JPH05105718A - Catalyst composition and process for polymerization of polymer having polymodal molecular weight distribution - Google Patents

Abstract

PURPOSE: To efficiently obtain the subject compsn. useful for a high density PE film by bringing an Mg compd., a Zr compd., a Ti compd. and a V compd. into contact with a solid porous support and further adding the Ti compd. and the V compd. prior to the Zr compd.

CONSTITUTION: A compd. selected from a group consisting of an Mg compd. such as methylmagnesium bromide (A), a Zr compd. such as dicyclopentadienylzirconium halide (B), a Ti compd. such as titanium halide (C), a V compd. such as vanadium halide (D) and a mixture of them is brought into contact with a solid porous support such as silica containing an active OH group and, further, the component C and/or the component D are added prior to the component B to obtain the objective compsn. At least one 2-10C α-olefin is polymerized in the presence of this compsn. to obtain a polymer having multi-mode mol.wt. distribution.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

The present invention relates to a catalyst precursor composition; a catalyst composition; and a method of polymerizing an alpha olefin to produce a polymer having a multimodal molecular weight distribution. More particularly, the present invention relates to catalysts and methods of preparing the catalysts to produce high density polyethylene (HDPE) having a multimodal molecular weight distribution. The present invention also relates to an olefin polymerization process for producing a polymer having a multimodal molecular weight distribution under steady state polymerization conditions in a single polymerization reactor using the catalyst of the present invention.

Various methods have been proposed for producing polymers having a multimodal molecular weight distribution. The term "multimodal molecular weight distribution" refers to two or more peaks when the molecular weight is plotted as a function of the polymer fraction with a given molecular weight, as obtained by gel permeation chromatography (GPC) analysis of the polymer. It means that it can be easily recognized. One such process known to us uses a tandem reactor operating in series, in the first reactor, in the presence of a catalyst and substantially no hydrogen as a chain transfer agent, to produce olefins. Polymerize. The product is transferred to a second downstream reactor where a relatively large amount of hydrogen is present to carry out the polymerization. The first reactor produces high molecular weight components in the final polymer product and the second reactor produces low molecular weight components. The process for producing such multimodal molecular weight distribution polymers is expensive, cumbersome, and time consuming.

The present invention seeks to provide an olefin polymerization catalyst capable of producing a polymer having a multimodal molecular weight distribution under steady state polymerization conditions in a single polymerization reactor.

The present invention provides an olefin polymerization catalyst precursor composition comprising i) a magnesium compound, ii) a zirconium compound, and iii) a titanium compound and / or a vanadium compound, which are supported on a porous carrier.
However, the titanium compound and / or the vanadium compound is added before the zirconium compound during the preparation of the catalyst precursor.

The catalyst precursor is supported on a carrier. The carrier material used in the present invention is generally an inorganic solid, granular porous material. The carrier material may be an inorganic material such as silicon and / or aluminum oxide. The carrier material is used as a dry powder with an average particle size of 1 to 250 microns, preferably 10 to 150 microns. The carrier material is also porous and has a surface area of at least 3 square meters / gram, preferably at least 50 square meters / gram. The carrier material should be dry, that is to remove absorbed moisture. The drying of the carrier material is carried out at a temperature of 100 ° to 1000 ° C, preferably about 60
It can be carried out by heating to 0 ° C. When the support is silica, the support is heated to a temperature of at least 200 ° C, preferably 200 ° to 850 ° C, most preferably about 600 ° C. The support material must contain at least some active hydroxyl (OH) groups to produce the catalyst composition of the present invention. "Active OH
The term "group" means a hydroxyl group that chemically reacts with an alkyl metal compound such as alkyl magnesium and / or alkyl aluminum.

In the most preferred embodiment, the support is flushed with nitrogen and used at about 600 ° C. to obtain a surface hydroxyl concentration of about 0.7 mmol / gram prior to use in the first catalytic synthesis step. It is silica dehydrated by heating for 16 hours. The most preferred embodiment of the silica is high surface area, amorphous silica (surface area = 300 square meters / gram; pore volume = 1.65 cubic centimeters / gram), which has a W. R. Gra
Cevis and Company DavisonChe
medical Division to Davison 9
52 or Davison 955 is a commercially available substance. The silica is in the form of spherical particles as obtained by spray drying.

