CA1160206A - Process for the copolymerisation of ethylene with polyunsaturated hydrocarbons - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Ethylene is copolymerized with high yields with polyunsaturated hydrocarbons by employing a catalytic system comprising a metallicorganic compound of a metal of the Third Group of the periodic System and a compound which is obtained by reacting metallic Mg, or Mn, with a Ti compound and a halogen donor.

Description

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This invention relates to an improved process for the high-yield preparation of copolymers starting from ethylene either alone or in mixture with one or more alpha-olefines, and a compound containing two or more unsaturated olefine ~onds, which can be conjugated, the process comprising the use of a catalytic system consisting of i) an organometalllc compound of group III of the periodic system, and ii) a compound prepared by reacting magnesium metal or maganese metal vapour whith a titanium compound and a halogen donor.
The products deriving from the copolymerisation of ethylene alone with the polyunsaturated compound are in the form of crystalline polymers.
The applicant knows of the existence of various processes for preparing crystalline copolymers deriving from the polymerisation of ethylene with a conjugated or non-conjugated polyolefine, and in particular butadiene and ethylidene-norbonene (see for example Canadian Pat. N
1.043.943, Pat.Nl.046.697, Pat.Appln. N282.224).
These processes are based on vanadium-based coordinated anionic catalysts which,-although giving high polymerisation yields, do not attain catalytic activity levels such as to obviate the need for the difficult purification of the copolymer from the transition metal residues, which damage the oxidation stability of the copolymer, and which produce an undesirable colour. The applicant is also aware of the Canadian Pat. Appl. N270.122 relating to a catalytic composition which is extremely active in polymerising and copolymerising mono alpha-olefines, and is prepared by reacting an organometallic compound of group III of the periodic system with a composition prepared by i) vaporising or subliming magnesium under vacuum, and ii) condensing this vapour into a condensed phase comprising a titanium tetrahalide ~6(~2~6à

and a halogen donor.
The same patent application states that the activity of the catalytic composition in the homo and copolymerisation of ~-olefines is extremely high when the quantity of magnesium metal vaporised is such as to give an atomic Mg/Ti ratlo mueh exceeding 0.5 in the condensed phase, and a eompound is present therein which is able to yield up halogen to the ma~nesium metal in excess of the atomic Mg/Ti ratio of 0.5 corresponding to the complex MgX2.2TiX3 (X = halogen). In this manner, there is further formation of MgX2, which interacts with the stoiehio-metrie complex to give a new and more active eomplex containing titanium. We have now discovered that by suitably modifying the magnesium vaporisation conditions and choosing the reagents and reaction conditions, it is possible to eopolymerise ethylene, either alone or in mixture with other alpha-olefines, with a compound eontaining one or more unsaturated olefine bonds, to give highly crystalline polymers if ethylene is used alone.
Manganese can also be .. .....

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- used for preparing the catalytic composition, in addition to magnesium.
Thus, the present invention pxovides a catalyst effectiye in the high-yield copolymerization of ethylene or a mixture of ethylene and another ~-olefin with a polyolefin selected from the group consisting of cyclic and alicyclic hydrocarbons containing more -than one double bond, optionally conjugated, comprised of (1) a composition prepared by reacting a metal vapour with a titanium compound and a halogen donor, said metal vapour being selected from magnesium metal vapour and manganese metal vapour, and (2) an organometallic compound oE
group III of the periodic table,where.in said magnesium metal is sublimed under a vacuum between 2 and 10 ~ Torr and at a temperature between 300 and 650C, and said manganese metal is sublimed under a vacuum between 10 1 and 10 ~ Torr and at a temperature between 800 and 1100C.
In particular, the present invention provides a catalyst effec-tive in the high-yield copolymerization of ethylene or a mixture of ethylene and another ~-olefin with a polyolefin selected from the group consisting of cyclic and alicyclic hydrocarbons containing more than one double bond, optionally conjugated, comprised of (lj a composition prepared by reacting a metal vapour with a titanium compound and a halogen donor, said metal vapour being sel~cted from magnesium metal vapour and manganese metal vapour, and ~2) an organoalu~
minium compound, wherein said magnesium metal is sublimed under a vacuum between 2 and 10 4 Torr and at a temperature between 300 and 650C, and said manganese metal is sublimed under a vacuum between 10 1 and 10 4 Torr and at a temperature between 800 and 1100C. `
The present invention in another aspect also provides in a process for the high-yield copolymerization o~ ethylene or a mixture o~ ethylene with another ~- olefinewit~ a polyolefine selected from the group consis:ting o~ cyclic and alicyclic hydro-carbons containlng more than one double band, optionally conjuga-ted, which comprises contacting the comonomers with a catalyst as defined above. In accordance with this process, ethylene may be copolymerized with 1,3-butadiene or with ethylidinenorbornene (5-ethylidine(2,2,1)-bicyclohepta-2-ene). The polymerization reaction may be carried out in the presence of an inert solvent;
- the inert solvent may be the same as used for preparation of compon.ent (1) for the catalyst. The polymerization may be carried out at a temperature in the range between ambient tempexature and a temperature slightly less than the melting point of the copolymer and at a pressure of 1 to 30 atmospheres . The pol~merization may for example be carried out at a temperature between ~0 and 120C and at a pressure of between 1 and 20 a-tmospheres. The comonomers may be fed in a gaseous state to the catalytic system in the absence of solvents. The catalytic composition may be disposed on an inert support.

