RU2244721C2 - Polyolefin production - Google Patents

Abstract

FIELD: polymerization catalysts.

SUBSTANCE: invention describes metallocene catalytic component of catalytic system for production of polyolefin with isotactic or syndiotactic/isotactic block structure with length of monomer unit up to C₁₀, said component having general formula R"(CpR₁R₂R₃)(Cp'R₁R₂')MQ₂, where Cp represents cyclopentadienyl ring substituted by at least one substituent; Cp' is substituted fluorenyl ring; R" structural bridge imparting steric rigidity; R₁ optional substituent in cyclopentadienyl ring located at a distance to bridge and including a bulky group XR*₃ wherein X is selected from group IVA elements and R*, the same or different, are hydrogen or hydrocarbon radical containing 1 to 20 carbon atoms; R₂ optional substituent in cyclopentadienyl ring, nearest to bridge and not vicinal to remote substituent, which substituent has formula YR^# wherein Y is selected from group IVA elements and R^#, the same or different, are hydrogen or hydrocarbon radical containing 1 to 7 carbon atoms; R₃ optional substituent in cyclopentadienyl ring, nearest to bridge and being hydrogen or having formula ZR^$ wherein Z is selected from group IVA elements and R^s, the same or different, are hydrogen or hydrocarbon radical containing 1 to 7 carbon atoms; R₁' and R₂' are independent substituents in fluorenyl ring, one of them having formula AR₃’’’ wherein A is selected from group IVA elements and each of R’’’ represents independently hydrogen or hydrocarbon radical containing 1 to 20 carbon atoms and the other being hydrogen or second group AR₃’’’; M is transition metal from group IVB or vanadium and each Q is either hydrocarbon radical with 1-20 carbon atoms or halogen.

EFFECT: enabled preparation isotactic or syndiotactic/isotactic block polymer with length of monomer unit up to C₁₀.

30 cl, 13 dwg, 2 tbl, 10 ex

Description

This invention relates to a metallocene catalyst component for use in the preparation of polyolefins, especially polypropylenes. The invention further relates to a catalyst system that includes a metallocene catalyst component and a method for producing such polyolefins.

Olefins having 3 or more carbon atoms can be polymerized to produce a polymer with an isotactic stereochemical configuration. For example, in the polymerization of propylene to produce polypropylene, an isotactic structure is usually described as a structure in which methyl groups connected to tertiary carbon atoms of successive monomer units are located on one side of a hypothetical plane in which the polymer main chain lies. This can be represented using the Fisher projection as follows:

Another way to describe the structure is a method using NMR spectroscopy. The Beauvais NMR nomenclature for the isotactic pentad looks like ... mmmm, where each “m” represents a “meso” dyad or successive methyl groups located in the plane on one side.

In contrast to the isotactic structure, syndiotactic polymers are polymers in which methyl groups connected to tertiary carbon atoms of successive monomeric chain units are alternately on opposite sides of the plane. The structure of the syndiotactic polymer can be represented using the Fisher projection as follows:

In the NMR nomenclature, the syndiotactic pentad is described as ... rrrr ..., where “g” is the “racemic” dyad in which the methyl groups following each other lie alternately on opposite sides of the plane.

In contrast to isotactic and syndiotactic polymers, atactic polymers do not have a regular order of repeating units. In contrast to syndiotactic and isotactic polymers, an atactic polymer is not crystalline and forms a substantially waxy product.

Although it is possible for the catalyst to produce all three types of polymers, it is desirable that the catalyst produce mainly an isotactic or syndiotactic polymer and very little atactic polymer. In the preparation of polyolefins, the use of C2-symmetric metallocene catalysts is known. For example, C2-symmetric zirconocenes of the bis-indenyl type are known by which high molecular weight isotactic polypropylene with a high melting point can be obtained. However, the preparation of this metallocene catalyst is expensive and time consuming. More significantly, the resulting catalyst consists of a mixture of racemic and meso-isomers and often in undesirable proportions. Meso stereoisomers must be separated to avoid the formation of atactic polypropylene during the polymerization reaction.

EP-A-0426644 describes syndiotactic copolymers of olefins, such as propylene, which can be prepared using isopropyl (fluorenyl) (cyclopentadienyl) zirconium dichloride as a catalyst. It was found that syndiotacticity, measured as the amount of syndiotactic pentad rrrr, is 73-80%.

EP 747406 describes the polymerization of olefin monomers to form a syndiotactic / isotactic block polyolefin, in particular block polypropylene. The component of the polymerization catalyst was 3-trimethylsilyl-cyclopentadienyl-9-fluorenylzirconium or hafnium dichloride having an isopropylidene or diphenylmethylidene bridge.

EP-A-0537130 describes the use of C1-symmetric metallocene catalysts to produce isotactic polypropylene. The preferred catalyst in this case is isopropylidene (3-tert-butylcyclopentadienyl fluorenyl) ZrCl ₂ . This catalyst has a bulky tert-butyl group located remotely in the cyclopentadienyl ring with respect to the isopropylidene bridge. This catalyst has the advantage that it has only one stereoisomer and, therefore, it is not necessary to separate the isomeric metallocenes at the final stage of synthesis. Although the synthesis of polypropylene using this catalyst produces isotactic polypropylene, the polymer product has poor mechanical properties due to the presence of regiodefects and relatively low molecular weight.

