JPH0128047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for producing highly stereoregular α-olefin polymers.

<Prior art> Generally, as a method for producing crystalline olefin polymers, a so-called Ziegler-Natsuta catalyst consisting of a transition metal compound of group ~ of the periodic table and a metal of group ~ or an organometallic compound is used. It is well known to do so. When producing α-olefin polymers such as propylene and butyne-1 industrially, catalysts in which titanium tetrachloride or titanium trichloride is supported on a titanium trichloride composition or a magnesium-containing halide carrier are used. . In the conventional production method, an amorphous polymer is produced as a by-product in addition to a highly stereoregular olefin polymer that has high industrial utility value. This amorphous polymer has little industrial utility value, and has a large adverse effect on mechanical properties when the olefin polymer is processed into films, fibers, and other processed products. In addition, the production of the amorphous polymer causes loss of raw material monomers, and at the same time requires production equipment for removing the amorphous polymer, which is an extremely large disadvantage from an industrial perspective.

Therefore, it would be a great advantage if such amorphous polymers were not produced at all, or if they were produced at all, but only to a very small extent. On the other hand, if catalyst residue remains in the olefin polymer, this catalyst residue causes various problems in terms of stability, processability, etc. of the olefin polymer, and equipment for removing and stabilizing the catalyst residue is required. This drawback is
If the catalytic activity expressed by the weight of the olefin polymer produced per unit weight increases, it can be improved, and equipment for removing the catalyst residue is no longer required, reducing the production cost necessary for producing the olefin polymer. is also possible. For these purposes, attempts have been made to improve various polymerization catalysts, one of which is a magnesium-containing supported catalyst.

An example of a supported magnesium-containing catalyst is a catalyst in which titanium tetrachloride is supported after activating commercially available anhydrous magnesium chloride (Japanese Patent Publication No. 47-41676).
Alternatively, there is a catalyst in which titanium tetrachloride is supported on a carrier obtained by treating magnesium chloride with an electron-donating compound (Japanese Patent Application Laid-open No. 72383/1983).
In addition, by reducing titanium tetrachloride with an organomagnesium compound, a catalyst in which titanium trichloride is supported on a magnesium chloride carrier (Japanese Unexamined Patent Publication No. 46-4393), or a Grignard compound can be converted into a catalyst with gaseous HCl.
Catalyst in which titanium tetrachloride is supported on a magnesium chloride carrier obtained by reaction with (Japanese Patent Publication No. 47-41676)
There are also such things.

However, although these supported catalysts are very useful for the polymerization of ethylene, they produce a large amount of amorphous polymer as a by-product in the polymerization of propylene, etc., and have very low utility value.

Examples of supported catalysts for polymerizing α-olefins such as propylene include a method of co-pulverizing magnesium chloride, an inert solid organic substance, and a titanium tetrachloride-ester complex (Japanese Unexamined Patent Publication No. 1986-86482), magnesium chloride, a silicon compound, A method of co-pulverizing ester and then reacting it with titanium tetrachloride (Special Publication No. 52-36786)
(Japanese Unexamined Patent Publication No. 1989-1997), a method of reacting a halogen-free magnesium compound containing an alkoxy group or an aryloxy group with an electron donor and a titanium compound
-2580), or a method in which titanium tetrachloride is supported after treating magnesium chloride with alcohol, ester, aluminum halide compound (silicon halide compound), etc.
-28189, Japanese Unexamined Patent Publication No. 51-92885). The polymerization activity and stereoregularity of the catalysts produced by these methods are low, and the catalysts are unsatisfactory for industrial use in the stereoregular polymerization of α-olefins.
Furthermore, a pulverization step is often essential for catalyst production.

<Problems to be Solved by the Invention> The present inventors have conducted intensive studies in order to produce a catalyst that can obtain an α-olefin polymer with higher catalytic activity and excellent stereoregularity than the above methods. As a result, by using a solid catalyst obtained by catalytically treating a magnesium halogen compound with a titanium compound of a specific composition, α-olefins such as propylene can be polymerized into extremely highly active and highly stereoregular polymers. They discovered this and arrived at the present invention.

