JPH07224107A - Prepolymerization of olefin - Google Patents

Abstract

PURPOSE:To obtain a highly stereoregular polymer in high polymerization activity by polymerizing an alpha-olefin in the presence of a catalytic system composed of a Ti compound, trialkylaluminum compound, organosilicon compound and halogen atom-contg. Lewis acid. CONSTITUTION:Using a catalyst composed of (A) a titanium-contg. component prepared by agitating at 125 deg.C anhydrous magnesium chloride, decane and 2-ethylhexyl alcohol followed by addition of phthalic anhydride to form a homogeneous solution followed by making a reaction by adding titanium tetrachloride and diisobutyl phthalate to the solution and then by putting the solid produced to filtration, (B) an organoaluminum compound of formula I (R is a 1-10C saturated hydrocarbon) (e.g. triethylaluminum), (C) an organosilicon compound of formula II (R<1>-R<3> each is a 1-20C hydrocarbon, etc.) (e.g cyclohexylmethyl dimethoxysilane) and (D) a Lewis acid containing at least one halogen atom (e.g. aluminum trichloride), 0.1-100g(per g of the component A) of an alpha-olefin is prepolymerized.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for prepolymerizing .alpha.-olefins. More specifically, after the prepolymerization of the present invention, an α-olefin, particularly an α-olefin having 3 or more carbon atoms is used.
The present invention relates to a prepolymerization method which makes it possible to obtain a polymer having high stereoregularity in a high yield when olefin is polymerized.

[0002]

2. Description of the Related Art Ziegler-Natta type catalysts have been well known as α-olefin polymerization catalysts, and methods for improving the polymerization activity and stereoregularity are known. Among them, titanium, magnesium,
Further, by using halogen and halogen as essential components, the polymerization activity has been greatly improved. However, when propylene or the like is polymerized by using this catalyst, the activity is very high, but the practical value is lost because the obtained polymer has extremely low stereoregularity.

Therefore, there has been proposed a method of improving stereoregularity by incorporating an electron donor such as various esters and ethers into titanium components containing titanium, magnesium and halogen. Furthermore, in addition to such a titanium component and an organoaluminum component, an electron donor such as an ester, an ether, an amine, an organosilicon compound, etc. is further added in the polymerization for further improvement. However, although the stereoregularity of the polymer obtained by such a method has been considerably improved, on the other hand, it has a drawback that the polymerization activity is remarkably lowered by adding a large amount of an electron donor. It was

On the other hand, by preliminarily polymerizing a small amount of propylene with such a catalyst system before the main polymerization, not only the particle properties and the polymerization activity of the resulting polymer are improved but also the stereoregularity of the polymer is obtained. Is also known to be improved (JP-A-55-75409). However, even with such a method, the polymerization activity and stereoregularity have not yet reached a level that can be satisfied at the same time.

[0005]

As described above, there has been a demand for a method for producing a highly stereoregular polyolefin with a higher polymerization activity.

[0006]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by carrying out a specific prepolymerization,
The present invention has been completed.

That is, the present invention provides an organoaluminum compound represented by [A] titanium compound [B] general formula R ₃ Al [I] (wherein R is a saturated hydrocarbon group having 1 to 10 carbon atoms). [C] General formula R ¹ R ² Si (OR ³ ) ₂ [II] (wherein R ¹ , R ² and R ³ are the same or different hydrocarbon groups having 1 to 20 carbon atoms and R ¹ And R ²
At least one of them has an atom directly connected to the silicon atom,
It is a chain hydrocarbon group which is a tertiary carbon or a cyclic hydrocarbon group which is a secondary carbon. In the presence of a Lewis acid compound having at least one halogen atom, α-olefin is polymerized in an amount of 0.1 to 100 g per 1 g of the titanium compound. is there.

