JPS581121B2 - Method for producing α-olefin polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing α-olefins, particularly polymers of α-olefins such as ethylene, propylene, butene, and the like.

Conventionally, various solid titanium trichloride and solid titanium trichloride/aluminum trichloride eutectic and the like have been known as polymerization catalysts for producing α-olefin polymers.

For example, there is solid α-type titanium trichloride obtained by reducing titanium tetrachloride with hydrogen gas at high temperatures.
Type titanium trichloride has low polymerization activity as a catalyst for α-olefin polymerization, produces a polymer containing a large amount of amorphous polymer, and is insufficient in terms of stereoregular polymerization.

In addition, a solid eutectic of titanium trichloride and aluminum chloride obtained by reducing titanium tetrachloride with metallic aluminum at high temperature is known, and in this case titanium trichloride is known as γ-type or α-type titanium trichloride. As is known, this solid eutectic has low polymerization activity and is insufficient in terms of stereoregular polymerization as a catalyst for α-olefin polymerization, and produces a polymer containing a large amount of amorphous polymer.

Further, titanium trichloride obtained by reducing titanium tetrachloride with an organometallic compound of aluminum is generally a brown solid titanium trichloride and is known as the β type.

In order to use titanium trichloride in this case as a catalyst for the polymerization of α-olefin and to improve the stereoregularity of the polymer, it is heat-treated at 150°C or higher using a generally known method. It is necessary to convert it into purple titanium trichloride, but this purple solid titanium trichloride also has low polymerization activity as a catalyst for α-olefin polymerization, is insufficient in terms of stereoregular polymerization, and is a large amount of amorphous polymer. to produce a polymer containing.

Furthermore, a method of converting solid β-type titanium trichloride to purple titanium trichloride by treating it with a complexing agent and heat-treating it in titanium tetrachloride is also proposed by Solvay and is publicly known.

In addition, there are also known methods in which various titanium trichlorides obtained by the above-mentioned known methods are further treated with various complexing agents, methods in which they are ground in a ball mill in the presence or absence of various complexing agents, etc. It is also known to obtain solid titanium trichloride by reducing titanium tetrachloride with an organometallic compound of aluminum in the presence of an electron-donating compound such as an ether; No excellent titanium trichloride catalysts capable of producing polymers with high polymerization activity and high stereoregularity have been produced.

As a result of research to improve the above-mentioned drawbacks, the present inventors discovered a method for precipitating solid titanium trichloride from solubilized titanium trichloride, which was filed in Japanese Patent Application No. 49-8847.
As shown in No. 7 and the like, it was possible to obtain an α-olefin polymerization catalyst which was excellent in terms of the stereoregularity of the produced polymer and the polymerization activity.

However, for the industrial production of α-olefin polymers, the bulk density and particle size distribution of the polymer are well known to be important in addition to the above-mentioned polymerization activity and stereoregularity.

That is, polymers with higher bulk density and more uniform particle size distribution have better flowability and are easier to operate;
Furthermore, higher industrial productivity can be obtained.

The present inventors aimed to further improve the aforementioned improved solid titanium trichloride catalyst, that is, the titanium trichloride catalyst precipitated from solubilized titanium trichloride, in terms of the bulk density and particle size distribution of the resulting polymer. As a result of repeated studies, the inventors learned that the conditions for precipitating titanium trichloride described above are important, and the present invention was achieved.

The gist of the paper is to conduct the polymerization of α-olefin with solid titanium trichloride and the general formula AlR'nX3-n (where R
' is an alkyl group having 1 to 8 carbon atoms, n is a number of 1 to 3,
In the method carried out in the presence of a catalyst system consisting of an organoaluminum compound represented by (X represents a halogen atom), the solid titanium trichloride is prepared by using titanium tetrachloride in the presence of ether with the general formula (1) AlRnX3- n...
・・・・・・・・・(1) (In the formula, R has 1 to 20 carbon atoms
A liquid obtained by treating with an organoaluminum compound represented by a hydrocarbon group, n is a number from 1 to 3, and , a method for producing an α-olefin polymer, characterized in that it uses fine-grained purple solid titanium trichloride precipitated by contact with a liberating agent.