The activity of the catalytic system heretofore described in such as to produce a quantity of copolymer per g of titanium which is equal to or greater than 50 kg. The catalytic composition can be prepared by vaporising the magnesium or manganese either in their metal state or in the form of one of their alloys, and condensing the vapour into a cold solution prepared by dissolving a titanium compound and optionally a halogenated compound in a diluent, ~e.g. an inert diluent). The diluent may be an inert solvent selected from the group consisting of aliphatic or aromatic hydrocarbons.

The metal (M) can be used in powder form, in the form of granules or in lumps, and is preferably vaporised under vacuum by sublimation.
As indica-ted above in the case of magnesium, for a 3a -~ A;l 6~ZOG

pressure of between 2 and 10 Torr, th.e temperature.ya~ries,.as a function. of this latter, between:ahout.650 and 300C.
Manganese as indica.ted above requires more severe conditions, namely 800-1100C for 10 -10 Torr.
If the operation is carried out at a higher tempera-ture, the metal can be vaporised from its molten state even at atmospheric pressure. The solution into which the vapour is condensed is kept strirred at low temperature. In relation to the solvent used, this can be fixed in the range o~ -120 to 0C, and generally -80 to -20C. The use of an inert diluent, chosen from low volatility hydrocarbon solvents of low freezing point (e.g. n-heptane, n-octane, toluene, etc.) is not s-trictly necessary, as the reaction can be carried out even within the titanium compound and the halogenated compound in their pure state.
The titanium compound may be selected from the halides, alcoholates and organometallic derivatives of trivalen-t and tetrav~alent titanium.
The halogen donor may be selected from organic and . 20 inorganic halides, e.g. alkyl halides. In par-ticular, organic halogen donors may be selected from chloroalkanes, bromoalkanes, chloroarenes and bromoarenes.
Titanium tetrachloride represents a liquid titanium corpound sultable ~, /
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for this purpose, and the alkyl halides are suitable as the halogenated compounds, their measured excess then constituting the reaction medium.
Examples of alkyl haIides which can be used are 1-chlorobutane, 1-chlorohexane, and l-bromohexane, but secondary or tertiary alkyl halides and aryl or alkylaryl halides are also reactive. Of the inorganic halides, the most suitable have proved to be SnC14, SbC15, GeCl~ and POC13.
Of the titanium compounds, in addition to the tetra-chloride, effective use can be made of the other halides, including the trivalent halides, the alcoholates`~ halogen alcoholates, chelates and all the organometallic derivatives.
In practice, any titanium compound can be used, the difference between them being only the rate oE reaction.
The M/Ti ratio to be obtained in order to prepare extremely active catalytic compositions exceeds 0.5, and in particular > 4. The preEerred value for said ratio i9 between 15 and 30, and a further excess of M (Mg or Mn) does not con-stitu-te an advantage. The quantity of the halogen donor compounds present in the reaction is adjusted according to the quantity of M, with respect to which it should be in a ratio of > 2 in the case of mono-halogenated organic compounds, and > 1 in the case of inorganic compounds able to yield up more than one halogen atom per molecule. The reaction between the M vapour, the Ti compound and the halogenated compound already partly takes place at the aforesaid low temperature. For its completion, either a lonc~ period ~some days) of standing at ambient temperature is required, or, preferably, heating for a few hours (1-5), according to the chosen temperature (50-180~C). The reaction is faster when the halogen donor is inorganic.
The halogen donor is not strictly required in the '~1 .

