JPS61176612A - Ethylene polymerization method - Google Patents

Abstract

PURPOSE:To obtain the titled polymer with a low halogen content in high productivity without forming ethane as a by-product, by polymerizing ethylene, etc., in the presence of a catalyst consisting of a solid catalyst component containing Mg, a halogen and transition metal and a specific Al compound at a high temperature under a high pressure. CONSTITUTION:Ethylene or a mixture thereof with a >=3C alpha-olefin is polymerized in the presence of a catalyst obtained from a solid catalyst component containing magnesium, a halogen and transition metal as essential components and an aluminum compound, e.g. expressed by the formula R<1>4-nSi(OAlR<2>)n (R<1> and R<2> are 1-20C hydrocarbon group; n is 2 or 3), e.g. bis(dimethylaluminum)diphenylsilane dioleate, at >=125 deg.C under >=250kg/cm<2> pressure to give the aimed polymer.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a high temperature and high pressure polymerization method for ethylene.

(Prior art and its problems) Ethylene or A method is known in which a mixture with an α-olefin is polymerized in the presence of hydrogen at a temperature of 125° C. or higher and a pressure of 25 Q kg/cJ or higher.

In the above method, when trialkylaluminum is used as the organoaluminum compound, ethane is produced as a by-product through hydrogenation of ethylene, so dialkylaluminum chloride is often used industrially as the organoaluminum compound.

When dialkyl aluminum chloride is used, although no ethane is produced as a by-product, another problem arises: the resulting polymer has a high halogen content.

JP-A-58-21047 and JP-A No. 58-40305
The publication describes the formula (R)J as an organoaluminum compound used in combination with the solid catalyst component described above.
An alkylsiloxane derivative represented by S t OAN (R')z (in the formula, ♂ is a saturated hydrocarbon group having 1 to 10 carbon atoms) is described. This alkylsiloxane derivative does not substantially exhibit a cocatalyst effect in the high-pressure, high-temperature polymerization of ethylene, as seen from the results of comparative examples described below.

(Means for solving the problems) The present invention has the following features: 1. 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 eliminated. The present invention provides a method for polymerizing ethylene that is difficult to produce.

The present invention provides ethylene or ethylene and α-
A mixture with an olefin, a solid catalyst component containing magnesium, a halogen, and a transition metal as essential components, and a formula R4-nSi (OA/R) n (where d and R2 are hydrocarbon groups having 1 to 20 carbon atoms) and n is 2 or 3), at a temperature of 125° C. or higher and a pressure of 250 kg/c+a or higher. It's legal.

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, it can be obtained by contacting a magnesium-containing solid with a transition metal compound.

Examples of magnesium-containing solids include magnesium halides, hydroxymagnesium halide, magnesium oxide, dihydroxymagnesium, dialkoxymagnesium, and magnesium oxide, dialkoxymagnesium, magnesium carboxylate, etc. treated with halogen-containing compounds. Can be mentioned. 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 2. Aluminum halide, silicon halide, alkoxysilane halide, alkylsilane halide, alkyl aluminum halide, tin halide, titanium tetrahalide, reaction product of aluminum halide or tin halide with alkylsilane alkoxide or arylsilane alkoxide Can be mentioned.

Among the transition metal compounds, titanium or vanadium compounds are preferably used.

Examples of titanium compounds include the formula T i Xm (OR')4-m (wherein, ), or 2 Pj? TiX+-f (in the formula, P represents an alkyl group having 4 to 7 carbon atoms, X represents a halogen atom, and l represents 1 to 4
is the number of ) can be mentioned.

Examples of vanadium compounds include vanadium trihalide, vanadium tetrahalide, vanadium oxytrihalide, and vanadium oxytrihalide.

Preferably, the amount of transition metal in the solid component is between 0.5 and 15% by weight.

There are no particular restrictions on the method of bringing the magnesium-containing solid and the transition metal compound into contact, and they may be co-pulverized, brought into contact in a slurry state in the presence of an inert organic solvent, or brought into contact with a homogeneous solution of both components. 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. Showing excellent ethylene polymerization activity only when using a compound in which n is 2 or 3 in the above formula as the aluminum compound,
When a compound in which n is 1 is used, it does not substantially exhibit ethylene polymerization activity.

