MXPA96006464A - Catalysts for polymerization dealfa-olefi - Google Patents

Abstract

The present invention relates to a description of catalysts of the metallocene type, which can be used in the (co) polymerization of alpha-olefins, particularly in the preparation of ethylene elastomeric copolymers

Description

CATALYSTS FOR THE POLYMERIZATION OF ALPHA-OLEFINS DESCRIPTION OF THE INVENTION The present invention relates to new catalysts of the metallocene type and to the process for the production of (co) polymers of α-olefins, particularly elastomeric polymers of ethylene α-olefins, particularly ethylene-propylene, which utilizes these catalysts. The olefin-based elastomeric copolymers can be prepared by the polymerization of ethylene and an α-olefin, possibly in the presence of a diene. The most common elastomers based on olefins are elastomeric ethylene-propylene copolymers (EP elastomers) and ethylene, propylene, diene terpolymers (EPDM). For the above complex co-polymerizations of zirconium or titanium they are continuously being developed with bis-indenyl, bis-fluorenyl or mixed type ligands, such as fluorenylcyclopentadienyl ligands (PC Mohring, NJ Coville, J. Organgan, Chem. 479, 1, 1994). However, these catalysts have the disadvantage that they do not always produce copolymers with an acceptable viscosity from an application point of view, particularly in the preparation of elastomeric ethylene-propylene copolymers with propylene content of between 40 and 65% by weight, a range of the composition which gives the best results in terms of elastomeric properties. It is also known that in the preparation of EP or EPDM copolymers the copolymerization is often carried out in the presence of hydrogen as a molecular weight regulator. The use of hydrogen, however, sometimes creates considerable difficulties due to the high sensitivity for the hydrogen of the metallocene-based catalytic system. As a result, the amounts of hydrogen suitable for regulating the molecular weight are too small to be conveniently distributed. Now new zirconium complexes have been found which overcome the above disadvantages. The above catalysts are also active in the (co) polymerization of α-olefins. Accordingly, the present invention relates to a catalytic component for the (co) polymerization of α-olefins characterized in that it comprises one or more compounds containing the general formula (I) wherein "X" is selected from halogen, hydride, hydrocarbyl radical, alkoxide, dialkylamide, preferably halogen, hydride, hydrocarbyl radical; even more preferred is chlorine; "n" is an integer between 2 and 18 and preferably is selected from 3, 5, 6, 10; R and R * are selected from H, alkyl radicals having from 1 to 5 carbon atoms, cycloalkyl radicals having from 5 to 8 carbon atoms, aryl radical and alkylaryl having from 6 to 8 carbon atoms, aralkyl radicals which they have 7 to 9 carbon atoms, "M" is zirconium, with the proviso that referring to general formula (II), - the number of R different from H is not greater than 2; - at least one of two R * is H, preferably the two R * are selected from H and the alkyl radical from Cl-C3; excluding the compound having n = 4, R = R * = R * = H. The compounds having the general formula (I) can be prepared from cyclopentadienyl derivatives, having the general formula (II) described in the copending patent application filed by the same applicant IT-A-M195 02707.

(D) With respect to the meanings of R and R *, typical examples of C ^ to C5 alkyl radicals are methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl , iso-pentyl, neo-pentyl. Typical examples of cycloalkyl radicals having from 5 to 8 carbon atoms are cyclopentyl, cyclohexyl, methylcyclopentyl, methylcyclohexyl.

