MXPA97010321A - Metalocenos, its preparation and use in the polymerization of alfa-olefi - Google Patents

Abstract

The present invention relates to a catalytic component for the copolymerization of ethylene with alpha-olefins having the general formula (I) (see formula) in which: A is a cyclopentadienyl derivative having the general formula (II) (see formula ) B is selected from: 1) any of the cyclopentadienyl derivatives A defined in the above 2) a monofunctional cyclopentadienyl radical (F) selected from cloclopentadienyl, indenyl, fluorenyl and relative of the alkyl, aryl, substituted-alkyl-alkylsilyl derivatives; bridge between A and B, is a radical bifunction

Description

METALOCENE. YOUR PREPARATION AND USE IN ALPHA-OLEFINES POLYMERIZATION DESCRIPTION OF THE INVENTION The present invention relates to catalytic components of the metallocene type and their use in the preparation of (co) polymers of C2-C20 olefins, particularly copolymers of ethylene with C3-C2o, preferably C3-C10, even more preferably C3 , alpha-olefins, possibly in the presence of a diene. Metallocenes having cyclopentadienyl derivatives as ligands are known as catalytic components in the preparation of (co) polymers of olefins. For example, EP-A-185,918 describes the preparation of isotactic polypropylene in the presence of a catalyst system comprising alumoxane and ethylene-bis (4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride. US-A-5,268,495 discloses a new method for the preparation of linker metallocenes linking to the cyclopentadienyl ring. According to this document the bridged metallocenes having as cycloplentadienyl derivative ligands have interesting properties and must be capable of (co) polymerizing a wide range of olefins. The new metallocenes that have now been found, capable of (co) polymerizing C2-C20 olefins, particularly of copolymerizing ethylene with C3-C20, preferably C3-10) even more preferably C3 alpha-olefins, possibly in the presence of a diene The (co) polymers thus obtained can have a wide range of molecular weights, can be with or without elastomeric properties and can therefore be applied in various fields. According to this, the present invention relates to a catalytic component for the copolymerization of ethylene with C3-C20, preferably C3-C10, even more preferably alpha-olefins of C3, possibly in the presence of a diene, which has the general formula (I): wherein: A is a cyclopentadienyl derivative having the general formula wherein R1 and R2 are selected from H and CrC3, alkyl radicals, preferably R2 = H and at least one of the two R1 = H; n is an integer from 2 to 18 and is preferably selected from 3, 5, 6 and 10; B is selected from: 1) any of the cyclopentadienyl derivatives A defined in the foregoing; 2) a monofunctional cyclopentadienyl radical (F) selected from cyclopentadienyl, indenyl, fluorenyl and relative derivatives of alkyl, aryl, substituted trialkylsilyl; Q, is a bridge between A and B, is a bifunctional radical selected from: a) an alkylene group of C1-C20. linear, branched or cyclic; b) a substituted alkyl group of silanylene or disilanylene; c) a silaalkylene group substituted with alkyl; M is selected from Titanium, Zirconium, Hafnium, Vanadium, Niobium and is preferably Zirconium; X is selected from halogen, hydrogen, alkyl group of C, -C10, alkoxide group of 0, -0.0, C2-C20 amide group, C2-C20 carboxyl group, C6-C10 aryl group, aryloxy group of C6-C10, C2-C10 alkenyl group, C7-C40 arylalkyl group, C7-C40 alkylaryl group, C6-C40 arylalkenyl group, preferably an alkyl group of C, -C3 or a halogen, preferably chlorine. Bridged ligands A-Q-B and their preparation are described in the co-pending patent application filed by the same applicant as in the Italian patent application IT-A-MI 95/002284. Some examples of the compounds having the general formula (I) are given in figure (1). In particular, they belong to the compounds having the general formula (I) and indicated in figure (1) are: dimethylsilyl-bis (4,5,6,7,8-pentahydroazulen-2-yl) -zirconium dichloride (CP136A, example Nr. 1.1 of Figure 1); [1- (3-methyl-inden-1 -yl) -1-methyl-ethyl-4,5,6,7,8-pentahydroazulen-2-ylchirconium dichloride (CP172, example Nr. 1.2 of Figure 1); [1- (inden-1-yl) -1-methyl-ethyl] -4,5,6,7,8-pentahydroazulen-2-ylchirconium dichloride (CP138E, example Nr. 1.3 of Figure 1); dimethylsilyl-bis- (4,5,6,7,8,9,10,11,12,13-decahydrocyclo-pentacyclododecan-2-yl] zirconium dichloride (CP192, example Nr. 1.4 of Figure 1); 1, 2-bis- (4,5,6,7,8-pentahydroazulen-2-yl) -tetramethyldisilyl-zirconium dichloride (CP191 C, example Nr. 1.5 of Figure 1); 1 - [4,5,6,7,8-pentahydroazulen-2-yl] -2- [3-methyl-inden-1-yl] -tetramethyldisilyl zirconium dichloride (CP266E, Example Nr. 1.6 of Figure 1). In one embodiment, Q is a linear, branched or cyclic alkylene group having from 1 to 20 carbon atoms. Typical examples are: methylene, ethylene, propylene, butylene, pentylene, hexylene, isopropylene (CH3-C-CH3), isobutylidene, (CH3-C-C2H5), (C2H5-C-C2H5). In another embodiment, Q is a substituted silanylene or disilanylenealkyl group, for example dimethylsilanylene or -Si (CH3) 2-, tetramethyldisilanylene or -Si (CH3) 2-Si (CH3) 2-, methylethylsilanylene, diethylsilanylene. In another embodiment, the group Q consists of Silicon-Carbon sequences, that is, it is a substituted group of sila-alkylenealkyl, for example -Si (R,) 2-C (R ") 2-, wherein R" is a lower alkyl and R "is hydrogen or a lower alkyl Typical examples of sila-alkylene groups are: 1-sila-1,1-dimethylethylene; 2-sila-2,2-dimethylpropylene; 1,3-disila-1 , 1,3-tetramethylpropylene.

