WO2000004056A1

WO2000004056A1 - Heterogeneous catalyst systems with kaolin as the support for olefin polymerisation

Info

Publication number: WO2000004056A1
Application number: PCT/EP1999/004976
Authority: WO
Inventors: Karin Weiss; Sandra Botzenhardt; Monika Hofmann; Eike Poetsch; Herwig Buchholz
Original assignee: Universität Bayreuth; Merck Patent Gmbh
Priority date: 1998-07-15
Filing date: 1999-07-14
Publication date: 2000-01-27
Also published as: EP1098913A1; KR20010071854A; CA2337255A1; DE19831804A1; BR9912071A; JP2002520451A

Abstract

The invention relates to heterogeneous catalyst systems for olefin polymerisation. Said catalyst systems consist of one or more organometallic compounds containing a metal of the 3?rd or 4th¿ main group of the periodic system, one or more transition metals containing a metal of the 3?rd to 8th¿ subgroup of the periodic system, and kaolin as the support.

Description

Heterogeneous catalyst systems with kaolin as a carrier for the

Olefin polymerization

DESCRIPTION

The present invention relates to heterogeneous catalyst systems for olefin polymerization, their preparation and use.

Polyolefin technology has become a major branch of the chemical industry in the past 50 years. Development began with Ziegler-Natta catalysis, which made it possible for the first time to display polyethylene (PE), polypropylene (PP) and copolymers on a large scale. Ziegler-Natta catalyst systems consist of an organometallic compound of a metal from main group 1 to 4 of the periodic table and a compound of a transition metal from subgroups 3 to 8. The first Ziegler-Natta catalysts used contained TiC14 and an aluminum trialkyl. The Ziegler-Natta process was further developed through the use of heterogeneous catalyst systems (Himont catalysts). Heterogeneous catalyst systems are characterized in that the catalysts are applied to supports, for example A1 ₂ 0 ₃ or MgCl ₂ .

Heterogeneous catalyst systems which consist of TiCl ₄ , VC1 ₄ or V0C1 ₃ as catalysts, aluminum alkyls as cocatalysts and silicon dioxide, aluminum oxides or aluminum silicates as supports are described, for example, in EP 260 130 A and US Pat. No. 5,002,916.

About 10 years ago, with metallocene compounds of Ti, Zr and Hf in combination with methylaluminoxane (MAO) as a cocatalyst, new types of highly reactive catalysts were used for the first time for the preparation of PE and PP (R. Mühlhaupt, Nachr. Che. Tech. Lab. 41 (1993) 1341). In homogeneous solution, however, these catalyst systems easily result in reactor fouling (ie the polymer formed sticks to the reactor walls). Therefore, the heterogenization of these homogeneous metallocene catalysts has been advanced in recent years.

Numerous patents and scientific publications for the representation of such heterogeneous catalyst systems exist. They preferably use silica gel, silicates, aluminum oxides or aluminum silicates as carrier materials (WO 93/04628; US 4, 912 075; US 4, 925 821, WO 96, 043 18 and L. Minkova, Europ. Pol. J. 7 (1988 ) 661).

In addition to a catalyst and a cocatalyst, heterogeneous catalyst systems can also contain fillers which are supports for the catalyst and cocatalyst. For example, WO 96/34900 describes catalyst systems which comprise a wide variety of fillers in addition to organometallic compounds as cocatalysts and transition metal compounds as catalysts. In F. Hindryckx, J. Appl. Polym. Be. 64 (1997) 423 describes a catalyst system which contains inorganic fillers (kaolin, barite) in addition to (BuO) 4Ti, BuMgOct, EtAlC12 and Et3Al. From D. Damyanov, Europ. Pole. J. 7 (1988) 657 a catalyst system is also known which consists of titanium tetrachloride, diethyl aluminum chloride, diphenylmagnesium and kaolin, chalk or dolomite.

For the previously known heterogeneous catalyst systems composed of Ti, Zr and Hf metallocenes or Ti and V halides as catalysts and aluminum alkyls as cocatalysts, which may contain fillers, it can be seen that they are well suited for industrial use in olefin polymerization are. They enable gas phase reactions, fluidized bed processes and prevent reactor fouling. The activities of these heterogeneous catalyst systems, including the catalyst systems that the above Fillers contain, but are inadequate compared to the activities of homogeneous catalyst systems.