Regiodefects occur in the polymer chain when, instead of the ideal isotactic polyolefin, in which each monomer unit is placed “head to tail” with respect to the next, an improper introduction of monomers occurs, giving a defect either of the “head to head” type or the “tail to tail” type " These so-called (2-1) regiodefects partially pass into the so-called (1-3) insertion by the isomerization process, which leads to the appearance of units of four CH ₂ groups in the main polypropylene chain. This has an adverse effect on the physical and mechanical properties of the polymer and results in low molecular weight isotactic polypropylene with a low melting point. In EP-A-0881236, this problem is solved by including isopropylidene- (5-methyl-3-tert-butylcyclopentadienylfluorene) zirconium dichloride as a component of the polymerization catalyst. Nevertheless, the molecular weights of polypropylenes obtained using this catalyst were in the range from 213900 to 458500, and the microtactivity characterized by mmmm pentad was in the range from 82.8% to 86.8%. The melting point of these polymers was in the range from 139.3 to 143.8.

EP-A-577581 describes the preparation of syndiotactic polypropylenes using metallocene catalysts having fluorenyl groups substituted at positions 2 and 7 and an unsubstituted cyclopentadienyl ring. The preparation of isotactic or syndiotactic / isotactic block polyolefins using these metallocene catalysts is not described.

EP-A-0748824 describes the use of a chiral compound of a transition metal and alumoxane to produce stereoregular isotactic polypropylenes, which are reported to have an isotactic pentad content of up to 0.972. Relative to the quantitative characteristics of the incorrect entry of monomers in the polypropylene chain, data are not presented.

The purpose of this invention is to eliminate the disadvantages inherent in the prior art.

In a first aspect, the invention provides the use of a metallocene catalyst component for producing a polyolefin comprising an isotactic or syndiotactic / isotactic polyolefin block structure with a monomer length of up to C ₁₀ , said component having the general formula

where Cp is a cyclopentadienyl ring substituted with at least one substituent; Cp 'is a substituted fluorenyl ring; R "is the structural bridge imparting stereochemical rigidity to the component; R ₁ is optionally a substituent in the cyclopentadienyl ring located remotely (distally) with respect to the bridge, said remote substituent including a volume group XR $\genfrac{}{}{0ex}{}{\text{*}}{\text{3}}$ where X is selected from the IVA group of the periodic table, and R ^* are the same or different and selected from hydrogen or a hydrocarbon radical containing from 1 to 20 carbon atoms; R ₂ is possibly a substituent in the cyclopentadienyl ring, closest (proximal) to the bridge and not vicinal to the remote substituent, having the formula YR $\genfrac{}{}{0ex}{}{\text{\#}}{\text{3}}$ where Y is selected from the IVA group of the periodic table, and R ^# are the same or different and selected from hydrogen or a hydrocarbon radical containing from 1 to 7 carbon atoms; R ₃ is possibly a substituent in the cyclopentadienyl ring closest to the bridge and is either hydrogen or has the formula ZR $\genfrac{}{}{0ex}{}{\text{\$}}{\text{3}}$ where Z is selected from the IVA group of the periodic table, and R ^$ are the same or different and selected from hydrogen or a hydrocarbon radical containing from 1 to 7 carbon atoms; R ₁ ′ and R ₂ ′ are independent substituent groups on the fluorenyl ring, one of which has the formula AR ″ ₃ , where A is selected from the IVA group of the periodic table and each R ″ ″ independently represents hydrogen or a hydrocarbon radical containing from 1 to 20 carbon atoms, and the other of them is either hydrogen or the second group AR ″ ₃ ; M is a transition metal of the IVB group of the periodic table or vanadium; and each Q is either a hydrocarbon radical containing from 1 to 20 carbon atoms, or halogen.

It was unexpectedly found that the polyolefins obtained using the proposed metallocene catalyst have very good microtacticity, especially according to the results of determining the levels of pentad distribution by ¹³ C NMR. It has also been found that polyolefins are substantially free of regiodefects. Accordingly, the polyolefins thus obtained have improved mechanical properties, including a high mass-average molecular weight, usually more than 500,000, and a melting point increased by at least 10 ° C compared with previously known values.

Applicants have unexpectedly discovered that if the fluorenyl ring in the metallocene catalyst has substituents in certain specific positions, preferably in position 3 and / or 6, the tact characteristics of the resulting polymer are significantly improved and there is a sharp decrease in the number of regiodefects in the specified polymer.

In accordance with this invention, the fluorenyl ring may be substituted by radicals with the general formula AR ″ ₃ , where A is preferably carbon or silicon, more preferably silicon. If A is carbon, then AR ″ can be a hydrocarbon radical selected from alkyl, aryl, alkenyl, alkylaryl or arylalkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl nonyl, decyl, cetyl or phenyl. If A is silicon, then AR ″ ₃ may be Si (CH ₃ ) ₃ . Preferably, at least one of R ₁ ′ and R ₂ ′ is mpem-butyl. More preferably, R ₁ ′ and R ₂ ′ are the same.

In addition, the applicants also found that if we use the proposed catalysts in the production of polypropylenes, the melting points of the latter usually exceed 150 ° C and can even reach 165 ° C, which is much better than previously achieved results.

The R "structural bridge is preferably alkylidene having 1 to 20 aliphatic or aromatic carbon atoms, dialkyl germanium, or silicon, or siloxane, alkylphosphine or an amine linking the two Cp rings with a bridging bond. Preferably, R" is isopropylidene and two Cp rings were attached at position 2 of isopropylidene. In an alternative embodiment, R "represents diphenylmethylidene.

