JPH06256412A - Method of alpha-olefin polymerization - Google Patents

Abstract

PURPOSE:To provide a method, by which a highly stereoregular alpha-olefin polymer with high melt flowability is produced. CONSTITUTION:An alpha-olefin is polymerized by using a catalyst which comprises a solid catalyst component essentially contg. magnesium, titanium, a halogen, and an electron donor, an organoaluminum compd., and t- butylethyldimethoxysilane.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention uses a highly active catalyst to obtain α
-It relates to a method of polymerizing an olefin to produce an α-olefin body having high stereoregularity and high melt fluidity.

[0002]

2. Description of the Related Art In recent years, in order to polymerize .alpha.-olefins, a solid catalyst component which requires magnesium, titanium, a halogen element, and an electron donor as an essential component, and an organometallic group I to III metal. A highly active catalyst system comprising a compound and an electron donor as a third component is disclosed in JP-A-57-633.
Many proposals are made in JP-A No. 10-58, JP-A No. 58-83016, JP-A No. 59-58010, and JP-A No. 60-44507. Furthermore, JP-A-62-11705 and JP-A-63-258907
Japanese Unexamined Patent Publications and the like disclose a polymerization catalyst characterized by using a specific silicate as the third component. Generally, in the case of producing an α-olefin polymer, in order to improve the melt flowability of the polymer, a chain transfer agent such as hydrogen is used, and a method of increasing the melt flow rate (MI) of the polymer is used. There is.

However, in the above catalyst system, usually,
When the amount of chain transfer agent such as hydrogen used is increased to improve the melt fluidity of the polymer, the stereoregularity (boiling heptane insoluble matter, HI) of the polymer is generally greatly reduced. Therefore, the various high-activity catalysts described in the above publications are said to be excellent catalysts which are highly active and improve the stereoregularity of the polymer, but particularly obtain a polymer having high melt fluidity. In this case, the above-mentioned drawback becomes a big problem, and its solution is desired.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for producing an α-olefin polymer having a high stereoregularity and a high melt fluidity by polymerizing an α-olefin using a highly active catalyst.

[0005]

The present invention relates to a solid catalyst component which essentially contains magnesium, titanium, a halogen element and an electron donor as component [A], an organoaluminum compound as component [B], and a component. [C] as t-
Provided is a method for polymerizing an α-olefin, which comprises polymerizing the α-olefin in the presence of a catalyst composed of butylethyldimethoxysilane.

In the present invention, a solid catalyst component containing magnesium, titanium, a halogen element, and an electron donor as essential components is used as the component [A]. The method for producing the catalyst solid component is not particularly limited, and examples thereof include JP-A-54-94590, JP-A-56-55405, JP-A-56-45909, and JP-A-56-163.
102 publication, 57-63310 publication, 57-115408 publication,
58-83006, 58-83016, 58-138707, 59-149905, 60-23404, 60-3.
The methods proposed in JP 2805, JP 61-18330, JP 61-55104, JP-A-2-77413 and JP 2-117905 can be used. As a typical manufacturing method,
A method in which a magnesium compound such as magnesium chloride, an electron donor, and a titanium halide compound such as TiCl ₄ are co-ground, a magnesium compound and an electron donor are dissolved in a solvent, and the titanium halide compound is added to this solution to form a catalyst. Examples thereof include a method of depositing a solid.

As the component [A], the solid catalyst components described in JP-A-60-152511, JP-A-61-31402 and JP-A-62-81405 are particularly preferable for achieving the effect of the present invention. preferable. According to the manufacturing method thereof described, wherein an aluminum halide (wherein, X ¹ is a chlorine atom, a bromine atom, or iodine atom.) Represented by AlX ¹ ₃ and, wherein R ¹ _n Si (OR ² )
A silicon compound represented by _4-n (in the formula, R ¹ and R ² each represent an alkyl group having 1 to 8 carbon atoms or a phenyl group, and n is an integer of 0 to 3). , A magnesium compound represented by the formula R ³ MgX ² (in the formula, R ³ represents an alkyl group having 1 to 8 carbon atoms, and X ² represents a chlorine atom, a bromine atom or an iodine atom). To precipitate a solid. As the aluminum halide that can be used in the above reaction, anhydrous aluminum halide is preferable, but it is difficult to use completely anhydrous aluminum halide due to hygroscopicity, and aluminum halide containing a small amount of water should also be used. You can Specific examples of aluminum halides include aluminum trichloride, aluminum tribromide and aluminum triiodide, with aluminum trichloride being particularly preferred.

