JPH0442409B2 - - 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 used in the polymerization of olefins and can provide a stereoregular polymer in high yield. Magnesium is suspended in a liquid halogenated hydrocarbon and then contacted with a titanium halide, and the resulting composition is dried and then contacted again with the titanium halide, at some point adding carbon to the titanium halide. The present invention relates to a method for producing a catalyst component for polymerizing olefins, which comprises bringing it into contact with an acid ester. 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 problem that those skilled in the art would like to solve as soon as possible. In order to eliminate this complicated deashing step, 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 carboxylic acid ester by mechanical means, and titanium tetrahalide is added to the resulting solid composition in a liquid phase. A method of contacting catalyst components is disclosed. However, the chlorine contained in magnesium chloride, like the halogen element in titanium halide, not only causes deterioration and yellowing of the produced polymer, but also causes corrosion of equipment used in processes such as granulation and molding. Therefore, high activity is required to the extent that the influence of chlorine can be virtually ignored, but the catalyst components using magnesium chloride as a carrier material disclosed in the above publications have not been shown to have sufficient activity to date. Nothing showing good performance has been obtained. As a result of intensive research to solve the problems remaining in the conventional technology, the present inventors created a suspension by charging fatty acid magnesium, dialkoxymagnesium, and carboxylic acid ester into liquid halogenated hydrocarbon. A composition obtained by contacting the suspension with a titanium halide represented by the general formula TiX ₄ (wherein X is a halogen element) while stirring the suspension under reflux. things from 0.01
After drying under reduced pressure of 1.0 torr, it was brought into contact with the titanium halide again, and the catalyst performance was able to be dramatically improved. As a result, it was possible to reduce the amount of chlorine contained in the catalyst component and the amount of chlorine in the produced polymer to a completely negligible level. 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. To further comment on the effects of the present invention, the catalyst component obtained by the method of the present invention has the effect of reducing deterioration over time of the catalyst component, which has been a particular problem in conventional high-performance catalyst components. In addition, the particle size of the catalyst component produced by changing the degree, method, etc. of the drying step included in the manufacturing process of the catalyst component, and by extension the particle size of the polymer obtained by using the catalyst component. can also be controlled. This is a very great advantage as a catalyst component for industrial use. As the fatty acid magnesium used in the present invention, saturated fatty acid magnesium is preferred, and among these, magnesium stearate, magnesium octoate, magnesium decanoate, and magnesium laurate are preferred. Examples of the dialkoxymagnesium used in the present invention include diethoxymagnesium, dibutoxymagnesium, diphenoxymagnesium, dibropoxymagnesium, di-sec-butoxymagnesium, di-tert-butoxymagnesium, diisopropoxymagnesium, etc. can give. Examples of the carboxylic esters used in the present invention include aliphatic carboxylic esters such as ethyl acetate and methyl methacrylate, aromatic carboxylic esters such as ethyl toluate, ethyl anisate, and ethyl benzoate. However, among these, aromatic carboxylic acid esters are preferred. Liquid halogenated hydrocarbons used in the present invention include propyl chloride, butyl chloride, butyl bromide, propyl iodide, chlorobenzene, benzyl chloride, dichloroethane, trichloroethylene, dichloropropane, dichlorobenzene, trichloroethane,
Examples include carbon tetrachloride, chloroform, methylene chloride, etc. 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 preferred. The ratio of each component used in the present invention is arbitrary as long as it does not adversely affect the performance of the catalyst component produced, and is not particularly limited, but usually carboxylic acid ester is The class is 0.01~2
g, preferably in the range of 0.1 to 1 g, and titanium halide is used in the range of 0.1 g or more, preferably 1 g or more. Further, the liquid halogenated hydrocarbon can be used in any proportion as long as it can form a suspension. In the present invention, the components are brought into contact by charging a liquid of fatty acid magnesium, dialkoxymagnesium, and carboxylic acid ester to a halogenated hydrocarbon, usually at room temperature, to form a suspension.
