JPS64964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing α-olefin, and more particularly to a method for polymerizing α-olefin with high activity using a catalyst comprising a specific activated titanium catalyst component and an organoaluminum compound.

Conventionally, methods for polymerizing olefins using a catalyst consisting of a solid catalyst component containing magnesium, titanium, and halogen and an organometallic compound have been known. There is a method disclosed in Japanese Patent No. 56-30681.

However, these methods have disadvantages such as insufficient activity per unit weight of the catalyst, and the particle size distribution of the produced polymer is wide over a wide range and contains fine powder, which is undesirable.

Therefore, the inventors of the present invention have conducted extensive research in order to improve the drawbacks of the above-mentioned conventional techniques. As a result, a solid component produced by adding a precipitation agent mainly composed of Lewis acid to a homogeneous solution obtained by mixing and reacting a specific magnesium compound, titanium compound, and alcohol can be used as a component of the catalyst. We found that the purpose could be achieved by The present invention was completed based on this knowledge. That is, the present invention provides (A) general formula Mg(OR ¹ ) ₂ [wherein R ¹ is carbon number 1]
~5 alkyl group is shown. ], an alkoxymagnesium compound represented by the general formula TiX ¹ ₄ [wherein,
X ¹ represents a halogen atom. ] and a halogen-containing titanium compound represented by the general formula R ² OH [wherein,
R ² represents an alkyl group having 4 to 20 carbon atoms. ] is reacted under heating to form a homogeneous solution, and then the solution is mixed with the general formula TiX ² ₄ [wherein, X ² represents a halogen atom]. ] or the general formula AlR ³ ₂ X ³ [wherein,
R ³ represents an alkyl group having 1 to 5 carbon atoms, and X ³ represents a halogen atom. ] and (B) a solid component produced by adding a precipitating agent represented by the general formula AlR ⁴ ₃ [wherein R ⁴ represents an alkyl group having 1 to 5 carbon atoms]. 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 alkoxymagnesium compound used in the present invention is represented by the general formula Mg(OR ¹ ) ₂ ,
Here, R ¹ represents an alkyl group having 1 to 5 carbon atoms as described above. Preferred examples of the alkoxymagnesium compounds include magnesium diethoxide, magnesium diethoxide, magnesium dipropoxide, and magnesium dibutoxide.

Further, the halogen-containing titanium compound used in the present invention is represented by _{the general formula TiX 14} ^, where X ¹ represents a halogen atom. Specifically, such halogen-containing titanium compounds include TiCl ₄ ,
Examples include TiBr ₄ .

Furthermore, the alcohol used in the present invention has the general formula
It is represented by R ² OH, where R ² represents an alkyl group having 4 to 20 carbon atoms. Specific examples of this alcohol include butanol, isobutanol, amyl alcohol, octanol, and the like.

In the present invention, first, the above-mentioned alkoxymagnesium compound, halogen-containing titanium compound, and alcohol are reacted under heating to prepare a homogeneous solution. Here, the blending ratio of the three above is not particularly limited and may be determined as appropriate, but usually the total amount of the halogen-containing titanium compound and alcohol is 1 to 10 mol, preferably 2 mol, per 1 mol of the alkoxymagnesium compound. ~5 moles. Also, 0.05 halogen-containing titanium compounds per mole of alcohol.
~0.5 mol, preferably 0.1-0.3 mol. The reaction between these three is carried out under heating in an inert hydrocarbon solvent such as pentane, hexane, heptane, octane, etc. or without a solvent. The heating temperature can be selected as appropriate depending on the conditions, but it is usually room temperature to 200℃,
Preferably it should be between 40 and 150°C. The reaction time should be between 5 minutes and 10 hours, preferably between 30 minutes and 5 hours.

