JPS5856362B2 - Production method of titanium trichloride catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a titanium trichloride catalyst useful as a catalyst component for the stereoregular polymerization of α-olefins, and a method for producing the same. The present invention relates to a method for producing a titanium trichloride catalyst that is a stereoregular polymerization catalyst for α-olefins that provides high and uniform polymer particles.

Catalysts generally used for the stereoregular polymerization of α-olefins include halogenides of low-valent transition metal elements, such as α-type titanium trichloride and titanium tetrachloride obtained by reducing titanium tetrachloride with hydrogen. A eutectic of α-type titanium trichloride and aluminum chloride obtained by reducing the eutectic with aluminum, and a δ-type titanium trichloride obtained by grinding this eutectic are known.

Other methods for modifying titanium trichloride include adding metal halides, alkylaluminum compounds, halogenated hydrocarbons, ethers, esters, ketones, etc. and pulverizing them, or simply adding them. A method of adding a compound has been proposed.

For example, in JP-A-48-59185, α-type titanium trichloride is crushed into α-type titanium by adding a rogenated hydrocarbon, such as tetrachloride hydrocarbon, chloroform, dichloromethane, hexachloroethane, etc. A method for modifying titanium trichloride is described.

However, this method is not effective for titanium trichloride other than α-type titanium trichloride, requires pulverization, and requires complicated preparation of the catalyst, and also has problems with polymerization activity and stereoregular polymers. It is still not satisfactory in terms of production rate, etc.

Furthermore, a method of extracting and removing aluminum compounds by treating a reduced solid containing titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound with a complexing agent, and then treating it with titanium tetrachloride (Unexamined Japanese Patent Publication No. Showa 47-3447
8), a method of treatment with carbon tetrachloride (Japanese Unexamined Patent Publication No. 1983-
112289), or a method in which a reduced solid containing titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound is treated with a complexing agent and a hardened substance of carbon tetrachloride (JP-A-50-143790). Public bulletin) etc. are known.

However, the method of treatment with titanium tetrachloride is not economical because it requires a highly concentrated solution of expensive titanium tetrachloride.
Furthermore, the method using carbon tetrachloride has the advantage of using inexpensive carbon tetrachloride instead of expensive titanium tetrachloride;
Carbon tetrachloride tends to dissolve titanium trichloride, resulting in a low yield of titanium trichloride, and is not always satisfactory in terms of polymerization activity, stereoregular polymer formation rate, and polymer particle shape. do not have.

The present inventors have conducted extensive research to obtain a titanium trichloride catalyst that improves the drawbacks of these known titanium trichloride or titanium trichloride compositions. A titanium trichloride catalyst obtained by treating a reduced solid containing titanium trichloride obtained by reduction with a chlorinated hydrocarbon having 2 or more carbon atoms in the presence of a complexing agent and an aluminum trichloride-ether complex. The present invention was completed by discovering that titanium trichloride has extremely excellent performance when used as a catalyst for α-olefin polymerization.

That is, in the present invention, titanium tetrachloride is reduced with an organoaluminum compound, and the resulting product is reduced with a chlorinated hydrocarbon having 2 or more carbon atoms and 2 to 6 chlorine atoms in the presence of ether and an aluminum trichloride-ether complex. The gist of this invention is a method for producing a titanium trichloride catalyst, which is characterized by a treatment.

A reduced solid containing titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound (hereinafter simply referred to as reduced solid) used in the present invention.

) is a reduced solid with a complex composition that contains aluminum compounds and exhibits a brown to reddish-purple color.

The reduced solid obtained in this way uniformly contains an aluminum compound or a mixture or complex compound thereof, and this has some interaction with ether or a chlorinated hydrocarbon having two or more carbon atoms. It is presumed that this improves the catalyst performance.

Those commonly used as the above organoaluminum compounds have the general formula RnAlX2-n (where R is an alkyl group or an aryl group, and X is a rogene atom), and n is 1
Indicates an arbitrary number in the range of ≦n≦3.

), or a mixture or a complex compound thereof, particularly those having 1 to 18 carbon atoms, preferably 2 to 18 carbon atoms, such as trialkylaluminum, dialkylaluminum halide, monoalkylaluminum civalide, and alkyl aluminum sesquichloride. Particular preference is given to six alkyl aluminum compounds or mixtures or complexes thereof.

Specifically, examples of trialkyl aluminum include trimethylaluminum, triethylaluminum, and tributylaluminum, and examples of dialkylaluminum halides include dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, and diethylaluminium iodide. Examples of monoalkylaluminum cibarides include methylaluminum dichloride, ethylaluminum dichloride, butylaluminum dichloride, ethylaluminum dichloride, and ethylaluminum diiodide; examples of the alkylaluminum sesquihalides include ethylaluminum sesquichloride; In particular, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, or mixtures or complexes thereof, such as mixtures of diethylaluminium chloride and ethylaluminum dichloride, are industrially easy to obtain and have excellent effects. This is especially desirable because it shows

Reduction of titanium tetrachloride is usually carried out by adding 15% titanium tetrachloride to a solution of titanium tetrachloride dissolved in 12 aliphatic hydrocarbons having 5 carbon atoms.
This is carried out by dropping the organometallic compound or its solution at a temperature of 0° C. to +30° C. over a period of 30 minutes to 3 hours, but the reverse method may also be adopted.

The amount of organoaluminum compound used is usually 1 to 5 gram atoms of aluminum per gram atom of titanium.

