MXPA99010612A - Catalysts based on vanadium, their preparation and use in the (co)polymerization of alpha-olefins - Google Patents

Abstract

Vanadium complex having general formula (I) (RCOO)mVXpLm wherein R is a monofunctional hydrocarbon radical having from 1 to 20 carbon atoms and from 1 to 6 halogen atoms, selected from chlorine and bromine, preferably chlorine;X is chlorine or bromine, preferably chlorine;L is an electron donor;p+n=3, 4 or 5, preferably=3;n is greater than or equal to 1;m is between 0 and 3. The preparation of the above complex is also described together with its use in the (co)polymerization of alpha -olefins.

Description

CATALYSTS BASED ON VANADIO, ITS PREPARATION AND USE IN THE (CO) POLYMERIZATION OF ALPHA-OLEFINES DESCRIPTION OF THE INVENTION The present invention relates to a catalyst based on -Vanadium, its preparation and its use in the (co) polymerization of α-olefins. More specifically, the present invention relates to a catalyst consisting of a Vanadium complex, a co-catalyst based on alkyl Al and, optionally, a reactivator. In addition, the present invention relates to a process for the (co) polymerization of α-olefins in the presence of the catalyst. At present catalysts based on Vanadium consists of a Vanadium complex, an alkyl Al and a chlorinated reactivator. The vanadium complex is the precursor of the active species, which is formed by interaction with alkyl Al. This species initiates polymerization, but is also easily deactivated by the same Al alkyl, producing a reduction in its activity. The reactivator has the function of re-establishing the active species, guaranteeing a longer life of the catalyst, and consequently a greater catalytic activity (see G. Natta et al., Makromol, Chem., 81, 161-172 (1965; E. Adisson, J. Pol. Sci., Part A: Polymer Chemistry, Vol. 31, pages 831-839, 1993.) To have catalytic activity, however, at least one of the reactants must be chlorinated (see G Natta et al., J. Polym, Sci., Vol. 51, 411-427, 1961) In fact systems such as V (acac) 3 / AlEt2Cl or VC14 / A1 (C6H? 3) 3 are active in the copolymerization. of ethylene with propylene, while other chlorine-free systems such as V (acac) 3 / Al (i-Bu) 3 and V (acac) 3 / AlMe3 do not produce a polymer, but become active when a chlorinated reactivator is added such as CI3CCOOR, CC14 to the system (see Adisson et al., J. Pol. Sci., Part A, Polymer Chemistry, Vol. 32, pages 1033-1041, 1994) .The presence of chlorine in the The catalytic system is particularly harmful in the case of the production of ethylene-propylene elastomeric copolymers (EPR and EP (D) M) with a suspension process which does not comprise a purification phase of the catalytic residues, and in particular chlorine. This inevitably causes a lower purity of the products, and consequently excludes their use in particular fields of application. (for example cables). In addition, the presence of inorganic chlorine in the polymer can develop hydrochloric acid during polymer processing, making it necessary to use anti-acid additives, with a consequent increase in running costs. The demand for catalytically active vanadium catalysts in the presence of the smallest possible amount of chlorine, with activities comparable to or superior to those of the prior art, therefore remains unfulfilled. A new group of catalysts has now been found, capable of providing copolymers containing a small amount of residual chlorine. These catalysts are based on Vanadium complexes having halogenated carboxyl groups as ligands. A first object of the present invention therefore relates to a Vanadium complex having the general formula (I): (RCOO) nVXpJLJi? I (I) wherein R is a monofunctional hydrocarbon radical having from 1 to 20 carbon atoms, and from 1 to 6 halogen atoms, selected from chlorine and bromine, preferably chlorine; X is chlorine or bromine, preferably chlorine; L is an electron donor; p + n = 3, 4 or 5, preferably = 3, n is greater than or equal to 1; it is between 0 and 3.

Examples of carboxyl groups R-COO in formula (I) are selected from: 1) R-COO = i I R2_C- (-C-) -COO I I 'R3 R5 wherein Ri, R2, R3, R4 and R5, the same or different, are selected from H, Cl or Br, alkyls, cycloalkyls, aryls, arylalkys, alkylaryls or alkyls, cycloalkyls, aryls, arylalkys, alkylaryls containing chlorine or bromine , with the proviso that at least one of the residues R? ~ R5 is selected from chlorine or bromine, or an alkyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group containing chlorine or bromine; q ranges from 0 to 10. The non-limiting examples of these derivatives are represented by: Cl3COO, CCl3CH2COO, CCI3 (CH2) 2COO, CHCl2COO, CH3CCl2COO, C6H5CC12CH2C00, (C6H5) 2CCICOO, CH3CH2CCl2COO, C6H3CH2CH2CHC1C00, C1C6H4CHC1C00, C1C6H4CH2C00, 2-cyclopropyl-2, 2-dichloroacetic acid.

