JPH0415809B2 - - 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, the present invention relates to a method for producing a catalyst component for polymerizing olefins, which comprises contacting fatty acid magnesium, dialkoxymagnesium, an electron donating substance, and 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 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, 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. Therefore, attempts have 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. As an example, in JP-A-49-120980, a catalyst component is obtained by reacting magnesium acetate with an aluminum compound, and then contacting the reaction product with titanium tetrahalide in a liquid phase. Although a method for polymerizing olefins has been disclosed, it is not applicable to propylene polymerization, which requires a high yield of stereoregular polymers, as in the present invention. This fact is also demonstrated in the comparative examples described below. 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 features of the present invention include (a) magnesium stearate, (b) dialkoxymagnesium, (c) an electron donating substance, and (d) a compound of the general formula TiX ₄ (wherein X is a halogen element). The composition obtained by contacting with a titanium halide represented by .) is further contacted with the titanium halide and used as a catalyst component for polymerizing olefins,
By using such a method, the performance is dramatically improved compared to the case where magnesium stearate or dialkoxymagnesium is used alone. Further, there is no known example of preparing an industrially useful catalyst component by combining magnesium stearate and dialkoxymagnesium. 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. and had the disadvantage that the stereoregularity was greatly 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. Note that it is preferable to use the magnesium stearate and dialkoxymagnesium in a form with as much moisture removed as possible. Examples of electron-donating substances used in the present invention include aliphatic carboxylic acid esters such as ethyl acetate and methyl methacrylate, aromatic carboxylic acid esters such as ethyl toluate, ethyl anisate, and ethyl benzoate. However, among these, aromatic carboxylic acid esters are preferred, and among these, ethyl benzoate, ethyl p-anisate, and ethyl p-toluate are particularly 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 proportion of each of these components used is arbitrary as long as it does not adversely affect the performance of the catalyst component produced, and is not particularly limited. 0.01 to 10 g of sexual substance, preferably 0.1 to 1 g, and 0.1 g of titanium halide
The above amount is preferably used in a range of 5 g or more. At this time, the order and method of contacting each component are not particularly limited, but magnesium stearate and dialkoxymagnesium may be suspended in an aromatic hydrocarbon and then added to the titanium halide; Preferably, the alkoxymagnesium is suspended in an aromatic hydrocarbon and then added to the titanium halide with magnesium stearate. Note that in the above method, the electron-donating substance can be used at any point. At this time, the suspension is maintained in a suspended state at a temperature of, for example, from 0°C to the boiling point of the aromatic hydrocarbon used, usually for 10 hours or less, preferably for 3 hours or less, and then heated to 140°C or less, preferably is added to the titanium halide or the mixture of the titanium halide and magnesium stearate at a temperature of 100°C or less, and then the temperature range is usually from room temperature to the boiling point of the titanium halide used, preferably in the temperature range from 70°C to 100°C. to cause a contact reaction. The contact reaction time is arbitrary as long as each of the above components present can sufficiently react, but it is usually 10 minutes or more.
The range is 100 hours. Incidentally, as the aromatic hydrocarbon used at this time, benzene, toluene, xylene, etc. are preferable. The composition obtained after the contact is further contacted with a titanium halide. It is also possible to wash using an organic solvent such as n-heptane. 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, 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] 5 g of magnesium stearate, 5 g of diethoxymagnesium, 2.5 ml of ethyl benzoate and 50 ml of toluene were charged into a 200 ml round bottom flask that was sufficiently purged with nitrogen gas and equipped with a stirrer. The mixture was stirred under reflux for 2 hours 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 and heated to 90° C.
The temperature was raised to 100%, and the mixture was reacted with stirring for 2 hours. After the reaction was completed, the solution was washed 10 times with 200 ml of n-heptane at 40°C.
Another 200 ml of TiCl ₄ was added, and the mixture was reacted at 90°C for 2 hours with stirring. After the reaction was completed, the mixture was cooled to 40° C., and then washed repeatedly with 200 ml of n-heptane. 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 a stirring device and an internal volume of 2.0 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 2.0 ml of ethyl benzoate was used. Note that the titanium content in the solid content at this time was 3.88% 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 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 3.69% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 4 Example 1 except that the treatment temperature of TiCl ₄ was 80°C
The catalyst components were prepared in the same manner as above. In addition,
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. Example 5 5 g of diethoxymagnesium and 25 ml of toluene were charged into a 100 ml round bottom flask, which was sufficiently purged with nitrogen gas and equipped with a stirrer, to form a suspension.
Stirred under reflux for 2 hours. On the other hand, 5 g of magnesium stearate, 2.5 ml of ethyl benzoate, and 200 ml of TiCl ₄ were placed in a 500 ml round bottom flask that was sufficiently purged with nitrogen gas and equipped with a stirrer, and reacted with stirring at room temperature for 1 hour. , then 0℃
It was cooled to Next, the suspension was pumped into this, the temperature was raised to 90°C, and the reaction was stirred for 2 hours. After the reaction was completed, the solution was washed 10 times with 200 ml of n-heptane at 40°C.
Another 200 ml of TiCl ₄ was added, and the mixture was stirred and reacted at 90°C for 2 hours. After the reaction was completed, it was cooled to 40°C and further
- Repeated washing with 200 ml of heptane,
The cleaning was completed when chlorine was no longer detected in the cleaning solution, and a catalyst component was obtained. Note that the titanium content in the solid content at this time was 3.34% by weight. The polymerization was conducted in the same manner as in Example 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. 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. Comparative Example 2 14.2 g of anhydrous magnesium acetate, 40.8 g of aluminum triisopropoxide, and 50 ml of decalin were placed in a 200 ml round bottom flask under a nitrogen atmosphere, and a stirring reaction was carried out at 170 to 230°C for 10 hours. Ta. Thereafter, the solvent was removed and drying was performed under reduced pressure to obtain a solid powder. The obtained solid powder was washed 10 times with 100 ml of dehydrated n-heptane, the solvent was removed, and the powder was further dried under reduced pressure to obtain a solid powder. Next, 80 ml of TiCl ₄ was added thereto, the mixture was heated to 150°C, and a stirring reaction was carried out for 2 hours. After the reaction was completed, the mixture was cooled to room temperature, left to stand, and the supernatant liquid was removed by decantation. Then dehydration
- Repeated washing with 100 ml of heptane;
The cleaning was completed when chlorine was no longer detected in the cleaning solution, and the cleaning solution was used as a catalyst component. At this time, the solid-liquid in the catalyst component was separated and the titanium content of the solid component was measured and found to be 12.2% by weight. During polymerization, the catalyst components obtained were 1.62 mg of titanium atoms, 109 mg of triethylaluminum,
An experiment was carried out in the same manner as in Example 1 by charging 35 mg of ethyl p-toluate. The results are shown in Table 1, but no polymer was obtained whose polymerization properties could be measured. 【table】

Claims (1)

[Claims] 1 (a) Magnesium stearate, (b) dialkoxymagcisium, (c) electron donor and (d) titanium halide represented by the general formula TiX ₄ (in the formula, X is a halogen element) A method for producing a catalyst component for the polymerization of orpheins, which comprises further contacting the composition obtained by contacting the titanium halide with the titanium halide.