In addition, the known high molecular weight polymers are not generally obtained with the known catalyst systems.

The object of the present invention is to provide heterogeneous catalyst systems which have high activities, cause little or no reactor fouling and at the same time allow the production of polymers of high molecular weights (up to the range of about 10 ⁶ ).

This problem is solved by the provision of heterogeneous catalyst systems that consist of

(a) one or more organometallic compounds which contain a metal from the 3rd or 4th main group of the periodic table,

(b) one or more transition metal compounds which contain a metal from subgroup 3 to 8 of the periodic table, and

(c) Kaolin as a carrier for the organometallic compounds (a) and transition metal compounds (b) exist.

Organometallic compounds (a) which are free of halides are preferred. Organometallic compounds (a) are particularly preferred here, the organic radicals selected from alkyl, alkenyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy, alkaryloxy and aralkoxy radicals in which the hydrocarbon radicals are straight-chain, branched or cyclic and can optionally be substituted and preferably have 1-20 C atoms, and optionally additionally contain hydrogen as a substituent.

Preferred metals contained in the organometallic compounds (a) are boron, aluminum, silicon and tin. Arylboron and alkylarylboron compounds in which the aryl and alkyl radicals can be substituted, trialkylaluminum compounds in which the optionally substituted alkyl groups are identical or different and / or tetraalkyltin compounds are advantageously used as organometallic compounds (a).

Of these compounds, trialkyl aluminum compounds, and especially triethyl aluminum, triethyl aluminum, tripropyl aluminum and triisobutyl aluminum, are particularly preferred.

Classic Ziegler-Natta catalysts as well as bridged or unbridged metallocene catalysts can be used as transition metal compounds (b) which contain a metal from subgroup 3 to 8 of the periodic table.

Transition metal compounds (b) of titanium, zirconium, hafnium or vanadium are preferred.

Compounds which are halides, oxide halides, alkyloxy compounds or aryloxy compounds of transition metals of subgroup 3 to 8 are preferably used as classic Ziegler-Natta catalysts. Titanium tetrahalides, tetra (alkoxy) titanium and alkoxytitanium halides, vanadium halides, vanadium oxide halides and alkoxyvanadium compounds in which the alkyl groups which may be present have 1-20 C atoms are particularly preferred.

Metallocene catalysts can be complexes that have one or more identical or different metal π-bonded

Contain ligands. Metal π-bonded ligands are, for example, cyclopentadienyl, indenyl, tetrahydroindenyl, benzoindenyl, fluorenyl, octahydrofluorenyl and substituted cyclopentadienyl, indenyl, tetrahydroindenyl, Benzoindenyl, fluorenyl, octahydrofluorenyl ligands. As substituents of the metal π-bonded ligands, straight-chain, branched and / or cyclic alkyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy, alkylboron, alkylsilyl, alkylgermanyl, alkylstannyl, alkylplumbyl, Alkylamino and / or alkylphosphinic groups may be present, which are optionally halogenated.

In addition to the metal π-bonded ligands, the transition metal compounds (b) can contain metal-σ-bonded ligands, for example halogens, straight-chain, branched and / or cyclic alkyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy groups and, if appropriate amino, phosphine, boron, silyl and / or carbene groups substituted with the above groups.

The π-bonded ligands can be bridged to one another or with a σ-bonded ligand. Bridging groups are for example

, Silyl, Germanyl, amino or phosphine groups, which can be substituted, for example, with alkyl, aryl, aralkyl, alkaryl and / or silyl groups.