As the titanium compound [A] used in the prepolymerization method of the present invention, compounds known to be used for the polymerization of α-olefins can be adopted without any limitation. Particularly, a titanium compound containing titanium, magnesium and halogen as components and having high catalytic activity is preferable. Such a titanium compound having a high catalytic activity is one in which various halogen compounds, particularly titanium tetrachloride, are supported on various magnesium compounds. As a method for producing this catalyst, a known method can be adopted without any limitation. For example, a method of co-milling titanium tetrachloride with a magnesium compound such as magnesium chloride, a method of co-milling a titanium halide and a magnesium compound in the presence of an electron donor such as alcohol, ether, ester, ketone or aldehyde, or , A method of bringing a titanium halide, a magnesium compound and an electron donor into contact with each other in a solvent. A method for producing such a titanium compound is described in, for example, JP-A-56-155206 and JP-A-5-155206.
6-136806, 57-34103, 58-87.
06, 58-83006, 58-138708, 58-183709, 59-206408, 59-.
219311, the same 60-81208, the same 60-8120
9, the same 60-186508, the same 60-192708, the same 61-211309, the same 61-271304, the same 62-.
15209, 62-11706, 62-7270.
2, the method shown in the same 62-104810 etc. is adopted.

Next, as the organoaluminum compound [B], the compound represented by the general formula [I] can be used without any limitation. In the general formula [I], R is a saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the saturated hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, t-
Butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group,
Examples thereof include chain alkyl groups such as decyl group, cyclopentyl group, cyclohexyl group and cyclic alkyl groups.

Specific examples of the organoaluminum compound [B] that can be preferably used in the present invention include, for example:
Trimethyl aluminum, triethyl aluminum, tri-n propyl aluminum, tri-n butyl aluminum, tri-i butyl aluminum, tri-n hexyl aluminum, tri-n octyl aluminum, tri-
Trialkylaluminums such as n-decylaluminum can be used. Of these, triethylaluminum is most preferable.

The amount of the organoaluminum compound used in the prepolymerization is not particularly limited, but it is generally preferable that Al / Ti (molar ratio) is 1 to 100 with respect to Ti atoms in the titanium compound, Further, it is preferably 3 to 10.

Further, as the organosilicon compound [C], the compound represented by the general formula [II] can be used without any limitation. In the general formula, the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ , R ² and R ³ is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group. , Pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, and cyclopentyl group, alkyl group-substituted cyclopentyl group, cyclohexyl group, alkyl group-substituted cyclohexyl group, t-
Examples thereof include a butyl group and a t-amyl group.

In the above general formula [II], at least one of R ¹ and R ² is a chain hydrocarbon group in which the atom directly bonded to the silicon atom is a tertiary carbon, or is a secondary carbon. It is a cyclic hydrocarbon group. Here, examples of the chain hydrocarbon group in which the atom directly bonded to the silicon atom is a tertiary carbon include a t-butyl group and a t-amyl group. Further, as the cyclic hydrocarbon group in which the atom directly bonded to the silicon atom is secondary carbon, a cyclopentyl group, a 2-methylcyclopentyl group, a 3-methylcyclopentyl group, a 2-ethylcyclopentyl group, a 2-n-butylcyclopentyl group, 2,3-
Dimethylcyclopentyl group, 2,4-dimethylcyclopentyl group, 2,5-dimethylcyclopentyl group, 2,3
-Diethylcyclopentyl group, 2,3,4-trimethylcyclopentyl group, 2,3,5-trimethylcyclopentyl group, 2,3,4-triethylcyclopentyl group, tetramethylcyclopentyl group, tetraethylcyclopentyl group, cyclohexyl group, 2-methyl Cyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, 2-ethylcyclohexyl group, 2,3-dimethylcyclohexyl group, 2,4-dimethylcyclohexyl group, 2,5-dimethylcyclohexyl group, 2,6-dimethyl Cyclohexyl group, 2,3-diethylcyclohexyl group, 2,3,4-trimethylcyclohexyl group,
2,3,5-trimethylcyclohexyl group, 2,3,6
-Trimethylcyclohexyl group, 2,4,5-trimethylcyclohexyl group, 2,4,6-trimethylcyclohexyl group, 2,3,4-triethylcyclohexyl group,
2,3,4,5-tetramethylcyclohexyl group, 2,
3,4,6-tetramethylcyclohexyl group, 2,3
5,6-tetramethylcyclohexyl group, 2,3,4
Examples include 5-tetraethylcyclohexyl group, pentamethylcyclohexyl group, pentaethylcyclohexyl group and the like.

