MXPA98000148A - A composite of metaloc - Google Patents

Abstract

The present invention relates to the provision of a metallocene compound containing an (organo) ((omega-alkenyl) cyclopentacarbyl) silane compound attached via a bridge. Polymerization processes are also provided to produce the same

Description

A METALOCENE COMPOUND Field of the Invention In general, this invention relates to the field of metallocene compounds containing an (organo ((omega-alkenyl) cyclopentacarbyl) silane compound bonded via a bridge and to processes using the metallocene compounds containing a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) isilane attached by means of a bridge).

Background of the Invention The production of polymers that comprise ethylene is a multi-billion dollar enterprise. Many different catalysts can be used to polymerize ethylene. However, very few of these catalysts are of commercial importance. Currently, millions of dollars have been spent on research to make metallocene catalysts that are more commercially viable, and therefore more commercially important. This is because the polymers produced by such metallocene catalysts have properties that are usually not ref.26591 another unique polymer can reproduce. However, one of the technical problems associated with these metallocene catalysts is that they are homogeneous with the polymerization medium. That is, they are soluble in the medium in which the polymerization is carried out. This is a disadvantage for the use of such metallocene catalysts because the most important polymerization processes commercially use heterogeneous catalysts. Therefore, to produce more important metallocene catalysts commercially, heterogeneous metallocene catalysts must be produced. Additionally, it is very important to have a metallocene catalyst that produces polymers having a high molecular weight.

Brief Description of the Invention According to one aspect of this invention there is provided a metallocene compound containing a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) (silane attached by means of a bridge). According to another aspect of this invention there is provided a process for polymerizing monomers, especially ethylene, with a metallocene compound containing an (organ) ((omega-alkenyl) (cyclopentacarbyl) (silane bonded via a bridge This process comprises (or consists essentially of, or consists of): the use of a metallocene compound containing a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane bonded by means of a bridge, to polymerize the monomers in polymers.

Detailed description of the invention In general, metallocene compounds containing a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) (.sylan linked by means of a bridge), are those compounds having the general formula indicated in Box One.

BOX ONE GENERAL FORMULA FOR METALOCENE COMPOUNDS CONTAINING A COMPOSITE OF (ORGAN) ((0MEGA-ALKENIL) CYCLENTPENTACRIBLE) (SILAN0 UNITED BY A BRIDGE) R In this general formula, R is a group (R1) 2C = C (R1) - (C (R1) 2) n-C (R1) 2- (where n is from 0 to about 20). In this group, each R1 can be any substituent that substantially does not interfere, and does not interfere adversely, with any of the processes described herein. For example, each R1 may be hydrogen or hydrocarbyl having from 1 to about 20 carbon atoms. However, it is preferred that each R1 has from 1 to 10 carbon atoms, and it is even more preferred that each R1 has from 1 to 6 carbon atoms. Additional examples of R1 are hydrogen, alkyl, aryl, alkoxy, and aryloxy. Commonly, it is more preferred if R1 is hydrogen. The group R is attached or attached to a cyclopentacarbonyl group (R °) which can be either substituted or unsubstituted, and which can form a metallocene compound with a transition metal. The substituents of the cyclopentacarbyl group can be any substituent that does not substantially interfere, and does not interfere adversely, with any of the processes described herein. Examples of the cyclopentacarbyl groups are substituted and unsubstituted cyclopentadiene groups and unsubstituted indenyl groups. It is usually preferred that the cyclopentacarbyl group (R °) be an indenyl.

The cyclopentacarbyl group is attached to or bound to a linking group by means of a silane bridge which may be substituted or unsubstituted. The substituents (R3) of the linking group by means of a silane bridge, can be any substituents which do not substantially interfere, and which do not interfere adversely, with any of the processes described herein. Examples of such substituents are hydrogen, alkyl, aryl, alkoxy, and aryloxy. Usually, it is preferred if each R3 is alkyl or aryl, however, it is more preferred if R3 is aryl, such as, for example, phenyl. The fluorenyl group in the general formula can be substituted or unsubstituted. Substituents of the fluorenyl group can be any substituent that does not substantially interfere, and does not interfere adversely, with any of the processes described herein. Examples of such substituents are hydrogen, alkyl, aryl, alkoxy, and aryloxy. Usually, it is preferable if the substituents are hydrogen. In the general formula, M is a transition metal selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, and the lanthanides.

