JPH05310827A - Polymerization of alpha-olefin - Google Patents

Abstract

PURPOSE:To obtain an alpha-olefin polymer having high stereoregularity, a practical molecular weight and a broad molecular weight distribution at high catalytic activity. CONSTITUTION:An alpha-olefin is polymerized in the presence of a catalyst system comprising a solid catalyst component (prepared by treating a carrier obtained by reacting an aluminum halide with a silicon compound and a magnesium compound with a titanium halide and an aromatic carboxylic acid ester and retreating the treated carrier with a titanium tetrahalide, provided that at least either of the titanium tetrahalides contains a tetraalkoxytitanium), an organolauminum compound, and an electron donor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an α-olefin homopolymer having a high stereoregularity and a wide molecular weight distribution, or a copolymer with another α-olefin.

[0002]

PRIOR ART AND PROBLEMS THEREOF So far, in order to improve the stereoregularity of α-olefins, a solid catalyst component containing magnesium, titanium, a halogen element, and an electron donor is essential, and the periodic tables 1-3. Many highly active catalyst systems have been proposed which consist of an organometallic compound of a group metal and an electron donor as a third component. As the third component, JP-A-57
No. 63310, No. 58-83016, No. 5
No. 8-138707, No. 60-23404,
61-18330, 61-55104, JP-A-2-77413, and 2-117905.
For example, silicon compounds such as dialkyl dialkoxy silanes are described in the publications and the like.
Further, JP-A-54-94590 discloses that a polysiloxane compound is used as an electron donor as a third component in combination with an organic carboxylic acid ester. JP 146914 discloses the use of polysiloxane compounds in block polymerization in a second stage gas phase process following the first stage α-olefin polymerization.

The various silicon compounds described in the above publications are said to constitute a highly active catalyst system and are excellent third catalyst components for improving the stereoregularity of the polymer.
However, catalyst systems containing these silicon compounds are still insufficient in terms of stereoregularity and catalytic activity of the polymer.
Therefore, in order to sufficiently reduce the concentration of the catalyst residue in the polymer in the deashing-free process, it was necessary to carry out a complicated step such as preactivation of the catalyst or prepolymerization.
Also, the molecular weight distribution of the polymer produced by the catalyst system described in the above publications is generally narrow, and the viscoelasticity when the polymer is melted is small, which is an important problem in molding. In JP-A-3-43406 and JP-A-3-56508, a solid component essentially containing magnesium, titanium, a halogen element, and an electron donor is further mixed with an organic transition metal compound having a cyclopentadienyl group. Alternatively, a method using a contact-treated solid catalyst component is disclosed. However, the polymer produced by using this solid catalyst component can obtain only a polymer having a high molecular weight and a low melt flow value (MI value) under ordinary hydrogen pressure. Therefore, high M.I. I. In order to obtain the value, there is a practical problem in terms of productivity and safety in that the polymerization temperature is lowered, the monomer concentration is lowered, or a pressure resistant device is required. When α-olefin polymerization is carried out by a deashing process, α-olefin having a small catalyst residue in the polymer, high stereoregularity, a practical molecular weight and a wide molecular weight distribution
Development of a catalyst system capable of producing an olefin polymer is desired.

[0004]

The present invention has high activity,
An object of the present invention is to provide a method for producing an α-olefin polymer having high stereoregularity, a practical molecular weight, and a wide molecular weight distribution.

[0005]

The present invention relates to (1) aluminum halide and the formula R ¹ _n Si (OR ² )
_4-n [I] (In the formula, R ¹ represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group, R ² represents an alkyl group having 1 to 8 carbon atoms, and n is 0, 1 , 2 or 3), and the reaction product obtained in step (2) of step (1) is converted into the compound represented by the formula R ³ MgX ¹
[II] (in the formula, R ³ represents an alkyl group having 1 to 8 carbon atoms, X ¹ represents a halogen atom), and reacted with a magnesium compound to obtain (3) step (2). The carrier is subjected to a contact treatment with a titanium tetrahalide represented by the formula TiX ² ₄ [III] (wherein X ² represents a halogen atom) and an aromatic carboxylic acid ester, and obtained in the step (4) step (3). The solid catalyst component [A] obtained by contact-treating the treated solid again with titanium tetrahalide (provided that at least one of the titanium tetrahalides in step (3) or step (4) has the formula Ti (OR ⁴ ) ₄
A tetraalkoxytitanium represented by [IV] (wherein R ⁴ represents an alkyl group having 1 to 8 carbon atoms or a phenyl group) is TiX ² ₄ : Ti (OR ⁴ ) ₄ = 100: 0.05.
Contained in a molar ratio of ˜5), formula AlR ⁵ ₃ [V]
(In the formula, R ⁵ represents an alkyl group having 2 to 8 carbon atoms), the α-olefin is polymerized in the presence of a catalyst obtained from the organoaluminum compound [B] and the electron donor [C]. And a method for polymerizing an α-olefin.