M is preferably zirconium or titanium, most preferably zirconium. Q may be a hydrocarbon radical, such as alkyl, aryl, alkenyl, alkylaryl or arylalkyl, preferably methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, decyl, cetyl or phenyl. Preferably, Q is halogen.

The choice of the substitution structure of the cyclopentadienyl ring depends on the stereochemistry of the polyolefin product to be obtained. The proposed metallocene catalyst component can be used to produce isotactic polyolefins or syndiotactic / isotactic block polyolefins. Polyolefins can be homopolymers or copolymers. If it is necessary to obtain a syndiotactic / isotactic polyolefin, it is preferable that the cyclopentadienyl ring be replaced at a position remote (distal) with respect to the bridge. In this case, R ₁ is not hydrogen, but a substituent in the cyclopentadienyl ring. Preferably, R ₁ is a bulky remote substituent group.

In a bulky remote substituent group, R ₁ X is preferably C or Si. R ^* may be a hydrocarbon radical, such as alkyl, aryl, alkenyl, alkylaryl or arylalkyl, preferably methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, decyl, cetyl or phenyl. R ₁ may include a hydrocarbon radical that is attached to one carbon atom in the cyclopentadienyl ring or may be attached to two carbon atoms in this ring. Preferably, R ₁ is C (CH ₃ ) ₃ , C (CH ₃ ) ₂ Ph, CPh ₃ or Si (CH ₃ ) ₃ . most preferably C (CH ₃ ) ₃ .

If it is necessary to obtain an isotactic polyolefin, it is preferred that R ₁ and R _{2 are} not hydrogen, R ₂ is a substituent on the cyclopentadienyl ring closest to the bridge and preferably includes a CH ₃ group.

The cyclopentadienyl ring may also have a substituent R ₃ upon receipt of an isotactic polyolefin. Preferably, R ₃ was CH ₃ .

In another aspect, a metallocene catalyst component for use in the preparation of polyolefins includes (i) the catalyst component described above; and (ii) its regioisomer in which R ₂ is the closest (proximal) to the bridge and vicinal to the remote (distal) substituent.

Such regioisomers are often relatively easy to obtain, because they are formed as by-products during synthesis, with which you can get the component (i) of the catalyst.

It has been unexpectedly discovered that catalytic components, including both regioisomers, can be used in the preparation of polyolefins that have a multimodal, especially bimodal, molecular weight distribution.

In a further aspect, the catalyst system is used to produce polyolefins, the system comprising (a) the catalyst component described above; and (b) an aluminum or boron-containing cocatalyst capable of activating a catalyst component. Suitable aluminum-containing cocatalysts include aluminoxane, alkylaluminum and / or Lewis acid.

Alumoxanes that can be used in the proposed method are well known and preferably include oligomeric linear and / or cyclic alkylaluminoxanes described by the following formula:

where n = 1-40, preferably 10-20, m = 3-40, preferably 3-20, and R is an alkyl group containing from 1 to 8 carbon atoms, preferably methyl. Typically, upon receipt of aluminoxanes, for example, from trimethylaluminum and water, a mixture of linear and cyclic compounds is obtained.

Suitable boron-containing cocatalysts may include triphenylcarbenium borate, such as tetrakis-pentafluorophenyl-borate-triphenylcarbenium, as described in EP-A-0427696, or compounds of the general formula [L'-H] ⁺ [B Ar1 Ar2 X3 X4] ^- as described in EP-A-0277004 (p. 6, line 30-p. 7, line 7).

The catalyst system can be used in a solution polymerization process occurring in a homogeneous medium, or in a suspension method proceeding in a heterogeneous medium. In the case of a solution process, typical solvents include hydrocarbons with 4-7 carbon atoms, such as heptane, toluene or cyclohexane. In the case of a suspension process, it is necessary to immobilize the catalyst system on an inert carrier, in particular on a porous solid carrier such as talc, inorganic oxides and polymeric carrier materials such as polyolefins. The carrier material is preferably an inorganic oxide in finely divided form.

Suitable inorganic oxides to be used in accordance with the invention include metal oxides of the elements of groups 2A, 3A, 4A or 4B of the periodic table, such as silica, alumina and mixtures thereof. Other inorganic oxides that can be used individually or in combination with silica or alumina are oxides of magnesium, titanium, zirconium, etc. However, other suitable carrier materials can be used, for example, finely divided polyolefins with functional groups, such as finely divided polyethylene.

Preferably, the carrier is silica having a surface area of 200 to 700 m ² / g and a pore volume of 0.5 to 3 ml / g.

The amount of alumoxanes and metallocenes that are practically used in the preparation of a solid supported catalyst can vary widely. Preferably, the ratio of the number of moles of aluminum to the number of moles of transition metal is in the range from 1: 1 to 100: 1, more preferably in the range from 5: 1 to 50: 1.

The order of addition of metallocenes and aluminoxane to the carrier material may be different. According to a preferred embodiment of the invention, alumoxane dissolved in a suitable inert hydrocarbon solvent is added to a carrier material suspended in the same or another suitable hydrocarbon liquid, and then a mixture containing a metallocene catalyst component is added to the suspension.

Preferred solvents include mineral oils and various hydrocarbons, which are in a liquid state at the reaction temperature and do not react with individual components. Illustrative examples of suitable solvents include alkanes such as pentane, isopentane, hexane, heptane, octane and nonane; cycloalkanes such as cyclopentane and cyclohexane; and aromatic compounds such as benzene, toluene, ethylbenzene and diethylbenzene.

