JPH0496907A - Prepolymerization of olefin - Google Patents

Abstract

PURPOSE:To prepare a polymer, excellent in transparency, rigidity and heat resistance, high in stereoregularity, etc., and suitable for injection moldings, films, etc., by subjecting an olefin to a multi-stage prepolymerization reaction by adding a catalyst containing different organic silicon compounds in the every polymerization stages. CONSTITUTION:(D) An olefin such as propylene is prepolymerized in a solvent such as hexane in the presence of (A) a titanium compound such as titanium tetrachloride carried on magnesium chloride, (B) an organic aluminum compound such as triethyl aluminum and (C) an organic silicon compound of formula I (R, R' are hydrocarbon; (n) is 1-3) for providing the objective polymer, while the component C is changed for each stage and is used preferably two to five times repeatedly, e.g. into a compound of formula II (R1 is H, alkyl; R<2>, R<3> are alkyl) or III (R<4> is alicyclic hydrocarbon or aromatic hydrocarbon) at the first polymerization stage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides a pre-grI! Regarding the matching method.

(Prior Art and Problems to be Solved by the Invention) Polypropylene is widely used as a resin with excellent mechanical properties, moldability, and chemical stability.

However, in terms of transparency, it is generally inferior to resins such as polystyrene and polyvinyl chloride due to its high crystallinity.

Several proposals have been made in attempts to improve the transparency of polypropylene. For example, by adding nucleating agents such as sorbitol derivatives, sodium salts or potassium salts of aromatic carboxylic acids to polypropylene, the spherulites of molded products are made small and uniform, thereby improving the transparency of molded products. It is known (Japanese Patent Application Laid-Open No. 58-80392, Japanese Patent Application Laid-Open No. 55-12460). However, during molding, these organic nucleating agents
In particular, there have been problems in that during molding of sheets and biaxially stretched films, the resin bleeds out, causing roll stains, and that odor is generated during processing. Furthermore, aromatic carboxylic acid salts have the problem of coloring the resin due to hydrolysis or reaction with other additives.

On the other hand, a method is known in which the transparency of polypropylene is improved by prepolymerizing a small amount of branched α-olefin such as 3-methylbutene-1 using a conventional stereoregular catalyst (JP-A-63-69809). , Japanese Patent Publication No. 62-17
Publication No. 38). According to this method, there is no fear of bleed-out and the effect of improving the transparency of polypropylene can be obtained.

However, when polypropylene is used for applications such as films, this level of transparency is not fully satisfactory, and even better transparency is required.

(Means for Solving the Problems) In view of the above problems, the present inventors conducted intensive research and found that the above objects could be achieved by performing a specific prepolymerization. It's arrived.

That is, the present invention comprises the following components A, B and OA, titanium compound B, organoaluminum compound C6 general formula CI) R-3i(OR')4-CI
) Prepolymerization of an olefin is carried out in multiple stages in the presence of an organosilicon compound represented by 1, a different organosilicon compound is used in each prepolymerization step, and at least one of the prepolymerization steps has the following formula (A): CH2=C)I-C-R” [:
A ] or the following formula CB] CH,=CH-R' CB, ] This is a method for prepolymerizing olefins, which is characterized by polymerizing an unsaturated compound represented by the following formula.

Titanium compound (A) used in the prepolymerization method of the present invention
Any compound known to be used in the polymerization of olefins may be employed without any restriction. In particular, titanium compounds with high catalytic activity containing titanium, magnesium, and halogen are suitable. Such titanium compounds with high catalytic activity include titanium halides, particularly titanium tetrachloride, supported on various magnesium compounds.

For the production of this catalyst, any known method may be employed without any restriction. For example, JP-A-56-155206, JP-A-56-155206;
136806, 57-34103, 5B-870
6, 5B-83006, 58-138708, 58-183709, 59-206408, 59-
219311, 60-81208, 60-812
09, 60-186508, 60-192708
, 61-211309, 61271304, 62
-15209, 62-11706, 62-7270
2, the method shown in 6'2-104810 etc. is adopted.

