JPS638124B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for polymerizing olefins, and more particularly to a method for efficiently polymerizing olefins using a specific catalyst. Conventionally, in the polymerization method of olefins such as ethylene, a compound containing magnesium, such as magnesium halide, magnesium alkoxide, etc., is used as a catalyst carrier, and a substance obtained by reacting the substance with titanium halide has a high activity. It is known to be a component of catalysts (Special Publication No. 1973-
Publication No. 34098, Japanese Patent Application Laid-Open No. 1982-98076, Japanese Patent Application Publication No. 1983
-2580). However, in the above-mentioned conventional method, the catalyst activity and the quality of the obtained polyolefin were not satisfactory. In the highly active polymerization of olefins such as ethylene as described above, by increasing the activity, the catalyst removal step can be omitted, simplifying the manufacturing process, and by increasing the productivity per carrier, the use of a carrier can be improved. It is preferable to reduce the amount. Furthermore, in the production of polyolefin, it is desired that the bulk specific gravity of the resulting polymer be as high as possible from the viewpoint of slurry handling, that the particle size of the powder be uniform, and that the number of fine particles be small. From this point of view, the present inventors have conducted intensive research on a method for polymerizing olefins using a catalyst containing a reaction product of magnesium alkoxide and titanium halide. the result,
The present invention was completed by discovering that the polymerization of the target olefin can proceed efficiently by using a solid material obtained by treating magnesium alkoxide with multiple halides as a component of the catalyst. I came to the conclusion. That is, the present invention provides a method for polymerizing olefins using a catalyst formed by combining (A) a titanium-containing solid catalyst component and (B) an organoaluminum compound, in which (A) the titanium-containing solid catalyst component has the general formula Mg ( OR ¹ ) _p X ¹ _2-p (wherein, X ¹ is a halogen atom,
R ¹ represents a linear or side-chain alkyl group, alkenyl group, aryl group, cycloalkyl group, arylalkyl group or alkylaryl group having 1 to 20 carbon atoms; p represents 1 or 2; ) with the general formula X ² _o Ti(OR ² ) _4-o (wherein, X ² is a halogen atom,
^R2 represents an alkyl group or an aryl group having 1 to 10 carbon atoms, and n represents 1 to 4. ) is reacted with a halogen-containing titanium compound represented by the formula X ³ _n Si (OR ³ ) _4-n (in the formula,
X ³ is a halogen atom, R ³ is an alkyl group or aryl group having 1 to 10 carbon atoms, and m is 1 to 4. The present invention provides a method for polymerizing olefins, which is characterized in that it uses a solid material obtained by treatment with a halogen-containing silicon compound represented by (1), or a solid material obtained by further treating this solid material with titanium tetrachloride. The magnesium alkoxide used in the present invention has the general formula Mg(OR ¹ )X ¹ _2-p (wherein, X ¹ is a halogen atom,
R ¹ represents a linear or side-chain alkyl group, alkenyl group, aryl group, cycloalkyl group, arylalkyl group or alkylaryl group having 1 to 20 carbon atoms; p represents 1 or 2; ) is a compound represented by Here R ¹ is carbon number 1
~20, preferably 1 to 8 linear or side chain alkyl groups, alkenyl groups, aryl groups,
Indicates a cycloalkyl group, an arylalkyl group, an alkylaryl group, etc. Specifically, magnesium dimethoxide, magnesium diethoxide, magnesium dipropoxide, magnesium dibutoxide, magnesium dicyclohexoxide, magnesium dibenzoxide, and the like are preferred. Furthermore, the magnesium alkoxide of the present invention includes:
In addition to the above, monoalkoxides containing halogen (XMgOR ¹ ) can also be used. Note that these magnesium alkoxides can be easily obtained by known methods. On the other hand, the halogenated titanium compound used in the present invention has the general formula X ² nTi(OR ² ) _4-o (X ² is a halogen atom,
^R2 represents an alkyl group or an aryl group having 1 to 10 carbon atoms, and n represents 1 to 4. ), specifically TiCl ₄ , TiBr ₄ , CH ₃ OTiCl ₃ ,
C ₂ H ₅ OTiCl ₃ , C ₃ H ₇ OTiCl ₃ , (C ₂ H ₅ O) ₂ TiCl ₂
Examples include (C ₂ H ₅ O) ₃ TiCl. Furthermore ^{, the} _halogen - ^containing silicon compound used in the present invention usually has the general formula _: 4), specifically SiCl ₄ , CH ₃ OSiCl ₃ ,
_{( CH3O} ) _2SiCl2 , _{( CH3O} ) _3SiCl , _{C2H5OSiCl3 ,}
(C ₂ H ₅ O) ₂ SiCl ₂ , (C ₂ H ₅ O) ₃ SiCl, C ₃ H ₇ OSiCl ₃ ,
(C ₃ H ₇ O) ₂ SiCl ₂ , (C ₃ H ₇ O) ₃ SiCl, C ₆ H ₅ OSiCl ₃ ,
Examples include (C ₆ H ₅ O) ₂ SiCl ₂ and (C ₆ H ₅ O) ₃ SiCl. In the method of the present invention, first, the above-mentioned magnesium alkoxide and a halogen-containing titanium compound are reacted. This reaction may be carried out in an inert solvent such as pentane, hexane, heptane, cyclohexane, benzene, xylene, etc., or may be carried out without a solvent. The reaction temperature is 0~
200℃, preferably 20-150℃, reaction time 5
~10 hours, preferably 30 minutes to 5 hours. In addition, the ratio of the above magnesium alkoxide and halogen-containing titanium compound is usually such that the halogen-containing titanium compound is added to the magnesium alkoxide.
