CA1154421A - Ultra high efficiency catalyst for polymerizing olefins - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Compositions resulting from the mixing of a transition metal compound such as a tetraalkoxy titanium compound and a zinc compound such as a dialkyl zinc compound are useful in preparing catalysts for the polymerization of .alpha.-olefins at high temperatures with ultra-high efficiencies.

Description

ULTRA HIGH EFFICIENCY CATALYST
FOR POLYMERIZING OLEFINS

This invention relates to new catalyst com-positions useful for the polymerization of ~-olefins and to a polymerization process employing such catalyst compositions.

It is well known that olefins such as ethylene, propylene and 1-butene can be polymerized in the presence of metallic catalysts, particularly the reaction products of organometallic compowlds and transition metal compounds, to form substantially un~ranched polymers of relatively high molecular weight.
Typically, such polymerizations are carried out at rela-tively low temperatures and pressures with an inert organic liquid diluent or carrier. Following polymeri-zation, it is common to remove catalyst residues from the polymer by repeatedly treating the polymer with alcohol or other deactivating agent such as aqueous base. Such catalyst deactivation and/or removal pro-cedures are expensive both in time and materialconsumed as well as the equipment required to carry out such treatment.

27,~22A-F -1-.~, ~ t~

Most known catalyst systems are more effi-cient in preparing polyolefins in a slurry rather than in solution at a temperature high enough to solubilize the polymer in the carrier. The lower efEici~ncies of such catalysts in solution polymerization is believed to be caused by rapid depletion or deactivation at the significantly higher temperatures normally employed in solution processes. Also, processes involving the copolymerization of ethylene with higher ~-olefins exhibit catalyst efficiencies significantly lower than in ethylene homopolymerization.

Recently, catalysts having higher efficien-cies have been disclosed, e.g., U.S. Patents 3,392,159, 3,737,393, and 4,115,319; West German Patent Application

2,231,982 and British Patents 1,305,610, 1,358,437, and 1,492,379. While the increased efficiencies achieved by using these recent catalysts are significant, even higher efficiencies are desirable, particularly in copolymerization processes. Also, higher reaction temperatures reduce the energy requirements, particu-larly in removing the solvent.

The present invention in one aspect is a transition metal compound suitable for use in the pre-paration of olefin polymerization catalysts which is the reaction product or complex formed by mixing at a temperature and time sufficient to provide a color change (a) a transition metal compound having at least one hydrocarbyloxy group attached to said transition metal and (b) a zinc compound;

27,822A-F -2-., wherein the atomic ratio of Zn to transition metal (Tm) is at least 0.03:1, preferably from about 0.12:1 to 5:1 and most preferably from about 0.25:1 to 2:1. Higher Zn:Tm ratios can be employed, however, no particul~r advantage is observed and the higher levels increase the cost of catalysts produced therefrom.

Another aspect of the present invention are catalysts for polymerizing ~-olefins which comprise the reaction product of ~a) the above transition metal reaction product or complex;
(b) a magnesium halide resulting from the reaction of (1) an organomagnesium component and (2) a halide source; and (c) an organoaluminum compound, if reguired.

The components are employed in quantities which provide the composition with atomic ratios of the elements as follows:
Mg:Tm is from 1:1 to 2000:1, preferably from 2:1 to about 200:1 and most preferably from 5:1 to 75:1.
Al:Tm is from 0.1:1 to 2000:1, preferably from 0.5:1 to 200:1 and most preferably from 1:1 to 75:1.
Excess X:Al is fro~ 0.0005:1 to 10:1, preferably from 0.002:1 to 2:1 and most preferably from 0.01:1 to 1.4:1.
Excess X is the amount of halide above that amount theoretically required to convert the organomagnesium component to magnesium dihalide.

27,822A-F -3-~ ..

The present invention is most advantageously practiced where an ~-olefin is polymerized, generally in the presence of hydrogen as a molecular weight con-trol aqent, in a polymerization zone containin~ an inext diluent and the catalytic reaction product.
Especially advantageous is the copolymerization of ethylene and higher ~-olefins using the ultra high efficiency catalysts. The polymerization is most beneficially carried out under inert atmosphere and relatively low temperature and pressure, ~lthough very high pressures are optionally employed.