While increasing the temperature and stirring the suspension under reflux,
The heating time is 100 hours or less, preferably 10 hours or less. At this time, it is necessary that the suspension does not become a uniform solution. Further, the contact between the suspension and the titanium halide is usually carried out at -20°C to the boiling point of the titanium halide used, preferably at 50°C.
It is carried out at a temperature of ~120°C for a period of 10 minutes to 10 hours. At this time, it is preferable to add the suspension to the titanium halide. In addition, the obtained composition was dried at 0.05 to 1.0 torr,
It is preferably carried out under reduced pressure of 0.1 to 0.5 torr.
Depending on the degree of vacuum drying, it is possible to control the particle size of the catalyst component produced, and thus also the particle size of the produced polymer. Contact with titanium halide after drying is usually -20
C. to the boiling point of the titanium halide used, preferably 50.degree. C. to 120.degree. C., for a period of 10 minutes to 10 hours. In the present invention, the contacting of each component is carried out while stirring using a container equipped with a stirrer. In the present invention, after contact with titanium halide,
It is also possible to wash with an organic solvent such as n-heptane. These series of operations of 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, it is not prohibited to add and use a third component such as an electron-donating substance during the polymerization. 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°C or less, preferably 100°C or less, and the polymerization pressure is 100Kg/cm ² ·G or less, preferably 50Kg/cm ² ·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] A round bottom flask with a capacity of 200 ml, which was sufficiently purged with nitrogen gas and equipped with a stirrer, was equipped with 5 g of magnesium stearate, 5 g of diethoxymagnesium, 3.0 ml of ethyl benzoate, and 50 ml of methylene chloride. The mixture was stirred under reflux for 1 hour to form a suspension. This suspension was then pumped into 200 ml of TiCl ₄ at 0° C. in a 500 ml round bottom flask equipped with a stirrer.
The temperature was raised to 90°C, and the reaction was carried out with stirring for 2 hours.
After the reaction was completed, the solid portion was separated by washing 10 times with 200 ml of n-heptane at 40°C, and the titanium content was measured to be 3.76% by weight. This solid part
After drying under reduced pressure to a degree of vacuum of 0.1 torr, 150 ml of TiCl ₄ was added and reacted at 90° C. for 2 hours with stirring. After the reaction was completed, it was washed 10 times with 200 ml of n-heptane at 40°C to obtain a catalyst component. In addition,
At this time, the solid and liquid in the catalyst component were separated and the titanium content in the solid was measured and found to be 3.26% 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). In addition, the yield (E) of crystalline polymer is expressed by the formula (E) = (C) / (B) × 100 (%), and the yield (F) of the 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 2.5 ml of ethyl benzoate was used. Note that the titanium content in the solid content at this time was 3.19% 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 drying was carried out under reduced pressure to a degree of vacuum of 0.5 torr. In addition,
The titanium content in the solid content at this time was 3.56% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 4 An experiment was conducted in the same manner as in Example 1, except that the temperature of TiCl ₄ was kept at room temperature when pumping the suspension.
Note that the titanium content in the solid content at this time was 3.36% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 5 An experiment was conducted in the same manner as in Example 1 except that magnesium laurate was used instead of magnesium stearate. Note that the titanium content in the solid content at this time was 3.48% 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. Then n-heptane
Washing with 1000 ml was repeated, 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. [Polymerization] 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】

【table】 [Brief explanation of the drawing]

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

Claims (1)

[Claims] 1. (a) fatty acid magnesium, (b) dialkoxymagnesium, and (e) carboxylic acid ester are charged in (c) liquid halogenated hydrocarbon to form a suspension, and the suspension is heated under reflux. The composition obtained by contacting (d) titanium halide represented by the general formula TiX ₄ (in the formula, X is a halogen element) while stirring at a reduced pressure of 0.01 to 1.0 torr. 1. A method for producing a catalyst component for polymerizing olefins, which comprises drying the catalyst component under a vacuum and then bringing it into contact with the titanium halide again.