JPS64963B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing α-olefin, and more specifically, a method for polymerizing α-olefin having 2 to 8 carbon atoms using a catalyst comprising a specific activated titanium catalyst component and an organoaluminum compound. , relates to a method for producing highly stereoregular polyolefins with high activity.

A method of stereoregularly polymerizing α-olefin using a catalyst consisting of a solid catalyst component containing magnesium, titanium, and a halogen and an organoaluminum compound has been known for some time.
There are methods disclosed in JP-A-98076 and JP-A-54-40293.

However, all of the above conventional methods have advantages and disadvantages, and each has drawbacks such as a low bulk density of the resulting polymer, poor particle size distribution, low stereoregularity, or insufficient polymerization activity. In particular, there is an inverse correlation between the polymerization activity of the catalyst and the stereoregularity of the produced polymer, and it has so far been extremely difficult to simultaneously maintain both of them.

The present inventors have conducted extensive research in order to overcome the drawbacks of the above-mentioned conventional techniques and to develop a method for producing polyolefins with high bulk density while maintaining a high degree of both polymerization activity and stereoregularity of the resulting polymer. .
As a result, the objective was achieved by reacting magnesium dialkoxide with a specific titanium compound and further reacting titanium tetrahalide in the presence of an organic acid ester compound and using the resulting product as a component of the catalyst. They have discovered that it is possible to do so, and have completed the present invention. That is, the present invention provides (A)
General formula TiX ¹ ₄ [wherein, X ¹ represents a halogen atom]. ]
Titanium tetrahalide represented by and the general formula
Mg(OR ¹ ) ₂ [In the formula, R ¹ represents an alkyl group having 1 to 5 carbon atoms. ] and then reacted with a magnesium dialkoxide represented by the general formula TiX ² ₄ [wherein X ² represents a halogen atom] to the obtained solid material. ] and (B) a solid component produced by reacting titanium tetrahalide and an organic acid ester compound represented by the general formula AlR ² ₃ [wherein R ² is a carbon number of 1
~5 alkyl group is shown. The present invention provides a method for polymerizing α-olefin, which comprises polymerizing α-olefin having 2 to 8 carbon atoms using a catalyst containing an organoaluminum compound represented by the following formula.

The magnesium dialkoxide used in the present invention is represented by the general formula Mg(OR ¹ ) ₂ as described above, where R ¹ represents an alkyl group having 1 to 5 carbon atoms. Preferred examples of magnesium dialkoxides include magnesium dimethoxide, magnesium diethoxide, magnesium dipropoxide, and magnesium dibutoxide. Moreover, although commercially available magnesium dialkoxides can be used, those produced by the reaction of metallic magnesium and alcohol may also be used.

In the present invention, the above magnesium dialkoxide is reacted with titanium tetrahalide represented by the general formula TiX ¹ ₄ . In the formula, X ¹ represents a halogen atom as described above. Examples of the titanium tetrahalide include titanium tetrachloride and titanium tetrabromide, with titanium tetrachloride being particularly preferred.
Note that, if necessary, tetraalkoxytitanium represented by the general formula Ti(OR ³ ) ₄ can be used together with this titanium tetrahalide, where R ³
represents an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and specifically includes tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, etc. be able to.

There are no particular restrictions on the conditions for the above reaction,
It may be determined as appropriate depending on various circumstances. Usually 0.5 mol or less, preferably 0.1 mol of titanium tetrahalide per 1 mol of magnesium dialkoxide.
~0.3 mol and also tetraalkoxytitanium 1
The amount is less than 1 mol, preferably 0.01 to 0.5 mol. The reaction temperature is 0 to 200°C, preferably 20 to 150°C, and the reaction is carried out for about 5 minutes to 10 hours, preferably 30 minutes to 5 hours. In this reaction system, pentane,
Inert hydrocarbons such as hexane, heptane, octane, etc. can also be added as solvents.

In the above reaction, titanium tetrahalide and tetraalkoxytitanium can be used together, but in this case, both may be reacted simultaneously with magnesium dialkoxide, or one of them may be reacted first and then the other. may be added to react. However, the method of first reacting titanium tetrahalide and tetraalkoxytitanium to form alkoxytitanium halide and then reacting this with magnesium dialkoxide is not preferred as it is not possible to obtain a catalyst that can achieve the object of the present invention. .

In the method of the present invention, after washing the solid material obtained by the above-mentioned reaction as necessary, this solid material is given the general formula TiX ² ₄ [wherein X ² represents a halogen atom]. ] Tetrahalogenated titanium and an organic acid ester compound are reacted.
Examples of the organic acid ester compounds used here include methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, Methyl methacrylate, ethyl crotonate, ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzoate benzyl acid, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate,
Ethyl anisate, ethyl ethoxybenzoate, p-
Ethyl butoxybenzoate, ethyl o-chlorobenzoate, ethyl naphthoate, γ-butyrolactone,
Examples include esters having 2 to 18 carbon atoms such as δ-valerolactone, coumarin, phthalide, and ethylene carbonate, but especially alkyl esters of aromatic carboxylic acids such as benzoic acid, p-methoxybenzoic acid, and p-ethoxybenzoic acid. C1-4 alkyl esters of aromatic carboxylic acids such as benzoic acid and toluic acid are preferred.