Olefins which are suitably homopolymerized or copolymerized in the practice of this invention are aliphatic ~-monoolefins or a-diolefins having from 2 to 18 carbon atoms. Illustrative of such ~-olefins are ethylene, propylene, butene-l, pen-tene-l, 3-methylbutene-1, 4-methylpentene-1, hexene-l, octene-1, dodecene-1, octadecene-l, 1,7-octadiene, and mixtures thereof. 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 other ethylenically unsaturated monomers such as styrene, ~-ethylstyrene and similar ethyleni-cally unsaturated monomers which do not destroy conven-tional Ziegler catalysts. Most benefits are realizedin the polymerization of aliphatic ~-monoolefins, par-ticularly ethylene and mixtures of ethylene and up to 50, especially from 0.1 to 40 weight percent, of propylene, butene-l, hexene-l, octene-l, 4-methyl-pentene-l, 1,7-octadiene or similar higher ~-olefin or diolefin based on total monomer.

27,822A-F -4-ll'j'l~;'l Suitable æinc compounds advantageously employed are those represented by the formulae R2Zn or RZnX wherein each R is independently a hydrocarbyl group having from 1 to about 20, preferably from 1 to about 10, carbon atoms and X is a halogen, preferably chlorine or bromine. Particularly suitable zinc com-pounds include, for example, diethyl zinc, diphenyl zinc, ethyl zinc chloride, mixtures thereof and the like.

Suitable transition metal compounds which can be employed in the present invention include those represented by the formulae Tm(OR)yXx y and Tm(OR)x 2 wherein Tm is a transition metal selected from groups IVB, VB or VIB; each R is independently a hydrocarbyl group, preferably alkyl or aryl, having from 1 to 20, preferably from 1 to 10, carbon atoms; each X is inde-; pendently a halogen, preferably chlorine or bromine;
x has a value e~ual to the valence of Tm and y has a value from 1 to the valence of Tm.

Particularly suitable transition metal compounds include for example tetraethoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium, di-n-butoxy titanium dichloride, tetraphenoxy tita-nium, tetra-n-propoxy titanium, tetra-(2-ethylhexoxy) titanium, tri-n-butyoxy vanadium oxide, oxyvanadium trichloride, tri-isopropoxy vanadium oxide, zirconium tetra-n-butoxide, zirconium tetra-n-propoxide, zir-:~ conium tetra-isopropoxide, and mixtures thereof.

: Suitable organomagnesium components which can be employed in the present invention include those 27,822A-F -5-. .

ll''t~1 represented by the formula MgR"2 xMR"y wherein each R"
is independently hydrocarbyl or hydrocarbyloxy, M is aluminum, zinc or mixtures thereof and x is about ~ero to about 10, preferably 0.001 to 5, most preferably from 0.15 to 2.5 and y denotes the number of hydro-carbyl and/or hydrocarbyloxy groups which corresponds to the valence of M. 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, hydrocarbyloxy is alkoxy, cycloalkyloxy, aryloxy, aralkyloxy, alkenyloxy and similar oxyhydro-carbon radicals having 1 to 20 carbon atoms, withalkyloxy having 1 to 10 carbon atoms is preferred.
Hydrocarbyl is preferred over hydrocarbyloxy.

Preferably the organomagnesium compound is a hydrocarbon soluble dihydrocarbylmagnesium such as the magnesium dialkyls and the magnesium diaryls.
Exemplary suitable magnesium dialkyls include parti-cularly 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 the alkyl has from 1 to 20 carbon atoms. Exemplary suitable magnesium diary~s include diphenylmagnesium, dibenzylmagnesium, and ditolylmagnesium. Suitable organomagnesium compounds include alkyl and aryl mag-nesium alkoxides and aryloxides and aryl and alkylmagnesium halides with the halogen-free organomag-nesium compounds being more desirable.

27,822A-F -6-1~ 4~1 Among the halide sources which can be employed are the active non-metallic hdlides and metallic halides.

Suitable non-metallic halides are repre~en-ted by the formula R'X wherein R' is hydrogen or anactive monovalent organic radical and X is a halogen.
Particularly suitable non-metallic halides include, for example, 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 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 above are also suitably employed. Examples of preferred active non-metallic halides include hydrc,gen chloride, hydrogen bromide, t-butyl chloride, t-amyl bromide, allyl chloride, benzyl chloride, crotyl chloride, methylvinyl carbinyl chloride, ~-phenylethyl bromide, diphenyl methyl chloride and the like. Most preferred are hydrogen chloride, t-butyl chloride, allyl chloride and benzyl chloride.