R-COO = in. where: Ri R2, R3 and R / the same or different, are selected from H, Cl or Br, alkyls, cycloalkyls, aryls, arylalkys, alkylaryls or alkyls, cycloalkyls, aryls, arylalkys, alkylaryls containing chlorine or bromine, with the condition that at least one of the residues R1-R4 is chlorine or bromine, or an alkyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group containing chlorine or bromine; r and s vary independently from 0 to 5, with the restriction that r + s is from 1 to 5. The non-limiting examples of these derivatives are represented by: Cl3CC6H4COO, C1CH2C6H4C00, C1CH2C6H2C12C00, C6H5COO. 3) R-COO = wherein: Z, Ri, R2, R3, R4 and R5, R6, the same or different, is selected from H, Cl or Br, alkyl, cycloalkyl, aryl, arylalkyl, alkylaryl or alkyl, cycloalkyl, aryl, arylalkyl, alkylaryl containing chlorine or bromine, with the proviso that at least one of the residues Z and R? ~ Rß is chlorine or bromine, or an alkyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group containing chlorine or bromine; t and u independently vary from 0 to 10, preferably from 0 to 2. The non-limiting examples of these derivatives are represented by: CCl3CH = CHCOO, CC13CC1 = CC1C00, CC12 = CC1CC12C00. 4) R-COO wherein R is selected from cycloalkyl, polycycloalkyl, cycloalkenyl, polycycloalkenyl having from 3 to 20 carbon atoms, substituted with at least one chlorine or bromine, or with hydrocarbyl group containing at least one chlorine or bromine. Non-limiting examples of these derivatives are represented by: 2-chloro-cyclohexane carboxylic acid, 2,2-dichlorocyclopropane-carboxylic acid, 2,2,3,3-tetrachlorocyclopropane-carboxylic acid, perchlore-cyclohexane carboxylic acid, cyclohex-2-en-2-trichloromethyl-carboxylic acid. As regards L, ie the electron donor, typical examples are the alkyl and cycloalkyl ethers, alkyl esters of aromatic and aliphatic carboxylic acids, aliphatic ketones, aliphatic amines, aliphatic alcohols. L is preferably selected from tetrahydrofuran (THF), dimethoxymethane, and diethoxyethane. A second object of the present invention relates to the process for the preparation of the complexes having the general formula (I), which comprises: a) treatment of a thallium salt (TI) having the general formula RCOOTl, wherein R has the meaning defined above, with a Vanadium halide, preferably VC13, in an aliphatic or aromatic, ether or chlorinated hydrocarbon solvent, alone or in a mixture, preferably THF and dimethoxyethane, at temperatures in the range from 0 to 50 ° C , preferably from 15 to 30 ° C, for a time in the range from 30 minutes to 6 hours, preferably from 1 to 4 hours; b) separation, preferably filtration, of the TI halide formed by the reaction; c) Vanadium complex isolation.

In the preferred embodiment, step (c) is carried out by solvent evaporation or precipitation of the complex by the addition of a suitable precipitating agent, usually a hydrocarbon solvent, preferably pentane. Typical but non-limiting examples of these syntheses are given in the experimental section, which describe, among others, the preparation of V (CC13C00) 3 by reaction between VC13 and T1 (CC13C00) in a molar ratio 1/3, V ( CH2C1-C6H4-COO) 3 by reaction between VC13 and CH2C1-C6H4-C00T1 in a molar ratio 1/3, V (CC13C00) 2C1 by reaction between VC13 and T1 (CC13C00) in a molar ratio, V (CC13CH2CH2C00) 3 reaction between VC13 and CC13CH2CH2C00T1 in a 1/3 ratio. A third object of the present invention relates to a catalytic system for the (co) polymerization of α-olefins, which consists of: (a) Vanadium complex having the general formula (I), (b) derived from aluminum organ which has the general formula (II) AlRnXm, wherein R is an alkyl group of 1 to 20 carbon atoms, X is chlorine or bromine, preferably chlorine, and n + m = 3, with the exclusion of the compound having n = 0, (c) optionally a reactivator, preferably chlorinated Among the Vanadium compounds having the general formula (I), those in which RCOO has the general formula (la) CC13- (-CH2-) n-COO (la) where n is an integer between 0 and 2, is say trichloroacetate (n = 0), trichloropropionate (n = 1), trichlorobutyrate (n = 2), have proven to be particularly effective. Typical examples of compounds having the general formula (II) are AlEt2Cl (diethylchloroalumino), AlMe3 (trimethylaluminum), AlEt3 (triethylaluminum), Al (i-Bu) 3 (triisobutylaluminum). In the preferred embodiment the cocatalyst having the general formula (II) has an alkyl group of 1 to 20 carbon atoms such as R, n = 3 and m = 0. Even more preferably R is an isobutyl group. The molar ratio between the cocatalyst having the general formula (II) and the catalyst having the general formula (I) is between 1 and 500, preferably between 3 and 100, more preferably between 20 and 50. When, in the cocatalyst that has the general formula (II), m is different from 0, the preferred cocatalyst is diethylchloroaluminum. When, in the cocatalyst having the general formula (II), m = 0, the preferred cocatalyst is triisobutylaluminum. In the preferred embodiment the molar ratio between cocatalyst and catalyst is between 5 and 10. As regards the reactivator, this is usually selected from chlorinated organic compounds, for example ethyl trichloroacetate, n-butyl perchlorocrotonate, diethyl dichloromalonate, tetrachloride of carbon, and chloroform. The molar ratio between the possible reactivator and the vanadium can vary from 0: 1 to 100: 1, preferably from 1: 1 to 40: 1, even more preferably between 1: 1 and 10: 1. When, in the cocatalyst having the general formula (II), m is different from 0, the preferred reactant is ethyl trichloroacetate, and the preferred molar ratio between reactivator and vanadium is between 4: 1 and 10: 1. When, in the cocatalyst having the general formula (II), m is equal to 0, the preferred reactivator is carbon tetrachloride, and the preferred molar ratio between reactivator and vanadium is between 10: 1 and 50: 1. preferred the reactivator is not used. The catalysts of the present invention can be used in processes of (co) polyacrylation of α-olefins in liquid phase (solution or suspension) at low or medium pressure (15-50 ate) and at temperatures in the range from -5 to 75 ° C. In the preferred embodiment, the temperature is between 25 and 60 ° C, and the pressure between 6 and 35 ate. The polymers and copolymers thus obtained have very high average molecular weights. If the molecular weight is to be regulated at a lower value, hydrogen can be used as a molecular weight regulator. The catalyst for the (co) polymerization of α-olefins and the terpolymerization with dienes is prepared by contacting the alkyl Al with the complex of V dissolved in an aliphatic or aromatic hydrocarbon solvent and, optionally, with the reactivator. The contact can take place separately without the mixture of olefins to be polymerized, for a time in the range from 1 minute to 30 minutes, preferably from 5 to 20 minutes, at a temperature in the range from 0 ° C to 50 ° C, preferably from 15 ° C to 40 ° C, or it can take place in the polymerization reactor in the presence of the monomer mixture. In this case the three reagents can be added separately, or as a mixture of two of these. The catalyst is preferably formed "in situ" by introducing the alkyl Al into the autoclave that already contains the solvent (heptane or liquid propylene), the mixture of reactants and, optionally, the thermometer, and adding the solution of the V complex with the possible reactivator in toluene. The catalysts of the present invention can be used in the polymerization of α-olefins, preferably in the polymerization of ethylene, in the copolymerization of ethylene with propylene and higher α-olefins, and in the terpolymerization of ethylene with propylene and dienes to give polymers with a density in the range from 0.96 g / cm3 to 0.86 g / cm3 . The copolymerization of ethylene-propylene to give elastomeric EPR copolymers and the terpolymerization of ethylene-propylene-non-conjugated diene to give EP (D) M rubbers are particularly preferred. The diene can be selected from: - alicyclic dienes with a linear chain such as 1,4-hexadiene and 1,6-octadiene; - acyclic dienes with a branched chain such as 5-methyl-l, 4-hexadiene, 3,7-dimethyl-l, 6-octadiene, 3,7-dimethyl-l, 7-octadiene; alicyclic dienes with a single ring, such as 1,4-cyclohexadiene, 1,5-cyclooctadiene; dienes having condensed and bridged alicyclic rings, such as methyltetrahydroindene, 5-ethylidene-2-norbornene (ENB), 5-propenyl-2-norbornene. In the preferred embodiment, the diene is ENB or 1-methylene-2-vinyl-cyclopentane. The elastomeric copolymers of EPR and EP (D) M which can be obtained with the catalysts of the present invention contain from 20 to 65% by mol of propylene, and amounts not exceeding 15% of ENB. The weight average molecular weight of the polymer obtained in the presence of hydrogen ranges from 50,000 to 500,000. The following examples provide a better illustration of the present invention.

