JPH0441682B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for polymerizing olefins, particularly ethylene or ethylene and other 1-olefins. Specifically, highly active olefin polymerization characterized by using a solid catalyst component obtained by reacting a hydrocarbon-soluble component obtained from a specific magnesium di-alkoxide and a transition metal alkoxide with a specific halogenated organoaluminium compound. Regarding the method.

(Prior Art) In the polymerization of olefins, particularly ethylene or ethylene and other 1-olefins, a catalyst system consisting of a solid catalyst component containing magnesium, halogen, and titanium and an organoaluminum compound has traditionally been used with high activity. is known to show. There are many proposals for synthesizing this magnesium-containing solid catalyst component, such as synthesis from inorganic magnesium chloride and organic magnesium. Publication, U.S. Patent No.
In specification No. 4526943, specification No. 4544647, etc.,
Certain organomagnesium solutions and alcohol
A method has been published in which a homogeneous solution is prepared from an OH group-containing organic compound and a transition metal alkoxide, and this is halogenated with organoaluminum halide to synthesize a solid catalyst component.

For example, the catalyst obtained by the technique described in JP-A No. 61-250004 has extremely high activity and does not require removal of the catalyst from the polymer, and the obtained polymer has a relatively wide molecular weight. It is possible to produce a polymer having a wide molecular weight distribution suitable for extrusion molding or blow molding, for example, by combining it with a multi-stage polymerization method.

However, the technique described in JP-A No. 61-250004 has the problem that, for example, in catalyst production, a large amount of organoaluminum compound is required to form a homogeneous solution when synthesizing a specific hydrocarbon-soluble magnesium-containing component. It was hot.

On the other hand, in the specification of Japanese Patent Application Publication No. Sho 61-500438 filed by Lithium Corporation of America, it is disclosed that a specific magnesium di-alkoxide is a precursor of a magnesium chloride support used in the production of Ziegler catalysts. It has been disclosed that it can be used as For example, it has been disclosed that magnesium-2-ethoxyethoxide can be chlorinated in a hydrocarbon solvent and used as a support for a catalyst for α-olefin polymerization.

(Problems to be Solved by the Invention) According to the disclosure of the above-mentioned Japanese Patent Application Publication No. 61-500438,
Since an organoaluminum compound is not substantially used during the synthesis of the hydrocarbon-soluble magnesium-containing component, a large amount of an organoaluminum compound may not be necessary as a result. This suggests that the problem may be solved.

However, in the above-mentioned Japanese Patent Application Publication No. 61-500438, the gist of the invention is
The content of the specification mainly relates to the method for synthesizing the alkoxide itself, and there is no specific technical disclosure regarding the synthesis of the catalyst solid. Furthermore, although no specific disclosure has been made, in the case of magnesium-2-ethoxyethoxide, which has been suggested to have the potential for catalytic solid synthesis, particle properties are There was a problem in that it was difficult to synthesize a good solid catalyst.

(Means for Solving the Problems) As a result of repeated research in order to solve the above problems, the present inventors have discovered that when synthesizing a homogeneous solution of a specific titanium-containing hydrocarbon-soluble magnesium component, The present invention was achieved by discovering that a highly active catalyst with good particle properties could be synthesized by using magnesium dilkoxide.

That is, the present invention provides a hydrocarbon obtained by mixing (A)()(a) a hydrocarbon-soluble dialkoxymagnesium compound having an alkyl group at the 2-position and (b) a titanium alkoxide in a hydrocarbon. solution and () general formula AlR _3-o X _o (wherein R is a hydrocarbon group, X is a halogen, and n is 1≦
Polymerization of olefin characterized by using a catalyst consisting of a solid catalyst component (A) obtained by reacting a halogenated organoaluminum compound represented by n≦2 and (B) an organoaluminum compound. It is related to the method.

The present invention will be explained in detail below.

Examples of the hydrocarbon-soluble dialkoxymagnesium compound having an alkyl group at the 2-position used in the present invention (A)()(a) include magnesium-2-methyl-pentyl oxide, magnesium-2-ethyl-hexyl oxide, Magnesium
Examples include 2-ethyl-4-methyl-pentyl oxide, and magnesium-2-methyl-pentyl oxide is particularly preferred.