Examples of the organosilicon compound preferably used in the present invention are as follows. For example, the t-
Butyldimethoxysilane, di-t-amyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, di (2-methylcyclopentyl) dimethoxysilane, di (3-methylcyclopentyl) dimethoxysilane, di (2-ethylcyclopentyl) dimethoxysilane, Di (2,3-dimethylcyclopentyl) dimethoxysilane, di (2,4-dimethylcyclopentyl) dimethoxysilane, di (2,5-dimethylcyclopentyl) dimethoxysilane, di (2,3-diethylcyclopentyl) dimethoxysilane, di ( 2, 3,
4-trimethylcyclopentyl) dimethoxysilane, di (2,3,5-trimethylcyclopentyl) dimethoxysilane, di (2,3,4-triethylcyclopentyl)
Dimethoxysilane, di (tetramethylcyclopentyl)
Dimethoxysilane, di (tetraethylcyclopentyl)
Dimethoxysilane, di (2-methylcyclohexyl) dimethoxysilane, di (3-methylcyclohexyl) dimethoxysilane, di (4-methylcyclohexyl) dimethoxysilane, di (2-ethylcyclohexyl) dimethoxysilane, di (2,3-dimethyl) Cyclohexyl) dimethoxysilane, di (2,4-dimethylcyclohexyl)
Dimethoxysilane, di (2,5-dimethylcyclohexyl) dimethoxysilane, di (2,6-dimethylcyclohexyl) dimethoxysilane, di (2,3-diethylcyclohexyl) dimethoxysilane, di (2,3,4-trimethylcyclohexyl) Dimethoxysilane, di (2,
3,5-trimethylcyclohexyl) dimethoxysilane, di (2,3,6-trimethylcyclohexyl) dimethoxysilane, di (2,4,5-trimethylcyclohexyl) dimethoxysilane, di (2,4,6-trimethylcyclohexyl) dimethoxy Silane, di (2,3,4-
Triethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetramethylcyclohexyl) dimethoxysilane, di (2,3,5,6-)
Tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetraethylcyclohexyl) dimethoxysilane, di (pentamethylcyclohexyl) dimethoxysilane, di (pentaethylcyclohexyl) dimethoxysilane, t-butylmethyldimethoxysilane, t
-Butylethyldimethoxysilane, t-amylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylisobutyldimethoxysilane and the like can be mentioned.

The amount of the organosilicon compound used in the prepolymerization is not particularly limited, but is generally 0.1 in terms of Si / Ti (molar ratio) with respect to Ti atoms in the titanium compound.
It is preferably -100, and more preferably 0.5-10.

As the component [D] used in the prepolymerization of the present invention, a known compound can be used without any limitation as long as it is a Lewis acid compound having at least one halogen atom. Specific examples of the component [D] that can be preferably used in the present invention include the following compounds. For example, aluminum trichloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, diethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, diisobutyl aluminum chloride, di n-
Propyl aluminum chloride, ethyl aluminum dibromide, ethyl aluminum diiodide, isobutyl aluminum dichloride, isobutyl aluminum dibromide, isobutylaluminium diiodide and other halogen atom-containing aluminum compounds, titanium tetrachloride and other halogen atom-containing titanium compounds, Examples thereof include halogen atom-containing tin compounds such as tin tetrachloride, and halogen atom-containing zinc compounds such as zinc chloride.