Examples of useful transition metal compounds (b) are titanium tetrachloride, tetra (methoxy) titanium, vanadium trichloride, vanadium tetrachloride, vanadium oxide trichloride, cyclopentadienyl dienyltitantrichlorid, pentamethylcyclopentadienyl titanium trichloride, cyclopentadienyl zirconium trichloride, pentamethylcyclopentadienyl zirconium trichloride, dicyclopentadienyltitanium dichloride, dicyclopentadienyl titanium diphenyl, bis (methylcyclopentadienyl) titanium dichloride, bis (1, 2-dimethylcyclopentadienyl) titanium dichloride, bis (1,2-diethylcyclopentadienyl) titanium dichloride, dicyclopentadienyl titanium carbenes, dicyclopentadienylzirconium dichloride, dicyclopentadienylzirconium diphenyl, Bis (methylcyclopentadienyl) zirconium dichloride,

Bis (pentamethylcyclopentadienyl) zirconium dimethyl,

Bis (ethylcyclopentadienyl) zirconiumdimethyl, bis (1, 3-diethyl-cyclopentadienyl) zirconium dichloride, bis (ß-phenylpropyl-cyclopentadienyl) zirconiumdimethyl, bis (indenyl) titanium diphenyl bis (indenyl) titanium dichloride, ethenyldichidyldiridylidyldichlorid, ethenyldichloridylidyldichlorid, ethenyldichloridylidyldichlorid, dimethylsilyl-bis (tetrahydroindenyl) zirconium dichloride, Dimethylsiliyl-bis- (2-methyl-4-tert-butylcyclopentadienyl) - zirconium dichloride, methylenedicyclopentadienyl, Dimethylsilyldicyclopentadienylzirconiumdichlorid, diphenylmethylene (fluorenyl) (cyclopentadienyl) zirconium dichloride, isopropylene (fluorenyl) (cyclopentadienyl) - zirconium dichloride, Methylphosphinedicyclopentadienyl zirconium dichloride, methylenedicyclopentadienyl zirconium dimethyl, dicyclopentadienyl zirconium (diphenylmethyl phosphine) carbene, dicyclopentadienyl hafnium dichloride, dicyclopentadienylvanadium dichloride.

Particularly preferred compounds are dicyclopentadienyl zirconium dichloride, dicyclopentadienyl titanium dichloride, vanadium tetrachloride and titanium tetrachloride.

Mixtures of the transition metal compounds (b) can be used, both mixtures of classic Ziegler-Natta catalysts with one another and mixtures of metallocene catalysts with one another and also mixtures of classic Ziegler-Natta catalysts with metallocene catalysts.

Kaolin with a surface area of 10 to 1000 m ² / g is preferably used.

Components (a) and (b) in the heterogeneous catalyst system are preferably in a molar ratio of 3000-5: 1 and particularly preferably in a molar ratio of 500-25: 1 before.

Furthermore, there are preferably 0.25-6 mmol of organometallic compound (a) per 1 g of kaolin (c), particularly preferably 0.5-4 mmol of organometallic compound (a) per 1 g of kaolin (c) and 0.0005-0.06 mmol of transition metal compound (b) per 1 g of kaolin (c), particularly preferably 0.002-0.06 mmol of transition metal compound (b) per 1 g of kaolin (c).

The heterogeneous catalyst systems according to the invention can be produced by one of the following processes:

Procedure A:

In a first process step, the kaolin is placed in suspension in an inert solvent. The organometallic compound (a) is then added, preferably as a solution or suspension. After a reaction time dependent on the respective starting compounds, the transition metal compound (b), advantageously dissolved or suspended in a solvent, is added in a further step. After a reaction time that is also variable depending on the compounds used, the product can be purified.

Procedure B:

The kaolin is placed in suspension in an inert solvent. A mixture of the organometallic compound (a) and the transition metal compound (b), preferably as a solution or suspension, is then added. After a variable reaction time depending on the compounds used, the product can be cleaned.

All process steps are preferably carried out in a protective gas atmosphere. As a protective gas, the Usually used gases, for example argon or nitrogen, are used.

Solvents which serve to suspend the kaolin are inert solvents, for example pentane, isopentane, hexane, heptane, octane, nonane, cyclopentane, cyclohexane, benzene, toluene, ethylbenzene and diethylbenzene.

Solvents in which the organometallic compounds (a) can be dissolved or suspended are preferably pentane, isopentane, hexane, heptane, octane, nonane, cyclopentane, cyclohexane, benzene, toluene, ethylbenzene and diethylbenzene.