Usually, the preferred transition metals are zirconium and hafnium. In the general formula, X is an alkyl, aryl, alkoxy, aryloxy, amide, hydride, or halogen. Usually, it is more preferable if X is halogen. However, it is more preferable if X is chlorine. This metallocene compound containing a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane bonded via a bridge, can be produced by first taking a cyclopentacarbyl compound and reacting it with an organometallic compound such as, for example, n-butyl lithium, to form a metal cyclopentacarbyl compound. In general, the metal in the organometallic compound is any Group I metal and the organ part of the compound is an alkyl. The cyclopentacarbyl compound is any compound having at least five carbon atoms arranged or distributed in a cyclic structure. This cyclopentacarbyl compound can be either substituted or unsubstituted. Additionally, this cyclopentacarbyl compound can form a metallocene compound with a transition metal. The substituents of the cyclopentacarbyl compound can be any which does not substantially interfere, and which does not interfere adversely, with any of the processes described herein. The examples of the compounds of cyclopentacarbyl are substituted and unsubstituted cyclopentadiene groups and substituted and unsubstituted indenyl groups. In general, the reaction of the cyclopentacarbyl compound with an organometallic compound to produce a cyclopentacarbyl metal is carried out at any suitable temperature and pressure. Usually, a temperature of about -80 ° C to about 160 ° C, and a pressure of about 0 to about 100 atmospheres, are preferred. However, a temperature of about -80 ° C to about 60 ° C and a pressure of about 1 atmosphere are more preferred. The molar ratio of the cyclopentacarbyl compound to the organometallic compound can be any suitable ratio. Commonly, molar ratios of 1 to 1 are preferred. This cyclopentacarbyl metal compound is then reacted with a haloalkene to produce a (omega-alkenyl) cyclopentacarbyl compound. In general, the reaction of the cyclopentacarbyl metal compound with a haloalkene to produce a (omega-alkenyl) cyclopentacarbyl compound is carried out at any suitable temperature and pressure. Typically, a temperature of about -80 ° C to about 160 ° C and a pressure of about 0 to about 100 atmospheres are preferred. However, a temperature of about -80 ° C to about 60 ° C and a pressure of about 1 atmosphere are more preferred. The molar ratio of the cyclopentacarbyl metal compound to the haloalkene can be any suitable ratio. Habitually, molar ratios of 1 to 1 are preferred. Once the (omega-alkenyl) cyclopentacarbyl compound is produced, it can be reacted with an organosilane to produce a compound (organ) ((omega-alkenyl) cyclopentacarbyl) (linked by a silane bridge). In general, the reaction of the compound (omega-alkenyl) cyclopentacarbyl with an organosilane to produce an (organ) ((omega-alkenyl) cyclopentacarbyl) (attached by a silane bridge) is carried out at any suitable temperature and pressure . Usually, a temperature of about -80 ° C to about 160 ° C and a pressure of about 0 to about 100 atmospheres are preferred. However, a temperature of about -80 ° C to about 60 ° C and a pressure of about 1 atmosphere are more preferred. The molar ratio of the metal cyclopentacarbyl compound to the haloalkene can be any suitable ratio.