Typical examples of aryl and alkylaryl radicals having 6 to 8 carbon atoms are phenyl, methylphenyl, ethylphenyl, dimethylphenyl. A preferred form of the R and R * modality are selected from H and alkyl radicals from C ^ to C-j. In yet a more preferred form of the modality, n is selected from 3, 5, 6, 10, R is H, R * is selected from H and alkyl radicals from C1 to C3. Non-limiting examples of the compounds having the general formula (I) are: (1) bis- (4,5,5,6-trihydro-pentalenyl) zirconium dichloride; (2) bis- (1-methyl-4,5,6-trihydro-pentalenyl) zirconium dichloride; (3) bis- (4-methyl-, 5,6- trihydro-pentalenyl) zirconium dichloride; (4) bis- (1,4-methyl-4,5,6-trihydro-pentalenyl) zirconium dichloride; (5) bis- (5-methyl-4,5,6,6-trihydro-pentalenyl) zirconium dichloride; (6) bis- (1,5-dimethyl-4,5,6-trihydro-pentalenyl) zirconium dichloride; (7) bis- (5-phenyl-4,5,6,7-tetrahydro-indenyl) zirconium dichloride; (8) bis- (4, 5, 6, 7, 8-pentahydro-azulenyl) zirconium dichloride; (9) bis- (1-methyl-4, 5, 6, 7, 8-pentahydro-azulenyl) zirconium dichloride; (10) bis- (4, 5, 6, 7, 8, 9-hexahydro-cyclopentacyclooctenyl) zirconium dichloride; (11) bis- (1-methyl-4, 5, 6, 7, 8, 9-hexahydro-cyclopentacyclooctenyl) zirconium dichloride; (12) Bis- (4, 5, 6, 7, 8, 9, 10, 11-octahydro-cyclopentacyclodecenyl) zirconium dichloride; (13) bis- (1-methyl-4, 5, 6, 7, 8, 9, 10, 11-octahydro-cyclopentacyclodecenyl) zirconium dichloride; (14) bis- (4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium dichloride; (15) bis- (1-methyl-4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium dichloride; (16) bis- (5,6-diphenyl-4,5,6,7-tetrahydro-indenyl) zirconium dichloride; (17) bis- (1-phenyl-4, 5, 6, 7, 8-pentahydro-azulenyl) zirconium dichloride; (18) bis- (1-phenyl-4, 5, 6, 7, 8, 9-hexahydro-cyclopentacyclooctenyl) zirconium dichloride; (19) bis- (1-phenyl-4, 5, 6,7, 8, 9, 10, 11, 12, 13 -decahydro-cyclopentacyclododecenyl) zirconium dichloride; Other examples are those in which, again with reference to compounds 1 to 19, the chlorides are substituted with methyls, phenyls, methoxides, phenoxides. A typical example, which is illustrative but not limiting, for the preparation of the compounds having the general formula (I) is to react the compound with the general formula (II), which will shortly be called HRb, with ZrCl4 according to the following scheme: HRb + n-C4H9L: L-- > RbLi + n- C4H1Q 2RbLi + ZrCl4 - > (Rb) 2ZrCl2 + 2LIC1 Another object of the present invention relates to a process for the homo and copolymerization of C2-C20 α-olefins, particularly C2-C1Q α-olefins, which utilizes a catalyst system comprising the compound that has the general formula (I). In the (co) polymerization of the α-olefins, the catalyst system also comprises, in addition to the metallocene having the general formula (I), another component (which will be called co-catalyst) selected from alumoxane and compounds having the formula general (III) (Ra)? NH4_? B (Rd) 4, or (IV) (RA) 3PHB (Rd) 4, or (V) B (Rd) 3, which by reaction with a metallocene having the General formula (I) are capable of generating ionic catalytic systems. In the above compounds having the general formula (III), (IV) or (V), the Ra groups, the same or different, are monofunctional alkyl or aryl radicals, while the same or different Rd are monofunctional aryl radicals, preferably partially or fully fluorinated, even more preferably fully fluorinated. When the compounds having the general formula (III), (IV) or (V) are used as the co-catalysts, the catalytic system will basically consist of the products of the reaction of one or more metallocenes having the general formula (I ), wherein X is equal to H or a hydrocarbyl radical with any of the compounds having the general formula (III), (IV) or (V), or a mixture thereof, as described in EP- A-277, 004, the molar ratio between the compound having the general formula (III), (IV) or (V), and the metallocene having the general formula (I) which is between 0.1 and 10, preferably between 0.5 and 3, still more preferably between 0.7 and 2. When X is different from H or the hydrocarbyl radical, the catalytic system consists of one or more metallocenes having the general formula (I), an alkylating compound (VI) selected from trialkylaluminum, dialkylmagnesium or alkyl lithium or other alkylating agents well known to those skilled in the art and any of the compounds having the general formula (III), (IV) or (V) or a mixture thereof, as described in EP-A-612769. The method of forming the catalytic system involves pre-mixing the metallocene compound having the general formula (I) with a suitable alkylating agent (VI) in aliphatic or aromatic hydrocarbon solvents, or mixtures thereof, at a temperature between -20 ° to + 100 ° C, preferably between 0 ° C and 60 ° C and more preferably between + 20 ° C and + 50 ° C for a time ranging from 1 minute to 24 hours, preferably from 2 minutes to 12 hours hours, even more preferred from 5 minutes to 2 hours. The mixture is then contacted with a compound having the general formula (III), (IV) or (V), at the above temperature for a time between 1 minute and 2 hours, preferably between 2 minutes and 30 minutes and is subsequently fed into the polymerization reactor. The molar ratio between the alkylating compound (VI) and the compound having the general formula (I) can vary from 1 to 1000, preferably from 10 to 500, even more preferably from 30 to 300. The molar ratio between the compound having the general formula (III), (IV) or (V) and the metallocene (I) can vary from 0.1 to 10, preferably from 0.5 to 3, even more preferably from 0.7 to 2. With respect to the alumoxane, this is a compound of aluminum which, in its linear form, has the general formula (VII) (Re) 2-Al-0 - [- Al (Re) -0-] p-Al (Re) 2 (VII), while in cyclic form having the general formula (VIII) - [- 0-Al (Re) -] p + 2 - wherein Re, similar or different, is selected from C 1 - Cg alkyl radicals, Cg-C 18 aryl radicals or H, "p" is an integer between 2 and 50, preferably between 10 and 35. The various Re are preferably equal to each other and are selected from methyl, isobutyl, phenyl or benzyl, preferably methyl. When the various Re's are different, preferably methyl and hydrogen or alternatively methyl and isobutyl, the hydrogen or isobutyl preferably is present, as the number of radicals Re, is between 0.1 and 40% by weight. The alumoxane can be prepared according to various methods known to those skilled in the art. One of the methods, for example, comprises the reaction of an aluminum-hydrocarbon compound and / or a hydroaluminium-aluminum with water (gaseous, solid, liquid or bound, for example, as water of crystallization) in an inert solvent, example, toluene. For the preparation of an alumoxane having different alkyl groups of Re, two different trialkyls aluminum (AlR3 + AlR'3), are reacted with water (see S. Pasynkie icz, Polyhedron 9 (1990) 429-430 and the EP- A-302 424). The exact structure of alumoxane is not known. It is possible to pre-activate the metallocene with the alumoxane before its use in the polymerization phase. This considerably increases the polymerization activity and improves the morphology of the particles. The above pre-activation is preferably carried out in a solvent, dissolving the metallocene in a solution of an inert hydrocarbon, preferably aliphatic or aromatic, even more preferably in toluene. The concentration of the alumoxane in the solution is in the range of 1% by weight up to the saturation value, preferably from 5 to 30% by weight with respect to the total weight of the solution. The metallocene can be used in the same concentration, but is preferably used in an amount of between 10-4 and 1 mol per mol of alumoxane. The pre-activation time is between 5 minutes and 60 hours, preferably between 5 and 60 minutes. The temperature is between -78 ° C and 100 ° C, preferably between 0 ° C and 70 ° C. The catalyst system of the present invention (catalyst having the general formula (I) and co-catalyst) can be prepared by placing the catalyst in contact with the co-catalyst in the presence of or without the monomer to be polymerized, within or outside the reaction reactor. The amounts of the catalyst and the co-catalyst are not particularly limited. For example, in the case of polymerization in a solvent, the amount of the catalyst is preferably in the range of 10 ~ 7 and 10 ~ 2 moles / liter, still more preferably 10-4 to 1 mmol / liter in terms of of the transition metal M. When the alumoxane is used, the molar ratio between the aluminum and the transition metal M is preferably greater than 10 and less than 10 000. As well as the catalyst and the co-catalyst, the catalytic system it may contain an optional third component, usually one or more substances having active hydrogen atoms, such as water, alkanols (for example methanol, ethanol, butanol), or electron donating compounds, such as ethers, steres, amines, compounds which they contain alkoxide groups such as phenyl borates, dimethylmethoxyaluminium, phenylphosphate, tetraethoxysilane, diphenyldimethoxysilane. The catalyst and co-catalyst can be introduced separately into the reaction reactor or after being previously in contact with each other. In the latter case, the contact can be carried out in the presence of a monomer, which will then be polymerized, thus effecting the so-called "preliminary polymerization". To return to the copolymerization process, it is convenient to eliminate catalyst poisons, which are possibly present in the monomers, particularly in propylene. In this case, the purification can be carried out with an alkylaluminum, for example AlMe, AlEt3, Al (iso-Bu) 3. This purification can be carried out in the polymerization system or alternatively, before the polymerization by placing the propylene in contact with the aluminum alkyl and subsequently separating it. The catalyst system of the present invention can be applied to the polymerization in the suspension phase (where a dispersant, for example propane or butane) is used, so that the polymerization is carried out basically without a solvent (such as polymerization). without a solvent in a liquid phase and polymerization in a gas phase), and solution polymerization. The catalyst of the invention can obviously be applied to the polymerization in continuous or discontinuous form. When the polymerization is carried out in a solvent, the aliphatic and aromatic hydrocarbons can conveniently be used as diluents, either alone or mixed together.