Solvents in which the transition compounds (b) can be dissolved or suspended are preferably pentane, isopentane, hexane, heptane, octane, nonane, cyclopentane, cyclohexane, benzene, toluene, ethylbenzene and diethylbenzene.

After the first reaction step, a cleaning step can preferably be carried out. Cleaning is particularly preferably carried out by washing with one of the above. inert solvents.

When the kaolin reacts with the organometallic compound (a) in the first reaction step of process A, a surface-fixed organometalloxane is formed.

The reaction times of the kaolin with the organometallic compound (a) and the surface-fixed organometalloxane with the transition metal compound (b) in process A are very variable depending on the starting compounds. When carrying out process B, the reaction time of the kaolin with the mixture of organometallic compound (a) and transition metal compound (b) is also very variable. The reactions can be ended by chemical (eg reaction with water) or spectroscopic Examination of the reaction solution for the content of unreacted starting compound can be found.

The reaction temperature for all reaction steps of both processes is between -20 ° C and + 50 ° C, preferably at room temperature.

The heterogeneous catalyst system obtained by the above reaction can be purified using the conventional methods, washing with one of the abovementioned is preferred. Solvent.

If the catalyst system is then to be dried, the use of a low-boiling solvent, for example pentane, is recommended for washing.

The solvent can then be removed in vacuo. The dried catalyst can be stored under suitable conditions (oxygen and water-free atmosphere).

The heterogeneous catalyst systems described above and obtained with the above processes can be used for the polymerization of olefins. Usable olefins are, for example, ethylene, propylene, but-l-ene, pent-1-ene, hex-l-ene, oct-l-ene, hexadec-1-ene, octadec-1-ene, 3-methylbut-l -en, 4-methylpent-1-ene, 4-methylhex-l-ene, diolefins, for example 1, 3-butadiene, 1, 4-hexadiene, 1, 5-hexadiene, 1, 6-octadiene, 1,4 Dodecadiene, aromatic olefins, for example styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, indene, vinylanthracene, vinylpyrene, 4-vinylbiphenyl, Dimethano-octahydro-naphthalene, acenaphthalene, vinyl fluorene, vinyl chrysene, cyclic olefins and diolefins, for example cyclopentene, 3-vinylcyclohexene, dicyclopentadiene, norbornene, 5-vinyl-2-norbomene, tert-ethylidene-2-norbornene, 7-octenyl 9-borabicyclo- (3, 3, dnonane, 4-vinylbenzocyclobutane, tetracyclododecene. Acrylic acid, methacrylic acid, methyl methacrylate, ethyl acrylate, acrylonitrile, 2-ethylhexyl acrylate, methacrylonitrile, maleimide, N-phenyl-maleimide, vinylsilane, phenylsilane, trimethylallylsilane, vinyl chloride, vinylidene chloride, isobutylene can be used. The catalyst systems according to the invention are preferably used for the polymerization of ethylene, propylene and 1-olefins, for the copolymerization of ethylene, propylene, 1-olefins, cycloolefins and / or dienes.

The production of heterogeneous catalyst systems according to the invention is described in detail using the following exemplary embodiments. The implementation of the olefin polymerization using the catalyst systems described is also listed.

example 1

a) Preparation of the heterogeneous catalyst system: 5 g of kaolin (Al ₂ Si ₂ 0 ₅ (OH) ₄ ) are placed in a Schlenk tube under an inert gas atmosphere (argon) and suspended in 15 ml of absolute toluene. 12 mmol (6 ml) of trimethyl aluminum (2.0 M solution in n-heptane) are then slowly added dropwise. This reaction mixture is allowed to stir slowly at room temperature for 72 hours before 7.02 mg = 0.024 mmol (0.48 ml) of dicyclopentadienylzirconium dichloride (0.05 M solution in toluene) is added and this mixture is left to stir for a further 4 hours. The supernatant solution is then decanted off and the residue is washed twice with 10 ml of toluene each time. b) Polymerization: The polymerization is carried out in an 11 reactor which has been previously evacuated and gassed. The heterogeneous catalyst system prepared in la) and 200 ml of heptane are added to the reactor, which is heated to 30 ° C. Then 10 bar of ethylene are injected. After 45 minutes, the reaction is stopped by releasing the pressure. No fouling occurred in this reaction.

