CS253592B2 - Multicomponent catalyst composition and process for its manufacture - Google Patents

Abstract

A multi-component highly active catalyst composition of the Ziegler or Ziegler-Natta type consists of a) 50 to 95% by weight of solid inert particles of an organic carrier material based on a polyolefin plastic, which has an average particle size of 0.05 to 0.35 mm, a melting point of 70 to 170 °C and a specific gravity of 0.9 to 1.5 g/cm^ and b) 5 to 50% by weight of solid particles of a catalyst precursor formed by a compound based on a transition metal from group IVa, Va or Via of the periodic table of elements, for low-pressure polymerization of olefins, wherein the catalyst precursor particles are adhered to the particles of the organic carrier material. The method of producing this catalyst composition is based on mixing components a) and b) at high speed at an elevated temperature achieved by friction of the components, until a product with precisely defined properties is obtained. The composition is intended for use in low-pressure polymerization in the gas phase in a fluidized bed.

Description

The present invention relates to multi-component, high-activity olefin polymerization catalyst compositions adapted for use in a low pressure gas phase polymerization process. In particular, the present invention relates to catalysts adapted for use in a low-pressure, gas-phase fluidized bed polymerization process. Also disclosed is a process for making the multi-component highly active catalyst composition.

The transition metal olefin polymerization catalysts that were first developed were used under low pressure conditions in solvents or liquid diluents under solvent or liquid diluent conditions under solution or suspension polymerization conditions. Later advances in the olefin polymerization technology have allowed some of the catalysts to be used in the low pressure gas phase process, where solvent or liquid diluent, if any, is rarely used. For use in such low pressure gas phase processes, various types of catalysts have been treated in various ways to act catalytically in practice. Although various catalyst modification techniques have been used, such as different types of supports that have facilitated the use of these catalysts in different types of gas phase processes, it has been found that there is a need to further modify known components of these catalyst systems to allow such catalyst systems to be used. in a simpler manner in fluidized bed processes to achieve commonly desired results for the polymers produced.

U.S. Pat. Nos. 4,048,415, 4,135,045, and 4,296,222 disclose that an olefin polymerization catalyst useful under low pressure conditions can be milled or micropolymerizable to provide suitable transition metal catalyst forms without the use of catalyst supports. U.S. Pat. No. 3,718,635 discloses the use of a low pressure olefin polymerization catalyst on a milled bead carrier that is supported on certain metal oxide supports. The catalysts of these patents are all intended for use in the presence of an inert solvent or a liquid diluent.

Canadian Patent No. 1,144,300 describes the production of ground bead catalysts for the polymerization of olefins in the presence of magnesium halides as carriers. Inorganic or organic diluents such as silica-silica and polyethylene may be added during or after the bead milling step. The catalyst system is intended for use in a low pressure gas phase fluidized bed process.

However, catalyst systems produced by such a bead or micropulverization process with inorganic or organic carriers or diluent materials have disadvantages in that they have the disadvantage of using such catalyst systems in low pressure gas phase polymerization processes, and particularly with respect to catalyst systems, to be used in the fluidized bed process, the morphology of these catalyst systems, i.e. their particle size and shape, makes it difficult to feed them into the reactor in dry bulk form and also to fluidize them in the reactor. These dosing and fluidization problems can lead to the formation of polymer platelets and lumps in the safaotic reactor and / or recirculated gas conduit, which can interrupt the operation conditions in the reactor due to fouling of the feed recirculation and discharge lines. The polymers produced with such catalysts are also suitable for low bulk density due to the irregular particle size and their relatively small size. These characteristics of such polymers can also contribute to the contamination of the reactor tubing by platelets and / or polymer lumps.

U.S. Patent No. 3,515,684 discloses a process for producing fluidizable cracking catalysts by agglomeration, at high speed in a paddle mixer, from very finely divided particles of a zeolite-water-oil mixture, as a high speed liquid in a paddle mixer. The resulting agglomerated product forms a dispersion of zeolite particles of about 15 to 150 microns in oil. However, these particles are obtained from oil and further processed before use as a catalytic material in a cracking process.