In addition, these compounds may contain a large number of magnesium di-alcosides, such as magnesium di-isopropoxide, magnesium di-isobutoxide, magnesium di-sec-butoxide, to the extent that their solubility in hydrocarbon media is not impaired. It can also be used as a mixture with etc. Note that a trace amount of alkoxides such as aluminum, sodium, potassium, calcium, barium, boron, and zinc may be added in order to increase the solubility in hydrocarbons or lower the viscosity of the solution. These hydrocarbon-soluble magnesium di-alkoxides may be synthesized according to, for example, Japanese Patent Publication No. 500438/1983, although there are no particular limitations on the production method. That is, for example, it may be synthesized from dialkylmagnesium and the corresponding alcohol.

Examples of the titanium alkoxide used in the present invention (A)()(a) include tetraisopropoxytitanium, tetra-n-butoxytitanium, and tetra(2-ethylhexoxy)titanium. Particularly preferred examples include tetraisopropoxytitanium and tetra-n-butoxytitanium.

The halogenated organoaluminum compound used in the present invention () has the general formula AlR _3-o X _o (wherein R is a hydrocarbon group, X is a halogen, and n is 1≦n≦2). Preferred examples include ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum chloride, and the like. Particularly preferably, ethylaluminum dichloride is used.

Next, the organic aluminum compound used in the present invention (B) will be explained.

As the organic aluminum compound used in the present invention (B), trialkylaluminum or dialkylalinium hydride is particularly preferably used. For example, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tridecylaluminum,
Mention may be made of diethylaluminium hydride, isoprenylaluminum and mixtures thereof.

Next, the synthesis of the solid catalyst component (A) will be explained.

First, a description will be given of (A)() mixing the hydrocarbon-soluble dialkoxymagnesium compound (a) and (b) the transition metal alkoxide to obtain a hydrocarbon solution.

The reaction is carried out in an atmosphere sufficiently excluded from moisture and oxygen in an inert hydrocarbon medium such as aliphatic hydrocarbons such as hexane, heptane, benzene,
The reaction can be carried out in an aromatic hydrocarbon such as toluene or xylene, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane, or a mixed medium thereof. In terms of catalytic performance, an aliphatic hydrocarbon medium is preferably used. The reaction temperature is not particularly limited, and can be carried out at a commonly used temperature, for example, between room temperature and 100°C. There is no particular restriction on the reaction ratio of each component, but preferably,
The ratio of the transition metal atom in the transition metal alkoxide (b) to one atom of magnesium in the hydrocarbon-soluble dialkoxymagnesium compound (a) is 0.02 to
0.2, particularly preferably 0.05 to 0.1 is recommended.

Next, a method for obtaining the solid catalyst component (A) by reacting the obtained hydrocarbon-soluble component () with the halogenated organic aluminum compound () will be explained.

The reaction is carried out in an atmosphere sufficiently excluded from moisture and oxygen in an inert hydrocarbon medium such as aliphatic hydrocarbons such as hexane, heptane, benzene,
The reaction can be carried out in an aromatic hydrocarbon such as toluene or xylene, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane, or a mixed medium thereof. From the viewpoint of catalytic performance, an aliphatic hydrocarbon medium is preferably used. The reaction temperature is not particularly limited and can be carried out at a commonly used temperature, for example between room temperature and 100°C, but is preferably carried out at a temperature of 20 to 60°C in view of the progress of the reaction. There is no particular restriction on the reaction ratio of the two components, but preferably the reaction ratio is based on the number of Mg atoms in the hydrocarbon-soluble component.
A ratio of Cl atoms of 6 to 20, particularly preferably 8 to 12, is recommended. Regarding the reaction method, there is a simultaneous addition method in which the two types of catalyst components are simultaneously introduced into the reaction zone and reacted, or a method in which the first type of catalyst component is charged into the reaction zone in advance, and then the remaining catalyst components are introduced into the reaction zone. Any of the so-called forward (reverse) addition methods, in which the reaction is carried out while reacting, is possible and gives preferable results.

Next, a method of combining the solid catalyst component (A) obtained by the above reaction with the organoaluminum compound (B) will be explained.