Specific examples of the aluminum compound used in the present invention include bis(dimethylaluminum)diphenylsilanediolate, bis(diethylaluminum)diphenylsilanediolate, bis(diisobutylaluminum)diphenylsilanediolate, bis(diethylaluminum)diphenyl Silanediolate, bis(dimethylaluminum)methylphenylsilanediolate, bis(diethylaluminum)methylphenylsilanediolate, bis(diisobutylaluminum)methylphenylsilanediolate, tris(dimethylaluminum)phenylsilanetriolate, and tris( (diethylaluminum) phenylsilanetriole F.

In the present invention, in the presence of a solid catalyst component, an aluminum compound, and if necessary a catalyst obtained from an electron donor, ethylene or ethylene and α-
The mixture with olefins is polymerized to obtain ethylene homopolymers or ethylene copolymers.

In the present invention, the production amount of ethylene polymer is increased by using an electron donor in combination.

Examples of electron donors include ethers, esters, ketones, alcohols, phenols, aldehydes, amines, sulfides, 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.

The polymerization pressure is 250 kg/cII1 or more, preferably 50 kg/cII1 or more.
It is 0 to 3000 kg/cd. The polymerization temperature is 125°C or higher, preferably 150 to 350°C. The average residence time of the monomer within the polymerization system is 2 to 600 seconds, preferably 1
It is 0 to 150 seconds.

As the polymerization apparatus, a tube reactor or a seed reactor can be used.

The molecular weight of the polyethylene produced 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 1 g of titanium in the solid catalyst component used in the polymerization reaction, and rMIJ is 2.16 in accordance with ASTM D1238.
Melt index of ethylene polymer measured at 190° C. under a load of kg.

Examples 1 to 3 (1) Preparation of solid catalyst component Toluene slurry 4 (15 mol of anhydrous aluminum chloride)
Add 15 mol of methyltriethoxysilane to 18
The reaction was carried out for 2 hours at <0>C. Thereafter, the temperature was raised to 30°C and the reaction was continued for 2 hours. The reaction mixture was cooled to -12 DEG C. and 181 of a diisopropyl ether solution containing 30 moles of n-butylmagnesium chloride was added over 2.5 hours.

The temperature was raised to 30°C and the reaction was carried out for 2.5 hours. Precipitated carrier 4
．． 9 kg of toluene slurry 301 to titanium tetrachloride 1
50 mol was added and reacted at 90°C 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/f. T of solid catalyst component
The i content was 5.2% by weight.

(2) Preparation of aluminum compound Toluene slurry 421 containing 111 mol of diphenylsilanediol was cooled to -[0°C, and 15 J of a toluene solution containing 222 mol of trimethylaluminum was added dropwise thereto. After the dropwise addition was completed, the reaction was continued at the same temperature for 1 hour, and then at 60°C for 4 hours.
The reaction was continued for 8 hours to obtain a toluene solution (1.95 mol/N) of bis(dimethylaluminum)diphenylsilanediolate.

(3) Polymerization A monomer consisting of 54 M% of ethylene and 146% of butene by weight, and hydrogen of 0.45% by volume relative to the monomer were continuously supplied to a reaction tube with a total length of 400 m.
Ethylene was copolymerized with butene-1 under pressure of kg/c+a.

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 161/hour and 101/hour, respectively. The temperature inside the reaction tube was maintained at 140°C at the inlet and 250°C at the maximum temperature. The flow rate of the monomer in the reaction tube was 10 m/sec.

A mineral oil slurry of zinc stearate (concentration: 0.4
5 mol/A') was injected at a rate of 56/h.

The above continuous operation was performed for 3 hours to obtain an ethylene/butene-1 copolymer.

The M■, density and polymerization activity of the above copolymers are shown in Table 1.

Comparative Example 1 (1) Preparation of aluminum compound Toluene slurry 6 containing 111 mol of trimethylsilanol
The ON was cooled to -10° C., and 161 mol of a toluene solution containing 111 mol of trimethylaluminum was added dropwise thereto. After the dropwise addition, the reaction was carried out at the same temperature for 1 hour, and a toluene solution of dimethylaluminum trimethylsilate (1.44 mol/N
) was obtained.

(2) The same method as in Example 1 was repeated except that a toluene solution of polymerized dimethylaluminum trimethylsilate was fed at a rate of 101/hour. The results are shown in Table 1.

Example 2 (1) As a solid catalyst component, 1.9 kg of commercially available anhydrous magnesium chloride manufactured by G and 342 g of ethyl benzoate were co-pulverized in a vibrating ball mill for 5 hours.