US Patent No. 28,361 for use discloses the use of a finishing apparatus equipped with high speed blades for the preparation of masterbatches of pigmented polymers including polyethylene and polypropylene.

However, none of these references disclose the use of finishing equipment equipped with high velocity blades for producing olefin polymerization catalysts which are especially adapted for use in a low pressure gas phase polymerization process.

U.S. Patent No. 3,990,993 discloses a method for depositing a small particle size olefin polymerization catalyst on a fabric similar to the submicroscopic fibrous structures of polymeric carriers such as polytetrafluoroethylene and polyethylene using a compressive spray effect in various types of mixers. However, no details are given regarding the use of such catalyst systems in gas-phase polymerization. It would be expected that such supported catalyst systems could not be thoroughly deposited on polymeric fabrics and could easily be separated from them in a turbulent reaction environment such as in a fluidized gas bed, and would also create manufacturing problems due to polymer platelets and lumps.

It is an object of the present invention to provide a multi-component, high-activity transition metal catalyst composition for the polymerization of olefins in a fluidized bed gas phase polymerization process.

The multi-component highly active catalyst composition of the Ziegler or Ziegler-Natta type consists of the present invention

(a) 50 to 95% by weight of solid inert particles of an organic carrier material based on polyolefin plastic having an average particle size of 0.05 to 0.35 mm, a melting point of 70 to 170 ° C and a specific gravity of 0.9 to 1.5 g / cm ³ a

b) 5-50% by weight of particulate catalyst precursor consisting of a Group IVa, Va or VIa transition metal compound for the low pressure olefin polymerization, wherein the catalyst precursor particles are adhered to the organic support material particles.

According to the present invention, it has now been found that solid catalyst precursors consisting of a Group IVa, Va or Via transition metal compound having a high activity for low pressure olefin polymerization can be readily adapted for use in the gas-phase polymerization process for purposes of: a significant improvement in the use of such catalysts by extending the time interval in the reactors mixing the catalyst precursor particles with the organic particulate carrier material in the fin-bladed finishing apparatus under conditions causing the carrier particulate material to bond and the individual precursor the catalyst merges with the combined support materials.

The low pressure olefin polymerization catalyst systems of the present invention include a transition metal catalyst compound and an organometallic activating or cocatalyst compound, and can generally be characterized as Ziegler or Ziegler-Natta type high activity catalyst systems.

By high activity catalyst is meant either

Ziegler catalyst system capable of producing ethylene homopolymers and / or copolymers at a productivity level of the order of at least 200,000, preferably at least 500,000 g of plastic per g of transition metal used in a slurry polymerization process formed with an aliphatic hydrocarbon solvent or liquid monomer solution. in a catalyst, or

Ziegler-Natta stereospecific catalyst system capable of producing stereoregular olefinic polymers in a slurry polymerization process of an aliphatic hydrocarbon solvent or liquid monomer solution at a productivity level of the order of at least 100,000, preferably at least 300,000 g of plastic per g of transition metal used in the catalyst.

The term stereospecific catalyst means a catalyst system adapted to produce a stereoregular polymer, i.e., olefin polymers having an isotacticity of at least 80, preferably at least 90%.

The transition metal compounds are those of Group IVa, Va or VIa of the Periodic Table. Preferred transition metals are titanium, vanadium, zirconium and hafnium. Preferred transition metal catalyst compounds are halides, especially chlorides, oxyhalides and alkoxides.

The compounds have the structure of the general formula

M (OR) _and X _b where

M means titanium, vanadium, zirconium or hafnium,

R is an aliphatic or aromatic hydrocarbon group having from 1 to 14 carbon atoms or a group of formula COR 'in which R' is an aliphatic or aromatic hydrocarbon group having from 1 to 14 carbon atoms,

X is chlorine, bromine, iodine, or mixtures thereof, and is zero or 1, b is 2-4 inclusive, and the sum of a + b is equal to M and is usually 3 or 4 if M is titanium or vanadium and is 4 if M is zirconium or hafnium.

