JPH0240088B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for polymerizing α-olefin, and more specifically, the present invention relates to a method for polymerizing α-olefin, in which α-olefin is polymerized using a catalyst consisting of a specific activated titanium catalyst component and an organometallic compound to form a highly stereoregular polyα-olefin. Concerning the method of obtaining activity. Conventionally, α-
Methods for polymerizing olefins stereoregularly are known, for example, Japanese Patent Publication No. 46-34098;
42137, JP 52-98076, JP 52-147688, JP 53-2580, JP 53-109587, JP 56-
5403, JP-A-57-63308, and JP-A-57-63309. However, since the catalyst used in the above method is manufactured through an extremely complicated process, the properties of the catalyst are not constant, and as a result, the reproducibility of the physical properties of the resulting polymer is insufficient. In particular, the degree and reproducibility of stereoregularity in polypropylene, polybutene, etc. are insufficient, and improvement thereof is desired. An object of the present invention is to provide a method for stably preparing a polymerization catalyst in a short time and in a simple process, and producing a polymer with excellent stereoregularity with good reproducibility and high activity. be. That is, the present invention provides a method for polymerizing α-olefin using (A) a solid catalyst component containing a magnesium compound and a titanium compound and (B) a catalyst containing an organometallic compound, in which the general formula Mg (OR ¹ ) is used. ₂
[In the formula, R ¹ represents an alkyl group, a cycloalkyl group, or an aralkyl group having 1 to 20 carbon atoms. ] is treated with an aliphatic alcohol, and then in the presence of an aromatic acid ester, the general formula Ti(OR ² ) _o X ¹ _4-o [wherein R ² is a carbon number of 1
~10 alkyl, cycloalkyl, aryl or aralkyl groups, and ^X1 represents a halogen atom. Further, n is a real number satisfying 0≦n<4. A solid product obtained by reacting with a halogen-containing titanium compound represented by ] is used as the (A) component of the above catalyst, and an organoaluminum compound is used as the (B) component of the above catalyst. This is a method for polymerizing α-olefin. The magnesium dialkoxide used in the present invention is represented by the general formula Mg(OR ¹ ) ₂ ,
Here, R ¹ represents an alkyl group, cycloalkyl group, or aralkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, as described above. Preferred examples of these magnesium dialkoxides include magnesium dimethoxide, magnesium diethoxide, magnesium dipropoxide, magnesium dibutoxide, and magnesium dicyclohexoxide. 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 treated with an aliphatic alcohol, and specific examples of this alcohol include methanol, ethanol,
propanol, isopropanol, butanol,
Examples include isobutanol, amyl alcohol, octanol, 2-ethylhexanol, allyl alcohol, crotyl alcohol, propargyl alcohol, and the like. The amount of the aliphatic alcohol used in this aliphatic alcohol treatment is not particularly limited and may be appropriately selected depending on various conditions, but usually 0.01 to 100% of the aliphatic alcohol is used per mole of the magnesium dialkoxide. 2 mol, preferably 0.02
It should be ~1 mol. Further, the temperature and time of this aliphatic alcohol treatment may be determined as appropriate, but generally the treatment time is 0.1 to 5 hours at 0 to 150°C, preferably 0.5 to 2 hours at 20 to 100°C. Note that in the aliphatic alcohol treatment, a solvent such as pentane, hexane, heptane, etc. can also be used. Further, in the present invention, after the aliphatic alcohol treatment, it is necessary to wash the product if necessary and to react the obtained product with a halogen-containing titanium compound in the presence of an aromatic acid ester. Examples of aromatic acid esters used here include methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate,
Methyl anisate, ethyl anisate, ethyl ethoxybenzoate, ethyl p-butoxybenzoate, o-
Examples include ethyl chlorobenzoate, ethyl naphthoate, coumarin, and phthalide. Among these, aromatic acids such as benzoic acid, p-methoxybenzoic acid, p-ethoxybenzoic acid, and toluic acid have a carbon number of 1.