Specifically, for example, titanium tetrachloride is co-milled with a magnesium compound such as magnesium chloride, titanium tetrachloride and magnesium in the presence of an electron donor such as an alcohol, ether, ester, ketone or aldehyde. Examples include a method of co-milling with a compound, or a method of bringing a titanium halide, a magnesium compound, and an electron donor into contact with each other in a solvent.

Next, as the organoaluminum compound (B), any compound known to be used in the polymerization of olefins can be used without any restriction. For example, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-n-decylaluminum,
Trialkyl aluminums such as tri-n hexyl aluminum, tri-n decyl aluminum, tri-n decyl aluminum; diethylaluminum monohalides such as diethyl aluminum monochloride; alkyl aluminum halides such as methyl aluminum sesquichloride, ethyl aluminum dichloride, and ethyl aluminum dichloride; Examples include. In addition, alkoxyaluminums such as monoethoxydiethylaluminum and jetoxymonoethylaluminum can be used. Among them, triethylaluminum is most preferred. The amount of organoaluminum compound used in each prepolymerization step is Aj! relative to the Ti atom in the titanium compound. /T
i (molar ratio) is 1 to 100, preferably 2 to 20.

Further, as the organosilicon compound (C), a compound represented by the above general formula [the same] may be used without any limitation. General formula C1
R and R' in E are hydrocarbon groups such as an alkyl group, an alkenyl group, an alkynyl group, and an aryl group. Examples of organosilicon compounds preferably used in the present invention are as follows. For example, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyljethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane,
Phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, ethyl silicate, 6-driethoxysilyl 2-
Such as norbornene.

The amount of the organosilicon compound used in each prepolymerization step is from 0.1 to 100, preferably from 0.5 to 10, in Si/Ti (molar ratio) relative to the Ti atoms in the titanium compound.

In the present invention, the above titanium compound (A), organoaluminum compound (B) and organosilicon compound (C)
In addition, it is preferable to use an iodine compound (D) represented by the following general formula (II) R'-1 (II) because the resulting polyolefin has high rigidity and heat resistance.

In the general formula (If), R' is a hydrocarbon group such as an alkyl group, an alkenyl group, an alkynyl group, or an aryl group. Specific examples of iodine compounds that can be suitably used in the present invention are as follows. Examples include iodine, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, iodobenzene, p-toluene iodide, and the like. Among them, methyl iodide and ethyl iodide are preferred. The amount of the iodine compound used in each prepolymerization step is 0.1 to 100 I/Ti (mole ratio) based on the titanium atom in the titanium compound.
, preferably 0.5 to 50.

In the present invention, prepolymerization is carried out in multiple stages, and different types of organosilicon compounds are used in each prepolymerization stage.

In the present invention, carrying out prepolymerization in multiple stages means the above [
Prepolymerize the olefin in the presence of each component of A), CB), (C) and CD) used if necessary, and the obtained titanium-containing polyolefin and the above CB), (C)
It also means repeatedly carrying out prepolymerization of olefin in the presence of each component (D) used as necessary. Prepolymerization is preferably carried out 2 to 5 times. The above-mentioned components used in each prepolymerization may be added sequentially or may be mixed together.

A different type of organosilicon compound is used in each prepolymerization step. As the organosilicon compound, it is preferable to use a compound in which at least one of R and R' in the general formula (1) is a bulky hydrocarbon group, such as a phenyl group, a cyclohexyl group, or a norbornyl group. This method is preferable because a polyolefin with high properties can be obtained. The order of use of the organosilicon compounds used in each prepolymerization step is not particularly limited.

In the prepolymerization of the present invention, a specific unsaturated compound is polymerized in at least one of the above-mentioned prepolymerization steps. As the unsaturated compound, a compound represented by the following formula (A) or CB) is used.