Suitable metallic halides which can be employed herein include those represented by the formula MRy aXa wherein M is a metal of Groups IIB, IIIA or IVA, of Mendeleev's Periodic Table of Elements, R is a monovalent organic radical, X is a halogen, y 27,822A-F -7-has a value corresponding to the valence of M and a has a value from 1 to y. Preferred metallic halides are aluminum halides of the formula AlR3 aXa wherein each R is indepenAently hydrocarbyl as defined above such as alkyl, X is a halogen and a is a number from 1 to 3. Most preferred are alkylaluminum hali~es such as ethylaluminum sesquichloride, diethylalumi-num chloride, ethylaluminum dichloride, and diethyl-aluminum bromide, with ethylaluminum dichloride being especially preferred. Alternatively, a metal halide such as aluminum trichloride or a combination of alumi-num trichloride with an alkyl aluminum halide or a trialkyl aluminum compound may be suitably employed.

It is understood that the organic moieties of 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.

In preparing the reaction product or complex of the present invention from the zinc and transition metal compounds, the two components are simply mixed together in a suitable solvent at any suitable tempera-ture, usually from about -50C to 100C, preferably from about 0C to 30C, for a time sufficient to cause a color change in the reaction mixture. The exact color change varies depending upon the particular components employed.

27,822A-F -8-The reaction time is also affected by the temperature and concentration of the reactants, e.g., lower temperatures and concentrations require longer times. The solvents which can be employed include those suitable for preparing the catalysts of this invention. Hydrocarbon solvents are most suitable.

The magnesium halide can be preformed from the organomagnesium compound and the halide source or it can be prepared in situ in which instance the catalyst is prepared by mixing in a suitable solvent (1) the organomagnesium component; (2) the halide source and (3) the reaction product or complex formed by mixing (a) said transition metal compound and (b) said zinc compound.

The foregoing catalyst components are com-bined in proportions sufficient to provide atomic ratios as previously mentioned.

In cases wherein neither the organomagnesium component nor the halide source contains aluminum or contains an insufficient quantity of 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 0.1:1 to 2000:1, preferably from 1:1 to 2G0:1.
However, when polymerization temperatures above 180C
are employed, the aluminum compound is used in propor-tions 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 27,822A-F -9-`

~ 4~1 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 in the polymeri-zation zone. Further, other components present in the zone 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, it is understood that in the catalyst the aluminum com-pound should be in the form of trialkyl aluminum or alkyl aluminum halide provided that the alkyl aluminum halide be substantially free of alkyl aluminum dihalide.
In the above mentioned aluminum compounds, the alkyl groups independently have from l to about 20, prefer-ably from l to about 10 carbon atoms.

When additional quantities of aluminum com-pound are employed, it can be added to the catalyst during preparation or the aluminum deficient catalyst can be mixed with the appropriate aluminum compound prior to entry into the polymerization reactor or, alternatively, the aluminum deficient catalyst and the aluminum compound can be added to the polymeri-zation reactor as separate streams or additions.

The foregoing catalytic reaction is prefer-ably carried out in the presence of an inert diluent using the concentrations of catalyst components such that the catalytic slurry is from about 0.005 to 1.0 molar (moles/liter) with respect to magnesium. Suit-able inert organic diluents include liquified ethane, propane, isobutane, n-butane, n-hexane, the various 27,822A-F -10-.. . . .
', .' ~ . , .
~ ' .

isomeric hexanes, isooctalle, paraffinic mixtures of alkanes having from 8 to 12 carbon atoms, cyclohexane, methylcyclopentane, dimethylcyclohexane, dodec~ne, and industrial solvents composed of saturated or aro-matic 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 -50 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 re`action product is advantage-ously carried out under an inert atmosphere such as nitrogen, argon or other inert gas at temperatues in the range from about -100 to 200C, preferably from about 0 to 100C. The period of mixing is not critical as a sufficient catalyst composition most often is formed within about one minute or less. In the preparation of the catalytic reaction product, it is not necessary to separate hydrocarbon soluble com-ponents from hydrocarbon insoluble components of the reaction product.

To maximize catalyst efficiency, the cata-lyst is prepared by mixing the components of the catalyst in an inert liquid diluent in the following especially preferred order: organomagnesium compound, halide source, the aluminum compound if required, and ~ the reaction product or complex transition metal compound and zinc compound.