In the preferred embodiment Q is selected from the branched alkylene and dialkylsilanylene derivatives, still more preferably selected from isopropylidene, dimethylsilanylene and tetramethyldisilanylene. In the case that B is equal to any of the radicals (A) defined in the general formula (II), in the product having the general formula (I) the group Q forms a bridge with two cyclopentadienyl derivatives both linked to Q in position 2 of the cyclopentadienyl ring. When B is a derivative (F) different from (A), this is a monofunctional cyclopentadienyl radical selected from cyclopentadienyl, indenyl, fluorenyl and the related substituted alkyl, aryl, trialkylsilyl derivatives; in the preferred embodiment (F) is selected from cyclopentadienyl, indenyl and fluorenyl. For simplicity these compounds will be called A-X-C. In the case where B is selected from the radicals F, the point of attachment of the derivatives prior to the bridge Q will be known to those skilled in the art. For example, ndenyl will be linked by itself to Q in position 1, while fluorenyl will be attached to Q from the only non-condensed position of the ring with 5 ends in the chain. The present invention also relates to a process for the preparation of metallocenes having the general formula (I), which comprises the reaction of a compound having the general formula HA-Q-BH (wherein Q, A and B they have the meaning defined in the above) with a metalloalkyl, preferably a lithium alkyl, to give the corresponding dianion, and the subsequent reaction with MX4, preferably with zirconium tetrachloride, to give the compound having the general formula (I ). The reaction scheme, illustrated by butyl lithium and ZrCl4, is as follows: HA-Q-BH + 2LiC4H9 ---- > Li + AQ-ß- Li + + 2C4H10 Li + AQB "Li + + - -> (I) + 2LÍCI A further object of the present invention relates to a process for the homo and copolymerization of C2-C20 alpha-olefins, particularly for copolymerization of ethylene with C3-C10 alpha-olefins, even more preferably with propylene, optionally in the presence of dienes, which utilizes a catalyst system which comprises the compound having the general formula (I). ) polymerization of alpha-olefins, the catalytic system comprises, apart from the metallocene having the general formula (I), also another component (which will be called cocatalyst) selected from alumoxane and compounds having the general formula (III) (Ra) xNH4.xB (Rd) 4 or (IV) (Ra) 3PHB (Rd) 4 or (V) B (Rd) 3, or (VI) CPh3 [(Rd) 4], which by reaction with a metallocene that has the general formula (I) are able to generate catalytic systems of a natural ionic. the general formula (III), (IV), (V) or (VI), the Ra groups, the same or different, are the monofunctional alkyl or aryl radicals, while Rd is the same or different, they are monofunctional aryl radicals, preferably in the form partially or totally fluorinated, even more preferably fully fluorinated. When the compounds have the general formula (III), (IV), (V) or (VI) are used, the catalytic system will consist essentially of the reaction products of one or more metallocenes having the general formula (I), with X equal to H or a hydrocarbyl radical, with any of the compounds having the general formula (III), (IV), (V) or (VI) or their mixture, as described in EP-A-277,004, the molar ratio between the compound having the general formula (III), (IV), (V) or (VI) and the metallocene having the general formula (I) which is between 0.1 and 19, preferably from 0.5 to 6 , still of greater preference from 0.7 to 4. When, in the compound having the general formula (I), X is different from H or a hydrocarbyl radical, the catalyst system having the general formula (I), a compound of alkylation (VII) selected from trialkyl aluminum, dialkyl magnesium or alkyl lithium or other agents of I O alkylation will be known to an expert in the field, and any of the compounds having the general formula (III), (IV), (V) or (VI) or their mixture. The process for the formation of the catalytic system involves pre-mixing the metallocene compound having the general formula (I) with the appropriate alkylating agent (Vil) in solvents of Hydrocarbons, aliphatics or aromatics or their mixtures, at a temperature of between -20 C and + 100 C, preferably from 0 ° C to 60 ° C and even more preferably from + 20 ° C to + 50 ° C, for a time in which it varies from 1 minute to 24 hours, preferably from 2 minutes to 12 hours, even with a greater 5 to 2 hour difference. The mixture is then contacted with a compound having the general formula (III), (IV), (V) or (VI), at the above temperature for a time between 1 minute and 2 hours, preferably between 2 minutes and 30 minutes, and is subsequently fed to the polymerization reactor.

