CA1125732A - Catalyst system for olefinic polymerization - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A new improved catalyst system for alpha-olefin type polymerizations includes a metal di- or tri-halide compound of Al, Ga, or In and a diorganomagnesium compound in combination with a Group IVB-VIII transition metal compound. The improved catalyst system provides increased polymerization activity and polymers having a high degree of isotactic stereoregularity.

Description

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2 The present invention relates to unique and novel

3 catalyst systems for the conventional alpha-olefin type

4 polymeriæation at significantly improved polymerization activi~y, wherein the resultant polymers have a high degree 6 of isotactic stereoregularity 7 An object of my present invention is to provide 8 improved catalyst systems having a ma~or increase in poly-9 merization activity while being able to control over a wide range the polymer crystallinity, e.g. isotacticity, wherein 11 the catalyst system includes a transition metal compound, a 12 diorg~nomagnesium compound, and a di- or tri-halide compound 13 of Al, Ga, or In.
14 It is well known in the art to use an alkyl metal compound of Groups I-III in combination with a transition 16 metal compound of Groups IVB-VIII as a catalyst sy~tem for olefinic polymerization. While nearly all of the alkyl metal 8 compounds are effective for the polymerization of ethylene, 19 only a few are effect-ive for the preparation of isotactic polymers of propylene and higher alpha olefins and only 21 Et2AlCl and AlEt3 have any important commercial utility.
22 A major cost involved in the polymerization of the 23 alpha olefins is the cost of the catalyst ~omponents. There-24 fore, the cost of the manufacture of the polymer can be effectively reduced by the use of catalyst systems having 26 a higher polymerization ac~ivity. A further concern is the 27 ability to produce polymers having a minimum amount of cata-28 lyst residues thereby eliminating a c~stly deashin~ operation.
29 A still further concern is the ability to produce polymers ~ having a high degree of isctactic stereoregularity thereby 31 enabling the manufacturer to eliminate the costly operation 32 involving the removal and separation of atactic polymer from ~ 1~ 57 ~ ~

l the isotactic polymer. The improved catalyst system of the 2 present instant invention provides a means to the manufac-3 turer of obtaining these desirable realizations.
4 The improved catalyst systems of thé present in-vention which are employed in alpha-olefin polymerizations 6 include a Group IVB-VIII transition metal compound, a metal 7 di- or tri-halide compound of Al, Ga, or In and a diargano-8 magnesium compound 9 The transition metal catalyst compound is a Group lo IVB-VIII transition metal halide, wherein the halide group ll is chloride or bromide and the transition metal halide is 12 in the form of solid crystalline compounds, solid solutions 13 or compositions with other metal salts or supported on the 14 surface of a wide range of solid supports~ For highest stereospecificity it is desirable to have the transition 16 metal halide, or its support composition~ in the layer 7 lattice structure with very small crystallites, high surface 8 area, or sufficient defects or foreign components to facil-19 itate ~igh dispersion during polymerization. The transition metal halide may also contain various additives such-as 2l Lewis bases, pi bases, polymers, or organic or inorganic 22 modifiers. Vanadium and titanium halides such as VC13, VBr3, 23 TiC13, TiCl49 TiBr3 or TiBr4 are preferred9 most preferably 24 TiC13 or TiCl4 and mixtures thereof, The most preferred TiC13 compounds are those which contain TiC14 edge sites on 2~ the layer lattice support such as alpha, deltag ~r gamma 27 TiC13 or variou~ structures and modifications of TiC13 on 28 MgC12. The most preferred TiC14 compounds are those sup ported on chloride layer lattice compounds such as MgC12.
Minor amounts of other ~nions may be also present such as 31 other halides, pseudohalides) alkoxides, hydroxides, oxides, 32 or carboxylates. Mixed salts or double salts such as K2TiC16

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1 or MgTiC16 can be employed ~lone or in combination with 2 elec~ron donor compounds. Other supports besides MgC12 3 which are useful are hydroxychlorides, oxides, or other 4 inorganic or organic supports. The most preferred crystal structure of TiC13 is delta or pseudo delta, the latter