The transition metal compounds may be used singly or in admixture with each other and include:

TiCl ₃ , VCl ₃ , TiCl ₄ , VCl ₄ , Ti (OCH ₃ ) Cl ₃ , Ti (OCgH ₃ ) Cl ₃ , Ti (OCOCH ₃ ) Cl ₃ , Ti (OCOC ₃ H ₃ ) or ₃ ,

ZrCl ₄ and HfCl ₄ .

These transition metal compounds can be used pure when in solid form, or they can be converted to such a solid form by complexing with supported materials that form solid complexes with the transition metal compounds. Such complexing agents include metal compounds of the group IIa of the periodic system, in particular magnesium compounds such as magnesium oxide, magnesium chloride, magnesium bromide, magnesium iodide, MgOCl and mixtures thereof.

Anhydrous magnesium chloride is the most preferred of such compounds.

Transition metal compounds with or without complexing carrier compounds can also be used with an electron donor compound that also forms a complex with transition metal compounds. These electron donor compounds are known per se in the art and also as Lewis bases including esters, ethers, ketones, strong and amines.

These esters, ethers, ketones, strong and amines including such compounds as the alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic and cyclic ethers and aliphatic ketones. Silanes include polysiloxanes, alkoxy-, alkylalkoxy-, and arylalkoxysilanes and halogenated derivatives of such silanes. Preferred silanes are phenyltrimethoxysilane and phenyltriethoxysilanes. Amines include di- and polyamino compounds such as 1,2,4-trimethylpiperazine,

N, N, N-, Ν'-tetramethylethylenediamine, Ν, Ν, Ν, ΝΝ-tetraethylethylenediamine, 2-dimethylaminopyridine, Ν, Ν'-dimethylpiperazine, ortho-phenylenediamine, Ν, Ν'-dibenzylethylenediamine, N, N ' , N-dibenzylethylenediamine and 2,3, N, N'-dimethylnaphthylenediamine. Preferred amines include Ν, Ν, Ν *, Ν'-tetraethylethylenediamine. Preferred esters and ethers are alkyl esters of saturated aliphatic carboxylic acids having 1 to 10 carbon atoms, alkyl esters of aromatic carboxylic acids having 7 to 15 carbon atoms, aliphatic ethers having 2 to 8 carbon atoms, preferably 3 or 4 carbon atoms, cyclic ethers having 3 to 10 carbon atoms. C mon 5 5 5 as výhodou výhodou výhodou výhodou výhodou výhodou výhodou výhodou výhodou výhodou. Most preferred compounds include ethylanisate and tetrahydrofuran.

About 0 to 200, preferably 10 to 80, molar parts of the magnesium compound are used per mole of the complexes obtained by reacting the transition metal compound with an electron donor compound (hereinafter also referred to as ED compound).

About 0 to 3, preferably 1 to 2, molar parts of the electron donor compound are used per mole of transition metal compound.

As used herein, the term catalyst precursor means a transition metal compound alone or combined with a carrier of the compound-forming inorganic compound and / or electron donor compound, but either free of the organic carriers listed below, or a fully activated amount of the activator compound.

The level of productivity of these highly active catalysts is not significantly affected when these catalyst systems are modified as described herein for use in fluidized bed olefin polymerization. However, without the catalyst modification described herein, highly active catalysts cannot be used to achieve high productivity in gas phase processes without significantly adversely affecting the scope of the processes in the reactors in which they have been used.

The activator compounds are preferably organometallic compounds with metals of group Ia, IIa or IIIa of the periodic system, and are more preferably aluminum, zinc, cadmium or magnesium. Most preferred compounds have the structure

where

X 'represents chlorine or an OR group

R and R 'are the same or different and are unsaturated hydrocarbon groups having 1 to 14 carbon atoms, zero to 3 means ^- zero to 1.5 means 1 or zero, and the sum of c + d + e is 3.

The activator compounds can be used singly or in mutual form

About 10 to 400, preferably about 50 to 150, molar parts of the activator compound are used per mole of transition metal compound in the activated catalyst of the present invention.

The electron donor compounds as described above can also be used in the form of complexes with activator compounds to enhance the stereospecificity of Ziegler-Natta-type stereospecific olefin polymerization catalysts. Electron donors and activators in such a case would be used at a molar ratio of activator to electron donor of about 0.5: 1 to 20: 1, preferably about 1: 1 to 5: 1.