27,822A-F -11-11' 4~

In the polymerization process employing the catalytic reaction product, polymerization is effected by adding a catalytic amount of the catalyst to a polymerization zone containing ~-olefin monomer, or vice versa and maintaining the mixture at tempera-tures in the range from about 0 to 300C, preferably at solution polymerization temperatures of about 130 to 250C, for a residence time of a few seconds to several days, preferably 15 seconds to 2 hours. A
catalytic amount of the catalyst is generally about 0.0001 to 0.1 millimole titanium per liter of diluent.
However, that the most advantageous catalyst concen-tration will depend upon polymerization conditions such as temperature, pressure, solvent and presence of catalyst poisons and the foregoing range is given to obtain maximum catalyst yields in weight of polymer per unit weight of titanium.

Generally, a carrier which may be an inert organic diluent or solvent or excess monomer is employed. 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. If such saturation occurs before the i 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 preferably employed are relatively low, e.g., from about 50 to 1000 psig (0.45 to 7.0 MPa), especially from about 27,822A-F -12-.
:
~ : ' 100 to 700 psig (0.79 to ~.93 MPa). However, polym-erization within the scope of the present invention can occur at pressures from atmospheric up to pres-sures determined by the capabilities of the polym-erization equipment. During polymerization i-t is desirable -to stir the polymerization recipe to obtain better temperature control and to maintain uniform polymerization mixtures througout 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 advantageously 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 control the molecular weight of the resultant polymer. For the purpose 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. Hydrogen can be added with a monomer stream to the polymeriæation 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.

27,822A-F -13-The monomer or mix-ture of monomers is contacted with the catalytic 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 continued durin~ polym-erization, or in some instances, the polymerization can be allowed to remain unstirred while the polym-erization 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, in order to remove the heat of reaction. In any event, adequate means should be provided for dissipating the exothermic heat of polym-erization. If desired, the monomer can be brought inthe vapor phase into contact with the catalytic reac-tion 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 suitable cooling media to maintain the desired reaction temperature, or by passing the reaction mix-ture through an equilibrium overflow reactor or a series of the same.

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 signi-ficant advantage of the present invention is theelimination of the catalyst residue removal steps.
In some instances, however, it may be desirable to 27,822A F -14-add a small amount of a cat~lyst deactivating reagent of the types conventionally employed for deactivating Ziegler catalysts. The resultant polymer is found to contain insignificant amounts of catalyst residue an~
to possess a relatively narrow molecular weigh-t dis-tribution.

The following examples are given to illus-trate the invention. ~11 percentages are by weight and all parts are by molar or atomic ratio unless otherwise indicated.

In the following examples, the melt index values I2 and I1o were determined by ASTM D 1238-70 and the density values were determined by ASTM D 1248.

A. Preparation of the diethyl zinc-titanium com~lexes -A stock solution (0.025M) of titanium tetraethoxide (Ti(oEt)4), titanium tetra-n-propoxide (Ti(OnPr)4), titanium tetra-isopropoxide (Ti(OiPr)4), titanium tetra-n-butoxide (Ti(OnBu)4), and titanium tetra -(2-ethylhexoxide) (Ti(OEH)4) was prepared by mixing the amount of neat solution indicated in Table I with sufficient Isopar~ E (an isoparaffinic hydrocarbon fraction having a boiling range of 116 to 134C) to bring the total volume to 100.0 ml. After the solution was well mixed, 10.0 ml of the solution was transferred to a small vial where it was mixed with 10.0 ml of 0.025 M diethyl zinc (DEZ) prepared by diluting 2.84 ml of 0.88 M DEZ to 100 ml using Isopar~ E. The final titanium and DEZ concentrations 27,822A-F -15-were 0.0125 M. These solutions developed characteris-tic colors as indicated in Table II and were stored in amber bottles -to prevent photodecomposition of the complex.

TABLE I

Amount of Titanium Species Needed for a 0.025 M Stock Solution Titanium Component ml Neat Solution Needed Ti(oEt)4 0.52 Ti(OnPr)4 0.74 Ti(OiPr)4 0.74 Ti(OnBU)4 0.86 Ti(oEH)4 1.52 27,822A-F -16-~.