<Means for solving the problems> That is, the present invention provides (A) (a) magnesium dihalide (b) general formula Ti(OC ₆ H ₅ ) _o X _4-o (X represents halogen, n is 0 < n < 1)), and (B) a solid catalyst obtained by contact reaction with a titanium compound represented by the formula RmAlY _3-n (R is a number having 1 to 8 carbon atoms). Alkyl group, Y represents halogen, m is 2≦
m≦3. ) in the presence of a catalyst system consisting of an activator consisting of an organoaluminum compound represented by
- Homopolymerization of olefin or α- having 3 to 8 carbon atoms
Olefin and ethylene or α with 3 to 8 carbon atoms
- A method for producing a highly stereoregular α-olefin polymer characterized by copolymerizing an olefin.

In the present invention, the magnesium halogen compound used in the contact reaction with the titanium compound is magnesium dihalide, and among them, magnesium chloride is preferably used.

The magnesium dihalide is preferably in an active form before or during the contact reaction with the titanium compound. Here, the active form of magnesium dihalide refers to ordinary inactive magnesium dihalide in which the most intense diffraction line in the X-ray powder spectrum has been changed into a halo. It is desirable to use magnesium dihalide in its active form because it allows for a greater amount of the titanium compound to be chemically bonded thereto.

The active form of magnesium dihalide can be obtained in various ways.

One preferred method is to mechanically grind commercially available magnesium dihalide. Grinding is carried out using a ball mill, vibration mill, impact mill, or the like. The grinding time varies depending on the equipment, but is generally from 1 hour to 1000 hours.

The grinding temperature is selected within the range of room temperature to 100°C. Silicone oil or the like may be present in order to facilitate pulverization. Other inert solid fillers may also be present during grinding.

Another preferred method is to dissolve magnesium dihalide in a polar solvent such as alcohol, ether, or amine, and then precipitate a solid. Precipitation can be performed by cooling the solution or evaporating the solvent. The obtained precipitated solid is treated with a halogenating agent such as a silicon halide compound or an aluminum halide compound,
It is desirable to wash with an inert hydrocarbon solvent or the like.

Preferred magnesium halogen compounds include those obtained by decomposing organomagnesium compounds such as alkylmagnesium halides and dialkylmagnesiums with known decomposers such as HCl.

The organomagnesium compound can be used as a solution or suspension in an ether solvent, a hydrocarbon solvent, or a mixed solvent of both.

The magnesium halogen compound is subjected to the next contact reaction step with a titanium compound, but before that, it can be contacted with an electron-donating compound.

Examples of electron-donating compounds include amines, amides,
Examples include ether, ester, ketone, nitrile, phosphine, phosphite, and sulfide compounds, but ester compounds are preferred.

As the ester compound, aliphatic carboxylic acid esters, alicyclic carboxylic acid esters, aromatic carboxylic acid esters, etc. are used, and olefin carboxylic acid esters or aromatic monocarboxylic acid esters are preferred. Especially preferred are esters of aromatic monocarboxylic acids. Specific examples include methyl benzoate, ethyl benzoate, and ethyl p-anisate.

The amount of the electron donating compound used is 10 ^-5 mol to 0.1 mol, preferably 5 x 10 ^-4 mol to 0.02 mol, per gram of the magnesium halide compound.

If it is less than 10 ^-5 mol, there is no effect of improving stereoregularity, and if it is more than 0.1 mol, the polymerization activity is significantly reduced.

The magnesium halogen compound and the electron-donating compound can be brought into contact with each other by any known method capable of bringing the two into contact, such as a slurry method or mechanical pulverization using a ball mill. In particular, a slurry method in which the two are brought into contact in the presence of a diluent is advantageous in terms of particle shape and particle size distribution.

Diluents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, benzene,
Aromatic hydrocarbons such as toluene and xylene, and alicyclic hydrocarbons such as cyclohexane and cyclopentane can be used.