The pulverized product was made into a slurry of 3ON of toluene. Titanium tetrachloride 151 was added to this slurry and 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 (15.3 g #). The titanium content in the solid catalyst component was 3.2% by weight.

(2) Polymerization Ethylene and polymerization were carried out in the same manner as in Example 1, except that the above solid catalyst component slurry was fed at a rate of 201/hour.

Copolymerization with Ten-1 was carried out.

The results are shown in Table 1.

Example 3 (1) Preparation of solid catalyst component 3.1 kg of magnesium 2-ethylhexanoate n-
A hebutane slurry (200 g/#) was reacted with a hebutane solution (0.5 mol/1) containing 2.4 kg of diethylaluminium chloride at room temperature to precipitate a carrier, which was then filtered and washed. 15 mol of titanium tetrachloride was added to the n-hebutane 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°/l). 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 above solid catalyst component slurry was fed at a rate of 20 l/hour.

The results are shown in Table 1.

Example 4 (1) Preparation of solid catalyst component 2.5 kg of jetoxymagnesium n-hebutane slurry (0.25 kg/β) and 4.5 kg of silicon tetrachloride
was added dropwise to react. After the reaction was completed, the carrier was filtered and washed. Titanium tetrachloride 151 was added to n-hebutane slurry containing 2.1 kg of 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 (15.5 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 above solid catalyst component slurry was fed at a rate of 20 a/hour.

The results are shown in Table 1. - Table 1 "Ljl! -■Mi l Example 1 800 20.6 0.917 Comparative example 1
50 - Example 2 620
1B, 2 0.915〃3 780 19.4 0
．． 916〃4 750 1,9.3 0.920 Example 5 (1) Preparation of solid catalyst component Trichlorobutoxytitanium 150 was added to 4.8 kg of toluene slurry 301 of the carrier obtained in the same manner as in Example 1.
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 form a mineral oil slurry (13.8 g/l).

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 above solid catalyst component slurry was fed at a rate of 20 l/hour.

The results are shown in Table 2.

Example 6 (1) Preparation of solid catalyst component 4.9 kg of toluene slurry 307! trichlorooxyvanadium 1
0.78 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 (12.0 g/A). 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 above solid catalyst component slurry was fed at a rate of 20 l/hr.

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 carrier slurry 306 obtained in the same manner as in Example 1, and the mixture was heated at 90°C.
The mixture was allowed to react for 30 minutes. After the reaction, the solid catalyst component was filtered and washed to form a mineral oil slurry (12.5 g/l).The contents of titanium and vanadium in the solid catalyst component were 4.3% by weight and 3.8% by weight, respectively. Met.

(2) Polymerization Copolymerization of ethylene and butene-1 was carried out in the same manner as in Example 1, except that the above solid catalyst component slurry was fed at a rate of 151/hour.

The results are shown in Table 2.

Table 2 L dish Ml - bean skin = 5 730 18.90.920 6 570 32.50.915 7 765 27.60.917 Example 8 (1) Preparation of aluminum compound Toluene slurry of 111 moles of diphenylsilanediol 42I was cooled to -10°C, and 151 of a toluene solution containing 222 mol of triethylaluminum was added dropwise thereto.

After completion of the dropwise addition, the reaction was carried out at the same temperature for 1 hour, and further at 60° C. for 48 hours to obtain a toluene solution (1.95 mol/I) 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 supplied at 1,011 hours.

The results are shown in Table 3.

Example 9 (1) Preparation of aluminum compound Toluene slurry 6372 containing 111 moles of diphenylsilanediol was cooled to -10°C, and a 15N toluene solution containing 222 moles of triisobutylaluminum was added dropwise thereto. After the addition was completed, the reaction was continued for 1 hour at the same temperature, and then
After reacting at ℃ for 48 hours, a toluene solution of bis(diisobutylaluminum)diphenylsilanediolate (1
, 42 mol/2) was obtained.

(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)diphenylsilanediolate was fed at a rate of 20 1/hour.

The results are shown in Table 3.

Table 3 Next 11...Ml - Hajime Miwatari

Claims (1)

[Scope of Claims] 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, and a solid catalyst component having the formula R^1_4-nSi (OAlR^2 )_n (wherein, R
^1 and R^2 are hydrocarbon groups having 1 to 20 carbon atoms,
n is 2 or 3. ) in the presence of a catalyst obtained from an aluminum compound represented by
A method for polymerizing ethylene, which is characterized by polymerizing at a pressure of 50 kg/cm^2 or more.