EXAMPLES The characterization by means of 1 H NMR spectroscopy, mentioned in the following examples, was carried out with a Bruker MSL-200 spectrometer. The characterization by means of FTIR spectroscopy was carried out on a Perkin-Elmer 1800 FTIR spectrometer with a resolution of 4 cm "1 and 64 scans.The determination of vanadium was carried out on an inductively coupled plasma spectrometer (ICP) Perkin-Elmer Plasma II with Atomic Emission Detection (AES) The determination of total chlorine was carried out with a sequential X-ray fluorescence (XRF) Phillips PW 1404/10 spectrometer with a double anode tube of Sc / Mo The total chlorine was obtained from the sum of the inorganic chlorine (ie, chlorine bound to V and / or Al) and organic chlorine (ie, chlorine attached to a hydrocarbyl residue) .The measurement was carried out on alcoholic solutions. of the vanadium complex diluted with MilliQ water in 2% by weight of HN03 in a ratio of 1: 100 for the determination of V, and 1: 1 for that of chlorine, the concentrations of V and Cl were calculated on the basis of a calibration curve obtained with reference solutions with a known titer of the element to be determined (V or Cl) and having a composition identical to that of the samples (water, EtOH, HN03). The inorganic Cl determination was carried out potentiometrically, using a Ti troprocessor 670 and an Ag electrode (code 6.0404.000) filled with a saturated solution of KN03 (both Metrohm). The alcoholic solution of the sample was acidified with 3 M H2SO 3, and it was evaluated with 0.1 N AgN03. The molecular weight measurement was carried out by Gel Permeation chromatography (GPC). The analyzes of the samples were carried out in 1,2,4-trichlorobenzene (stabilized with N, N'-m-phenylenedimaleimide) at 135 ° C with a WATERS 150-CV chromatograph, using a Waters differential refractometer as a detector. Chromatographic separation was obtained with a set of μStyragel HT (Waters) columns with pore dimensions of 103, 104, 105 and 106 A, establishing an eluent flow rate of 1 ml / minute. The data was obtained and processed through the Máxima 820 program set version 3.30 (Millipore). The calibration curve used to calculate the average molecular weight of number (Mn) and weightJ (Mw) was obtained using standard polystyrene samples with molecular weights in the range of 6,500,000 - 2,000, and applying the Mark-Houwink equation valid for linear polyethylene and polypropylene; the molecular weight values were corrected in relation to the polymer composition, using the Scholte equation.

The propylene content in the ethylene-propylene copolymers was determined on samples in film form, using a Perkin-Elmer 1800 FTIR spectrometer with a resolution of 4 c "1 and 64 scans, measuring the band absorptions at 4390 and 4255 cm "1, in the ethylene-propylene-ENB terpolymers measuring the bands at 4390, 4330, 4255 and 1688 cm" 1, and on the basis of calibration curves prepared with copolymers and terpolymers respectively with a known composition.

EXAMPLE 1 Synthesis of comparative catalyst (I) V (CCl3-CO-CH-CO-CH3) 3 3 g (15 mmol) of acetylacetone (CH3-CO-CH2-CO-CH3) were added to an aqueous solution of Na2CO3 ( 0.79 g, 75 mmol in 100 ml); The mixture was left under vigorous stirring for 15 minutes at room temperature. 100 ml of chloroform was then added, and a solution of VC13 obtained by dissolving 0.79 g (5 mmoles) of the product in 50 ml of water was added dropwise. The mixture was left under stirring at room temperature for two hours; the organic phase became brown, while the aqueous phase remained colorless. The organic phase was separated and the solvent was evaporated. 2.9 g of a light brown solid were obtained.

Yield: 90% V: 7.48% Cl: 44% Cl / V = 8.6 NMR of XH (in C6D6, d in ppm): cis isomer - 56.8 ppm (CH3); 44 ppm (CH): trans isomer - 73, 61, 54 ppm (CH3); 65, 51, 35 ppm (CH).