To more specifically summarize and explain the features of the method for producing solid titanium trichloride used in the method of the present invention, the first feature is that a certain ether compound and, if necessary, a certain hydrocarbon solvent are used. The second feature lies in the method of obtaining a homogeneous liquid material of titanium trichloride soluble in a hydrocarbon solvent by reducing titanium tetrachloride with an organoaluminum compound in the presence of a hydrocarbon solvent. The method involves precipitating a purple solid titanium trichloride with excellent olefin polymerization activity from a homogeneous liquid titanium trichloride.The third feature is that the above precipitation is performed in multiple stages at different temperatures. Preferably, a small portion is precipitated at a relatively low temperature, and then the majority is precipitated at an elevated temperature.

The ether compound used in the method of the present invention may be any compound as long as it satisfies the first feature of the method of the present invention described above, and preferably, an ether compound that is soluble in a hydrocarbon solvent is selected. The following general formula (2
) R1OR2 ・・・・・・・・・・・・・・・(2)(
In the formula, R1 and R2 are the same or different alkyl groups, aralkyl groups, alkenyl groups, aryl groups, and alkaryl groups.

Specific examples of these ethers include di-n-amyl ether, di-n-butyl ether, di-n-propyl ether, di-n-hexyl ether, di-n-heptyl ether, and di-n-octyl ether. Ether, di-n-decyl ether, di-n-dodecyl ether, di-n-tridecyl ether, n-amyl-n-butyl ether,
n-amyl isobutyl ether, n-amyl ethyl ether, n-butyl-n-propyl ether, n-butyl isoamyl ether, n-ethyl-n-hexyl ether, n-propyl-n-hexyl ether, n-butyl-n -Dialkyl ethers such as octyl ether, n-hexyl-n-octyl ether; bis(1-butenyl) ether, bis(1-octenyl) ether, bis(
Dialkenyl ethers such as 1-decynyl) ether and 1-octenyl-9-decynyl ether; dialkyl ethers such as bis(benzyl) ether; bis(tolyl)
Dialkaryl ethers such as ether, bis(xylyl) ether, bis(ethylphenyl) ether, tolyl xylyl ether; propyl-1-butenyl ether;
n-octyl-1-decynyl ether, n-decyl-1
- alkyl alkenyl ether such as decynyl ether;
Alkyl aralkyl ethers such as n-octyl-benzyl ether and n-decyl-benzyl ether; alkylaryl ethers or alkyl alkaryl ethers such as n-octyl phenyl ether, n-octyl-tolyl ether, and n-decyl-tolyl ether; Aralkylalkynyl ethers such as 1-octenyl-benzyl ether; 1-octenyl-phenyl ether, 1-
Examples include aryl alkenyl ethers or alkaryl alkenyl ethers such as octenyl tolyl ether; aralkyl aryl ethers or aralkyl alkaryl ethers such as benzyl phenyl ether and penzyl tolyl ether, and preferably those in formula (2) above. Ethers in which R1 and R2 are linear hydrocarbon residues such as alkyl groups or alkenyl groups are used.

The organoaluminum compound used as a reducing agent in the method of the present invention is a compound represented by the above general formula (1), and a compound in which R in the formula is an alkyl group having 1 to 10 carbon atoms is particularly desirable.

First, the reduction treatment of titanium tetrachloride with an organoaluminum compound, which is the first feature of the method for producing solid titanium trichloride used in the method of the present invention, is performed using the above-mentioned ether compound (hereinafter abbreviated as ether) and This can be carried out by any method as long as a suitable hydrocarbon solvent is present as necessary, and examples of such methods include the following methods.

(a) A method in which an organoaluminum compound is added to a homogeneous liquid material consisting of titanium tetrachloride and ether, or the order of addition is reversed.

(b) A method in which a homogeneous liquid material consisting of an organoaluminum compound and ether is added to titanium tetrachloride, or the order of addition is reversed.

(c) A method in which a homogeneous liquid substance consisting of an organoaluminum compound and ether is added to a homogeneous liquid substance consisting of titanium tetrachloride and ether, or the order of addition is reversed.

(d) A method in which titanium tetrachloride, ether, and organic aluminum are mixed in any order at a temperature below the reduction temperature, for example, below -30°C, and then the temperature is raised to a predetermined reduction temperature.

In these methods, titanium tetrachloride, ether, and organoaluminum compound may be used in pure form, or may be diluted with a hydrocarbon solvent as appropriate.