The molar ratio between the alkylation compound (VII) and the compound having the general formula (I) can be 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), (V) or (VI) and the metallocene (I) may vary from 0.1 to 10, preferably from 0.5 to 6, even more preferably from 0.7 to 4. With respect to alumoxane, this is an aluminum compound which, in its linear form, has the general formula (VIII) (Re) 2-AI-O - [- AI (Re) -O-] p-AI ( Re) 2 (VIII), while in its cyclic form, has the general formula (IX) - [- O-AI (Re) -] p + 2 - in which the different Re, the same or different, are selected from the alkyl radicals of C, -C6, aryl radicals of C6-C18 or H, "p" is an integer from 2 to 50, preferably from 10 to 35. The various Re are preferably the same and are selected from methyl, isobutyl , phenyl or benzyl, preferably methyl. When the various Re are different, these are preferably methyl and hydrogen or alternatively methyl and isobutyl, the hydrogen or isobutyl are preferably present, as a number of radicals Re, of between 0.01 to 40% by weight. The alumoxane can be prepared with the various methods known to those skilled in the art. One of the methods comprises, for example, the reaction of a trialkylaluminum compound and / or an aluminum dialkylmonohydride with water (gaseous, solid, liquid or combined, for example such as water crystallization) in an inert solvent, for example toluene. . For the preparation of an alumoxane having different alkyl groups of Re, two different aluminum trialkyls (AIR3 + AIR'3) are reacted with water (see S. Pasynkiewicz, Polyhedron 9 (1990) 429-430 and EP-a- 302,424). The exact structure of alumoxane is not known. 5 It is possible to pre-activate the metallocene with the alumoxane before its use in the polymerization phase. This considerably increases the polymerization activity. The above preactivation is preferably carried out in a solvent, dissolving the metallocene in a solution of an inert hydrocarbon, preferably aliphatic or I O aromatic, even more preferred in toluene. The concentration of the alumoxane in the solution is within the range of 1% by weight up to the saturation value, preferably from 5 to 30% by weight, based on the total weight of the solution. The metallocene can be used in the same concentration but is preferably used in an amount from 104 to 1 mole per mole of alumoxane. The last preactivation from 5 minutes to 60 hours, preferably from 5 minutes to 60 minutes. The temperature is from -78 ° C to 100 ° C, preferably from 0 ° to 70 ° C- The catalytic system of the present invention (catalyst having the general formula (and cocatalyst) can be prepared by putting the catalyst in contact with the catalyst. the cocatalyst in the presence of or without the monomer to be polymerized, inside or outside the reaction reactor The amounts of the catalyst and cocatalyst are not particularly limited., in the case of suspension polymerization, the concentration of the catalyst is preferably in the range of 10'8 to 10"1 moles / liter, even more preferably 10 'to 10" moles / liter, in terms of 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 cocatalyst, the catalyst system may contain a third optional component, usually one or more substances having active hydrogen atoms, such as water, alkanols (for example methanol, ethanol, butanol) or electron donor compounds. such as ethers, esters, amines, compounds containing alkoxy groups such as phenyl borates, dimethylmethoxyaluminium, phenyl phosphate, tetraethoxysilane, diphenyldimethoxysilane. The catalyst and cocatalyst can be introduced separately into the reaction reactor or after they have been brought into contact with each other. In the latter case, the contact can be carried out in the presence of a monomer which is then to be polymerized, thus carrying out the so-called "pre-polymerization". To return the copolymerization process, it is preferable to remove the venom from the catalyst possibly present in the monomers, particularly in propylene. In this case, the purification is carried out with an aluminum alkyl, for example AIMe3, AIEt3, AI (iso-Bu) 3. This purification can be carried out in the polymerization system thereof or, alternatively, before the polymerization by placing the monomers in contact with the aluminum alkyl and subsequently separating them. The catalyst system of the present invention can be applied to the polymerization in the suspension phase (wherein a medium I I Inert is used as a suspending agent, for example propane or butane, possibly propylene by itself and relative mixtures), polymerization in the gas phase and solution polymerization. The catalyst of the invention can obviously be applied to continuous or batch polymerization. When the polymerization is carried out in solvent, the aliphatic and aromatic hydrocarbons can be conveniently used as diluents, either alone or mixed together. The catalytic component having the general formula (I) can be supported on inert carriers. Suitable techniques are known in the literature for supporting the metallocene components on porous solids, for example silica and alumina, possibly in the presence of the cocatalyst. The catalyst system thus supported can be used as such or prepolymerized with alpha-olefinic monomers. Allow to support the heterogeneous catalytic components for sar obtained with a specific morphology and particle size, which are particularly suitable for the polymerization processes in the gas phase. The polymerization temperature is approximately within the range of -78 ° C to 200 ° C, preferably -20 ° C to 100 ° C. There are particular limitations for the olefin pressure in the reaction system, even if the pressure preferably ranges from atmospheric pressure to 5.

Mpa. In the polymerization process, the molecular weight can be controlled with any known method, for example by suitably selecting the polymerization and pressure temperature or introducing hydrogen. The olefins which can be polymerized with the process of the present invention are alpha-olefins (including ethylene) having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms. Typical examples of the 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-ketene, 1 - Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene. The dienes which may possibly be copolymerized with the alpha-olefins, particularly with C2-C3 olefins, are selected, as is known to those skilled in the art, from: - dienes with a linear chain such as 1,4-hexadiene and 1,6-octadiene; - acyclic dienes with a branched chain such as 5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene; 3,7-dimethyl-1,7-octadiene; dihydro de myreceno and dihydroocimeno; alicyclic dienes with an individual ring such as 1,4-cyclohexadiene, 1,5-cyclooctadiene; 1, 5-cyclododecadiene; - dienes having rings linked to the alicyclic bridge such as methyltetrahydroindene; dicyclopentadiene; bicyclo- (2,2,1) hepta-2,5-diene; alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2-norbornene (MNB); 5-ethylidene-2-norbornene (ENB); 5-propenyl-2-norbornene; 5-isopropenyl-2-norbornene; 5-cyclohexylidene-2-norbornene.