6 being a mixture of alpha and gamma crystallites. The TiC13-

7 type ca~alysts may be prepared from TiCl~ by any one of the

8 reduction and crystallization procedures known in the art

9 (H2, metal, metal hydrides, metal alkyls, etc.). "Low aluminum" containing TiC13 refers to TiC13 catalysts which 11 have low Al content because of the method of formation or 12 because a major portion of the aluminum wa~ removed in sub-13 sequent reactions~
4 For the alkyl metal cocatalysts of this invention, the most preferred transition metal compounds contain TiC14 16 supported on MgC12 and, optionally, one or more Lewis bases.
17 The metal di- or tri-halide compounds are selected 18 from the group consisting essentially of a metal halide com-19 pound selected from the group consisting of R'IWX2 or R"WXY
and mixtures thereof, wherein W is selected from the group 21 consisting of Al, Ga, and In, R'l is selected from the group 22 consisting of Cl to C20 alkyl3 branched alkyl, cycloalkyl, 23 naphthenic and aryl or aralkyl groups which may also contain 24 a Lewis base functionality; X is a halide selected from the group consisting of chloride and bromide and Y is selected 26 from the group consistlng of chloride, bromide, or a mono-27 valent anion which cannot initiate polymerization of ole-28 finic nomers, wherein the anion is selected from the group ~ consisting of alkoxide, phenoxide, thioalkoxide, carboxylate, etc. Typical but non-limiting examples are ethyl aluminum 31 dichloride~ aluminum trichloride, ethyl aluminum dibromide, 32 ethyl chloroaluminum bromide, octyl aluminum dichloride, ~ 1 ~ 5'7~ ~

1 ethyl indium dichloride, butyl aluminum dichloride, benzyl 2 aluminum dichloride9 ethyl chloroaluminum butoxide, and 3 mixtures thereof. Mixtures of metal halide compounds can 4 be readily employed The C2-C4 alkyl aluminum dihalides are most pre-6 ferred ~or high stereospecificity and the monoalkylaluminum 7 dichlorides are most preferred.
8 The diorganomagnesium compound has the general 9 formwla R R'Mg wherein R and R' can be the same or different and R and R' are selected from the group consisting of Cl to 11 C20 alkyl, secondary alkyl9 branched alkyl, tertiary alkyly 12 cycloalkyl, nap~thenic~ aryl~ aralkyl9 alkenyl and allyl 13 groups. Typical; but non-limiting examples are (C6H13~2 Mg, 14 (s-Bu)2Mg, (t-Bu~Mg~ Et?Mg, ~iPr~2Mg~ (n BU)2Mg~ dibenzyl Mg, dicrotyl Mg~ or ~n+S Bu~2Mg. Mixtures of diorgano-16 magnesium compounds ean be readily employed. The most l7 preferred organic groups are secondary ant tertiary alkyl 18 groups such as tertiary or sec-butyl.
19 Additionally~ Lewis bases c~n be employed in the com~ination wi~h the me~al halide of Alj Ga and In, the di~
21 organomagnesium compound and/or the Group IVB-VIII tr~nsi~
22 tion metal compound as long as they do not cause excessive 23 cleavage of metal carbon bonds or los~ of ac~i~e si~s~
24 wherein the Lewis base is seleeted from the group consisting of tertiary amines, esters9 phosphines9 p~osphines oxides, 26 p~osphates (alkyl + aryl) p~osphites9 hexaalkyl phosphori~
27 triamides, dimethyl sulfoxide, dimethyl ~ormamide, secondary 28 amines, dis~kyl ethers 9 epoxides, ~aturated and unsaturated 29 heterocycles, or cyclic ethers, and mixtures ~hereofO
Typical but non-l~miting examples are diethyl ether, tri 3l ethyl amine, ethyl benzoate, diisopentyl ether or tetra-32 hydrofuran.