EXAMPLE 2 Synthesis of catalyst V (CCl3COO) 3 (THF) n 2a) Synthesis of thallium trichloro acetate - Tl (CCl3COO) .1 g of solid CCl3COOH (0.031 mol) was added to a suspension of 7.0 g of T12C03 (0.0149 mol) in 100 ml of methanol, maintained under stirring. The mixture was left under stirring at room temperature. The solution was then filtered, and the filtrate was evaporated at 15 ° C and 2.72 x 10-2 kg / cm2 (20 mmHg). The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10 ~ 6 kg / cm2 (10"3 mmHg), 10.1 g of thallium trichloroacetate were obtained in the form of a white solid. : 92% IR (in nujol): 1540 cm "1 (v_co) • 2b) Synthesis of the Vanadium (II) V complex (CC13C00) 3 (THF)! 8.43 g (23 mmoles) of TICCI3COO dissolved in 70 ce THF to a solution obtained by dissolving 2.86 g (7.7 mmoles) of VC13 (THF) 3 (Aldrich-97%) in 60 ml of THF. The reaction, carried out for 4 hours at room temperature, took place with the precipitation of a white solid (T1C1) and a color change from red to greenish brown. The precipitate was filtered, the solvent was evaporated and dried under vacuum. 4.5 g of a bright green solid were obtained. Yield: 97% V: 7.98% Cl: 50% Cl / V = 9.1 IR (Nujol): 1600 - 1800 cm "1 (vas? M.C02); 1403 cm" 1; 1263 c "1 (vslm.C02) 2c) Catalyst synthesis V (CC13C0) 3 (THF)? G 84 g (228 mmoles) were slowly added.

T1CC13C00 dissolved in 300 ml of THF to a solution obtained by dissolving 28.5 g (76.2 mmoles) of VC13 (THF) 3 (L. E. Manzer, Inorg. Synthesis, 2? _, 135, (1982)) in 300 ml of THF. The reaction was carried out for 4 hours at room temperature; IT Cl precipitated, and the initially red suspension turned green. The precipitate was filtered and the solvent was evaporated. The obtained product was subsequently dissolved in 200 ml of THF and 600 ml of pentane, and cooled to -40 ° C for two hours. A solid precipitated, which was filtered, washed with pentane and dried at room temperature by hours. 47.5 g of green product were obtained. Yield: 91% V: 7.42% Cl: 47.9% Cl / V = 9.3 THF / V = 1.88 (1H NMR, CD3CN) IR (Nujol): 1650 - 1800 c "1 (vasim.C02); 1263 cm" 1 (vsim.C02). 2d) Synthesis of the catalyst (Ilb) V (CCl3COO) 3 400 mg of the catalyst (lia) was dissolved in about 20 ml of toluene. After a few minutes a precipitate began to separate from the solution. The suspension was allowed to stand for 4 days at room temperature; it was then filtered and the solid dried under vacuum, yielding 200 mg of a light green solid. Yield: 50% V: 9% Cl: 57.1% Cl / V = 9.3 THF = (XH NMR, CD3CN): IR traces (Nujol): 1645 cm "1 (vasim.C02); 1403 cm" 1 (vsim. C02).

EXAMPLE 3 Synthesis of catalyst (III) V (CH2Cl-C6H4-COO) 3 0.92 g (5.8 mmol) of VC13 (Aldrich-97%) were suspended in 150 ml of toluene in a 500 ml; a suspension of 3-chloro-ethylbenzoic acid (CH2Cl-C6H4-COOH, Fluka) in toluene was added (3 g, 17.6 mmol) in 50 ml of solvent). It bubbled NH3 gas for about 2 hours; the initial purple suspension turned brown. After heating to reflux for 5 hours, the suspension became green. It was filtered to remove the formed ammonium chloride, and the filtrate was evaporated under vacuum. 1 g of green product was obtained. Yield: 30% V: 8.39% Cl: 16.4% Cl / V = 2.9 EXAMPLE 4 Synthesis of catalyst (IV) V (CC13C00) 2C1 (THF) i 3.7 g (10 mmol) of VC13 (THF) 3 (Aldrich-97%) were dissolved in 100 ml of THF. 7.3 g (20 mmoles) of CC13C00T1 dissolved in 80 cc of THF were added slowly (in about 3.5 hours) to the resulting solution. The reaction was carried out for 1 hour at room temperature. A precipitate formed (T1C1), and the suspension changed color, changing from red to brown. The precipitates were filtered, the solvent was evaporated and the solid was dried under vacuum. The recovered solid was washed three times with pentane (50 ml each time), filtered and dried with a pump. 4 g of brown solid were obtained. Yield: 83% V: 10.54% Cltot .: 51.35% Cl- • 7 33 Cltct./V = 7 »- L i no rg. / V 1 E JEMPLO 5 Synthesis of the catalyst (V) - V (CCl3CH2CH2COO) 3 (THF)? 5a) Synthesis of 4, 4, 4-trichloro-butironi trilo (Bruson H.