The amount of diluent used is from 0.1 ml per 1 g of solid product.
It is 1000ml. Preferably 1ml to 100ml per 1g
It is. The reaction temperature is -50°C to 150°C, preferably 0°C to 100°C. The reaction time is 10 minutes or more, preferably 30 minutes to 3 hours.

After the contact treatment with the electron donating compound, washing with an inert hydrocarbon solvent or the like may be performed, or the next step of contact reaction with a titanium compound may be carried out without washing.

Such contact treatment with an electron-donating compound somewhat improves the activity and stereospecificity of the resulting solid catalyst, but generally increases the amount of hydrogen used for controlling the molecular weight.

The catalyst of the present invention is characterized in that it exhibits sufficiently high activity and stereospecificity even without the step of contacting with an electron-donating compound as described above.

The titanium compound used in the present invention has the general formula Ti
It is a phenoxytitanium halide compound represented by (OC ₆ H ₅ ) _o X _4-o . That is, Ti _{( OC6H5} ) _X3
and TiX ₄ .

X represents halogen, such as chlorine, bromine, and iodine. Among them, chlorine is preferred.

n is a number expressed as 0<n<1. n=
If it is 0, a satisfactory effect of improving stereoregularity cannot be obtained. Furthermore, if n≧1, a sufficiently high activity cannot be obtained. In particular, n is 0.02.
≦n≦0.8 is preferred. That is, Ti(OC ₆ H ₅ )X ₃ and
The mixing ratio with TiX ₄ is preferably 0.02:0.98 to 0.8:0.2. By using such a specific phenoxytitanium halide compound, it is possible to perform a contact reaction with a corresponding titanium halide, a monophenoxytitanium halide compound, or a support that has been contact-treated with phenol and a halogen. The activity and stereospecificity of the catalyst are dramatically improved compared to when it is brought into contact with titanium chloride.

A titanium compound can be synthesized by a known method.

One method is to synthesize it by a substitution reaction between a halogen-containing titanium compound and phenol.
When the two are mixed, hydrogen halide is generally generated and the reaction proceeds. For use in the present invention, it is necessary that the substitution reaction be substantially complete. Completion of the reaction can be confirmed by the presence or absence of absorption of OH groups in the infrared absorption spectrum of the reactant. For example, 0.1 mole of titanium tetrachloride
When 0.05 mol of phenol is mixed at 120° C., HCl gas is vigorously evolved for about 30 minutes, and a titanium compound of average composition (C ₆ H ₅ O) _0.5 TiCl _3.5 , i.e.
A mixture of (C ₆ H ₅ O)TiCl ₃ and TiCl ₄ in a molar ratio of 1:1 is obtained.

Alternatively, a reaction product resulting from a disproportionation reaction between a phenol orthotitanate ester and a halogen-containing titanium compound can also be used. for example
When 0.39 mol of titanium tetrachloride and 0.01 mol of tetraphenoxy titanium are mixed, the average composition (C ₆ H ₅ O) _{is 0.1}
TiCl _3.9 titanium compounds, viz. ( _{C6H5O ) TiCl3}
A mixture of TiCl 4 and TiCl ₄ in a molar ratio of 1:9 is obtained.

Examples of the halogen-containing titanium compound used in the above synthesis include titanium tetrahalides such as titanium tetrachloride and titanium tetrabromide, and halogenated titanates such as phenoxytitanium trichloride and diphenoxytitanium dichloride. However, titanium tetrahalides, especially titanium tetrachloride, are preferred.

The contact reaction between the magnesium halogen compound (a) and the titanium compound (b), which may or may not have been previously subjected to contact treatment with an electron-donating compound, can be carried out by other known methods such as pulverization using a ball mill, vibration mill, etc. Alternatively, a slurry method in which a magnesium halogen compound is slurried in a titanium compound-containing solution, or an impregnation method in which a magnesium halogen compound is impregnated with a titanium compound-containing solution can also be used.

The titanium compound-containing liquid may be the liquid titanium compound itself, or may be one dissolved in an appropriate solvent.

The amount of the titanium compound-containing liquid used per 1 g of the magnesium halogen compound is 0.1 ml to 100 ml, preferably about 0.5 ml to 50 ml.

