JPS6210515B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is used for an olefin polymerization catalyst,
It concerns magnesium chloride. Magnesium chloride is widely used as a carrier for Ziegler catalysts, but conventionally a method has been adopted in which a titanium compound is supported on solid magnesium chloride. The present inventors used magnesium chloride as a solution,
We thought that if we could co-precipitate with titanium tetrahalide, we might be able to obtain a complex useful as a catalyst component for olefin polymerization, and as a result of investigating solutions useful for co-precipitation, we found that a tetrahydrofuran solution of magnesium chloride/tetrahydrofuran complex could be used for the above purpose. We have found that this is true and have achieved the present invention. That is, the gist of the present invention is to produce a tetrahydrofuran solution of a magnesium chloride/tetrahydrofuran complex for co-precipitation, which is represented by the general formula _MgCl2.pY (Y is tetrahydrofuran, 1p2), and is characterized by dissolving magnesium chloride in tetrahydrofuran. It lies in the method. To further explain the present invention, the solution of the present invention comprises:
A tetrahydrofuran complex of magnesium chloride is precipitated by dissolving anhydrous magnesium chloride in tetrahydrofuran (hereinafter sometimes abbreviated as "THF") or from a solution of anhydrous magnesium chloride in tetrahydrofuran, and then the complex is re-precipitated. It can be obtained by dissolving it in tetrahydrofuran. In the present invention, the general formula MgCl ₂ pY (Y is tetrahydrofuran,
A tetrahydrofuran solution of a magnesium chloride/tetrahydrofuran complex represented by 1p2) is used for co-precipitation. There is no particular restriction on the method of adding a titanium compound such as titanium tetrahalide used for co-precipitation. For example, titanium tetrahalide may be added as a tetrahydrofuran solution of a tetrahydrofuran complex of titanium tetrahalide obtained by dissolving titanium tetrahalide in excess tetrahydrofuran, or titanium tetrahalide may be added directly. Titanium tetrachloride is preferably used as the titanium tetrahalide. The ratio of titanium tetrahalide to magnesium chloride is appropriately selected depending on the desired Ti/Mg value in the complex after co-precipitation. In this way, the complex is co-precipitated from the tetrahydrofuran solution obtained in the present invention. This solution is used to co-deposit a complex consisting of, for example, magnesium chloride, titanium tetrahalide, and tetrahydrofuran, but the method is not particularly limited. For example, a method of cooling the solution, a method of adding a poor solvent such as a hydrocarbon, and a method of removing tetrahydrofuran by evaporation can be adopted. According to the present invention, the general formula [MgnTi() _1-o ]X
_n・xY (wherein, X is a halogen atom, Y is tetrahydrofuran, n is 0.01 to 0.99, m is 2<m
<4, x indicates a number of 1<x<3. ) can be easily obtained, and the complex exhibits excellent polymerization activity as a catalyst for olefin polymerization such as ethylene when combined with an organoaluminum compound as a catalyst component for olefin polymerization, and also has a narrow molecular weight distribution. It is an extremely useful polyolefin. EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto unless it exceeds the gist thereof. In addition, the molecular weight distribution (M
_W /M _N ) was determined by the column fraction method. In addition, the measurement method for MI (Melt Index) is ASTM
Measured at 190°C in accordance with D-1238T. Example 1 Using a Soxhlet extractor, 10 g of commercially available bulk anhydrous MgCl ₂ was dissolved by extraction under reflux with 250 ml of dehydrated and deoxygenated THF under an argon gas atmosphere. After about 20 hours, almost no MgCl ₂ solids are visible. Concentrate the extract to approximately 100ml. This is allowed to cool to room temperature and then dried under a stream of dry nitrogen gas to reach a constant weight (solid). The analytical values were as follows.

[Table] The powder X-ray diffraction pattern of the obtained solid is shown in FIG. It is clearly different from the diffraction diagram of MgCl ₂ (Figure 2), and a new peak based on the MgCl ₂ 1.5THF complex can be seen. Reference Example 1 (a) Co-precipitation with TiCl ₄ Example 1 was placed in a 200ml four-necked flask with a stirrer, immersed in a constant temperature bath at 25°C under an argon gas atmosphere.
MgCl ₂・1.5THF 8.4 mmol (1.84
g) was collected, 20 ml of THF was supplied, and the mixture was stirred at room temperature to obtain a colorless and transparent solution. When a solution of TiCl ₄ 2THF in tetrahydrofuran is gradually added dropwise to this solution, a pale yellow precipitate is formed. After continuing to stir for 1 hour, the precipitate was filtered off, thoroughly washed with purified n-hexane, and then dried under reduced pressure at room temperature. The elemental analysis values (weight %) and the formula of the powder obtained there are shown below.