Further, the titanium tetrahalide which is reacted with the above-mentioned solid substance together with the above-mentioned organic acid ester compound is represented by the general formula TiX ² ₄ . Here, X ² represents a halogen atom as described above. Specific examples include TiCl ₄ , TiBr ₄ , TiI ₄ and the like. These may be used alone or as a mixture. Among these, it is particularly preferable to use titanium tetrachloride (TiCl ₄ ).

The conditions for reacting the above-mentioned solid substance with the organic acid ester compound and titanium tetrahalide are not particularly limited, but usually, for 1 mole of magnesium dialkoxide used to produce the solid substance,
1 mol or less of organic acid ester compound, preferably
The amount may be 0.1 to 0.5 mol, and titanium tetrahalide may be used in large excess. Furthermore, the reaction temperature is 0~
The temperature is 200°C, preferably 50 to 150°C, for 5 minutes to 10 hours, preferably 30 minutes to 5 hours. This reaction can also be carried out using an inert solvent such as pentane, hexane, heptane, etc., if necessary.

After the above-mentioned reaction is completed, the solid product is separated from the reaction solution, and the obtained product is thoroughly washed with an inert solvent such as heptane as necessary to obtain the desired solid component (solid catalyst component). ).

According to the method of the present invention, the above-mentioned solid component is the (A) component, and the organoaluminum compound is the (B) component.
Polymerization of α-olefin of ~8 is carried out.

In polymerizing α-olefins having 2 to 8 carbon atoms, a dispersion of the solid component as component (A) and an organoaluminum compound as component (B) are added to the reaction system, and then carbon is added to the reaction system. Numbers 2 to 8 of α-olefins are introduced.

The polymerization method and conditions are not particularly limited, and any of solution polymerization, suspension polymerization, gas phase polymerization, etc. is possible, and both continuous polymerization and discontinuous polymerization are possible. For example, in the case of solution polymerization or suspension polymerization, the amount of the catalyst component added is 0.001 to 1.0 mmol per titanium atom for component (A), and the amount of component (B) is 0.001 to 1.0 mmol per titanium atom. The amount is 1 to 1000 (molar ratio), preferably 5 to 500 (molar ratio) to titanium atoms. The olefin pressure in the reaction system is preferably normal pressure to 50 kg/ ^cm2 , and the reaction temperature is room temperature to 200°C, preferably 40 to 200°C.
The temperature shall be 150℃. Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen. The reaction time is 5 minutes to 10 hours, preferably 30 hours.
The time may be appropriately selected between minutes and 5 hours.

The organoaluminum compound which is the component (B) of the catalyst used in the method of the present invention is represented by the general formula AlR ² ₃ . Here R ² has 1 to 5 carbon atoms
represents an alkyl group. Specific examples include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, and the like. Moreover, a mixture of these can also be used.

In the method of the present invention, an α-olefin having 2 to 8 carbon atoms is polymerized using the catalyst as described above. Such α-olefins include α-olefins represented by the general formula R ⁴ -CH=CH ₂ (wherein R ⁴ represents hydrogen or an alkyl group having 1 to 6 carbon atoms), such as ethylene, propylene, butene, etc. -1,hexene-
1, straight-chain monoolefins such as octene-1, branched monoolefins such as 4-methyl-pentene-1, dienes such as butadiene, and various others. Alternatively, it can be effectively used for copolymerization of various α-olefins.

According to the method of the present invention, the activity of the catalyst used is extremely high, and the stereoregularity and bulk density of the resulting polymer are high, so that products with extremely high product value can be obtained. In addition, to the catalyst consisting of both components (A) and (B) mentioned above, amines, amides,
propylene by adding electron-donating compounds such as ketones, nitriles, phosphines, phosphoramides, esters, thioethers, thioesters, acid anhydrides, acid halides, aldehydes, and organic acids. When polymerization is carried out, polypropylene with a better stereoregularity coefficient (II) is obtained.

As described above, the method of the present invention is a highly active polymerization method that yields polymers with high product value, and this combined with the ability to omit the catalyst removal step makes it a very effective method. can.

Next, examples of the present invention will be shown. Note that all operations in the following examples were performed under an argon stream. Moreover, the stereoregularity coefficient (II) determined in the examples was defined as follows.