CH2=CFl-C-R” [A
) CH2=CH-R' (B) Here, in the above formula (A), the alkyl groups represented by R', RZ and R3 are not particularly limited in number of carbon atoms, but the transparency of the polypropylene obtained In order to improve properties, it is preferable that the number of carbon atoms is 1 to 6.

Furthermore, in the above formula (B), the alicyclic hydrocarbon group represented by R4 may be either saturated or unsaturated (also,
Although the number of carbon atoms is not particularly limited, a six-membered ring is preferred from the viewpoint of transparency of the polypropylene obtained. Specifically, cyclohexyl group, 1-cyclohexene-1-
yl group, 2cyclohexen-1-yl group, 3-cyclohexen-1-yl group, 2-methyl-1-cyclohexen-1-yl group, 3-methyl-1-cyclohexen-1-yl group
yl group, 4-methyl-1-cyclohexen-1-yl group, 2-methyl-2-cyclohexen-1-yl group, 3-
Methyl-2-cyclohexen-1-yl group, 4-methyl-2-cyclohexen-niyl group, 2-methyl-3-yl group
Examples include cyclohexen-1-yl group, 3-methyl-3-cyclohexen-1-yl group, and 4-methyl-3-cyclohexen-1-yl group.

Further, in the above formula CB), the aromatic hydrocarbon group represented by R' may be an aryl group or an aralkyl group without any restriction. The aryl group preferably has 6 to 10 carbon atoms, and specifically includes phenyl group, 0-)lyl group, m-)lyl group, p-tolyl group, 2,3-xylyl group, 2, Examples include 4-xylyl group and 4-1-butylphunyl group. Further, the aralkyl group preferably has 7 to 11 carbon atoms, and specific examples thereof include hensyl group, phenethyl group, phenylpropyl group, and phenylbutyl group.

Specific examples of the unsaturated compounds represented by formulas (A) and l'B) are as follows. For example, 3-methyl-
1-butene, 3-methyl-1-pentene, vinylcyclohexane, 4-vinylcyclohexene-1, styrene,
0-methylstyrene, pt-butylstyrene, allylbenzene, 1-vinyl-2-methylcyclohexene-1
Among these, 3-methyl-1-butene, 3-methyl-1-pentenvinylcyclohexane, 0-methylstyrene, and pt-butylstyrene are particularly preferred because they have a large effect on improving the transparency of polypropylene. used.

It is also possible to use two or more types of the above unsaturated compounds at the same time. Furthermore, 10 parts by weight or less of α-olefin, such as ethylene, propylene, butene, 1-hexene, 4-methyl-1-pentene, etc., may be made to coexist with the above-mentioned unsaturated compound. Preliminary polymerization may also be carried out in the presence of hydrogen.

Among the multiple prepolymerization steps in the present invention, the olefins used in the prepolymerization steps other than the step using the above-mentioned unsaturated compound include ethylene, propylene, 1-
Butene, 1-hexene, 4-methyl-1-pentene, etc., and it is possible to use two or more types at the same time, but in order to improve stereoregularity, 90 mol% or more of one specific type of olefin is used. It is preferable.

The amount of polymerization carried out in each prepolymerization step is the titanium compound 1
0.1-1000g per g, preferably 0.5-500g
You can choose from the range of g. The ratio of polymerization amount in each stage is not particularly limited.

For each prepolymerization, it is usually preferable to apply slurry polymerization, and as a solvent, a saturated aliphatic hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene, toluene, etc. may be used alone, or a mixed solvent thereof may be used. I can do it. Each prepolymerization temperature is -20 to 100
C. Temperatures of 0 to 60.degree. C. are preferred, and each stage of the prepolymerization may also be carried out under different temperature conditions. The prepolymerization time may be appropriately determined depending on the prepolymerization temperature and the polymerization amount in the prepolymerization, and the pressure in the prepolymerization is not limited, but in the case of slurry polymerization, it is generally atmospheric pressure to 5 kg/ It is about d. Each prepolymerization may be carried out in batch, semi-batch or continuous manner. After each preliminary polymerization, it is preferable to wash with a saturated aliphatic hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene, toluene, etc. alone or with a mixed solvent, and the number of washings is usually 5 to 5. Preferably 6 times.