0.1-10 (molar ratio), preferably 0.5-5 (molar ratio)
shall be. In addition, when carrying out the above-mentioned reaction in the absence of a solvent, it is desirable to proceed with the reaction while placing both the above-mentioned compounds in a ball mill or the like and pulverizing them. In the present invention, after the above-mentioned reaction, the obtained product is sufficiently washed and then further treated with the halogen-containing silicon compound. The conditions at this time are not particularly limited and can be selected as appropriate.
Usually in the same inert solvent as mentioned above, reaction temperature 0-200°C, preferably 20-100°C, reaction time 5.
The time period is from minutes to 5 hours, preferably from 30 minutes to 4 hours. The ratio of the halogen-containing silicon compound to the magnesium alkoxide is usually 0.1 to 10 (molar ratio), preferably 0.5 to 5 (molar ratio). Note that the above treatment can be carried out without a solvent, but in this case, it is desirable to proceed with the reaction while pulverizing with a ball mill or the like. In the method of the present invention, the solid material obtained by the above treatment is thoroughly washed and used as a component of the catalyst. In another embodiment of the invention, the solid material obtained by the above treatment is further treated with titanium tetrachloride. In this case, the processing conditions are as follows:
200℃, preferably 20~150℃, time 5 minutes~5
The time should preferably be between 30 minutes and 4 hours.
Further, this treatment may be carried out in the above-mentioned inert solvent, or may be carried out without a solvent while being pulverized using a ball mill or the like. The proportion of titanium tetrachloride to be added is not particularly limited, but it is preferably about 1 to 20 times (molar ratio) to that of magnesium alkoxide. In the present invention, the solid material obtained by such treatment can also be used as a component of the catalyst. In the method of the present invention, the solid material obtained by the above treatment is used as (A) a titanium-containing catalyst component,
An organoaluminum compound is added as component (B) to this, and a catalyst consisting of both components (A) and (B) is used.
When polymerizing olefin, (A) is added to the reaction system.
A dispersion of the titanium-containing solid catalyst component described above as a component and an organoaluminum compound as a component (B) are added as a catalyst, and then an olefin 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. Taking the case of solution polymerization or suspension polymerization as an example, the amount of the catalyst component added is 0.001 to 10 mmol/, preferably 0.003 to 1 mmol/in terms of titanium atoms of the titanium-containing solid catalyst component,
On the other hand, the organoaluminum compound is adjusted to have an aluminum atom/titanium atom ratio of 1 to 1000 (atomic ratio), preferably 10 to 200 (atomic ratio), relative to the titanium-containing solid catalyst component. In addition, the olefin pressure in the reaction system varies depending on the type, but is usually 2 to 50
The atmospheric pressure is in the range of 0 to 200°C, preferably 50 to 150°C, and the reaction time is 10 minutes to 5 hours.
Preferably it is 30 minutes to 3 hours. Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen. Typical examples of organoaluminum compounds that are component (B) mentioned above include trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisopropylaluminium, triisobutylaluminum, and trioctylaluminum, and diethylaluminum monochloride and diisopropylaluminum monochloride. Examples include dialkylaluminum monohalides such as chloride, diisobutylaluminum monochloride, and dioctylaluminum monochloride. Polyolefins that can be polymerized using the above catalyst include homopolymers of α-olefins such as ethylene, propylene, 1-butene, and 1-hexene, as well as other α-olefins containing these olefins and small amounts of other α-olefins.