This catalytic reaction is preferably carried out at a temperature of 0 to 150°C.

The reaction time is several minutes or more, preferably 30 minutes to 3 hours.

After the contact reaction, it is desirable to wash thoroughly with an inert solvent.

In this way, the solid catalyst of the present invention (A) is obtained.

The activator (B) used in the present invention has the general formula
RmAlY _3-n (R is an alkyl group having 1 to 8 carbon atoms,
Y represents halogen, and m is a number represented by 2≦m≦3. ) is an organoaluminum compound represented by

Specific examples of the organoaluminum compound include trialkylaluminum, a mixture of trialkylaluminium and dialkylaluminum halide, dialkylaluminum halide, etc., and triethylaluminum and a mixture of triethylaluminum and diethylaluminum chloride are particularly preferably used.

The molar ratio of titanium atoms to activator in the solid catalyst used for polymerization of α-olefin is 10:1 to 1:
Although it can be selected from a wide range such as 1000, a range of 2:1 to 1:600 is particularly preferably used.

The method of the present invention involves polymerizing or copolymerizing α-olefin in the presence of the solid catalyst (A) and the activator (B). can be added.

Addition of an electron-donating compound generally improves stereospecificity but decreases activity.

Examples of the electron-donating compound (C) include amines, amides, ethers, ketones, nitriles, phosphine phosphites, sulfide compounds, etc., but ester compounds are preferred. As ester compounds, olefin carboxylic acid esters,
Alternatively, esters of aromatic monocarboxylic acids are preferred. Specific examples include methyl methacrylate, ethyl benzoate, ethyl p-anisate, and methyl p-toluate.

The molar ratio of activator and electron donating compound is 1:
In the range of 0.01 to 1:10, preferably 1:
It ranges from 0.1 to 1:1. The electron-donating compound may be used in advance by mixing it with an activator.
As a combination of an activator and an electron donating compound,
A system of triethylaluminum and ester compounds,
A system of triethylaluminum, diethylaluminum chloride and an ester compound is preferred.

Polymerization can be carried out over a temperature range of -30 to 200°C, but temperatures below 0°C result in a decrease in the polymerization rate, and temperatures above 100°C make it impossible to obtain highly stereoregular polymers. For these reasons, it is usually preferable to carry out the reaction at a temperature in the range of 0 to 100°C. Although there are no particular limitations on the polymerization pressure, a pressure of about 3 to 100 atm is desirable from the viewpoint of industrial and economical considerations.

The polymerization method can be either continuous or batchwise. Further, slurry polymerization using an inert hydrocarbon solvent such as propane, butane, pentane, hexane, heptane, or octane, liquid phase polymerization without a solvent, or gas phase polymerization is also possible.

Next, α-olefins that can be applied to the present invention have 3 to 8 carbon atoms, and specific examples include propylene, butene-1, pentene-1, hexene-1, 3-methyl-pentene-1, 4-methyl-
Examples include pentene-1, but the present invention is not limited to the above compounds. The polymerization according to the present invention can be either homopolymerization or copolymerization (including copolymerization with ethylene).
During copolymerization, a copolymer can be obtained by contacting two or more types of α-olefins in a mixed state.

Heteroblock copolymerization in which polymerization is carried out in two or more stages can also be easily carried out.

The method of the present invention will be explained below using Examples, but the present invention is not limited to these Examples in any way.

<Example> Example 1 (A) Grinding treatment of anhydrous magnesium chloride After replacing the pot of a vibrating mill with argon, the pot was equipped with a grinding pot with an internal volume of 500 ml and containing 60 stainless steel (SUS32) balls with a diameter of 12 mm. Commercially available anhydrous magnesium chloride (6 at 400℃ under reduced pressure)
Time firing) 20g was charged and pulverized for 100 hours.

(B) Synthesis of titanium compound After purging a 200ml flask equipped with a stirrer and thermometer with argon, titanium tetrachloride was added.
35.7 ml and 15.3 g of phenol were charged, and the temperature was raised to 120°C.

The reaction proceeded with the generation of hydrogen chloride gas.