- ~
o --u u c~ u ~-~
u~ o ,~
--~
E~
o~
u~ o ~v ~

H~ H ~ _ HZ r~
O ~ O O
W~ E~ ~ _ U U U o ~ ~ m ~u~ E~ E~
E~
~Z
E-l H a~
X
.
~U~ ~ ~ X
1~ O ~ a) :~ a) h a~ h ~ = = =
H _ .~1 S_l r~
'E~

~ .
_ ~ O
o ~
_ '~
E~ ~ ~v ~m ' .,, ~-~1 o Ul o O ~ ~ ~
h ~ ,1 ~o 27, 822A-F -17-B. Preparation of the CatalYst Composition The catalyst composition was prepared by mixing with stirring under a nitro~en atmosphere the following components added in the following order:
97.07 ml of Isopar~ E
0.93 ml of 0.64 M di-n-butyl ma~nesium 0.80 ml of 0.94 M ethyl aluminum dichloride 1.20 ml of 0.0125 M diethyl zinc-titanium complex 100.0 ml The temperature of the mixture was maintained at ambient temperature (about 22C). Depending on the complex used, the catalyst was initially a bright yellow color. The catalyst then paled to a straw color over a period of lO minutes, after whicb time there was no significant change in catalyst color.

; C. Polymerization A stirred batch reactor containing 2 liters of Isopar~ E was heated to 150C. The solvent vapor pressure was 21 psig (0.25 MPa). To this was added 6 psig (0.041 MPa) of hydrogen and 173 psig (1.19 MPa) of ethylene for a total reactor pressure of 200 psig (1.48 MPa). Rn amount of the above catalyst was injected into the reactor (10 ml = 0.0015 mmole Ti), and the reactor pressure was maintained constant at 200 psig (1.48 MPa) with ethylene. The total reac-tion time was 20 minutes. The titanium species used and catalyst efficiencies are given in Table III.

27,822A-F -18-..~

COMPARATIVE EXPERIMENTS A-E
A. Preparation of the Catalyst Composition Using the titanium stock solutions prepared above, the catalyst composition was prepared by mixing with stirring under a nitrogen atmosphere, the following components added in the following order:
97.67 ml of Isopar~ E
0.93 ml of 0.64 M di-n-butyl magnesium 0.80 ml of 0.94 M ethyl aluminum dichloride 0.60 ml of 0.025 M titanium stock solution ~ 100.0 ml The catalyst was an initial straw color which darkened to a brownish color ovex a period of an hour.
After this time, no further changes were detected.

lS B. Polymerization Each of the catalysts were employed to polymerize ethylene using the conditions for Exam-ples 1-5. The results are also shown in Table III.

COMPARATIVE EXPERIMENT F
A. Preparation of the Catalyst Composition A catalyst composition was prepared where the diethyl zinc was not premixed with the titanium source, but rather was added directly to the catalyst.
The catalyst composition was prepared by mixing the following components added in the following order:
97.07 ml of Isopar~ E
0.93 ml of 0.64 M di-n-butyl magnesium 0.80 ml of 0.94 M ethyl aluminum dichloride 0.60 ml of 0.025 M Ti(OiPr) 0.60 ml of 0.02S M diethyl 4zinc 100.0 ml 27,822A-F -19-a~t2l The catalyst was the same color as those prepared for comparative experiments A-E.

B. Polymerization The catalyst was employed to polymerize ethylene using the conditions for Examples 1-5.
The result is also shown in Table III.

; TABLE III

Polymerization Results Example &
10 Comp. Exp.Titanium Catalyst Efficiency Exotherm Number Species Million # PE/# Ti C
12 DEZ-Ti(oEt)4 2.76 23 22 DEZ-Ti(OnPr)4 2.80 25 2 DEZ-Ti(OiPr)4 2.85 22 4 DEZ-Ti(OnBu)4 2.83 25 52 DEZ-Ti(OEH)4 2.89 22 A Ti(OEt)4 2.35 18 B Ti(OnPr)4 2.64 21 C Ti(OiPr)4 2.30 13 D Ti(OnBu)4 2.73 20 E Ti(oEH)4 2.64 20 F DEZ-Ti(OiPr)4 2.57 13 1 Exotherm is the initial rise in reactor temperature from 150C when the catalyst is added to the reactor.
2 DEZ and titanium compound premixed to form a complex or reactive product.

3 DEZ and titanium compound added separately.

27,822A-F -20-, .

.

