METALLOCENE CATALYST SUPPORTED BY HYBRID SUPPORTING MEANS, PROCESS FOR PRODUCING SAME, POLYMERIZATION PROCESS FOR PRODUCING AN ETHYLENE HOMOPOLYMER OR COPOLYMER WITH BROAD OR BIMODAL MOLAR MASS DISTRIBUTION, USE OF THE SUPPORTED METALLOCENE CATALYST AND ETHYLENE POLYMER WITH BROAD OR BIMODAL MOLAR MASS DISTRIBUTION

Abstract

The present invention describes a metallocene catalyst based on a transition metal of group 4 or 5 of the periodic table, supported on a hybrid catalytic support provided with aliphatic organic groups, and a process for supporting metallocene on the hybrid catalytic support. The supported metallocene catalyst provides an ethylene polymer with broad or bimodal molecular weight distribution, in the presence of only one metallocene complex on the support.

Claims

1. A polymerization process for preparing a homopolymer or a copolymer of ethylene with broad or bimodal molar mass distribution, wherein the polymerization reaction takes place in the presence of a supported metallocene catalyst comprising: (I) at least one metallocene derived from a compound of formula 1:
[L].sub.2-MQ.sub.2  formula (1) wherein: M is a transition metal of group 4 or 5 of the periodic table; Q, which may be equal or different, comprises: halogen radical, aryl radical, alkyl radical containing 1 to 5 carbon atoms or alkoxy radical containing from 1 to 5 carbon atoms; and L is a ligand selected from: cyclopentadienyl, indenyl or fluorenyl, optionally substituted with hydrogen, alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl or arylalkenyl, attached to the transition metal by bonding; (II) a hybrid catalytic support having at least one inorganic component and aliphatic organic groups, wherein the aliphatic organic groups are on both the surface and inside the inorganic component; and (III) at least one organometallic reactant containing a metal selected from group 2 or 13 of the periodic table.

2. Use of the supported metallocene catalyst as recited in claim 1, characterized by being in the polymerization process for obtaining ethylene homopolymer and/or ethylene copolymers with an alpha-olefin with a broad or bimodal molar mass distribution.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0055] FIG. 1—image of scanning electron microscopy of the hybrid support obtained in Example 1;

[0056] FIG. 2—image of scanning electron microscopy of the hybrid support obtained in Example 3;

[0057] FIG. 3—image of scanning electron microscopy of the hybrid support obtained in Example 4;

[0058] FIG. 4—image of scanning electron microscopy of the hybrid support obtained in Example 5;

[0059] FIG. 5—image of scanning electron microscopy of the hybrid support obtained in Example 6;

[0060] FIG. 6—GPC curve for the polyethylene prepared with the catalyst obtained in Example 8;

[0061] FIG. 7—GPC curve for the polyethylene prepared with the catalyst obtained in Example 9;

[0062] FIG. 8—GPC curve for the polyethylene prepared with the catalyst obtained in Example 7 (comparative).

DETAILED DESCRIPTION OF THE INVENTION

[0063] For a better understanding of the terms to be mentioned in the present specification, one should consider the following abbreviations and clarifications: [0064] hybrid support: a material constituted by an inorganic component and by at least one organic component; [0065] TEOS: tetraethoxylane; [0066] C contents: total percentage by mass of carbon in the hybrid catalytic support, determined by CHN on a CHN catalyst model 2400, manufactured by Perkin Elmer; [0067] Zr contents: total percentage by mass of zirconium in the supported metallocene catalyst, determined by Rutherford backscattering spectrometry on a 500 kV HVEE ion implanter; [0068] Al contents: total percentage by mass of aluminum in the supported metallocene catalyst, determined by SEM-EDX under a scanning electron microscope with energy-dispersive X-ray spectroscopy y spectrometer model JSM, manufactured by JEOL; [0069] TEAL: triethylaluminum; [0070] L.sub.2MX.sub.2: metallocene complex; [0071] Al/SiO2: ratio in weight percentage of transition metal belonging to the group 4 or 5 of the periodic table on silica, determined by Rutherford backscattering spectrometry on a 500 kV HVEE ion implanter. Al/M: mole ratio between aluminum of the co-catalyst and transition metal of the supported complex belonging to the group 4 or 5 of the periodic table; [0072] Catalytic activity: it represents the yield in kilograms (kg) of polymer produced per mole of transition metal belonging to the group 4 or 5 of the periodic table, present in the catalyst, and per hour of reaction; [0073] T.sub.m: it represents the measurement of the melting temperature in ° C. of the polymer, determined by Differential Scanning Calorimetry effected on a DSC 2920 analyzer manufactured by TA instruments; [0074] GPC: gel-permeation chromatography; [0075] M.sub.w: it represents average weight molecular mass of the polymers, determined by GPC effected on a GPCV 2000 equipment manufactured by Waters; [0076] M.sub.w/M.sub.n: it represents the molar mass distribution determined from the GPC curve effected on a GPCV 2000 Waters equipment.