The polymerization conditions in the main polymerization after the preliminary polymerization according to the present invention are as follows:
As long as the effects of the present invention are recognized, the following conditions are generally preferred, although there are no particular limitations. Polymerization temperature is 20 to 200
C1 is preferably 50 to 150°C, and hydrogen can also be present as a molecular weight regulator. In addition, the polymerization can be applied to slurry polymerization, solventless polymerization, and gas phase polymerization, and may be any of the batch, semi-batch, and continuous methods.
Furthermore, the polymerization can be carried out in two or more stages under different conditions. The olefins to be polymerized include ethylene, propylene, butene-1, pentene-1, hexene-1,
4-methylpentene-1, etc., and these seven polymers
These can be used alone or in combination of two or more. When using two or more types of olefins, it is preferable to use 90 mol % or more of one specific type from the viewpoint of improving the stereoregularity of the resulting polyolefin. Furthermore, in order to control the stereoregularity of olefins having 3 or more carbon atoms, electron donors such as ethers, amines, amides, sulfur-containing compounds, nitriles, carboxylic acids, acid amides, acid anhydrides, acid esters, and organosilicon compounds are allowed to coexist. be able to. Among them, organosilicon compounds are preferred. As such an organosilicon compound, one selected at the time of the above-mentioned prepolymerization can be used.

(Effects) According to the prepolymerization method of the present invention, it is possible to obtain a polyolefin with much better transparency than the conventional method of simply prepolymerizing a branched α-olefin. Furthermore, the polyolefin obtained by the method of the present invention has high stereoregularity and excellent rigidity and heat resistance.

Therefore, the polyolefin obtained by the method of the present invention can be satisfactorily used not only as an injection molded product but also as a film.

(Example) The present invention will be explained below with reference to Examples and Comparative Examples.
The present invention is not limited to these examples.

The measurement method used in the following examples will be explained.

(1) Stereoregularity The stereoregularity evaluation method used in the present invention is as follows (a)
and (b).

(a) Add 1 g of p-xylene soluble polymer to 100 cc of p-xylene and raise the temperature to 120°C while stirring. After continuing stirring for an additional 30 minutes to completely dissolve the polymer, add the p-xylene solution. 2
It was left at 3°C for 24 hours. The precipitate was separated by filtration, and the p-xylene solution was completely concentrated to obtain the soluble content.

Room temperature p-xylene soluble content (%)=(p-xylene soluble content (g)/1 g of polymer)X100.

(b) ''' C-N M R pentad back A,
Macron+olecu by Zambelli et al.
les 6,925 (1973), that is, the fraction of isotactic bonding of five consecutive heptamers in a polymer molecular chain using IICNMR.

Measurements were made using JEOL G5X-270, with a pulse width of 9
0'' pulse interval was 15 seconds, and the total number of times was too many.The beep was attributed to Macro+*olecules, 8,
697 (1975).

(2) Melt index (hereinafter abbreviated as Ml) AST
Compliant with MD-790.

(3) Flexural modulus (hereinafter abbreviated as Fm) Japan Steel Works J
63.6+u+X12 by 120S/l type injection molding machine
．． A test piece of 7 mm x 0.31 nv was prepared and ASTM
: Performed according to D-790.

(4) Heat distortion temperature (hereinafter abbreviated as HDT) Japan Steel Works
63.6m+*X by J120SAII type injection molding machine
Create a test piece of 12.7 mm x 0.31 mm, and
STM: Performed according to D-648.

(5) Transparency (Haze value) 80. OX50. OXl, 0
(vw) 48 hours after forming into a JIS-6
Measured according to 714.

(6) Molecular weight distribution (hereinafter abbreviated as Mw/Mn)
The ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) was measured by GPC (gel permeation chromatography) method. Waters GPC -150°C
The reaction was carried out at 135°C using O-dichlorobenzene as a solvent.