The catalytic component having the general formula (I) can be supported on inert carriers. Suitable techniques for supporting metallocene components on porous solids, for example silica and alumina, possibly in the presence of the co-catalyst, are well known in the literature. The catalyst system supported in this form can be used as such or pre-polymerized with α-olefin monomers. The support allows the heterogeneous catalytic components to be obtained with a specific morphology and particle size, particularly suitable for the gas phase polymerization processes. The polymerization temperature is in the range of -78 ° C to 200 ° C, preferably -20 ° to 100 ° C. There are no particular limitations on the pressure of the olefin in the reaction system, even if the pressure is preferably within the range of atmospheric pressure at 50kg / cm2 G. In the polymerization process, the molecular weight can be controlled with any known method, for example by the appropriate selection of polymerization temperature and pressure or by the introduction of hydrogen. The olefins that can be polymerized with the process of the present invention are alpha-olefins (comprising ethylene) having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms. Typical examples of alpha-olefins which can be (co) polymerized with the process of the present invention are ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1 -dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene. Another object of the present invention relates to a process for the preparation of elastomeric ethylene / α-olefin copolymers or ethylene / α-olefin / elastomeric diene terpolymers, preferably ethylene-propylene (EPM) or ethylene-propylene-diene (EPDM) with a propylene content of between 15 and 75% by weight, preferably between 25 and 70% by weight, even more preferred between 40 and 60% by weight, which comprises the following steps: 1) a The olefin and the possible diene is fed into the polymerization reactor, preferably diluted with C3-C5 low-boiling hydrocarbon, preferably propane, at a pressure such as to allow the use of this α-olefin in a liquefied; 2) ethylene is added to the mixture obtained in step (1) in an amount which is sufficient to maintain the desired ethylene / olefin ratio in the liquid phase; 3) the catalyst system is added, comprising one or more metallocenes and one or more co-catalysts selected from alumoxane and compounds having the general formula (III) (Ra)? NH4_? B (Rd) 4 or having the formula general (IV) (Ra) 3PHB (Fd) 4 or general formula (V) B (Rd) 3, possibly in the presence of an alkylating compound (VI); 4) the mixture obtained in step (3) is reacted for a time, which is sufficient to allow the polymerization of the ethylene-α-olefin and the possible diene system to give an EP (D) M having a Mooney viscosity (ML1 + 4 at 100 ° C) greater than 25, characterized in that the catalyst system comprises a metallocene selected from those having the general formula (I) (D wherein each "X" is independently selected from halogen, hydride, hydrocarbyl radical, alkoxide, dialkylated ida and is preferably selected from halogen, hydride, hydrocarbyl radical; "n" is an integer between 2 and 18 and is preferably selected from 3, 4, 5, 6, 10; R and R * are selected from H, alkyl radicals having from 1 to 5 carbon atoms, cycloalkyl radicals having from 5 to 8 carbon atoms, aryl and alkylaryl radicals having from 6 to 8 carbon atoms, aralkyl radicals which have from 7 to 9 carbon atoms, "M" is zirconium, with the proviso that with reference to the general formula (II), - the number of R different from H is not greater than 2; - at least one of two R * is H, preferably the two R * are selected from H and CH3; excluding the compound having n = 4, R = R * = H. In a preferred form of the embodiment, R and R * are selected from H and from alkyl radicals of C- ^ to C. In an even more preferred form of the embodiment, n is selected from 3, 5, 6, 10, R is H, R * is selected from H and alkyl radicals from C- ^ to C3. The α-olefins, which can be used in the production of copolymers with ethylene are those described in the above. Typical examples of the dienes which can be used for the preparation of EPDM are 5-ethylidene-2-norbornene (ENB), 1,4-hexadiene, dicyclopentadiene; the diene is preferably 5-ethylidene-2-norbornene.