Among the non-conjugated dienes typically used to prepare these copolymers, dienes containing at least one double bond in a stretched ring are preferred. The third monomer which is very preferred is 5-ethylidene-2-norbornene (ENB). When the EPDMs are prepared, the diene content in the polymer is less than 15% by weight, preferably from 2 to 10%, the propylene content which is that indicated in the above. More specifically, a further object of the present invention relates to a process in the suspension phase for the preparation of ethylene / α-olefin copolymers or ethylene / α-olefin / diene terpolymers, preferably ethylene-propylene (EPM) ) or ethylene-propylene-diene (EPDM) with a propylene content of between 10 and 75% by weight, preferably from 15 to 70% by weight, which comprises the following steps: 1) an α-olefin and the possible diene, optionally diluted with a hydrocarbon, are fed into a polymerization reactor, at such pressure as is allowed to use the α-olefin in liquefied form; 2) ethylene is added to the mixture obtained in step (1) in an amount sufficient to maintain the desired ethylene / α-olefin ratio in the liquid phase; 3) the catalytic system is added, comprising one or more metallocenes and one or more cocatalysts selected from alumoxane and compounds having the general formula (III) (Ra) xNH4.xB (Rd) 4 or (IV) (Ra) ) 3PHB (Rd) 4, or (V) B (Rd) 3, or (VI) CPh3 [B (Rd) 4], possibly in the presence of an alkylation compound (Vil); 4) the mixture obtained in step (3) is reacted for a sufficient time leaving the polymerization of the ethylene-Zalpha-olefin and diene system possible, characterized in that the catalyst system comprises a metallocene selected from those having the general formula ( I) wherein: A, B, Q, M, X have the meaning defined in the foregoing. When the EPDMs are prepared, the diene content in the polymer is less than 15% by weight, preferably from 2 to 10%, the propylene content which is that indicated in the above. The process for the production of EP (D) M is carried out by means of the polymerization in the suspension phase of ethylene and the alpha-olefin, preferably propylene, and the possible diene, optionally diluted with a hydrocarbon, of low preference boiling C3 to Cs, even more preferred with propane. A catalyst system is suspended in this mixture, consisting of the metallocene having the general formula (I) and the cocatalyst selected from MAO and compounds having the general formula (III) to (VI), and possibly the alkylation compound (VII). ). This catalyst system is present in such an amount to provide a sufficient amount of polymer containing the possible diene. The concentration of the possible diene in the reactor, as a percentage by volume, is from 0.05 to 10%, preferably from 0.2 to 4%.

One embodiment of the present invention in accordance with the suspension process is described below as an illustration. The liquid propylene is fed continuously into a stirring reactor together with the ethylene and the possible diene, optionally diluted with a low boiling of C3-C5 hydrocarbon. The reactor contains a liquid phase consisting essentially of liquid propylene, possible diene monomers, a low boiling hydrocarbon together with gaseous ethylene dissolved therein, and a gaseous phase containing vapors of all the components. The ethylene feed is introduced either as gas in the vapor phase of the reactor or dispersed in the liquid phase, as is known to experts in the field. The components of the catalyst system (catalyst, cocatalyst, optionally the alkylation compound and a possible scavenger) can be charged to the reactor through additional valves, either in the gas or liquid phase, preferably in the liquid phase. The polymerization takes place in the liquid phase that generates a copolymer either soluble or insoluble in the phase thereof, with a residence time of the suspension in the reactor ranging from 10 minutes to 10 hours, preferably from 30 minutes to 2 hours. hours; the long residence time gave 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 jacket in which the cooling liquid circulates or, more preferably, by evaporating and condensing the alpha-olefin (and the possible low boiling hydrocarbon) and feeding them back into the reactor.

The ethylene is fed into the reactor at a pressure higher than the pressure inside the reactor. The ethylene content of the polymer is determined by the ratio between the partial ethylene pressure and the total pressure in the polymerization reactor. This partial ethylene pressure is generally maintained between 0.5 and 50 bar, more preferably between 1 and 15 bar. The temperature of the reactor is maintained between -10 ° C and 90 ° C, more preferably between 20 ° and 60 ° C. With these operating conditions, the ethylene, alpha-olefin and possible diene is polymerized to give an EP (D) M copolymer. The final treatment of the reaction mixture depends on the molecular weight of the copolymer produced. Indeed, the process of the present invention allows the production, which depends on the operating conditions, more specifically that it depends on the metallocene used in the polymerization, of copolymers having different molecular weights which can therefore be used in various fields of the application. The copolymers with a value. Mw of up to 105 can be used for example as bases for the production of additives for lubricating oils and for gaseous oils with dispersion and visco-static characteristics or both. For the highest Mw values, which correspond to the Mooney viscosity (ML1 + 4, 100) greater than 25, the copolymers and terpolymers of the present invention can be applied in the construction of vulcanized end products such as tubes, seals, coatings for electric cables and other technical articles , using formulations known in the art which contain, as a crosslinking agent, peroxides (in the case of copolymers) or sulfur with accelerators (in the case of terpolymers). The following examples are provided for a better understanding of the present invention.