-4 alkyl esters are preferred. In addition, halogen-containing titanium compounds have the general formula Ti
It is a halogen-containing tetravalent titanium compound represented by (OR ² ) _o X ¹ _4-o . Here, R ² is an alkyl group, cycloalkyl group, aryl group or aralkyl group having 1 to 10 carbon atoms, n is a real number of 0 or more and less than 4, and X ¹ represents a halogen atom. Specifically, titanium tetrahalides such as TiCl ₄ , TiBr ₄ , TiI ₄ , Ti(OCH ₃ )Cl ₃ , Ti
( _OC2H5 ) _Cl3 ,Ti ₍ On- _C4H9 ) _Cl3 ,Ti _{( OC2H5 )}
Trihalogenated alkoxytitanium, such as _Br3 , Ti
(OCH ₃ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Br ₂ , Ti (On−
Dihalogenated alkoxytitanium such as C ₄ H ₉ ) ₂ Cl ₂ , Ti(OC ₂ H ₅ ) ₂ Br ₂ , Ti(OCH ₃ ) ₃ Cl, Ti
(OC ₂ H ₅ ) ₈ Cl, Ti (On−C ₄ H ₉ ) ₈ Cl, Ti
Examples include monohalogenated trialkoxytitanium such as (OC ₂ H ₅ ) ₃ Br. These may be used alone or as a mixture. Among these, it is preferable to use high halogen content,
It is particularly preferable to use titanium tetrachloride (TiCl ₄ ). Various methods can be considered for reacting the product obtained by the above-mentioned aliphatic alcohol treatment with a halogen-containing titanium compound in the presence of an aromatic acid ester. For example, (1) the above product is first reacted with an aromatic acid ester, and then a halogen-containing titanium compound is added to this system to react, or (2) the above product is reacted with an aromatic acid ester and a halogen-containing titanium compound. Possible methods include adding compounds at the same time and causing a reaction. The conditions for these reactions are not particularly limited and may be selected appropriately depending on various conditions, etc., but for example, in the case of method (1) above, the product obtained by first treating with an aliphatic alcohol An aromatic acid ester is added to the solution, usually about 0.01 to 5 mol, preferably 0.05 to 1 mol, per 1 mol of magnesium in the product.
5 minutes to 5 hours at ℃, preferably 20 to 150℃
Allow to react for 20 minutes to 3 hours. Subsequently, a halogen-containing titanium compound is added to this reaction system in an amount of 0.03 to 100 mol, preferably 0.1 mol, per 1 mol of magnesium in the product.
Add in a range of ~20 mol and incubate at 10~200℃ for 30 minutes~10
The reaction time is preferably 1 to 5 hours at 30 to 150°C. In the reactions up to this point, it is also possible to use an inert solvent such as n-heptane, if necessary. After the reaction is completed, the solid product obtained is thoroughly washed with an inert solvent such as n-heptane. After the reaction, if only the liquid is removed and the above-described addition of the halogen-containing titanium compound and reaction are repeated,
This is preferred because the performance of the solid product as a catalyst is improved. In the present invention, the solid product thus obtained is used as component (A) (solid catalyst component) of an α-olefin polymerization catalyst. According to the present invention, α-olefin is produced using a catalyst consisting of two components (A) and (B), in which the above solid product is used as the (A) component and an organoaluminum compound is used as the (B) component. Carry out polymerization. When polymerizing α-olefin, the reaction system
(A) a dispersion of the above solid product as component; and (B)
An organic aluminum compound as a component is added, and then an α-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 5.0 mmol/, preferably 0.005 to 1.0 mmol/in terms of titanium atoms of component (A), and (B) The amount of the component is 1 to 1000 (molar ratio), preferably 5 to 500 (molar ratio) to the titanium atoms in component (A). In addition, (A) above,
Along with component (B), an aromatic acid ester as described above can also be added. The α-olefin pressure in the reaction system is preferably normal pressure to 50 kg/cm ² , and the reaction temperature is 20 kg/cm 2 .