The carrier material is suitably a slurry in an organic solvent and the resulting slurry is contacted with at least one magnesium compound. A solvent slurry of carrier material is prepared by introducing the carrier material into the solvent, preferably with stirring, and heating the mixture to a temperature of 50 ° to 90 ° C, preferably 50 ° to 85 ° C. Next, the slurry is brought into contact with the magnesium compound while continuing heating at the above temperature.

The magnesium compound has the formula Mg (OR) ₂ , R ¹ _m MgR ² _n or R ³ _k MgX _(2-k) (wherein R, R ¹ , R ² and R ³ can be the same or different). Each represents an alkyl group such as C ₂ to C ₁₂ alkyl, preferably C ₄ to C ₈ alkyl, more preferably C ₄ alkyl; k, m and n are
preferably each represents 0, 1, or 2; and X represents a halogen atom, preferably a chlorine atom, provided that m + n is equal to the valence of Mg. Mixtures of the compounds can be used. The magnesium compound must be soluble in the organic solvent and capable of adhering to the surface of the carrier containing active OH groups. Suitable magnesium compounds are Grignard reagents such as methyl magnesium bromide, chloride or iodide, ethyl magnesium bromide, chloride or iodide, propyl magnesium chloride,
Bromide or iodide, isopropyl magnesium chloride, bromide or iodide, n-
Butyl magnesium chloride, bromide or iodide, isobutyl magnesium chloride, bromide or iodide; magnesium methoxide, magnesium ethoxide, magnesium propoxide, magnesium butoxide, magnesium pentoxide, magnesium hexoxide, magnesium heptoxide,
Magnesium alkoxides such as magnesium octoxide; dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium,
Dialkylmagnesium compounds such as dipentylmagnesium, dihexylmagnesium, diheptylmagnesium, dioctylmagnesium, dinonylmagnesium, methylethylmagnesium, methylpropylmagnesium, methylbutylmagnesium, or propylbutylmagnesium, where the alkyl groups can be the same or different. ); And magnesium dihalides such as magnesium dichloride. Dibutylmagnesium has been found to be particularly preferred in one aspect of the invention.

Then, optionally, at least one organic compound can be added to the slurry. Suitable organic compounds include formulas, ROH alcohols; formulas, RC
O-R 'ketones; Formulas, esters of RCOOR ¹ ;
Or an acid of the formula RCOOH; or an organic silicate of the formula Si (OR) ₄ , wherein R and R ¹ can be the same or different and each is linear or partial of 1 to 12 carbon atoms. Represents a branched or cyclic alkyl group such as methyl, ethyl, propyl, butyl, isobutyl, cyclopropyl, decyl or dodecyl). Each organic compound R can also be a mixture of any of the above alkyl groups. Alcohols such as 1-butanol are preferred.

Next, the titanium compound and / or
Alternatively, it is appropriate to add the vanadium compound and heating of the mixture is continued at the abovementioned temperatures, ie 50 to 90 ° C, preferably 50 to 85 ° C. Titanium or vanadium compounds suitable for use in the present invention are compounds soluble in the organic solvent used in the synthesis. Examples of such compounds are titanium halides, titanium oxyhalides or mixtures thereof such as titanium tetrachloride or titanium oxytrichloride; vanadium halides, vanadium oxyhalides or mixtures thereof such as vanadium tetrachloride or vanadium oxytrichloride; and titanium. Or a vanadium alkoxide (wherein the alkoxide moiety comprises a branched or unbranched alkyl group of 1 to 20, preferably 1 to 6 carbon atoms).
Titanium compounds, especially tetravalent titanium compounds, are preferred. The most preferred titanium compound is titanium tetrachloride. However, if only vanadium alkoxides are used in this step of the catalytic synthesis, without any other titanium or vanadium compounds containing chlorine (Cl) or bromine (Br), to produce an active catalyst, The vanadium alkoxide must be chlorinated or brominated by methods known to those skilled in the art.

The titanium compound or vanadium compound can be used separately or a mixture of the titanium compound or vanadium compound can be used, and the titanium compound or vanadium compound which can be contained is usually subject to restrictions. I can't. Any titanium or vanadium compound that can be used alone can also be used with other titanium or vanadium compounds.