When preparing EPDM, the diene content in the polymer is less than 15% by weight, preferably 2 to 10%, the propylene content is that specified in the above. The process for the production of EP (D) M is carried out by the polymerization in a suspension phase of ethylene, α-olefin, preferably propylene, and the possible diene, optionally diluted with a hydrocarbon of C3 to Cede under point of boiling, preferably propane. A catalyst system is suspended in this mixture, which consists of the metallocene having the general formula (I) and the co-catalyst selected from MAO and the compounds having the general formula (III), (IV) and (V) and optionally the alkylation compound (VI). This catalyst system is present in such an amount as to provide a sufficient amount of polymer containing the optional diene. The concentration of the optional diene in the reactor, as a percentage by volume, is between 0.05 and 10%, preferably between 0.2 and 4%. The ethylene is fed to the reactor at a pressure higher than the pressure inside the reactor. The ethylene content of the polymer is determined from the ratio between the partial ethylene pressure and the total pressure in the polymerization reactor. This partial ethylene pressure is generally maintained at between 0.5 and 50 bar, more preferably between 1 and 15 bar. The temperature of the reactor is maintained between -10 ° and 90 ° C, more preferably between 20 ° and 60 ° C. Under these operating conditions, ethylene, α-olefin and optional diene are polymerized to give an EP (D) M elastomer. The polymerization can be carried out with a discontinuous process in suspension or preferably in a continuous process with a constant feed of the mixture of monomers, possibly diluted with low boiling hydrocarbon and the catalyst system. Without limitations for the scope of the present invention, a process for carrying out the process of the present invention is as follows: The liquid propylene is fed continuously into a stirred reactor together with the ethylene and optional diene, possibly diluted with low boiling C3-C5 hydrocarbon. The reactor contains a liquid phase consisting basically of liquid propylene, optional diene monomers, the low-boiling hydrocarbon, optionally together with the gaseous ethylene dissolved therein and a gas phase containing vapors of all the components. The fed ethylene is introduced either as a gas in the vapor phase or as a liquid phase, as is known to those skilled in the art.

The components of the catalytic system (catalyst, co-catalyst, the optional alkylation compound and an optional scavenger or sequestrant) can be introduced into the reactor, by means of additional valves either in gas or liquid phase, preferably in liquid phase . The polymerization is carried out in the liquid phase generating an insoluble copolymer in the same phase, with a residence time of the suspension in the reactor, which varies from 10 minutes to 10 hours and preferably from 30 minutes to 2 hours; longer residence times produce final polymers with a lower content of catalytic residues. The temperature of the reactor can be controlled by cooling the reactor by means of a coil or liner in which the cooling liquid circulates or, more preferably, by evaporation and condensation of the α-olefin (and the optional low-boiling hydrocarbon) and fed back into the reactor. The polymer thus produced is recovered by subjecting it to a washing treatment with water in a vapor stream to remove the unconverted monomers and the optional diluent, and effecting a treatment in the extruder to remove water and horizontal residual traces of α-olefins.