Among these Lewis acid compounds, the following formula [III] AlR ⁴ _n X _3-n [III] (wherein R ⁴ is a saturated hydrocarbon group having 1 to 10 carbon atoms, X is a halogen atom) And n is a number from 0 to 2.5.), The halogen atom-containing aluminum compound has a high polymerization ratio to obtain a polyolefin, and the polyolefin particles obtained by the polymerization have a high bulk density. Since it is easy to handle, it can be preferably used in the present invention. In the above formula [III], as the saturated hydrocarbon group having 1 to 10 carbon atoms, the groups described for the organoaluminum compound [B] can be directly used. As the halogen atom represented by X, chlorine, bromine, and iodine atoms can be used, but in general, chlorine atom is preferable.

The amount of the Lewis acid compound used in the prepolymerization is not particularly limited, but it is generally preferable that the molar ratio is 0.1 to 100 with respect to the Ti atom in the titanium compound. It is preferably 0.5 to 10.

In the present invention, in addition to the above titanium compound [A], organoaluminum compound [B], organosilicon compound [C] and Lewis acid compound [D] having at least one halogen atom, the following general formula [IV] R'-I [IV] (wherein R'is an iodine atom or a hydrocarbon group.)
It is preferable to use the iodine compound [E] represented by the above because the stereoregularity of the obtained polymer is further enhanced.
In the above general formula [IV], R'is a hydrocarbon group such as an alkyl group, an alkenyl group, an alkynyl group or an aryl group. Specific examples of the iodine compound that can be preferably used in the present invention include iodine, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, iodobenzene, p-toluene iodide and the like. Of these, methyl iodide and ethyl iodide are preferable.

The amount of the iodine compound used in the prepolymerization is not particularly limited, but in general, the I / Ti (molar ratio) is preferably 0.1 to 100 with respect to the Ti atom in the titanium compound, and further 0. It is preferably from 0.5 to 50.

The above-mentioned components used in the prepolymerization may be added one after another, or may be mixed together. The order of addition in the case of sequential addition is not particularly limited.

The amount of α-olefin polymerized in the preliminary polymerization is
0.1 to 100 g, preferably 1 per 1 g of titanium compound
The range is from 100 to 100 g, and industrially, the range is from 2 to 50 g. Examples of the α-olefin used in the prepolymerization include linear α-olefins such as ethylene, propylene, 1-butene, 1-pentene and 1-hexene. Further, it is possible to use two or more kinds of the above-mentioned α-olefins at the same time, and it is also possible to carry out preliminary polymerization in stages and use different α-olefins in each stage. Considering the improvement of the stereoregularity of the obtained polymer, it is preferable to use 90 mol% or more of a specific kind of α-olefin. It is also possible to make hydrogen coexist by prepolymerization.

For the prepolymerization, it is usually preferable to apply slurry polymerization, and a saturated aliphatic hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene is used alone or a mixed solvent thereof is used as a solvent. Can be used. The prepolymerization temperature is generally −20 to 100 ° C., particularly preferably 0 to 60 ° C.,
When the prepolymerization is carried out in multiple steps, it may be carried out under different temperature conditions in each step. The prepolymerization time may be appropriately determined according to the prepolymerization temperature and the amount of polymerization in the prepolymerization, and the pressure in the prepolymerization is not limited, but in the case of slurry polymerization, it is generally from atmospheric pressure to 5 kg / cm ^2. It is a degree. The prepolymerization may be carried out batchwise, semi-batchly or continuously. At the end of the prepolymerization, it is preferable to wash saturated aliphatic hydrocarbons or aromatic hydrocarbons such as hexane, heptane, cyclohexane, benzene, and toluene alone or with a mixed solvent, and the washing frequency is usually 5 to 6 times. Is preferred.

After the preliminary polymerization of the present invention, the main polymerization of α-olefin is carried out in the presence of the titanium-containing polyolefin obtained by the preliminary polymerization and the organoaluminum compound.
The polymerization conditions in the main polymerization after the preliminary polymerization in the present invention are not particularly limited as long as the effects of the present invention are observed, and known methods can be adopted. Generally, the following conditions are preferable.