[0077] The hybrid catalytic support of the present invention is constituted by an inorganic component, preferably silica, and an organic component. Said organic component is constituted by aliphatic hydrocarbons (or aliphatic organic groups) with chain containing 1 to 40 carbon atoms bonded covalently to the inorganic component. Preferably, the aliphatic hydrocarbons used in the present invention contain from 8 to 22 carbon atoms.

[0078] The hybrid catalytic support of the present invention exhibits aliphatic organic groups dispersed homogeneously at molecular level, both on the surface of the organic component and inside it.

[0079] The hybrid catalytic support of the present invention is preferably obtained by means of a sol-gel pathway. The sol-gel pathway described in the present invention refers to a hydrolytic pathway in a base medium, wherein the base acts as a catalyst of the sol-gel reaction. This base accelerates the hydrolysis reaction and condensation reaction of the reactants present in said reaction.

[0080] The hybrid catalytic support of the present invention preferably has spherical and lamellar morphology and is provided with aliphatic organic groups.

[0081] In a preferred embodiment, the process of preparing the hybrid catalytic support comprises the following steps: [0082] i) diluting an aqueous solution of a base in an alcohol; [0083] ii) adding an alcoholic solution of tetraalkylorthosilicate onto the solution obtained in steps (i); [0084] iii) reacting a solution of trialkoxydoorganosilane with the solution obtained in step (ii); and [0085] iv) removing the solvent that is present in the reaction product obtained in step (iii).

[0086] According to step (i) of the process of preparing the catalytic support of the present invention, the aqueous solution of a base with concentrations ranging from 0.1 to 5 mole/L is diluted in an alcohol.

[0087] The dilution factor (aqueous solution of a base/alcohol) ranges from 10 to 300. Preferably, one uses the dilution factor of 100.

[0088] The bases that may be used in step (i) of preparing the hybrid catalytic support are selected from hydroxides of the group I and II, aliphatic and aromatic amines, ammonium hydroxide and/or mixture thereof. Preferably, ammonium hydroxide is used. The pH of the base solution ranges from 8 to 14.

[0089] The alcohols that may be used in step (i) of preparing the hybrid catalytic support are selected from: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol and/or mixtures thereof. Preferably, ethanol is used.

[0090] The aqueous base solution and the alcohol are subjected to stirring, the stirring velocity ranging from 50 rpm to 40,000 rpm.

[0091] In step (ii) of the process of preparing the hybrid catalytic support, an alcoholic solution of tetraalkylorthosilicate is added on the solution obtained in (i).

[0092] The alcohols used in step (ii) comprise: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol and/or mixtures thereof.

[0093] Non limiting examples of the tetraalkylorthosilicates that are used in the present invention include: tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), tetrapropylorthosilicate (TPOS), tetrabutylorthosilicate (TBOS) and/or mixtures thereof. Preferably, TEOS is used.

[0094] The stirring velocity of the mixture obtained in step (ii) is kept between 50 and 40,000 rpm.

[0095] The reaction time of this mixture ranges from 0.1 to 24 hours. Preferably, 2 hours are used. This mixing and stirring step may also be carried out simultaneously in step (iii).

[0096] Step (iii) of the process of preparing the hybrid catalytic support comprises reacting a trialkoxyorganosiliane with the solution obtained in step (ii).

[0097] The trialkoxyorganosilane has carbon chain ranging from 1 to 40 carbon atoms. Preferably, a trialkoxyorganosilane with 8 to 22 carbon atoms is used.

[0098] The alkoxide grouping of said reactant should have from 1 to 4 carbon atoms. Preferably, the alkoxide grouping with 1 carbon atom is used.

[0099] Non-limiting examples of trialkoxyorganosilanes that are used in the present invention include: hexadecyltrimethoxysiliane (HDS), heptadecyltrimethoxysiliane (HPDS), octadecyltrimethoxysiliane (ODS), hexadecyltriethoxysiliane (HDES), heptadecyltriethoxysilane (HPDES), octadecyltriethoxysilane (ODES) and/or mixture thereof. Preferably, ODS is used.

[0100] The mole ratio of trialkoxyorganosilane:tetraalkylorthosilicate ranges from 1:0 to 1:100, preferably from 1:1 to 1:60.

[0101] The addition of trialkoxyorganosilane to the solution obtained in (ii) may be made concomitantly or until 24 hours after addition of tetraalkylorthosilicate. Preferably, the addition of trialkoxyorganosilane is carried out 2 hours after addition of tetraalkylorthosilicate. The reaction is kept for an additional time ranging from 0.1 to 48 h, preferably 2 hours.

[0102] The stirring velocity during the reaction should be kept between 50 and 40,000 rpm. Preferably, one uses a stirring velocity of 150 rpm. This step may be carried out simultaneously with step (ii).