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low temperature-maintained solu-tion into which the metal vapour is condensed. It can be added later, but before the solution is raised to a higher temperature for completing the reaction.
The fine suspension prepared as heretofore described is usually used directly as the catalytic component for the polymerisation, which will be described hereinafter, provided neither any excess of one of the reagents nor any reaction by-products substantially constitute disturbing agents in the formation of the catalyst. AIternatively, said suspension can be filtered and the solid resuspended in the dispersing agent considered most suitable, generally the same in which the polymerisation is carried out. Again, the solid compound can be dispersed on an inert solid support, constituted for example by the actual polymer which is to be produced.
As stated, the other catalytic componen-t is constituted by an organometallic compound of an element of the III group of the periodic system.
Of said elemen-ts, aluminium is that mostly used for reasons of effectiveness and convenience.
Examples of compounds used are the trialkyl and triaryl aluminiums such as Al(C2H5)3, Al(i-C3H7)3, Al(C6H5)3, the alkylaluminium hydrides such as Al(H) li-C3H7)2, and the alkyl and arylaluminium halides such as Al~C2H5)2Cl and ( 2 5) 2 The trialkyl derivatives are preferred, but they are also very effective in mixture with the halogenated derivativès.
The molar ratio of the organometallic compounds to the titanium compound must exceed 3 in order to attain maximum specific activity.
For practical reasons, said ratio is kept very high, for example between 100 and 500, in consideration of the fact .~ j .

2(~6 that extremely small quantities of the titanium compound are used in polymerisation. As stated, the copolyme-risation process according to the present invention is based on the copolymerisation of ethylene with a conjugated or non-conjugated polyolefine, and uses the aforesaid catalytic components in the presencè of an inert diluent, at a temperature of between 40 and 120C and an operating pressure of between 1 and 20 Kg/cm2.
In batch tests, the reagents are fed into the reactor such that the catalyst either forms in the presence of the mixture of the two monomers or comes into contact with it.
In practice, there are two methods of operation, both of which are effective. In the first, the catalytic component containing the titanium is introduced last, while in the second the reaction between the catalytic components to be added successively to the monomer mixture is carried out separately. In this latter case, there is a precontact time which, although not critical should not be very prolonged, in particular when a high Al/Ti ratio is used.
The aliphatic hydrocarbons are preferably used as the inert diluents. However, the presence of a diluent is not strictly necessary during the polymerisation stage, as it is possible to operate in the gaseous state by introducing the catalyst dispersed in a little low boiling solvent.
The monomers which the applicant has chosen for exempli~fiying the copolymerisation process are those listed below. The conditions detailed heretofore are absolutely general, and all types of ethylene copolymers can be prepared by applying the method of the present patent applica~ion, on the basis of the detailed teachings for the copolymers listed hereinafter, without leaving the scope of the invention. The expert oE
the art will be able to choose the most suitable operating :, ........................................... .