~300°C, preferably 50-250°C. Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen. The reaction time is 0.1~
The time period may be appropriately selected from 10 hours, preferably from 0.5 to 5 hours. There are various organoaluminum compounds which are component (B) of the catalyst used in the method of the present invention, and there are no particular restrictions, but those represented by the general formula AlR ⁴ _n X ² _3-n are widely used. R ⁴ is an alkyl group, cycloalkyl group, or aryl group having 1 to 10 carbon atoms, m is a real number between 1 to 3, and X ² represents a halogen atom such as chlorine or bromine. Specifically, trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisopropylaluminium, triisobutylaluminum, and trioctylaluminum, and dialkyl compounds such as diethylaluminum monochloride, diisopropylaluminum monochloride, diisobutylaluminum monochloride, and dioctylaluminum monochloride. Aluminum monohalide is preferred, and mixtures thereof are also preferred. The α-olefin that can be polymerized by the method of the present invention is
Generally, those represented by the general formula R ³ -CH=CH ₂ (R ³ represents hydrogen, an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group), such as ethylene,
Including linear monoolefins such as propylene, butene-1, hexene-1, octene-1, etc., 4-
Examples include branched monoolefins such as methyl-pentene-1, dienes such as butadiene, and various others, and the present invention can be effectively used for homopolymerization of these or copolymerization of various α-olefins. According to the method of the present invention, the catalyst used is prepared in a short time and in a simple process, so that a catalyst with uniform properties is always obtained, and as a result, the reproducibility of the physical properties of the produced polymer is very good. It is. Further, according to the method of the present invention, the activity of the catalyst used is extremely high, and the resulting polymer has high stereoregularity and bulk density, resulting in extremely high product value. Therefore, since the method of the present invention is a method of highly active polymerization and a polymer with high stereoregularity is obtained, it is possible to simplify or omit the catalyst removal step and the amorphous polymer extraction step. ,
Very efficient polymerization can be carried out. Next, examples of the present invention will be shown. Note that all operations in the following examples were performed under an argon stream. Further, the catalytic activity and stereoregularity coefficient (II) determined in the examples were defined as follows. Catalyst activity: 70℃, 2 hours, propylene partial pressure 7
Weight (Kg) of total polymer produced per 1g of titanium atom during polymerization under conditions of Kg/ ^cm2 . 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 A well-dried 500ml volume Put 150 ml of dehydrated n-heptane into a four-necked flask, then introduce 10.0 g (88 mmol) of magnesium diethoxide, and add isopropyl alcohol while stirring.
1.06 g (17.5 mmol) was added, the temperature was raised to 80°C, and the mixture was treated for 1 hour. Next, lower the temperature to room temperature, remove the supernatant liquid, add 150 ml of n-heptane and stir.
The extraction was repeated twice for washing, and then 150 ml of n-heptane, 2.63 g (17.5 mmol) of ethyl benzoate, and 83 g (440 mmol) of titanium tetrachloride were introduced, the temperature was raised to the boiling point, and the mixture was reacted for 2 hours. After the reaction, the temperature was lowered to 80° C., the mixture was allowed to stand, and the supernatant liquid was extracted, 150 ml of n-heptane was newly added, and washing was performed by repeating stirring, standing, and draining twice. After that, add 83g of titanium tetrachloride again and boil until boiling point.
The reaction was carried out for a period of time, and after being allowed to stand still, the liquid was drained, and further n
-Add heptane, stir, let stand, and drain the liquid repeatedly until no chlorine ions are detected.
A solid catalyst component (A) was obtained. When Ti in the obtained solid catalyst component was measured by a colorimetric method, the amount supported was 48 mg-Ti/g-support. (2) Polymerization of propylene In a dry 1-volume stainless steel autoclave, 400 ml of degassed and purified n-heptane, 2.0 mmol of triethylaluminum, 0.6 mmol of methyl p-toluate (TM) and the solid obtained in (1) above were placed. Add 0.02 mmol of catalyst component as Ti to 70
The temperature was raised to ℃. Next, add 0.2Kg/ ^cm2 of hydrogen,
Propylene was continuously supplied so that the propylene partial pressure was 7 Kg/cm ² , and polymerization was carried out at 70° C. for 2 hours. After the reaction was completed, unreacted gas was removed and the mixture was filtered to obtain 184 g of white polypropylene powder. Also, the II of the obtained polypropylene is 98.0
%, and the bulk density was 0.33 g/ml. Also,
Soluble polymer by evaporating the liquid phase
6.8g was recovered. Examples 2 to 10 (1) Production of solid catalyst component In Example 1 (1), a solid catalyst component (A) was prepared by any of the following methods using a specified alcohol instead of isopropyl alcohol. Method: Same method as in Example 1 (1). Method: A method similar to Example 1(1) except that the washing step after the initial alcohol treatment of the magnesium compound was omitted. Method: A magnesium compound, a solvent, and an alcohol were added to a flask and treated at 40℃ for 1 hour. Next, an aromatic acid ester and a titanium compound were added to this system, and the mixture was treated at the boiling point for 2 hours, and then the temperature was increased to 80℃. After lowering, leaving to stand, draining liquid, and washing, a titanium compound was added again, and the procedure was carried out in the same manner as in Example 1 (1). (2) Polymerization of propylene In a dry 1-volume stainless steel autoclave, 400 ml of degassed and purified n-heptane, predetermined amounts of triethylaluminum (TEA), diethylaluminum chloride (DEAC), and methyl p-toluate, and the above (1) 0.02 mmol of the solid catalyst component obtained in ) was added as Ti, and the temperature was raised to 70°C.