Usually, molar ratios of 1 to 1 are preferred. Once the compound (organ) ((omega-alkenyl) cyclopentacarbyl) (linked by a silane bridge) is produced, it can be used to produce metallocene compounds wherein the (omega-alkenyl) cyclopentacarbyl portion of the composed of (organ) ((omega-alkenyl) cyclopentacarbyl) (attached by a silane bridge) is one of the ligands of the metallocene compound. Several methods are known in the art for attaching a ligand to a transition metal to produce a metallocene compound. For example, the following references may be consulted: Patents of the United States of America Nos. 5,436,305; 5,498,581; 5,565,592; and European Application No. 524,624. In general, however, metallocene compounds containing an (omega-alkenyl) (cyclopentacarbyl) can be prepared by reacting the (organ) compound ((omega-alkenyl) cyclopentacarbyl) (attached by a silane bridge) with a compound of alkali metal alkyl to produce a salt of the ligand which is then reacted with a transition metal compound to give a metallocene compound. These metallocene compounds can be used to polymerize several olefins. The Particular polymerization conditions employed using these compounds may vary depending on the particular results desired. Usually, these compounds are used with organoaluminoxane compounds, such as, for example, methylaluminoxane, to form better polymerization catalysts. The ratio of the transition metal to the organoaluminoxane composition can vary widely depending on the particular composition selected and the desired results. Typically, the atomic ratio of the aluminum in the composition of the organoaluminoxane to the transition metal is in the range of about 1/1 to about 20000/1, preferably in the form of about 15/1 to about 5000/1, and more preferably in approximate form 100/1 to approximately 1000/1. Examples of some monomers for polymerization include ethylene and alpha-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-hexene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-hexadecene, cyclopentene, norborene, styrene, 4-methyl styrene, vinyl cyclohexane, butadiene, and the like and mixtures thereof same. Preferably the monomer consists of or consists essentially of ethylene. For him use of the term "consists essentially of" it is proposed that the polymerized monomer does not include any of the additional compounds which adversely affect the desired properties imparted by the ethylene to the polymer thus produced. The present invention is particularly useful in suspension type polymerizations since they allow such polymerizations to be carried out more effectively than has hitherto been possible. A particularly preferred type of suspension polymerization involves polymerization of the continuous closed cycle reactor type wherein the monomer, catalyst, and diluent, if employed, are added continuously to the reactor when necessary and the polymer product is continuously removed. or at least periodically. In general, in such processes, ethylene is polymerized in the presence of a suitable liquid diluent, a higher alpha-olefin comonomer, and optionally, hydrogen. The temperature of the polymerization can vary over a wide range which will allow suspension polymerization. Frequently the suspension polymerization will be carried out at a temperature in the range of about 50 ° C to about 100 ° C, although higher and lower temperatures can be used.

One of the benefits of this invention is that during the polymerization the metallocene compound is incorporated into the polymer chain whereby a heterogeneous metallocene catalyst is formed. As described aboveThis is an important result because it increases the commercial importance of the metallocene compounds. For example, a heterogeneous metallocene catalyst can be formed by prepolymerizing these metallocene compounds with a monomer, such as, for example, ethylene, to form a metallocene compound supported on a prepolymer. Examples of such techniques are described in U.S. Pat. No. 5,498,581. The following examples are provided to further illustrate this invention. However, the invention should not be understood to be limited to the particular embodiments in these examples.

EXAMPLES All the examples were carried out using standard Schlenk techniques with the exclusion of air and oxygen mixture under argon. The solvents were dried over either: (a) an Na / K alloy for the ether, hexane, pentane, tetrahydrofuran, and toluene; (b) P4O10 for methylene chloride; or (c) magnesium for methanol; and then distilled under argon.

EXAMPLE ONE PREPARATION OF A COMPOUND OF ((OMEGA-ALQUENIL) CICLOPENTACARBILO) EXAMPLE 1-1 Ten ml (85.7 mmoles) of indene, which is a cyclopentacarbyl compound, were added to a vessel containing 150 ml of diethyl ether and 15 ml of tetrahydrofuran to form a first mixture. This first mixture is then reacted with 53.6 ml (85.7 mmoles) of n-butyllithium (1.6 M in hexane) to form the indenyl-lithium, which is a cyclopentacarbyl metal compound. This reaction was carried out at -78 ° C. A yellow solution formed. This yellow solution is then stirred at room temperature (approximately 25 ° C) for four hours and then cooled again to -78 ° C. An equivalent amount of 1-Bromopropene, a haloalkene compound, is added dropwise to the yellow solution to form a second mixture. This second mixture is then stirred overnight at room temperature (approximately 25 ° C).

After this, this second mixture is then hydrolyzed with 50 ml of water to form an organic phase and an aqueous phase. The organic phase is dried over sodium sulfate and then the solvent is evaporated under a vacuum to produce a third mixture. This third mixture is then distilled using a high vacuum (10 ~ 2 torr) to obtain a product. The product obtained was allyl-1-indene, which is a compound of ((omega-alkenyl) cyclopentacarbyl).