Examples include copolymers with olefins. In addition, when polymerizing propylene, adding an ester such as methyl p-toluate or ethyl benzoate to the above-mentioned reaction system improves the isotacticity of the resulting polypropylene. As mentioned above, if the titanium-containing solid catalyst component obtained by the method of the present invention is used as a catalyst component to polymerize olefins, the catalyst activity is extremely high, so that a sufficient effect can be obtained even with a small amount of use. is obtained. As a result, the deashing step (catalyst removal step) can be omitted. Furthermore, the amount of carrier used and the number of catalyst preparations per production amount of polyolefin can be significantly reduced compared to conventional methods. Furthermore, the resulting polyolefins such as polyethylene and polypropylene have a high bulk specific gravity and a good particle size distribution, making the powder very easy to handle. Next, the method of the present invention will be explained in more detail with reference to Examples. Example 1 [Production of solid catalyst component] 150 ml of dehydrated hexane, Mg was placed in a 500 ml four-necked flask equipped with a dropping funnel, a gas inlet, a stirring rod, and a reflux condenser.
Add 10.0g (88 mmol) of (OC ₂ H ₅ ) ₂ and heat at 20℃.
16.6 g (88 mmol) of TiCl ₄ was added dropwise. After the dropwise addition was completed, the temperature was raised to 70°C and reaction was carried out for 3 hours.
After the reaction, the temperature was returned to room temperature, the supernatant was removed, and 250 ml of hexane was added for washing. This operation was repeated five times to obtain solid substance P-1.
The amount of titanium supported on P-1 was 108 mg-Ti/g-support. Next, add the hexane slurry of P-1 at room temperature.
29.9 g (176 mmol) of SiCl ₄ was added dropwise. After the dropwise addition was completed, the temperature was raised to 70°C and the reaction was carried out for 3 hours. After the reaction, the temperature was lowered to room temperature, the supernatant liquid was taken out, 250 ml of hexane was added, and the mixture was washed by a decanting method. This operation was repeated five times to obtain solid catalyst component P-2. The amount of titanium supported in P-2 was 55 mg-Ti/g-support. Next, add the hexane slurry of P-2 at room temperature.
41.6 g (220 mmol) of TiCl ₄ was added dropwise. After the dropwise addition was completed, the temperature was raised to 70°C and reaction was carried out for 3 hours. After the reaction, return to room temperature and remove the supernatant.
Another 250 ml of hexane was added and the mixture was washed by the decanting method. Repeat this operation 5 times, solid catalyst component P
- got 3. The amount of titanium supported on P-3 is 303 mg.
It was Ti/g-support. [Polymerization of ethylene] 400 ml of hexane, 2 mmol of triethylaluminum, and 0.01 mmol of solid catalyst component P-2 as Ti were added to the autoclave No. 1, and the temperature was heated to 80°C. Hydrogen was added at 3 kg/cm ² and ethylene at 5 kg/cm ² , and polymerization was carried out for 1 hour while maintaining the ethylene at a total pressure of 9.3 kg/cm ² . As a result, 98.4 g of white polyethylene was obtained. The catalyst activity of the product obtained was 205 kg per hour per gram of titanium atom, the melt index was 1.5 g/10 minutes, the bulk specific gravity of the polymer was 0.26, and the content of fine powder of 105 μm or less was 3.0%. Examples 2 to 4 In Example 1, solid catalyst components (P-2) were produced by varying the amount of SiCl ₄ used, and ethylene was polymerized using these as catalysts. The results are shown in the table below.

[Production of solid catalyst component]

In Example 1, SiCl ₄ was replaced with Si
Solid catalyst component P-2 was produced in the same manner as in Example 1 except that 73.6 g (352 mmol) of (OC ₂ H ₅ ) ₂ Cl ₂ was used. The amount of titanium supported in P-2 was 72 mg-Ti/g-support. [Polymerization of ethylene] Polymerization of ethylene was carried out under the same conditions as in Example 1 except that the solid catalyst component P-2 was used. As a result, 75g of polyethylene was obtained,
The catalyst activity was 1 g of titanium atom, and the polyethylene yield was 156 kg per hour. The melt index of the obtained polyethylene was 1.7, the bulk specific gravity was 0.24, and the content of fine powder less than 105μ was 5.5% by weight. Example 6 [Production of solid catalyst component] A solution of ethylmagnesium chloride (C ₂ H ₅ MgCl) in tetrahydrofuran is reacted with ethanol in an equimolar amount of magnesium, and dried under reduced pressure to produce Mg
Prepare 10 g (95.7 mmol) of (OC ₂ H ₅ )Cl, suspend it in 150 ml of hexane, and add it to this suspension.