[0103] In step (iv) of the process of preparing the hybrid catalytic support, one carries out the removal of the solvent that is present in the reaction product obtained in (iii).

[0104] The removal of the solvent may be carried out by evaporation at room temperature, filtration, centrifugation, or under reduced pressure. Preferably, one uses reduced pressure in a time ranging from 1 to 24 hours.

[0105] The contents of aliphatic organic groups, measured through the C content, of the hybrid catalytic support, obtained in the above-described process, range from 0.5 to 80%. The number of aliphatic organic groups in the catalytic hybrid supports influences the Mw/Mn of the ethylene polymers.

[0106] The metallocene catalyst supported in a hybrid catalytic support having aliphatic organic groups of the invention comprises: [0107] (I) at least one metallocene derived from a compound of formula 1:

[L.sub.2-MQ.sub.2  formula (1),

wherein:

[0108] M is a transition metal of the group 4 or 5 of the periodic table;

[0109] Q, which may be equal or different, comprise: halogen radical, aryl radical, alkyl radical containing 1 to 5 carbon atoms or alkoxy radical containing to 5 carbon atoms; and

[0110] L is a ligand selected from: cyclopentadienyl, indenyl or fluorenyl, either substituted with hydrogen or not, alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl or arylalkenyl, attached to the transition metal by bonding; [0111] (I) a hybrid catalytic support having at least one inorganic component and aliphatic organic groups.

[0112] Preferably, the supported metallocene catalyst comprises at least one organometallic reactant containing a metal selected from the groups 2 or 13 of the periodic table. More preferably, in the process of preparing the metallocene catalysts, one carries out impregnation of the hybrid support obtained in the preceding step (iv), with a solution of organometallic compound of group 2 or 13 of the periodic table, in an inert organic solvent.

[0113] The organometallic compounds that may be used in the step of impregnating the hybrid support are selected from: trimethylaluminum (TMAL)\, triethylaluminum (TEAL), tri-isobutylaluminum (TIBAL), tri-n-hexylaluminum (TNHAL), tri-n-octylaluminum (TNOAL), dimethylaluminum chloride (DMAC), methylaluminum dichloride (MADC), dimethylaluminum dichloride, ethylaluminum dichloride (EADC), di-isobutylaluminum chloride (DIBAC), isobutylaluminum dichloride (MONIBAC), butyl ethylmagnesium (BEM), butyl octylmagnesium (BOMAG), methyl magnesium chloride, ethylmagnesium chloride and/or mixtures thereof. These compounds may be used in the concentrated or dissolved form. In a preferred embodiment, one uses dissolved compounds in an organic solvent of the aliphatic hydrocarbon type.

[0114] When using more than one organometallic compound of the group 2 or 13 of the periodic table in the step of impregnating the hybrid support, the different compounds may be fed to the same solution or to individual solutions, either at the same time or in subsequent additions.

[0115] Non-limiting examples of inert organic solvents that may be used for solubilizing the organometallic compound of the group 2 or 13 of the periodic table are selected from: toluene, cyclohexane, n-hexane, n-heptane and n-octane and/or mixtures thereof.

[0116] In the step of impregnating the hybrid catalytic support one employs an amount of solvent sufficient to suspend the material.

[0117] The amount of organometallic compound of the group 2 or 13 of the periodic table that may be used ranges from 1 to 60% by mass of metal with respect to the mass of hybrid catalytic support. Preferably, one should use an amount ranging from 5 and 30% of metal.

[0118] The reaction time of the step of impregnating the hybrid support should range from 0.1 h to 24 h, preferably from 0.5 h to 3 h, and the reaction temperature ranges from −10° C. to 80° C., preferably from 0 to 30° C.

[0119] After impregnation, the hybrid catalytic support obtained reacts with a metallocene solution based on transition metal of groups 4 or 5 of the periodic table in an inert organic solvent.

[0120] The metallocene is derived from a compound of formula 1:

(I) [L2-MQ2  formula (1),

wherein:

[0121] M is a transition metal of the group 4 or 5 of the periodic table;

[0122] Q, which may be equal or different, comprise: halogen radical, aryl radical, alkyl radical containing 1 to 5 carbon atoms or alkoxy radical containing to 5 carbon atoms; and

[0123] L is a ligand selected from: cyclopentadienyl, indenyl or fluorenyl, either substituted with hydrogen or not, alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl or arylalkenyl, attached to the transition metal by bonding.