It is then expedient to introduce at least one zirconium compound into the slurry, preferably with a promoter. The zirconium compound has the formula Cp _m ZrY _n X _(2-n) (wherein Cp represents a cyclopentadienyl group; m represents 1, 2 or 3; Y and X may be the same or different; Halogen atoms, especially chlorine atoms,
Represents a C ₁ to C ₆ alkyl group or a hydrogen atom;
And n represents 0 or 1). Suitable zirconium compounds are dicyclopentadienyl zirconium dihalides or dicyclopentadienyl zirconium monoalkyl monohalides (wherein the halide atom is chlorine,
Bromine or iodine is preferably chlorine, and the alkyl group is C ₁
To C ₆ alkyl group). It is also possible to use mixtures of the zirconium compounds. In one aspect of the invention dicyclopentadienyl zirconium dichloride is especially preferred.

The accelerator has the formula: Or

[0014]

(In the formula, m represents an integer of 3 to 50;
n represents zero or an integer of 1 to 50; and R is a linear, branched or cyclic C ₁ to C ₁₂ alkyl group,
For example methyl, ethyl, propyl, butyl, isobutyl, cyclohexyl, decyl or dodecyl)
Is at least one aluminoxane compound having

Each aluminoxane compound can contain different R groups and it is also possible to use mixtures of said aluminoxane compounds. Methylaluminoxane is a particularly preferred accelerator in one aspect of the invention. The promoter is used to impregnate the surface of the support with the zirconium compound. Without wishing to be bound by any operability theory, it is believed that the promoter allows the zirconium compound to adhere to the support surface. The amount of promoter is such that it promotes the attachment of the total amount of zirconium compound to the carrier. In a preferred embodiment, the amount of promoter is such that all of the zirconium compound is deposited on the surface of the support and leaves substantially nothing in the solvent. The slurry is stirred at the above temperature for about 1 to about 5 hours, and the solvent is removed by filtration or vacuum distillation so that the temperature does not exceed 90 ° C. All catalyst synthesis steps are about 50 to about 90 ° C., preferably about 50 to about 8 since elevated temperatures appear to destroy titanium as the active polymerization site.
It must be carried out at the said temperature of 5 ° C. For example, it is believed that holding a mixture of all of the above compounds in a solvent at 115 ° C for several hours destroys titanium as the active polymerization site.

Suitable organic solvents are at least partially soluble in all reactants used according to the invention, ie magnesium compounds, titanium compounds and / or vanadium compounds, zirconium compounds, promoters and any organic compounds, and A substance that is liquid at the reaction temperature. Preferred organic solvents are benzene, toluene, ethylbenzene or xylene. The most preferred solvent for one aspect of the invention is toluene. Prior to use, eg silica gel and / or to remove water, oxygen, polar compounds and other substances which can adversely affect the catalytic activity.
Or the solvent should be purified by percolation through a molecular sieve.

In the most preferred embodiment of the synthesis of this catalyst, some excess of the reactants in solution may react with other synthetic chemicals and precipitate on the outer surface of the support.
All catalytic synthesis reactants, i.e. magnesium compounds, in an amount sufficient to physically or chemically attach to the surface of the support,
It is important to add zirconium compounds, titanium compounds and / or vanadium compounds, accelerators and optional organic compounds. The drying temperature of the support affects the number of sites on the support surface available to the reactants-i.e.,
Higher drying temperatures reduce the number of sites. Thus, the exact molar ratio of the magnesium compound, zirconium compound, titanium compound and / or vanadium compound, the promoter and any organic compound to the hydroxyl group is changed, leaving no slight excess in the solution, In-situ measurements must be made to ensure that each reactant, which only adheres to the surface of the carrier from the solvent, has been added to the solution. Therefore, the following molar ratios are merely intended to serve as a rough guide, and the exact amount of catalytic synthesis reactants in this embodiment must be controlled by the functional constraints described above. That is, it should not exceed the amount that can be attached to the surface of the carrier. Excessive amounts added to the solvent should be avoided as excess amounts may react with other reactants, resulting in precipitation of the outer surface of the carrier which is detrimental to the synthesis of the catalyst. .. The amount of various reactants that is not greater than the amount adhering to the surface of the carrier can be determined by any conventional method, such as a reactant such as a magnesium compound in the solvent slurry of the carrier until the magnesium compound is detected as a solvent solution while stirring the slurry. Can be measured by adding.