The organic carrier materials used in the production of the catalyst systems of this invention are individual polymeric hydrocarbon materials. To facilitate their use in the production of supported catalyst systems, they should preferably have a melting point or glass transition temperature of about 70-170 ° C, preferably about 90-140 ° C, with an average particle size of about 0.05-0.35 mm. and a particle size distribution of not more than 10% by weight of the material with a particle size below 0.02 mm.

To facilitate the use of the supported catalyst system in the gas-phase polymerization process and in particular in the fluidized-gas phase process, the individual particulate materials as such should preferably have the following characteristics before being deposited on or introduced into the catalyst precursor:

specific gravity of about 0.9 to 1.5 g / cm ³ bulk density of about 0.081 to 0.567 g / cm ³ , preferably about 0.243 to 0.567 g / cm 3, and an external void volume of about 0.8 to 5.0 cm / g.

The volume of the outer cavities is a measure of the roundness of the particles and the effectiveness of the coating.

Examples of polymeric organic carrier materials that may be used include polyolefin plastics such as homopolymers and copolymers of monoolefins and C 2 -C 8 polyenes such as polyethylene, polypropylene, polybutene, poly (4-methylpentene), polystyrene and polydienes, and copolymers % of ethylene and propylene which form together or which form with monoolefins and / or polyenes of 4 to 8 carbon atoms.

The organic support material must be chemically inert to all components of the polymerization reaction system in which it is used. The organic carrier is used in an amount of about 60 to 95% by weight, preferably about 65 to 90% by weight, together with about 5 to 40% by weight, preferably about 10 to 35% by weight, of a transition metal catalyst precursor, in the manufacture of carrier materials. compositions of the invention.

The process for the production of the olefin polymerization catalyst composition used in the fluidized bed polymerization process of the present invention is characterized in that it is mixed with the blades at high speed in a finisher

(a) 50 to 95% by weight of solid inert organic particles of polyolefin plastic carrier material having an average particle size of 0.05 to 0.35 mm, a melting point of 70 to 170 ° C and a specific gravity of 0.9 to 1.5 g / cm ³ a

b) 5-50% by weight of particulate transition metal catalyst precursor of Group IVa, Va or Via of the Periodic Table of the Elements, for low pressure olefin polymerization, a precursor of a Ziegler or Ziegler-Natta type high activity catalyst, while stirring continue under conditions of friction releasing heat for a sufficient period of time,

Ί

(a) the particles of the carrier material soften but do not mix with each other; and

b) the catalyst precursor particles are firmly anchored and / or adhered to said particles, a) without causing a deterioration in the chemical nature of particles a) or particles b).

In the actual production of the catalyst composition of the invention, it is not required to use a reducing agent, i.e., activating the amount of organometallic compound, until the catalyst precursor is introduced into the bed used in the polymerization process.

The process itself is usually carried out by feeding the required amount of organic carrier particles and particles of a precursor composition which is a transition metal compound of Group IVa, Va or Via of the Periodic Table of Elements to one another or sequentially over a period of time into a finishing apparatus equipped with blades of high rotation speed. The device is a substantially horizontal mixing chamber of cylindrical shape, having a mixing volume of about 1 to 150 liters and having a motor-driven shaft which passes through the chamber, a plurality of arms are placed on the shaft and the device is equipped with squeegees. Depending on the length of the unit, about 4 to 20 arms can be attached to the shaft. Usually two sets of squeegees are used, each of which is at one end of the shaft.

The finishing device may be water-cooled and equipped with a dispensing opening and a drain line, typically operating under gravity dosing. The motor that drives the shaft and vanes is able to process a batch of carrier and precursor material at a blade discharge rate of at least 3.2 to 19.0 m / s, preferably 12.7 to 17.8 m / s. The finishing device may operate in a batch or continuous manner.

