JPH0425283B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that when subjected to polymerization of α-olefins,
A method for producing a high-performance catalyst component that acts with high activity and can obtain a stereoregular polymer in high yield. The present invention relates to a method for producing a catalyst component for polymerizing α-olefins, which comprises suspending the catalyst component in hydrogen and then contacting it with a titanium halide. Conventionally, solid titanium halides have been well known and widely used as catalyst components for the polymerization of α-olefins. Since the polymerization activity per titanium is low, a so-called demineralization step to remove catalyst residues was unavoidable. Since this deashing process uses a large amount of alcohol or chelating agent, recovery equipment or regeneration equipment for these is essential, and there are many problems related to resources, energy, etc., and those skilled in the art should solve them as soon as possible. This was an important issue that needed to be addressed. 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, there is a recent trend in which transition metal compounds such as titanium halides, which are active ingredients, are supported on carrier materials such as magnesium chloride, and when used in the polymerization of α-olefins, the polymerization activity per titanium in the catalyst component is dramatically increased. There are many proposals for increasing the number of targets. 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 not only causes deterioration and yellowing of the produced polymer, but also causes corrosion of equipment used in processes such as granulation and molding, and as a result, the effects of chlorine in fact However, to date, none of the catalyst components using magnesium chloride as a carrier material disclosed in the above-mentioned publications has been obtained that exhibits sufficient performance. The current situation is that there is no such thing. Therefore, attempts have been made to use substances other than magnesium chloride in order to obtain higher performance. For example, in JP-A-56-166205, Mg
(OR') _o X _2-o (R' represents an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 10 carbon atoms, X represents a halogen atom, and n is 1.0 to 2.0
shows. ) is disclosed. However, with this method, Ti(OR ² ) ₄ (R ²
represents an alkyl group, cycloalkyl group, aryl group or aralkyl group having 1 to 10 carbon atoms. ) is required, and in terms of performance, no one has been obtained that satisfies the requirements of the technical field. In addition, in JP-A No. 57-40510, metal magnesium, tetraalkoxy titanium, alcohol,
A method for obtaining a catalyst component by reacting an electron-donating compound and a titanium halide has been disclosed, but it is necessary to start the reaction from metallic magnesium, and the use of tetraalkoxytitanium is also an essential requirement. Moreover, it does not show sufficient performance values. Furthermore, in Japanese Patent Application Laid-open No. 57-63309,
Mg(OR') ₂ (R' represents an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms) is brought into contact with an electron-donating compound, and then Ti(OR ² ) _o X _{4 -o} ( ^R2 represents an alkyl group, cycloalkyl group, aryl group, alkenyl group, or aralkyl group having 1 to 10 carbon atoms, n is a real number from 0 to 4, and X represents a halogen atom.) Although a method for obtaining a catalyst component by carrying out the reaction two or more times has been disclosed, it has not yet reached the point where it can fully satisfy the requirements of the technical field in terms of polymerization characteristics and the like. There is also a description that an aliphatic hydrocarbon such as hexane or heptane can be added as a solvent when bringing the Mg(OR') ₂ into contact with an electron-donating compound, but as shown in the comparative example below, It cannot be said that it shows sufficient performance. As a result of intensive research to solve the problems remaining in the conventional technology, the present inventors have developed the general formula Mg(OR) ₂
(wherein R is an alkyl group, a cycloalkyl group, or an aryl group) in the presence of a carboxylic acid ester,
suspended in toluene and/or xylene;
Thereafter, by further contacting the titanium halide with the composition obtained by contacting the titanium halide represented by the general formula TiX ₄ (wherein X is a halogen element), the catalytic performance was dramatically improved. I was able to improve it. 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. Further, as an accompanying effect, the produced polymer is characterized by being approximately spherical, having a narrow particle size distribution, and having a large particle size. For this reason, handling of the produced polymer, such as transporting it to a post-processing device, has become extremely easy. Currently, there is an urgent need in the industry to omit the granulation step in the industrial production process of α-olefin polymers. This opens the possibility of omitting the grain process. In addition, in the industrial production of α-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 cannot be used in the coexistence of hydrogen. However, it had the disadvantage that the activity and stereoregularity were greatly reduced. However, when α-olefins are polymerized using the catalyst component obtained according to the present invention, the activity and stereoregularity hardly decrease even when hydrogen is present during the polymerization.