Specific examples of the silicon compound used in the above reaction include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, methyltriethoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltributoxysilane and dimethyl. Diethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane,
Examples thereof include trimethyl monoethoxysilane and trimethyl monobutoxy silane. In particular, methylphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane and dimethyldiethoxysilane are preferable. The amount of the compound used in the reaction between the aluminum halide and the silicon compound is usually 0.4 to 1.5, preferably 0.7 to 1. in terms of element ratio (Al / Si).
It is within the range of 3, and it is preferable to use an inert solvent such as hexane and toluene in the reaction. The reaction temperature is generally 10-100 ° C, preferably 20-80 ° C, and the reaction time is generally 0.2-5 hours, preferably 0.5-3 hours.

Specific examples of the magnesium compound used in the above reaction include ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, octyl magnesium chloride, ethyl magnesium bromide, propyl magnesium bromide, butyl magnesium bromide and ethyl. Examples include magnesium iodide. As the solvent of the magnesium 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 to 3, preferably 1.5 to 2.3 in terms of the element ratio (Mg / Al) to the aluminum halide used in the preparation of the reaction product of the aluminum halide and the silicon compound. It is a range. The reaction temperature is usually -50 to 100 ° C, preferably-
20 to 50 ° C, reaction time is usually 0.2 to 5 hours, preferably
0.5 to 3 hours.

The white solid obtained in the reaction of an aluminum halide with a silicon compound and subsequently with a Grignard compound is contact-treated with an electron donor and a titanium halide compound. As a method of contact treatment,
(1) A method of treating a solid with a titanium halide compound, then treating with an electron donor, and then again treating with a titanium halide compound, and (2) treating the solid with a titanium halide compound and an electron donor. Then, a well-known method such as a method of treating with a titanium halide compound after the treatment with 1 can be adopted. For example, the above solid is dispersed in an inert solvent and the electron donor or / and the titanium halide compound is dissolved therein, or an electron donor or / and a liquid titanium halide compound is used without using an inert solvent. Disperse the solid in. In this case, the contact treatment between the solid and the electron donor or / and the titanium halide compound can be carried out under stirring at a temperature of usually 50 to 150 ° C. and a contact time of 0.2 to 5 hours, although there is no particular limitation. Further, this contact treatment can be performed multiple times.

Titanium halide compounds that can be used in the contact treatment include those represented by the formula Ti (OR) _p X _4-P (p is an integer of 0 to 3,
X represents a halogen atom. ). Specific examples include tetrachlorotitanium, tetrabromotitanium, trichloromonobutoxy titanium, tribromomonoethoxy titanium, trichloromonoisopropoxy titanium, dichlorodiethoxy titanium, dichlorodibutoxy titanium, monochlorotriethoxy titanium, monochlorotributoxy titanium. Can be mentioned. Particularly, tetrachlorotitanium and trichloromonobutoxytitanium are preferable.

The electron donor used in the above contact treatment is preferably an aromatic ester, particularly an orthophthalic acid diester. Specific examples of the diester include diethyl orthophthalate, diisobutyl orthophthalate, dipentyl orthophthalate, dihexyl orthophthalate, di-2-ethylhexyl orthophthalate, and di-n-heptyl orthophthalate. After the above-mentioned catalytic treatment, the treated solid is generally separated from the treated mixture and thoroughly washed with an inert solvent, and the obtained solid is used as the catalyst solid component [A] of the present invention as an α-olefin polymerization catalyst. be able to.

As the organoaluminum compound as the component [B] of the present invention, alkylaluminum, halogenoalkylaluminum and the like can be used, but alkylaluminum is preferred. Trialkylaluminum is particularly preferable, and specific examples thereof include trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and the like. Any of the organoaluminum compounds may 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 0.1 to 500, preferably 0.5 to 500 in terms of the element ratio (Al / Ti) to titanium of the catalyst solid component [A].
It is 150.

As the component [C] of the present invention, t-butylethyldimethoxysilane is used. The amount of the component [C] used is preferably 0.01 to 1 in terms of the element ratio (Si / Al) of the silane of the component [C] to the aluminum of the component [B], and more preferably 0.05.
~ 0.33 is preferred.

In the present invention, a chain transfer agent such as hydrogen can be used. The amount of hydrogen used for producing an α-olefin polymer having a desired stereoregularity (HI) and melt flowability (MI) can be appropriately determined depending on the polymerization method and the polymerization conditions, but usually, Hydrogen partial pressure 0.
It is in the range of 05 to 1.0.

In the present invention, during the α-olefin polymerization,
The order of contacting each catalyst component is not particularly limited, but t-butylethyldimethoxysilane of component [C] and component [A]
It is less preferred that only the catalytic solid of 1) comes into direct contact.

Examples of the α-olefin used in the present invention include propylene, 1-butene, 1-hexene, 4-methylpentene-1,1-octene and the like. In the present invention, the above α-olefin can be homopolymerized or copolymerized, and further the above α-olefin and ethylene can be copolymerized. In the present invention, propylene can be homopolymerized, and then ethylene or a mixture of ethylene and propylene can be copolymerized in the presence of the homopolymer to produce a propylene block copolymer.