For example, in the case of a silica support heated to about 200 to about 850 ° C., the amount of magnesium compound added to the slurry was such that the molar ratio of Mg to hydroxyl groups (OH) on the solid surface dried the support material. From about 0.1 to about 3, preferably from about 0.5 to about 2, depending on temperature;
More preferably, the amount will range from about 0.7 to about 1.5, most preferably from about 0.8 to about 1.2. The magnesium compound dissolves in a solvent to form a solution. For the same silica support that has been subjected to the above heat treatment, when a titanium compound is used in the synthesis, the molar ratio of Ti to OH groups on the surface of the support is about 0.1: 1 to about 10: 1, preferably about 1: 1. 1
In the case of using a vanadium compound for the synthesis, V: O
The molar ratio of H groups is from about 0.1: 1 to about 10: 1, preferably about 1: 1 and when a mixture of titanium and vanadium compounds is used, the sum of V and Ti to the OH of the solid support surface. The molar ratio of groups is from about 0.1: 1 to about 1
It is 0: 1, preferably about 1: 1. The amount of promoter added to the slurry is such that the molar ratio of Al obtained from the promoter to OH groups on the surface of the solid support is from about 0.1 to about 3, preferably from about 0.5 to about 3 depending on the temperature at which the support material is dried. 2, more preferably about 0.7 to about 1.5, and most preferably about 0.8 to about 1.2. The molar ratio of Ti: Zr or V: Zr in the final catalyst composition is about 1:
1 to about 50: 1, preferably about 10: 1 to about 2
It is 0: 1. When any organic compound is used in the synthesis, the amount is such that the compound reacts with substantially all of the magnesium compound deposited to the point on the support surface during catalyst synthesis.

It is also possible to add the various reactants in excess of the amount deposited on the support surface, and then to remove any excess reactants, for example by filtration and washing. However, this alternative is less desirable than the most preferred embodiment described above. Thus, in a preferred embodiment, the amount of magnesium compound, zirconium compound, thione compound and / or vanadium compound, promoter and any organic compound used in the synthesis is not greater than the amount that can be attached to the carrier. ..
The exact molar ratio of Mg to Zr, Ti and / or V and the exact molar ratio of Mg, Zr, Ti and / or V to the hydroxyl groups of the carrier may thus change (for example by the carrier drying temperature) and thus You have to measure on the spot.

The resulting solid, referred to herein as the catalyst precursor, is mixed with the catalyst activator. The activator is a mixture of co-catalysts of conventional olefin polymerization catalysts used to activate titanium or vanadium sites and activators suitable for activating zirconium sites.

The usual cocatalyst used here is Fish.
Catalog Number 5-702-1, published by er Scientific Company
0 (1978) Periodic Table IB, IIA, II
Any one or a mixture of any of the materials commonly used to activate Ziegler-Natta olefin polymerization catalyst components that include at least one compound of Group B, IIIB, or IVB elements. Examples of such cocatalysts are alkylmetals, metal halides, alkylmetal halides and alkylmetal halides such as alkyllithium compounds, dialkylzinc compounds, trialkylboron compounds, trialkylaluminum compounds, alkylaluminum halides and hydrides, and tetraalkylgermanium. It is a compound. It is also possible to use mixtures of said cocatalysts. Specific examples of useful cocatalysts include n-butyllithium, diethylzinc, di-n-propylzinc, triethylboron, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, ethylaluminum dichloride, dibromide. And dihydride, isobutylaluminum dichloride, dibromide and dihydride,
There are diethylaluminum chloride, bromide and hydride, di-n-propylaluminum chloride, bromide, and hydride diisobutylaluminum chloride, bromide and hydride, tetramethylgermanium, and tetraethylgermanium. Preferred organometallic cocatalysts for this invention are the Group IIIB element alkyl metal and dialkyl metal halides having from 1 to about 20 carbon atoms per alkyl group. More preferably, the cocatalyst is a trialkylaluminum compound having 1 to 6, preferably 1 to 4 carbon atoms per alkyl group. The most preferred cocatalyst is trimethylaluminum.
Other co-catalysts that can be used here are Steve
ns et al., U.S. Pat. No. 3,787,384, col. 4, line 45 to col. 5, line 12, and Strobe.
U.S. Pat. No. 4,148,754, column 4, fifth.
It is disclosed from the 6th line to the 5th column and the 59th line, both of which are incorporated herein by reference in their entirety.
The cocatalyst is used in an amount that is at least effective in promoting the polymerization activity of the titanium and / or vanadium moieties of the catalyst of the present invention. Higher weight ratios of cocatalyst to V or Ti in the catalyst precursor, such as 15: 1, 30: 1, 50: 1 or higher are also suitable and often give satisfactory results, but in the catalyst precursor It is preferred to use at least about 10 parts by weight of cocatalyst per 1 part by weight of V or Ti.