Preferably, the carrier material is suspended in toluene and that the metallocene and alumoxane are dissolved in toluene before being added to the carrier material.

In a further aspect, the present invention provides the use of a catalyst component described above and a cocatalyst that activates a catalyst component to produce polyolefins, preferably polypropylenes. Although the present invention is devoted to the use of metallocene catalysts whose fluorenyl ring is preferably substituted at positions 3 and / or 6, it has been observed that the use of a metallocene catalyst component comprising (i) a catalyst component and (ii) its regioisomer in which R ₂ is the closest ( proximal) with respect to the bridge and vicinal with respect to the remote (distal) substituent, preferably for the production of polyolefins, especially polypropylenes, having a multimodal molecular weight its distribution, preferably a bimodal molecular weight distribution.

In a further aspect, the invention provides a process for producing polyolefins, especially polypropylenes, which comprises reacting the above catalyst system with at least one olefin, preferably propylene, in a reaction zone under polymerization conditions.

The catalytic component can be obtained using any known method. Typically, the preparation of a catalytic component includes the preparation and isolation of bicyclic dicyclopentadiene, which is then reacted with a metal halogen to form a bridged metallocene catalyst.

In one embodiment, a method for producing a bridged metallocene catalyst comprises contacting cyclopentadiene with substituted fluorene under reaction conditions sufficient to form bridged dicyclopentadiene. The method further includes contacting the substituted bicyclic dicyclopentadiene and a metal compound having the formula MQ _k as described above under sufficient reaction conditions for the bicyclic dicyclopentadiene to enter the complexation reaction to form a bridged metallocene, where M and Q are defined as indicated above, and 0≤k≤4. A process step in which substituted bicyclic dicyclopentadiene is contacted with a metal compound can be carried out in a chlorinated solvent.

In a further embodiment of the invention, the method comprises contacting cyclopentadiene with an alkylsilyl chloride having the formula R $\genfrac{}{}{0ex}{}{\text{~}}{\text{2}}$ SiHal ₂ , where R ^{~ is a} hydrocarbon radical having from 1 to 20 carbon atoms, and Hal is a halogen. To obtain a cyclopentadienyl substituted fluorenyl ligand having a bridged silicon bond, a second equivalent of substituted fluorene is added. The subsequent steps for preparing the substituted bridged cyclopentadienyl fluorenyl ligand coordinated with metals such as Zr, Hf and Ti are similar to the steps described above.

In a further embodiment of the invention, the method comprises contacting a substituted cyclopentadiene with a fulvene forming agent, such as acetone, to produce substituted fulven. Then, in the second stage, fulven is reacted with fluorene substituted at positions 3 and / or 6, and preferably 3 and 6, with the formation of a substituted cyclopentadienyl-fluorenyl ligand having a carbon bridge bond, from which, after reaction with MCl ₄ , where M -Zr, Hf or Ti, the desired metallocene catalyst is obtained.

In a further aspect, the present invention provides an isotactic polyolefin having a monomer unit length of up to C ₁₀ and a pentad distribution comprising more than 80%, preferably at least 87% mmmm, measured by ¹³ C NMR. Preferably, the pentad distribution contains at least 90%, more preferably at least 95% mmmm, according to ¹³ C NMR results. Preferably, the amount of 2-1 and 1-3 types of incorporation of monomers into the polyolefin chain is less than 0.5%, more preferably less than 0.2, and most preferably not detected by the usual ¹³ C NMR method.

The invention will be explained below in more detail only by way of example, with reference to the accompanying drawings, in which:

1-12 shows the structures of the proposed preferred catalysts and

on Fig shows the results of the analysis of isotactic polypropylene obtained at 40 ° C using the catalyst depicted in figure 1, the method of differential scanning calorimetry.

Example 1

Preparation of isopropylidene - [(3-tert-butyl-5-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride.

A. Preparation of 3,6,6-trimethyl fulvene

Reaction:

Methodology:

In a round bottom flask equipped with a magnetic stirrer and an inlet for N ₂ , 350 ml of methanol (at -78 ° C) containing freshly prepared methylcyclopentadiene were placed under N ₂ . To this solution was added dropwise a solution of 28.6 g (0.493 mol) of acetone in methanol. Then 52.5 g (0.738 mol) of pyrolidene are added. The reaction mixture was stirred at room temperature for 24 hours. After neutralization with acetic acid and separation of the organic phase, the solvent is evaporated, the remaining yellow oil is distilled. A mixture of 3,6,6-Me ₃ -Ful and 2,6,6-Me ₃ -Ful was obtained in 65% yield.

B. Preparation of 2-methyl-3-tert-butylcyclopentadiene.

Reaction:

Methodology:

50 g (0.417 mol) of 3,6,6-Me ₃ -Ful are placed in a 1 L flask, dissolved in 500 ml of diethyl ether and cooled to 0 ° C. 260.4 ml (0.417 mol) of methyl lithium in ether (1.6 mol) was added dropwise to the solution. The reaction takes several hours. After adding 75 ml of a saturated solution of NH ₄ Cl in water, the organic phase is separated and dried with MgSO ₄ . Evaporation of the solvent gives off a yellow oil. After distillation, 33.65 g (59.28%) of 1-Me-3-t-Bu-Cp are obtained.