The following Examples provide a better understanding of the present invention.

Example 1 Synthesis of bis- (4) dichloride, 5, 6, 7, 8-pentahydro-azulenyl) zirconium, (compound having the formula (I) wherein n = 5, R = R * = H, X = C1). An ethereal solution of 2.8 g (0.02 moles) of 2,4,5,6,7,8-hexahydroazulene is prepared, the preparation described in Example 1 of the co-pending patent application filed by the same applicant. 12.5 mi are added. from a solution of 1.6 M LiMe to the above solution: the methane is released with the subsequent precipitation of a white solid. The mixture is left under stirring overnight, then cooled to -70 ° C and 2.4 g (0.01 mol) of solid ZrCl4 are added. The temperature is allowed to increase to room temperature (approximately 20 ° C), the stirring is maintained for 4 hours and the mixture is filtered. The residue is washed with ethyl ether and then extracted with methylene chloride (2 x 75 ml.). The extract is concentrated and the solid thus obtained is filtered, washed with pentane and dried. 1.4 grams of the product are obtained (33% yield). The zirconium complex then prepared has the following NMR spectrum: 1H-NMR (CDC13, ppm TMS re): 5.99 (m, 6H); 2.65 (m, 8H); 1.91 (m, 6H); 1.55 (m, 2H); 1.25 (m, 4H). 13 C-NMR (CDCl-j, ppm, TMS): 29.06; 31.23; 32.86; 107.47; 115.9; 135.78.

Example 2 Synthesis of bis- (4, 5, 6, 7, 8, 9-hexahydrocyclopentacyclooctenyl) zirconium dichloride, (compound having the formula I wherein n = 6, R = R * = R * = H, X = C1). An ethereal solution of 3.1 g is prepared (0.021 moles) of 4, 5, 6, 7, 8, 9-hexahydro-2H-cyclopentacyclooctene, the preparation of which is described in the co-pending patent application filed by the same applicant. 8.5 mi are added. of a solution of 2.5 M of butyl lithium in hexane to the above ether solution obtaining a white precipitate. The mixture is left stirring for 4 hours and then cooled to -70 ° C and then 2.5 g (0.011 mole) of solid ZrCl4 is added. The temperature is allowed to increase to room temperature (approximately 20 ° -25 ° C). The mixture is filtered, washed with ethyl ether and then extracted with methylene chloride. In the concentration, a voluminous solid precipitates, which is filtered and washed carefully, due to its high solubility, with methylene chloride and then with hexane. 0.4 g of the product was obtained. In the concentration of the mother liquor the solid is obtained again which, after filtering and washing, again provides 0.6 g of the pure product. In this way, 1.0 g of the pure complex (20% yield) are obtained. The zirconium complex then prepared has the following NMR spectrum: XH-NMR (CDC13, ppm, TMS): 6.15 (t, 2H); 6.02 (d, 4H); 2.60 (m, 8H); 1.40 (m, 16H). 13 C-NMR (CDC13, ppm, TMS): 26.5; 27.9; 32.57; 109.1; 114.6; 134.0.

Example 2A Synthesis of bis- dichloride (4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium, (compound having the formula I wherein n = 10, R = R * = R * = H, X = C1). Add 12.5 ml of a 1.6 M solution of LiMe at room temperature to an ethereal solution of 4.1 g (0.02 moles) of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-2H -cyclopentacyclododecene (the preparation of which was described in Example 3 of the co-pending patent application filed by the same applicant and has a purity of 81%). Gas is evolved and soon after a white solid precipitates. The mixture is left stirring overnight. Cool to -70 ° C and add 2.4 g (0.01 moles) of ZrCl4. The temperature is allowed to rise to room temperature and the mixture is allowed to stir for 4 hours. It is filtered, washed with ethyl ether and extracted with methylene chloride (2x75ml). The extract is concentrated, filtered and the solid is washed with pentane and dried under vacuum. 1.6 g (yield 28%) of the product are obtained, which are pure in the NMR analysis. It should be noted that at the end of this process, the impurity initially present in the initial ligand is almost completely absent. NMR spectrum: -H-NMR (CDC1-, ppm, TMS): 6.15 (s, 6H); 2.65 (ddd, 4H); 2.35 (ddd, 4H); 1.85-1.5 (m, 16H); 1.5-1.1 (m, 16H). 13 C-NMR (CDC 13, ppm, TMS): 23.57; 25.81; 25.95; 26. 43; 30.37; 108.36; 115.32; 134.06.