As the polymerization method in the present invention, a slurry polymerization method using a non-polar 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
~ 200kg / cm ² , preferably 10 ~ 80kg / cm ² , the polymerization temperature is usually 10 ~ 100 ℃, preferably 30 ~ 90 ℃, the polymerization time is usually
It is in the range of 0.1 to 10 hours, preferably 0.5 to 7 hours.

Further, in the present invention, it is preferable to carry out the main polymerization after prepolymerizing the olefin according to the above-mentioned various polymerization methods. The prepolymerization is, for example, usually -10 to 100.
The temperature can be 1 to 180 minutes at a temperature of 1 to 180 minutes under the condition that 1 to 100 g of the olefin polymer is obtained per 0.1 mg of the transition metal atom in the solid catalyst.

[0021]

INDUSTRIAL APPLICABILITY In the present invention, when an α-olefin is produced by using a highly active catalyst, the stereoregularity is high,
Moreover, a polymer having a high melt fluidity can be provided.

EXAMPLES Examples of the present invention will be described below. In the examples, “polymerization activity” means a catalyst solid component.
The yield (g) of the polymer produced per 1 g, and the stereoregularity (HI) of the polymer indicate the ratio (%) of the balance of the polymer extracted with hot heptane for 20 hours. The melt flowability (MI) of the polymer is A
230 ° C measured according to STM D-1238, under a load of 2.16 kg,
It represents the weight (g) of the molten polymer for 10 minutes.

Example 1 (1) Preparation of solid catalyst component [A] 15 mmol of anhydrous aluminum chloride was added to 40 ml of toluene, and then 15 mmol of methyltriethoxysilane was added dropwise with stirring. The reaction was carried out 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 titanium tetrachloride and 3.3 mmol of di-n-heptyl phthalate were suspended in this suspension.
Mmol was added, and the mixture was reacted at 90 ° C. for 1 hour with stirring.
The solid was filtered off at the same temperature and washed with toluene and then n-heptane. Furthermore, the solid was suspended again in 30 ml of toluene, 150 mmol of titanium tetrachloride was added, and the mixture was stirred at 90 ° C.
And reacted for 1 hour. The solid was filtered off at the same temperature, and the solid was washed with toluene and then n-heptane. The titanium content in the obtained catalyst solid component was 3.55% by weight. This solid was suspended in 80 ml of heptane to prepare a heptane slurry of catalyst solid components.

(2) Polymerization of Propylene A glass ampoule containing a heptane slurry (catalyst solid component of 7.9 mg) as a catalyst solid component was mounted in an autoclave with an internal volume of 2 L equipped with a stirrer, and then the autoclave was replaced with nitrogen. . Then triethyl aluminum
2.1 ml of n-heptane solution containing 2.1 mmol was charged to the autoclave. Furthermore, 1.74 ml of an n-heptane solution containing 0.35 mmol of t-butylethyldimethoxysilane was charged as a third component. Then, after introducing 2.0 kg / cm ² G of hydrogen, 1200 ml of liquid propylene was introduced and the autoclave was shaken. The autoclave was cooled to 10 ° C., and when the stirring was started, the glass ampoule containing the solid catalyst component was crushed and prepolymerized for 10 minutes. Continue inside the autoclave
The temperature was raised to 70 ° C and polymerization was carried out at 70 ° C for 1 hour. After the polymerization was completed, unreacted propylene gas was released and the polymer was heated at 50 ° C for 20
After drying under reduced pressure for a while, white powdery polypropylene was obtained. The measurement results of the polymerization activity and the characteristics of the polymer are shown in Table 1.

Examples 2 to 3 Polymerization was carried out in the same manner as in Example 1 except that the amount of hydrogen used was changed. The measurement results of the polymerization activity and the characteristics of the polymer are shown in Table 1.

Comparative Examples 1 to 6 The procedure of Example 1 was repeated, except that the silanes shown in Table 1 were used instead of t-butylethyldimethoxysilane, and the amount of hydrogen used was changed. The measurement results of the polymerization activity and the characteristics of the polymer are shown in Table 1.

[0027]

[Table 1]

[Brief description of drawings]

FIG. 1 is a flow chart showing a preparation process and a polymerization method of a catalyst component of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichiro Yamada 8-1 Goi Minamikaigan, Ichihara City, Chiba Ube Industries Ltd. Chiba Research Institute

Claims (1)

[Claims] 1. A catalyst solid component essentially comprising magnesium, titanium, a halogen element, and an electron donor as component [A], an organoaluminum compound as component [B], and t-butylethyldimethoxysilane as component [C]. A method for polymerizing an α-olefin, which comprises polymerizing an α-olefin in the presence of a catalyst consisting of