As the organoaluminum compound used in the main polymerization, known compounds that can be used in the polymerization of α-olefin are used without any limitation. For example, trimethyl aluminum, triethyl aluminum, tri-n-propyl aluminum, tri-n-butyl aluminum,
Tri-alkyl aluminums such as tri-iso-butyl aluminum, tri-n-hexyl aluminum, tri-n-octyl aluminum, and tri-n-decyl aluminum; diethyl aluminum monohalides such as diethyl aluminum monochloride; methyl aluminum sesquichloride And alkylaluminum halides such as ethylaluminum sesquichloride and ethylaluminum dichloride. Further, alkoxyaluminums such as monoethoxydiethylaluminum and diethoxymonoethylaluminum can be used. Of these, triethylaluminum is most preferable. Although the amount of the organoaluminum compound used is not particularly limited, it is generally 10 in terms of Al / Ti (molar ratio) with respect to Ti atoms in the titanium-containing polyolefin obtained by prepolymerization.
Is preferably from 1000 to 1000, more preferably from 20 to 50.
It is preferably 0.

Further, in order to control the stereoregularity of the α-olefin having 3 or more carbon atoms, electrons such as ethers, amines, amides, sulfur-containing compounds, nitriles, carboxylic acids, acid amides, acid anhydrides, acid esters, organosilicon compounds, etc. The donor can coexist. Of these, organosilicon compounds are preferable. As such an organic silicon compound, the same compounds as those described in the above-mentioned prepolymerization can be used, and dimethyldimethoxysilane, diethyldimethoxysilane, dipropyldimethoxysilane, divinyldimethoxysilane, diallyldimethoxysilane, diphenyldimethoxy. Silane, methylphenyldimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane,
Pentyltriethoxysilane, isopropyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, allyltriethoxysilane and the like can be mentioned. It is also possible to use a plurality of the above compounds at the same time.

The amount of the organosilicon compound used in the main polymerization is not particularly limited, but it is generally 0.1 to 1000 in terms of Si / Ti (molar ratio) with respect to Ti atoms in the titanium-containing polyolefin. It is preferable that it is 1 to 100. The order of adding the components used in the main polymerization is not particularly limited. The organoaluminum compound and the organosilicon compound may be mixed and used.

The polymerization temperature of the main polymerization is 20 to 200 ° C., preferably 50 to 150 ° C., and hydrogen can be allowed to coexist as a molecular weight modifier. Further, the polymerization can be applied to slurry polymerization, solventless polymerization, and gas phase polymerization, and a batch system,
Either a semi-batch method or a continuous method may be used, and the polymerization may be carried out in two or more stages under different conditions.

The α-olefin to be polymerized is ethylene, propylene, 1-butene, 1-pentene, 1-hexene or the like. Homopolymerization of these α-olefins,
Alternatively, random copolymerization and block copolymerization in which two or more kinds are mixed and used can be performed. For example, α-olefin homopolymerization such as ethylene homopolymerization, propylene homopolymerization, and 1-butene homopolymerization; ethylene-propylene random copolymerization, propylene-1-butene random copolymerization, ethylene-1-butene random copolymerization, ethylene-
Α-Olefin random copolymers such as propylene-1-butene terpolymer; and block copolymers in which propylene homopolymerization is carried out in the first stage and propylene and ethylene are copolymerized in the second stage. And so on.

[0030]

By adopting the prepolymerization method of the present invention, a highly stereoregular polyolefin can be obtained in an extremely high yield.

[0031]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The measuring method used in the following examples will be described.

(1) p-Xylene Soluble Content 1 g of the polymer was added to 100 cc of p-xylene and the temperature was raised to 120 ° C. with stirring, and then stirring was continued for another 30 minutes to completely dissolve the polymer. , P-xylene solution was left at 23 ° C. for 24 hours. The precipitate was filtered off and the p-xylene solution was completely concentrated to obtain a soluble component.