Example 2B Synthesis of bis- (1-methyl-4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium dichloride, (compound having the formula I wherein, referring to the General Formula (II), n = 10, R = R * = H, R * = CH3 X = C1). 7 grams (0.032 moles) of 1-methyl-4,5,6,7,8, 9,10,11,12,13-dehydro-2H-cyclopentacyclododecene (the preparation of which was described in Example 4 of the patent application copendiente presented by the same applicant and having a purity of 75%) are dissolved in the pentane and the previous solution is then treated with 15 ml of BuLi in hexane. By the addition of THF samples an abundant precipitate is formed immediately which, after filtration, washing with pentane and drying gives 4.3 g of the lithium salt (4.3 g, 0.019 mol). 2.4 g (0.01 mol) of ZrCl4 are added to the lithium salt, suspended in ethyl ether and maintained at -70 ° C. The temperature is allowed to rise to room temperature: a viscous suspension is formed which is difficult to stir. After 2 hours at room temperatureThe suspension is filtered, washed again with ether and extracted with 500 ml of methylene chloride under light heating. The mixture is concentrated in small volumes (50 ml), cooled to -20 ° C and filtered. It is washed with cold methylene chloride and then dried to obtain 3.5 g of the product. By recrystallization from methylene chloride, 1.5 g of the product are obtained whose characteristics are identical to those of the non-crystallized product (84% of total yield). It should be noted that, also in this case, at the end of the process the impurity present in the initial ligand is almost completely absent.

NMR spectrum: iH-NMR (CDCl-;, ppm, TMS): 5.92 (d, 2H); 5.78 (d, 2H); 2.55 (m, 6H); 2.1 (m, 8H); 1.8-1.1 (m, 32H). 13 C-NMR (CDC13, ppm, TMS): 15.73; 23.14; 23.84 24.47, 25.91; 25.93; 26.82; 26.97; 27.23; 27.27; 27.96 30.36; 108.53; 109.40; 109.49; 129.76; 130.08; 131.41 134.53; 134.79. Examples 3-9 and Comparative Examples Cl and C2 Synthesis of ethylene-propylene copolymers and propylene-ethylene-diene terpolymers. The polymerizations are carried out in a 3.3 liter pressure-resistant reactor, regulated with thermostat and equipped with a magnetic drag anchor stirrer, according to the following procedure: After flooding the reactor with propylene containing tri-isobutyl 5% aluminum by weight / volume and washing with freshly prepared propylene, 2 liters of propylene "Polymerization degree" liquid and optionally the third monomer (ENB) are fed at 23 ° C. The pressure-resistant reactor is then brought to the pre-set temperature for the polymerization (precisely 45 ° C for tests 1 and Cl and 40 ° C for the other tests) and a 10% hexane solution of TIBA (tri -isobutyl aluminum) corresponding to 1.5 mmole of Al. Subsequently, optional gaseous hydrogen and ethylene are added by means of a plugged tube at the preset ratios to achieve the desired partial pressures. The catalyst is prepared as follows: A solution of the metallocene in 10 ml of anhydrous toluene is prepared in a Schlenk tube maintained in a nitrogen atmosphere, to which is added a solution of methylalumoxane (MAO) at 30% in toluene (product WITCO commercial called Eurocen Al 5100 / 30T) in the amount needed to obtain the desired ratio of Al / Zr. The resulting solution is emptied into a steel cylinder maintained under a nitrogen atmosphere and rapidly introduced into the pressure-resistant reactor with a nitrogen overpressure. The reactor pressure is kept constant by feeding ethylene from a cylinder controlled in weight. After 1 hour, the ethylene feed is discontinued, the residual monomers are degassed and the pressure resistant reactor is cooled to room temperature. The polymer is discharged and homogenized with a roller mixer and finally characterized.

Physical-Chemical Analysis and Characterizations The following measurements are carried out on the polymers obtained in this way: - Propylene content and ENB content: The determination is carried out by IR in the polymers in the form of films with a thickness of 0.2 mm, using a Perkin-Elmer model 1760 FTIR spectrophotometer.

- Intrinsic Viscosity: The measurements are carried out at 135 ° C with the polymer dissolved in orthodichlorobenzene. The drip times of the solvent and solutions with increasing concentrations in the polymer under examination, are measured using an Ubbelhode-type viscometer. The extrapolation of the reduced viscosity that is related to the zero concentration gives the value of the intrinsic viscosity.

- Molecular weight distribution: The analysis is carried out with the gel permeation chromatography technique in orthochlorobenzene at 135 ° C using a Waters ALC / GPC 135 instrument. The calibration curve used to calculate the molecular weight is obtained with samples standard of monodispersed polyethylene, by the Mark-Houwink equation valid for linear polyethylene and polypropylene. The molecular weights are correlated in relation to the composition, by means of the Sholte equation (J.Appl., Poly. Sci. 1984, 29, pages 3363-3782).

- Mooney Viscosity: (l 4) This is determined at 100 ° C using a "1500 S" viscometer from Monsanto, in accordance with ASTM D 1646/68.

- Vulcanization The mixtures that are going to be vulcanized are prepared using the formulations used in Table 1.