[0124] Representative but non-limiting examples of compounds having the formula 1 include: Cp.sub.2TiCl.sub.2, Cp.sub.2ZrCl.sub.2, Cp.sub.2HfCl.sub.2, Cp.sub.2VCl.sub.2, Cp.sub.2Ti(Me).sub.2, Cp.sub.2Zr(Me).sub.2, Cp.sub.2Hf(Me).sub.2, Cp.sub.2Ti(OMe).sub.2, Cp.sub.2Zr(OMe).sub.2, Cp.sub.2Hf(OMe).sub.2, Cp.sub.2Ti(OEt).sub.2, Cp.sub.2Zr(OEt).sub.2, Cp.sub.2Hf(OEt).sub.2, Ind.sub.2TiCl.sub.2, Ind.sub.2ZrCl.sub.2, Ind.sub.2HfCl.sub.2, Ind.sub.2VCl.sub.2, Ind.sub.2Ti(Me).sub.2, Ind.sub.2Zr(Me).sub.2, Ind.sub.2Hf(Me).sub.2, Ind.sub.2Ti(Me).sub.2, Ind.sub.2Zr(OMe).sub.2, Ind.sub.2Hf(OMe).sub.2, Ind.sub.2Ti(OEt).sub.2, Ind.sub.2Zr(OEt).sub.2, Ind.sub.2Hf(OEt).sub.2, Flu.sub.2TiCl.sub.2, Flu.sub.2ZrCl.sub.2, Flu.sub.2HfCl.sub.2, Flu.sub.2VCl.sub.2, Flu.sub.2Ti(Me).sub.2, Flu.sub.2Zr(Me).sub.2, Flu.sub.2Hf(Me).sub.2, Flu.sub.2Ti(OMe).sub.2, Flu.sub.2Zr(OMe).sub.2, Flu.sub.2Hf(OMe).sub.2, Flu.sub.2Ti(OEt).sub.2, Flu.sub.2Zr(OEt).sub.2, Flu.sub.2Hf(OEt).sub.2, (MeCp).sub.2TiCl.sub.2, (MeCp).sub.2ZrCl.sub.2, (MeCp).sub.2HfCl.sub.2, (MeCp).sub.2VCl.sub.2, (MeCp).sub.2Ti(Me).sub.2, (MeCp).sub.2Zr(Me).sub.2, (MeCp).sub.2Hf(Me).sub.2, (MeCp).sub.2Ti(OMe).sub.2, (MeCp).sub.2Zr(OMe).sub.2, (MeCp).sub.2Hf(OMe).sub.2, (MeCp).sub.2Ti(OEt).sub.2, (MeCp).sub.2Zr(OEt).sub.2, (MeCp).sub.2Hf(OEt).sub.2, (nBuCp).sub.2TiCl.sub.2, (nBuCp).sub.2ZrCl.sub.2, (nBuCp).sub.2HfCl.sub.2, (nBuCp).sub.2VCl.sub.2, (nBuCp).sub.2Ti(Me).sub.2, (nBuCp).sub.2Zr(Me).sub.2, (nBuCp).sub.2Hf(Me).sub.2, (nBuCp).sub.2Ti(OCH.sub.3).sub.2, (nBuCp).sub.2Zr(OCH.sub.3).sub.2, (nBuCp).sub.2Hf(OCH.sub.3).sub.2, (nBuCp).sub.2Ti(OEt).sub.2, (nBuCp).sub.2Zr(OEt).sub.2, (nBuCp).sub.2Hf(OEt).sub.2, (Me.sub.5Cp).sub.2TiCl.sub.2, (Me.sub.5Cp).sub.2ZrCl.sub.2, (Me.sub.5Cp).sub.2HfCl.sub.2, (Me.sub.5Cp).sub.2VCl.sub.2, (Me.sub.5Cp).sub.2Ti(Me).sub.2, (Me.sub.5Cp).sub.2Zr(Me).sub.2, (Me.sub.5Cp).sub.2Hf(Me).sub.2, (Me.sub.5Cp).sub.2Ti(OMe).sub.2, (Me.sub.5Cp).sub.2Zr(OMe).sub.2, (Me.sub.5Cp).sub.2Hf(OMe).sub.2, (Me.sub.5Cp).sub.2Ti(OEt).sub.2, (Me.sub.5Cp).sub.2Zr(OEt).sub.2, (Me.sub.5Cp).sub.2Hf(OEt).sub.2, (4,7-Me.sub.2Ind).sub.2TiCl.sub.2, (4,7-Me.sub.2Ind).sub.2ZrCl.sub.2, (4,7-Me.sub.2Ind).sub.2HfCl.sub.2, (4,7-Me.sub.2Ind).sub.2VCl.sub.2, (4,7-Me.sub.2Ind).sub.2Ti(Me).sub.2, (4,7-Me.sub.2Ind).sub.2Zr(Me).sub.2, (4,7-Me.sub.2Ind).sub.2Hf(Me).sub.2, (4,7-Me.sub.2Ind).sub.2Ti(OMe).sub.2, (4,7-Me.sub.2Ind).sub.2Zr(OMe).sub.2, (4,7-Me.sub.2Ind).sub.2Hf(OMe).sub.2, (4,7-Me.sub.2Ind).sub.2Ti(OEt).sub.2, (4,7-Me.sub.2Ind).sub.2Zr(OEt).sub.2, (4,7-Me.sub.2Ind).sub.2Hf(OCH.sub.2CH.sub.3).sub.2, (2-MeInd).sub.2TiCl.sub.2, (2-MeInd).sub.2ZrCl.sub.2, (2-MeInd).sub.2HfCl.sub.2, (2-MeInd).sub.2VCl.sub.2, (2-MeInd).sub.2Ti(Me).sub.2, (2-MeInd).sub.2Zr(Me).sub.2, (2-MeInd).sub.2Hf(Me).sub.2, (2-MeInd).sub.2Ti(OMe).sub.2, (2-MeInd).sub.2Zr(OMe).sub.2, (2-MeInd).sub.2Hf(OMe).sub.2, (2-MeInd).sub.2Ti(OEt).sub.2, (2-MeInd).sub.2Zr(OEt).sub.2, (2-MeInd).sub.2Hf(OEt).sub.2, (2-arilInd).sub.2TiCl.sub.2, (2-arilInd).sub.2ZrCl.sub.2, (2-arilInd).sub.2HfCl.sub.2, (2-arilInd).sub.2VCl.sub.2, (2-arilInd).sub.2Ti(Me).sub.2, (2-arilInd).sub.2Zr (Me).sub.2, (2-arilInd).sub.2Hf(Me).sub.2, (2-arilInd).sub.2Ti(OMe).sub.2, (2-arilInd).sub.2Zr(OMe).sub.2, (2-arilInd).sub.2Hf(OMe).sub.2, (2-arilInd).sub.2Ti(OEt).sub.2, (2-arilInd).sub.2Zr(OEt).sub.2, (2-arilInd).sub.2Hf(OEt).sub.2, (4,5,6,7-H.sub.4Ind).sub.2TiCl.sub.2, (4,5,6,7-H.sub.4Ind).sub.2ZrCl.sub.2, (4,5,6,7-H.sub.4Ind).sub.2HfCl.sub.2, (4,5,6,7-H.sub.4Ind).sub.2VCl.sub.2, (4,5,6,7-H.sub.4Ind).sub.2Ti(Me).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Zr(Me).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Hf(Me).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Ti(OMe).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Zr(OMe).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Hf(OMe).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Ti(OEt).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Zr(OEt).sub.2, (4,5,6,7-H.sub.4Ind).sub.2Hf(OEt).sub.2, (9-MeFlu).sub.2TiCl.sub.2, (9-MeFlu).sub.2ZrCl.sub.2, (9-MeFlu).sub.2HfCl.sub.2, (9-MeFlu).sub.2VCl.sub.2, (9-MeFlu).sub.2Ti(Me).sub.2, (9-MeFlu).sub.2Zr(Me).sub.2, (9-MeFlu).sub.2Hf(Me).sub.2, (9-MeFlu).sub.2Ti(OMe).sub.2, (9-MeFlu).sub.2Zr(OMe).sub.2, (9-MeFlu).sub.2Hf(OMe).sub.2, (9-MeFlu).sub.2Ti(OEt).sub.2, (9-MeFlu).sub.2Zr(OEt).sub.2, (9-MeFlu).sub.2Hf(OEt).sub.2.