Suitable activators for activating the zirconium sites are different from the conventional activators mentioned above. The zirconium activator controls R ₃ Al (where R is C
₁ alkyl -C ₁₂₎ and a linear and / or cyclic aluminoxane species prepared another by the action of water.
As known to those skilled in the art, the rate of addition of water to R ₃ Al,
R ₃ concentrations of Al and water, as well as the performance of the reaction temperature catalysts, for example the catalytic activity, it is possible to control the molecular weight and molecular weight distribution of the polymers produced with a catalyst to activate the zirconium sites zirconium sites activator.

In the case of linear aluminoxane, the activator for the zirconium moiety is of the formula Where n is 0, 1, 2 or 3 and / or in the case of a cyclic aluminoxane, the formula

[0025]

(Where m is an integer of 3 to 50), aluminoxane is preferable, and in both linear and cyclic aluminoxane, R is the same or different and has 1 to 12 carbon atoms. It is a linear, branched or cyclic alkyl group such as methyl, ethyl, propyl, butyl, isobutyl, cyclopropyl, decyl or dodecyl. Any aluminoxane compound can contain different R groups and it is also possible to use mixtures of the aluminoxane compounds.

The most preferred zirconium site activator is methylaluminum oxane. Since the commercially available methylaluminum oxane appears to contain trimethylaluminum, in the most preferred embodiment the addition of the commercially available methylaluminum oxane to the catalyst precursor activates both zirconium and titanium and / or vanadium sites. Is enough for

The catalyst precursor of the present invention is prepared at a time when water, oxygen, and other catalyst poisons are substantially absent. The catalyst poisons can be eliminated by any well known method during the catalyst manufacturing process, for example by carrying out the preparation in a nitrogen, argon or other inert gas atmosphere. Inert gas purging can serve the dual purpose of eliminating extraneous foreign matter during manufacture and eliminating undesirable reaction byproducts resulting from the preparation of catalyst precursors. Purification of the solvent used for catalyst synthesis is also effective in this respect.

The precursor can be activated in situ by adding the precursor and activator mixture separately to the polymerization medium. It is also possible to mix the precursor with the activator before introducing it into the polymerization medium, for example at a temperature of about -40 to about 100 ° C for up to about 2 hours.

Olefins, especially alpha olefins,
The catalyst prepared according to the present invention is used to polymerize by any suitable method. Such methods include polymerization methods carried out in suspension, solution or gas phase. Gas phase polymerization reactions, such as those carried out in stirred bed reactors, especially fluidized bed reactors, are preferred.

Due to the unique properties of the catalysts of the present invention, to control the molecular weight of the polymer product during the polymerization reaction,
By design, a relatively small amount of hydrogen is added to the reaction medium. A typical hydrogen (H ₂ ): ethylene (C ₂ =) gas phase molar ratio in the reactor is about 0.01 to about 0.2, preferably about 0.02 to about 0.05. The reaction temperature is about 70 to about 100 ° C., the residence time is about 1 to about 5 hours, and the amount of olefin used in the reactor is such that when ethylene is polymerized alone or with higher alpha olefins, Ethylene partial pressure of about 50 to about 25
The amount is 0 psi. Under such polymerization operation conditions, a polymer having a multimodal molecular weight distribution can be obtained. Polymerization in the presence of the catalyst of the present invention in a single polymerization reactor results in a polymer having a bimodal molecular weight distribution with polymer chains having a molecular weight ranging from about 1,000 to about 1,000,000. .. Without wishing to be bound by any theory of operability, certain polymerization conditions,
That is, it is considered that the zirconium (Zr) catalyst site produces a relatively short polymer chain having a relatively low molecular weight depending on the amount of hydrogen specified here, so that a bimodal molecular weight distribution is obtained. In contrast, under the same polymerization conditions, titanium (Ti) and / or vanadium (V) catalytic sites produce relatively high molecular weight, relatively long polymer chains. Thus, the polymer product contains two types of polymer chains,
It produces a multimodal molecular weight distribution. The multimodal molecular weight distribution is important because the resin with the molecular weight distribution is relatively easy to process, for example in an extruder, and the resin produces a film with sufficient strength performance.