Yield: 94.85 g PE; M _η = 0.38 • 10 ⁶ g / mol; T _M = 137.7 ° C Activity A = 5269 kg PE / mol Zr ^• h

Example 2

a) Preparation of the heterogeneous catalyst system: 5 g of kaolin (Al ₂ Si ₂ 0 ₅ (OH) ₄ ) are placed in a Schlenk tube under an inert gas atmosphere (argon) and suspended in 15 ml of absolute toluene. 12 mmol (13.6 ml) of triisobutyl aluminum (25% solution in n-hexane) are then slowly added dropwise. This reaction mixture is allowed to stir slowly at room temperature for 72 hours before 7.02 mg = 0.024 mmol (0.48 ml) of dicyclopentadienylzirconium dichloride (0.05 M solution in toluene) is added and this mixture is left to stir for a further 4 hours. The supernatant solution is then decanted off and the residue is washed twice with 10 ml of toluene each time. b) Polymerization: The polymerization is carried out in a II reactor which was previously evacuated and gassed. The heterogeneous catalyst system prepared in 2a) and 200 ml of heptane are added to the reactor, which is heated to 30 ° C. Then 10 bar of ethylene are injected. After 60 minutes, the reaction is stopped by releasing the pressure. No fouling occurred in this reaction.

Yield: 19.25 g PE; M _η = 0.42 ^• 10 ⁶ g / mol; T _M = 137.3 ° C activity A = 802 kg PE / mol Zr • h

Example 3

a) Preparation of the heterogeneous catalyst system: 5 g of kaolin (Al ₂ Si ₂ 0 ₅ ) (OH) ₄ ) are placed in a Schlenk tube under an inert gas atmosphere (argon) and suspended in 15 ml of absolute toluene. 12 mmol (6 ml) of trimethyl aluminum (2.0 M solution in n-heptane) are then slowly added dropwise. This reaction mixture is allowed to stir slowly at room temperature for 72 hours before 5.98 mg = 0.024 mmol (0.48 ml) of dicyclopentadienyltitanium dichloride (0.05 M solution in toluene) and this mixture is stirred for a further 4 hours. Then the supernatant solution is decanted off, and the residue is washed twice with 10 ml of toluene, b) Polymerization: The polymerization is carried out in a II reactor which was previously evacuated and gassed. The heterogeneous catalyst system prepared under 3a) and 200 ml of heptane are added to the reactor, which is heated to 30 ° C. Then 10 bar of ethylene are injected. After 60 minutes, the reaction is stopped by releasing the pressure. No fouling occurred in this reaction.

Yield: 35.12 g PE; M _η = 1.9 ^• 10 ^β g / ol; T _M = 137.0 ° C activity A = 1463 kg PE / mol Ti ^• h

Example 4

a) Preparation of the heterogeneous catalyst system: 5 g of kaolin (Al ₂ Si ₂ 0 ₅ (OH) ₄ ) are placed in a Schlenk tube under an inert gas atmosphere (argon) and suspended in 15 ml of absolute toluene. 6 mmol (3 ml) of trimethylaluminum (2.0 M solution in n-heptane) are then slowly added dropwise. This reaction mixture is allowed to stir slowly at room temperature for 72 hours before 45.5 mg = 0.24 mmol (0.026 ml) of titanium tetrachloride are added and this mixture is left to stir for a further 4 hours. The supernatant solution is then decanted off and the residue is washed twice with 10 ml of toluene each time. b) Polymerization: The polymerization is carried out in a II reactor which was previously evacuated and gassed. The heterogeneous catalyst system prepared under 4a) and 200 ml of heptane are added to the reactor, which is heated to 30 ° C. Then 10 bar of ethylene are injected. After 45 minutes, the reaction is stopped by releasing the pressure. Slight fouling occurred in this reaction. Yield: 106.0 g PE; M _η = 1.15 ^• 10 ^ g / mol; T _M = 137, 1 ° C activity A = 589 kg PE / mol Ti ^• h