However, it is preferable to use the organoaluminum compound diluted with a hydrocarbon solvent.

Also, depending on the type of ether, during the above reduction process,
Only in the presence of a suitable hydrocarbon solvent can the first method of the present invention be achieved.
Some achieve the characteristics of

As such an ether, for example, in the above formula (2), at least one of R1 and R2 is a hydrocarbon group having 5 or less carbon atoms.

The hydrocarbon solvent used in the above may be any solvent as long as it is suitable for the present invention, and is appropriately selected mainly depending on the type of ether.

Specifically, saturated aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-dodecane, and liquid paraffin; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; benzene, It is appropriately selected from aromatic hydrocarbons such as triene, xylene, 1,2,4-trimethylbenzene, and ethylbenzene.

For example, when the hydrocarbon solvent is an ether in which at least one of R1 and R2 in formula (2) is a hydrocarbon group having 5 or less carbon atoms, it is preferable that an aromatic hydrocarbon is used, followed by an alicyclic group. When R1 and R2 are hydrocarbons having 6 or more carbon atoms, saturated aliphatic hydrocarbons are preferably selected.

Furthermore, the molar ratio of ether to titanium tetrachloride used in these methods is preferably in the range of 1:0.05 to 1:5, particularly preferably in the range of 1:0.25 to 1:2.5. .

However, when the amount of titanium tetrachloride used relative to the ether increases, the polymerization activity of the resulting catalyst tends to decrease, and the yield of the catalyst produced per titanium tetrachloride becomes poor.

On the other hand, when the amount of ether used relative to titanium tetrachloride becomes large, a large amount of liberating agent and/or organoaluminum compound is required, and therefore, the yield of the produced catalyst relative to the liberating agent and/or organoaluminum compound becomes poor.

Furthermore, the molar ratio of titanium tetrachloride to the organoaluminum compound of the above-mentioned reducing agent is determined by the molar ratio between titanium and R (hydrocarbon group, preferably alkyl group) in the organoaluminum compound represented by the general formula (1). Shown in molar ratio, 1:0.1
- 1:50, preferably 1:0.3 - 1:10, and can be arbitrarily selected.

As described above, the liquid obtained by reducing titanium tetrachloride with the organic aluminum represented by the general formula (1) in the presence of the ether is a hydrocarbon-soluble product of titanium trichloride ether. It is a homogeneous solution or mixture that is brown or brownish with a greenish tinge depending on the conditions.

Note that the liquid material made of titanium tetrachloride and ether is a homogeneous solution or mixture with a strong yellowish orange color, and the liquid material made of the organoaluminum compound represented by the general formula (1) and ether is a homogeneous solution or mixture. The mixture is almost colorless.

The second feature of the method for producing solid titanium trichloride used in the present invention is the method of precipitating purple solid titanium trichloride from a liquid material. This is carried out by contacting the diluted solution, optionally with the hydrocarbon diluent mentioned above, with a liberating agent at a temperature below 150°C.

At this time, in order to advantageously form a precipitate, it is preferable that the above-mentioned hydrocarbon solvent be present in an amount of at least 2 times the weight of the ether.

Examples of liberating agents used in the method of the present invention include Lewis acids that are more acidic than titanium trichloride, such as titanium tetrachloride, boron trifluoride, boron trichloride, antimony pentachloride, gallium trichloride, iron chloride, tellurium dichloride,
Examples include tin tetrachloride, vanadium tetrachloride, thallium pentachloride, zirconium tetrachloride, beryllium dichloride, bromides corresponding to these, oxyhalide compounds, etc., and further, general formula (3) AlR'rnX3-rn...・・・・・・
・(3) (wherein, R' is an alkyl group having 1 to 8 carbon atoms,
is a halogen atom, m is a number of 0, 1, 1.5 or 2), etc.
Among them, titanium tetrachloride is preferred.

When the above-mentioned liquid is brought into contact with this liberating agent to react effectively, if the total number of moles of titanium and aluminum in the liquid is less than the number of moles of ether, it is necessary to use the liberating agent. For example, a Lewis acid that is more acidic than the titanium trichloride mentioned above is added so that the total number of moles of titanium (titanium trichloride), aluminum (organometallic compound), and Lewis acid is small (at least the number of moles of ether). However, it is desirable that the amount of the Lewis acid added is not more than 5 times the molar amount of titanium.

