JPH0535172B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for high-temperature and high-pressure polymerization of ethylene. (Prior art and its problems) A solid catalyst component and an organoaluminum compound containing magnesium, a halogen, and a transition metal as essential components, such as trialkylaluminum,
Using a catalyst obtained from dialkyl aluminum chloride, ethylene or a mixture of ethylene and α-olefin is heated at a temperature of 125° C. or higher at 250° C.
Methods of polymerization in the presence of hydrogen at pressures above Kg/cm ² are known. In the above method, when trialkylaluminum is used as the organoaluminum compound, ethane is produced as a by-product through hydrogenation of ethylene. Therefore, dialkylaluminum chloride is often used industrially as the organoaluminum compound.
Although the use of dialkylaluminum chloride does not produce ethane as a by-product, it has the disadvantage of increasing the halogen content in the resulting polymer, which is another problem. In JP-A-58-21047 and JP-A-58-40305, as an organoaluminum compound used in combination with the solid catalyst component described above, the formula
(R ³ ) ₃ -Si-O-Al-(R ³ ) ₂ (wherein, R ³ is carbon number 1
~10 saturated hydrocarbon groups. ) are described. As can be seen from the results of comparative examples described below, this alkylsiloxane derivative does not substantially exhibit a promoter effect in the high-pressure, high-temperature polymerization of ethylene. (Means for Solving the Problems) According to the present invention, polyethylene can be obtained with good productivity even under high temperature and high pressure, the halogen content in the obtained polyethylene is small, and the by-product of ethane is substantially not observed. Provides a method for polymerizing ethylene. The present invention uses ethylene or a mixture of ethylene and an α-olefin having 3 or more carbon atoms, a solid catalyst component containing magnesium, a halogen, and a transition metal as essential components, the transition metal being titanium and/or vanadium, and a solid catalyst component having the formula R ¹ ₂ Si(OAlR ² ) ₂ (wherein R ¹ and R ² are hydrocarbon groups having 1 to 20 carbon atoms) in the presence of a catalyst obtained from an aluminum compound at a temperature of 125°C or higher. ,
This is an ethylene polymerization method characterized by polymerization at a pressure of 250 kg/cm ² or higher. The solid catalyst component used in the present invention contains magnesium, halogen, and transition metal as essential components. The solid catalyst component can be obtained by a method known per se, for example, by contacting a magnesium-containing solid with a transition metal compound. Examples of magnesium-containing solids include magnesium halides, hydroxymagnesium halides, magnesium oxides, dihydroxymagnesiums, dialkoxymagnesiums, and magnesium oxides, dialkoxymagnesiums, magnesium carboxylates, and the like treated with halogen-containing compounds. Other examples include organomagnesium compounds such as alkylmagnesium halides, dialkylmagnesiums, complexes of dialkylmagnesiums and trialkylaluminiums, or complexes thereof, which are treated with halogen-containing compounds. Examples of the above-mentioned halogen-containing compounds include aluminum halide, silicon halide, alkoxysilane halide, alkylsilane halide,
Alkyl aluminum halide, tin halide,
Examples include reaction products of titanium tetrahalide, aluminum halide, or tin halide and alkylsilane alkoxide or arylsilane alkoxide. As transition metal compounds, compounds of titanium or vanadium are used. Examples of titanium compounds include the formula TiXm( ^OR4 ) ₄ -m (wherein, X represents a halogen atom, ^R4 represents an alkyl group having 1 to 6 carbon atoms, and m is a number from 0 to 4). ), or the formula PlTiX ₄ -l (in the formula, P represents an alkyl group having 4 to 7 carbon atoms, X represents a halogen atom, and l represents 1