A. Preparation of Diethyl Zinc-Ti(OiPr)~
Complexes To 1.0 ml of neat Ti(OiPr)4 was adde~l varying amounts of 0.88 M diethyl zinc as indicated in Table IV. These mixtures were then diluted -to 100.0 ml with Isopar~ E, giving a titanium concen-tration of 0.0336 M. Again, these solutions are stored in amber bottles to prevent photodecomposi-tion.

B. Preparation of the Catalyst ComPositions Using the diethyl zinc-titanium solutions prepared above, the catalyst composition was prepared by adding, with stirring under a nitrogen atmosphere the following components added in the following order:
97.95 ml of Isopar~ E
0.80 ml of 0.745 M di-n-hexyl magnesium 0.80 ml of 0.94 M ethyl aluminum dichloride 0.45 ml of 0.0336 M diethyl zinc-titanium mixture 100.0 ml 27,822A-F -21-a r l P~ ~
h .C
1:~ ~ P~
O r~ X X ~ ~ ~ r~
r l O ~ rl O ~ r I r-t ~ a r l ~ l O
~ r I O p~ Ll O ~1]
r l rl $~
O ~ t~ P~
O r O ~ X X ~ .
rl H ¦-1 )-I ~ t51 a) IU ~
rl rl r-l r-l r-l 1~ 0 C) V
~1 o U~
r-l PiO - rl rl E-l rl r-l r-lrl r~ ~ rl O ~ ... .. .~
D ~ ~ O
~> P~ ~ \ \ \ ~ ~
,_, d ~ r-l r~ \ \
_ rl r~
W
P~
mr~
~tO
rl ~
E-l _ O O O O O O O
r-l - rl O O O O O O O
F O
_ r-l r-l ~ ~ r~ ~I r-l rl o rl ~D00 d' OD
r I t~) ~1 o o o o o x a w r l 51 ~s) 1~oo ~ o r~
~ ~ ~ r i r I
3~3 27, 822A-F -22-11~,4'~

C. P~l~merizations Each of the catalysts were employed to polymerize ethylene using the conditions for Exam-ples 1-5. The results are shown in Table V.

COMPARATIVE EXPERIMENT G
A. Preparation of the Catalyst Composition A catalyst was prepared following the proce-dure given in Examples 6-11 above except that Ti(OiPr)4 alone was used in place of the diethyl zinc-Ti(OiPr~4 complex. The catalyst color was similar to that of other catalysts--a straw brown in color.

B. Polymerization The comparative catalyst was employed to polymerize ethylene using the conditions for Examples 1-5. The result is shown in Table V.

TABLE V

Polymerization Results Example ~ - 1 Comp. Exp. Ratio Catalyst Efficiency Exotherm 20 NumberZn:Ti Million # PE/# TiC
61:1 3.28 14 71/2:1 3.34 16 81/4:1 3.32 13 91/8:1 2.93 12 101/16:1 3.02 13 111/32:1 2.62 10 G 0:1 2.71 9 1 Exotherm is the initial rise in reactor temperature from 150C when the catalyst is added to the reactor.

27,822A-F -23-' '

Claims (10)

1. In a catalyst composition comprising (A) a transition metal (Tm) compound and a zinc compound, (B) a magnesium halide, and (C) an aluminum compound, said composition having an atomic ratio of the elements Mg:Tm of 1:1 to 2000:1; Zn:Tm at least 0.03:1; Al:Tm of 0.1:1 to 2000:1 and an excess X:Al of 0.0005:1 to 10:1; the improvement which compises forming a reaction product or complex of the transition metal compound and the zinc compound prior to preparation of the cata-lyst therefrom by admixture of:
(a) at least one transition metal compound represented by the formulae Tm(OR)yxx-y or Tm(OR)x-2O wherein Tm is a transition metal selected from groups IVB, VB, VIB; each R is independently a hydrocarbyl group, having from 1 to about 20 carbon atoms; each X is indepen-dently a halogen; x has a value equal to the valence of Tm and y has a value from 1 to the valence of Tm; and (b) at least one zinc compound represented by the formulae R2Zn and RZnX wherein each R is independently a hydrocarbyl group having from 1 to 20 carbon atoms and X is a halogen; and wherein these components are mixed in proportions such that the atomic ratio of Zn:Tm is at least about 0.03:1.