On the other hand, if the total number of moles of titanium and aluminum in the above-mentioned liquid is greater than the number of moles of ether (however, titanium is particularly preferably 2.5 times the mole of ether or less), the above-mentioned liberating agent may be used. There is no need to add such a Lewis acid, and it is sufficient to proceed directly to the next step of precipitating fine-grained solid titanium trichloride by raising the temperature to 150° C. or lower.

That is, the second feature of the method for producing solid titanium trichloride used in the method of the present invention, which is the method of bringing a liquid substance into contact with a liberating agent at 150° C. or lower to precipitate fine solid titanium trichloride, is the same as described above. Bringing the liberating agent added to the liquid material or the liberating agent already present in the liquid material (e.g., excess titanium tetrachloride) and the titanium trichloride liquid material in the liquid material into a contact reaction by raising the temperature. This method generates and precipitates purple fine granular solid titanium trichloride.

Next, the third feature, a method of causing the above-mentioned precipitation in multiple stages at different temperatures, will be explained.

In this multi-stage precipitation method, it is preferable to precipitate a small portion at a relatively low temperature, and then to precipitate the majority by raising the temperature in the presence of a small amount of precipitated fine particulate solid titanium trichloride.

The precipitation conditions differ somewhat depending on the above-mentioned titanium tetrachloride, ether, organoaluminum compound, liberating agent mutual molar ratio, and hydrocarbon solvent used.
1 to 50% by weight, preferably 2 to 25% by weight, particularly preferably 3 to 20% by weight of the total theoretical precipitation amount in a relatively low temperature range of 0 to 70°C, preferably 35 to 55°C. A quantity of a very finely divided purple solid titanium trichloride is precipitated at a temperature below 150°C, for example from 60 to 150°C, preferably from 70 to 120°C, particularly preferably from 85 to 100°C.
The remaining purple fine-grained solid titanium trichloride is precipitated by increasing the temperature within the temperature range of .

Although the precipitation time varies depending on other precipitation conditions, the precipitation stage at a relatively low temperature usually takes 5 minutes to 120 minutes, preferably 10 minutes to 60 minutes, and the next precipitation stage at a relatively high temperature usually takes 2 minutes. The time is from 10 minutes to 120 minutes, preferably from 10 minutes to 60 minutes.

Furthermore, multi-steps at different temperatures may be any method as long as the above-mentioned precipitation conditions are met; for example, precipitation may be performed by changing the temperature in two or more steps. In some cases, the precipitation may be performed while continuously changing the precipitation temperature.

In short, in the present invention, as described above, it is essentially important that the solid titanium trichloride precipitated in a relatively low temperature region accounts for a specific amount of the total titanium trichloride to be precipitated.

This titanium trichloride precipitate is separated and washed to obtain a new purple titanium trichloride catalyst.

The titanium trichloride obtained by performing such a specific precipitation method has a suitable particle size, for example, about 30 to 55μ, as a catalyst, and its shape is surprisingly almost perfect sphere. shows the spherical shape of

When the purple solid titanium trichloride catalyst produced by the method described above is subjected to an α-olefin polymerization system together with a cocatalyst according to the method of the present invention, the bulk density of the resulting polymer is greatly improved; Its major feature is that the particle size distribution can be made more uniform, resulting in good fluidity and high industrial productivity.

In addition, as mentioned earlier, the fact that the shape is almost a perfect sphere causes the shape of the produced polymer to also be close to a perfect sphere, and this, together with the catalyst itself, causes the produced polymer to have a nearly perfect spherical shape. Improves particle fluidity extremely well.

However, it is a well-known fact that the shape of the polymer obtained by using, for example, a titanium trichloride catalyst pulverized with a commercially available ball mill etc., is in the form of a flat plate, and the fluidity of these particles is Considering that this cannot necessarily be said to be satisfactory, the present invention has great industrial value in this respect as well.

Further, almost no aluminum compound component is detected in the purple titanium trichloride used in the present invention, and even if there is a large amount, the weight ratio of aluminum to titanium does not exceed 5%.

This is also a feature of the catalyst of the present invention, and it is thought that the small content of the aluminum compound improves the stereoregularity of the produced polymer.