The molecular weight distribution of the polymer produced in the presence of the catalyst of the present invention, expressed as a melt flow ratio (MFR) value, has a density of about 0.930 to about 0.940 g / cc.
And about 50 to about 300, preferably about 10 for medium density polyethylene (MDPE) products having an I ₂ (melt index) of about 0.01 to about 1 g / 10 min.
It ranges from 0 to about 200. Conversely, the HDPE product produced using the catalyst of the present invention has a density of about 0.940 to about 0.960 g / cc and a flow index (I ₂₁ ) of about 1 to about 100, preferably about 4 to about. 40, M
The FR value is about 50 to about 300, preferably about 100 to about 200. As known to those skilled in the art, for the above flow index values, these MFR values indicate a relatively broad molecular weight distribution of the polymer. This MFR value is also high density polyethylene (HD
PE) shows polymers which are particularly suitable for films and blow molding. Gel permeation chromatography (GPC) traces of polymers prepared using the mixed metal catalysts of the present invention show a broad bimodal molecular weight distribution (MW).
D) is shown. The details of MWD are controlled by the catalyst composition and reaction conditions. A bimodal MWD can be used to obtain the proper balance of mechanical properties and workability.

The catalyst produced according to the present invention has a strong activity,
The polymer can have an activity of at least about 1.0 to about 10.0 kilograms per gram catalyst per 100 psi ethylene for about 1 hour.

The linear polyethylene polymer produced according to the present invention may be ethylene homopolymer or ethylene and 1
One or more copolymers of C ₃ -C ₁₀ alpha-olefins. Thus, not only copolymers having two monomer units but also terpolymers having three monomer units are possible. Specific examples of the polymer include ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene /
1-octene copolymer, ethylene / 4-methyl-1-
There are pentene copolymers, ethylene / 1-butene / 1-hexene polymers, ethylene / propylene / 1-hexene polymers and ethylene / propylene / 1-butene terpolymers. Ethylene / 1-hexene copolymers are the most preferred copolymers polymerized in the process of this invention using the catalysts of this invention.

The polyethylene polymer produced according to the present invention preferably contains at least 80 weight percent ethylene units.

A particularly preferred method of producing the polyethylene polymer according to the present invention is in a fluidized bed reactor. The reactor and the means for operating it are Levin
e., U.S. Pat. No. 4,011,382, Karol et al., U.S. Pat. No. 4,302,566, and Nowli.
U.S. Pat. No. 4,481,301 to N. et al., the entire contents of which are incorporated herein by reference. The polymer produced in the reactor contains catalyst particles as the catalyst does not separate from the polymer.

The invention is illustrated by the following examples.

The properties of the polymers produced in each example and any calculated process parameters were measured by the test methods described below.

Density: ASTM D 1505-Plaques are made and conditioned at 100 ° C. for 1 hour to approach equilibrium crystallinity. Density measurements are then taken in a density gradient column and are reported as grams / cubic centimeter.

Melt Index (MI), I ₂ : AS
TM D-1238 …… Condition E ──Measured at 190 ℃ ──
Described as grams / 10 minutes.

High load melt index (HIMI),
I ₂₁ : ASTM D-1238 ... Condition F--Measured at 10 times the weight used in the melt index.

Melt Flow Ratio (MFR) = I ₂₁ / I ₂ Productivity: A resin product sample is ashed to determine the weight percentage of ash; the ash consists essentially of the catalyst and therefore the productivity is consumed. 3 pounds of polymer produced per pound of total catalyst. The amounts of Ti, Mg, V and Al in the ash are determined by elemental analysis.

Example 1 (Synthesis of catalyst precursor) All operations were performed in a dry nitrogen atmosphere.

Solution (A): 0.317 grams of dicyclopentadienyl zirconium dichloride (Cp ₂ Zr
Cl ₂ ) was transferred to a 100 ml round bottom flask and 50 ml of anhydrous toluene was added. The flask was placed in a 50 ° C. oil bath until a clear solution formed.

Solution (B): 50 ml of anhydrous toluene and 12 ml of methylaluminum oxane (MAO) (4.6% by weight Al in toluene) were placed in a 200 cc pear-shaped flask. The pear-shaped flask was placed in an oil bath set at 50 ° C. Next, add 20 m of solution (A) to the pear-shaped flask.
l was added to give a clear pale yellow solution.