In the method of the present invention, a homogeneous solution is produced by the above-mentioned reaction, and then a precipitation agent consisting of a Lewis acid is added to the homogeneous solution obtained. Here, as the Lewis acid, a tetrahalogenated titanium compound represented by the general formula TiX ² ₄ or a dialkyl aluminum monohalide represented by the general formula AlR ³ ₂ X ³ is used. Here, R ³ represents an alkyl group having 1 to 5 carbon atoms, and X ² and X ³ represent halogen atoms such as chlorine, bromine, and iodine. A specific example of the tetrahalogenated titanium compound represented by the general formula TiX ² ₄ is titanium tetrachloride. Examples of the dialkylaluminum monohalide represented by ^the general formula AlR ³ ₂

The amount of the precipitation agent made of the Lewis acid to be added may be determined as appropriate depending on the conditions, etc., but usually the total amount of the halogen-containing titanium compound and the precipitation agent is 1 to 50 mol, preferably 1 to 50 mol, per 1 mol of the alcohol. is 1.5
It should be ~10 mol.

The reaction of adding a precipitating agent to the above-mentioned homogeneous solution is usually carried out at 0 to 200°C, preferably 20 to 150°C for 5 minutes to
It may be carried out for 10 hours, preferably 30 minutes to 5 hours.

After the reaction is complete, the resulting solid component is thoroughly washed with an inert solvent such as n-heptane, and then
It is used as the component (A) (solid catalyst component) of the α-olefin polymerization catalyst of ~8.

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.

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

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 300°C, preferably 50 to 300°C.
The temperature shall be 200℃. 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.

In the method of the present invention, an organoaluminum compound (trialkyl aluminum) represented by the general formula AlR ⁴ ₃ is used as the component (B) of the catalyst. here
R ⁴ is an alkyl group having 1 to 5 carbon atoms, and specific examples of such compounds include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, and mixtures thereof 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 usually have the general formula R ⁵ −CH=
α-olefins represented by CH ₂ (in the formula, R ⁵ represents hydrogen or an alkyl group having 1 to 6 carbon atoms);
For example, linear monoolefins such as ethylene, propylene, butene-1, hexene-1, octene-1, etc., branched monoolefins such as 4-methyl-pentene-1, dienes such as butadiene, and various others. The present invention can be effectively utilized for homopolymerization of these or copolymerization of various α-olefins.

According to the method of the present invention, the activity of the catalyst used is extremely high and the bulk density of the obtained polymer is high, so that products with extremely high product value can be obtained. In addition, in the catalyst consisting of both components (A) and (B) mentioned above, amines, amides, ketones, nitriles, phosphines, phosphoformamides, esters, thioethers, thioesters, acid anhydrides, etc. When propylene is polymerized using electron-donating compounds such as acid halides, aldehydes, and organic acids, the stereoregularity index (II) increases.
Polypropylene with excellent properties 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 index (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 Drying in a 500 ml glass flask 150ml hexane,
Magnesium diethoxide 10.0g (88 mmol)
4.2 g (22 mmol) of titanium tetrachloride and 2.0 g (33 mmol) of isopropyl alcohol were added, the temperature was raised, and the reaction was carried out under reflux for 1 hour. The reaction system here was in a slurry state. Next, 22.9 g (176 mmol) of 2-ethylhexanol was added to this system and reacted under reflux for 2 hours to dissolve the solid and obtain a homogeneous solution. Next, 83.2 g (440 mmol) of titanium tetrachloride was added dropwise to this, and a solid precipitated out. After the dropwise addition was completed, the reaction was carried out under reflux for 3 hours. After the reaction was completed, it was filtered at 40°C and the solid components were thoroughly washed with n-hexane. When the amount of Ti supported on the obtained solid component was determined by a colorimetric method, it was found to be 49 mg-Ti/g-support.