Thus, the particulate materials are mixed with each other for a sufficiently long time and at a sufficiently high temperature that the organic support particles soften and the catalyst precursor material particles are anchored thereon and / or adhered to the softened support materials, but under such time and temperature conditions that avoids chemical decomposition of any of these particulate materials. The temperature used in the mixing operation is essentially due to the frictional heat generated during the mixing operation. The temperature must be controlled so as to avoid bonding between the individual carrier particles. There is no need to add additional heat to the blended mixture, and cooling of the blended mixture may be used to remove the evolution heat. The temperature rise can also be controlled by controlling the speed of the blades to empty, which regulates the heat release by friction.

Stirring of the two particulate materials is continued until an adhesion efficiency of about at least 45% by weight, preferably at least 75 to 90% by weight, is achieved. This may take about 5 to 100 minutes, depending on the size of the handle being processed. As used herein, adherence efficiency means a percentage by weight of the total amount of catalyst to be charged to the support.

Upon completion of the mixing operation, the mixed particles are removed and cooled to room temperature. The resulting particles having precursor particles firmly attached to the carrier particles are substantially the same size and shape as the original carrier particles.

Fluidized bed reactors suitable for the continuous production of polymers from olefins have already been described and are well known in the art. Fluidized bed reactors suitable for this purpose are described, for example, in U.S. Patent Nos. 4,302,565 and 4,370,456, which are referred to herein as prior art. The patents also disclose catalyst compositions suitable for the production of such polymers.

Hydrogen can be used as a chain transfer agent to control the melt index of the polymers produced in the process. Generally, the reaction mixture contains hydrogen in an amount sufficient to produce, wherein the molar ratio of hydrogen to monomer is 0.01: 1 to 0.5: 1. In addition to hydrogen, other chain transfer means can be used to control the melt index of the polymer produced.

Of course, the gaseous reaction mixture should be substantially free of catalytic poisons such as moisture, oxygen, carbon monoxide, carbon dioxide, acetylene, and the like.

The polymerization process is generally carried out at a temperature of about 50 to 100 ° C, preferably 70 to 90 ° C, at a pressure of about 687 to 2748 kPa, preferably about 1030 to 2061 kPa, as the feed monomer and diluent feed. Since the polymerization reaction is exothermic, a heat exchanger or other means in the recirculated gas line is used to remove excess reaction heat.

In order to maintain a viable fluidized bed, the gas velocity on the surface of the gaseous reaction mixture through the bed must exceed the minimum flow rate required for fluidization and is preferably at least 60.9 mm per second above the minimum flow rate. Typically, this gas velocity does not exceed 1.52 m / s, and in particular, a velocity not greater than 762 mm / s is sufficient.

If desired, the supported catalyst catalyst precursor composition may be partially activated prior to introduction into the polymerization reactor. The resulting product is free-flowing solid particles of material whose activation is completed by the addition of an activator compound, which may be the same or different from said activator compound.

Optionally, the precursor carrier catalyst composition can, if desired, be fully activated in the polymerization reactor without any prior activation outside the reactor, in the manner described in U.S. Patent No. 4,383,095, the disclosure of which is incorporated herein by reference.

The partially activated or completely non-activated precursor composition of the supported catalyst and the required amount of activator compound required to fully activate the precursor composition are preferably fed to the reactor via a separate feed line. The activator compound may be sprayed in the reactor as a solution thereof in a hydrocarbon solvent such as isopentane, hexane or mineral oil. This solution typically contains from about 2 to 30% by weight of the activator compound. The activator compound is added to the reactor in an amount sufficient to provide a molar ratio of all activator metal to transition metal of from about 10: 1 to 400: 1, preferably from about 50: 1 to 150: 1.

In the continuous gas phase fluidized bed process herein, a separate portion of the partially activated or completely non-activated precursor composition of the supported catalyst is continuously fed into a reactor with separate portions of the activator compound needed to fully activate the partially activated or fully non-activated precursor composition, during a continuous polymerization process to replace the active catalyst that is consumed during the reaction.

Production under polymerization conditions and with the catalyst composition described herein allows continuous polymerization of olefin monomers individually or in admixture in a fluidized bed to form solid olefin polymers in particulate form without excessive contamination of the reactor. The term continuous polymerization is used herein to denote the ability to not polymerize for a week, i.e., for at least 168 hours, and usually exceeds 1000 hours without contaminating the reactor due to large polymer agglomeration.

