JPH059445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a high-performance catalyst component that exhibits high activity when subjected to the polymerization of olefins and is capable of obtaining a stereoregular polymer in high yield. Specifically, a reaction product obtained by simultaneously contacting dialkoxymagnesium, an aromatic monocarboxylic acid ester, and a titanium halide is washed at least 10 times with an inert organic solvent in an amount equal to or more than that of the titanium halide. The present invention relates to a method for producing a catalyst component for polymerizing olefins, which comprises further contacting the catalyst component with a titanium halide. Conventionally, solid titanium halides have been well known and widely used as catalyst components for the polymerization of olefins. Because of the low polymerization activity (per unit polymerization activity), a so-called deashing step to remove catalyst residues was unavoidable. This deashing process uses a large amount of alcohol or chelating agent, so recovery or regeneration equipment is essential, and resources and
There are many energy and other related problems, and it is an important issue that those skilled in the art would like to solve as soon as possible. In order to eliminate this complicated deashing process, many studies have been made and proposals have been made to increase the polymerization activity per titanium in the catalyst component, especially in the catalyst component. In particular, a recent trend is to support transition metal compounds such as titanium halides, which are active ingredients, on carrier materials such as magnesium chloride, and when used in the polymerization of olefins, the polymerization activity per titanium in the catalyst component can be dramatically increased. I've seen many suggestions for increasing it. For example, in JP-A-50-126590, magnesium chloride as a carrier material is brought into contact with an aromatic monocarboxylic acid ester by mechanical means,
A method for obtaining a catalyst component by contacting the obtained solid composition with titanium tetrahalide in a liquid phase is disclosed. However, the chlorine contained in magnesium chloride, which is the main carrier material, has the disadvantage of having an adverse effect on the produced polymer, and therefore requires high activity to the extent that the influence of chlorine can be virtually ignored. However, there were still unresolved issues, such as the need to lower the concentration of magnesium chloride itself. Attempts have therefore been made to use substances other than magnesium chloride that can effectively act as carrier materials. However, the methods proposed so far can not only increase the polymerization activity per catalyst component but also fully satisfy the requirements in the technical field of maintaining a high yield of stereoregular polymers. has not been proposed. In order to solve the problems remaining in the prior art, the present inventors have devised a method to reduce the residual chlorine in the produced polymer while maintaining a high degree of polymerization activity per catalyst component and the yield of stereoregular polymer. As a result of intensive research, we have arrived at the present invention for this purpose, and we hereby propose it to you. That is, the present invention is characterized by (a) dialkoxymagnesium, (b) aromatic monocarboxylic acid ester, and (c) titanium represented by the general formula TiX ₄ (wherein X is a halogen element). The reaction product obtained by simultaneously contacting the halides is washed at least 10 times with an inert organic solvent in an amount equal to or more than that of the titanium halide, and then further (c) with the general formula TiX ₄ (in the formula X is a halogen element. When olefins are polymerized using the catalyst component obtained by the present invention, the activity is extremely high, so the amount of catalyst residue in the produced polymer can be kept extremely low, and the amount of residual chlorine can be kept very low. Since the amount of chlorine is small, the influence of chlorine on the produced polymer can be reduced. Chlorine contained in the produced polymer not only causes corrosion of equipment used in processes such as granulation and molding, but also causes deterioration and yellowing of the produced polymer itself, and this has been reduced. has extremely important meaning for those skilled in the art. In addition, in the industrial production of olefin polymers, it is common to allow hydrogen to coexist during polymerization from the viewpoint of MI control, but the catalyst component using magnesium chloride as a carrier does not become active in the coexistence of hydrogen. It also had the disadvantage that the stereoregularity was significantly reduced. However, when olefins are polymerized using the catalyst component obtained according to the present invention, the activity and stereoregularity hardly decrease even if hydrogen is present during the polymerization, and such effects are suppressed. This is of great benefit to those skilled in the art. Examples of the dialkoxymagnesium used in the present invention include diethoxymagnesium, dibutoxymagnesium, diphenoxymagnesium, dipropoxymagnesium, di-sec-butoxymagnesium, di-tert-butoxymagnesium, diisopropoxymagnesium, etc. Among them, diethoxymagnesium and dipropoxymagnesium are preferred. As the aromatic monocarboxylic acid ester used in the present invention, ethyl benzoate, ethyl P-anisate and ethyl P-toluate are preferred. The general formula TiX ₄ used in the present invention (in the formula
is a halogen element. Examples of the titanium halide represented by ) include TiCl ₄ , TiBr ₄ , TiI ₄ and the like, with TiCl ₄ being particularly preferred. The ratio of each component used is arbitrary as long as it does not adversely affect the performance of the catalyst component produced, and is not particularly limited, but usually the aromatic monocarboxylic acid ester is 0.01 g for 1 g of dialkoxymagnesium. ~10g, preferably 0.1-1g,
Titanium halide is 0.1g or more, preferably 5g
