JPH0610212B2 - Method for producing polyolefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an olefin polymer. More specifically, it relates to a method for producing an olefin polymer and a copolymer using a novel catalyst obtained by supporting an organic transition metal compound and a water-modified organoaluminum compound on a finely particulate porous inorganic oxide.

Using a transition metal composition in which an organometallic compound of a transition metal of Groups IVA to VIA of the Periodic Table of Elements is chemically bonded to a substantially chemically inert matrix material as an initiator of an olefinically unsaturated monomer Method is Japanese Patent Publication Sho 51-252
72, 26419.

However, since these catalysts give high molecular weight polymers but their activity is insufficient, the inorganic carrier substances and transition metals remaining in the polymers adversely affect the quality and physical properties of the polymers.

Therefore, in order to improve these problems, it is important to greatly improve the catalytic activity, and some proposals regarding this have been made.

Japanese Patent Application Laid-Open No. 47-17722 and U.S. Pat. No. 3,635,935 describe a method of activating tetraneopentyl titanium which is diffused and deposited on a silica carrier by adding an organoaluminum compound and using it as a catalyst for olefin polymerization. The preferred organoaluminum compound in this case is a dialkylaluminum halide, such as diethylaluminum chloride.

JP The 56-57805 substantially inert matrix material in an organic transition metal compound and the bond represented by R ¹ ₃ organometallic compound represented by M and R ² ₄ ZrXp or R ² ₄ HfXp such as alumina Metal composition (M is Periodic Table II
A Group IB metal, R ¹ and R ² are hydrocarbon groups, or substituted hydrocarbon groups, X is a singly charged anionic or monodentate ligand, if present, and p Is 0, 1 or 2) is used as an initiator to polymerize an olefinically unsaturated monomer. In this case, preferred organometallic compounds include organoaluminum compounds such as triethylaluminum and tributylaluminum. It is also described that the effect can be seen only in a specific order of addition depending on the type of the organoaluminum compound used.

Japanese Patent Publication No. 55-15483 describes a method in which a reaction product of a partially hydrated alumina and a tetra (hydrocarbyl) transition metal compound is hydrogenated with hydrogen and used as a polymerization initiator of 1-olefins.

Although the activity of the catalyst is considerably improved by the above-mentioned improvement of the catalyst, it cannot be said to be sufficient.

As a result of intensive studies to achieve high catalytic activity and improvement in productivity, the present inventors have found that in the polymerization of olefins, it does not substantially contain adsorbed water and has fine surface-active, porous inorganic oxides having a reactive surface hydroxyl group. By using a solid product obtained by catalytically reacting an organic transition metal compound and a water-modified organoaluminum compound as an initiator, it is much higher than when only an inorganic oxide and an organic transition metal compound are catalytically reacted. It is active, and is further disclosed in JP-A-56-578.
The inventors have found that the activity is higher than that in the case of adding the organoaluminum compound described in No. 05, and that the effect is not affected by the order of addition, and thus the present invention has been reached.

That is, the present invention relates to an olefin polymerization catalyst that is substantially free of adsorbed water and has fine particles having a reactive surface hydroxyl group, a porous inorganic oxide, an organic transition metal compound, and a water-modified organic aluminum compound. .

Hereinafter, the present invention will be described in detail.

(1) Inorganic oxide carrier As the inorganic oxide carrier, alumina is particularly preferable, a particle size of 5 to 1000 μ, a specific surface area of 50 to 1000 m ² / g, and a pore volume of 0.2 to 3 ml / g are preferable, and particularly preferable. Is 2
It has an average particle size of 0 to ²⁰⁰ μ, a specific surface area of 100 to 400 m ² / g and a pore volume of 0.5 to 2.5 ml / g.

The inorganic oxide support is treated with hot water for 2 to 50 hours at a temperature in the range of 40 to 100 ° C. for use, then 100
Temperature in the range of up to 1000 ° C., particularly preferably 300 to 6
The adsorbed water is removed by heating at a temperature of 00 ° C.