C. Preparation of 1,6,6-trimethyl-3-tert-butyl fulvene.

Reaction:

Methodology:

30 g (0.220 mol) of 1-Me-3-t-Bu-Cp was placed in a 1 L flask and dissolved in 60 ml of methanol. The mixture is cooled to -78 ° C. 5.11 g (0.088 mol) of acetone in 20 ml of methanol are slowly added. In the next step, 9.4 g (0.132 mol) of pyrolidene in 20 ml of methanol are added. After a week, the reaction is completed by adding 20 ml of acetic acid. After separation of the organic phase, drying, evaporation of the solvents and distillation, 16.95 g of an orange oil is obtained (43.66% yield).

D. Preparation of 2,2 - [(3-tert-butyl-5-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane.

Reaction:

Методика:

Methodology:

1.5 g (5.387 mmol) of 3,6-dt-Bu-Flu in 100 ml of dry tetrahydrofuran was placed in a 250 ml flask under N ₂ atmosphere and the solution was pre-cooled to 0 ° C. 3,6-dt-Bu-Flu can be synthesized according to the methodology of Shoji Kajigaeshi et al. (Bull. Chem. Soc. Jpn. 59, 97-103 (1986)) or M. Bruch et al. (Liebigs Ann. Chem 1976, 74-88). Then, a solution of 3.4 ml (5.387 mmol) of methyl lithium is added dropwise to the solution. The solution turns red, then it is left at room temperature for 4 hours. Then, 0.9497 g (5.382 mmol) of 1,6,6-Me ₃ -3-t-Bu-Ful in 10 ml of dry tetrahydrofuran is added dropwise to this solution. Next, the reaction is carried out for 24 hours. After adding 40 ml of a saturated solution of NH ₄ Cl in water, the yellow organic phase was separated and dried with anhydrous MgSO ₄ . Evaporation of the solvent gave 2.36 g of a solid orange product (96.32% yield).

E. Preparation of isopropylidene [(3-tert-butyl-5-methyl-cyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride (1)

Reaction:

Methodology:

2 g (4.398 mmol) of the ligand are dissolved in 100 ml of dry tetrahydrofuran in an atmosphere of N ₂ and the solution is pre-cooled to 0 ° C. A solution of 5.5 ml (8.796 mmol) of methyl lithium (1.6 mol / diethyl ether) was added dropwise to this solution. After 3 hours, the solvent was distilled off in vacuo, the red powder was washed with 2 × 100 ml of pentane. The red ligand dianion and 100 ml of pentane are placed in a flask of 250 ml in an atmosphere of N ₂ . To this suspension was added 1.02 g (4.398 mmol) of zirconium tetrachloride. The reaction mixture acquires a red-brown color, it is stirred overnight in a protective glove box. After filtering, the orange solution was distilled in vacuo at 40 ° C to obtain 2.3 g (85.18%) of an orange powder. Obviously, this metallocene is soluble in pentane. In accordance with the results of ¹ H NMR analysis of this product, it seems that as the second product, the second isomer with the chemical structure isopropylidene (2 (or 4) methyl-3-tert-butylcyclopentadienyl-3,6-di-tert-butylfluorenyl) is obtained ZrCl ₂ (2), and it has less stereoregularity.

Example 2

Preparation of isopropylidene - [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride.

The same synthesis procedure was used as in Example 1, except that the ligand in step D was replaced with 2,2 - [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane.

A. Preparation of 2,2 - [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane

Methodology:

The procedure for obtaining this ligand is the same as in stage D, but 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 0.6475 g (5.387 mmol) of 3,6,6-trimethyl fulvene (the synthesis procedure is described in Example 1, step A).

Example 3

Preparation of isopropylidene - [(3-tert-butylmethylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride.

The same synthesis procedure was used as in Example 1, except that the ligand in step D was replaced with 2,2 - [(3-tert-butylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane, obtained as follows.

A. Preparation of 2.2 - [(3-di-tert-butylcyclopentadienyl) - (3, 6-di-tert-butylfluorenyl)] propane

Methodology:

The procedure for preparing this ligand is the same as that in Step D, but 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 0.8742 g (5.387 mmol) of 6,6-dimethyl-3-tert-butyl fulvene.

B. Preparation of 6,6-dimethyl-3-tert-butidofulven

Methodology:

The synthetic procedure described in Example 1, step A, is followed, but methyl cyclopentadiene is replaced with tert-butyl cyclopentadiene.

C. Preparation of tert-butylcyclopentadiene

Methodology:

The synthetic procedure described in Example 1, step B, is followed, but 3,6,6-trimethyl fulvene is replaced by 6,6-dimethylfulven.

Example 4a

Preparation of isopropylidene - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride.

The synthesis procedure described in Example 1 was followed, except that the ligand in step D was replaced with diphenyl [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methylene.

A. Preparation of 2,2 - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step D, except that 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 1.2407 g (5.387 mmol) of 6,6-dimethyl fulvene.

B. Preparation of 2,2 - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane

Reaction:

Methodology:

First, 10 g (0.026 mol) of 2,2- (cyclopentadienyl) - (3,6-di-tert-butylfluorenyl) propane in 300 ml of tetrahydrofuran are dissolved in a 1 L flask in an atmosphere of N ₂ . Then, 16.25 ml (0.026 mol) of methyl lithium was added dropwise to this solution at room temperature (the flask was previously cooled in a water bath). After stirring for 1 hour, 3.3 ml (0.026 mol) of chlorotrimethylsilane was added to this solution. The reaction mixture was further stirred for another 3 hours. Then the solvent is distilled off in vacuo. To the solid orange residue was added 1 L of pentane. The reaction mixture is heated at 40 ° C. for 10 minutes. The orange solution was filtered (to remove LiCl, 1.40 g of residue), concentrated to 100 ml and cooled to crystallize the product -2,2- (3-trimethylsilylcyclopentadienyl) (3,6-di-tert-butylfluorenyl) propane. The raw product is beige. The crystallized product has a white color, the yield is 65-70%. The product is stored in an atmosphere of N ₂ .