TABLE 1 Ingredients Parts by weight for EPM for EPDM Polymer 100 100 FEF (1) carbon black 55 55 Zinc oxide 5 5 Peroxy on F40 MG (2) 5 5 Sulfur 0. . 37 1. 5 Tetramethylthiurandisulfide 1. 5 Mercaptobenzothiazole 0. 75 Paraffin oil (3) 30 30 (1) High Abrasion Furnace, little carbon black structure of cabot; (2) bis (tert-butylperoxy-isopropyl) -benzene, masterbatch at 40% in the EP copolymer, produced by Atochem.

- Mechanical Characterization The mechanical characteristics of the vulcanized copolymers were measured according to the ASTM methods indicated in Table 2, using samples taken from the molded plates in a plate press at 165 ° C for 40 minutes and at 18 MPa.

TABLE 2 CHARACTERISTICS METHOD Resistance to breakage D 412-68 Elongation to breaking D 412-68 Voltage adjusted to 200% D 412-68 Hardness Shore A D-2240-68 EXAMPLES Cl Y C2 Comparative Examples Cl and C2 refer to the copolymerization of ethylene with propylene with bis (tetrahydroindenyl) zirconium dichloride in the presence of MAO and without a molecular weight regulator. Table 3 indicates the polymerization conditions and the main characteristics of the copolymers thus obtained, using the metallocenes of the present invention, compared to two polymers (Cl and C2) obtained using bis (tetrahydroindenyl) zirconium dichloride of the prior art. Table 4 indicates the main mechanical characteristics after vulcanization of the obtained copolymers. A comparison of Comparative Examples Cl and C2 shown as, in the case of the production of the EP copolymers with a propylene content of more than 40% by weight, the Mooney viscosities of the polymers obtained with the catalysts of the present invention, they are decidedly greater than the corresponding viscosities of the copolymers prepared with the catalysts of the prior art. EP copolymers prepared with the catalysts of the present invention are elastomeric as can be seen from the physico-mechanical characterizations of Table 4 and in particular from the established voltage values which remain low. The established value of the tension of less than 25% of the vulcanized product of Example 6 with high ethylene content should be noted. Example 5 shows that the same catalyst system of Examples 3 and 4 allows the use of hydrogen as a molecular weight regulator; this is without an excessive loss of catalytic activity obtaining a copolymer having an average level of Mooney viscosity. Example 9 shows that the catalysts of the present invention, in the presence of hydrogen, allow the chaining of the ENB monomer producing an EPDM terpolymer having an average molecular weight with good elastic properties (see Table 4). Examples 7 to 9 show as another catalyst of the present invention, it has similar behavior in the polymerization of that of Examples 3 to 6. In Table 3, complex "A" is the catalyst of bis (tetrahydroindenyl) zirconium dichloride. of the prior art. The complex (1) of Table 3 is the metallocene of Example 1 and the complex (2) of Table 3 is the metallocene of Example 2. In the same Table, the yield is expressed in Kg pol./gZr.h.

TABLE 3 TABLE 4 In conclusion, the data in Tables 3 and 4 only show how the catalysts of the present invention are effective in the preparation of ethylene-propylene copolymers having a propylene content of more than 40%. Also EP copolymers with a propylene content of less than 40% can be prepared efficiently with the catalysts of the present invention.

EXAMPLE 10 An ethylene-propylene copolymer was prepared using a catalyst prepared as follows: a solution with 2 ml. of toluene, 0.3 g of the metallocene of Example 2 and a hexane solution of 10% TIBA is prepared in a 100 ml glass test tube, filled with nitrogen, in such a way that the molar ratio of Al / Zr is equal to 300. The solution is heated for 1 hour at 40 ° C under stirring, then diluted with 8 ml. of toluene and a 0.2% solution in toluene of the tetra (per-fluorophenyl) borate of N, N-dimethylaniline is added, in such a way that the molar ratio of B / Zr is equal to 2. The liquid obtained is then fed immediately. to the pressure resistant reactor for the copolymerization test without MAO. At the end of the polymerization, an EPM with a propylene content of 38% by weight and ML Mooney (1 + 4, 100 ° C) of 32, is discharged into the reactor. The polymerization yield was equal to 2535 Kg per gram of zirconium per hour. This example shows that the catalysts of the invention provide ethylene-propylene copolymers with high productivity using, as an alternative co-catalyst for MAO, an activator capable of generating an ion pair by reaction with the metallocene having the formula (I)

Claims (24)

1. A catalytic component for the copolymerization of alpha-olefins characterized in that it comprises a compound having the General Formula (I) (D wherein "X" is selected from halogen, hydride, hydrocarbyl radical, alkoxide, dialkylamide; "n" is an integer between 2 and 18; R and R * are selected from H, alkyl radicals having from 1 to 5 carbon atoms, cycloalkyl radicals having from 5 to 8 carbon atoms, aryl and alkylaryl radicals having from 6 to 8 carbon atoms, aralkyl radicals which have from 7 to 9 carbon atoms, "M" is zirconium, with the proviso that, with reference to the General Formula (II), - the number of R different from H is not greater than 2; - at least 1 of two R * is H; excluding the compound having n = 4, R = R * = R * = H.

