium compound present, but Example 9 has a
narrower molecular weight distribution, as evidenced by
the I1o/I2 ratio, because of the presence of n-butyl
alcohol in the mixture.
27,723A-F -23-
N --24-- 3L 1 7 ~12 2 7
" + n
CD ~ ~ ~ ~ n In O
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,,
~ ~1 ~1 ~1 ~ ~ O ~ O ~ O ~ O O
U
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d' ~ d1
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N ~I r l a w N W
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~R ~ ~ ~ ~ ~ ~ ~ I
~1 h h ~ h~I h h
P~
rl rl ~ rlrl rl rl O r-l
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rl rl h r-l~rl rl rl 11) ~3) ,C
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27, 723A-F -24-
. .,
`` -25- ~ 17~2~
TABLE II
Example &
Comparative DENSITY
Experiment #I2 ~lQ ~lQ~Z g/cc
1 16.39 124.40 7.59 0.9678
2 17.31 127.22 7.35 0.9678
3 15.09 115.04 7.62 0.9671
4 8.93 68.51 7.67 O.g658
5.38 44.71 8.31 0.9651
6 4.30 36.08 8.39 0.9631
A 16.37 114.7S 7.01 0.9663
B*
C 13.62 97.11 7.13 0.9673
7 1.84 l9.g6 10.85 0.9624
8 6.02 47.36 7.87 0.9649
9 2.48 22.16 8.94 0.9636
D 2.10 20.61 9.81 0.9619
* no polymer produced
27,723A-F -25-