After maintaining this temperature for 1 hour, 1 ml of the dark red reaction solution was collected and the infrared absorption spectrum was measured. No absorption based on stretching vibration of the OH group of phenol was observed, and the average composition of Ti
(OC ₆ H ₅ ) _0.5 Cl _3.5 , the liquid titanium compound shown was obtained.

(C) Synthesis of solid catalyst Add 5 g of anhydrous magnesium chloride obtained in (A) above to the liquid containing the titanium compound synthesized in (B) above.
After charging, a contact reaction was carried out at 120° C. for 1 hour while stirring.

After the reaction was completed, the mixture was allowed to stand still and the supernatant liquid was extracted at 120°C.

Next, 50 ml of n-heptane was added, and after stirring at 90°C for 5 minutes, the mixture was allowed to stand and the supernatant liquid was extracted.
This operation was repeated 5 times for washing. After drying under reduced pressure, 4.5 g of solid catalyst was obtained.

This solid catalyst contained 1.6% by weight of titanium atoms.

(D) Polymerization of propylene () A stirred stainless steel autoclave with an internal volume of 5 was replaced with argon and dried heptane 1.5
, 0.75 g of triethylaluminum, 0.217 g of methyl toluate, and 62 mg of the solid catalyst synthesized in (C) above were charged, and hydrogen corresponding to a partial pressure of 0.14 Kg/cm ² was added.

Next, the temperature of the autoclave was raised to 70°C, and then propylene was pressurized to 6 kg/cm ² G to start polymerization, and the polymerization was continued for 90 minutes while replenishing propylene to maintain this pressure.

After the polymerization was completed, the introduction of monomers was stopped, unreacted monomers were purged, and 100 ml of butanol was added to decompose the catalyst.

The produced polymer was filtered through a Buchner filter, washed three times with 500 ml of heptane, and dried at 60°C, yielding 110 g of polypropylene.

Heptane was removed from the liquid by steam distillation, yielding 9.7 g of an amorphous polymer.

The proportion of heptane-insoluble parts (hereinafter abbreviated as HIP) in the total polymer yield was 91.9% by weight.
Further, the yield (g) of polypropylene per 1 g of solid catalyst (hereinafter abbreviated as PP/Cat) was 1930.

(E) Polymerization of propylene () In (D) polymerization of propylene (), 76 mg of the solid catalyst synthesized in (C) was used and 0.375 g of triethyl aluminum was used instead of 0.75 g of triethyl aluminum as an organoaluminum compound.
Polymerization of propylene was carried out in the same manner except that 0.397 g of a mixed organoaluminium compound of diethylaluminium chloride was used and 0.3 g of ethyl p-anisate was used instead of methyl toluate.

113 g of polypropylene powder was obtained. Also,
9.0 g of amorphous polymer was obtained.

Therefore, PP/Cat=1610 and HIP=92.6
It was in weight%.

(F) Polymerization of propylene () After purging a stirring stainless steel autoclave with an internal volume of 5 with argon, 0.65 g of triethylaluminum, 0.257 g of methyl toluate
g and 50 mg of the solid catalyst synthesized in (C) above were charged, and hydrogen corresponding to a partial pressure of 0.40 Kg/cm ² was added.

Then, 1.3 kg of liquid propylene was pressurized into the autoclave, and the autoclave was kept at 65°C to continue polymerization for 2 hours.

After the polymerization was completed, unreacted monomers were purged, and 100 ml of methanol was added to decompose the catalyst.

The produced polypropylene was filtered through a Buchner filter and dried under reduced pressure at 60°C, yielding 180 g of polypropylene.

PP/Cat=3600. Further, when Soxhlet extraction with boiling heptane was performed for 6 hours, the proportion of insoluble portion was 91.3% by weight.

Example 2 Liquid titanium having an average composition of Ti(OC ₆ H ₅ ) _0.1 Cl _3.9 was prepared in the same manner as in Example 1 (B) except that the amount of phenol used was changed to 3.06 g. The compound was synthesized.

Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 instead of Ti(OC ₆ H ₅ ) _0.
A solid catalyst was synthesized in the same manner as in Example 1 except that _3.9 Cl ₁ was used.

Using 56 mg of the above solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D).

PP/Cat=2020, HIP=92.1% by weight.

Example 3 Liquid titanium having an average composition of Ti(OC ₆ H ₅ ) _0.7 Cl _3.3 was prepared in the same manner as in Example 1 (B) except that the amount of phenol used was changed to 21.4 g. The compound was synthesized.

Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 instead of Ti(OC ₆ H ₅ ) _0.
A solid catalyst was synthesized in the same manner as in Example 1 except that ₇ Cl _3.3 was used.

Using 74 mg of the above solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D). PP/Cat
= 1750, HIP = 91.6% by weight.

Example 4 (A) Synthesis of ethyl benzoate-treated solid A 100 ml flask equipped with a stirrer and a dropping funnel was purged with argon, and then 7.5 g of anhydrous magnesium chloride prepared in (A) of Example 1 was charged.
75 mg of n-heptane was added to form a slurry.

Subsequently, 2.25 ml of ethyl benzoate was charged with stirring, and the reaction was carried out at 30°C for 1 hour.

After the reaction, the reaction mixture was allowed to stand, and the supernatant was separated, washed three times with 50 ml of n-heptane, and dried under reduced pressure to obtain 7.0 g of ethyl benzoate-treated solid.

(B) Synthesis of solid catalyst Ethyl benzoate treated solid 5 synthesized in (A) above
A solid catalyst was synthesized under the same conditions as in Example 1 (B) and (C) except that g was used.

(C) Polymerization of propylene In the polymerization of propylene in (D) of Example 1 using 32 mg of the solid catalyst synthesized in (B) above, the amount of triethylaluminum used was 0.15 g, except that methyl toluate was not used. carried out the polymerization of propylene in a similar manner.

157 g of polypropylene powder was obtained. Also,
18.7 g of amorphous polymer was obtained.

Therefore, PP/Cat=5490 and HIP=89.4
It was in weight%.

Example 5 Using 65 mg of the solid catalyst synthesized in Example 4, propylene was polymerized under the same conditions as in Example 1 (D).

PP/Cat=2100, HIP=92.8% by weight.

Example 6 (A) Synthesis of magnesium compound A 200 ml flask equipped with a stirrer, a dropping funnel, and a reflux condenser was purged with argon, and then 10 g of commercially available anhydrous magnesium chloride (calcined under reduced pressure at 400°C for 6 hours) was charged. is. 170℃ under stirring
Then, 36.4 ml of ethanol was added dropwise from the dropping funnel.

After completely dissolving the magnesium chloride,
MgCl ₂ 6C ₂ H ₅ OH by cooling to 20℃
was prepared.

Next, after adding 300ml of silicon tetrachloride,
The reaction was carried out under reflux for 12 hours.

After the reaction, let it stand and remove the supernatant,
Washing 5 times with 50 ml of n-heptane and drying under reduced pressure gave a white solid product.

(B) Synthesis of titanium compounds 0.041 mol Ti(OC ₆ H ₅ ) ₄ and 0.284 mol TiCl ₄
A liquid titanium compound having an average composition of Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 was synthesized by mixing.

(C) Synthesis of solid catalyst Example 1 except that the solid product synthesized in (A) and the liquid titanium compound synthesized in (B) with an average composition of Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 were used. A solid catalyst was synthesized in a similar manner.

(D) Polymerization of propylene Using 65 mg of the solid catalyst obtained in (C) above, Example 1
Polymerization of propylene was carried out under the same conditions as in (D).

PP/Cat=2320, HIP=92.3% by weight.

Comparative Example 1 Same as Example 1 except that magnesium chloride prepared in (A) of Example 1 was used and titanium tetrachloride was used instead of the titanium compound having an average composition of Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 . A solid catalyst was synthesized in a similar manner.

Using 120 mg of this solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D).

PP/Cat=820, HIP=89.0% by weight.