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1 Magnesium salts may also be employed with the 2 instant catalysts if they are partially or wholly solubil-3 ized by reaction with the alkyl me~al components. Non-4 limiting examples include MgBr2, ClMgOR", R"OMgO0CR", Mg(OR")2, and the like.
6 The molar ratio of the metal halide compound to 7 the diorganomagnesium compound is critical and is 0.5Cl to 8 2:1, more preferably about lolo Ihe number of moles of 9 Lewis base can vary widely but is preferably equal to or less than the sum of the moles of the metal halide compound 11 and the diorganomagnesium compound The molar ratio of the metal halide compound or the diorganomagnesium compound to pre, fe rab/y 13 the transition metal compound isAless than 20~1 and more 14 preferably less than 10.1~
Also; additional dialkyl aluminum halide type 16 cocatalyst can be employed for further modification of poly-17 merization activityO Diethyl aluminum chloride is a typical, 18 but a non-limiting exampleO
19 The catalyst system of the invention enables the process for making alpha olefin polymers having a high de-21 gree of isotactic stereoregularity to be carried out at a 22 temperature o~ 25 to about 150C~, more preferably 40 to 23 80C. at pressures of 1 atm to 50 atm. The reaction time 24 for polymerization is 0.1 tO 10 hours, more pre~erably 0.5 ~o 3 hoursO Due to the high catalyst activity, 26 shorter times and temperatures below 80C can be readily 27 employed.
28 The reaction solvent for the system can be any ~ inert paraffinic, naphthenic or aromatic hydrocarbon such as benzene~ toluene, xylene, propane, butane, pentane, 31 hexane, heptane, cyclohexane, and mixtures thereof. Prefer-32 ably, excess liquid monomer is used as solvent. Gas phase 11~57~P

1 polymerizations may also be carried out with or without 2 minor amounts of solvent~
3 Typical, but non-limiting examples of C2-C20 alpha-4 olefinic monomers employed in the present invention for the manufacture of homo-, co- and terpolymers are ethylene, 6 propylene, butene-l, pentene-l, hexene-l, octadecene-l, 7 3-methylbutene-l, styrene, vinylidene norbornene, l,5-hexa-8 diene and the like and mixtures thereof. Isotactic polymer-9 ization of propylene and higher olefins is espcially pre-ferred.
11 The metal halide compound and diorganomagnesium 12 compound can be added separately to the reactor containing 3 the transition metal compound but are preferably premixed 4 before addition to the reactor~ Employing either the metal halide compound or the diorganom~gnesium compound alsne with 16 the transition metal compound does not provide the improved 17 catalyst efficiency and stereospecificity as envisioned in 8 this application. In order to attain this, it is necessary 19 to employ both the metal halide compound and diorganomagnes-ium compound in combination with the transition metal com-21 pound in the cri~ical proportions as previously defined.
22 The concentration of the transition metal in the polymer-23 ization zone is O.OOl to 5 mM, preferably less than Ool mM.
24 DETAILED DESCR~PTION

26 Polymerizations were carried out in a 1 liter 27 baffled resin flask fitted with an efficient reflux conden-28 ser and 8 high speed stirrer. In a standard procedure for ~ propylene polymerizations, 475 ml n-heptane (~l ppm water~
containing lOmmoleEt2AlCl (1.20 g), or the mixture of 31 cocatalysts, wa~ charged to the reactor under dry ~2 heated 32 to reaction temperature (65~C) and saturated with pure pro-~573~