2. The catalyst component according to claim 1, characterized in that n is selected from 3,5,6,10.

3. The catalyst component according to claim 1, characterized in that X is selected from halogen, hydride, hydrocarbyl radical.

4. The catalyst component according to claim 3, characterized in that the halogen is chlorine.

5. The catalytic component according to claim 1, characterized in that R * is selected from H radicals and C1-C3 alkyl.

6. The catalytic component according to claim 2, characterized in that R * is H, R * is selected from H radicals and C- to C3 alkyl.

7. Bis- (4, 5, 6, 7, 8-pentahydro-azulenyl) zirconium dichloride, according to claim 1.

8. Bis- (4, 5, 6, 7, 8, 9-hexahydro-cyclopentacyclooctenyl) zirconium dichloride, according to claim 1.

9. Bis- (4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium dichloride, according to claim 1.

10. Bis- (1-methyl-4, 5, 6, 7, 8, 9, 10, 11, 12, 13-decahydro-cyclopentacyclododecenyl) zirconium dichloride, according to claim 1.

11. A process for the homo and copolymerization of C2-C20 alpha-olefins, particularly alpha-olefins of C -C \ Q > characterized in that it is carried out in the presence of a catalyst system, which comprises a compound having the General Formula (I) (D wherein "X" is selected from halogen, hydride, hydrocarbyl radical, alcdxide, dialkylamide, "n" is an integer between 2 and 18, R and R * are selected from H, alkyl radicals having from 1 to 5 carbon atoms, cycloalkyl radicals having from 5 to 8 carbon atoms, aryl and alkylaryl radicals having from 6 to 8 carbon atoms, aralkyl radicals having from 7 to 9 carbon atoms, "M" is zirconium, with the condition that, with reference to the General Formula (II), - the number of R different from H is not greater than 2, - at least 1 of two R * is H, excluding the compound having n = 4, R = R * = R * = H.

12. The process according to claim 11, characterized in that n is selected from 3,5,6,10.

13. The process according to claim 12, characterized in that R is H, R * is selected from the radicals H and C1-C3 alkyl.

14. The process according to claim 11, characterized in that X is selected from halogen, hydride, hydrocarbyl radical.

15. The process according to claim 14, characterized in that X is halogen.

16. The process for the preparation of elastomeric ethylene α-olefin copolymers or ethylene / α-olefin / elastomer diene terpolymers, preferably ethylene-propylene (EPM) or ethylene-propylene-diene (EPDM) with a propylene content of between 15 and 75% by weight, which comprises the following steps: 1) an α-olefin and the optional diene is fed into the polymerization reactor, preferably diluted with low-boiling hydrocarbon of preferably c3 ~ c5 propane, at a pressure such as to allow the use of this α-olefin in a liquefied form; 2) ethylene is added to the mixture obtained in step (1) in an amount which is sufficient to maintain the desired ethylene / olefin ratio in the liquid phase; 3) the catalyst system is added, comprising one or more metallocenes and one or more co-catalysts selected from alumoxane and compounds having the general formula (III) (Ra)? NK4_? B (Rd) 4 or having the general formula (IV) (Ra) 3PHB (Rd) 4 or general formula (V) B (Rd) 3, possibly in the presence of an alkylating compound (VI); 4) the mixture obtained in step (3) is reacted for a time, which is sufficient to allow the polymerization of the ethylene-α-olefin and the optional diene system to give an EP (D) M having a Mooney viscosity (ML1 + 4 at 100 ° C) greater than 25, characterized in that the catalytic system comprises a metallocene selected from those having the general formula (I) wherein each "X" is selected from halogen, hydride, hydrocarbyl radical, alkoxide, dialkylamide; n is an integer between 2 and 18; R and R * are selected from H, alkyl radicals having from 1 to 5 carbon atoms, cycloalkyl radicals having from 5 to 8 carbon atoms, aryl and alkylaryl radicals having from 6 to 8 carbon atoms, aralkyl radicals which have from 7 to 9 carbon atoms, "M" is zirconium, with the proviso that with reference to the general formula (II), - the number of R different from H is not greater than 2; - at least one of two R * is H; -excluding the compound that has n = 4, R = R * = R * = H.

17. The process in accordance with the claim 16, characterized in that ethylene-propylene (EP) or ethylene-propylene-diene (EPDM) copolymers are produced with a propylene content of between 25 and 70% by weight.

18. The process in accordance with the claim 17, characterized in that the propylene content is between 40 and 60% by weight.

19. The process for the preparation of ethylene-propylene-elastomeric diene terpolymers (EPDM) according to claim 16, characterized in that the diene content is less than 15% by weight.

20. The process in accordance with the claim 19, characterized in that the diene content is between 2 and 10%.

21. The process according to claim 16, characterized in that n is selected from 3,4,5,6,10.

22. The process according to claim 16, characterized in that X is selected from halogen, hydride, hydrocarbyl radical.

23. The process according to claim 22, characterized in that X is halogen.

24. The process according to claim 21, characterized in that reference is made to the General Formula (II), R = H and R * are selected from the radicals H and C 1 -C 3 alkyl.