Example 1 Synthesis of dimethylsilyl-bis- (4,5,6,7,8-pentahydroazulen-2-yl) -zirconium dichloride (CP136A). 8.5 ml (0.0136 moles) of 1.6 M LiMe in ethyl ether is added, at room temperature, to the solution of 2.2 g (0.0068 moles) of bis- (2,4,5,6,7,8-hexahydroazulen-2). il) dimethylsilane, prepared as described in Example 1 of Italian Patent Application IT-A-MI 95/002284, dissolved in 100 ml of ethyl ether. The mixture is left under stirring for 4 hours, then cooled to -70 ° C and 1.8 g (0.0077 moles) are added. The temperature is allowed to rise to room temperature, the stirring is maintained for another 2 hours, the mixture is then filtered, washed with ethyl ether and then hexane. It is extracted with methylene chloride concentrate and filtered. The solid is washed with a small amount of methylene chloride then with hexane and finally dried to obtain 0.4 g of the complex (yield of 12% of the ligand used). 1 H NMR (CDCl 3, d ppm ppm TMS): 5.38 (s, 4H); 2.8 (m, 8H); 2.0 (m, 8H); 1.65 (m, 4H); 0.81 (s, 6H). 13 C NMR (CDCl 3, TMS re): -4.49; 29.26; 31.30; 32.60; 101.60; 115.50; 143.16.

Example 2 Synthesis of [1- (3-methyl-inden-1-yl) -1-methyl-ethyl] -4,5,6,7,8-pentahydroazulen-2-yl-zirconium chloride (CP172). 5 0.3 g of t-BuOK are added to a mixture of 4.5 g (0.0336 moles) of 2,4,5,6,7,8-hexahydroazulene, prepared according to Example 1 of the Italian Patent Application A-MI 95/002707, 70 ml of MeOH and 10 ml of acetone and reflux for 20 hours. Then another 2.7 g of t-BuOK are added and the reflux is maintained for another 25 hours. At the end the mixture is poured into water and extracted with ethyl ether. The ether extract after neutralization and anhydrification is evaporated and the residue is puri? Ed by elution on a column on silica gel using petroleum ether. 3.8 g of the fulvene derivative of 2-isopropylidene-2,4,5,6,7,8-hexahydroazulene are obtained as a. yellow solid (65% of performance). Add 12.4 ml of 2.5 M LiBu in hexane at room temperature to a solution of 4.2 g (0.032 mol) of 1-methylindene in 100 ml of ethyl ether. The mixture is left under stirring for 3 hours, then 3.8 g (0.022 mole) of 2-isopropylinden-2,4,5,6,7,8-0 hexahydroazulene is added at -70CC. The temperature is allowed to rise and the mixture is left under stirring for 48 hours. The reaction mixture is hydrolyzed in water and extracted with ethyl ether which after evaporation gives a solid which is purified on a column on silica gel using petroleum ether as eluent. 4.5 g (0.0148 mol) of 2- [1- (3-5 methyl-1 H-inden-1-yl) -1-methyl-ethyl] -1, 4,5,6,7,8-hexahydro are obtained. -azulene which are dissolved in 200 ml of ethyl ether, to which 18.8 ml of 1.6 M LiMe in ethyl ether are added and the mixture is left under stirring overnight. A slightly yellow precipitate forms. The mixture is cooled to -70 ° C and 3.51 g (0.015 mol) of zirconium tetrachloride are added. The temperature is brought to room temperature and the dough tends to take on a dark yellow-brown color. The mixture is filtered, washed with ethyl ether which tends to turn yellow and is then extracted with methylene chloride (2 x 100 ml). The solution is brought to a small volume and 20 ml of ethyl ether are then added. A solid precipitate which is filtered, washed with ether and hexane and then dried. 1.0 g of the complex is obtained. After two days the large orange crystals are separated from the mother liquor of yellow ether, which when filtered and washed with hexane gives 2.1 g of the pure complex for a total of 3.1 g (45% yield calculated on the ligand used) . 1 H NMR (CDCl 3, d ppm ppm TMS): 7.55 (d, 2H); 7.25 (m, 1 H); 6.95 (m, 1 H); 5.65 (s, 1 H); 5.43 (d, 1 H); 2.8-2.5 (m, 4H); 2.45 (s, 3H); 1.9-1.6 (m, 7H): 1.40 (m, 2H).

Example 3 Synthesis of [1- (inden-1-yl) -1-methyl-ethyl] -4,5,6,7,8-pentah-dro-azulen-2-yl-zirconium chloride (CP138E) are prepared 2- [1- (1 H-inden-1-yl) -1-methylethyl] -1, 4, 5,6,7,8-hexahydroazulen, according to that described in Example 2 of Italian Patent Application IT-A-MI 95 / A 002284, which are dissolved in 200 ml of ether and added 15.2 ml. of a 1.6 M solution in LiMß ether. at room temperature. At the end of the addition the mixture is left under stirring overnight. A slightly yellow precipitate forms. The mixture is cooled to -70 ° C and 2.83 g (0.0121 mol) of zirconium tetrachloride are added. The temperature is brought to room temperature and the dough tends to turn a dark brown-yellow color. The mixture is filtered, washed with ethyl ether which tends to turn yellow, and then extracted with methylene chloride (2 x 100 ml). The solution is brought to a small volume and then 20 ml of ethyl ether are added. A solid precipitate which is filtered, washed with ether and hexane and then dried. 0.8 g of the complex are obtained. After two days the large orange crystals I O separates the yellow ether mother liquor, which when filtered and washed with hexane gives 1.6 g of the pure complex for a total of 2.4 g (0.0053 mol, 44% yield). 1 H NMR (CDCl 3) d re. ppm TMS): 7.59 (m, 2H); 7.30 (m, 1 H); 7.05 (m, 1 H); 6.90 (d, 1 H); 6.00 (d, 1 H); 5.42 (d, 1H); 5.25 (d, 1 H); 2.60 (m, 4H); 2.15 (s, 3H); 1.86 (s, 3H); 1.80 (m, 4H); 1.40 (m, 2H).