(2) Organic Transition Metal Compound The organic transition metal compound used in the present invention has the general formula R ¹ _p
MX _4-p (M is a transition metal of Group IVA of the periodic table, R ¹
Is a hydrocarbon group or a substituted hydrocarbon group, X is a halogen, _p
Is an integer of 2 to 4) and specific examples thereof include tetrabenzylzirconium, tetrabenzyltitanium, tetrabenzylhafnium, tetraneopentylzirconium, tetraneopentyltitanium, tetraneoffilzirconium and tetraneo Examples include fil titanium, tetra neophyll hafnium, and tetraallyl zirconium.

(3) Water-modified organoaluminum compound The water-modified organoaluminum compound used in the present invention is
It can be obtained by reacting water with a trialkylaluminum represented by the general formula AlR ² ₃ (wherein R ² represents an alkyl group of 1 to 10), preferably trimethylaluminum and triethylaluminum. The reaction method is not particularly limited, and water may be added to the trialkylaluminum as a liquid, or may be dissolved in a solvent and added dropwise, or a method of causing a catalytic reaction in the form of mist or steam, but particularly preferably, Examples include a method of producing by carefully reacting with a compound containing water of crystallization such as copper sulfate pentahydrate.

The reaction conditions for modifying the organoaluminum compound with water are not particularly limited, but the molar ratio of water to the organoaluminum compound is preferably 0.1: 1 to 2.5: 1, particularly preferably 0.3: 1 to 2: 1. And the reaction temperature is preferably −80 to 100 ° C., particularly preferably −2.
0 to 50 ° C., 5 minutes to 100 hours, particularly preferably 1 to
Process for 50 hours.

The structure of the water-modified organoaluminum compound obtained by such a reaction is very complicated, and probably the general formula Linear aluminoxane and general formula The cyclic aluminoxane (R ² is a hydrocarbon group, and n is an integer from 1 to 50).

In the present invention, the solvent used for the catalytic reaction of the inorganic oxide carrier, the organic transition metal compound, and the water-modified organoaluminum compound is inert, and must be dehydrated and deoxygenated. Examples of the inert solvent include aromatic hydrocarbons such as benzene, toluene and xylene, n-
Saturated aliphatic hydrocarbons such as pentane, n-hexane and n-heptane, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are used.

The amount of the transition metal supported in the solid catalyst of the present invention is preferably 0.05 to 1.0 mmol / g, particularly preferably 0.1 to 0.5 mmol / g.

The reaction between the water-modified organoaluminum compound and the organic transition metal compound and the inorganic oxide carrier is carried out in an appropriate order or by adding them simultaneously.

The ratio of the number of gram atoms of aluminum to the transition metal in the solid catalyst of the present invention is preferably 0.05: 1 to 100: 1, and particularly preferably 0.1: 1 to 25: 1.

Also, since many of the organic transition metal compounds used in the present invention are thermally unstable, it is necessary to keep the reaction temperature sufficiently low in order to prevent decomposition when using such compounds. .

Examples of the olefin used in the present invention include α-olefins such as ethylene, propylene and butene-1.
Not only these homopolymerizations but also copolymerizations can be performed.

As the polymerization or copolymerization method, various polymerization methods such as solution polymerization or slurry polymerization in the presence of an inert hydrocarbon or a liquefied monomer, and gas phase polymerization in the absence of a solvent can be carried out.

The polymerization temperature is room temperature to 300 ° C., and the pressure is atmospheric pressure to 1000.
It can be carried out in the range of atmospheric pressure. Further, the presence of hydrogen in the polymerization system makes it possible to easily control the molecular weight of the polymer produced.

Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In Examples and Comparative Examples, the isotactic index (II) was the boiling amount in a Soxhlet extractor, the solid remaining amount after extraction with n-heptane for 16 hours, and the ether-insoluble portion (IE) was the same in the Soxhlet extractor. The remaining solid amount after extraction with diethyl ether for 8 hours is expressed in% by weight.