[0125] Non-limiting examples of inert organic solvents that may be used for solubilizing said metallocene are: toluene, cyclohexane, n-hexane, n-heptane, n-octane and/or mixtures thereof.

[0126] One uses an amount sufficient to suspend the material.

[0127] The amount of said metallocene that may be used in the present invention ranges from 0.1 to 10% by mass of the metal with respect to the mass of the catalytic hybrid support, preferably from 0.1 to 2%. The reaction temperature should range from 0 to 60° C., preferably from 10 to 30° C. The reaction time should range from 0.1 h to 24 h, preferably from 0.5 to 4 hours.

[0128] After reacting the metallocene with the impregnated hybrid catalytic support, the solid product obtained (supported metallocene catalyst) is washed, and the solvent contained in the product is removed.

[0129] The washing of the supported metallocene catalyst obtained is carried out with a sufficient amount of organic solvent. The wash temperature may range from room temperature to 70° C. Non-limiting examples of organic solvents include: toluene, cyclohexane, n-hexane, n-heptane and n-octane.

[0130] The removal of the supported metallocene catalyst is made with reduced pressure in a time ranging from 1 to 24 h with a vacuum pump.

[0131] The contents of metal of the group 2 or 13 of the periodic table in the supported metallocene catalysts range from 1 to 60%.

[0132] The contents of metal of the group 4 or 5 of the periodic table in the supported metallocene catalysts range from 0.1 to 10%.