It is used in the above range. In the present invention, the dialkoxymagnesium, the electron donating substance, and the titanium halide are usually brought into contact at a temperature ranging from room temperature to the boiling point of the titanium halide used. The contact time is arbitrary as long as the above-mentioned substances can react sufficiently, but the contact time is usually in the range of 10 minutes to 100 hours. In the present invention, dialkoxymagnesium, aromatic monocarboxylic acid ester, and titanium halide need to be brought into contact at the same time, and in this case, it is preferable that a halogenated hydrocarbon or an aromatic hydrocarbon be present. The reaction product obtained by the contact is washed at least 10 times with an inert organic solvent such as n-heptane in an amount equal to or more than the titanium halide to remove unreacted components, and then further washed with the titanium halide. The catalyst component for polymerizing olefins, which is the object of the present invention, can be obtained by contacting with the compound.
The catalyst component is thoroughly washed with an inert organic solvent and then dried, or used as it is for the polymerization of olefins. These series of operations in the present invention are preferably carried out in the absence of oxygen, moisture, and the like. The catalyst component produced as described above is combined with an organoaluminum compound to form a catalyst for polymerizing olefins. The organoaluminum compound used is used in a molar ratio of 1 to 1000, preferably 1 to 300, per mole of titanium atoms in the catalyst component. Further, during the polymerization, it is possible to add and use a third component such as an electron-donating substance. Polymerization can be carried out in the presence or absence of an organic solvent, and the olefin monomer can be used in either gas or liquid state. The polymerization temperature is 200℃ or less, preferably 100℃ or less, and the polymerization pressure is 100Kg/cm ² ·G or less, preferably 50Kg/cm2.G or less.
^cm2・G or less. Olefins homopolymerized or copolymerized using the catalyst component produced by the method of the present invention include ethylene, propylene, 1-butene, 4-methyl-1
-Pentene etc. The present invention will be specifically explained below using Examples and Comparative Examples. Example 1 [Preparation of catalyst components] 5 g of diethoxymagnesium, 2.5 ml of ethyl benzoate, and methylene chloride were placed in a 500 ml round bottom flask that was sufficiently purged with nitrogen gas and equipped with a stirrer.
50 ml and 200 ml of TiCl ₄ were charged, the temperature was raised to 90°C, and the reaction was carried out with stirring for 2 hours. 40 minutes after the reaction
Wash 10 times with 200 ml of n-heptane at
200 ml of TiCl ₄ was added and reacted at 90°C for 2 hours with stirring. After the reaction was completed, the mixture was cooled to 40° C., and washed with 200 ml of n-heptane repeatedly. When chlorine was no longer detected in the washing solution, the washing was completed and the catalyst component was used. At this time, when the solid and liquid in the catalyst component was separated and the titanium content in the solid was measured, it was found to be 3.95% by weight. [Polymerization] Add 700 ml of n-heptane to an autoclave with an internal volume of 2.0 and a stirring device that was completely purged with nitrogen gas.
301 mg of triethylaluminum and 137 mg of ethyl p-toluate were charged while maintaining a nitrogen gas atmosphere.
mg, then 0.5 titanium atoms of the catalyst component.
mg was charged. After that, 300ml of hydrogen gas was charged and the temperature was raised to 60℃.
6Kg/ while increasing the temperature and introducing propylene gas.
Polymerization was carried out for 2 hours while maintaining a pressure of cm ² ·G. After completion of polymerization, separate the solid polymer obtained and add 80
It was heated to ℃ and dried under reduced pressure. On the other hand, the amount of polymer dissolved in the polymerization solvent after concentrating the liquid is defined as (A), and the amount of solid polymer is defined as (B). Further, the obtained solid polymer was extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane, and this amount was designated as (C). The polymerization activity (D) per catalyst component is expressed by the formula (D)=[(A)+(B)](g)/Amount of catalyst component (g). Furthermore, the yield (E) of crystalline polymer is expressed by the formula (E)=(C)/(B)×100(%), and the yield (F) of total crystalline polymer is expressed by the formula (F)=( Calculated from C)/(A)+(B)×100(%). In addition, residual chlorine in the produced polymer (G),
The MI of the produced polymer is represented by (H). The results obtained are
As shown in Table 1. Example 2 An experiment was conducted in the same manner as in Example 1 except that toluene was used instead of methylene chloride. In addition,
The titanium content in the solid content at this time was 3.52% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 3 An experiment was conducted in the same manner as in Example 1 except that methylene chloride was not used. Note that the titanium content in the solid content at this time was 3.80% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Comparative Example 1 [Preparation of catalyst component] 100 g of MgCl ₂ and 31.5 g of ethyl benzoate are pulverized for 18 hours under a nitrogen gas atmosphere. Thereafter, 100 g of the pulverized composition was taken out and the internal volume was
The mixture was placed in a 2000 ml glass container, 500 ml of TiCl ₄ was added thereto, and the reaction was stirred at 65° C. for 2 hours. After the reaction was completed, the mixture was cooled to 40°C, left to stand, and the supernatant liquid was removed by decantation. Next, n-butane 1000
ml was repeatedly washed, and when chlorine was no longer detected in the washing solution, the washing was completed and the catalyst component was used. At this time, when the solid and liquid in the catalyst component was separated and the titanium content in the solid was measured, it was 1.28% by weight.
It was hot. The polymerization was carried out in the same manner as in Example 1, except that 1.0 mg of the catalyst component was used as a titanium atom. The results obtained are shown in Table 1. 【table】

[Brief explanation of the drawing]

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

Claims (1)

[Claims] 1 (a) dialkoxymagnesium, (b) aromatic monocarboxylic acid ester and (c) general formula TiX ₄ (in the formula
is a halogen element. ) The reaction product obtained by simultaneously contacting the titanium halide represented by is washed at least 10 times with an inert organic solvent in an amount equal to or more than that of the titanium halide, and then (c) general 1. A method for producing a catalyst component for polymerizing olefins, which comprises bringing it into contact with a titanium halide represented by the formula TiX ₄ (wherein X is a halogen element).