The solid catalyst component (A) and the organoaluminum compound (B) may be added to the polymerization system under polymerization conditions, or may be combined in advance prior to polymerization. It is also possible to use a method in which the solid catalyst component is treated in advance with the organoaluminum compound and then further combined with the organoaluminum compound and fed into the polymerization system. The recommended molar ratio of both components to be combined is (organic Al)/Ti in the range of 0.01 to 3000.

Next, a method for polymerizing olefin using the catalyst of the present invention will be explained.

Olefins that can be polymerized using the catalysts of the invention are alpha-olefins, especially ethylene. Furthermore, the catalyst of the present invention can also be used for copolymerization of ethylene with monoolefins such as propylene, putene-1, hexene-1, etc., or for polymerization in the coexistence of dienes such as butadiene, isoprene, etc.

By carrying out copolymerization using the catalyst of the present invention, it is possible to produce a polymer having a density in the range of 0.91 to 0.97 g/cm ³ .

As the polymerization method, usual suspension polymerization, solution polymerization, and gas phase polymerization are possible. In the case of suspension polymerization or solution polymerization, the catalyst is a polymerization solvent such as propane,
It is introduced into the reactor together with aliphatic hydrocarbons such as butane, pentane, hexane, heptane, aromatic hydrocarbons such as benzene, toluene, xylene, and alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylene is introduced into the reactor under an inert atmosphere. The polymerization can be carried out at a temperature of room temperature to 320°C by injecting 1 to 200 kg/cm ² of the polymer. It is also possible to apply a so-called high-pressure polymerization method in which polymerization is carried out using a tubular reactor, an autoclave reactor, an autoclave to a tubular reactor, etc. at a pressure of 200 to 2000 Kg/cm ² and a temperature of 150 to 300°C. be.

On the other hand, in gas phase polymerization, ethylene is heated at a pressure of 1 to 50 kg/cm ² at a temperature of room temperature to 120°C, using a fluidized bed, moving bed, etc. to ensure good contact between ethylene and the catalyst.
Alternatively, polymerization can be carried out by means of mixing by stirring or the like.

The polymerization may be carried out in a conventional one-stage polymerization using one reaction zone, or using multiple reaction zones.
It may also be carried out by so-called multi-stage polymerization. The catalyst of the present invention is highly active, and the step of removing catalyst residue from the produced polymer can naturally be omitted. Furthermore, the polymer polymerized using the catalyst of the present invention can be
Even stage polymerization has a relatively wide molecular weight distribution, and in particular, by applying multistage polymerization in which polymerization is performed under two or more different reaction conditions, it is possible to produce polymers with an even wider molecular weight distribution, making it suitable for blow molding and extrusion molding applications. It is extremely suitable for

In order to adjust the molecular weight of the polymer, it is of course possible to use known techniques such as adjusting the polymerization temperature, adding hydrogen to the polymerization system, or adding an organometallic compound that tends to cause chain transfer. Furthermore, it is also possible to perform polymerization by combining methods such as adding a titanate ester to control density and molecular weight.

(Examples) Examples of the present invention will be shown below, but the present invention is not limited to these Examples in any way.

In addition, the catalytic activity in the examples refers to the monomer pressure.
At 10 kg/cm ² , it represents the amount of polymer produced (g) per 1 g of catalyst solid component/1 hour. Also, MI
stands for melt index, ASTM D-
1238, measured at a temperature of 190°C and a load of 2.16 kg. FR has a temperature of 190℃ and a load of 21.6Kg.
It is the quotient obtained by dividing the value measured by MI by MI, and is known to those skilled in the art as an index representing the breadth of molecular weight distribution.

Example 1 1 Synthesis of solid catalyst component (A) 0.5150 mol of magnesium-di-2methylpentyl oxide/Isopar (8 carbon atoms
~10 paraffinic hydrocarbon mixed solvent) solution (manufactured by Lithium Corporation of America)
Weigh 48.5 ml (25 mmol) into a 200 ml flask with a dropping funnel that had been purged with dry nitrogen to remove moisture and oxygen, and add 2.5 ml of a 1 mol/hexane solution of tetra-ico-propoxytitanium.
(2.5 mmol) was added dropwise under stirring at room temperature.

The resulting solution was a homogeneous and clear hydrocarbon solution.