Example 1 Preparation of Methylaluminoxane CuSO ₄ .5H ₂ O ₃ 7.5 g (0.15 mol) was suspended in 100 ml of toluene, and a mixed solution of 50 ml (0.52 mol) of trimethylaluminum and 150 ml of toluene was gradually added at 20 ° C. with stirring. Dropped. After completion of dropping, 48 at 20 ° C
The reaction continued for an hour. Next, the reaction solution was passed through to remove solid copper sulfate, and then toluene and unreacted trimethylaluminum were removed under vacuum to obtain 17 g of methylaluminoxane.

Preparation of catalyst High-purity γ-alumina (Catalyst Kasei ACP-1, average particle size of about 60μ, specific surface area of about 300 m ² / g, pore volume of about 0.7 ml
/ G) was treated with hot water for 30 hours and then washed with acetone. This was heated at 450 ° C. for 6 hours in a dry nitrogen atmosphere to remove adsorbed water.

0.75 g of this alumina was suspended in 10 ml of toluene, and 35 mg of methylaluminoxane dissolved in this toluene was suspended.
(0.6 mmol aluminum unit) was added. After stirring this mixture for 30 minutes, 1 ml of a 0.16 M solution of tetrabenzylzirconium dissolved in toluene was added, and the mixture was further stirred for 30 minutes.

The solid catalyst thus prepared contained 0.2 mmol / g zirconium and 0.8 mmol / g aluminum.

Polymerization of Propylene A 2-liter stainless steel autoclave equipped with a stirrer was vacuumed and degassed with nitrogen, and then the above solid catalyst slurry and 500 g of liquid propylene were charged.
With stirring, the temperature was raised to 70 ° C. and polymerization was carried out for 1 hour. After the polymerization was completed, unreacted propylene was removed to stop the reaction, and the polymer was taken out. White / granular polypropylene 235
g was obtained, and the polymerization activity was 1470 g PP / mmol Zr · hr. Further, II of the polymer was 65.8% and IE was 70.8%.

Examples 2 to 6 Preparation of a catalyst and polymerization of propylene were carried out in the same manner as in Example 1 except that the addition amount and the order of addition of methylaluminoxane were changed. The results are shown in Table 1.

Comparative Example 1 A catalyst was prepared and propylene was polymerized in the same manner as in Example 1 except that methylaluminoxane was not added. The results are shown in Table 1.

Comparative Example 2 A catalyst was prepared and propylene was polymerized in the same manner as in Example 1 except that triethylaluminum was used instead of methylaluminoxane. The results are shown in Table 1.

Comparative Example 3 A catalyst was prepared and propylene was polymerized in the same manner as in Comparative Example 2 except that the order of addition of triethylaluminum and tetrabenzylzirconium was changed. The results are shown in Table 1.

Example 7 Preparation of catalyst Heat treatment was carried out in the same manner as in Example 1, 0.38 g of alumina from which adsorbed water had been removed was suspended in 5 ml of toluene, and 18 mg of methylaluminoxane dissolved in toluene (0.
(3 mmol of aluminum unit) was added and the mixture was stirred for 30 minutes, then 0.5 ml of a 0.16 M solution of tetrabenzylzirconium dissolved in toluene was added, and the mixture was further stirred for 30 minutes to obtain a solid catalyst slurry.

Polymerization of ethylene A 2-liter stainless steel autoclave equipped with a stirrer was vacuum degassed and purged with nitrogen, and then 800 ml of n-hexane and the above solid catalyst slurry were charged. While stirring, the temperature was raised to 70 ° C and the ethylene partial pressure was maintained at 4.0 kg / cm ²
Polymerization was carried out for a time. After the polymerization was completed, unreacted ethylene was removed to stop the reaction. The polymer was separated and dried to obtain 175 g of white and granular polyethylene. The polymerization activity was 2190 g PE / mmol Zr · hr.