A. et al. J. Am. Chem. Soc. 67, 601, (1945)) 242 ml of CHC13 (3.02 mmoles), 36.0 g of [C6H5CH2N] + [(CH3) 3C1] ~ (0.196 moles, BTMAC1) and 11.0 g were charged. of KOH (0.196 moles) in 27 ml of water in a three-necked flask equipped with a mechanical stirrer, addition funnel and a two-way fitting connected to a stream of nitrogen, and a thermometer. After cooling to 0-5 ° C by means of a cryostat, 300 ml of CH2 = CHCN (4.56 moles) was added in about three hours. The mixture was left under stirring at this temperature for 24 hours. The reaction mixture was washed three times with water. The aqueous phase was extracted with ethyl ether. The ether phase and the chloroform phase were united and concentrated. The mixture was distilled by collecting the fraction that passed at 91-103 ° C (2.17 x 10 ~ 2 kg / cm2, 16 mmHg). The distillate obtained, which solidified in the flask, weighed 91.0 g. Yield: 17% TH NMR (in CDC13 d in ppm): 3.08 (2 H, t), 2.85 (2 H, t). IR (in Nujol): 2260 cm "1 (V-CN) b) Synthesis of 4, 4, 4-trichlorobutyric acid 40.5 g of 4,4,4-trichlorobutyroni trile (0.236 mol) and 170 ml of concentrated HCl were charged In a 250 ml flask, the mixture was left under stirring at 60 ° C for six hours, the solid acid was precipitated and filtered, washed with water and dried with a mechanical pump, 43.4 g of acid were obtained. , 4-trichlorobutyric Yield: 97% Melting point: 54.8 ° C (read 55 ° C) 1K NMR (CDC13 d in ppm): 10.82 (1 H, broad s), 3.15 (2 H, t), 2.92 (2 H, t) IR (in nujol): 3260 cm "1 (V_0H) 1720 cm" 1 (v-co) • c) Synthesis of 4, 4, 4-thallium trichlorobutyrate A solution of 12.0 g of CC13CH2CH2C00H (0.063 mol) "in 20 ml of methanol was added to a suspension of 12 g of T12C03 (0.026 mol) in 100 ml of methanol, kept under stirring. The mixture was subsequently diluted with 50 ml of methanol, and left under stirring for 2 hours at room temperature. The solution was then filtered, and the filtrate was evaporated at 20 ° C and 2.72 x 10"2 kg / cm 2 (20 mmHg) The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10"6 kg / cm2 (10 ~ 3 mmHg). The thallium salt obtained as a white solid weighed 17.6 g. Yield: 86% lR NMR (in CD3OD, d in ppm): 3.01 (2 H, t), 2.62 (2 H, t). IR (in nujol): 1540 cm "1 (v_Co) d) Synthesis of the vanadium complex (V) 3.19 g of VC13- (THF) 3 (8.54 mmoles) dissolved in 160 ml of anhydrous THF were charged into a 250-ml flask 10 ml of three mouths, 10.11 g (26.61 mmoles) of solid CC13CH2CH2C00T1 were slowly added in. The solution changed color (light red to dark green), the solution was left under stirring for about 4 hours, filtered and the filtrate was green. The resulting solid was dried at 1.36 x 10 ~ 6 kg / cm2 (10 ~ 3 mmHg) for 24 hours 4.44 g of complex were obtained Yield: 75% V: 7.55% Cl: 50.2% Cl / V: 9.5 EXAMPLE 6 Synthesis of catalyst (VI) - V (CHC12C00) 3 (THF)? a) Synthesis of thallium dichloroacetate-TI (CHCl2COO) A solution of 3.5 ml of CC12HCC0H (0.045 mole) in 20 ml of methanol was added to a suspension of 9.37 g of T12C03 (0.020 mole) in 100 ml of methanol, kept low agitation. The mixture was diluted with 50 ml of methanol, and left under stirring for 2 hours at room temperature. The solution was then filtered, and the filtrate was evaporated at 15 ° C and 2.72 x 10"2 kg / cm 2 (20 mmHg) The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10"6 kg / cm2 (10 ~ 3 mmHg). The thallium salt obtained as a white solid weighed 10.2 g. Yield: 76% XH NMR (in CD3OD, d in ppm): 5.93 (1 H, s).

IR (in nujol): 1580 c "1 (v_co) b) Synthesis of the Vanadium complex (VI) 3.21 g (0.00863 mol) of VC13- (THF) 3 in 250 ml of anhydrous THF were charged, under argon, in a 500 ml test tube, and 8.58 g (0.02589 moles) of TI (CCl2HCOO) were added.After 15 hours, the T1C1 was filtered and washed with THF.The solvent was evaporated, and the solid was dried with a pump mechanics at 50 ° C, due to the difficulty in solidification of the green residue, 26 g of complex were obtained Yield: 59% V: 10.06% Cl: 37.5% Cl / V = 5.4 EXAMPLE 7 Synthesis of catalyst (VII) - V (CCl3CH2COO) 2C1 (THF) X a) Synthesis of 2,4,4,4-tetrachlorobut-l-ene A1C13 2CH2 = CC12 CH2 = CC1CH2CC13 80 ml of 1,2-dichloroethane and 166.6 ml of 1,1-dichloroethylene (2.46 moles) were charged into a thnecked flask equipped with a mechanical stirrer, a two-way fitting connected to a stream of nitrogen, and a thermometer . The mixture was cooled to -10 ° C and 14 g (0.105 moles) of anhydrous A1C13 were added. The temperature was slowly brought to -25 ° C, and the mixture was left under stirring for 8 hours. The solution became a dark blue color. The mixture was then hydrolyzed with water and ice, and the temperature was prevented from exceeding -20 ° C. It was extracted with methylene chloride, washed with water until neutral, and dried over Na2SO4. The excess solvent was distilled at 30 ° C and 2.72 x 10"2 kg / cm2 (20 mmHg) .The residue was distilled at 12.24 x 10 ~ 4 kg / cm2 (0.9 mmHg), resulting in 53.0 g of product. : 22.3% NMR of XH (in CDC13, d in ppm): 5.6 (1 H, t), 5.55 (1 H, t), 3.67 (2 H, s) b) Synthesis of acid 3, 3, 3- trichloropropionic MnO, CC13 CH2 CC1 = CH2 CC l 3CH2 COOH 6 g of tetrachlorobutene, 1 g of sodium carbonate, 250 ml of water and 13.7 g of potassium permanganate were charged into a 750 ml flask equipped with a mechanical stirrer and thermometer. The whole mixture was left under stirring, and the temperature was maintained at about 45 ° C with water and ice. Subsequently, 6 g of tetrachlorobutene and 13.7 g of KMn04 were added at regular intervals of 15 minutes, five times until a total of 30 g of tetrachlorobutene had been added. Then 54.0 g of sodium bisulfite were added, together with enough dilute sulfuric acid to have a clear solution. The solution was extracted with ethyl ether, washed with water, dried over sodium sulfate and the solvent was evaporated. 15.0 g of acid were obtained as a yellowish solid. Yield: 45% XH NMR (in CDC13, d in ppm): 10.50 (1 H, broad s), 3.83 (2 H, s). c) Synthesis of thallium 3, 3, 3-trichloropropionate TI (CC13CH2C00) 5.14 g (0.029 mole) of solid 3, 3, 3-trichloropropionic acid was added to a suspension of 6.80 g (0.0145 mole) of T12C03 in 100 ml of methanol, maintained under agitation. The mixture was left under stirring for 1 night at room temperature. The solution was then filtered, and the filtrate was evaporated at 15 ° C and 2.72 x 10"2 kg / cm 2 (20 mmHg) The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10"6 kg / cm2 (10" 3 mmHg) 10.05 g of thallium salt were obtained in the form of a white solid Yield: 89.6% XH NMR (in CD3OD, d in ppm): 4.85 (2 H, s) d) Synthesis of the V (VII) complex 2.5 g (0.0067 mole) of crystalline VC13, 7.34 g (0.019 mole) of CC13CH2C00T1 and THF were charged to dissolve the complete mixture in a 500 ml test tube. The mixture was kept under stirring for * about 15 hours.The mixture was then filtered, the filtrate was dried under vacuum, and the g solid formed weighed 5.12 g Yield: V: 9.84% Cl: 43.5% Cl / V = 6.3 EXAMPLE 8 Synthesis of catalyst (VIII) - V (CH3CCl2COO) 3 (THF) 2 a) Synthesis of thallium 2, 2-dichloropropionate TI (CH3CC12C00) 6.83 g (0.0477 moles) of acid were added 2, 2-dichloropropionic to a suspension of 11.28 g (0.0248 moles) of T12C03 in 180 ml of methanol, maintained under stirring. The mixture was left under stirring for 1 night at room temperature. The solution was then filtered, and the filtrate was evaporated at 15 ° C and 2.72 x 10"2 kg / cm 2 (20 mmHg) The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10"6 kg / cm2 (10" 3 mmHg) 15.05 g of thallium salt were obtained in the form of a white solid Yield: 93.8% 1 R NMR (in CD3OD, d in ppm): 4.5 (3 H, s) d) Synthesis of V complex (VIII) 1 g (2.66 mmoles) of VC13- (THF) 3 dissolved in 60 ml of anhydrous THF was charged in a 150 ml test tube under argon 2.81 were added slowly g (8.06 mmoles) of solid CH3CC12C00T1 The solution changed color, it was left under stirring for about 4 hours, and then it was filtered The solvent of the g solution was evaporated, and the resulting solid was dried at 1.36 x 10" 6 kg / cm2 (10 ~ 3 mmHg) for 24 hours. 1.29 g of complex o were obtained. Performance: 87% V: 8.21% Cl: 30.7% Cl / V = 5.4 EXAMPLE 9 Synthesis of the catalyst (IX) -V (CCl3CH = CHCOO) 3 (THF)? a) Synthesis of 4, 4, 4-trichlorobut-2-enoic acid Synthesis of tris (triphenylphosphine) ruthenium dichloride MeOH RuCl3-H20 + (C6H5) 2P - »- Ru (PPh3) 3Cl2 0.5 g of RuCl3-H20 was dissolved under argon in 150 ml of anhydrous methanol, and the solution was heated to reflux for 5 minutes. Then it was brought to room temperature, and 2.3 g of triphenylphosphine was added. Then it was brought to the reflux temperature again for three hours. The solution was subsequently cooled to room temperature, the solid obtained was filtered and dried with a mechanical pump.