- ~L6~206 conditions in relation to the required polymer.
The monomers are ethylene on the one hand, and a cyclic or acicyclic hydrocarbon containing more than one unsaturated bond, which can be conjugated, on the other.
Prototypes o~ these elasses oE hydroearbon preferred for their reactivity and low cost are 1,3-butadiene and 5-ethylidene-(2,2,1)-dieyelohepta-2-ene (ethylidenenorbonene).
They have a reactivity under polymerisation whieh is less than that of ethylene, because of which they are fed in excess (50 times or moxe? over the ~uantity of the same monomer which it is required to obtain in the copolymer.
This exeess is utilised by reeyeling its solution~
The practically useful ethylene eomonomer present in the eopolymer is ~ust a few per cent (less than 10 mol %).
The molecular weight of the eopolymer can be controlled by lntrodueing hydrogen, in addition to varying the reaction conditions. The copolymers prepared by the proeess aceording to the present invention have properties which vary with their composition. The ethylene-butadiene eopolymers contain trans unsaturated bonds, while cis and vinyl unsaturated bonds are absent or practically absent, as shown by a 1,4 trans addition of the butadiene units. The ethylene-butadiene eopolymers rieh in ethylene are charaeterised by densities between 0.9~0 and 0.960, melting points around 130C and an unsaturated bond distribution as shown by the aecompanying 13C-NMR spectrum (relative to a eopolymer eontaining 12.3 mol % of butadiene), in which three peaks can be seen attributable to differently struetured butadiene units along the polymer chain (peaks attributable to methylenes in the bu-tadiene~at a = 32.6, b = 32.7, and c = 32.9 ppm~. It should be noted that analogous eopolymers prepared by the said art show only -two of said three peaks in the C-NMR spec-trum. It is knownthat crystalline poly alphaolefines such as polyethylene, isotactic polypropy-lene, isotactic polybutene-etc. have been available commercial-ly for some time.
These polyalphaoleEines are constituted either by homopolymers or by copolymers with small quantities of a second alphaolefine in order to solve certain technical problems.
The quantity of the second olefine is normally so low as not to excessively reduce the crystallinity with respect to the homopolymer, as certain important mechanical character-istics such as the modulus, ultimate tensile strencJth ètc.
are associated with -the high crystallinity.
In copolymers of ethylene with butadiene, the compatibility of units of the two types in the same crystal enables substantially crystalline polymers to be obtained over the entire range of compositions from pure polyethylene to pure trans polybutadiene. In this case, there is therefore not the limitation which exists in the case of copolymers of -the monoalphaolefines, in which an olefine must be contained in a very small quantity in the copolymer in order to maintain crystallinity at a high level. An extremely important advantage of the copolymers prepared according to the process of the present patent is related to the fact that they contain unsaturated bonds (either in the main chain as in the case of butadiene, or in the side groups as in the case of ethylidenenor-bonene).
By means of these unsaturated bonds, the copolymer can be easily cross-linked (with sulphur or other reagents) to further improve its technical characteristics such as thermal resistance, impact strength or resistance to agents which induce the formation of environmental stress cracking.
The unsaturated bonds also allow certain transforma-tions which wouId otherwise be difficuIt if not impossible, ~0~06 such as foaming and the thermoforming of sheets.

The catalytic co~ponent containing titanium is prepared in a 1 litre horizontally disposed rotating glass ~lask, at the centre o~ which is placed an aluminium crucible heated electrically by means of a tungsten filament.
240 ml of n-heptane and 0.2 ml of TiC14 were placed in the flask and 0.9 g of magnesium shavings were placed in the crucible. The solution was cooled to -70C.
After putting the rotating apparatus under vacuum (10 3 Torr), the crucible was heated by applying an electric voltage across the ends of the filament of suE~icient intensit~
to heat it to red hea-t.
Vaporisa-tion of the Mg led to the formation of a brown suspension, to which n-butyl chloride (l-chlorobutane, 8.2 ml) was added after nullifying the vacuum by introducing nitrogen.
The suspension was then heated for 3 hours at 80C, using a reflux condenser.
Copolymerisation A stainless steel autoclave having a capacity of 5 litres and fitted with a mechanical stirrer and controlled electric heating was put under vacuum,.and a prepared solution consisting of:
anhydrous n-heptane 2200 ml butadiene 200 g ~l(C2H5)3 15 mmoles was then introduced by suction.
The temperature of the autoclave was controlled at 70C before feeding hydrogen and ethylene into it at partial pressures of 3.5 and 4.5 Kg/cm2 respectively.
10 ml of the heptane suspension prepared as heretofore described and containing 0.075 mmoles of titanium ~6~2(~6 .

were fed into the autoclave, with an ethylene overpressure, using a 100 ml steel phial provided with a feed valve and discharge valve.
A heptane solution (50 ml) of Al~C2H5~C12 (7.5 mmoles) was then added during the first five minutes of reaction to the mixture already presen-t in the autoclave, using a piston pump.
An immediate absorpti.on oE ethylene was observed, and this was fed continuously so as to maintain the initial pressure constant at a temperature of 70C.
After 3 hours it wa.s found that the ethylene was still absorbed with an intensity approximately equal to the initial intensity. The tes-t was however interrupted, and the suspension contained in the autoclave was discharged and :Eiltered.
388 g of dry polymer were obtained, having a MFI2 16 of 49.5, a butadiene unit content (moles~ of 3.3% and a melting point (Tm), determined by differential thermal analysis, of 131C. The polymer, which had the appearance of a white solid very similar to the appearance of a polyethylene, was mixed with the following compounds (g per 100 g of polymer):
zinc oxide 5 stearic acid 2,2'-methylene-bis(~-methyl-terbutylphenol) (AØ2246) N-oxydiethylbenzo-thioazole-2-sulphenamide (NOBS special) 1.5 dibenzothiazyl disulphide (Vulkacit DM)(Trademark~ 0.5 sulphur 3 The mixture was treated in a press at 180 for 30 minutes, to give a product having 40% of residue after extraction with boiling xylols (the polymer as such was ~ completely so].uble).