EXAMPLE 1-2 Ten ml (85.7 mmoles) of the indene, which is a cyclopentacarbyl compound, are added to a vessel containing 150 ml of diethyl ether and 15 ml of tetrahydrofuran to form a first mixture. This first mixture is then reacted with 53.6 ml (85.7 mmoles) of n-butyllithium (1.6 M in hexane) to form the indenyl lithium, which is a metal cyclopentacarbyl compound. The reaction was carried out at -78 ° C. A yellow solution formed. This yellow solution is then stirred at room temperature (about 25 ° C) for four hours and then cooled again to -78 ° C. An equivalent amount of 1-bromohexene, a haloalkene compound, was added dropwise to the yellow solution to form a second mixture. This mixture is then stirred overnight at room temperature (approximately 25 ° C). After this, this second mixture is then hydrolyzed with 50 ml of water to form an organic phase and an aqueous phase. The organic phase is dried over sodium sulfate and the solvent is evaporated under a vacuum to produce a third mixture. This third mixture is then distilled using a high vacuum (10 ~ 2 torr) to obtain a product. The product obtained was 5-hexenyl-l-indene, which is a compound of ((omega-alkenyl) cyclopentacarbyl).

EXAMPLE TWO PREPARATION OF A COMPOUND OF (ORGAN) ((OMEGA-ALQUENIL) CICLOPENTACARBIL) SILANO EXAMPLE 2-1 Ten mmoles of allyl-1-indene (in 60 ml of diethyl ether) are reacted with 6.25 ml of butyllithium (1.6 M solution in hexane) to form a first mixture. The first mixture is then stirred for four hours. After stirring, 2.58 grams (10 mmol) of the (9-fluorenyl) (dimethyl) (chloro) silane, which is an organosilane, is added to the first mixture to form a second mixture. This second mixture is then stirred overnight. The second mixture is then hydrolyzed with 50 ml of water to form an aqueous phase and an organic phase. The organic phase is then dried over sodium sulfate followed by evaporation of the organic phase to leave the product, which was a yellow oil. This product was ((3-allyl) indenyl) (dimethyl) (9-fluorenyl) silane, which is a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane.

EXAMPLE 2-2 Ten mmoles of 5-hexenyl-1-indene (in 60 ml of diethyl ether) are reacted with 6.25 ml of butyllithium (1.6 M solution in hexane) to form a first mixture. This first mixture is then stirred for four hours. After stirring, 2.58 grams (10 mmol) of the (9-fluorenyl) (dimethyl) (chloro) silane, which is an organosilane, are added to the first mixture to form a second mixture. This second mixture is then stirred overnight. The second mixture is then hydrolyzed with 50 ml of water to form an aqueous phase and an organic phase. The organic phase is then dried over sodium sulfate followed by evaporation of an organic phase to leave the product, which was a yellow oil This product was ((3-hex-S-enyl) indenyl) (dimethyl) (9-fluorenyl) silane, which is a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane.

EXAMPLE 2-3 Ten mmoles of allyl-1-indene (in 60 ml of diethyl ether) are reacted with 6.25 ml of butyllithium (1.6 M solution in hexane) to form a first mixture. This first mixture is then stirred for four hours. After stirring, 3.83 grams (10 mmol) of (9-fluorenyl) (diphenyl) (chloro) silane, which is an organosilane, are added to the first mixture to form a second mixture. This second mixture is then stirred overnight. The second mixture is then hydrolyzed with 50 ml of water to form an aqueous phase and an organic phase. The organic phase is then dried over sodium sulfate followed by the concentration of the organic phase. The product is precipitated as a white powder. This product was ((3-allyl) indenyl) (diphenyl) (9-fluorenyl) silane, which is a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane.

EXAMPLE 2-4 Ten mmoles of 5-hexenyl-l-indene (in 60 ml of diethyl ether) are reacted with 6.25 ml of butyllithium (1.6 M solution in hexane) to form a first mixture. This first mixture is then stirred for four hours. After stirring, 3.83 grams (10 mmol) of the (9-fluorenyl) (diphenyl) (chloro) silane, which is an organosilane, is added to the first mixture to form a second mixture. This second mixture is then stirred overnight. The second mixture is then hydrolyzed with 50 ml of water to form an aqueous phase and an organic phase. The organic phase is then dried over sodium sulfate followed by the concentration of the organic phase. The product is precipitated as a white powder. This product was ((3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane, which is a compound of (organ) ((omega-alkenyl) cyclopentacarbyl) silane.