[0133] The supported metallocene catalysts of the present invention are suitable for being used in processes of homopolymerizing ethylene and co-polymerizing ethylene with α-olefins in suspension or gas phase processes. The a-olefins are selected from: propene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-docedene.

[0134] The supported metallocene catalysts of the present invention exhibit catalytic activity ranging from 20 to 10000 kg inch/mole M.h.

[0135] During the ethylene homopolymerization process and ethylene co-polymerization process with α-olefins, one uses, in addition to the supported complex of the present invention, an alkylaluminum co-catalyst, the preferred forms being MAO, TMAL, TEAL or TIBAL.

[0136] The molar ratio of co-catalyst/catalyst (Al/M) ion the ethylene homopolymerization and co-polymerization ranges from 500 to 2000, preferably from 1000 to 1500.

[0137] The homopolymers and copolymers obtained with the supported metallocene catalysts of the present invention exhibit a broad distribution of molar mass, comprising Mw/Mn in the range from 2 to 200 and Mw in the range from 100 to 200 kg/mole.

[0138] For a better understanding of the invention and of the improvements achieved, one presents hereinafter a few comparative examples and embodiment examples, which should not be considered limitative of the scope and reach of the invention.

[0139] In the examples of the present invention, which should not be considered limitative, TEOS (Merck, >98% purity) and octadecyltrimethoxysilane (Aldrich, 90% purity), ethanol (Merck, 99.8% purity) and ammonia solution (Dinamica, 25% ammonia), TEAL (Akzo, 10% Al), MAO (Akzo, 10% Al) and the biscyclopentadienyl zirconium IV chloride (Boulder) are used without previous purification.

[0140] Toluene (Nuclear, 98% purity) and 1-hexene (Merck), used in preparing the supported metallocene catalyst and in co-polymerizing ethylene with alpha-olefins, is dried according to the conventional techniques. All the manipulations were carried out by using inert nitrogen atmosphere with maximum limit of 1.5 ppm of humidity.

[0141] Example 1 describes the preparation of a non-hybrid silica support (comparative). Examples 2 to 6 describe the preparation of the hybrid catalytic supports with different contents of aliphatic organic groups with 18 carbon atoms. Examples 7 to 12 illustrate the synthesis of supported metallocene catalysts prepared with the supports of examples 2 to 6.

Example 1: Preparation of a (Comparative) Conventional Catalytic Support

[0142] This example illustrates the use of TEOS as an agent for preparing a non-hybrid catalytic support based on silica.

[0143] In a solution containing 200 mL ethanol and 40 mL ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL TEOS in ethanol. The suspension is left under stirring at the temperature of 25° C. for 2 h, and the resulting solid is dried, washed with ethanol and dried again in vacuum.

[0144] This component obtained was characterized, exhibiting the following characteristics:

[0145] C content:

[0146] 2.5% (w/w)—FIG. 1.

[0147] The use of TEOS without octadecyltrimethoxysilane in preparing the support results in a silica with 2.5% carbon. In this case, since the support does not have aliphatic organic groups, the organic content is attributed to the presence of residual ethoxyde groups. According to FIG. 1, this support exhibits a spherical morphology.

Example 2: Preparation of Hybrid Catalytic Support

[0148] This example illustrates the use of TEOS and octadecyltrimethoxysilane at the molar ratio of 50:1, as reactants for preparing the hybrid catalytic support having aliphatic organic groups.

[0149] In a solution containing 200 mL ethanol and 400 mL ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL TEOS in ethanol. The suspension is kept under stirring at the temperature of 25° C. for 2 h. After this period, one adds, drop by drop, 5 mL of a solution containing 0.085 mL of octadecyltrimethoxysilane in ethanol. The suspension is kept under stirring at the temperature of 25° C. for a further 2 hours, and the resulting solid is dried in vacuum, washed with ethanol and dried again in vacuum.

[0150] This component obtained was characterized, exhibiting the following characteristics:

[0151] C content: 5.1% w/w).

[0152] The carbon content obtained for this support (5.1%) is higher than that observed in the support of the comparative example (Example 1), which demonstrates the incorporation of the hydrocarbon groups of the octadecyl type (with 18 carbon atoms) in the support and, therefore, proves the formation of the hybrid support.

Example 3: Preparation of the Hybrid Catalytic Support

[0153] This example illustrates the use of TEOS and octadecyltrimethoxysilane at the molar ratio of: 20:1, as reactants for preparing the hybrid catalytic support provided with aliphatic organic groups.

[0154] In a solution containing 200 mL ethanol and 400 mL of ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL of TEOS in ethanol. The suspension is kept under stirring at the temperature of 25° C. for 2 h. After this period, one adds, drop by drop, 5 mL of a solution containing 0.21 mL of octadecyltrimethoxysilane in ethanol. The suspension is kept under stirring at the temperature of 25° C. for a further 2 h, and the resulting solid is dried in vacuum, washed with ethanol and dried again in vacuum.