Synthesis of 4, 4, 2-tetrachlorobutenoate butyl 12 g (94 mmol) of butyl acrylate, 200 mg of RuCl2 [PPh3] 3 and 28 ml of carbon tetrachloride were charged into a 500 ml flask under argon. The mixture was brought to 90 ° C for about 4 hours. The termination of the reaction was observed by means of GC control. The mixture was cooled, petroleum ether was added, and the triphenylphosphine precipitated was filtered. The solvent was evaporated, and 13 g of crude product were obtained, which were used directly in the subsequent step. Synthesis of 4, 4, 4-butyl trichlorobut-2-enoate COOBu 6 g (22.4 mmol) of butyl 4,4,4,2-tetrachlorobutanoate in 20 ml of anhydrous toluene were charged into a 250 ml flask under inert gas, and 5 ml of 1,8-diazabicyclo [5.4. 0] undecan-7-ene (DBU) with exotherm. The temperature was brought to 60 ° C for 3 hours. The termination of the reaction was observed by means of GC control; the mixture was cooled, water was added, the mixture was extracted with ethyl ether and anhydrous over Na2SO4. The residue obtained after evaporation of the solvent and purified by chromatography on silica gel (eluent: hexane / ethyl acetate = 9/1) weighed 4 g. Yield: 76% Synthesis of 4, 4, 4-trichlorobut-2-enoic acid 17.82 g of LiOH in 20 ml of water were added to a solution containing 3 g (0.0128 mol) of butyl 4,4,4-trichlorobut-2-enoate in 300 ml of THF. The mixture was stirred for 1 hour at room temperature. It was then brought to neutral pH with the addition of 1N HCl, extracted with ethyl acetate and rendered anhydrous over Na2SO4. The solid obtained after evaporation of the solvent under reduced pressure and washing with petroleum ether weighed 2.1 g. Yield: 87% b) Synthesis of thallium TI 4, 4, 4- trichlorobut-2-enoate (CC13CH = CHC00) 1.56 g (8.4 mmol) of 4, 4, 4-trichlorobut-2-enoic acid were added to one suspension of 1.94 g (4.2 mmol) of T12C03 in 80 ml of methanol, maintained under stirring. The mixture was left under stirring for 4 hours at room temperature. The solution was then filtered, and evaporated at 15 ° C and 2.72 x 10"2 kg / cm2 (20 mmHg) The solid obtained was washed with ethyl ether (10 x 50 ml) and dried at 1.36 x 10" 6. kg / cm2 (10"3 mmHg) 3.0 g of thallium salt were obtained, in the form of a white solid Yield: 91.2% c) Synthesis of Vanadium complex (IX) 0.80 g (2.15 mmoles) were charged VC13- (THF) 3 dissolved in 60 ml of anhydrous THF in a test tube of 150 ral, under argon, 3 g (6.54 mmoles) of CC13CH = CHC00T1 were slowly added in. The solution changed color. about 4 hours, then it was filtered The green solution, after being washed, was evaporated from the solvent, and the resulting solid was dried at 1.36 x 10"6 kg / cm2 (10-3 mmHg) for 24 hours. 1.40 g of complex were obtained. Yield: 95% V: 7.12% Cl: 40.5% Cl / V = 9.3 EXAMPLE 10 Synthesis of the catalyst (X) V (o-Cl, m-Cl-C6H3-CH2-COO) 3 A suspension of 2,4-dichlorophenylacetic acid (Acros) in toluene (11.3 g, 55 mmol in 150 ml of solvent) was added by siphoning to a suspension of VC13 (Aldrich-97%) in toluene (2.9 g, 18.2 mmol in 100 ml of solvent). NH3 gas was bubbled into the reaction mixture for 2 hours; a white solid formed (ammonium salt of the acid) and the suspension changed color from purple to brown. The mixture was then heated to reflux temperature for 5 hours; the suspension turned green. Its volume was reduced by evaporation under vacuum, and then filtered to remove the ammonium chloride formed. With evaporation of the filtrate, 12 g of a bright green solid product were obtained. Performance: 100% V: 7.82% EXAMPLE 11 Copolymerization of ethylene-propylene in solution Vacuum-nitrogen was applied for at least three times at 90 ° C and for a total duration of about 2 hours, to a Buchi autoclave with a steel reactor of 2 1 equipped with a burette. to move the catalyst, a paddle stirrer, a thermocouple and heating jacket connected to a thermostat for temperature control. Before each test, a cleaning was performed by discharge of the reactor while maintaining under agitation at 90 ° C a solution containing 500 ml of anhydrous heptane and 5 ml of Al (i-Bu) 3 for about two hours. The content of the reactor was discharged by means of a valve located in the lower part, under a low nitrogen pressure and a solution containing 1 1 of heptane and aluminum alkyl of the type and in such an amount with respect to the Al / V ratio desired. The autoclave was pressurized by entering in order 0.2 ate. of hydrogen, 200 g of propylene (4.9 ate.) and 7 g of ethylene (1 ate.) and the complete mixture was regulated with a thermostat at 30 ° C. In this stage, a solution of the vanadium complex was introduced, obtained by dissolving 0.042 mmoles in 10 ml of toluene and, optionally the reactivator, of the type and in such an amount with respect to the ratio of reactivator / Vanadium desired, applying a slight overpressure of nitrogen, by means of the burette located in the upper part of the autoclave . Once the catalyst was introduced, the system was left for the desired time, maintaining a constant pressure by means of an ethylene stream. At the end, the contents of the reactor were discharged under pressure, by means of the valve at the bottom, and coagulated in about 3 1 of ethanol. The polymer was filtered off, washed with acetone and made anhydrous under vacuum at 40 ° C for about 8 hours.