The number is ~4. ) can be mentioned. Examples of vanadium compounds include vanadium trihalide, vanadium tetrahalide, vanadium oxydihalide, and vanadium oxytrihalide. The amount of transition metals in the solid component is 0.5-15% by weight
It is preferable that There are no particular restrictions on the method of bringing the magnesium-containing solid and the transition metal compound into contact, and methods include co-pulverizing them, contacting them in a slurry state in the presence of an inert organic solvent, and bringing homogeneous solutions of both components into contact with each other. A method known per se, such as a method of precipitating a solid by a precipitation method, can be employed. The aluminum compound used in the present invention can be obtained by reacting an organoaluminum compound and a silanol according to a method known per se. As an aluminum compound, excellent ethylene polymerization activity is shown only when a compound in the above formula where n is 2 or 3 is used, and when a compound where n is 1 is used, substantially no ethylene polymerization activity is shown. . Specific examples of the aluminum compound used in the present invention include bis(dimethylaluminum)diphenylsilanediolate, bis(diethylaluminum)diphenylsilanediolate, bis(diisobutylaluminum)diphenylsilanediolate, bis(dimethylaluminum)diphenylsilanediolate, bis(dimethylaluminum)diphenylsilanediolate, Dihexylaluminum) diphenylsilanediolate, bis(dimethylaluminum)methylphenylsilanediolate, bis(diethylaluminum)methylphenylsilanediolate, and bis(diisobutylaluminum)methylphenylsilanediolate. In the present invention, ethylene or a mixture of ethylene and an α-olefin having 3 or more carbon atoms is polymerized in the presence of a solid catalyst component, an aluminum compound, and, if necessary, a catalyst obtained from an electron donor. A polymer or ethylene copolymer is obtained. In the present invention, by using an electron donor in combination, the production amount of ethylene polymer is increased.
Examples of electron donors include ethers, esters,
ketones, alcohols, phenols, aldehydes,
Examples include amines, sulfides, and phosphines.
The amount of electron donor used is preferably 0.05 to 0.5 mol per gram atom of aluminum in the aluminum compound. Specific examples of α-olefins having 3 or more carbon atoms include propylene, butene-1, 4-methylpentene-1, and octene-1. Polymerization pressure is 250Kg/ ^cm2 or more, preferably 500~
It is 3000Kg/ ^cm2 . The polymerization temperature is 125°C or higher, preferably 150-350°C. The average residence time of the monomer in the polymerization system is 2 to 600 seconds, preferably 10 to 150 seconds.
Seconds. As the polymerization apparatus, a tubular reactor or a tank reactor can be used. The molecular weight of the produced polyethylene can be easily controlled by adding a molecular weight regulator, such as hydrogen, to the polymerization system. Next, examples and comparative examples will be shown. In the following,
"Polymerization activity" means the production amount (Kg) of ethylene polymer per 1g of titanium of the solid catalyst component used in the polymerization reaction, and "MI" means the production amount (Kg) of ethylene polymer per 1g of titanium used in the polymerization reaction. This is the melting index of ethylene polymer measured at Examples 1 to 3 (1) Preparation of solid catalyst component 15 moles of methyltriethoxysilane were added to toluene slurry 40 containing 15 moles of anhydrous aluminum chloride, and the mixture was reacted at 18°C for 2 hours. Thereafter, the temperature was raised to 30°C and the reaction was continued for 2 hours. The reaction mixture was cooled to −12° C., and 2.5 mol of a diisopropyl ether solution 18 containing 30 mol of n-butylmagnesium chloride was added.
Added over time. The temperature was raised to 30°C and the mixture was reacted for 2.5 hours. Toluene slurry of 4.9Kg of precipitated carrier
Add 150 mol of titanium tetrachloride to 30 and heat at 90℃.
