JPH0610209B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-performance catalyst which is highly active when subjected to polymerization of olefins and which is capable of obtaining a stereoregular polymer in high yield. The present invention relates to a catalyst component for olefin polymerization obtained by contacting alkoxymagnesium, diester of aromatic dicarboxylic acid, halogenated hydrocarbon and titanium halide, a catalyst for olefin polymerization comprising a nitrogen-containing organic compound and an organic aluminum compound. .

Conventionally, as a catalyst for polymerization of olefins, a combination of a solid titanium halide as a catalyst component and an organoaluminum compound is well known and widely used. Since the yield of the polymer (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) is low, a so-called deashing step for removing the catalyst residue was unavoidable. Since this deashing process uses a large amount of alcohol or a chelating agent, a recovery device or a regenerating device for them is indispensable, and resources,
There were many energy and other incidental problems, and it was an important issue for those skilled in the art to solve immediately. In order to eliminate this complicated deashing step, many studies have been made and proposed to increase the polymerization activity per catalyst component, especially titanium per catalyst component.

In particular, as a recent tendency, a transition metal compound such as titanium halide, which is an active component, is supported on a carrier substance such as magnesium chloride, and when it is subjected to the polymerization of olefins, the polymerization activity per titanium in the catalyst component is dramatically increased. There are many suggestions to raise it.

However, the chlorine contained in magnesium chloride, which forms the mainstream as a carrier substance, has the drawback that it adversely affects the polymer produced as well as the halogen element in titanium halides, and therefore the effect of chlorine is virtually ignored. There was an unsolved part such as a high activity required, or the need to keep the concentration of magnesium chloride itself low.

The inventors of the present invention have disclosed that, in order to reduce the residual chlorine in the produced polymer while maintaining the polymerization activity per catalyst component and the yield of the stereoregular polymer at a high level, Japanese Patent Application No. 57-200
In 454, a method for producing a catalyst component for olefin polymerization was proposed, and the intended purpose was achieved. Further, when industrially polymerizing olefins, particularly stereoregular polymerization of propylene, 1-butene, etc., it is usually necessary to make an electron donating compound such as an aromatic carboxylic acid ester coexist in the polymerization system. It is indispensable for a catalyst that uses a catalyst component as a carrier in combination with an organoaluminum compound. However, this aromatic carboxylic acid ester imparts an ester odor peculiar to the produced polymer, and its removal has become a major problem in the art.

Further, in a so-called highly active supported catalyst, such as a catalyst using a catalyst component having magnesium chloride as a carrier,
Although the activity at the initial stage of polymerization is high, deactivation is large, which causes a problem in the process operation, and when it is necessary to prolong the polymerization time such as block copolymerization, it is practically impossible to use. In order to improve this point, for example, in JP-A-54-94590, a catalyst component is prepared using magnesium dihalide as a starting material, and an organoaluminum compound, an organic carboxylic acid ester, and a compound having an M-O-R group. Although a method used for the polymerization of olefins in combination with the above is shown, since the organic carboxylic acid ester is used during the polymerization, the problem of the odor of the produced polymer has not been solved, and from the examples of the publication. As can be seen from the above, very complicated operations are required, and it cannot be said that a practically sufficient product is obtained in terms of performance and sustainability of activity.

The inventors of the present invention have reached the present invention as a result of earnest research in order to solve the problems remaining in such conventional techniques, and make a proactive proposal.

That is, the feature of the present invention is that (A) (a) dialkoxymagnesium, (b) diester of aromatic dicarboxylic acid, (c) halogenated hydrocarbon, and (d) general formula TiX ₄ (wherein X is a halogen element.) A catalyst component obtained by contacting a titanium halide represented by the formula (hereinafter sometimes simply referred to as titanium halide) with the titanium halide. Another object of the present invention is to provide a catalyst for olefin polymerization, which comprises (B) a nitrogen-containing organic compound and (C) an organoaluminum compound.

When olefins are polymerized using the catalyst obtained according to the present invention, the resulting polymer has extremely high stereoregularity, and the catalyst has a very high activity. Can be controlled to an extremely low level, and the effect of chlorine on the produced polymer can be reduced to such an extent that a deashing step is not required at all due to the small amount of residual chlorine.

Chlorine contained in the produced polymer causes corrosion of equipment used in processes such as granulation and molding, and also causes deterioration of the produced polymer itself, yellowing, etc. Has a very important meaning to those skilled in the art.