EXAMPLE 12 Copolymerization of ethylene-propylene-ENB in liquid propylene The polymerization was carried out in a 0.5 liter pressure reactor, equipped with a magnetic drag anchor stirrer and external heating jacket connected to a heat exchanger for the control of the temperature. The reactor was previously cleaned by keeping it under vacuum (1019 x 10"6 kg / cm2, 0.1 Pascal) at a temperature of 80 ° C for at least 2 hours At 23 ° C, 120 g of liquid propylene was fed to the reactor. and optionally hydrogen and the diene (ENB), in the amounts indicated in Tables 6 and 7. The reactor was then brought to the polymerization temperature of 40 ° C, and the desired amount of aluminum alkyl was introduced; gaseous ethylene "polymerization grade", by means of a submerged tube, until the desired equilibrium pressure was reached (20-22 ate.) Under these conditions the molar concentration of ethylene in the liquid phase was between 8 and 12%, depending on the total pressure of the system, the desired amount of solution (suspension) of vanadium salt in toluene was transferred under a stream of inert gas to a metal container, from which, by means of an overpressure of nitrogen, I c The polymerization reaction was carried out at 40 ° C, taking care that the total pressure was kept constant by continuously feeding ethylene to compensate for the part that had reacted. After 1 hour, the ethylene feed was discontinued, and the polymerization was stopped by rapid degassing of the residual monomers. The polymer was recovered, after being washed with ethyl alcohol and dried at 60 ° C and 1019 x 10"5 kg / cm2 (1 Pascal) for at least 8 hours.

COMMENTS ON THE TABLES Tables 1-5 indicate the results of ethylene-propylene copolymerization tests in solvent in the presence of H2, while Tables 6 and 7 refer to ethylene-propylene co- and ter-polymerization tests -Diene the liquid propylene, made both ways, in the presence and without H2. The comparative examples refer to tests performed in the presence of V complexes with acetylacetone and chlorinated acetylacetone ligands -V (CH3-CO-CH-CO-CH3) 3 and V (CC13-C0-CH-C0-CH3) 3, known catalysts in the polymerization of EP (D) M. From the data in Table 1 it can be seen how the catalysts of the present invention (from II to V) in the presence of DEAC and ETA form a catalyst system which is analogous (as far as the catalytic activity is concerned in both ways, with respect to the Vanadium and chlorine, and the characteristics of the polymer) to that based on V (acac) 3. From the data in Table 2 it can be seen that the catalysts of the present invention (from II to V) are more active, in the presence of trialkyl Al, than both, V (acac) 3, which has no catalytic activity, and also Vtricloroacetylacetonate - V (CCl3-CO-CH-CO-CH3) 3 -, which provides an amount of polymer that is 20 times smaller. In addition, the activity of the catalysts of the present invention is not modified by the presence of the reactivator, which, on the other hand, is indispensable for becoming active to V (acac) 3 (Table 3). The molecular weights (Mw) of the polymers vary from 200 to 400,000; The MWD is generally very broad, reaching values of 11, but can be limited to values of about 3-6 in several ways: • by varying the amount of THF coordinated to V (Table 4); elongating the aliphatic chain of the chlorocarboxylic ligand (from CCl3COO- to CC13CH2CH2C00-) (Table 2, exes 9 and 12); • subjecting the V complex to aging with alkyl Al under certain conditions of temperature and Al / V ratio (Table 5). With respect to the industrial system V (acac) 3 / AlEt2Cl / ETA (example 1 - Table 1), the catalyst systems consisting of the catalysts of the present invention and Al (i-Bu) 3 demonstrate, in the tests in solution, a catalytic activity that, with respect to Vanadium, is comparable or even lower, but that with respect to chlorine is always superior (from 2 to 12 times); provide a polymer with a lower% C3 incorporated (from about 35% to 20-30% by mole), with larger molecular weights (Mw) (from about 100,000 to 400,000) and a larger MWD (from 2 to minus 4-5). The catalysts of the present invention have an analogous behavior in liquid propylene. With respect to the industrial reference system V (acac) 3 / AlEt2Cl / ETA, in fact, the catalytic system of the present invention - V (0C0CC13) 3 (THF) 2 / Al (i-Bu) 3 - demonstrates, in the liquid propylene tests (Tables 6 and 7), a catalytic activity that is comparable with respect to V, but that is greater (from 2 to 8 times) with respect to chlorine; produces a polymer with a lower% C3 incorporated (from about 50 to 20-35% by weight), with a higher% of ENB incorporated (from 3.5 to 6-7% by weight), with molecular weights (Mw) older. These pass from 700,000-1,000,000 to values > 1,000,000 (which can no longer be measured with GPC) for the polymers obtained from the tests carried out with H2, and reach values of up to 300,000 for the polymers obtained from the tests carried out in the presence of H2. Of the tests performed in the presence of H2, however, polymers are obtained with a lower yield than those obtained from tests carried out without H2, while the amount of comonomer and thermonomer incorporated remains the same. It should be noted, however, that even with a smaller amount of polymer produced, the activity with respect to chlorine remains higher than that obtained with the reference system.