II = Boiling of polymer insoluble in solvent during polymerization Weight of n-heptane insoluble polymer / Weight of polymer insoluble in solvent during polymerization x 100 (%) Example 1 (1) Production of solid catalyst component 150 ml of purified n-heptane In a four-necked flask, add 10.0 g (88 mmol) of magnesium diethoxide, 4.16 g (22 mmol) of titanium tetrachloride, and 3.0 g of titanium tetrabutoxide (TBT).
(8.8 mmol) was added and reacted at 80°C for 1 hour.
Next, the temperature was lowered to room temperature, the supernatant liquid was removed, and n-heptane was added for washing. Do this operation twice,
150 ml of n-heptane was added to form a slurry. Next, 2.64 g (17.6 mmol) of ethyl benzoate was added, and the mixture was treated at 80° C. for 1 hour. Furthermore, titanium tetrachloride
166 g (880 mmol) was added and reacted at 100°C for 3 hours. Thereafter, the temperature was lowered to 80 DEG C., the solution was allowed to stand, and the supernatant liquid was drained, and 150 ml of n-heptane was newly added, stirred, allowed to stand, and the liquid was drained for washing. After carrying out this operation sufficiently, fresh n-heptane was added to obtain a solid catalyst component. When the amount of Ti supported on the obtained solid catalyst component was determined by colorimetric method, it was found to be 19 mg-Ti/g.
- It was a carrier.

(2) Polymerization of propylene 400 g of purified n-heptane in the autoclave of 1
ml, 2.0 mmol of triethylaluminum (TEA), 0.6 mmol of methyl p-toluate, and 0.02 mmol of the above solid catalyst component as Ti were added.
The temperature was raised to ℃. Next, 0.2 kg/cm ² of hydrogen was added, and polymerization was carried out at 70° C. for 2 hours while maintaining the total pressure at 7.5 kg/cm ² with propylene. After the reaction was completed, unreacted gas was removed and filtered to obtain 150 g of white polypropylene powder. The catalyst activity was 156 kg per hour per 1 g of Ti. The II of this polymer is 93.8
%, and the bulk density was 0.32 g/ml. Additionally, 5.3 g of soluble polymer was recovered by evaporating the liquid phase.

(3) Polymerization of ethylene Purified n-hexane 400 g in autoclave 1
ml, add 2.0 mmol of triethylaluminum and 0.01 mmol of the above solid catalyst component as Ti 80
The temperature was raised to ℃. Next, add 3.0Kg/cm ² of hydrogen,
Furthermore, polymerization was carried out for 1 hour while continuously supplying ethylene so as to maintain the total pressure at 9.3 Kg/cm ² . As a result, 127 g of white polyethylene was obtained. The catalyst activity was 265 kg per hour per 1 g of Ti. Polymer melt index (MI, 190℃, 2.16Kg
load) is 1.6g/10min, and the bulk density is 0.33
g/ml.

Example 2 (1) Production of solid catalyst component A solid catalyst component was produced under exactly the same conditions and operations as in Example 1(1) except that titanium tetrabutoxide was not added. The amount of Ti supported on the obtained solid catalyst component was determined by a colorimetric method, and it was found to be 26 mg-Ti/g-support.

(2) Polymerization of propylene Propylene was polymerized under the same conditions as in Example 1 (2) except that the solid catalyst component obtained in Example 2 (1) was used. As a result, 115 g of polypropylene was obtained. The bulk density of this polymer was as high as 0.38 g/ml, and II was 92.3%. Additionally, 6.8 g of soluble polymer was recovered.

Example 3 (1) Production of solid catalyst component In Example 1 (1), 2.08 g of titanium tetrachloride
(11 mmol), titanium tetrabutoxide
A solid catalyst component was produced under exactly the same conditions as in Example 1(1) except that 15) g (4.4 mmol) was used. When the amount of Ti supported on the obtained solid catalyst component was determined by a colorimetric method, it was found to be 20 mg-Ti/g-supported material.

(2) Polymerization of propylene Propylene was polymerized under the same conditions as in Example 1 (2) except that the solid catalyst component obtained in Example 3 (1) was used. As a result, 173 g of polypropylene was obtained. The bulk density of this polymer was as high as 0.40 g/ml, and II was as high as 94.2%. Additionally, 3.9g of soluble polymer was recovered.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the steps for preparing a catalyst used in the method of the present invention.

Claims (1)

[Claims] 1 (A) General formula TiX ¹ ₄ [In the formula, X ¹ represents a halogen atom. titanium tetrahalide represented by the general formula Mg(OR ¹ ) ₂ [wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms]. ] and then reacted with a magnesium dialkoxide represented by the general formula TiX ² ₄ [wherein X ² represents a halogen atom] to the obtained solid material. ] and (B) a solid component produced by reacting titanium tetrahalide and an organic acid ester compound represented by the general formula AlR ² ₃ [wherein R ² represents an alkyl group having 1 to 5 carbon atoms]. A method for polymerizing an α-olefin, which comprises polymerizing an α-olefin having 2 to 8 carbon atoms using a catalyst containing an organoaluminum compound represented by the following formula.