EXAMPLE THREE PREPARATION OF A METALOCENE COMPOUND CONTAINING A COMPOUND OF (ORGAN) ((OMEGA-ALQUENIL) CICLOPENTACARBILO) SILANO EXAMPLE 3-1 One gram of ((3-allyl) indenyl) (dimethyl) (9-fluorenyl) silane is mixed with 40 ml of diethyl ether to form a first mixture. This first mixture is stirred with 2 equivalents of n-butyllithium (1.6 M in hexane) for about eight hours at room temperature (about 25 ° C) to form a second mixture. After this, one equivalent of zirconium tetraeloride is added to the second mixture and stirred overnight to form a first product. This product was (1- (3-allyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride, a metallocene compound.

EXAMPLE 3-2 One gram of ((3-hex-5-enyl) indenyl) (dimethyl) (9-fluorenyl) silane was mixed with 40 ml of diethyl ether to form a first mixture. This first mixture is stirred with 2 equivalents of n-butyllithium (1.6 M in hexane) for about eight hours at room temperature (about 25 ° C) to form a second mixture. After this, one equivalent of zirconium tetraeloride is added to the second mixture and stirred overnight to form a first product. East second product was (1- (3-hex-5-enyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride, a metallocene compound.

EXAMPLE 3-3 One gram of ((3-allyl) indenyl) (diphenyl) (9-fluorenyl) silane is mixed with 40 ml of diethyl ether to form a first mixture. This first mixture is stirred with 2 equivalents of n-butyllithium (1.6 M in hexane) for about eight hours at room temperature (about 25 ° C) to form a second mixture. After this, an equivalent of zirconium tetraeloride is added to the second mixture and stirred overnight to form a first product. This second product was (1- (3-allyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium dichloride, a metallocene compound.

EXAMPLE 3-4 One gram of ((3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane is mixed with 40 ml of diethyl ether to form a first mixture. This first mixture is stirred with 2 equivalents of n-butyllithium (1.6 M in hexane) for approximately eight hours at room temperature (approximately 25 ° C) to form a second mixture. After this, one equivalent of zirconium tetraeloride is added to the second mixture and stirred overnight to form a first product. This second product was the dichloride of (1- (3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium, a metallocene compound.

EXAMPLE FOUR POLYMERIZATION OF ETHYLENE WITH A COMPOUND OF METALOCENE CONTAINING A COMPOSITE OF (ORGAN) ((OMEGA-ALKENIL) CICLOPENTACARBIL) SILANO EXAMPLE 4-1 Approximately 10 mg of (1- (3-allyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride is mixed with 10 ml of methylaluminoxane (30 weight percent in toluene) to form a catalyst complex and then it is diluted with 10 ml of toluene. The polymerization of ethylene is carried out in a 1-liter Buechi laboratory autoclave. The autoclave is filled with 500 ml of pentane and 7 ml of methylaluminoxane. An amount (approximately 1.8 x 10 ~ 6 moles) of the catalyst complex is then added to the autoclave. He The autoclave thermostat is then set at 60 ° C and a constant ethylene pressure of 10 bar is applied. The reactor is stirred at 800 rpm. Polymerization stops after one hour. Approximately 71 grams of polyethylene are recovered. The molecular weight of the polymer was 350,000. This average viscometric molecular weight was determined with a precision capillary viscometer in Decalin at 135 ° C. The calibration curves were available for molecular weight determination. However, the insoluble components were separated before the molecular weight measurement, therefore the determined value is not an absolute value, but it provides an indication of the molecular weight trend. All of the following molecular weights were determined using this technique.