1 pylene at 765 mm pressure. The TiCl3 (l.00 g) (6.5 mmole) 2 was charged to a catalyst tube containing a stopcock and a 3 rubber septum cap. Polymerization started when the TiCl3 4 was rinsed into the reactor with 25 ml n-heptane from a syringe. Propylene feed rate was adjusted to maintain an 6 exit gas rate of 200-500 cc/min at a pressure of 7~5 mm.
7 After one hour at temperature and pressure, the reactor 8 slurry was poured into one liter isopropyl alcohol, stirred 9 2-4 hours, filtered, washed with alcohol and vacuum dried.
The TiCl3 was prepared by reduction of TiCl4 with 11 Et2AlCl followed by treatment with diisopentyl et~er and 12 TiCl4 under controlled conditions, yielding a high surface 13 area delta TiCl3 having low aluminum content.
14 The sec-butyl magnesium in Runs B, D and E was obtained from Orgmet and contained 72% non-volatile material 16 in excess of the s-Bu2Mg determined by titration. IR, NMR
17 and GC analyses showed the presence of butoxide groups and 18 0.07 mole diethyl ether per s-Bu2Mg. A second sample of 19 (s-Bu)2Mg was used in Runs G and I. It was substantially pure s-Bu2Mg but contained O r 33 mole diethyl ether per 21 s-Bu2Mg.

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l Comparison of runs B, ~9 E, G and I with their 2 respective control runs A9 C~ F and H shows that each type 3 of ~iC13 catalyst the novel cocatalyst combination gave 2~10 4 times higher activity than t~e customary Et2AlCl cocatalyst.
The percent heptane insolubles (% HI) decreased 6 substantially using the new cocatalysts. Thus, these high 7 activity catalysts are attractive for making low crystallinity 8 homopolymers of propylene and higher alpha olefins~ They are 9 particularly attractive for making thermoelastic polymers and amorphous copslymers and ~erpol~mers for elastomersO

12 A titanium catalyst containing MgC12 was prepared 13 by dry ball milling 4 days a mixture of anhydrous MgC12 14 (1 mole), TiC14 (1 mcle) and ~TiC13 ~0.1 mole). Propylene lS was polymerized using the conditions in Example 19 Run B
16 and the quantities shown in Table 2. Activity with t~e co~
17 catalysts of this invention ~Run L) was intermediate between 18 those of the AlEt3 ar,d AlEt~Cl controls (Runs J and K), but l9 the stereospecificity as ~hown by /0 HI was much higher than the controls. ~he large increase in % HI obtained with this 21 MgCL2~containing catalyst is in contrast to the results in 22 Example 1 using TiC13 catalysts in which aetivity increased 23 sharply but ~/0 HI decreasedO
24 TABLE Il Alkyl Rate 26 _ Run Catal~ Metals_ ~Lg_Cat¦hr % HI
27 J(Control) 1 10 AlEt3 79 54.4 28 K(Control) 1 10 AlEt2C1 18 3508 29 L 0.2 1 AlEtC12 + 42 81.0 1 ~s~Bu)2Mg 32 A titanium catalyst was prepared by dry ball

- 10 -5~73~
1 milling 4 days a mixtu1^e of 5 MgCl29 l TiCl4 and l ethyl 2 benzoa~e, heating a slurry of the solids in neat TiCl4 2 3 hours at 80C, washing with n-heptane and vacuum drying.
4 The catalyst contained 3.7~V/o Ti.
Propylene was polymerized following the procedure 6 of Example l, Run B. As shcwn in Table III~ all the control 7 runs (M through S~ gave subs~.antially lower activity and/or 8 % HI than the AlEtCl2 + Bu2Mg combination (Run T) or AlCl 9 Bu2Mg (l~un V~.
If the new cocatalysts simply reacted as the

11 separate alkyl metals compounds9 the results should have

12 been like Runs M -~ QO If the new cocatalysts simply reacted

13 according to the equation. AlRGl2 ~- R2~1g~ AlR~Cl

14 RMgCl, ~hen the results should have been like Runs N ~ P~
However, the results in Run T and U are dramatically better, 16 showing a remarkable synergism Sr H ~1 ~) u~
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1 A much smaller synergistic effect was obtained by 2 combining AlEt2Cl ~ Bu2Mg (Run S), but the results were 3 poorer than those obtained with AlEt3. Combining Eu2Mg with 4 AlEt3 (Run R) destroyed the activity shown by AlEt3 alone (Run 0). Thus9 the outstanding results were obtained only 6 when R2Mg was combined with RAlC12 or AlC13.