Example 5

a) Preparation of the heterogeneous catalyst system: 5 g of kaolin (Al ₂ Si ₂ 0 ₅ (OH) ₄ ) are placed in a Schlenk tube under an inert gas atmosphere (argon) and suspended in 15 ml of absolute toluene. 6 mmol (3 ml) of trimethylaluminum (2.0 M solution in n-heptane) are then slowly added dropwise. This reaction mixture is allowed to stir slowly at room temperature for 72 hours before 46.26 mg = 0.24 mmol (0.39 ml) of vanadium tetrachloride (solution in n-hexane: 120 mg / ml) is added and this mixture is stirred for a further 4 hours leaves. The supernatant solution is then decanted off and the residue is washed twice with 10 ml of toluene each time. b) Polymerization: The polymerization is carried out in a II reactor which was previously evacuated and gassed. The heterogeneous catalyst system prepared under 5a) and 200 ml of heptane are added to the reactor, which is heated to 30 ° C. Then 10 bar of ethylene are injected. After 3 minutes, the reaction is stopped by releasing the pressure. Slight fouling occurred in this reaction.

Yield: 52.46 g PE; _η = 2.9 ^• 10 ⁶ g / mol; T _M = 137.2 ° C activity A = 4372 kg PE / mol V ^• h

In summary, it can be stated that high activities can be achieved with the kaolin-supported catalyst systems according to the invention, with little or no reactor fouling being observed and, at the same time, polymers with a very high molecular weight being obtained.

Claims

PATENT CLAIMS

1. Heterogeneous catalyst systems for olefin polymerization consisting of

(c) Kaolin as a carrier for the organometallic compounds (a) and the transition metal compounds (b).

2. Heterogeneous catalyst systems according to claim l, characterized in that the organometallic compounds (a) organic radicals selected from alkyl, alkenyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy, alkaryloxy and aralkoxy radicals and optionally additionally hydrogen included as substituents.

3. Heterogeneous catalyst systems according to claim 2, characterized in that the organometallic compounds (a) are one or more compounds selected from arylboron and alkylarylboron compounds, trialkylaluminum compounds and / or tin alkyl compounds.

4. Heterogeneous catalyst systems according to claim 3, characterized in that the organometallic compounds (a) trialkyl aluminum compounds selected from trimethyl aluminum, triethyl aluminum, tripropyl aluminum and / or triisobutyl aluminum.

5. Heterogeneous catalyst systems according to one of claims 1 to 4, characterized in that the transition metal compounds (b) are bridged or unbridged metallocenes.

6. Heterogeneous catalyst systems according to one of claims 1 to 4, characterized in that the transition metal compounds (b) are halides, oxide halides, alkyloxy compounds and / or aryloxy compounds.

7. Heterogeneous catalyst systems according to one of claims 5 or 6, characterized in that the transition metal compounds (b) are compounds of titanium, zirconium, hafnium or vanadium.

8. Heterogeneous catalyst systems according to claim 7, characterized in that the transition metal compounds (b) are titanium tetrachloride, vanadium tetrachloride, dicyclopentadienylzirconium dichloride and / or dicyclopentadienyl titanium dichloride.

9. Heterogeneous catalyst systems according to one of claims 1 to 8, characterized in that the kaolin a

Has surface area of 10 to 1000 m / g.

10. Heterogeneous catalyst systems according to one of claims 1 to 9, characterized in that components (a) and

(b) present in a molar ratio of 3000-5: 1.

11. Heterogeneous catalyst systems according to one of claims 1 to 10, characterized in that 0.25 - 6 mmol of the organometallic compounds (a) are present per 1 g of kaolin.

12. Heterogeneous catalyst systems according to one of claims 1 to 11, characterized in that 0.0005-0.06 mmol of transition metal compounds (b) are present per 1 g of kaolin.

13. A method for producing heterogeneous catalyst systems according to one of claims 1 to 12 comprising the steps: (i) Suspend kaolin in an inert

Solvent (ii) reacting the kaolin with

(1) one or more organometallic compounds (a) and subsequently with one or more transition metal compounds (b) or

(2) a mixture of one or more organometallic compounds (a) and one or more transition metal compounds (b).

14. Use of a catalyst system according to one of claims 1 to 13 for olefin polymerization.