[0155] This component obtained was characterized, exhibiting the following characteristics:

[0156] C content: 10.8% (w/w)—FIG. 2.

[0157] The carbon content obtained for this support (10.8%) is higher than that observed in the support of Example 2, which demonstrates a larger number of hydrocarbon groups of the octadecyl type (with 18 carbon atoms) in this support. According to FIG. 2, this support exhibits a spherical morphology with lamellar covering.

Example 4: Preparation of the Hybrid Catalytic Support

[0158] In a solution containing 200 mL ethanol and 400 mL of ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL of TEOS in ethanol. The suspension is kept under stirring at the temperature of 25° C. for 2 h. After this period, one adds, drop by drop, 5 mL of a solution containing 0.42 mL of octadecyltrimethoxysilane in ethanol. The suspension is kept under stirring at the temperature of 25° C. for a further 2 h, and the resulting solid is dried in vacuum, washed with ethanol and dried again in vacuum.

[0159] This component obtained was characterized, exhibiting the following characteristics:

[0160] C content: 19.8% (w/w)—FIG. 3.

[0161] The carbon content obtained for this support (19.8%) is higher than that observed in the support of Example 3, which demonstrates a larger number of hydrocarbon groups of the octadecyl type (with 18 carbon atoms) in the support. According to FIG. 3, this support exhibits a spherical morphology with lamellar domains.

Example 5: Preparation of the Hybrid Catalytic Support

[0162] This example illustrates the use of TEOS and octadecyltrimethoxysilane at the molar ratio of 5:1, as agents for preparing the hybrid catalytic support provided with aliphatic organic groups.

[0163] In a solution containing 200 mL ethanol and 400 mL of ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL of TEOS in ethanol. The suspension is kept under stirring at the temperature of 25° C. for 2 h. After this period, one adds, drop by drop, 5 mL of a solution containing 0.84 mL of octadecyltrimethoxysilane in ethanol. The suspension is kept under stirring at the temperature of 25° C. for a further 2 h, and the resulting solid is dried in vacuum, washed with ethanol and dried again in vacuum.

[0164] This component obtained was characterized, exhibiting the following characteristics:

[0165] C content: 37.3% (w/w)—FIG. 4.

[0166] The carbon content obtained for this support (37.3%) is higher than that observed in the support of Example 4, which demonstrates a larger number of hydrocarbon groups of the octadecyl type (with 18 carbon atoms) in this support. According to FIG. 4, this support exhibits a spherical and lamellar morphology.

Example 6: Preparation of the Hybrid Catalytic Support

[0167] This example illustrates the use of octadecyltrimethoxysilane without TEOS as a reactant for preparing the hybrid catalytic support provided with aliphatic organic groups.

[0168] In a solution containing 200 mL ethanol and 40 mL of ammonia solution, under stirring of 150 rpm, one adds 10 mL of a solution containing 2 mL of octadecyltrimethoxysilane in ethanol. The suspension is kept under stirring at the temperature of 25° C. for 2 hours, and the resulting solid is dried, washed with ethanol and dried again in vacuum.

[0169] This component obtained was characterized, exhibiting the following characteristics:

[0170] C content: 68.6% (w/w)—FIG. 5.

[0171] The carbon content obtained for this support (68.6%) is higher than that observed in the support of Example 5, which demonstrates a larger number of hydrocarbon groups of the octadecyl type (with 18 carbon atoms) in support. According to FIG. 5, this support exhibits a lamellar morphology.

[0172] Considering the results of Examples 2 to 6, the increase in the number of hydrocarbon groups of the octadecyl type in the support entails an increase in the domains with lamellar morphology and, consequently, reduction of the sphericity of the support particles.

Examples 7-12: Preparation of the Supported Metallocene Catalyst

[0173] In 50 mL of toluene, under stirring of 150 rpm, one suspends 1 g of the hybrid catalytic support obtained according to the examples described above. To the suspension one adds 2 mL of TEAL solution at a temperature of 25° C. This suspension is kept at this temperature and under stirring for 1 hour. After this period, in the same experimental conditions, one adds to the suspension 10 mL of a solution containing 32 mg of biscyclopentadienyl zirconium IV chloride in toluene. The reaction is carried out in a 2-hour period. After this period, the resulting solid is dried, washed with toluene and dried again in vacuum.

[0174] The results of contents of Al and Zr for the supported metallocene catalysts obtained with the hybrid catalytic support of Examples 1-6 are presented in Table 1.

TABLE-US-00001 TABLE 1 Results of the contents of Al and Zr for the supported metallocene catalysts obtained from the hybrid catalytic supports as described in Examples 1 to 6. Supported Content Content Hybrid Metallocene of Al of Zr catalytic support catalyst (% w/w) (% w/w) Example 1 Example 7 1.0 0.5 Example 2 Example 8 8.6 0.5 Example 3 Example 9 7.2 0.5 Example 4 Example 10 n.d. 0.2 Example 5 Example 11 1.1 0.1 Example 6 Example 12 n.d. 0.3 n.d.: Not determined.