The reaction was allowed to proceed for 30 minutes. The reaction solid was filtered off at 90°C and washed with toluene. Mineral oil was added to the solid catalyst component thus obtained to form a slurry of 12.3 g/ml. The Ti content of the solid catalyst component was 5.2% by weight. (2) Preparation of aluminum compound Toluene slurry 42 containing 111 mol of diphenylsilanediol was cooled to -10°C, and toluene solution 15 containing 222 mol of trimethylaluminum was added dropwise thereto. After dropping, react at the same temperature for 1 hour,
The reaction was further carried out at 60°C for 48 hours to obtain a toluene solution (1.95 mol/) of bis(dimethylaluminum)diphenylsilanediolate. (3) Polymerization A monomer consisting of 54% by weight of ethylene and 46% by weight of butene-1 and 0.45% by volume of hydrogen relative to the monomer were continuously supplied to a reaction tube with a total length of 400m.
Ethylene and butene-1 were copolymerized under a pressure of 2000 Kg/cm ² . The solid catalyst component slurry and the toluene solution of bis(dimethylaluminum)diphenylsilanediolate were continuously fed through an injection point provided at the inlet of the reaction tube at a rate of 16/hour and 10/hour, respectively. The temperature inside the reaction tube is 140℃ at the inlet.
The maximum temperature was maintained at 250℃. The flow rate of the monomer in the reaction tube was 10 m/sec. A mineral oil slurry of zinc stearate (concentration: 0.45 mol/min) was added as a stopper through the injection point provided at the outlet of the reaction tube.
) was injected at a rate of 5/hour. The above continuous operation was performed for 3 hours to obtain an ethylene/butene-1 copolymer. The MI, density and polymerization activity of the above copolymers are shown in Table 1. Comparative Example 1 (1) Preparation of aluminum compound A toluene slurry 60 containing 111 mol of trimethylsilanol was cooled to -10°C, and a toluene solution 16 containing 111 mol of trimethylaluminum was added dropwise thereto. After completion of the dropwise addition, the mixture was reacted at the same temperature for 1 hour to obtain a toluene solution (1.44 mol/) of dimethylaluminum trimethylsilanolate. (2) Polymerization The same method as in Example 1 was repeated except that a toluene solution of dimethylaluminum trimethylsilanolate was fed at a rate of 10/hour. The results are shown in Table 1. Example 2 (1) Preparation of solid catalyst component 1.9 kg of commercially available anhydrous magnesium chloride and 342 g of ethyl benzoate were co-pulverized in a vibrating ball mill for 5 hours. The pulverized material was made into a slurry of 30% toluene.
Add 15% titanium tetrachloride to this slurry and 90% titanium tetrachloride.
The reaction was carried out at ℃ for 1 hour. After the reaction was completed, the solid catalyst component was filtered and washed to obtain a mineral oil slurry (15.3 g/). The titanium content in the solid catalyst component was 3.2% by weight. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that the solid catalyst component slurry was fed at a rate of 20/hour. The results are shown in Table 1. Example 3 (1) Preparation of solid catalyst component 3.1Kg of magnesium 2-ethylhexanoate
- A heptane solution of 2.4 kg of diethylaluminum chloride in a heptane slurry (200 g/)
mol/) at room temperature to precipitate the carrier,
Filtered and washed. 15 mol of titanium tetrachloride was added to the n-heptane slurry of the carrier, and the mixture was reacted at 90°C for 1 hour. After the reaction was completed, the solid catalyst component was filtered and washed to obtain a mineral oil slurry (12.5 g/). The titanium content in the solid catalyst component was 5.1% by weight. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that the solid catalyst component slurry was fed at a rate of 20/hour. The results are shown in Table 1. Example 4 (1) Preparation of solid catalyst component 4.5 kg of silicon tetrachloride was added dropwise to n-heptane slurry (0.25 kg/) containing 2.5 kg of diethoxymagnesium and reacted. After the reaction was completed, the carrier was filtered and washed. . 15 titanium tetrachloride was added to the n-heptane slurry containing 2.1 kg of carrier, and the mixture was reacted at 90°C for 1 hour. After the reaction is completed, the solid catalyst component is filtered and washed,
It was made into mineral oil slurry (15.5g/).