Specific examples of the aluminum halide in the step (1) of the present invention include aluminum trichloride, aluminum tribromide and aluminum triiodide, with aluminum trichloride being particularly preferred.

Specific examples of the organosilicon compound represented by the formula [I] include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane and tetra-n-.
Butoxysilane, tetraisopentoxysilane, tetra-n-hexoxysilane, methyltrimethoxysilane,
Methyltriethoxysilane, methyltri-n-butoxysilane, methyltriisopentoxysilane, methyltri-n-hexoxysilane, ethyltriethoxysilane,
Ethyltriisopropoxysilane, ethyltriisopentoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, isopentyltriethoxysilane, isopentyltri-n-butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxy Silane, dimethyldiisopentoxysilane, diethyldiethoxysilane, diethyldiisopentoxysilane, diisobutyldiisopentoxysilane, di-n-butyldiethoxysilane, diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxy Silane,
Trimethylisobutoxysilane, triethylisopropoxysilane, tri-n-propylethoxysilane, tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltriethoxysilane, phenyltriisobutoxysilane, phenyltriisopentoxysilane, Diphenyldiethoxysilane, diphenyldiisopentoxysilane, diphenyldioctoxysilane, triphenylmethoxysilane, triphenylethoxysilane, triphenylisopentoxysilane, benzyltriethoxysilane, benzyltributoxysilane, dibenzyldiethoxysilane Is mentioned. Of these, alkylalkoxysilanes such as methyltriethoxysilane are preferably used.

The proportion of aluminum halide used in the reaction between the aluminum halide and the organosilicon compound is
It is preferably 0.1 to 10 mol, and particularly preferably 0.1 to 2 mol, per mol of the organosilicon compound. The reaction is usually carried out by stirring both compounds in an inert organic solvent at a temperature in the range of -50 to 100 ° C for 0.1 to 2 hours. The reaction proceeds exothermically and the reaction product is obtained as a solution in an inert organic solvent.

Specific examples of the magnesium compound represented by the formula [II] in the step (2) include ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, octyl magnesium chloride, ethyl magnesium bromide and propyl magnesium. Examples thereof include bromide, butyl magnesium bromide, and ethyl magnesium iodide. As the solvent for the Grignard compound, for example, an aliphatic ether such as diethyl ether, dibutyl ether, diisopropyl ether, diisoamyl ether, or an aliphatic cyclic ether such as tetrahydrofuran can be used. The amount of the magnesium compound used is usually 0.5 in terms of the element ratio (Mg / Al) to the aluminum halide used to prepare the reaction product of the aluminum halide and the organosilicon compound.
The range is from 3 to 3, preferably from 1.5 to 2.3. The reaction temperature is generally −50 to 100 ° C., preferably −20 to 50.
C, reaction time is usually 0.2 to 5 hours, preferably 0.5
~ 3 hours.

In step (3), the carrier obtained in the reaction of step (2) is catalytically treated with titanium tetrahalide and an aromatic carboxylic acid ester. Alternatively, the carrier is contact-treated with titanium tetrahalide and then with an aromatic carboxylic acid ester. As the contact treatment, a conventionally well-known method can be adopted. For example, the above solid is dispersed in an inert solvent, and the aromatic carboxylic acid ester and titanium tetrahalide are dissolved therein, or the aromatic carboxylic acid ester and the tetrahalogenated titanium are dissolved in the solvent without using an inert solvent. Disperse the solid. In this case, the contact treatment condition is that the temperature is usually 50 with stirring.
~ 150 ° C, the contact time is not particularly limited, but is usually 0.2 ~
It can be done in 5 hours. Further, this contact treatment can be performed multiple times.