Comparative Example 4 A catalyst was prepared and ethylene was polymerized in the same manner as in Example 6 except that methylaluminoxane was not added to obtain 78 g of white, granular polyethylene. Polymerization activity is 98
It was 0 g PE / mmol Zr · hr.

Example 8 Preparation of Catalyst By adding tetrabenzyltitanium in place of tetrabenzylzirconium in the preparation of the catalyst of Example 1, 0.2 mmol / g of aluminum and 0.
A solid catalyst containing 8 mmOl / g aluminum was prepared.

Polymerization of Propylene Polymerization of propylene was carried out in the same manner as in Example 1 except that the above solid catalyst containing tetrabenzyltitanium was used as a catalyst. The results are shown in Table 2.

Examples 9 and 10 Preparation of a catalyst and polymerization of propylene were carried out in the same manner as in Example 8 except that the addition amount and the order of addition of methylaluminoxane were changed. The results are shown in Table 2.

Example 11 Preparation of catalyst 0.2 mmol / g hafnium and 0.8 was added by adding tetrabenzyl hafnium instead of tetrabenzyl zirconium in the preparation of the catalyst of Example 1.
A solid catalyst containing mmol / g aluminum was prepared.

Polymerization of Propylene Polymerization of propylene was carried out in the same manner as in Example 1 except that the above solid catalyst containing tetrabenzylhafnium was used as the catalyst. The results are shown in Table 3.

Examples 12 and 13 Preparation of a catalyst and polymerization of propylene were carried out in the same manner as in Example 11 except that the addition amount and the order of addition of methylaluminoxane were changed. The results are shown in Table 3.

Example 14 Preparation of catalyst By adding an organozirconium compound ZrBz _3.2 Cl _0.8 (in the formula, Bz represents a benzyl group) having the following composition instead of tetrabenzylzirconium in the preparation of the catalyst of Example 1, 0 A solid catalyst containing 0.2 mmol / g zirconium and 0.8 mmol / g aluminum was prepared.

Polymerization of Propylene Polymerization of propylene was carried out in the same manner as in Example 1 except that the solid catalyst containing the above zirconium derivative was used as the catalyst. The results are shown in Table 4.

Examples 15 and 16 Preparation of a catalyst and polymerization of propylene were carried out in the same manner as in Example 14 except that the addition amount and the order of addition of methylaluminoxane were changed. The results are shown in Table 4.

Example 17 Preparation of Catalyst By adding an organozirconium compound ZrBz _2.2 Cl _1.8 (in the formula, Bz represents a benzyl group) having the following composition instead of tetrabenzylzirconium in the preparation of the catalyst of Example 1, 0 A solid catalyst containing 0.2 mmol / g zirconium and 0.8 mmol / g aluminum was prepared.

Polymerization of Propylene Polymerization of propylene was carried out in the same manner as in Example 1 except that the solid catalyst containing the above zirconium derivative was used as the catalyst. The results are shown in Table 4.

Example 18.19 A catalyst was prepared and propylene was polymerized in the same manner as in Example 17 except that the addition amount and the addition order of methylaluminoxane were changed. The results are shown in Table 4.

[Brief description of drawings]

FIG. 1 is a preparation diagram (flow chart diagram) of the catalyst of the present invention.

Claims (1)

[Claims] 1. A fine particle, porous alumina substantially free of adsorbed water and having a reactive surface hydroxyl group, is added to the general formula R ¹ _p MX.
_4-p (M is a transition metal of Group IVA of the periodic table, R ¹ is a hydrocarbon group or a substituted hydrocarbon group, X is a halogen, and _p is an integer of 2 to 4), and General formula AIR ² ₃ ( ² is an alkyl group having 1 to 10 carbon atoms)
An olefin polymer characterized by polymerizing or copolymerizing an olefin in the presence of a solid product obtained by catalytically reacting a water-modified organic aluminum compound obtained by modifying a trialkylaluminum compound represented by Manufacturing method.