8 The procedure of Example 3 was followed using 0.2 9 g of the MgC12~containing catalyst together with (s-Bu)2Mg and variations aluminum compoundsO

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1 Compar:isol~ of Runs Vi W and X shows that the 2 highest % I~I is obtained at approximately equimolar amounts 3 of RAlC12 and R2Mg (R~m V), that a large excess of RAlC12 4 is undesirable (Run W) and that a small excess of R2Mg increases activity (Run X). Activity also increased upon 6 addition of AlEt2Cl to the AlEtC12~(s~Bu)2Mg system (Run Z).
7 The remainder of the experiments show that the dibromide may 8 be used in place of dichlGride (Run M~, that long chain 9 alkyl aluminum compounds are very effective (Run BB), but that dialkyl amide groups on the aluminum compound destroy 11 catalyst activity (Runs CC and DD).

13 The procedure of Example III9 Run T was followed 14 except that Lewis bases were also added ~o the AlEtC12-(s-Bu)2Mg cocatalysts.
16 Addition of Lewis bases causes a decrease in 17 cata1yst activity until it becomes zero at a mole ratio of 18 one strong base per mole of RAlC12 ~ R2Mgo

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- 16 -1 As sho~ in Run EE, small quantities of Lewis base 2 are effcctivc in improvin~ isotacticity (94~3/O HI vs. 9l.9 3 in Run T~ while maintaining high activity (nearly 9 times 4 the conventional ~lEt2Cl/TiCl3~0.33 AlCl3 catalyst, Run H).
EXAMP~E 6 6 The procedure of Example III, Run T was followed 7 except that xylene diluent was used for polymerization in-8 stead of n-heptane. Activity was 676 g/g Cat/hr and the 9 polymer gave 90O9% heptane insolubles t EX~M2LE 7 11 The procedure of Example 3, Run T was followed 12 e~cept that polymerization was carried out at 50C and 13 80C. Both polymerizatiorl rate and % HI decreased with 14 increasing temperature9 with the largest decrease taking place above 65C.

17 Polymer Time9

18 Run Temp~ C Hours Rate % HI

19 II 50 l 474 90.4 T 65 l 367 9l.9 21 JJ 80 0.5 148 74.6 23 Propylene was polymerized at 690 kPa pressure in 24 a stirred autoclave at 50C, l hour. A second preparation of MgCl2~containing TiCl4 catalyst (2 t 68% Ti) made as in 26 Example 3 except that TiCl4 ethylbenzoate complex-was pre-27 formed, was used in combination with Al~Cl2~R2Mg. High 28 stereospecifici~y was obtained at higll rates and catalyst ~ efficiencies.

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TA~T~ VII
2 g l~lmoles Mmoles 3 Kun Cat Al~tC12 (S-liU2?~Rate % HI
4 I~l~O ~ 10 0 ~ 5 0 ~ 51672 88 ~ ~3 LL O.lO 0 D 25 0 ~ 25696 95 ~ O

~ The procedure of Example 3, Run T was followed 8 except that the catalyst of Example 8 was used and 1 mmole 9 dL-n-hexyl magnesium was used instead of 0083 ~mole (s~Bu)2 Mg. The (n hexyl)2Mg in Soltrol #L0 was obtained from Ethyl 11 Corporation (Lot No, B~516~o Polymerization rate was 551 12 g/g Cat/hr and the polymer gave 76.9 % HI.
13 EX~MPLE 10 14 The procedure of Example 59 Run EE was followed except that the cataLyst of Example 8 was used~ 0~ 5 rnmole 16 diethyl ether was used in place of ethylbenzoate5 and 17 Lithium Corporaticn (n + s Bu)2Mg in hexane was used in 18 place of (s-Bu~2Mgc Rate was 327 g/g Cat/hr and V/o HI -19 91.8.
EXAMPLE ll .... .
21 The procedure of Example lO was followed except 22 that a new pure sample of (sec-Bu)2Mg was used with 0.33 23 mole diethyl etherO Rate was 268 g/g Cat/hr and /0 HI =
24 92.2.
EXAMPLE l~
_ _ 26 A catalyst was prepared by dry ball milling 4 days 27 a mixture of lO MgCl2, 2 TiCl~ 2 ethylbenzoate and l Mg 28 powder, heating the solids in neat TiC14 2 hours at 80C, washing with n-heptane and vacuum drying (Ti ~ 2.16%).
Propylene was polymeri2ed l hour at 65C and 31 a~mospheric pressure using 0c20 g of this catalyst under 32 t~e condi~ions of Example 3, Run r except only 0.4 m~lole 1 1 ~ 5~7~

