JPH0680086B2 - 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 an olefin polymerization catalyst component obtained by contacting alkoxy magnesium, an aromatic dicarboxylic acid diester, a halogenated hydrocarbon and a titanium halide, and an olefin polymerization catalyst composed of 0-anisaldehyde and an organic aluminum compound. .

Conventionally, as a catalyst for olefin polymerization, a combination of a solid titanium halide and an organoaluminum compound as a catalyst component is well known and widely used, but the catalyst component and the weight of titanium per titanium in the catalyst component are widely used. The so-called deashing step for removing the catalyst residue was unavoidable because the yield of the coalescence (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) was low. 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 proposals to raise the price.

However, the chlorine contained in magnesium chloride, which forms the mainstream as a carrier substance, has a drawback that it has an adverse effect on the produced polymer as well as the halogen element in titanium halides. 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. 57-20
In 0454, a method for producing a catalyst component for polymerizing olefins was proposed, and the intended purpose was achieved. Further, when the polymerization of olefins, particularly stereoregular polymerization of propylene, 1-butene, etc. is industrially carried out, 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 in a catalyst that uses a catalyst component having a carrier of (1) 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 by using magnesium dihalide as a starting material, and an organoaluminum compound, an organic carboxylic acid ester, and M-O-R are prepared.
A method of using it for the polymerization of olefins in combination with a compound having a group has been shown, but 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 the same publication. As can be seen from the above example, very complicated operations are required, and it cannot be said that a practically sufficient one 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) titanium halide are brought into contact with each other. The present invention is to provide a catalyst for olefin polymerization comprising (B) 0-anisaldehyde and (C) 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 during polymerization is generally considered from the viewpoint of MI control and the like, but a catalyst using a catalyst component having the above magnesium chloride as a carrier coexists with hydrogen. Below, it had the disadvantage 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 stereoregularity are hardly reduced 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.

As the halogenated hydrocarbon used in the present invention, chlorides of aromatic or aliphatic hydrocarbons which are liquid at room temperature are preferable, for example, propyl chloride, butyl chloride, butyl bromide, propyl iodide, chlorobenzene, benzyl chloride, dichloroethane, Examples thereof include trichloroethylene, dichloropropane, dichlorobenzene, trichloroethane, carbon tetrachloride, chloroform and methylene chloride, with propyl chloride, dichloroethane, chloroform, carbon tetrachloride and methylene chloride being preferred.

Examples of the titanium halide represented by the general formula TiX ₄ (wherein X is a halogen element) used in the present invention include TiCl ₄ , TiBr ₄ , TiI _{4 and the} like, among which TiCl ₄ is preferable.

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, 1 g of dialkoxymagnesium, the diester of aromatic dicarboxylic acid is in the range of 0.01 to 2 g, the titanium halide is 0.1 g or more, preferably 1 g
It is the above range. Further, the halogenated hydrocarbon is used in an arbitrary ratio, but is preferably an amount capable of forming a suspension.

At this time, the contact order and contact method of each raw material forming the catalyst component are not particularly limited, but as a preferred embodiment, the suspension obtained by suspending the component (a) in the component (c) is obtained. A method in which the suspension is added to the component (d) to cause a catalytic reaction and the component (b) is allowed to coexist at any point in time can be mentioned.

As a contact condition of each raw material in the present invention, when a dialkoxy magnesium is suspended in a halogenated hydrocarbon, 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, in the temperature range from -10 ° C to the boiling point of the titanium halide used, for 10 minutes. It is preferably carried out for about 100 hours.

The composition obtained after the contact may be repeatedly contacted with a titanium halide, or may be washed with an organic solvent 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 0-anisaldecht and the organoaluminum compound to form a catalyst for olefin polymerization. The organoaluminum compound used is used in a molar ratio of 1 to 1000 per mole of titanium atom in the catalyst component, and the 0-anisaldecht is 1 or less, preferably 0.005 to 0.005 per mole of the organoaluminum compound. 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 100kg / 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-bottomed flask was charged with 5 g of diethoxymagnesium, 2.0 g of dibutyl phthalate and 25 ml of ethene chloride to give a suspension, and the mixture was stirred under reflux for 1 hour. This suspension was then 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 with stirring. After completion of the reaction, n-heptane 20 at 40 ℃
Wash 10 times with 0 ml, add 200 ml of TiCl ₄ and add 2 at 120 ° C.
The reaction was carried out with stirring for a time.

After the reaction was completed, it was cooled to 40 ° C, and then 200 ml of n-heptane
The washing 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 content of the catalyst component was separated and the titanium content of the solid content was measured to be 2.21% by weight.

〔polymerization〕

700 ml of n-heptane was charged into an autoclave with an internal volume of 2.0, which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
82 mg of o-anisaldehyde and then 0.2 mg of the above catalyst component were charged with titanium atoms. After that, 300 ml of hydrogen gas was charged, the temperature was raised to 70 ° C, and 6 kg / cm ² was introduced while introducing propylene gas.
-The pressure of G was maintained and superposition | polymerization was performed for 4 hours. After the completion of the polymerization, the solid polymer obtained was separated, heated to 80 ° C. and dried under reduced pressure to obtain 203 g of a solid polymer. On the other hand, the liquid was condensed to obtain 6.9 g of a polymer. The MI of the solid polymer
Was 13 and the bulk specific gravity was 0.38.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 6 hours, and 298 g of a solid polymer was obtained. The MI of the solid polymer was 11, and the bulk specific gravity was 0.40. Further, the liquid was condensed to obtain 9.9 g of a polymer.

Example 3 The same experiment as in Example 1 was conducted except that 131 mg of o-anisaldehyde was used. As a result, 197 g of a solid polymer was obtained. The MI of the solid polymer was 13, and the bulk specific gravity was 0.38. Further, the liquid was condensed to obtain 6.2 g of a polymer.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the present invention.

Claims (1)

[Claims] 1. (A) (a) dialkoxy magnesium,
(B) a diester of an aromatic dicarboxylic acid, (c) a halogenated hydrocarbon and a catalyst component obtained by contacting with a titanium halide represented by the general formula TiX ₄ (where X is a halogen element), (B ) A catalyst for olefin polymerization, which comprises 0-anisaldehyde and (C) an organoaluminum compound.