The titanium content in the solid catalyst component was 3.4% by weight. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that the solid catalyst component slurry was fed at a rate of 20/hour. The results are shown in Table 1.

[Table] Example 5 (1) Preparation of solid catalyst component Trichlorobutoxytitanium was added to 4.8 kg of toluene slurry 30 of the carrier obtained in the same manner as in Example 1.
150 mol was added and reacted at 90°C for 30 minutes. After the reaction was completed, the solid catalyst component was filtered and washed to obtain a mineral oil slurry (13.8 g/). The titanium content in the solid catalyst component was 3.4% by weight. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1 except that the solid catalyst component slurry was fed at a rate of 20/hour. The results are shown in Table 2. Example 6 (1) Preparation of solid catalyst component 10.78 mol of trichlorooxyvanadium was added to toluene slurry 30 containing 4.9 kg of carrier obtained in the same manner as in Example 1, and the mixture was reacted at 90°C for 30 minutes.
After the reaction was completed, the solid catalyst component was filtered and washed to obtain a mineral oil slurry (12.0 g/). The titanium content in the solid catalyst component was 5.0% by weight. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1 except that the solid catalyst component slurry was fed at a rate of 20/hour. The results are shown in Table 2. Example 7 (1) Preparation of solid catalyst component 175 moles of titanium tetrachloride and 8.75 moles of trichlorooxyvanadium were added to 4.9 kg of toluene slurry 30 of the carrier obtained in the same manner as in Example 1.
The reaction was carried out at 90°C for 30 minutes. After the reaction was completed, the solid catalyst component was filtered and washed to obtain a mineral oil slurry (12.5 g/). The content of titanium and vanadium in the solid catalyst component is 4.3% by weight, respectively.
and 3.8% by weight. (2) Polymerization Ethylene was copolymerized with butene-1 in the same manner as in Example 1, except that the solid catalyst component slurry was fed at a rate of 15/hour. The results are shown in Table 2.

[Table] Example 8 (1) Preparation of aluminum compound Toluene slurry 42 containing 111 mol of diphenylsilanediol was cooled to -10°C, and toluene solution 15 containing 222 mol of triethylaluminum was added dropwise thereto. After completing the dropwise addition, react at the same temperature for 1 hour,
The reaction was further carried out at 60° C. for 48 hours to obtain a toluene solution (1.95 mol/) of bis(diethylaluminum)diphenylsilanediolate. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that a toluene solution of bis(diethylaluminum)diphenylsilanediolate was fed at a rate of 10/hour. The results are shown in Table 3. Example 9 (1) Preparation of aluminum compound A toluene slurry 63 containing 111 mol of diphenylsilanediol was cooled to -10°C, and a toluene solution 15 containing 222 mol of triisobutylaluminum was added to the slurry 63 in toluene containing 111 mol of diphenylsilanediol.
was dripped. After completion of the dropwise addition, the mixture was reacted at the same temperature for 1 hour and further at 60° C. for 48 hours to obtain a toluene solution (1.42 mol/) of bis(diisobutylaluminum)diphenylsilanediolate. (2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that a toluene solution of bis(diisobutylaluminum)diphenylsilanediol was fed at a rate of 20/hour. The results are shown in Table 3.

【table】 [Brief explanation of the drawing]

FIG. 1 shows a flowchart of the manufacturing process of the catalyst of the present invention.

Claims (1)

[Claims] 1. Ethylene or ethylene and α- having 3 or more carbon atoms
A solid catalyst component containing magnesium, a halogen and a transition metal as essential components, the transition metal being titanium and/or vanadium, and a solid catalyst component of the formula R ¹ ₂ Si(OAlR ² ) ₂ (wherein R ¹ and ^R2 are hydrocarbon groups having 1 to 20 carbon atoms.) at a temperature of 125°C or higher,
An ethylene polymerization method characterized by polymerization at a pressure of 250Kg/cm2 or ^higher .