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Z~)6 A test was carried out at 85C using the autoclave and method described in example l.
In this case, the partial pressures of ethylene and hydrogen were 5 and 3 Kg/cm2 respectively, and 250 g of butadiene was introduced.
All the other quantities were as in example 1.
After 3 hours of polymerisation, 250 g of dry copolymer were obtained having the following characteristics: butadiene its = 3 3% (moles), MFI2 16 = 0.84 MFI21.6/ 2.16 melting point - 129Cr impact strength = 13.7 Kg/cm2.
When cross-linked as described in example 1, the product obtained had an impact strength of 50.4 Kg/cm2.

A polymerisation test was carried out employing the same apparatus and method of the preceding examples, using the following reagents:
- n-heptane 1840 ml butadiene 102 g Al(C2H5)3 17.6 mmoles H2 3.5 Kg/cm2 ethylene 5.0 "
Ti complex (see ex.l) 0.06 mmoles The autoclave was maintained at 85C both during gas introduction and during polymerisation, in the course of which the consumed ethylene was made up.
After 4 hours the test was interrupted, and the product was filtered off and dried, to give 285 g.
Analysis gave the following results:
butadiene units = 1.5% (moles), MFI2 16 = 0 99 g/10 min., MFI21 6 = 27-4, Tm (DSC) = 133C

~ .

~L~6~ 2~6 A solution prepared from 400 ml of n~heptane and ~0 ml of bicyclo(2,2,1)-5-ethyledine-2-heptene ~ethylidenenor-bornene) was sucked into a stainless steel autoclave o-~ the type described ln examplc 1, but l~aving a capacity o~ 2 litres.
The autoclave was temperature controlled at 85C, and ethylene and hydrogen were then introduced at partial pressures of 5 and3.;Kg/cm2 respectively.
The catalyst, consisting of a heptane suspension of the product obtained by reacting 5 mmoles of Al(i-C4~19)3 with 0.012 mmoles of titanium in the form described in example 1 or 60 minu~es at ambient temperature, was then introduced using a steel phial and a N2 overpressure.
The test lasted for one hour, during which the consumed ethylene was made up so as to maintain its partial pressure constant. The solid product obtained by filtering the suspension`and drying weighed 35 g.
It had the following characteristics: 3.3% of ethylidenenorbornene (weight), MFI2 16 = 3 4 g/10 min., MFI21 6 = 33~ =-0.9633 g/cm3.

The catalytic component containing titanium was prepared in a manner similar to that described in example 1, but start.ing from the following reagents:
l-chlorooctane 120 ml TiC14 0.088 ml manganese metal . 1.5 g The solution was cooled to -50 and a vacuum of 10 4.Torr applied, after which the manganese was vaporised and condensed. A dense dark brown-suspension was.obtained, which was.then heated to 100C for one hour.

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Chem.ical analysis showed that the homogenised suspension contained 5.10 mmoles/l of Ti, 186.2 mmoles/l of Mn, 390.0 mmoles/l of Cl.
Copolymerisation A copolymerisation test between butadiene and ethylene was carried out using the apparatus described in example 1.
The solution fed into the reactor was prepared from:
n-heptane 2200 ml butadiene . 250 g Al(i-C4Hg)3 22.5 mmoles After controlling the. temperature at 85C, the autoclave was pressurised with 3 Kg/cm2 of hydrogen and 5 Kg/cm2 of ethylene.
. 15 cm3 of the suspension containing the titanium complex prepared as here-tofore described were then introduced.
Further ethylene was added for 3 hours in order to maintain the pressure at the initial value of 10 Kg/cm2 at 85C, after which the test was interrupted, and the product filtered off and dried.
200 g of polymer were obtained having the following characteristics: 1,4 trans butadiene units 5.15% tmoles), MFI2 16 = 0 05 g/10 min., Tm (DSC) = 132C, ¦ n ~ (in decalin at 105) = 1.75.