Example 4b

Preparation of diphenylmethylidene - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride.

The synthesis procedure described in Example 1 was followed, except that the ligand in step D was replaced with diphenyl [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methylene.

A. Preparation of 1,1,1,1-diphenyl [(3-trimethylsilyl-cyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step D, except that 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 1.2407 g (5.387 mmol) of 6,6-dimethyl fulvene.

B. Preparation of 2,2 - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methane

Reaction:

Methodology:

First, 10 g (0.026 mol) of 2,2- (cyclopentadienyl) - (3,6-di-tert-butylfluorenyl) propane in 300 ml of tetrahydrofuran are dissolved in a 1 L flask in an atmosphere of N ₂ . Then, 16.25 ml (0.026 mol) of methyl lithium was added dropwise to this solution at room temperature (the flask was previously cooled in a water bath). After stirring for 1 hour, 3.3 ml (0.026 mol) of chlorotrimethylsilane was added to this solution. The reaction mixture was further stirred for another 3 hours. Then the solvent is distilled off in vacuo. To the solid orange residue was added 1 L of pentane. The reaction mixture is heated at 40 ° C. for 10 minutes. The orange solution was filtered (to remove LiCl, 1.40 g of residue), concentrated to 100 ml and cooled to crystallize the product -2,2- (3-trimethylsilylcyclopentadienyl) (3,6-di-tert-butylfluorenyl) propane. The raw product is beige. The crystallized product has a white color, the yield is 65-70%. The product is stored in an atmosphere of N ₂ .

Example 5

Preparation of isopropylidene - [(3,5-dimethylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl) [zirconium dichloride

The synthesis procedure described in Example 1 was followed, except that the ligand in step D was replaced with 2,2 - [(3,5-dimethylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane.

A. Preparation of 2,2 - [(3,5-dimethylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step D, but 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 0.8742 g (5.387 mmol) of 1,3,6,6-tetramethyl fulvene.

B. Preparation of 1,3,6,6-tetramethyl fulvene

Methodology:

The synthetic procedure described in Example 1, step A, is followed, but methyl cyclopentadiene is replaced by 1,3-dimethylcyclopentadiene.

C. Preparation of 1,3-dimethylcyclopentadiene

Reaction:

Methodology:

Into a 2 L flask were placed 195 ml (0.585 mol) of methyl magnesium bromide (3.0 M solution in diethyl ether) in 200 ml of dry diethyl ether in N ₂ atmosphere and the solution was pre-cooled to 0 ° C. Then, a solution of 47.15 g (0.4905 mmol) of 3-methicyclopentenone in 100 ml of diethyl ether was added dropwise to this solution for 3 hours at 0 ° C and for 1 hour at 10 ° C. The product is transferred to a 5 L flask pre-cooled to 0 ° C and containing 1 L of water. The solution is yellow in color. The yellow organic phase is separated, the solvent is removed in vacuo (500 mbar) at room temperature. Evaporation of the solvent gives off a clear orange solution. After distillation, 31.83 g of 1,3-dimethylcyclopentadiene are obtained (yield 65.95%). The product is a colorless, unstable liquid, which is immediately used to produce 1,3,6,6-tetramethylfulvene.

Example 6

Preparation of Diphenylmethylidene - [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride

The synthesis procedure described in Example 1 was followed, except that the ligand in step D was replaced with 2,2-diphenyl [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane.

A. Preparation of 1,1,1,1-diphenyl [(3-methylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step D, except that 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 1.2407 g (5.387 mmol) 3-methyl-6, 6-diphenyl fulvene.

B. Preparation of 3-methyl-6,6-diphenylfulvene

Methodology:

The procedure for preparing this fulven is the same as in Example 1, step A, except that acetone is replaced with 1.3162 g (5.387 mmol) of 6,6-diphenylfulvene.

Example 7

Preparation of Diphenylmethylidene - [(3-tert-butylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride

The synthetic procedure described in Example 1 is followed, except that the ligand in step D is replaced with diphenyl [(3-tert-butylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methylene.

A. Preparation of 1,1,1,1-diphenyl [(3-tert-butylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step A, except that 6,6-dimethyl-3-tert-butyl fulvene is replaced with 3-tert-butyl-6,6-diphenylfulven.

B. Preparation of 3-tert-butyl-6,6-diphenylfulvene

Methodology:

The procedure for obtaining this ligand is the same as in Example 1, step A, except that acetone is replaced by benzophenone and methylcycopopentadiene is replaced by mpem-butylcyclopentadiene (the synthesis procedure is described in example 4, step C).

Example 8

Preparation of Diphenylmethylidene - [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] zirconium dichloride

The synthesis procedure described in Example 1 was followed, except that the ligand in step D was replaced with 2,2-diphenyl [(3-trimethylsilylcyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane.

A. Preparation of 1,1,1,1-diphenyl [(3-trimethylsilyl-cyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] methane

Methodology:

The procedure for preparing this ligand is the same as in Example 1, step B, except that 2,2 - [(cyclopentadienyl) (fluorenyl)] propane is replaced by 2,2-diphenyl [(cyclopentadienyl) (fluorenyl)] propane .