EXAMPLE 4-2 Approximately 10 mg of (1- (3-hex-5-enyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride is mixed with 10 ml of methylaluminoxane (30 weight percent in toluene) to form a complex of the catalyst and then diluted with 10 ml of toluene.The polymerization of the ethylene was carried out in a 1-liter Buechi laboratory autoclave.The autoclave was filled with 500 ml of pentane and 7 ml of methylaluminoxane. amount (approximately 1.7 x 10"6 moles) of the catalyst complex are then added to the autoclave.The autoclave thermostat is then set at 60 ° C and a constant ethylene pressure of 10 bar was then applied.The reactor is stirred at 800 rpm Polymerization stops after one hour Approximately 45 grams of polyethylene was recovered The molecular weight of the polymer was 385,000.

EXAMPLE 4-3 Approximately 10 mg of (1- (3-allyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium dichloride was mixed with 10 moles of methylaluminoxane (30 weight percent in toluene) to form a catalyst complex and then it is diluted with 10 ml of toluene. The polymerization of ethylene is carried out in a 1-liter Buechi laboratory autoclave. The autoclave is filled with 500 ml of pentane and 7 ml of methylaluminoxane. An amount (approximately 1.5 x 10"6 moles) of the catalyst complex is then added to the autoclave.The autoclave thermostat is then set at 60 ° C and a constant ethylene pressure of 10 bar is applied.The reactor is stirred at 800 ° C. The polymerization is stopped for one hour, approximately 40 grams of polyethylene were recovered. The molecular weight of the polymer was 580,000.

EXAMPLE 4-4 Approximately 10 mg of (1- (3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium dichloride is mixed with 10 ml of methylaluminoxane (30 weight percent toluene) to form a complex of catalyst and then diluted with 10 ml of toluene. Polymerization of the ethylene was carried out in a 1-liter Buechi laboratory autoclave. The autoclave is filled with 500 ml of pentane and 7 ml of methylaluminoxane. An amount (approximately 1.5 x 10"6 moles) of the catalyst complex is then added to the autoclave.The autoclave thermostat is then set at 60 ° C and a constant ethylene pressure of 10 bar is applied.The reactor is stirred at 800 ° C. The polymerization is stopped for one hour, about 76 grams of polyethylene are recovered, the molecular weight of the polymer was 480,000.

EXAMPLE FIVE POLYMERIZATION OF ETHYLENE WITH A METALOCENE COMPOUND CONTAINING A COMPOUND OF (ORGAN) ((OMEGA-ALKENIL) CICLOPENTACARBILO) SILANO TO FORM A HETEROGENEOUS CATALYST COMPLEX EXAMPLE 5-1 In a Schlenk tube or chamber, (1- (3-allyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride is mixed with methylaluminoxane and toluene to form a catalyst complex. This catalyst complex is then exposed to an ethylene pressure of 0.4 to 0.6 bar to incorporate the catalyst complex into an ethylene polymer chain, whereby a heterogeneous metallocene catalyst is formed.

EXAMPLE 5-2 In a Schlenk tube or chamber, (1- (3-hex-5-enyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride is mixed with methylaluminoxane and toluene to form a catalyst complex. This catalyst complex is then exposed to an ethylene pressure of 0.4 to 0.6 bar to incorporate the complex of the catalyst in an ethylene polymer chain, whereby a heterogeneous metallocene catalyst is formed.

EXAMPLE 5-3 In a Schlenk tube or chamber, (1- (3-allyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium is mixed with methylaluminoxane and toluene to form a catalyst complex. This catalyst complex is then exposed to an ethylene pressure of 0.4 to 0.6 bar to incorporate the catalyst complex into an ethylene polymer chain whereby a heterogeneous metallocene catalyst is formed.

EXAMPLE 5-4 In a Schlenk tube or chamber, (1- (3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium dichloride is mixed with methylaluminoxane and toluene to form a catalyst complex. This catalyst complex is then exposed to an ethylene pressure of 0.4 to 0.6 bar to incorporate the catalyst complex into an ethylene polymer chain whereby a heterogeneous metallocene catalyst is formed.