As the aromatic carboxylic acid ester used in the above contact treatment, orthophthalic acid diester is particularly preferable. Specific examples of the diester include diethyl orthophthalate, diisobutyl orthophthalate, dipentyl orthophthalate, dihexyl orthophthalate, di-2-ethylhexyl orthophthalate, and di-n orthophthalate.
-Heptyl.

Specific examples of the titanium tetrahalide represented by the formula [III] include tetrachlorotitanium, tetrabromotitanium and tetraiodide titanium. Particularly, tetrachlorotitanium is preferable.

The treated solid obtained by the contact treatment in step (3) is again contact-treated with titanium tetrahalide. The conditions such as the amount of titanium tetrahalide used, the contact temperature, and the contact time are the same as those for preparing the treated solid. The solid catalyst component [A] is obtained by separating from this treatment mixture and thoroughly washing with an inert solvent.

In the present invention, at least one of the titanium tetrahalides in step (3) or step (4) has the formula Ti (OR ⁴ ) ₄ [IV] (wherein R ⁴ has 1 to 8 carbon atoms). A tetraalkoxytitanium represented by an alkyl group or a phenyl group) is represented by TiX ² ₄ : Ti
(OR ⁴ ) ₄ = 100: contained in a molar ratio of 0.05 to 5. If the molar ratio of titanium tetrahalide to tetraalkoxytitanium is smaller than the above range, the molecular weight distribution of the resulting polymer will be small, and if it is larger than the above range, the polymerization activity and stereoregularity will be reduced. The amount of the titanium compound used is preferably 1 mol or more, and particularly preferably 2 to 100 mol, per 1 mol of the magnesium compound used when preparing the carrier.

Specific examples of the tetraalkoxytitanium represented by the formula [IV] include tetraethoxytitanium, tetrapropoxytitanium and tetrabutoxytitanium. Particularly, tetrabutoxy titanium is preferable.

In the present invention, the solid catalyst component [A],
The α-olefin is polymerized in the presence of a catalyst obtained from the organoaluminum compound [B] represented by the formula [V] and the electron donor [C]. Organic aluminum compound [B]
Specific examples of trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and the like. Any of the above organoaluminum compounds can be used as a mixture. Further, polyaluminoxane obtained by the reaction of alkylaluminum and water can be used as well.

The amount of the organoaluminum compound used as the α-olefin polymerization catalyst is usually 0.1 to 500 mol, preferably 0.5 to 150 mol, per gram atom of titanium in the solid catalyst component [A]. is there.

Examples of the electron donor [C] of the present invention include organic acid esters, inorganic acid esters, acid halides, ethers,
Acid amides, N, N-dialkyl acid amides, amines, nitriles, acid anhydrides, alkoxysilanes, ketones, alcohols, aldehydes, carboxylic acids, isocyanates and the like can be used. In particular, alkoxysilanes are preferably used.

Specific examples of the alkoxysilanes include tetramethoxysilane, tetraethoxysilane and tetra-silane.
n-propoxysilane, tetra-n-butoxysilane,
Tetra-isopentoxysilane, tetra-n-hexoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, methyltriisopentoxysilane, methyltri-n-hexoxysilane, ethyltriethoxysilane, ethyltriethoxysilane Isopropoxysilane, ethyltriisopentoxysilane,
n-Butyltriethoxysilane, isobutyltriethoxysilane, isopentyltriethoxysilane, isopentyltri-n-butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, dimethyldiisopentoxysilane, diethyldiethoxysilane , Diethyldiisopentoxysilane, diisobutyldiisopentoxysilane, di-n-butyldiethoxysilane, diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethylisopropoxysilane, tri -N-propylethoxysilane, tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltriethoxysilane, phenyltriisobutoxysilane, phenyltri Seo pent silane, diphenyl diethoxy silane, diphenyl isopentoxycarbonyl silane,
Diphenyldioctoxysilane, triphenylmethoxysilane, phenylmethyldimethoxysilane, triphenylethoxysilane, triphenylisopentoxysilane, benzyltriethoxysilane, benzyltributoxysilane, dibenzyldiethoxysilane, cyclopentyltrimethoxysilane, 2 -Methylcyclopentyltrimethoxysilane, 2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,
Tricyclopentyl ethoxysilane etc. are mentioned.
Two or more kinds of these electron donors may be used in combination. The amount of the electron donor [C] used is 0.01 to 1 mol, particularly 0.05 to 1 mol, per 1 mol of the organoaluminum compound [B].
It is preferably 0.5 mol.