(2) Polymerization of ethylene Add 400 ml of dry hexane to the autoclave from step 1.
2.0 mmol of triisobutylaluminum (TIBA) and 0.01 mmol of the above solid catalyst component as Ti were added, and the temperature was raised to 80°C. Next, hydrogen was added at 3 kg/
cm ² , and 5 kg/cm ² of ethylene was added. Furthermore, the total pressure
Polymerization was carried out for 1 hour while continuously supplying ethylene to maintain the pressure at 9.3 kg/cm ² . As a result, 138 g of polyethylene was obtained. The catalytic activity was 288 kg per hour for 1 g of Ti. Polymer melt index (MI, 190℃, 2160g load) is 1.3g/10
minutes, and the bulk density was 0.30 g/ml.

(3) Polymerization of propylene N-heptane dried in the autoclave from step 1
400ml, triethyl aluminum 2.0 mmol, p
-0.6 mmol of methyl toluate and 0.02 mmol of the above solid catalyst component as Ti were added, and the temperature was raised to 70°C. Then, 0.2Kg/ ^cm2 of hydrogen was added and the mixture was heated at 70℃ for 2 hours while maintaining the total pressure at 7.0Kg/ ^cm2 with propylene.
Polymerized for hours. As a result, 162g of polypropylene
was gotten. The II of this polymer is 80.6%,
The bulk density was 0.33 g/ml. Additionally, 17.0 g of soluble polymer was recovered from the polymerization solvent.

Example 2 (1) Production of solid catalyst component 150 ml of dry hexane was added to a 500 ml glass flask.
Magnesium diethoxide 10g (88 mmol),
Titanium tetrachloride (16.6 g (88 mmol) and 2-
45.8 g (352 mmol) of ethylhexanol was added and reacted at 60°C for 2 hours to obtain a homogeneous solution.
Next, this solution was heated to 40°C, and 112 g (880 mmol) of ethylaluminum dichloride was added dropwise thereto over about 1 hour. The temperature was further increased to 60℃ 1
After reacting for an hour, the mixture was allowed to stand, and solid components were separated by decanting and thoroughly washed with n-hexane. Thereafter, fresh n-hexane was added to the obtained solid component to obtain a catalyst slurry. The amount of Ti supported in this component was 98 mg-Ti/g-carrier.

(2) Polymerization of ethylene The above is used as a solid catalyst component and Ti is 0.01
Ethylene polymerization was carried out under exactly the same conditions as in Example 1 except that millimole was used. As a result, 120 g of polyethylene was obtained. Catalytic activity is Ti1g, 1
It was 250Kg per hour. In addition, the bulk density of the obtained polymer was 0.29 g/ml, and the MI was 1.2 g/ml.
It was hot in 10 minutes.

Comparative Example 1 (1) Production of solid catalyst component The same treatment as in Example 1 was performed except that 2-ethylhexanol was not added. As a result, the reaction solution before dropping titanium tetrachloride was non-uniform. Further, the amount of Ti supported in the obtained solid component was 150 mg-Ti/g-support.

(2) Polymerization of ethylene The above is used as a solid catalyst component and Ti is 0.02
Ethylene polymerization was carried out under the same conditions as in Example 1, except that millimole was used. As a result, 96 g of polyethylene was obtained. In addition, the catalytic activity is Ti1g,
The resulting polymer had a bulk density of 0.18 g/ml and an MI of 1.8 g/10 min.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] 1 (A) General formula Mg(OR ¹ ) ₂ [In the formula, R ¹ is a carbon number of 1 to
5 shows the alkyl group. ], an alkoxymagnesium compound represented by the general formula TiX ¹ ₄ [wherein X ¹
indicates a halogen atom. ] and a halogen-containing titanium compound represented by the general formula R ² OH [wherein R ²
represents an alkyl group having 4 to 20 carbon atoms. ] is reacted under heating to form a homogeneous solution, and then the solution is mixed with the general formula TiX ² ₄ [wherein, X ² represents a halogen atom]. ] or the general formula AlR ³ ₂ X ³ [wherein,
R ³ represents an alkyl group having 1 to 5 carbon atoms, and X ³ represents a halogen atom. ] and (B) a solid component produced by adding a precipitating agent represented by the general formula AlR ⁴ ₃ [wherein R ⁴ 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.