The catalytic component containing titanium was prepared in an apparatus analogous to that described in example 1, from:
n-octane 300 ml TiC14 0.187 ml SnC14 8 ml Mg metal 1.2 g . L

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The magnesium was vaporised at 5.10 Torr and condensed into the solution, which was maintained at about The suspension obtained was raised to ambient tempera-ture. Af-ter 24 hours, the solution lying above the decanted solid was free from titanium, whereas the homogenised suspension contained 6.32 mmoles/l of Ti, 187 mmoles/l of Mg, 207 mmoles/l of Sn and 863 mmoles/l of Cl.
Copolymerisation The test was carried out in the autoclave described in example 1 at 85C, using the same method and the same reagents as example 5, with the exception of the catalytic component containing titanium, which this time consisted of 11.85 ml of the aforesaid suspension. The polymer obtained weighed 180 g and showed the following properties:-MFI2 16 =
0.1 g/10 min., Tm = 131C (DSC), butadiene units = 3.34%
(moles).

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Claims (39)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a process for the high-yield copolymerization of ethylene or a mixture of ethylene and another .alpha.-olefin with a polyolefin selected from the group consisting of cyclic, and alicyclic hydrocarbons containing more than one double bond, optionally conjugated, the improvement which comprises contacting said comonomers with a catalyst comprised of (1) a composition prepared by reacting magnesium metal vapor with a titanium compound and a halogen donor, and (2) an organoaluminium com-pound, wherein said magnesium metal is sublimed under a vacuum between 2 and 10-4 Torr and at a temperature between 300 and 650°C.

2. The process of claim 1 wherein ethylene is copoly-merized with 1,3-butadiene.

3. The process of claim 1 wherein ethylene is copoly-merized with ethylidenenorbornene.

4. The process of claim 1 wherein said magnesium metal vapor is condensed into a diluent containing said titanium com-pound and optionally, said halogen donor.

5. The process of claim 4 wherein said diluent is an inert solvent selected from aliphatic or aromatic hydrocarbons and said condensation is maintained at a temperature between -120°C and 0°C.

6. The process of claim 1 wherein in the catalytic system the titanium compound is selected from the halides, alco-holates, halogenoalcoholates or organometallic derivatives of trivalent or tetravalent titanium.

7. The process of claim 1 wherein the halogen donor is selected from organic or inorganic halides.

8. The process of claim 7 wherein the organic halogen donor compound is selected from chloroalkanes, bromoalkanes, chloroarenes and bromoarenes.

9. The process of claim 3 wherein the molar ratio of the organic halogen donor compound to the vaporized metal is equal to or greater than 2.

10. The process of claim 7 wherein the inorganic halogen donor compound is selected from SnCl4, SbCl4, GeCl4 and POCl3.

11. The process of claim 10 wherein the molar ratio of the inorganic halogen donor compound to the vaporized metal is equal to or greater than 1.

12. The process of claim 1, wherein component (1) of the catalytic system is prepared by reacting the vaporized metal with the titanium compound in a M/Ti ratio equal to or greater than 4, M being metal.

13. The process of claim 12, wherein said M/Ti ratio is between 15 and 30.

14. In a process for the high-yield copolymerization of ethylene or a mixture of ethylene and another .alpha.-olefin with a polyolefin selected from the group consisting of cyclic and alicyclic hydrocarbons containing more than one double bond, optionally conjugated, the improvement which comprises contacting said comonomers with a catalyst comprised of (1) a composi-tion prepared by reacting manganese metal vapor with a titanium compound and a halogen donor, and (2) an organoaluminium compound wherein said manganese metal is sublimed under a vacuum between 10 1 and 10 4 Torr and at a temperature between 800 and 1100°C.

15. The process of claim 14 wherein ethylene is copoly-merized with 1,3-butadiene.

16. The process of claim 14 wherein ethylene is copo-lymerized with ethylidenenorbornene.

17. The process of claim 14 wherein said manganese metal vapor is condensed into a diluent containing said titanium compound and optionally, said halogen donor.

18. The process of claim 17 wherein said diluent is an inert solvent selected from aliphatic or aromatic hydrocarbons and said condensation is maintained at a temperature between -120°C and 0°C.