In the present invention, during the α-olefin polymerization,
The order of contact of the respective catalyst components is not particularly limited, but it is not so preferable that only the catalyst solids of the component [C] and the component [A] are in direct contact.

Examples of the α-olefin used in the present invention include ethylene, propylene, 1-butene, 1-hexene, 4-methylpentene-1,1-octene and the like.

As the polymerization method in the present invention, a slurry polymerization method using a nonpolar solvent such as hexane or heptane, a gas phase polymerization method in which a monomer is brought into contact with a catalyst in a gas state, or a monomer in a liquid state as a solvent is used. A bulk polymerization method or the like in which the polymerization is performed can be adopted. Polymerization pressure is 1
~ 200 kg / cm ² , preferably 10-80 kg / c
m ² , the polymerization temperature is usually 10 to 100 ° C., preferably 30
The polymerization time is usually 0.1 to 10 hours, preferably 0.5 to 7 hours. Further, hydrogen can be made to coexist as a molecular weight regulator of the produced polymer.

[0023]

The highly active catalyst system of the present invention has a very low content of catalyst residue in the polymer produced when an α-olefin is produced by a deashing process, and the stereoregularity of the polymer is high. It has excellent practical molecular weight and wide molecular weight distribution.

EXAMPLES Examples of the present invention will be described below. In the examples, "polymerization activity" is the yield (kg) of the polymer produced per 1 g of the catalyst solid component, and the stereoregularity of the polymer is the ratio (%) of the balance of the polymer extracted with hot heptane for 20 hours. Indicates. The molecular weight distribution of the polymer was measured by GPC using polystyrene as a standard sample.
The value (M _w / M _n ) is shown. MI value is 230 ° C, 2.1
The weight (g) of the molten polymer for 10 minutes under a load of 6 kg is shown.

Example 1 (1) Preparation of solid catalyst component [A] 15 mmol of anhydrous aluminum trichloride was added to 40 m of toluene.
Then, 15 mmol of methyltriethoxysilane was added dropwise with stirring, and after completion of the addition, the reaction was carried out at 25 ° C. for 1 hour. After cooling the reaction product to -5 ° C, 18 ml of diisopropyl ether containing 30 mmol of butylmagnesium chloride was added dropwise to the reaction product over 30 minutes with stirring, and the temperature of the reaction solution was adjusted to within the range of -5 to 0 ° C. I kept it. After the dropping was completed, the temperature was gradually raised and the reaction was continued at 30 ° C. for 1 hour. The precipitated solid was filtered off and washed with toluene and n-heptane. Next, 4.9 g of the obtained solid was suspended in 30 ml of toluene, and 150 mmol of a titanium mixture of tetrachlorotitanium and tetrabutoxytitanium (tetrachlorotitanium: tetrabutoxytitanium = 9) was suspended in this suspension.
(9.5: 0.5 molar ratio) and 3.3 mmol of di-n-heptyl phthalate were added, and the mixture was reacted under stirring at 90 ° C. for 1 hour. The solid was filtered off at the same temperature, toluene and then n-
Wash with heptane. Further, the solid is again added with toluene 30
Suspend in 9 ml, add the above titanium mixture and under stirring 9
The reaction was carried out at 0 ° C for 1 hour. The solid was filtered off at the same temperature, and the solid was washed with toluene and then with n-heptane. The titanium content in the obtained solid component was 4.08% by weight.