The following examples are intended to illustrate the compositions and method of manufacture of the present invention and are not intended to limit the scope of the invention.

The properties of the catalyst compositions and polymers produced are determined by the following test methods:

Specific weight

It is determined according to the American standard ASTM D 792. The discs are made and conditioned for 1 hour at 100 ° C to achieve equilibrium crystallinity. Specific gravity measurements are then performed on a gravity column to determine density.

Productivity

A sample of the plastic produced is burned and the% ash weight is determined. Since the ash essentially consists of a catalyst, the productivity is thus the weight of the polymer produced in grams per weight of total catalyst consumed in grams. The amount of metals and halides in the ash is determined by elemental analysis.

Average particle size

It is calculated from the sieve analysis data measured according to ASTM D1921, method A, using a sample weighing 30 to 200 grams. The calculation is based on the weight of the fractions retained on the mesh.

Bulk density

The plastic is filled through a 9.5 mm diameter funnel into a 100 ml graduated cylinder to the 100 ml mark without shaking the cylinder and determining the weight difference.

Volume of external cavities

The liquid wicking technique is used to measure the volume of internal cavities (IW). The volume of external cavities (EW) is then calculated from:

EW - specific gravity - specific gravity of plastic

IW

In connection with metal groups, reference is made to metal groups according to Mendeleyev's Periodic Table of Elements.

Examples

Catalyst precursor composition

The catalyst precursor composition used in the examples below is a bead composition having an average particle size in the range of about 2 to 50 microns. The precursor composition, when used with activator compounds, is a highly active catalyst for the polymerization of ethylene. It is prepared from titanium tetrachloride as a transition metal compound, magnesium chloride as a complexing carrier and tetrahydrofuran as a complexing carrier, and tetrahydrofuran as a complexing electron donor according to the procedure disclosed in Canadian Patent No. 1,144,300, which is disclosed as prior art. This precursor composition chemically conforms to the composition of the formula

Mg TiCl Ithf1 ^y pL Jq m wherein m is 5-200, p is - 13 to - 403, q is from 0 - to - 3.0, and

THF means tetrahydrofuran.

Carrier material

The carrier used in these examples are solid particles formed by high pressure polyethylene of low specific gravity having a melting point of 95 ° C, specific gravity

3 3

0.93 g / cm @ 2, bulk density 0.355 g / cm @ 2, and external void volume 1.39 cm / g (internal void volume = 0.29 cm @ ³ / g). The particle size distribution of the carrier is such that no particles have a size below 0.09 mm. The particles have a size in the range of 0.09 to 0.15 mm.

Final treatment g a batch (35% by weight) of the catalyst precursor and 130 g (65% by weight) of the support are introduced at 25 ° C and under an inert nitrogen atmosphere and in a batch process to a final treatment apparatus of 102 mm length and 152 diameter. mm having an internal volume of about 1 liter. These devices are closed and the four-blade shaft is started at a speed of 6.3 m per second. The temperature of the stirring shaft rises to 100 ° C due to vigorous stirring and heat friction. The shaft speed is then reduced, after about 20 minutes, to 5.3 m per second to maintain a mixed material temperature of about 100 ° C. After final treatment, the batch is held at 100 ° C for a total of 30 minutes, the shaft is stopped, and the final material is then removed from the final processing apparatus. The resulting material is in the form of particles having an average size of about 100 microns.

The final product electron diffraction spectroscopy (EDS) C1 shows that each particle essentially consists of a carrier core uniformly coated with a precursor composition.

Polymerization reactions

The final catalyst precursor produced as described above is used to terpolymerize ethylene (C ₂ ), propylene (C 2) and 1-hexene (Cg) in a fluidized bed gas phase process in a device substantially described in US Patent Nos. 4 359,561 and 4,363,904 and a bed volume of about 198.2 liters. The reactor is operated at a temperature of 85 ° C in a space and time yield of 3.5 to 5.0 at a partial pressure of 50 to 50 psi of ethylene and a feed gas and a Cg at a molar ratio of C ₂ : C _{3 of} 16: 1 and a ₂ : Cg molar ratio of 11: 1. Triethylaluminium is used as the activator compound, and the Al: Ti molar ratio used is 35:50. The activation is carried out in a reactor. The activator is fed to the reactor as a 5% by weight solution in the hydrocarbon solvent at a rate of about 100 ml / h.