Example 4 Synthesis of dimethylsilyl-bis- (4,5,6,7,8,9,10,11,12,13-decahydro-cyclopentacyclododecen-2-yl) zirconium dichloride (CP192) 0 2.2g (0.0047 moles) of bis- (4,5,6,7,8,9,10,12,13-decahydro-2H-cyclopentacyclododecen-2-yl) dimethylsilane, prepared as described in Example 3 of the Italian Patent Application IT- A-MI 95/022707, are dissolved in 50 ml of ethyl ether and 5.9 ml of 1.6 M LiMe in ether are added.

The mixture is stirred for 1.5 hours, cooled to -70 ° C and 1.1 g 5 (0.0047 mole) of solid ZrCl are added. The suspension is allowed to return to room temperature, stirred for a further 2 hours, filtered and extracted with methylene chloride. The solution is concentrated and the solid which is precipitated is filtered, washed with a small amount of ether then with hexane and finally dried obtaining 0.66 g (0.0011 mol) of the complex with a yield of 23% of zirconium chloride used. 1 H NMR (CDCl 3, d ppm ppm TMS): 5.51 (s, 4H); 2.59 (t, 8H); 1.6 (m, 8H); 1.30 (m, 24H); 0.63 (s, 6H). 3 C NMR (CDCl 3, TMS re): -5.01; 22.84; 25.12; 25.14; 25.94; 29.50; 114.18; 141.07.

Example 5 Synthesis of 1,2-bis (4,5,6,7,8-pentahydroazulen-2-yl) -tetra-methyldisilyl zirconium dichloride (CP191 C). A suspension of 5.1 g (0.036 mole) of the lithium salt of 2,4,5,6,7,8-hexahydroazulene, prepared as described in Italian Patent Application IT-A-MI 95/002731, is cooled at -70 ° C and 3.4 g (0.018 mol) of 1,2-dichlorotetramethyldisilane are added dropwise. The temperature is allowed to rise to room temperature overnight. The reaction mixture is hydrolyzed and extracted with petroleum ether. In the evaporation of the solvent, 6.5 g of the solid product was obtained which, after grinding in methanol, gave 4.6 g (0.012 mol, 67% yield) of 1,2-bis- (2,4,5,6,7). , 8-hexahydroazulen-2-yl) -tetramethyldisilane. The ligand is dissolved in 160 ml of ethyl ether and 15 ml of 1.6 M LiMe in ethyl ether are added. A solid with a separate elastic appearance. Then 50 ml of THF are added in which the solid subsequently dissolves forming a white crystalline precipitate. The mixture is stirred for one hour and cooled to -70 ° C. 3.2 g (0.0137 mol) of ZrCl4 are then added and the temperature is allowed to rise to room temperature. The mixture is filtered and the white solid is washed with ethyl ether and then with hexane. The residue is extracted with methylene chloride (3 x 50 mL). The volume is reduced to 20 ml and the solid obtained is filtered and washed with a small amount of methylene chloride. 0.82 g of the complex are obtained (13% yield). 1 H-NMR (CDCl 3, d ppm ppm TMS): 6.29 (s, 4H); 2.8 (dt, 4H); 2.55 (dd, 4H); 2.05 (m, 2H); 1.90 (m, 4H); 1.55 (c, 2H); 1.18 (c, 4H); 0.40 (s, 12H). 13 C NMR (d re., Ppm to TMS): -2.3; 28; 30; 32; 116; 124; 138.5.

EXAMPLE 6 Synthesis of 1 - [4,5,6,7,8-pentahydroazulen-2-yl] -2- [3-methyl-inden-1-yl] -tetramethyldisilylzirconium dichloride. (CP266E) 5.1 g (0.036 mole) of lithium salt of 2,4,5,6,7,8-hexahydroazulene are dissolved, prepared as in Example 5 in 200 ml of THF and maintained at -70 ° C. 9.0 g (0.048 mol) of 1,2-dichloro-tetramethyldisilane are added dropwise. The temperature is allowed to rise to room temperature and the solvent is then evaporated. The residue is dissolved in pentane and filtered. The pentane is evaporated and the solid is dissolved in 75 ml of THF and added, at -70 ° C, to a solution of lithium-1-methyl-indenyl prepared from 8.5 g (0.065 mol) of 1-methylindene in 150 ml of THF and 25 ml of LiBu 2.5 M in hexane. The temperature is allowed to return to room temperature, the mixture is hydrolyzed with water and extracted with petroleum ether. After evaporation of the solvent, the residue is purified by elution on a column on silica gel using subsequently petroleum ether and then petroleum ether containing 5% methylene chloride. In this way, 10.4 g are obtained. 3.1 g (0.0082 mol) of the previously prepared ligand are dissolved in 150 ml of ethyl ether and 6.5 ml of 2.5 M LiBu in hexane are added. There is an immediate reaction with the formation of a precipitate. The mixture is left under stirring for 8 hours, then cooled to 60 ° C and 2.1 g (0.009 mole) of solid ZrCl4 are added. The temperature is allowed to rise to room temperature and the mixture is then left under stirring for three hours. The suspension is then filtered and the filtrate concentrated to 15 ml. The solid obtained is then filtered and washed twice with a small amount of ethyl ether and then with pentane. After drying, 1.3 g of the complex (29% yield) are obtained. 1 H-NMR (CDCl 3, ppm Rp TMS): 7.74 (dd, 1 H); 7.62 (dd, 1 H); 7.26 (m, 2H); 6.68 (s, 1 H); 6.38 (d, 1 H); 5.78 (d, 1 H); 2.66 (m, 4H); 2.50 (s, 3H); 1.88 (m, 4H); 1.40 (m, 2H); 0.59 (s, 3H); 0.52 (s, 3H); 0.48 (s, 3H); 0.47 (s, 3H).