(2) Polymerization of Propylene Heptane slurry of solid catalyst component (11.85 as solid catalyst component) in an autoclave with an internal volume of 2 L equipped with a stirrer.
After mounting a glass ampoule containing (mg), the inside of the autoclave was replaced with nitrogen. Next, an autoclave was charged with an n-heptane solution containing 0.45 mmol of phenylmethyldimethoxy and 2.0 ml of an n-heptane solution containing 2.70 mmol of triethylaluminum. Further, after introducing hydrogen at 0.2 kg / cm ² G, 1200 ml of liquid propylene was introduced and the autoclave was shaken. Raise the temperature inside the autoclave to 65 ° C,
When the stirring was started, the glass ampoule containing the solid catalyst component was crushed, and polymerization was carried out at 65 ° C. for 1 hour. After the polymerization was completed, unreacted propylene gas was released, and the polymer was dried under reduced pressure at 60 ° C. for 20 hours to obtain white powdery polypropylene.
Table 1 shows the measurement results of the polymerization activity and the characteristics of the polymer.
Shown in.

Example 2 In the preparation of the solid catalyst component [A] of Example 1, except that the mixing ratio of tetrachlorotitanium and tetrabutoxytitanium (tetrachlorotitanium: tetrabutoxytitanium = 97: 3 molar ratio) was changed. Is performed in the same manner, and the titanium content is 4.
90% by weight of a solid catalyst component [A] was obtained. Polymerization was performed in the same manner as in Example 1 to obtain white powdery polypropylene. Table 1 shows the measurement results of the polymerization activity and the characteristics of the polymer.

Comparative Example 1 In the preparation of the solid catalyst component [A] of Example 1, the same procedure was carried out except that 150 mmol of tetrachlorotitanium was used instead of the mixture, and the titanium content was 3.55% by weight. The solid catalyst component [A] of Polymerization was performed in the same manner as in Example 1 to obtain white powdery polypropylene. Table 1 shows the measurement results of the polymerization activity and the characteristics of the polymer.

Comparative Example 2 In the preparation of the solid catalyst component [A] of Example 1, except that the mixing ratio of tetrachlorotitanium and tetrabutoxytitanium (tetrachlorotitanium: tetrabutoxytitanium = 50: 50 molar ratio) was changed. The same procedure was performed to obtain a solid catalyst component [A] having a titanium content of 2.50% by weight. Example 1
Polymerization was carried out in the same manner as above to obtain white powdery polypropylene. Table 1 shows the measurement results of the polymerization activity and the characteristics of the polymer.

[0030]

[Table 1]

[Brief description of drawings]

FIG. 1 is a flow chart showing a polymerization method of the present invention and steps for preparing a catalyst component used in the polymerization.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shinichiro Yamada 8-1 Goi Minamikaigan, Ichihara City, Chiba Ube Industries Ltd. Chiba Research Institute

Claims (1)

[Claims] 1. (1) Aluminum halide and formula R ¹
_n Si (OR ² ) _4-n [I] (In the formula, R ¹ represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group, and R ² represents an alkyl group having 1 to 8 carbon atoms. , N is 0,
1, 2, or 3), and the reaction product obtained in (2) step (1) is reacted with the formula R ³ M
gX ¹ [II] (in the formula, R ³ represents an alkyl group having 1 to 8 carbon atoms, X ¹ represents a halogen atom), and reacted with a magnesium compound to obtain (3) step (2) The resulting carrier is of the formula TiX ² ₄
[III] (in the formula, X ² represents a halogen atom) is subjected to a contact treatment with a titanium tetrahalide and an aromatic carboxylic acid ester, and (4) the treated solid obtained in the step (3) is again treated with Solid catalyst component [A] obtained by contact treatment with titanium tetrahalide (provided that at least one of the titanium tetrahalides in step (3) or step (4) has the formula Ti (O
R ⁴ ) ₄ [IV] (in the formula, R ⁴ represents an alkyl group having 1 to 8 carbon atoms or a phenyl group), a tetraalkoxy titanium represented by TiX ² ₄ : Ti (OR ⁴ ) ₄ = 10.
0: 0.05 to 5) and an organoaluminum compound [B] represented by the formula AlR ⁵ ₃ [V] (in the formula, R ⁵ represents an alkyl group having 2 to 8 carbon atoms). And an α-olefin polymerized in the presence of a catalyst obtained from the electron donor [C].
Method for polymerizing olefins.