COMPARATIVE EXAMPLE In a Schlenk tube or chamber, (9-fluorenyl) (5-hexenyl) (1-indenyl) (methyl) -silane zirconium dichloride is mixed with methylaluminoxane to form a catalyst complex. This catalyst is then exposed to an ethylene pressure of 0.4 to 0.6 bar to incorporate the catalyst complex into an ethylene polymer chain, whereby a heterogeneous metallocene catalyst is formed. The polymerization of ethylene is carried out in a 1-liter Buechi laboratory autoclave. The autoclave is filled with 500 ml of pentane and 7 ml of methylaluminoxane. An amount (approximately 1.8 x 10"6 moles) of the catalyst complex is then added to the autoclave.The autoclave thermostat is then set at 60 ° C and a constant ethylene pressure of 10 bar is applied.The reactor is stirred at 800 ° C. rpm Polymerization stops after one hour Approximately 52 grams of the polyethylene was recovered The molecular weight of the polymer was 270,000.

DESCRIPTION OF THE EXAMPLES In Examples 4-2, (1- (3-hex-5-enyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride is used to polymerize ethylene. In the comparative example, (9-fluorenyl) (5-hexenyl) (1-indenyl) (methyl) silane zirconium dichloride is used to polymerize ethylene. The main difference between these two compounds is that the first one has a hexene group in omega over indenyl, while the latter has a hexene group in. omega on the group of silane union by means of a bridge. Although this difference may seem minor for those persons who are not experienced in the art, the difference in molecular weight of the polymers produced by each catalyst is unexpected and not obvious. That is, the first compound polymerizes ethylene to form a polymer having a molecular weight 43 percent greater than the latter. In Example 4-4, (1- (3-hex-5-enyl) indenyl) (diphenyl) (9-fluorenyl) silane zirconium dichloride is used to polymerize ethylene. In Example 4-2, (1- (3-hex-5-enyl) indenyl) (dimethyl) (9-fluorenyl) silane zirconium dichloride was used to polymerize ethylene. The main difference between these two compounds is that the first has phenyl groups on the group of silane binding by means of a bridge, while the latter has methyl groups on the group of silane binding by means of a bridge. Although this difference may seem minor to those of no skill in the art, the difference in molecular weight of the polymers produced by each catalyst is unexpected and not obvious. That is, the first compound polymerizes ethylene to form a polymer having a molecular weight 25 percent greater than the latter.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims (12)

1. A metallocene compound having the following formula: R characterized in that M is a transition metal which is titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, or a lanthanide; wherein X is alkyl, aryl, alkoxy, aryloxy, amide, hydride, or halogen; wherein R is a group (R1) 2C = C (R1) - (C (R1) 2) n- (CR1) 2 and n is from 0 to about 20, and each R1 is hydrogen or a hydrocarbyl having from 1 to 20 carbon atoms; wherein R3 is hydrogen, alkyl, aryl, alkoxy, or aryloxy; and wherein R ° is a cyclopentacarbyl group.

2. A compound according to claim 1, characterized in that R1 is hydrogen, alkyl, aryl, alkoxy, or aryloxy, preferably hydrogen.

3. A compound according to claim 1 or 2, characterized in that R1 has from 1 to 10 carbon atoms, preferably from 1 to 6 carbon atoms.

4. A compound according to any of claims 1-3, characterized in that R3 is alkyl or aryl.

5. A compound according to any of the preceding claims, characterized in that R ° is a substituted or unsubstituted cyclopentadiene group, preferably a substituted or unsubstituted indenyl group.

6. A compound according to any of the preceding claims, characterized in that M is zirconium or hafnium.

7. A compound according to any of the preceding claims, characterized in that X is halogen, preferably chlorine.

8. A process for polymerizing an olefin monomer, characterized in that it comprises contacting at least one monomer under suitable polymerization conditions with a compound according to any of the preceding claims.

9. A process according to claim 8, characterized in that at least one monomer is ethylene, or ethylene and at least one olefin having 3 to 20 carbon atoms or a mixture thereof.

10. A process according to claim 8, characterized in that the olefin is propylene, l-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-methyl-1-hexene, 1-hexene, 4 -methyl-1-pentene, 1-octene, 1-hexadecene, butadiene or a mixture thereof, preferably 1-hexene.

11. A process according to claim 8, characterized in that the olefin is the cyclopentene, norborene, styrene, 4-methyl styrene, vinyl cyclohexane, or a mixture thereof.

12. A process according to claim 8, characterized in that the monomer consists, or consists essentially of, ethylene.