B. Preparation of 2,2-diphenyl [(cyclopentadienyl) - (3,6-di-tert-butylfluorenyl)] propane

Methodology:

The procedure for obtaining this ligand is the same as in Example 1, step D, except that 1,6,6-trimethyl-3-tert-butyl fulvene is replaced with 6,6-diphenylfulven.

Example 9

Polymerization techniques.

All polymerizations were carried out in a laboratory reactor with a volume of 4 liters; pure polypropylene served as a raw material. The polymerization was initiated by the introduction of metallocene (0.5 to 5 mg) previously contacted with 1 ml of MAO (methylaluminoxane) (30% solution in toluene, purchased from WITCO) for three minutes before it was introduced into the reactor.

Table 1 presents data on the microtacticity of the polymer obtained using the catalyst according to example 1, under the polymerization conditions described above. The results were obtained using ¹³ C NMR spectroscopy. It is obvious that polypropylene contains more than 95% pentad in pure isotactic form (mmmm). The molecular weight (Mw) of polypropylene is 530000, and the melting point is 153 ° C. The melting point was determined by DSC, as shown in Fig.13. The sample was kept at 25 ° C for 1 minute, heated from 25 ° C to 220 ° C at a rate of 20 ° C / min and kept at 220 ° C for 5 minutes. Then the sample was cooled from 220 ° C to 25 ° C at a speed of 20 ° C / min, kept at 25 ° C for 3 minutes and heated from 25 ° C to 220 ° C at a speed of 20 ° C / min.

Table 1
The distribution of stereoregular sequences in pentads,% mmmm 95.7 mmmr 1.70 rmmr 0.00 mmrr 1.70 mrmm + rmrr 0.00 mrmr 0.00 rrrr 0.00 mrrr 0.00 mrrm 0.80 table 2 No. Tpolim. ° C Hydrogen M12 Activity T melt T Recrist. Mn Mw Mz D mmmm,% 1 60 ° C 0 NI 11229 160,5 110.9 140620 450834 971672 3.2 96.23 2 60 ° C 0 NI 4889 156.8 115.6 152183 576644 1238131 3.8 95.15 3 60 ° C 0 NI 0.5 15772 161.4 114.0 151062 515399 1092618 3.4 96.07 4 80 ° C 0 NI 21859 155.7 102.7 90958 215031 417006 2,4 94.18 5 60 ° C 0 NI 24115 159.5 112.9 177211 637977 1344283 3.6 96.16 6 80 ° C 0 NI 1.9 41546 154.9 106.9 119201 286072 568665 2,4 95.17 7 40 ° C 0 NI 1117 157.2 112.2 186032 1363315 3506808 7.3 97.30 8 60 ° C 1 NI 14.7 36530 161.7 116.1 64952 199020 727048 3,1 97.10 nine 60 ° C 2 NI 158.0 25659 160,5 116.5 35877 94120 174790 2.6 97.50 After xylene extraction No. Tpolim. ° C Hydrogen Solubility in xylene,% Mn Mw Mz D mmmm,% 1 60 ° C 0 NI 0.58 119675 425468 1004487 3.6 95.3 3 60 ° C 0 NI 0.60 143213 464465 1032093 3.2 94.6 8 60 ° C 1 NI 0.14 69301 204803 447736 3.0 97.0

Table 2 shows other examples of the production of isotactic polypropylene using the catalyst obtained according to example 1, under the above polymerization conditions. Obviously, the resulting isotactic polypropylene contains in some cases over 97% pentad in pure isotactic form (mmmm). At 40 ° C and 60 ° C, polymers were obtained with high mass average molecular weights, especially without the addition of hydrogen. It was found that the polymerization temperature of about 60 ° C is especially favorable because at this temperature polymers with relatively high molecular weights are obtained in combination with good microtacticity and high catalyst activity.

Claims (31)