POLYMERIC TESTS 1-16 - Synthesis of ethylene / propylene copolymers and ethylene / propylene / diene terpolymers. The polymerizations were carried out in a 3.3-liter pressure-resistant reactor, regulated thermostat and equipment with a magnetic stirrer, according to the following procedure: After washing the reactor with propylene containing aluminum triisobutyl at 5% by weight / volume and washing with fresh propylene, 2 liters of liquid propylene "degree of polymerization" and possibly the third monomer (ENB) is fed at 23 ° C. The reactor is then brought to the preset temperature for polymerization and a solution of hexane at 10% TIBA (triisobutyl-aluminum) corresponding to 1.5 moles of Al is introduced. The optional hydrogen and ethylene in the gaseous form are then added with a tube submerged in the preset relationship to achieve the desired partial pressures. The catalyst is prepared as follows: A metallocene solution in 10 ml of anhydrous toluene is prepared in a glass funnel maintained in a nitrogen atmosphere, to which a solution of 30% methylaluminoxane (MAO) in toluene is added (product commercial WITCO called Eurocen A1 5100 / 30T) in the amount necessary to obtain the desired ratio of Al / Zr. The resulting solution is emptied into a steel barrel maintained in a nitrogen atmosphere and rapidly introduced into the reactor by means of an overpressure of nitrogen. The reactor pressure is kept constant by feeding ethylene from a controlled weight cylinder. After one hour, the ethylene feed is interrupted, the residual monomers are degassed and the reactor is cooled to room temperature. The polymer is discharged and homogenized with a roll mixer and finally characterized. Table 1 indicates: C2 = ethylene content in the liquid phase (mol%); ENB = content of ENB in the liquid phase (% in moles); T = temperature in ° C, H2 = amount of hydrogen (molecular weight regulator) fed into the reactor before the polymerization expressed in moles / liter; MAO / Zr = molar ratio between the cocatalyst and Zr; Yield = polymerization yield (kg of polymer produced / g of Zr feed per hour of production); C3 = propylene content in the polymer produced (% by weight); ENB = content of ENB in the polymer produced (% by weight); = intrinsic viscosity of the polymer in dl / g; Mooney = Mooney viscosity ML (1 + 4, 100 ° C); Mw = average weight of the molecular weight; Mw / Mn = ratio between the average weight of the molecular weight and the average number of the molecular weight.

POLYMERIC TEST 17 Different from the previous examples, this test is carried out using a catalytic system prepared according to the coupled ion of the technique. 2 ml of toluene, 0.3 mg (5.53x10'7 moles) of metallocene CP 191 C, prepared according to that described in Example 5, and a solution of hexane at 10% AI (iso-Bu) 3 so that the molar ratio of Al / Zr equals 300, where they are introduced into a pump of glass test tube with nitrogen. The solution is regulated with thermostat for 1 hour at 20 ° C under stirring, then diluted with 1 ml of toluene and a 0.2% solution in toluene of (C6H5) 3C [B (C6F5) 4] is added so that the ratio molar of B / Zr equals 4. The solution obtained is then fed immediately into a pressure-resistant reactor previously fed with 2 liters of propylene and 0.9 x 10"3 moles of Al (i-Bu) 3, regulated thermostat to 45 ° C and saturated with ethylene to have a content of ethylene at 20 mol% in the liquid phase After 270 hours of copolymer having a propylene content of 39% by weight and a viscosity were discharged after one hour of polymerization. Mooney of ML (1 + 4, 100 ° C) of 23. The polymerization yield was equal to 5400 kilograms per gram of zirconium per hour This example shows that the catalysts of the present invention provide ethylene / propylene copolymers with a productivity high using, as an alternate cocatalyst for MAO, an activator capable of generating a coupling. ionic by means of the reaction with the metallocenes having the general formula (I).

Analysis and Physiochemical Characterizations. The following measurements were carried out on the polymers obtained: Propylene content and ENB content: The determination is carried out through IR on the polymers in the form of film with a thickness of 0.2 mm, using a FTIR spectrophotometer of Perkin-Elmer model 1760.

Intrinsic Viscosity: The measurements are carried out at 135 ° C with the polymer dissolved in orthodichlorobenzene. The time of fall of the solvent and the solutions are measured with an Ubbelhode-type viscometer increasing the concentrations in the polymer under examination. The extrapolation of the reduced viscosities and the zero concentration ratio provides the intrinsic viscosity value.

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

Mooney Viscosity (1 + 4) This is determined at 100 ° C using a Monsanto viscometer "1500 S", according to the method of ASTM D 1646/68.