Further, the feature of the present invention is that not only the big problem of the odor of the produced polymer is solved by not using the aromatic carboxylic acid ester at the time of polymerization, but also the activity of the catalyst per unit time is increased with the progress of the polymerization. It is an object of the present invention to provide a catalyst that solves the essential drawback of so-called highly active supported catalysts, which is greatly reduced.

Further, in industrial production of olefin polymers, coexistence of hydrogen at the time of polymerization is generally considered from the viewpoint of MI control and the like, but a catalyst using the above-mentioned catalyst component having magnesium chloride as a carrier is hydrogen. In the coexistence, it had a drawback that activity and stereoregularity were significantly reduced.
However, when the olefins are polymerized in the coexistence of hydrogen using the catalyst obtained by the present invention, the activity and the stereoregulatory property are hardly lowered even when the MI of the produced polymer is extremely high. Such an effect brings extremely great benefits to those skilled in the art.

In addition to the effects of the present invention, in the industrial production of olefin polymers, the bulk specific gravity of the produced polymer is also a very large problem, but the catalyst obtained by the present invention also has extremely excellent characteristics in this respect. Is shown.

As dialkoxy magnesium used in the present invention, diethoxy magnesium, dibutoxy magnesium, diphenoxy magnesium, dipropoxy magnesium, di-sec-butoxy magnesium, di-tert-
Examples thereof include butoxy magnesium and diisopropoxy magnesium, and among them, diethoxy magnesium and dipropoxy magnesium are preferable.

The diester of aromatic dicarboxylic acid used in the present invention is preferably a diester of phthalic acid or terephthalic acid, for example, dimethyl phthalate, dimethyl terephthalate, diethyl phthalate, diethyl terephthalate, dipropyl phthalate, dipropyl terephthalate, dibutyl phthalate, dibutyl. Examples thereof include terephthalate, diisobutylphthalate, diamylphthalate, diisoamylphthalate, ethylbutylphthalate, ethylisobutylphthalate and ethylpropylphthalate.

The halogenated hydrocarbon used in the present invention is preferably a chloride of an aromatic or aliphatic hydrocarbon which is liquid at room temperature, for example, propyl chloride, butyl bromide, butyl bromide, propyl iodide, chlorobenzene, benzyl chloride, dichloroethane. , Trichloroethylene, dichloropropane, dichlorobenzene, trichloroethane, carbon tetrachloride, chloroform, methylene chloride and the like, among which propyl chloride, dichloroethane, chloroform, carbon tetrachloride and methylene chloride are preferred.

Formula TiX ₄ used in the present invention (wherein X is a halogen element.) TiCl ₄ as a titanium halide represented by, TiBr _4, TiI ₄ but like among them TiCl ₄
Is preferred.

The nitrogen-containing organic compound used in the present invention preferably has an alkoxy group having 1 to 10 carbon atoms.

Examples of the organoaluminum compound used in the present invention include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof. Among them, trialkylaluminums are preferable, and triethylaluminums and triisobutylaluminums are particularly preferable.

When obtaining the catalyst component of the present invention, the use ratio of each raw material constituting the catalyst component is optional, and is not particularly limited, as long as it does not adversely affect the performance of the produced catalyst component. Usually, the diester of aromatic dicarboxylic acid is in the range of 0.01 to 2 g, and the titanium halide is in the range of 0.1 g or more, preferably 1 g or more, based on 1 g of dialkoxymagnesium. Further, the halogenated hydrocarbon is used in an arbitrary ratio, but is preferably an amount capable of forming a suspension.

At this time, the order of contact of the respective raw materials forming the catalyst component and the catalyst method are not particularly limited, but in a preferred embodiment, the component (a) is suspended in (c) and the obtained suspension is obtained. Liquid as component (d)
To react with each other at any point of time
A method of making (c) coexist can be mentioned.

In the present invention, as a contact condition of each raw material, when suspended in a halogenated hydrocarbon of dialkoxymagnesium, the boiling point of the halogenated hydrocarbon usually used from 0 ° C. in the presence or absence of a diester of an aromatic dicarboxylic acid. It is preferable to maintain the suspension at a temperature of up to 100 hours or less, preferably 10 hours or less.

The contact between the suspension and the titanium halide in the present invention is carried out in the presence or absence of a diester of an aromatic dicarboxylic acid, usually in the temperature range from -10 ° C to the boiling point of the titanium halide used, for 10 minutes to 100 hours is preferable.