[Table] In addition, when powder X-ray diffraction was measured on the obtained powder, the obtained X-ray diffraction image showed that the raw materials TiCl _4.2THF (described later) and MgCl ₂ .
The X-ray diffraction image was completely different from that of 1.5THF. This means that the complex obtained here is
It can be seen that it is not a mixture of TiCl _4.2THF and MgCl _2.1.5THF . Note that a tetrahydrofuran solution of TiCl ₄ 2THF was prepared as follows. TiCl ₄・2THF ^* 7.0 mmol (2.26 g) in a 100 ml four-necked flask with a stirrer under an argon gas atmosphere.
Collected, 45 ml of THF was dehumidified and dissolved oxygen gas was removed, and the mixture was stirred at room temperature.
A clear yellow solution was obtained. *Synthesis of TiCl ₄・2THF is published in the Journal of
Inorganic & Nuclear Chemistry
(Pergamon Press Ltd, Vol 24, 1105~
1109 (1962) of the United Kingdom). (B) Polymerization After replacing an autoclave with a stirrer with a capacity of 1 sufficiently with nitrogen gas, 25 mg of the powder obtained in (B) and 0.45 mmol of Al _i -Bu ₃ [Al(iso-C ₄ H ₉ ) ₃ ] were added.
(i.e. Al/Ti=15/1 (mol/mol))] and 500 ml of purified n-hexane.90
After heating to ℃, ethylene 5Kg/cm ² and hydrogen 4
Polymerize ethylene at Kg/cm ² and after 1 hour
119.5g of polyethylene powder was obtained. The polymerization activity and properties of the polymer were as follows. K = 960 (g polyethylene / g Ti catalyst component / ethylene partial pressure Kg / cm ² / hour hr) K _Ti = 16400 (g polymer / g Ti / ethylene partial pressure
Kg/cm ²・hour hr) Bulk density = 0.35 g/cc MI = 4.3 M _W /M _N = 2.9 Reference example 2 In the co-precipitation with TiCl ₄ in Reference example 1, twice the amount of MgCl ₂・1.5THF ( 16.8 mmol) and double the amount of THF (40 ml) in THF of MgCl ₂ 1.5 THF
solution, and add TiCl ₄ .
By dropping a solution of 2THF, a yellow complex with the following composition (% by weight) and the following formula was obtained:

[Table] In addition, when powder X-ray diffraction was measured on the obtained complex, the obtained X-ray diffraction image showed that the raw material
The X-ray diffraction images were completely different from those of TiCl _4.2THF and MgCl _2.1.5THF . From this, the complex obtained here is composed of _TiCl4.2THF and _MgCl2 .
It can be seen that it is not a mixture with 1.5THF. Using this complex, ethylene polymerization was carried out under the same conditions as in Reference Example 1 to obtain 80 g of polyethylene powder. The polymerization results are as follows. K = 640 K _Ti = 18800 Bulk density = 0.33 g/cc MI = 4.8 M _W /M _N = 2.8 Reference example 3 Powdered anhydrous magnesium chloride 4.40 g (46.20 m
mol) and 210 ml of tetrahydrofuran at room temperature to prepare a transparent homogeneous solution. 3.59 g (18.9 mmol) of titanium tetrachloride was added to the obtained tetrahydrofuran solution of the magnesium chloride/tetrahydrofuran complex, and the temperature was raised to 70° C. and then allowed to cool. After the temperature reached room temperature, 825 ml of n-hexane was added, and a yellow precipitate was obtained. After washing the precipitate with normal hexane, it was dried under reduced pressure.
The yield of the solid obtained was 14.3 g. Elemental analysis showed Mg7.65wt%, Ti3.14wt
%, Cl 30.0wt%, and others (C, H, and O of tetrahydrofuran) 59.2wt%. _MgCl2 and
It turned out to be a complex in which TiCl ₄ was co-precipitated. Slurry polymerization of ethylene was carried out at a polymerization temperature of 80° C. using a butane solvent and a catalyst consisting of 50 mg of the above complex and 0.77 mmol of triethylaluminum. Total pressure 18Kg/cm ² , ethylene partial pressure 4.51Kg/cm ² ,
_H2 /ethylene was 64.1 mol%, and the polymerization time was 15 minutes. 98 g of the obtained polyethylene, polymerization activity K (g polyethylene/g Ti catalyst component, ethylene partial pressure Kg/
cm ² /polymerization time hr) was 1730.

[Brief explanation of the drawing]

Figure 1 shows the MgCl ₂ obtained in Example 1.
Powder X-ray diffraction diagram of 1.5THF complex, Figure 2 is MgCl ₂
The powder X-ray diffraction pattern of

Claims (1)

[Claims] 1 General formula MgCl ₂ pY, characterized by dissolving magnesium chloride in tetrahydrofuran
A method for producing a tetrahydrofuran solution of a magnesium chloride/tetrahydrofuran complex for co-precipitation, represented by (Y is tetrahydrofuran, 1p2).