19. The process of claim 14 wherein in the catalytic system the titanium compound is selected from the halides, alco-holates, halogenoalcoholates or organometallic derivatives of trivalent or tetravalent titanium.

20. The process of claim 14 wherein the halogen donor is selected from organic or inorganic halides.

21. The process of claim 20 wherein the organic halogen donor compound is selected from chloroalkanes, bromoalkanes, chloroarenes and bromoarenes.

22. The process of claim 21 wherein the molar ratio of the organic halogen donor compound to the vaporized metal is equal to or greater than 2.

23. The process of claim 20 wherein the inorganic halogen donor compound is selected from SnCl4, SbCl4, GeCl4 and POCl3.

24. The process of claim 23 wherein the molar ratio of the inorganic halogen donor compound to the vaporized metal is equal to or greater than 1.

25. The process of claim 14 wherein component (1) of the catalytic system is prepared by reacting the vaporized metal with the titanium compound in a M/Ti ratio equal to or greater than 4, M being metal.

26. The process of claim 25 wherein said M/Ti ratio is between 15 and 30.

27. A catalyst effective in the high-yield copoly-merization of ethylene or a mixture of ethylene and another .alpha.-olefin with a polyolefin selected from the group consisting of cyclic or alicyclic hydrocarbons containing more than one double bond, optionally conjugated, comprised of (1) a composition prepared by reacting a metal vapour with a titanium compound and a halogen donor, said metal vapour being selected from magnesium metal vapour and manganese metal vapour, and (2) an organoaluminium compound, wherein said magnesium metal is sublimed under a vacuum between 2 and 10-4 Torr and at a temperature between 300 and 650°C, and said manganese metal is sublimed under a vacuum between 10-1 and 10-4 Torr and at a temperature between 800 and 1100°C.

28. A catalyst as claimed in claim 27, wherein, said metal vapour is condensed into a diluent containing said titanium compound and optionally, said halogen donor.

29. A catalyst as claimed in claim 28, wherein said diluent is an inert solvent selected from the group consisting of aliphatic and aromatic hydrocarbons and said condensation is maintained at a temperature between -120°C and 0°C.

.30. A catalyst as claimed in claim 27, wherein in the catalytic system the titanium compound is selected from the halides, alcoholates, halogenoalcoholates and organometallic derivatives and trivalent and tetravalent titanium.

31. A catalyst as claimed in claim 27 wherein the halogen donor is selected from organic and inorganic halides.

32. A catalyst as claimed in claim 31 wherein the organic halogen donor compound is selected from chloroalkanes, bromoalkanes, chloroarenes and bromoarenes.

33. A catalyst as claimed in claim 32, wherein the molar ratio of the organic halogen donor compound to the vaporized metal is equal to or greater than 2.

34. A catalyst as claimed in claim 31 wherein the inorganic halogen donor compound is selected from SnC14, SbC14, GeC14 and POC13.

35. A catalyst as claimed in claim 34, wherein the molar ratio of the inorganic halogen donor compound to the vaporized metal is equal to or greater than 1.

36. A catalyst as claimed in, claim 27, wherein, component (1) of the catalytic system is prepared by reacting the vaporized metal with the titanium compound in a M/Ti ratio equal to or greater than 4, M being metal.

37. A catalyst as claimed in claim 36 wherein said M/Ti is between 15 and 30.

38. A catalyst effective in the high-yield copolyme-rization of ethylene or a mixture of ethylene and another .alpha.-olefin with a polyolefin selected from the group consisting of cyclic and alicyclic hydrocarbons containing more than one double bond, optionally conjugated, comprised of (1) a composition pre-pared by reacting a metal vapour with a titanium compound and a halogen donor, said metal vapour being selected from magnesium metal vapour and manganese metal vapour, and (2) an organo metallic compound of group III of the periodic table, wherein said magne-sium metal is sublimed under a vacuum between 2 and 10 Torr and at a temperature between 300 and 650°C, and said manganese metal is sublimed under a vacuum between 10-1 and 10-4 Torr and at a temperature between 800 and 1100°C.

39. In a process for the high-yield copolymerization of ethylene or a mixture of ethylene and another .alpha.olefin with a polyolefin selected from the group consisting of cyclic and ali-cyclic hydrocarbons containing more than one double bond optio-nally conjugated the improvement which comprises contacting said comonomers with a catalyst as claimed in claim 38.