Room temperature p-xylene solubles (%) = (p-xylene solubles
It is represented by (g) / polymer 1 g) × 100.

(2) Melt index (hereinafter, abbreviated as MI) According to ASTM D-790.

(3) Bulk Specific Gravity Based on JIS K6721.

Example 1 [Preparation of titanium compound] The titanium component was prepared according to the method of Example 1 in JP-A-58-83006. That is, 0.95 g of anhydrous magnesium chloride (10 mm
ol), 10 ml of decane, and 4.7 ml (30 mmol) of 2-ethylhexyl alcohol were heated and stirred at 125 ° C. for 2 hours. 0.55 g of phthalic anhydride in this solution
(6.75 mmol) was added, and the mixture was stirred and mixed at 125 ° C. for 1 hour to obtain a uniform solution. After cooling to room temperature, 40 ml of titanium tetrachloride (0.
(36 mol) was added dropwise over 1 hour.
Then, the temperature of this mixed solution was raised to 110 ° C. over 2 hours, and when it reached 110 ° C., 0.54 ml of diisobutyl phthalate was added, and the mixture was kept under stirring at 110 ° C. for 2 hours. After the completion of the reaction for 2 hours, the solid part was collected by filtration, resuspended in 200 ml of TiCl ₄ , and then the reaction was carried out again at 110 ° C. for 2 hours. After the reaction is completed, the solid part is collected again by hot filtration,
It was sufficiently washed with decane and hexane until no free titanium compound was detected in the washing liquid. The composition of the solid Ti catalyst is 2.1% by weight of titanium, 57% by weight of chlorine, 18.0% of magnesium, and 21.9% of diisobutyl phthalate.
% By weight.

[Preliminary Polymerization] N ₂ -substituted internal volume 1 L
Purified n-hexane (200 ml), triethylaluminum (50 mmol), cyclohexylmethyldimethoxysilane (10 mmol), ethylaluminum dichloride (50 mmol), and a solid Ti catalyst component (5 mmol) in terms of Ti atom were charged into the autoclave, and propylene was added to 1 g of the solid Ti catalyst component. It was continuously introduced into the autoclave for 30 minutes so that the amount became 3 g. The temperature during this period was kept at 15 ° C. The reaction was stopped after 30 minutes, and the inside of the autoclave was sufficiently replaced with N ₂ . The solid portion of the obtained slurry was washed with purified n-hexane four times to obtain titanium-containing polypropylene. As a result of the analysis, 2.1 g of propylene was polymerized with respect to 1 g of the solid Ti catalyst component.

[Main Polymerization] 1.0 L of propylene was charged into an N ₂ -substituted autoclave having an internal volume of 2 L, 1.1 mmol of triethylaluminum, 0.11 mmol of cyclohexylmethyldimethoxysilane, and further hydrogen gas in a gas phase. After charging so that the gas concentration would be 3.2 mol%, the internal temperature of the autoclave was raised to 65 ° C., and the titanium-containing polypropylene was treated as Ti atoms at 4.38 × 10 ^−3.
mmol charged. Then, set the internal temperature of the autoclave to 70
The temperature was raised to ° C and polymerization was carried out for 1 hour. After completion of the polymerization, unreacted propylene was purged to obtain a white granular polymer. The obtained polymer was vacuum dried at 70 ° C. for 1 hour. The results are shown in Table 1.

Examples 2 to 4 Instead of cyclohexylmethyldimethoxysilane used in the prepolymerization and polymerization of Example 1, dicyclopentyldimethoxysilane (Example 2), t-butylethyldimethoxysilane (Example 3), dicyclopentyldimethoxysilane (Example 3), The same operation as in Example 1 was performed except that t-butyldimethoxysilane (Example 4) was used. The results are shown in Table 1.

Examples 5 to 8 Instead of the ethylaluminum dichloride used in the prepolymerization of Example 1, ethylaluminum sesquichloride (Example 5), diethylaluminum chloride (Example 6) and titanium tetrachloride (Example 7). The same operation as in Example 1 was performed except that tin tetrachloride (Example 8) was used. The results are shown in Table 1.