Next, 0.2Kg/ ^cm2 of hydrogen was added, and the partial pressure of propylene was reduced to 7.
Propylene was continuously supplied at a rate of Kg/cm ² and polymerization was carried out at 70° C. for 2 hours. After the reaction is completed, unreacted gas is removed and further filtered.
A white polypropylene powder was obtained. The properties of the obtained polypropylene are shown in Table 1. Example 11 (1) Production of solid catalyst component In Example 1 (1), isopropyl alcohol was
A solid catalyst component (A) was obtained by carrying out the same operation as in Example 1 (1) except that 1.06 g was added. (2) Polymerization of ethylene In a dry 1-volume stainless steel autoclave, add 400 ml of degassed and purified n-heptane, 2 mmol of TEA, 2 mmol of DEAC, and 0.02 mmol of the solid catalyst component obtained in (1) above as Ti.
The temperature was raised to ℃. Next, 3 kg/cm ² of hydrogen was added, and polymerization was carried out at 80° C. for 1 hour while maintaining the total pressure at 12.5 kg/cm ² with ethylene. After the reaction was completed, unreacted gas was removed and the mixture was filtered to obtain white polyethylene powder. The properties of the obtained polyethylene are shown in Table 1. Comparative Example 1 (1) Production of solid catalyst component In a well-dried 500 ml four-necked flask, 150 ml of dehydrated and purified n-heptane, 10.0 g (88 mmol) of magnesium diethoxide, and 2.64 g (17.6 mmol) of ethyl benzoate were added. 1 under reflux.
Time reacted. Then, the temperature was raised to 70°C, 83 g (440 mmol) of titanium tetrachloride was added dropwise over 30 minutes, and the mixture was reacted under reflux for 3 hours. Thereafter, the temperature was raised to 80°C, the supernatant liquid was drawn out, 250 ml of n-heptane was added, and stirring, standing, and liquid removal were repeated until no chlorine ions were detected for washing, thereby obtaining a solid catalyst component. (2) Polymerization of propylene In Example 1 (2), the above solid catalyst component was
Example 1 except that the one obtained in (1) was used
The same operation as (2) was performed. The results are shown in Table 1. Comparative Example 2 (1) Production of solid catalyst component Example 1 except that phenol was used instead of isopropyl alcohol in Example 1 (1).
A solid catalyst component was obtained by performing the same operation as in (1). (2) Polymerization of propylene In Example 1 (2), the above solid catalyst component was
Example 1 except that the one obtained in (1) was used
The same operation as (2) was performed. The results are shown in Table 1.

[Table] *1 Molar ratio to magnesium dialkoxide *2 Units are mg-Ti/g-support

[Brief explanation of drawings]

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. A method for polymerizing α-olefin using (A) a solid catalyst component containing a magnesium compound and a titanium compound and (B) a catalyst containing an organometallic compound as a component, which has the general formula Mg(OR ¹ ) ₂ [In the formula, ^R1 represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, or an aralkyl group. ] is treated with an aliphatic alcohol,
Then in the presence of an aromatic acid ester the general formula Ti
(OR ² ) _o X ¹ _4-o [In the formula, R ² represents an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 10 carbon atoms, and X ¹ represents a halogen atom. Further, n is a real number satisfying 0≦n<4. A solid product obtained by reacting with a halogen-containing titanium compound represented by ] is used as the (A) component of the above catalyst, and an organoaluminum compound is used as the (B) component of the above catalyst. α
- Olefin polymerization method. 2 Magnesium dialkoxide represented by the general formula Mg(OR ¹ ) ₂ is magnesium dimethoxide,
2. The method according to claim 1, which is magnesium diethoxide, magnesium dipropoxide, magnesium dibutoxide or magnesium dicyclohexoxide. 3. The α-olefin is represented by the general formula R ³ —CH=CH ₂ (wherein R ³ represents hydrogen, an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group). The method described in Section 1.