1 (s-Bu)~lg and 0.4 mmole AlEtC12. Rate was 240 g/g Cat/hr 2 and % HI = 93,9, 4 A catalyst was prepared by dry ball milling 1 day a mixture of 5 MgC12 and 1 ethylbenzoate,, adding 1 TiC14 6 and milling an additional 3 days, then treating the solids 7 with neat TiC14 2 hours at 80C, washing with n-heptane and 8 vacuum drying (3.44 U/o Ti).
9 Propylene was polymerized following the procedure of Example 3, Run T, except that 1 mmole (s-Bu)2Mg was used ll instead of 0.83 n~ole. Rate ~as 298 g/g Cat/hr and /0 HI =
12 89~
13 EXA~ JF~_14 14 Following the procedure in Example 8, two catalysts were made at different Mg/Ti ratios. Catalyst A was made 16 with 1 MgC12 ~ 1 TiC14-ethylbenzoate and B S2.10% Ti~ was 17 made with 10 MgC12 ~ 1 TiCl~-ethylbenzoate complex. Pro-l8 pylene was polymerized following the procedure of Example 3, 19 Run T ~Table 8).
TABLE VIII
21 gMmoles Mmoles 22 Run CatAlEtCl? tS-BL~-M~ Rate ~! HI
23 MM 0.107A2 1.66 60 72.0 24 NN 0.316B0.25 0~25 512 60~4 00( )0.316B0.25 0.25 124 84.2 26 (a) Added 0.25 mmole triethylamine to the alkyl 27 metal cocatalysts.

28 Sin~e many modifications and variations of the 29 invention may be made wi~hout departing from the spirit or scope of the invention thereof, it is not intended to limit 31 the spirit or scope to the specilic examplcs thereof.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved catalyst composition adaptable for use in an alpha-olefin polymerization which includes a mixture of:
a) Group IVB to VIII transition metal compound;
b) a metal di- or tri- halide compound, a metal of said compound being selected from the group consisting of Al, Ga and In; and c) a diorganomagnesium compound having the formula:
R R'Mg wherein R and R' can be the same or different and are selected from the group consisting of secondary or tertiary alkyl groups;
the molar ratio of said metal di- or tri- halide compound to said diorganomagnesium compound being from 0.5:1 to 2:1.
2. The composition of claim 1, wherein said metal halide compound is selected from the group consisting of R''WX2, R''WXY and mixtures thereof, wherein W is said metal, X is selected from the group consisting of chloride and bromide, Y is selected from the group consisting of chloride, bromide and an anion incapable of initiating olefinic polymerization, and R'' is selected from the group consisting of alkyl, cycloalkyl, branced alkyl, naphthenic and aralkyl groups.
3. The composition of claim 1, or claim 2, wherein the molar ratio of said metal di- or tri- halide compound to said diorganomagnesium compound is 1:1.
4. The composition of claim 1 or claim 2, wherein the molar ratio of the metal di- or tri- halide compound or the diorganomagnesium compound to the tran-sition metal compound is less than about 20:1.
5. me composition of claim 2, wherein said anion is selected from the group consisting of alkoxide, phenoxide, thioalkoxide and carboxylate.