To this homogeneous solution, add 62.5 ml (125 ml) of 2 mol/hexane solution of ethylaluminum dichloride.
mmol) was added dropwise under stirring at approximately 25°C, and further heated to 50°C.
The mixture was aged for 2 hours to obtain a slurry containing a solid catalyst component.

The obtained slurry was repeatedly decanted using hexane to thoroughly wash and remove the Al component in the liquid phase, thereby obtaining a solid catalyst component (A). The amount of Ti in this solid catalyst was 3.9wt%.

2 Polymerization A slurry containing 2 mg of the solid catalyst component (A) synthesized in 1 and 0.20 mmol of triisobutylaluminum as the organometallic compound (B) were mixed with 0.8 of hexane obtained by dehydrating and deoxygenating the inside of the slurry, which was vacuum degassed and replaced with nitrogen. was placed in an autoclave.
Keep the internal temperature of the autoclave at 80℃ and add hydrogen to
Add Kg/cm ² and add ethylene to bring the total pressure to 10Kg/cm ²
And so. The total pressure is increased by replenishing ethylene.
Polymerization was carried out for 1 hour while maintaining the pressure at 10 kg/cm ² to obtain 70 g of polymer. Catalytic activity was 35000 g/g-solid catalyst/hr, MI was 0.72, and FR46.

Comparative Example The solid catalyst component of Example 1 was changed from magnesium-di-2-methylpentyl oxide to 0.93 mol of magnesium-2-ethoxyethoxide/cyclohexane solution (manufactured by Lithium Corporation of America), 26.9 ml (25 mmol). It was synthesized in the same manner as in Example 1.

After adding the titanium component, the titanium-containing hydrocarbon soluble magnesium component was a homogeneous solution.

However, when ethylaluminum dichloride is added to precipitate the solid catalyst component, most of the precipitate becomes a viscous slurry that adheres to the flask wall, and the particle properties are such that cleaning and recovery operations such as decantation and filtration are impossible. It was a bad one.

Example 2 The same procedure as in Example 1 was carried out except that during the synthesis of the solid catalyst in Example 1, magnesium-di-2-methylpentyl oxide was changed to 0.9 mol of magnesium-di-2-ethylhexyl oxide/27.8 ml (25 mmol) of a cyclohexane solution. Performed synthesis and polymerization.

Polymer yield is 75g, catalyst activity 37500g/g-
The solid catalyst hr and MI were 0.68 and FR44.

(Effect of the invention) When the method of the present invention is used to synthesize a specific titanium-containing hydrocarbon-soluble magnesium component in the production of a catalyst, there is no need to newly add an organoaluminum compound to obtain a homogeneous solution. A catalyst with good properties and high activity can be synthesized. That is, according to the conventional technique disclosed in JP-A No. 61-250004, for example, in order to obtain a homogeneous hydrocarbon solution of titanium-containing magnesium, 0.5 mole of organic An aluminum compound was needed. In contrast, the method of the present invention, e.g.
If 2-methyl pentoxide is used, a titanium-containing hydrocarbon-soluble magnesium homogeneous solution can be obtained without newly adding an organoaluminum compound to make a homogeneous solution as in the example. In the present invention, it is important to use a hydrocarbon-soluble dialkoxymagnesium compound having an alkyl group at the 2-position. In the case of magnesium di-alkoxide which does not have the following, for example, magnesium di-2-ethoxyethoxide, the properties of the catalyst particles are extremely poor and the catalyst synthesis itself is difficult.

[Brief explanation of drawings]

FIG. 1 is a schematic flowchart illustrating aspects of the present invention.

Claims (1)

[Claims] 1 (A)()(a) A carbonized compound obtained by mixing a hydrocarbon-soluble dialkoxymagnesium compound having an alkyl group at the 2-position and (b) a titanium alkoxide in a hydrocarbon. Hydrogen solution and () General formula AlR _3-o X _o (wherein R is a hydrocarbon group, X is a halogen, and n is 1
A solid catalyst component (A) obtained by reacting a halogenated organoaluminum compound represented by ≦n≦2) and (B) an organoaluminum compound. Polymerization method. 2. The method for polymerizing olefins according to claim 1, wherein the hydrocarbon-soluble dialkoxymagnesium compound having an alkyl group at the 2-position of (a) is magnesium-di-2-methylpentyl oxide.