Table 1 Copolymerization in Ethylene-Propylene solution: tests with AlEt2 / CCl3COOEt Table 2 Copolymerization in Ethylene-Propylene solution: trials with Trialquil Al Polymerization temperature: 50 ' Table 3 Copolymerization in Ethylene-Propylene solution: tests with Al (i-Bu) 3CC1L (Al / V = 50: 1) Table 4 Copolymerization in Ethylene-Propylene solution tests with V (CCl3COO) 3 (THF) 0-2 / Al (iBu) 3 (Al / V = 10: 1) Table 5 Copolymerization in Ethylene-Propylene solution tests with V (CCl3COO) 3 (THF) i / Al (iBu) 3 (Al / V = 50: 1) Aging was carried out by placing the V complex in contact with the alkyl Al in toluene, in the ratio shown in the Table, for 10 minutes at room temperature.

Claims (17)

RE IV INDICATIONS 1. A vanadium complex having the general formula (I):
1. (RCOO) nVXpL "(I) characterized in that R is a monofunctional hydrocarbon radical having from 1 to 20 carbon atoms, and from 1 to 6 halogen atoms, selected from chlorine and bromine; X is chlorine or bromine; L is an electron donor; p + n = 3, 4 or 5; n is greater than or equal to 1; m is between 0 and 3.
2. 2. The Vanadium complex according to claim 1, wherein R is a monofunctional hydrocarbyl radical containing from 1 to 6 chlorine atoms.
3. 3. The Vanadium complex according to claim 1, wherein X is chloro.
4. 4. The complex according to claim 1, wherein n + p = 3.
5. 5. The complex according to claim 1, wherein R-COO is wherein Ri, R2, R3, R4 and Rs / the same or different, are selected from H, Cl or Br, alkyls, cycloalkyls, aryls, arylalkys, alkylaryls or alkyls, cycloalkyls, aryls, arylalkys, alkylaryls containing chlorine or bromine , with the proviso that at least one of the residues R1-R5 is selected from chlorine or bromine, or an alkyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group containing chlorine or bromine; q varies from 0 to 10.
6. 6. The complex according to claim 1, wherein R-COO is: ; where Ri, R 2 I R, R have the meanings defined above, r and s vary independently from 0 to 5, with the restriction that r + s is less than or equal to 5.
7. 7. The complex according to claim 1, wherein R-COO is: (-) u '-COO wherein: Z, Ri, R2, R3, R, R5 and R6, the same or different, is selected from H, Cl or Br, alkyl, cycloalkyl, aryl, arylalkyl, alkylaryl or alkyl, cycloalkyl, aryl, arylalkyl, alkylaryl containing chlorine or bromine, with the proviso that at least one of the residues Z and R? -R6 is chlorine or bromine, or an alkyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group containing chlorine or bromine; t and u independently vary from 0 to 10, preferably from 0 to 2.
8. 8. The complex according to claim 1, wherein R is selected from cycloalkyl, polycycloalkyl, cycloalkenyl, polycycloalkenyl having from 3 to 20 carbon atoms, substituted with chlorine or bromine, or with hydrocarbyl group containing chlorine or bromine.
9. 9. A process for the preparation of complexes having the general formula (I), comprising: a) reaction of a thallium salt (TI) having the general formula RCOOTl, wherein R has the meaning defined above, with a Vanadium halide, preferably VC13, in an aliphatic or aromatic, ether or chlorinated hydrocarbon solvent, alone or in a mixture, preferably THF and dimethoxyethane, at temperatures in the range from 0 to 50 ° C, preferably from 15 to 30 ° C , for a time in the range from 30 minutes to 6 hours, preferably from 1 to 4 hours; b) separation, preferably filtration, of the TI halide formed by the reaction; c) Vanadium complex isolation.,
10. 10. A catalytic system for the (co) polymerization of α-olefins, which consists of: (a) Vanadium complex having the general formula (I), (b) derived from the organoaluminum having the general formula (II) AlRnXm, wherein R is an alkyl group of 1 to 20 carbon atoms, X is chlorine or bromine, preferably chlorine, and n + m = 3, with the exclusion of the compound having n = 0, (c) optionally a reactivator.
11. 11. The catalyst system according to claim 10, wherein X is chlorine.
12. 12. The catalyst system according to claim 10, wherein the reactivator (C) is a chlorinated compound.
13. 13. The catalyst system according to claim 10, wherein the Vanadium complex (I) has the general formula (la) (CC13- (-CH2-) n -COO) 3V, wherein n is between 0 and 2.
14. 14. The catalyst system according to claim 10, wherein the aluminum organ derivative (II) has the general formula A1R3, wherein R is an alkyl group of 1 to 20 carbon atoms.
15. 15. The catalytic system according to claim 14, wherein R is isobutyl.
16. 16. The catalyst system according to claim 14, wherein the reactivator is absent.
17. 17. A process for the (co) polymerization of alpha-olefins in liquid phase, at low or medium pressure, at a temperature in the range between -5 ° C to 75 ° C, characterized in that the above (co) polymerization is carried out in presence of the catalytic system according to claim 10.