1. The metallocene component of the catalytic system for producing a polyolefin comprising an isotactic polyolefin or a syndiotactic / isotactic block polyolefin having a monomer length of up to C ₁₀ , said component having the general formula: R "(CpR ₁ R ₂ R ₃ ) (Cp'R ₁ 'R ₂ ') MQ ₂ , where Cp is a cyclopentadienyl ring substituted with at least one substituent; Cp 'is a substituted fluorenyl ring; R "is the structural bridge imparting stereochemical rigidity to the component; R ₁ is hydrogen or a substituent in the cyclopentadienyl ring located remotely with respect to the bridge, said remote substituent including a bulky group of the formula XR $\genfrac{}{}{0ex}{}{\text{*}}{\text{3}}$ where X is selected from an IVA group, and R ^* is the same or different and selected from hydrogen or a hydrocarbon radical containing from 1 to 20 carbon atoms; R ₂ is hydrogen or a substituent in the cyclopentadienyl ring closest to the bridge and not vicinal to the remote substituent, having the formula YR $\genfrac{}{}{0ex}{}{\text{\#}}{\text{3}}$ where Y is selected from an IVA group, and R ^# are the same or different and are selected from hydrogen or a hydrocarbon radical containing from 1 to 7 carbon atoms; R ₃ is hydrogen or a substituent in the cyclopentadienyl ring closest to the bridge and represents a hydrogen atom or has the formula ZR $\genfrac{}{}{0ex}{}{\text{\$}}{\text{3}}$ where Z is selected from an IVA group, and R ^$ are the same or different and selected from hydrogen or a hydrocarbon radical containing from 1 to 7 carbon atoms, provided that at least one of R ₁ , R ₂ or R _{3 is} not hydrogen; R ₁ ′ and R ₂ ′ are independent substituent groups on the fluorenyl ring, one of which is a group of the formula AR ″ ″ ₃ , where A is selected from an IVA group and each of R ″ ″ independently represents hydrogen or a hydrocarbon radical, containing from 1 to 20 carbon atoms, and the other one is hydrogen or a second group of the formula AR ″ ₃ ; M is a transition metal of the IVB group or vanadium; and each Q is a hydrocarbon radical containing from 1 to 20 carbon atoms, or halogen. 2. The metallocene component of the catalyst system according to claim 1, in which R ₁ 'and R ₂ ' are in positions 3 and 6 of the fluorenyl ring. 3. The metallocene component of the catalyst system according to claim 1 or 2, in which a represents carbon or silicon. 4. The metallocene component of the catalyst system according to claim 3, in which AR ″ ″ ₃ is a hydrocarbon radical containing from 1 to 20 carbon atoms. 5. The metallocene component of the catalyst system according to claim 4, in which AR ″ ″ ₃ is C (CH ₃ ) ₃ . 6. The metallocene component of the catalyst system according to claim 2, in which AR ″ ″ ₃ is Si (CH ₃ ) ₃ . 7. The metallocene component of the catalyst system according to any one of claims 1 to 6, in which R ₁ 'and R ₂ ' are the same. 8. The metallocene component of the catalyst system according to any one of claims 1 to 7, in which R ’’ is an alkylidene having from 1 to 20 carbon atoms, dialkyl-germanium or silicon or siloxane, alkylphosphine or an amine. 9. The metallocene component of the catalyst system of claim 8, in which R "represents isopropylidene, dimethylsilanediyl or diphenylmethylidene. 10. The metallocene component of the catalyst system according to any one of claims 1 to 9, in which M represents zirconium or titanium. 11. The metallocene component of the catalyst system according to any one of claims 1 to 10, in which Q is halogen. 12. The metallocene component of the catalyst system according to any one of claims 1 to ₁₁ , in which R ₁ represents C (CH ₃ ) ₃ , C (CH ₃ ) ₂ Ph, CPh ₃ or Si (CH ₃ ) ₃ . 13. The metallocene component of the catalyst system according to item 12, in which R ₁ represents C (CH ₃ ) ₃ . 14. The metallocene component of the catalyst system according to any one of claims 1 to 13, in which Y is carbon. 15. The metallocene component of the catalyst system according to any one of claims 1 to 14, in which Z represents carbon. 16. The metallocene component of the catalyst system according to any one of claims 1 to 15, in which R ₂ represents CH ₃ . 17. The metallocene component of the catalyst system according to any one of claims 1 to 16, in which R ₃ represents CH ₃ . 18. The metallocene component of the catalyst system according to any one of claims 1-17, wherein the metallocene catalyst component comprises isopropylidene-3-tert-butyl-5-methylcyclopentadienyl-3,6-di-tert-butylfluorenyl-ZrCl ₂ . 19. The metallocene component of the catalyst system according to any one of claims 1 to 18, in which the metallocene catalyst component includes (i) a catalyst component according to any one of claims 1 to 18; and (ii) its regioisomer, in which R ₂ is closest to the bridge and located vicinally to the remote substituent. 20. The metallocene component of the catalyst system according to any one of claims 1 to 17, in which the metallocene catalyst component includes isopropylidene (3-tert-butyl-5-methylcyclopentadienyl-3,6-di-tert-butylfluorenyl) ZrCl ₂ and isopropylidene- ( 3-tert-butyl-2-methylcyclopentadienyl-3,6-di-tert-butylfluorenyl) ZrCl ₂ . 21. The metallocene component of the catalyst system according to any one of claims 1 to 20, in which the catalyst component is part of a catalyst system, which further includes an aluminum or boron-containing cocatalyst capable of activating the catalyst component. 22. The metallocene component of the catalyst system according to claim 17, wherein the catalyst system further comprises an inert carrier. 23. The metallocene component of the catalyst system according to any one of claims _{1 to 13} , wherein R ₁ is a substituent on the cyclopentadienyl ring and the polyolefin is a syndiotactic / isotactic block polyolefin. 24. The metallocene component of the catalyst system according to any one of claims _{1 to} 17, in which R ₁ and R ₂ are both substituents on the cyclopentadienyl ring, and the polyolefin is an isotactic polyolefin. 25. The metallocene component of the catalyst system according to claim 19 or 20, in which the polyolefin comprises an isotactic polyolefin having a multimodal molecular weight distribution. 26. A method for producing polyolefins having a monomer length of up to C ₁₀ , which comprises contacting a catalyst system containing a metallocene component according to any one of claims. 1-22, with at least one olefin in the reaction zone under polymerization conditions to form an isotactic polyolefin or syndiotactic / isotactic block polyolefin. 27. The method according to p, in which the olefin is propylene. 28. The method according to p, in which two or more olefins are present in the reaction zone to produce a polyolefin copolymer. 29. An isotactic polyolefin having a monomer length of up to C ₁₀ obtained by the method according to any one of claims. 26-28, having a pentad distribution comprising at least 87% mmmm, as measured by ¹³ C NMR, in which the number of 2-1 and 1-3 insertions of the monomer in the polyolefin is not detected, and the weight average molecular weight is at least 450,000. 30. The polyolefin of claim 29, wherein the pentad distribution comprises at least 95% mmmm as measured by ¹³ C NMR. 31. The polyolefin according to clause 29 or 30, which includes polypropylene.

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