Comparative Example 2 An ethyl benzoate-treated solid was synthesized under the same conditions as in Example 4 (A), and in the synthesis of the solid catalyst in Example 4 (B), the average composition was Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 A solid catalyst was synthesized in the same manner as in Example 4 (B), except that titanium tetrachloride was used instead of the titanium compound represented by.

Using 45 mg of this solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D).

PP/Cat=795, HIP=90.4% by weight.

Comparative Example 3 Using 45 mg of the solid catalyst synthesized in Comparative Example 2, propylene polymerization was carried out under the same conditions as in Example 4 (C).

PP/Cat=2060, HIP=86.8% by weight.

Comparative Example 4 A liquid titanium compound having an average composition of Ti(OC ₆ H ₅ ) Cl ₃ was prepared in the same manner as in Example 1 (B) except that the amount of phenol used was changed to 30.6 g. was synthesized.

Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 instead of the above Ti(OC ₆ H ₅ )
A solid catalyst was synthesized in the same manner as in Example 1 except that Cl ₃ was used.

Using 74 mg of the above solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D).

PP/Cat=1270, HIP=90.4% by weight.

Comparative Example 5 An ethyl benzoate-treated solid was synthesized under the same conditions as in Example 4 (A), and Ti(OC ₆ H ₅ ) _0.5 was replaced with Cl _3.5 in the synthesis of the solid catalyst in Example 4 (B). average composition to
A solid catalyst was synthesized in the same manner as in Example 4 (B) except that a titanium compound represented by Ti(OC ₆ H ₅ )Cl ₃ was used.

Using 36 mg of this solid catalyst, propylene polymerization was carried out under the same conditions as in Example 4 (C).

PP/Cat=3560, HIP=88.2% by weight.

Example 7 After purging the pot of a vibrating mill equipped with a 500 ml grinding pot containing 60 stainless steel (SUS32) balls with a diameter of 12 mm with argon, commercially available anhydrous magnesium chloride (commercially available anhydrous magnesium chloride (at 400°C under reduced pressure for 6 hours) was used. firing)
20g was charged and ground for 100 hours.

Next, 2 g of a titanium compound synthesized under the same conditions as in Example 1 (B) and having an average composition of Ti(OC ₆ H ₅ ) _0.5 Cl _3.5 was added, and the solid catalyst was further pulverized for 24 hours. Prepared.

Using 74 mg of the above solid catalyst, propylene polymerization was carried out under the same conditions as in Example 1 (D).

PP/Cat=1510, HIP=91.3% by weight.

<Effects of the invention> (1) Catalytic efficiency per solid catalyst and per titanium atom is extremely high. As a result, there are extremely few transition metal (titanium) residues or halogen residues that remain in the produced polymer and deteriorate the physical properties of the product polymer, such as hue, thermal stability, corrosion resistance, and foamability.
No catalyst residue removal step is required.

(2) In addition to being highly active as described above, sufficiently high stereoregularity can be obtained. That is, since the amount of amorphous polymer that is industrially of low value and remains in the produced polymer and deteriorates the mechanical properties and blocking properties of the film is small, there is no need for a step for removing it.

(3) The manufacturing process of the solid catalyst is extremely simple, and a solid catalyst with high activity and high stereospecificity can be obtained at low cost.

(4) The amount of hydrogen used for controlling the molecular weight during polymer production can be reduced, making it easy to control the molecular weight.

[Brief explanation of drawings]

FIG. 1 is a flowchart to aid in understanding the present invention. This flowchart is a representative example of the embodiment of the present invention, and the present invention is not limited thereto.

Claims (1)

[Claims] 1 (A) (a) Magnesium dihalide, (b) General formula Ti(OC ₆ H ₅ ) _o X _4-o (X represents halogen, n is 0<n<1) _A solid catalyst obtained by contact reaction with a titanium compound represented by and m is 2≦
m≦3. ) in the presence of a catalyst system consisting of an activator consisting of an organoaluminum compound represented by
- Homopolymerization of olefin or α- having 3 to 8 carbon atoms
A method for producing a highly stereoregular α-olefin polymer, which comprises copolymerizing olefin with ethylene or another α-olefin having 3 to 8 carbon atoms.