27,822A-F -24-

2. The catalyst composition of of Claim 1 wherein in component (a) Tm is titanium, each R is independently a hydrocarbyl group having from 1 to 10 carbon atoms and X is chlorine or bromine; com-ponent (b) has the formula ZnR2 wherein R is a hydro-carbyl group having from 1 to 10 carbon atoms; and the Zn:Ti atomic ratio is from 0.12:1 to 5:1.

3. The catalyst composition of Claims 1 or 2 wherein component (a) is titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-isopro-poxide, titanium tetra-n-butoxide or titanium tetra--(2-ethylhexoxide), component (b) is dimethyl zinc, diethyl zinc, or diphenyl zinc, and the Zn:Ti ratio is 0.25:1 to 2:1.

4. The catalytic reaction product of (A) the reaction product or complex formed from the admixture of (1) at least one transition metal compound represented by the formulae Tm(OR)yxx-y or Tm(OR)x 2° wherein Tm is a transition metal selected from groups IVB, VB or VIB; each R is independently a hydro-carbyl group, having from 1 to about 20 carbon atoms; each X is independently a halogen; x has a value equal to the valence of Tm and y has a value from 1 to the valence of Tm; and (2) at least one zinc compound represented by the formulae R2Zn and RZnX wherein each R is independently a hydrocarbyl group having from 1 to 20 carbon atoms and X is a halogen; and 27,822A-F -25-(B) a magnesium halide resulting from the reaction of (1) an organomagnesium compound represented by the formula MgR"2?xMR"y wherein M is aluminum or zinc, each R" is indepen-dently a hydrocarbyl or hydrocarbyloxy group having from 1 to 20 carbon atoms, x has a value from zero to 10 and y has a value corresponding to the valence of M; with (2) a halide source selected from (a) an active non-metallic halide, said non-metallic halide corresponding to the formula R'X wherein R' is hydrogen or a hydrocarbyl group such that the hydrocarbyl halide is at least as active as sec-butyl chloride and does not poison the catalyst, and X is halogen or (b) a metallic halide corresponding to the formula MRy-aXa wherein M is a metal of Group IIB, IIIA or IVA of Mendeleev's Periodic Table of Elements, R is a monovalent hydrocarbyl radical, X is halogen, y is a number correspon-ding to the valence of M and a is a number of 1 to y; and (C) when the organomagnesium component and/or the halide source provides insufficient quantities of aluminum, an aluminum compound represented by the formula A1Ry'Xy" wherein R and X are as defined above and y' and v" each have a value of from 0 to 3 with the sum of y' and y" being 3; and wherein the com-ponents are employed in quantities which provide an atomic ratio of the elements Mg:Tm of 1:1 to 2000:1;

27,822A-F -26-Zn:Tm at least about 0.03:1; Al:Tm of 0.1:1 to 2000:1 and an excess X:Al of 0.0005:1 to 10:1.

5. The catalytic reaction product of Claim 4 wherein in Component A-1, R is a saturated aliphatic hydrocarbyl group having from 1 to 10 carbon atomsi in component B-1, x has a value of 0.15 to 2.5, and the components are employed in quantities which pro-vide atomic ratios of Mg:Ti of 5:1 to 75:1, Zn:Ti of 1:1 to 75:1, and excess X:Al of 0.01:1 to 1.4:1.

6. The catalytic reaction product of Claim 4 wherein component A-1 is titanium tetraethoxide, tita-nium tetra-n-propoxide, titanium tetra-isopropoxide, titanium tetra-n-butoxide, or titanium tetra-(2-ethyl-hexoxide); component A-2 is dimethyl zinc, diethyl zinc or diphenyl zinc; component B-1 is a dialkyl magnesium compound wherein the alkyl groups indepen-dently have from 1 to 10 carbon atoms; and component B-2 is anhydrous hydrogen chloride, ethyl aluminum dichloride, or tin tetrachloride.

7. The catalytic reaction product of Claims 4 to 6 wherein the components are added in the order B-1, B-2, C, if employed, and A.

8. The catalytic reaction product of Claims 4 to 6 wherein the components are added in the order B-1, B-2, A and C, if employed, and provided that the halide source, B-2, is not a tin compound.
27,822A-F -27-

9. A process for polymerizing one or more .alpha.-olefins which comprises conducting the polymerization under Ziegler polymerization conditions in the presence of a catalyst of Claim 1.

10. The process of Claim 9 wherein ethylene or a mixture of ethylene with from 0.1 to 40 weight percent of a C3-C18 .alpha.-olefin is polymerized.

27,822A-F -28-