The catalyst component used in the present invention can be obtained by further bringing a titanium halide into contact with the composition produced by the contact, and the catalyst conditions at this time may be the same as those described above. It is also possible to wash the catalyst component and / or with an inert organic catalyst such as n-heptane.

It is preferable that these series of operations in the present invention are performed in the absence of oxygen and water.

The catalyst component produced as described above is combined with the nitrogen-containing organic compound and the organoaluminum compound to form an olefin polymerization catalyst. The organoaluminum compound used is used in a range of 1 to 1000 in molar ratio per mole of titanium atom in the catalyst component, and the nitrogen-containing compound is 1 or less in molar ratio per mole of organoaluminum compound, preferably 0.005 to Used in the range of 1.0.

The polymerization can be carried out in the presence or absence of an organic solvent, and the olefin monomer can be used in either a gas or liquid state. Polymerization temperature is 200
℃ or less preferably 100 ℃ or less, the polymerization pressure is 100 Kg / c
m ₂ · G or less, preferably 50 Kg / cm ₂ · G or less.

The olefins homopolymerized or copolymerized using the catalyst produced by the method of the present invention are ethylene, propylene,
1-butene, etc.

The present invention will be specifically described below with reference to examples.

Example 1 [Preparation of catalyst component] Nitrogen gas was sufficiently replaced, and a capacity of 200 m equipped with a stirrer
A 1-liter round bottom flask was charged with 5 g of diethoxymagnesium, 2.0 g of dibutyl phthalate and 25 ml of methylene chloride to give a suspension, and the mixture was stirred under reflux for 1 hour. Then, this suspension was pressure fed into 200 ml of room temperature TiCl ₄ in a 500 ml round bottom flask equipped with a stirrer, heated to 120 ° C. and reacted for 2 hours while stirring. N-heptane at 40 ℃ after the reaction
It was washed 10 times with 200 ml, 200 ml of TiCl ₄ was newly added, and the mixture was reacted at 120 ° C. for 2 hours with stirring.

After the reaction was completed, it was cooled to 40 ° C., and then n-heptane 200 m
The washing with l was repeated, and when chlorine was not detected in the washing liquid, the washing was completed and the catalyst component was used.
At this time, the solid-liquid in the catalyst component was separated and the titanium content of the solid was measured to be 2.21% by weight.

〔polymerization〕

700 ml of n-heptane was charged into an autoclave with a stirrer having an internal volume of 2.0 l, which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
170 mg of o-anilide and then 0.2 mg of the above catalyst component as titanium atoms were charged. Then add 300 ml of hydrogen gas.
6Kg / cm ₂ · G while raising the temperature to 70 ℃ and introducing propylene gas
Polymerization was carried out for 4 hours while maintaining the pressure. After the completion of the polymerization, the solid polymer obtained was separated, heated to 80 ° C. and dried under reduced pressure to obtain 216 g of a solid polymer. Meanwhile, the liquid was condensed to obtain 7.1 g of a polymer. Further, the MI of the solid polymer
Was 18 and the bulk specific gravity was 0.37.

Example 2 When an experiment was conducted in the same manner as in Example 1 except that the polymerization time was 6 hours, 305 g of a solid polymer was obtained. The MI of the solid polymer was 17, and the bulk specific gravity was 0.40. Further, the liquid was condensed to obtain 10.2 g of a polymer.

Example 3 The same experiment as in Example 1 was conducted except that 126 mg of o-aniline was used. As a result, 238 g of a solid polymer was obtained. The MI of the fixed polymer was 13, and the bulk specific gravity was 0.38.
Further, the liquid was contracted to obtain 10.3 g of a polymer.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the catalyst preparation process of the present invention.

Claims (1)

[Claims] 1. (A) (a) dialkoxy magnesium,
A composition produced by contacting (b) a diester of an aromatic dicarboxylic acid, (c) a halogenated hydrocarbon, and (d) a titanium halide represented by the general formula TiX ₄ (where X is a halogen element). To a catalyst component obtained by contacting the titanium halide with (1) A catalyst for olefin polymerization, comprising a nitrogen-containing organic compound represented by the formula (wherein R is an alkoxy group) (hereinafter sometimes simply referred to as a nitrogen-containing organic compound) and (C) an organoaluminum compound. .