According to the method for producing a solid titanium trichloride catalyst as described in detail above, during the polymerization of α-olefin, the polymerization activity and the stereoregularity of the produced polymer are improved unprecedentedly, and the bulk of the produced polymer is improved. A novel purple solid titanium trichloride, which can be greatly improved in terms of density, particle size distribution, and shape, can be easily and industrially advantageously produced.

In the present invention, the solid titanium trichloride produced in this way is produced by the general formula AIR'n In this method, α-olefin is polymerized in the presence of a catalyst system combined with an organoaluminum compound represented by (X represents a halogen atom).

In the present invention, the organoaluminum compound may be any compound represented by the above general formula, such as diethylaluminum monochloride.

Various known polymerization methods such as solution polymerization, gas phase polymerization, and slurry polymerization can be applied to the α-olefin polymerization method, and various known third components may be added thereto.

Next, the present invention will be explained in more detail using reference examples, working examples, and comparative examples.

In addition, in the Examples and Comparative Examples, the polymerization activity K is 1 g of titanium trichloride per 1 kg/cm2 of propylene pressure per hour.
The amount of polypropylene produced per unit is g.

Catalyst efficiency CE is the amount of polypropylene produced per g of catalyst unit.

Isotactic index I. I. is the residual amount (% by weight) after extraction with boiling n-heptane for 6 hours using an improved Soxhlet extractor.

Since the amorphous polymer is soluble in boiling n-heptane,
I. I. indicates the yield of crystalline polymer.

Intrinsic viscosity [η] is a value measured in tetralin at 135° C. at a concentration of 0.1 g/100 ml.

The bulk density ρB is a value calculated by collecting 20 cc of polymer powder by gravity into a 50 cc measuring cylinder and measuring its weight.

Moreover, the particle size was measured by a sieve fractionation method.

The attached drawings are in Rosin-Rammler paper (for details, see pages 361-362 of the Chemical Engineering Handbook, published by Maruzen Co., Ltd. on May 10, 1961), showing the process (B) of Example 1 and the (B) of Comparative Example 1. B) The particle size distribution of the polypropylene obtained in the process and Comparative Example 3 is shown.

The horizontal axis shows the particle size (μ), and the vertical axis shows the cumulative weight percentage of the specified particle size or more (
R%).

Reference Example 1 (A) Production of homogeneous titanium trichloride solution 150 ml of n-heptane and 90 ml of titanium tetrachloride were placed in a 500 ml four-necked flask that had been thoroughly dried and replaced with argon.
mol and further add 90 m of di-n-octyl ether.
mol was added.

Titanium tetrachloride and di-n-octyl ether reacted with some heat generation to form a transparent orange homogeneous solution uniformly dissolved in n-heptane.

The solution was then stirred and maintained at 25°C for 30 minutes.
15 mmol of diethylaluminum monochloride
ml of n-heptane was slowly added.

Titanium trichloride has a reddish brown color with some heat generation.
- A homogeneous heptane solution was obtained.

In addition, when producing this homogeneous solution, the total molar amount of titanium tetrachloride and diethylaluminum monochloride is 1
20 mmol, while di-n-octyl ether is 90 mmol.

Therefore, the resulting homogeneous solution contains the liberating agent without adding an additional amount of the liberating agent.

(B) Precipitation formation of titanium trichloride and production of catalyst (
The homogeneous solution of titanium trichloride obtained in step A) was stirred for 5 minutes.
When the temperature was raised to 0°C, a very small amount of purple, extremely finely granular titanium trichloride was observed to have precipitated.

Although the mixture was kept at 50° C. for 30 minutes with stirring, the amount of purple titanium trichloride precipitated was about 15% of the theoretical amount.

Next, the temperature was raised to 93°C, and after holding at that temperature for 30 minutes with stirring, the precipitate was separated and washed five times with 100 ml of n-heptane. 8g was obtained.

Example 1 (A) Polymerization of propylene using a flask (B
Propylene polymerization was carried out in a flask using the granular purple titanium trichloride obtained in step ).

That is, 500 ml of n-heptane, 1.6 mmol of diethylaluminum monochloride, and 40.8 mg of the purple titanium trichloride catalyst obtained in the above step (B) were charged into a 1 liter four-necked flask that had been thoroughly purged with dry argon.

Then, the temperature was raised to 70° C. with stirring, propylene gas was introduced at normal pressure, polymerization was carried out for 2 hours, and then a small amount of isopropanol was added to stop the polymerization.