(7) Crystallization temperature (hereinafter abbreviated as Tc) The sample was held at 230''C for 10 minutes and heated at a speed of -40°C/min for measurement using a Seiko Electronics Industry DSC-200.

(8) Melting point (hereinafter abbreviated as Tm) The sample was
The temperature was held at 0°C for 10 minutes, the temperature was lowered to 120°C, isothermal crystallization was performed at the same temperature for 10 minutes, and after cooling to 50°C, the temperature was raised at 10°C/min and measured.

Example 1 [Preparation of titanium compound] The titanium component was prepared according to the method of Example 1 of JP-A-58-83006. That is, 0.95 g (10 mmol) of anhydrous magnesium chloride, 10 sol% of decane, and 4. 2-ethylhexyl alcohol.
After heating and stirring 7 mj2 (30 m + * ol) at 125°C for 2 hours, 0.55 g of phthalic anhydride (3
, 75 m*ol) was added thereto, and stirring and mixing was further performed at 125°C for 1 hour to obtain a homogeneous solution. Titanium tetrachloride 40n+j2 kept at 120°C after cooling to room temperature
(0.36 sol) over 1 hour. After charging, the temperature of this mixed liquid was raised to 110°C over 2 hours, and when it reached 110°C, diisobutyl phthalate 0.54 + j2 (2,5*ol) was added.
was added, and the mixture was kept at the same temperature for 2 hours with stirring.

After the 2-hour reaction, the solid part was collected by filtration, and this solid part was resuspended in 200 ml of T1Cf4, and then heated at 110°C for 2 hours. The solid portion was collected by hot filtration and thoroughly washed with decane and hexane until no free titanium compound was detected in the preliminary solution. The solid Ti catalyst component prepared by the above production method was stored as a heptane slurry. The composition of the solid Ti catalyst component is 2.1% by weight of titanium and 57% by weight of chlorine.
% by weight, 18.0% by weight of magnesium, and 21.9% by weight of diisobutyl phthalate.

[Prepolymerization]

200 ml of purified hebutane, triethylaluminum 50IIIlO1 in a 11 autoclave with N2 substitution
After charging 10+wmol of diphenyldimethoxysilane, 50mmol of ethyl iodide, and 5mn+ol of solid Ti catalyst component in terms of T-4 atoms, propylene was added to the solid Ti catalyst component.
The catalyst component was continuously introduced into the reactor in an amount of 3 g per 1 g for 1 hour to carry out the first prepolymerization. Note that the temperature during this time was maintained at 15°C. After 1 hour, the introduction of propylene was stopped, and the inside of the reactor was sufficiently purged with N2. The solid portion of the resulting slurry was washed six times with purified hebutane.

Further, this solid component was charged into a 11 autoclave which had been replaced with N2, and 200 I1 of purified hebutane, 50 mmol of triethylaluminum, 10 haze mol of 6-triethoxysilyl 2-turbolenenene, and 5 mol of ethyl iodide were added.
After adding 0 mmol, 3-methyl 1-butene Log was charged and reacted for 3 hours to perform a second prepolymerization. Note that the temperature during this time was maintained at 15°C. 3-methyl-1
- The prepolymerized amount of butene is 0.000.
It was 9g. The solid portion of the resulting slurry was washed six times with purified hebutane.

[Overlapping]

In an autoclave with an internal capacity of 4002 that was subjected to N2 substitution,
Propylene 2001 was charged, triethylaluminum 274 mmol, diphenyldimethoxysilane 274
m5+ol plus hydrogen 2. After charging ONn, the internal temperature of the autoclave was raised to 65°C, and the solid Ti catalyst component obtained through the above prepolymerization step was converted into titanium atoms.
1 mmol was charged. Subsequently, the internal temperature of the autoclave was raised to 75°C, and propylene was polymerized for 3 hours. The polymerization pressure was 34 kg/+u+'', and the temperature during this time was maintained at 75°C, and the hydrogen concentration was maintained at 0.2-01% while checking with a gas chromatograph. After 3 hours, unreacted propylene was purged and the mixture turned white. A granular polymer was obtained.The yield of the polymer was 52 kg, and the activity at this time was 20.8.
00gpp/g-cat・3Hr. An antioxidant was added to the above polymer, thoroughly mixed, and then pelletized using a granulator. Table 1 shows the physical properties of the obtained polypropylene.