Such an effect 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. It will be done. 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. 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 0.01 to 2 g of carboxylic acid esters are used per 1 g of alkoxymagnesium. It is preferably in the range of 0.1 to 1 g, and the titanium halide is used in an amount of 0.1 g or more, preferably 1 g or more. Further, toluene and/or xylene may be used in any proportion as long as it can form a suspension. In the present invention, suspension of alkoxymagnesium in toluene and/or xylene in the presence of a carboxylic acid ester is usually carried out at room temperature or up to the boiling point of the toluene and/or xylene used for up to 100 hours, preferably up to 10 hours. It is done within a range. At this time, it is necessary that the suspension does not become a homogeneous solution. The suspension and the titanium halide are brought into contact at a temperature of usually -20°C to the boiling point of the titanium halide used, preferably -10°C to 100°C, for a period of 10 minutes to 10 hours. At this time, it is preferable to add the suspension to the titanium halide. The means for contacting each component in the present invention is not particularly limited as long as each component can be brought into sufficient contact with each other.
This is usually carried out while stirring using a container equipped with a stirrer. In the present invention, it is also possible to suspend alkoxymagnesium in a toluene and/or xylene solvent in the presence of a carboxylic acid ester, then contact it with a titanium halide, and then wash it with an organic solvent such as n-heptane. Furthermore, repeated contact with titanium halide is not prohibited. 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 α-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 α-olefin monomer can be used in either gas or liquid state. Polymerization temperature is below 200℃, preferably 100℃
The polymerization pressure is 100 kg/cm ² ·G or less, preferably 50 kg/cm ² ·G or less. The α-olefins that can be homopolymerized or copolymerized using the catalyst component produced by the method of the present invention include propylene, 1-butene, 4-methyl-1-pentene, etc. Copolymerization is also possible. The present invention will be specifically explained below using Examples and Comparative Examples. Example 1 [Preparation of catalyst components] 5 g of diethoxymagnesium, 2.0 ml of ethyl benzoate, and toluene were placed in a 200 ml round bottom flask that was sufficiently purged with nitrogen gas and equipped with a stirrer.
25 ml of the solution was added to form a suspension, and the mixture was stirred at 70°C for 1 hour. This suspension is then poured into a volume equipped with a stirrer.
The mixture was pumped into 200 ml of TiCl ₄ at 0° C. in a 500 ml round-bottomed flask, heated to 70° C., and reacted with stirring for 2 hours. After the reaction is complete, add 300ml of n-heptane at 40°C.
Wash twice, add 150 ml of TiCl ₄ and heat at 70℃ for 2 times.
The reaction was allowed to take place while stirring for hours. 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 3.89% 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 the catalyst component is 1.0 as a titanium atom.
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(%). Further, residual chlorine in the produced polymer is represented by (G), and MI of the produced polymer is represented by (H). The results obtained are shown in Table 1. Example 2 An experiment was conducted in the same manner as in Example 1 except that 3.0 ml of ethyl benzoate was used. Note that the titanium content in the solid content at this time was 3.60% 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 3.26% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 4 5 g of diethoxymagnesium and ethyl benzoate
The experiment was carried out in the same manner as in Example 1, except that the suspension consisting of 2.0 ml and 25 ml of toluene was stirred and the subsequent reaction with TiCl ₄ was carried out at 80°C. Note that the titanium content in the solid content at this time was 3.81% by weight. During the polymerization, an experiment was carried out in the same manner as in Example 1, except that 0.5 mg of the catalyst component was charged as titanium atoms. The results obtained are shown in Table 1. Example 5 An experiment was conducted in the same manner as in Example 1 except that 0-xylene was used instead of toluene. Note that the titanium content in the solid content at this time was 3.22% 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 An experiment was conducted in the same manner as in Example 1 except that n-heptane was used instead of toluene. In addition,
The titanium content in the solid content at this time was 2.56% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Comparative Example 2 5 g of diethoxymagnesium, 2.0 ml of ethyl benzoate and 25 ml of TiCl ₄ were placed in a 200 ml round bottom flask that was sufficiently purged with nitrogen gas and equipped with a stirrer.
was charged and reacted at 70°C for 1 hour with stirring. Next, the mixture was pumped into 200 ml of TiCl ₄ at 0° C. in a 500 ml round bottom flask equipped with a stirrer, heated to 70° C., and reacted with stirring for 2 hours. After the reaction
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. In addition, when the titanium content in the solid content at this time was measured, it was 3.99% by weight. The polymerization was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. 【table】

[Brief explanation of drawings]

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

Claims (1)

[Claims] 1 (a) General formula Mg(OR) ₂ (wherein R is an alkyl group,
It is a cycloalkyl group or an aryl group. ) is suspended in (c) toluene and/or xylene in the presence of (b) a carboxylic acid ester, and then (d) the general formula
For polymerization of α-olefins, which comprises contacting a titanium halide represented by TiX ₄ (wherein X is a halogen element), and further contacting the resulting composition with the titanium halide. Method for producing catalyst components.