18.1 g (95.7 mmol) of TiCl ₄ was added dropwise, and after the addition, the reaction was carried out at 70° C. for 3 hours. Then further
36.4 g (191 mmol) of SiCl ₄ was added dropwise at 20°C, and 70
The temperature was raised to 0.degree. C., and the mixture was reacted for 3 hours. After the reaction, the temperature was lowered and the supernatant liquid was taken out at room temperature, 250 ml of hexane was added, and the mixture was washed by a decanting method. This operation was repeated five times to obtain solid catalyst component P-2. The amount of titanium supported in this P-2 is 35mg-Ti/g
-It was a carrier. [Polymerization of ethylene] Polymerization of ethylene was carried out under the same conditions as in Example 1, except that the above-mentioned solid catalyst component P-2 was used. As a result, 82.3 g of polyethylene was obtained, the catalyst activity was 1 g of titanium atom, and the polyethylene yield per hour was 171 kg. The melt index of the obtained polyethylene was 1.1, the bulk specific gravity was 0.27, and the fine powder less than 105μ was 7.3% by weight.
It was hot. Example 7 [Polymerization of propylene] 400 ml of n-heptane in autoclave 1,
2 mmol of triethylaluminum, solid catalyst component P-2 obtained in Example 1 and 0.04 as Ti
mmol was added and the temperature was raised to 70°C. Propylene was continuously supplied to the reaction system to maintain a concentration of 7 kg/cm ² and polymerization was carried out for 2 hours. After completion, the temperature was lowered, unreacted gas was purged, and the polymer was recovered. The yield of polypropylene was 78 g, and the boiling n-heptane insoluble content was 55.3%. Comparative Example 1 Ethylene polymerization was carried out under the same conditions as in Example 1 except that 0.05 mmol of Ti was used in the solid substance P-1 obtained in Example 1. As a result, 63.1 g of polyethylene was obtained, the catalyst activity was 1 g of titanium atom, and the yield of polyethylene per hour was 26 kg. The melt index of the obtained polyethylene was 2.3, the bulk specific gravity was 0.19, and the amount of fine powder less than 105μ was 1.3% by weight. Example 8 The solid catalyst component P-3 obtained in Example 1 was
Ethylene polymerization was carried out under the same conditions as in Example 1, except that 0.01 mmol of ethylene was used. As a result, 132 g of polyethylene was obtained, and the catalyst activity was 1 g of titanium atom, polyethylene yield per hour.
It weighed 275Kg. The polyethylene obtained had a melt index of 1.2 and a bulk specific gravity of 0.32. Examples 9 to 11 Solid catalyst component P-2 obtained in Examples 2 to 4 was further treated with excess TiCl ₄ to obtain solid catalyst component P-
The following table shows the results of producing 3 and polymerizing ethylene using them as catalysts.

[Polymerization of propylene]

In Example 7, P-2 in Example 1 was replaced with P-2.
Polymerization of propylene was carried out under the same conditions as in Example 7 except that -3 was used as the solid catalyst component. 123g of polypropylene was obtained and boiled n-
The heptane insoluble content was 60.1%.

[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)

[Scope of Claims] 1. In a method for polymerizing olefins using a catalyst comprising a combination of (A) a titanium-containing solid catalyst component and (B) an organoaluminum compound, the titanium-containing solid catalyst component (A) has the general formula Mg( ^OR1 ) _p
X ¹ _2-p (In the formula, X ¹ is a halogen atom, R ¹ is a carbon number of 1
~20 straight-chain or side-chain alkyl groups, alkenyl groups, aryl groups, cycloalkyl groups, arylalkyl groups, or alkylaryl groups, and p represents 1 or 2. ), the general formula X ² _o Ti
(OR ² ) _4-o (wherein, X ² is a halogen atom, R ² is an alkyl group or aryl group having 1 to 10 carbon atoms, and n is 1 to 4). React at a ratio of 0.1 to 10 (molar ratio),
^{Then ,} _it is ^represented _by ^the general formula A method for polymerizing olefins, characterized by using a solid material obtained by treatment with a halogen-containing silicon compound. 2. In a method for polymerizing olefins using a catalyst comprising a combination of (A) a titanium-containing solid catalyst component and (B) an organoaluminum compound, the general formula Mg(OR ¹ ) _p is used as the titanium-containing solid catalyst component (A).
X ¹ _2-p (In the formula, X ¹ is a halogen atom, R ¹ is a carbon number of 1
~20 straight-chain or side-chain alkyl groups, alkenyl groups, aryl groups, cycloalkyl groups, arylalkyl groups, or alkylaryl groups, and p represents 1 or 2. ), the general formula X ² _o Ti
(OR ² ) _4-o (wherein, X ² is a halogen atom, R ² is an alkyl group or aryl group having 1 to 10 carbon atoms, and n is 1 to 4). React at a ratio of 0.1 to 10 (molar ratio),
^{Then ,} _it is ^represented _by ^the general formula 1. A method for polymerizing olefins, which comprises using a solid material obtained by treating with a halogen-containing silicon compound and further treating with titanium tetrachloride.