[0175] According to Table 1, the Al content in the supported metallocene catalysts prepared with the supports of Examples 1 to 6 ranges from 1 to 9%. These results demonstrate the presence of TEAL in the composition of the supported metallocene catalysts. The Zr contents in the supported metallocene catalysts range from 0.1 to 0.5%. One observes that, for the catalysts synthesized with the supports prepared by using TEOS (Examples 7-11), the systems with higher contents of octadecyl groups exhibit content of Zr and, therefore, of immobilized metallocene complex (Examples 10 and 11). For systems with lower contents of octadecyl groups (Examples 8 and 9), there is no reduction of the contents of the immobilized metallocene complex as compared with the metallocene catalytic system prepared by using the non-hybrid support (Example 7).

Example 13: Polymerizations

[0176] In a glass reactor with 300 mL capacity and under magnetic stirring, one adds toluene in nitrogen atmosphere. The temperature is adjusted to 60° C. with the aid of a thermostatized bath. An amount of 10 mL of TEAL is added for washing the reactor. The washing time is of at least thirty minutes. The wash liquid is removed from the reactor by siphoning. After washing the reactor, one adds toluene and MAO and then the reactor is purged with ethylene. Once the purging has been carried out, the metallocene catalyst supported in a hybrid support, dissolved in toluene, is added to the reactor, forming a catalytic system with concentration of Zr of 10-6 Mole/L and with Al/Zr ratio preferably of 1500. The ethylene pressure is adjusted to 1.6 atm, and polymerization is carried out for 30 min. the resulting polymer is precipitated in acidified ethanol solution, filtered, washed with water and ethanol and dried in an oven in vacuum. For copolymerization, 15 mL of 1-hezen are added just before adding the supported metallocene catalyst.

[0177] The results of catalytic activity in the polymerization of the ethylene of the supported metallocene catalysts obtained with the hybrid catalytic supports of spherical and/or lamellar morphology are presented in Table 2.

TABLE-US-00002 TABLE 2 Catalytic activity obtained in the polymerization of the ethylene by using supported metallocene catalysts. Catalytic activity Supported metallocene catalyst (kg pol/mole Zr.h) Example 7  30 Example 8 690 Example 8* 870 Example 9 860 Example 10 310 Example 11 450 Example 12 200 *In this case, a co-polymerization of ethylene with 1-hexene was carried out.

[0178] According to Table 2, the supported metallocene catalysts prepared with the hybrid supports provided with octadecyl groups (Example 8-12) exhibit catalytic activities superior to that observed for the supported metallocene catalyst prepared by using a non-hybrid support of Example 7 (comparative).

[0179] The results of the properties of the polymers formed are presented in Table 3 below.

TABLE-US-00003 TABLE 3 Properties of the polymers obtained with supported metallocene catalyst. Supported metallocene catalyst Tm (° C.) Mw (kg/mole) Mw/Mn Example 7 132 240 2.2 Example 8 133 450 3.6 Example 8* 112 170 5.4 Example 9 133 250 6.1 Example 10 133 360 2.6 Example 11 133 580 3.5 Example 12 133 680 2.9 *In this case, a co-polymerization of ethylene with 1-hexene was carried out.

[0180] According to Table 3, the ethylene polymers produced by using the supported metallocene catalysts prepared with the hybrid supports having octadecyl groups (Examples 8-12) exhibit molar masses (Mw) higher than that observed for the ethylene polymer produced with the metallocene catalyst of Example 7 (comparative). With regard to the distribution of molar mass (Mw/Mn) of the polyethylenes, the polymers produced by using the supported metallocene catalysts prepared with the hybrid catalytic supports having octadecyl groups (Examples 8-12) have broadened values with respect to that observed for the polymer produced with the metallocene catalyst of Example 7 (comparative), which suggests better processability of the polymers prepared with the catalysts of the present invention. In addition to the broadening of the polydispersion, the polymers obtained with the supported metallocene catalysts of the present invention exhibit a bimodal molar mass distribution, as can be observed in FIGS. 6 and 7, unlike the polymer prepared with the catalyst of the comparative example (Example 7), wherein the molar mass distribution is unimodal (FIG. 8).

[0181] These results demonstrate that the broadening of the molar mass distribution of the polyethylenes is achieved by using a single type of immobilized metallocene complex in the supports and is the effect of the modification of inorganic component by the aliphatic organic groups.

[0182] Therefore, the considerations and examples of the present specification demonstrate the distinctive points of the present invention with respect to the prior art, which make the inventive process non-suggested and non-evident in the face of the literature published on the subject.

[0183] A preferred example of embodiment having been described, it should be understood that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims which include the possible equivalents.