Catalyst dosing and reaction progress are smooth and continuous, as shown by continuous operation of the reactor for a period of time equal to or greater than 2 days without clogging the catalyst dosing device or forming platelets or lumps of polymer therein. 3 Produced polymer is a terpolymer having a specific gravity of 0.918 g / cc, a melt index of 48 and a bulk specific gravity of 0.285 g / ^cc. The polymer is recovered from the reactor at about 11.3 kg per hour at a productivity level of about 1,000,000 g of polymer per g of titanium in the catalyst.

Comparison of polymerization reactions

The catalyst precursor in the final untreated and unadjusted form was used in an attempt to produce an ethylene-1-butene copolymer at a ratio of from 0.30 to 0.32, at a specific weight of 0.918 to 0.922 g / cm 2. This is a simpler polymerization process than a terpolymerization process using a finely prepared precursor catalyst composition.

The reaction is carried out in a reactor system which is the same as that used for the terpolymerization reaction. The reactor was allowed to operate at 85 ° C in a space / time yield of 2.3 at a total reaction pressure of 14 psig. Triethyl aluminum was used as the activator compound, using a molar ratio of aluminum to titanium of 65. The activator was charged to the reactor as a 10% by weight solution in a hydrocarbon solvent.

However, the reactor must be shut down after operating for less than 24 hours. Operation is very unstable and leads to the formation of polymer coatings and platelets on the reactor walls. The formation of coatings and platelets is caused by the migration of the catalyst to the reactor walls. Here, coatings, wafers and lumps are formed from the catalyst-enriched polymeric materials. This unstable reaction operation is also characterized by a large temperature drop (about 10-20 ° C) and persistent problems due to clogging of the catalyst feed device.

Claims (7)

Multi-component catalyst composition of the Ziegler or Ziegler-Natta type, characterized in that it consists of: (a) 50 to 95% by weight of solid inert particles of an organic carrier material based on polyolefin plastic having an average particle size of 0.05 to 0.35 mm, a melting point of 70 to 170 ° C and a specific gravity of 0.9 to 1.5 g / cm ³ a b) 5 to 50% by weight of particulate catalyst precursor consisting of a Group IVa, Va or VIa transition metal compound for low pressure olefin polymerization, wherein the catalyst precursor particles are adhered to the organic support material particles. 2. A composition according to claim 1 wherein the carrier material is polyethylene plastic. 3. A composition according to claim 1 wherein the carrier material is polypropylene plastic. 4. A composition according to any one of Claims 1 to 3 comprising (a) the catalyst precursor referred to in point 1; and b) an activating amount of an organometallic compound acting as a reducing agent. 5. The composition according to claim 4, wherein the reducing agent is based on a metal compound of Group Ia, IIa or IIIa of the Periodic Table of the Elements. 6. A composition according to claim 4 or 5, wherein the compounds a) and b) are present in an atomic ratio of 10: 400, based on the original metal content of the compounds. 7. A process for the production of a catalyst composition as claimed in claims 1 to 6, for the polymerization of olefins used in a fluidized bed polymerization process, characterized in that it is mixed with vanes at a high speed in a finishing apparatus. (a) 50 to 95% by weight of solid inert organic particles of carrier material having an average particle size of 0.05 to 0.35 mm, a melting point of 70 to 170 ° C and a specific gravity of 0.9 to 1.5 g / cm; and (b) from 5 to 50% by weight of particulate catalyst precursor consisting of a Group IVa, Va or Via transition metal compound of the Periodic Table of the Elements, for low pressure olefin polymerization, a high activity Ziegler or Ziegler-Natta type catalyst precursor; stirring is continued under heat-releasing friction conditions for a sufficient period of time, (a) the particles of the support material soften but do not mix with each other; and (b) the catalyst precursor particles are firmly anchored and / or adhered to particles (a) without causing deterioration in the chemical nature of particles (a) or (b).