Example 2 In the first prepolymerization of Example 1, 6-driethoxysilyl-2-norbornene was used instead of diphenyldimethoxysilane, and in the second prepolymerization, 6-driethoxysilyl-2-norpolene was used instead of diphenyldimethoxysilane. The same operation as in Example 1 was performed except that diphenyldimethoxysilane was used instead of. The results are shown in Table 1.

Example 3 Heptane 20011I! was added to the solid Ti catalyst component obtained in the prepolymerization of Example 1! ,,triethylaluminum 5
0s+mol, phenyltriethoxysilane 10+uw
After adding ethyl iodide l□n+ol, propylene was again introduced into the reactor for 1 hour in an amount of 3 g per 1 g of the solid Ti catalyst component to carry out the third prepolymerization.

The obtained solid component was washed six times with purified hebutane. Polymerization was carried out in the same manner as in Example 1.

The results are shown in Table 1.

Example 4 In the first prepolymerization of Example 1, 3-methyl-1-butene was used instead of propylene, and in the second prepolymerization,
The same operation as in Example 1 was performed except that propylene was used instead of 3-methyl-1-butene. The results are shown in Table 1.

Example 5 The same operation as in Example 1 was carried out except that 3-methyl-1-butene was used instead of propylene in the first prepolymerization of Example 1. The results are shown in Table 1.

Example 6 In the preliminary polymerization of Example 1, the same operation as in Example 1 was performed except that ethyl iodide was not used. Table 1 shows the results.
It was shown to.

Example 7 [Preparation of titanium compound] The method for preparing a titanium compound is described in JP-A-62-104810.
This was carried out according to the method of Example 1 of the publication. That is, 100 g of aluminum trichloride (anhydrous) and 29 g of magnesium hydroxide were reacted while being ground in a vibration mill at 250° C. for 3 hours. After the heating was completed, the mixture was cooled in a nitrogen stream to obtain a solid product (1).

In a glass flask, 15mj of purified decane! , 2.5 g of solid product (1), n-butyl orthotitanate 8
．． 5 g of 2-ethyl-1-hexanol and 9.8 g of 2-ethyl-1-hexanol were mixed and heated to 130° C. for 1.5 hours while stirring to melt and form a uniform solution. The solution was brought to 70°C and P-
) After adding 1.8 g of ethyl ruylate and reacting for 1 hour,
While stirring, 26 g of silicon tetrachloride was added dropwise over 2 hours to precipitate a solid, and the mixture was further stirred at 70°C for 11 hours. The solid was separated from the solution and washed with purified hexane to yield solid product (II).

1,2-dichloroethane 3 to the total amount of the solid product (n)
0-! and titanium tetrachloride 30tal! Add 1.5 g of diisobutyl phthalate and heat to 100° while stirring.
After reacting at C for 2 hours, the liquid phase was removed by decantation at the same temperature, and 30 m
jl! , titanium tetrachloride 30mf.

Add 1.5 g of diisobutyl phthalate and add 1.5 g of diisobutyl phthalate while stirring.
After reacting with OO'C for 2 hours, the solid portion was collected by hot filtration, washed with purified hexane, and dried at 25°C under reduced pressure for 1 hour to obtain solid product (II).

The solid product (I) was spherical, had an average particle size of 15 μm, and had a very narrow particle size distribution.

This solid product Th (I[I) was used as a solid Ti catalyst component.