The contents were added to a large amount of methanol, and after drying, 7.6 gr of white powdery polypropylene was obtained.

The CE is 186, the K is 155, and the I. I.
is 94.3%, [η] is 2.72, ρB is 0.273g
/cc.

Furthermore, the particle shape of the polymer was close to a true sphere, and the particle size distribution was also within an extremely narrow range.

(B) Polymerization of propylene using an autoclave Polymerization with high catalytic efficiency was carried out using an induction stirring autoclave with a capacity of 2 liters.

That is, the purple titanium trichloride catalyst 38. obtained in the above step (B) was placed in a sufficiently dried autoclave purged with argon.
Then, under an argon seal, 1.2 mmol of diethylaluminum monochloride was charged, hydrogen gas was sealed at a gauge pressure of 0.85 kg/cm2, and then 500 g of liquid propylene was charged and polymerization was carried out at 70°C. After 1 hour, excess propylene was immediately purged and after cooling, 175 g of white powder polypropylene was obtained.

In this case, CE is 4580, K is 153, [η] of the polymer is 1.63, I. I. is 92.7%, ρB is 0
．． It was 376g/cc.

The shape of the polymer was almost perfectly spherical, and as shown in the accompanying drawings, it had a very narrow particle size distribution, and its particle flowability was good.

Comparative Example 1 A homogeneous solution obtained in the same manner as in Step (A) of Reference Example 1 was immediately heated to 93°C and maintained for 1 hour. Polymerization of propylene was carried out using the granular purple titanium trichloride according to steps (A) and (B) of Example 1, and the following results were obtained.

(A) Results of process (flask polymerization) The yield of white powdery polypropylene was 7. 8g, CE is 191, K is 159, and the I. is 93.7
%, [η] was 2.65.

Further, the ρB of the polymer is 0.197 g/cc, which is a considerably smaller value than the result of step (A) of Example 1.

(B) Process result (autoclape polymerization) The yield of white powdered polypropylene was 185 g, and the CE was 4840.
K of the polymer was 161, [η] was 1.73, I.
I. was 91.9%.

Moreover, ρB is 0.319 g/cc, and (B
) It can be seen that the value is considerably smaller than the result of the process.

Furthermore, the particle size distribution is also as shown in the drawing, B of Example (1).
This shows a wider range than in the case of processes.

Furthermore, the fluidity of the particles was not good. Comparative Example 2 In step (A) of Example 1, 203.6 mg of commercially available titanium trichloride (Toho Titanium Co., Ltd. TAC141) was charged into a flask so that the molar ratio of diethylaluminum monochloride to titanium trichloride was 5.5. Propylene was polymerized in the same manner as in step (A) of Example 1 except for this, and 8.0 g of white powdery polypropylene was obtained.

CE is 39, K is 32.7, and I. I. is 89.7% [η] is 2.76, ρB is 0.260g/c
It was c.

The shape of the polymer was flat, and its particle fluidity was also poor.

Comparative Example 3 Step (B) of Example 1 except that 114.5 mg of commercially available titanium trichloride (Toho Titanium Co., Ltd., TAC-141) and 2.9 mmol of diethylaluminium monochloride were used in Step (B) of Example 1. When propylene was polymerized in the same manner, 118 g of white powdery polypropylene was obtained.

CE is 1,030, K is 34, [η] of the lipolymer is 1.65, I. I. is 86.8%, ρB is 0.277g
/cc.

The shape of the polymer was flat, and as shown in the drawing, the particle size distribution showed a significantly wider range than in the method of the present invention (Step B of Example 1), and the particle fluidity was also extremely poor. .

Example 2 A homogeneous solution obtained in the same manner as in step (A) of Reference Example 1 was heated to 45°C under stirring and held at this temperature for 15 minutes to form extremely fine particles corresponding to about 7% of the final precipitation amount. Purple titanium trichloride was precipitated.

The contents were then heated to 90° C. and 9.4 gg of purple granular titanium trichloride was obtained in the same manner as in step (B) of Reference Example 1, except that the temperature was raised to 90° C. and maintained for one hour while stirring.

Next, using this, propylene was polymerized in the same manner as in steps (5) and (B) of Example 1, and the following results were obtained.

(A) Process result (flask polymerization) White powdered polypropylene with a shape close to a perfect sphere 7.4
I got g.