Catalyst Preparation Solution: Davison Che heated at 600 ° C. for about 16 hours while purging with dry nitrogen.
grade 955 silica from the Medical Company 1
0.095 grams was weighed into a 500 cc pear-shaped flask containing a magnetic stir bar. The flask was placed in an oil bath at 80 ° C. and 50 ml of anhydrous toluene was added to the flask. next,
7.2 ml of dibutyl magnesium (0.973 mmol / ml) was added to the silica / toluene slurry.
The flask contents were stirred for 50 minutes. Then 0.80 ml of pure titanium tetrachloride was added to the flask. The slurry turned dark brown and stirring was continued for another 60 minutes. Finally,
The total content of solution (B) was siphoned into a catalyst preparation flask and the slurry was stirred for 60 minutes. After this end, all solvent was removed by evaporation while purging with nitrogen. Catalyst yield is 12.805 dark brown dry powder
It was gram.

Example 2 ( Polymerization Operation) Using the catalyst precursor of Example 1, an ethylene / 1-hexene copolymer was prepared by the following typical procedure.

While slowly purging nitrogen into a 1.6 liter stainless steel autoclave maintained at about 50 ° C., 0.750 liters of anhydrous hexane and 1-
Hexene 0.030 liters and methylaluminum oxane (MAO) 5.1 mmol were charged. The reactor was closed, the stirring speed was set to about 900 rpm, the internal temperature was raised to 70 ° C. and the internal pressure was raised to 8 psi to 11 psi with hydrogen. By introducing ethylene, the pressure is about 1
It was kept at 14 psi. Next, 0.0349 grams of the catalyst precursor of Example 1 was introduced into the reactor while applying excessive ethylene pressure, the temperature was raised and held at 85 ° C. After continuing the polymerization for 60 minutes, the ethylene supply was stopped and the reactor was cooled to room temperature. 110 grams of polyethylene were collected. When the MWD of the polymer was examined by GPC, the results clearly showed that the polymer had a bimodal MWD (Figure 2).

Example 3 (Synthesis of Catalyst Precursor) 191.4 grams of Davison grade 955 silica previously dried at 600 ° C. for 16 hours was purged with nitrogen into a 3 liter four neck round bottom flask equipped with an overhead stirrer. While adding. Toluene (800 ml) was added to the flask and the flask was set to 60.
It was placed in an oil bath maintained at ° C. Next, 129 ml of dibutyl magnesium (1.04 mol heptane solution) was added to the silica / toluene slurry. The solution was stirred for 35 minutes. Further, 15.0 ml of pure TiCl _{4 was} mixed with 50 ml of anhydrous toluene.
It was diluted with ml and added to the flask. The solution was stirred for 60 minutes. Finally, methyl aluminoxane (4.6 wt%
Al) 93 ml and Cp ₂ ZrCl ₂ 2.41 g in 1
In addition to the 25 ml addition funnel, a clear yellow solution was obtained. This solution was added to the silica / toluene slurry and the oil bath temperature was raised to 80-85 ° C.

The slurry was heated for 3 hours. When this was over, the temperature of the oil bath was lowered to 50 ° C., stirring was stopped and the silica was allowed to settle. The supernatant was decanted and the silica washed 3 times with 1500 ml anhydrous hexane. The silica was dried while purging with nitrogen to give about 233 grams of a dry, frosted powder.

Example 4 ( Polymerization Operation) Using the catalyst precursor composition of Example 3, Howlin et al., US Pat. No. 4,481,301
The ethylene / 1-hexene copolymer was prepared in a fluidized bed pilot plant reactor operating substantially according to the method disclosed in US Pat. Steady state operation by continuously withdrawing polymer product from the reactor while continuously feeding catalyst precursor, MAO activator, and reactant gases (ethylene, 1-hexene and hydrogen) to the reactor. was gotten. The operating conditions of the reactor were as follows.