TEST 18- Vulcanization The mixture to be vulcanized is prepared using the following formulation (referring to the quantity of 100 parts of EPDM derived from test 15): 55 parts of carbon black; 5 parts zinc oxide; 5 parts peroxide; 1.5 parts of sulfur; 2.25 accelerators; 30 parts of paraffinic oil. The mixture is vulcanized in a pressure sheet at 165 ° C for 40 minutes at 18 MPa. The mechanical characteristics were carried out on the vulcanized test samples taken from the molded sheets. The ultimate tensile strength (ASTM method D 412-68) provided to be = 101 kg / cm2, elongation to break (ASTM D 412-68) = 925%, tension set to 200% (ASTM D 412-68) = 12, Shore A = 54.

TABLE 1 With the metallocenes CP172 (tests 1 and 2), CP138E (test 3), CP136A (tests 9-11) and CP192 (test 16), the copolymers are obtained with a low molecular weight suitable for the preparation of additives for lubrication oils; in particular the CP192 metallocene particularly allows the reduced molecular weight distributions to be obtained (test 16), while the metallocene CP172 is characterized by high catalytic activities. Test 2 shows that the same metallocene terpolymers CP172 with a low molecular weight containing ENB can be obtained. With the copolymers and terpolymers of metallocenes CP191 C and CP266E with a high molecular weight are obtained, particularly suitable for the preparation of vulcanized elastomers, as is also known from the data obtained from the mechanical characterization after vulcanization of the polymer obtained from the test 15.

Claims (14)

1. A catalytic component for the copolymerization of ethylene with C3-C20, preferably C3-C10, even more preferably C3 alpha-olefins, optionally in the presence of a diene, having the general formula (I): characterized in that: A is a cyclopentadienyl derivative having the general formula wherein R1 and R2 are selected from H and C ^ C ^, alkyl radicals, preferably R2 ~ H and at least one of the two R? = H; n is an integer from 2 to 18 and is preferably selected from 3, 5, 6 and 10; B is selected from: i) any of the cyclopentadienyl derivatives A defined in the foregoing; I) a monofunctional cyclopentadienyl radical (F) selected from cyclopentadienyl, indenyl, fluorenyl and relative derivatives of alkyl, aryl, substituted trialkylsilyl; Q, is a bridge between A and B, is a bifunctional radical selected from: a) an alkylene group of C1-C2o, linear, branched or cyclic; b) a substituted alkyl group of silanylene or disilanylene; c) a silaalkylene group substituted with alkyl; M is selected from Titanium, Zirconium, Hafnium, Vanadium, Niobium; X is selected from halogen, hydrogen, C-C10 alkyl group, alkoxide group of 0, -0.0, C2-C2 amide group, C2-C20 carboxyl group, C6-C10 aryl group, aryloxy group, C6-C10, C2-C alkenyl group or »C7-C40 arylalkyl group, C7-C40 alkylaryl group, C6-C40 arylalkenyl group.

2. The catalytic component according to claim 1, characterized in that M is Zirconium.

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

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

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

6. The catalytic component according to claim 1, characterized in that Q is selected from branched alkylene derivatives, dialkylsilanylenes and substituted tetraalkyl disylanylenes.

7. The catalyst component according to claim 6, characterized in that Q is selected from isopropylidene, dimethylsilanylene and tetramethyldisilanylene.

8. The catalyst component according to claim 1, characterized in that, when group B is different from group A, group B is selected from cyclopentadienyl, indenyl and fluorenyl.

9. The catalytic component according to claim 1, characterized in that R2-H and at least one of the two R., = H.

10. A process for the preparation of the catalytic component having the general formula (I), which is characterized in that it comprises the reaction of a compound having the general formula HA-Q-BH (in which Q, A and B have the meaning defined in the above) with a metallocene to give the corresponding dianion and the subsequent reaction with MX4, to give the compound having the general formula (I).

11. The process according to claim 10 for the preparation of the compound having the formula (I), wherein M = Zr, characterized in that the metallocene is a Lithium alkyl and the compound MX4 is Zirconium tetrachloride.

12. A process for the homo and copolymerization of C2-C20 alpha-olefins, particularly for the polymerization of ethylene with C3-C10 alpha-olefins, even more preferably with propylene, optionally in the presence of dienes, using the catalytic system, which is characterized in that it comprises the compound having the general formula (I).

13. A suspension process for the preparation of ethylene / α-olefin copolymers or ethylene / α-olefin / diene terpolymers, preferably ethylene-propylene (EPM) or ethylene-propylene-diene (EPDM) with a propylene content of between 10 and 75% by weight, which is characterized in that it comprises the following steps: i) an α-olefin and the possible diene, optionally diluted with a hydrocarbon are fed into a polymerization reactor, at such pressure as is allowed to use the α-olefin in liquefied form; ii) ethylene is added to the mixture obtained in step (1) in an amount sufficient to maintain the desired ethylene / α-olefin ratio in the liquid phase; iii) the catalyst system is added, comprising one or more metallocenes and one or more cocatalysts selected from alumoxane and compounds having the general formula (III) (Ra) xNH4.xB (Rd) or (IV) (Ra) 3PHB (Rd) 4, or (V) B (Rd) 3, or (VI) CPh3 [B (Rd) 4], possibly in the presence of an alkylation compound (Vil); iv) the mixture obtained in step (3) is reacted for a sufficient time leaving the polymerization of the ethylene / alpha-olefin and diene system possible, characterized in that the catalyst system comprises a metallocene selected from those having the general formula (I) wherein: A, B, Q, M, X have the meaning of conformity in claim 1.

14. The process according to claim 13, characterized in that the ethylene-propylene (EPM) or ethylene-propylene-diene copolymers (EPDM) are prepared with a propylene content of between 15 and 70% by weight.