In addition, the compositional analysis results of the solid Ti catalyst component are Ti3,
0% by weight (hereinafter referred to as %), Cj256.2%, 117
．． 6%, Afl, 7%, diisobutyl phthalate 20,.
1%, butoxy group 1.1%, 2-ethylhexyloxy io, 2%, and ethyl p-toluate 0.1%.

The preliminary polymerization and main polymerization were carried out in the same manner as in Example 1. The results are shown in Table 1.

Example Day [Preparation of Titanium Compound] The titanium compound was prepared according to the method of Example 1 of JP-A-6111706. That is, 50 sjl. of purified butane, 50 nl of titanium tetrabutoxide, and 7.0 g of anhydrous magnesium chloride are added.

Thereafter, the temperature of the flask was raised to 90°C, and the magfusium chloride was completely dissolved over a period of 2 hours. Next, add 4 flasks.
Magnesium chloride,
A titanium tetrabutoxide complex was precipitated. This was washed with purified butane to obtain an off-white solid.

Nitrogen replacement 300/! In a glass Mitsuro flask (with thermometer and stirrer), add l of the precipitated solid obtained above.
50 mj of heptane slurry containing OG! introduced. Next, silicon tetrachloride 5.8+/! Heptane solution containing 2
Oysl was added over 30 minutes at room temperature, and the mixture was further reacted at 30°C for 45 minutes. The reaction was further carried out at 90°C for 1.5 hours, and after the reaction was completed, the reaction mixture was washed with purified hebutane. Then,
Heptane solution containing 1.5 diheptyl phthalate + aβ 5
(]+j2 was added and reacted at 5°C for 2 hours, then washed with purified hebutane, and further added with 25 mj of titanium tetrachloride.
! was added and reacted at 9°C for 2 hours. This was washed with purified butane to obtain a solid Ti catalyst component. The titanium content in the solid Ti catalyst component was 3.04% by weight. The preliminary polymerization and main polymerization were carried out in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example I In the preliminary polymerization of Example 1, the same operation as in Example 1 was performed except that the second preliminary polymerization was not performed. The results are shown in Table 1.

Comparative Example 2 Same as Example 1 except that 3-methyl-1-butene was used instead of propylene in the first prepolymerization of Example 1, and the second prepolymerization was not performed. performed the operation. The results are shown in Table 1.

Comparative Example 3 Example 1 except that propylene-1 was used instead of 3-methylbutene-1 in the second prepolymerization of Example 1.
The same operation was performed. The results are shown in Table 1.

Comparative Example 4 The same operation as in Example 1 was performed except that in the second prepolymerization of Example 1, diphenyljethoxysilane was used instead of 6-driethoxysilyl-2-norbornene. The results are shown in Table 1.

Examples 9 to 12 At the same stage of the prepolymerization in Example 1, 3-methyl-1-
The same operation as in Example 1 was performed except that the unsaturated compounds shown in Table 2 were used instead of butene. The results are shown in Table 2.

Examples 13 to 15 In the prepolymerization of Example 1, phenyltriethoxysilane, methyltriethoxysilane,
The same operation as in Example 1 was performed except that methylphenyldiethoxysilane was used. The results are shown in Table 3.

Procedural amendment November 22, 1990

Claims (1)

[Claims] (1) The following components A, B and C A, titanium compound B, organoaluminum compound C, general formula R_nSi(OR')_4_-_n [However,
R and R' are the same or different hydrocarbon groups, and n is an integer of 1 to 3. Prepolymerization of an olefin is carried out in multiple stages in the presence of an organosilicon compound represented by the following formula ▲ Numerical formula, chemical formula, There are tables, etc. ▼ [However, R^1 is a hydrogen atom or an alkyl group, and R^
2 and R^3 are the same or different alkyl groups. ] or the following formula CH_2=CH-R^4 [However, R^4 is an alicyclic hydrocarbon group or an aromatic hydrocarbon group. ] A method for prepolymerizing an olefin, which comprises polymerizing an unsaturated compound represented by the following.