Ethylene 210 psi (C ₆ = / C ₂ =) Steam Molar Ratio 0.039 (H ₂ / C ₂ ) Steam Molar Ratio 0.050 Production Rate 24.9 lbs / hour Catalyst Productivity 3000 grams Polymer / gram Catalyst Residence time 2.5 hours Temperature 90 ° C. MAO supply 270 ml / hour (1.0 wt% Al toluene solution) Polymer had the following properties: Density 0.942 g / cc Flow index (I ₂₁ ) 16 .3 grams / 10 min When the molecular weight distribution of the polymer was examined by GPC, the results clearly showed that the polymer had a bimodal MWD (Figure 3).

[Brief description of drawings]

1 is an industrially produced bimodal polymer (Cai
n Chemicals, Inc. Cai obtained from
n L5005) is a gel permeation chromatography (GPC) chromatograph of the molecular weight distribution.

FIG. 2 is a GPC graph of the molecular weight distribution of a polymer produced using the catalyst and method of the present invention described in Example 2.

FIG. 3 is a GPC graph of the molecular weight distribution of a polymer produced using the catalyst and method of the present invention described in Example 4.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Pradatup Pandran Syrodkar 58873, New Jersey, USA, Jysonson Road, Somerset 52

Claims (13)

[Claims] 1. An olefin polymerization catalyst precursor composition comprising: i) a magnesium compound; ii) a zirconium compound; and III) a titanium compound and / or a vanadium compound; An olefin polymerization catalyst precursor composition in which the titanium compound and / or the vanadium compound is added in advance to the zirconium compound. 2. The precursor composition of claim 1, wherein the carrier contains active OH groups. 3. The magnesium compound has the formula; Mg (OR) ₂ , R ¹ _m MgR ² _n or R ³ _k MgX _(2-k) (wherein R, R ¹ , R ² and R ³ are the same or different. Each represents an alkyl group; X represents a halogen atom; and k, m, and n are m + n is Mg.
The precursor composition of claim 1 or claim 2 having the valency of 0, 1 or 2, respectively. 4. A zirconium compound has the formula: Cp _m ZrY _n X _(2-n) (wherein Cp represents a cyclopentadienyl group; m represents 1, 2 or 3; X and Y are the same or Can be different and each is a halogen atom, C ₁ to C ₆
Represents an alkyl group or a hydrogen atom; and n represents 0 or 1). A precursor composition according to any one of the preceding claims. 5. The precursor composition of any one of the preceding claims, wherein the titanium compound comprises titanium halide, titanium oxyhalide or a mixture thereof and the vanadium compound comprises vanadium halide, vanadium oxyhalide or a mixture thereof. object. 6. A Ti: Zr molar ratio of 1: 1 to 5
A precursor composition according to any one of the preceding claims, which is 0: 1. 7. An alcohol of formula R-OH; formula RCO-R
¹ ketone; formula RCOOR ¹ ester; formula RCOOH
Or an organic silicate of formula Si (OR) ₄ , wherein R and R ¹ can be the same or different and each has 1 to 12 carbon atoms, linear, branched, Or a cyclic alkyl group)). A precursor composition according to any one of the preceding claims. 8. The precursor of any one of the preceding claims; IB, IIA, IIB, II in the Periodic Table of the Elements.
A cocatalyst containing at least one compound of Group IB or Group IVB and a formula: Or (Wherein m represents an integer of 3 to 50; n represents 0 or an integer of 1 to 50; R represents a linear, branched or cyclic C ₁ to C ₁₂ alkyl group) A catalyst activator which is a mixture with a zirconium site activator which is nooxane. 9. A cocatalyst is 1 to 20 per alkyl group.
9. The catalyst composition of claim 8 which is a Group IIIB metal alkyl or dialkyl halide having 4 carbon atoms. 10. A method for synthesizing an olefin polymerization catalyst precursor composition, wherein a magnesium compound; a zirconium compound; and a titanium compound are added to the solid porous carrier.
A method in which a compound selected from the group consisting of vanadium compounds and mixtures thereof; is contacted, and a titanium compound and / or a vanadium compound is added before the zirconium compound. 11. A method of polymerizing at least one C ₂ to C ₁₀ alpha olefin to produce a polymer having a multimodal molecular weight distribution.
Alternatively, a method of carrying out the polymerization in the presence of the supported catalyst composition defined in claim 9. 12. The method of claim 11 wherein the alpha olefin feedstock comprises a mixture of ethylene and at least one C ₃ to C ₁₀ alpha olefin. 13. The method according to claim 1, wherein the hydrogen: ethylene molar ratio is 0.01 to 0.2.
1 or the method of claim 12.