Example 9 In the prepolymerization of Example 1, 50 mm of ethyl iodide was added.
The same operation as in Example 1 was performed except that ol was added. The results are shown in Table 1.

Examples 10 to 11 The amount of ethylaluminum dichloride used in the prepolymerization of Example 1 was 25 mmol (Example 10), 10 mmo.
The same operation as in Example 1 was performed except that 1 (Example 11) was used. The results are shown in Table 1. Examples 12 to 13 The amount of cyclohexylmethyldimethoxysilane used in the prepolymerization of Example 1 was 25 mmol (Example 12), 5 m.
The same operation as in Example 1 was performed except that the amount was mol (Example 13). The results are shown in Table 1.

Comparative Examples 1 and 2 In the prepolymerization of Example 1, no ethyl aluminum dichloride was used (Comparative Example 1) and cyclohexylmethyldimethoxysilane was not used (Comparative Example 2). The same operation as in 1 was performed. The results are shown in Table 1.
It was shown to.

Comparative Examples 3 to 5 In the prepolymerization of Example 1, ethyl silicate (Comparative Example 3) was used instead of cyclohexylmethyldimethoxysilane.
The same operation as in Example 1 was performed except that ethyltriethoxysilane (Comparative Example 4) and diphenyldimethoxysilane (Comparative Example 5) were used. The results are shown in Table 1.

Comparative Example 6 In the prepolymerization of Example 1, the same operation as in Example 1 was performed except that triethylaluminum was not used.
The results are shown in Table 1.

Example 14 The same procedure as in Example 1 was carried out except that ethylene gas was charged so that the gas concentration in the gas phase was 0.8 mol% and random copolymerization of propylene and ethylene was carried out. The same operation as in Example 1 was performed. The results are shown in Table 1.

Example 15 In an autoclave having an internal volume of 300 L, which had been subjected to N ₂ substitution,
100 kg of propylene was charged, 175 mmol of triethylaluminum, 88 mmol of cyclohexylmethyldimethoxysilane, and hydrogen gas were further charged so that the gas concentration in the gas phase was 7.5 mol%, and then the internal temperature of the autoclave was raised to 65 ° C. After heating, 0.877 mmol of titanium-containing polypropylene was charged as Ti atom. Then, the internal temperature of the autoclave was raised to 70 ° C. and polymerization was carried out for 1 hour. After 1 hour, unreacted propylene was purged to obtain a white granular polymer. Polymer 15k obtained thereafter
g was transferred to a gas phase polymerization tank having an internal volume of 800 L, a propylene-ethylene mixed gas having an ethylene gas concentration of 35 mol% was supplied, and polymerization was carried out at 70 ° C. for 2 hours. Unreacted monomer was purged to obtain a white granular block copolymer. The ethylene content in the polymer was 4.8 wt%. The results are shown in Table 1.

[0048]

[Table 1]

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[Procedure amendment]

[Submission date] November 30, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Added

[Correction content]

[Brief description of drawings]

FIG. 1 is a flow chart showing a typical polymerization procedure in the present invention.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Added

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. An organoaluminum compound represented by [A] titanium compound [B] general formula R ₃ Al [I] (wherein R is a saturated hydrocarbon group having 1 to 10 carbon atoms) [C] general wherein ^{R 1 R 2 Si (oR 3} ) 2 [II] (wherein, R ^1, R ² and R ³ is a hydrocarbon group having 1 to 20 carbon atoms in each same or different, R ¹ and R ²
At least one of them has an atom directly connected to the silicon atom,
It is a chain hydrocarbon group which is a tertiary carbon or a cyclic hydrocarbon group which is a secondary carbon. [D] An organoolefin prepolymerization method characterized by polymerizing 0.1 to 100 g of an α-olefin per 1 g of a titanium compound in the presence of a Lewis acid compound having at least one halogen atom.