CE is 181, K is 151, and I. I.
was 94.1% ρB was 0.263 g/cc.

As a result of step (B) (autoclave polymerization), 198 g of white powdery polypropylene was obtained.

CE is 5190, K is 173, and [η] of the polymer
is 1.71,I. I. is 93.1%, ρB is 0.417
g/cc.

The polypropylene particles were approximately spherical and had good particle fluidity.

Example 3 In step (A) of Reference Example 1, except that toluene was used instead of n-heptane, di-n-butyl ether was used instead of di-n-octyl ether, and 45 mmol of diethylaluminium monochloride was used. The same operation as in step (A) of Reference Example 1 was carried out to obtain a homogeneous toluene solution of titanium trichloride, and then the same operation as in step (B) of Reference Example 1 was carried out. As in Reference Example 1, a purple color was obtained. of finely divided titanium trichloride was obtained.

When this was used to polymerize propylene in the same manner as in step (B) of Example 1, 193 g of white powdery polypropylene was obtained.

CE was 5050, K was 168, and ρB of the polymer was 0.3639/cc.

The shape of the polymer was almost completely spherical, the particle size distribution was extremely narrow, and the particle fluidity was good.

Example 4 A homogeneous solution of titanium trichloride in toluene was obtained in the same manner as in Example 3 instead of step (A) of Reference Example 1, and the solution was heated at 40°C with stirring.
When the temperature was raised to 60 minutes and maintained at
A precipitate was observed.

Then, the temperature was raised to 90°C and held for 60 minutes, and the temperature was raised to (B) of Reference Example 1.
13.4g of purple fine granular titanium trichloride in the same manner as the process
I got it.

When polymerization was carried out in the same manner as in step (B) of Example 1 using this, 190 g of white powder polypropylene was obtained.
I got it.

CE is 4970, K is 166, and [η] of the polymer
is 1.56,I. I. is 94.2%, ρB is 0.365
g/cc.

Further, the shape of the polymer was almost completely spherical, the particle size distribution was extremely narrow, and the particle fluidity was also very good.

Examples 5 to 7 The same operations as in step (A) of Reference Example 1 were carried out except that the amounts of titanium tetrachloride, n-octyl ether, and diethylaluminium monochloride used in step (A) of Reference Example 1 were varied. A homogeneous solution of titanium chloride was obtained.

Next, in step (B) of Reference Example 1, the same precipitation operation as in step (B) of Reference Example 1 was performed, except that the temperature was raised to 90°C instead of 93°C and stirring was performed for 1 hour. In the same manner as in Example 1, a purple fine-grained titanium trichloride catalyst was obtained.

Using this, propylene was polymerized in the same manner as in step (A) of Example 1.

The results were as shown in Table-1.

*1 For raw material titanium tetrachloride Examples 8 to 10 In step (A) of Reference Example 1, as a solvent, toluene or xylene was used instead of n-heptane, and instead of di-n-octyl ether. The same operation as in step (A) of Reference Example 1 was carried out to prepare titanium trichloride in toluene or A homogeneous xylene solution was obtained, and then in step (B) of Reference Example 1, the temperature was changed to 90°C instead of 93°C.
Example 1 (B) except that the temperature was raised to ℃ and stirred for 1 hour.
The same precipitation operation as in step ) was carried out, and as in Reference Example 1, purple fine-grained titanium trichloride was obtained.

Using this, propylene was polymerized in the same manner as in step (A) of Example 1.

The results were as shown in Table-2.

[Brief explanation of drawings]

The drawing is a chart for explaining the effects of the present invention, and the curve in the drawing shows the particle size distribution of the polymer.

Claims (1)

[Claims] 1. Polymerization of α-olefin with solid titanium trichloride and general formula ALR'nX3-n (wherein R' is an alkyl group having 1 to 8 carbon atoms, and n is 1 to
3 in the presence of an organoaluminum compound represented by X represents a halogen atom), in which titanium tetrachloride is used as the solid titanium trichloride in the presence of ether, AlRnX3-n (wherein, R is a hydrocarbon group having 1 to 20 carbon atoms, and n is 1 to 3
, X is a halogen atom).
A method for producing an α-olefin polymer, which uses the following fine-grained purple solid titanium trichloride precipitated by contacting with a liberating agent in multiple stages at different temperatures.