6. The composition of claim 1, wherein said transition metal compound is a transition metal halide.
7. The composition of claim 6, wherein the halide of said transition metal halide is selected from the group consisting of chloride, bromide and mix-tures thereof.
8. The composition of claim 7, wherein a metal of said transition metal halide is selected from the group consisting of trivalent titanium, tri-valent vanadium and tetravalent titanium.
9. The composition of claim 8, wherein said transition metal compound is TiCl3.
10. The composition of claim 9, wherein said TiCl3 is on a support.
11. The composition of claim 10, wherein said support is MgCl2.
12. The composition of claim 10, wherein said metal halide is EtAlCl2 and said diorganomagnesium compound is (s-Bu)2Mg.
13. The composition of claim 11, further including TiCl4 on said MgCl2.
14. The composition of claim 9, further including TiCl4.
15. The composition of claim 14, wherein said TiCl4 is on a support.
16. The composition of claim 15, wherein said support is MgCl2.
17. The composition of claim 16, wherein said metal halide is EtAlCl2 and said diorganomagnesium compound is (s-Bu)2Mg.
18. The composition according to claim 1, further including a Lewis base.
19. The composition according to claim 1, further including a dialkyl aluminum halide.
20. An improved process for the polymerization of C2 to C20 monomers and mixtures thereof to solid homo-, co- or terpolymers by contacting said mono-mers with a catalyst system including:
a) A group IVB-VIII transition metal compound;

b) A di- or tri- metal halide compound, a metal of said compound being selected from the group consisting of Al, Ga and In; and c) A diorganomagnesium compound having the formula:
R R'Mg wherein R and R' can be the same or different and are selected from the group consisting of secondary or tertiary alkyl;

the molar ratio of said metal di- or tri- halide compound to said diorganomagnesium compound being from 0.5:1 to 2:1.
21. The process according to claim 20, wherein said metal halide compound is selected from the group consisting of R "WX2, R "WXY and mixtures thereof, wherein W is said metal, X is selected from the group consisting of chloride and bromide, Y is selected from the group consisting of chloride, bromide and an anion incapable of initiating olefinic polymerization and R'' is selected from the group consisting of alkyl, cycloalkyl, branched alkyl, naphthenic, aryl and aralkyl groups.
22. The process of claim 20, or claim 21 wherein the molar ratio of said metal di- or tri- halide compound to said diorganomagnesium compound is 1:1.
23. The process of claim 20, or claim 21, wherein the molar ratio of the metal di- or tri- halide compound or the diorganomagnesium compound to the transition metal compound is less than about 20:1.
24. The process according to claim 21, wherein said anion is selected from the group consisting of alkoxide, phenoxide, thioalkoxide, and carboxylate.25. The process according to claim 20, wherein said transition metal compound is a transition metal halide.
26. The process according to claim 25, wherein the halide of said transition metal halide is selected from the group consisting of chloride, bromide and mixtures thereof.

27. The process according to claim 26, wherein a metal of said trans-ition metal halide is selected from the group consisting of trivalent titanium, trivalent vanadium and tetravalent titanium.
28. The process according to claim 27, wherein said transition metal compound is TiCl3.
29. The process according to claim 28, wherein said TiCl3 is on a support.
30. The process according to claim 29, wherein said support is MgCl2.
31. The process according to claim 27, wherein said metal halide is EtAlCl2 and said diorganomagnesium compound is (s-Bu)2Mg.
32. The process according to claim 30, further including TiCl4 on said MgCl2.
33. The process according to claim 28, further including TiCl4.
34. The process according to claim 20, wherein said tiCl4 is on a support.
35. The process according to claim 34, wherein said support is MgC12.
36. The process according to claim 35, wherein said metal halide is EtAlCl2 and said diorganomagnesium compound is (s-Bu)2Mg.
37. The process according to claim 20, further including a Lewis base.
38. The process according to claim 20, further including a dialkyl aluminum halide.
39. The process according to claim 20, wherein said metal halide com-pound and said diorganomagnesium compound are premixed.