Titanium tetrachloride is converted into diethylaluminum chloride (DE
AC) or a mixture of DEAC and ethylaluminum dichloride (EADC), the molar ratio is T
iCl4:DEAC=1:1~1:5 or Ti
Cl4:DEAC:EADC=1:1:0.
A suitable ratio is 1 to 1:4:1.2.

Note that the mixture of titanium tetrachloride and the organoaluminum compound may be further aged at a temperature of 20° C. to 50° C. for 1 to 3 hours, but this treatment is not necessarily required.

Next, the obtained reduced solid is separated by an appropriate method, washed with an inert solvent if necessary, and used as it is, or dried or heat-treated to obtain the reduced solid of the present invention.

The reduced solid thus obtained contains in a homogeneous state at least 0.2 gram atoms of aluminum or a mixture or complex thereof as aluminum per gram of titanium.

Next, the reduced solid thus obtained is treated in a slurry state with a chlorinated hydrocarbon having 2 or more carbon atoms and 2 to 6 chlorine atoms in the presence of ether and an aluminum trichloride-ether complex, A titanium trichloride catalyst of the present invention is obtained.

The chlorinated hydrocarbon and Citeha, hexachloroethane, pentachloroethane, tetrachloroethane, trichloroethane, dichloroethane, tetrachlorethylene, trichlorethylene, dichloroethylene, hexachlorofuropane, pentachloropropane, tetrachlorofuropane, Trichloropropane, dichloropropane, tetrachlorobutane, trichlorobutane, 'dichlorobutane, trichloropentane, dichloropentane, dichlorohexane, dichlorohebutane, dichlorooctane, dichlorocyclohexane, dichlorobenzene, trichlorobenzene, dichloropropene It is a chlorinated product of saturated or unsaturated aliphatic hydrocarbons, alicyclic hydrocarbons, or aromatic hydrocarbons such as trichloropropene and dichlorobutenat, and includes all isomers thereof.

Among these various chlorinated hydrocarbons, chlorinated aliphatic saturated hydrocarbons are effective, and among these, those with 2 to 8 carbon atoms are particularly effective, such as hexachloroethane, pentachloroethane, etc. , tetrachloroethane, trichloroethane, tetrachloroethylene, hexachloropropane, pentachloropropane, tetrachloropropane, trichloroethane, dichloropropane, and the like are particularly preferred.

The chlorinated hydrocarbon used may be one of these (or two).
It may be a mixture of more than one species.

This chlorinated hydrocarbon treatment is carried out by bringing the chlorinated hydrocarbon having two or more carbon atoms into contact with the above-mentioned reduced solid in a slurry state in the presence of ether and an aluminum trichloride-ether complex. adding the mixture of the chlorinated hydrocarbon, ether and the aluminum trichloride-ether complex or the mixture of the chlorinated hydrocarbon, the ether, the aluminum trichloride-ether complex and the inert solvent to an inert solvent containing reduced solids; The simplest method is to first treat the reduced solid with ether and then contact it with the chlorinated hydrocarbon and the aluminum trichloride-ether complex, or by first contacting the reduced solid with the chlorinated hydrocarbon. A method may also be adopted in which the aluminum trichloride-ether complex is brought into contact with ether and an aluminum trichloride-ether complex.

Further, as a method for bringing the reduced solid into contact with the chlorinated hydrocarbon, ether and/or aluminum trichloride-ether complex, the chlorinated hydrocarbon, ether and/or aluminum trichloride-ether complex or these and an inert solvent may be used. It is also possible to add a reduced solid or an inert solvent in which the reduced solid is dispersed to the mixture.

However, if the reduced solid is pulverized by adding the chlorinated hydrocarbon, ether, aluminum trichloride-ether complex and, if necessary, an inert solvent, the resulting titanium trichloride catalyst will have poor catalytic performance and will be finely powdered. This is undesirable because it gives an irregular α-olefin polymer.

For the treatment of chlorinated hydrocarbons with carbon numbers of 2 or more as described above,
There are optimum conditions depending on the properties, composition, etc. of the reduced solid, but in general, when carried out at low temperatures, it is necessary to carry out the treatment for a long time, and when carried out at high temperatures, a short time is sufficient.

For example, it can be carried out by maintaining at a temperature of 0 to 170°C for 5 minutes to 20 hours, preferably at a temperature of 20 to 150°C for 30 minutes to 20 hours, and more preferably at a temperature of 50 to 100°C for 1 to 10 hours. Although suitable, it is not necessary to limit the conditions to these.

The amount of chlorinated hydrocarbon having 2 or more carbon atoms, ether, and aluminum trichloride-ether complex is not particularly limited, but is 0.2 to 0.2 to 1 gram atom of titanium.
3.0 mol, preferably 0.4 to 2.0 mol, ether 0.1 to 2.5 mol, preferably 0.3 to 0.8 mol, aluminum trichloride-ether complex 0.05 to 3 mol ．．
A suitable amount is 0 mol, preferably 0.1 to 0.6 mol.

Next, when the reduced solid is first treated with ether and then treated with the numbered hydrocarbon and aluminum trichloride-ether complex, the contact with the ether is preferably carried out at a temperature of 0 to 120°C for 5 minutes to 8 hours. 3 at a temperature of 20-90'C
0 minutes to 3 hours, and then contact with the chlorinated hydrocarbon and aluminum trichloride-ether complex for 20 to 1 hour.
30 minutes to 20 hours at a temperature of 50°C, preferably 50 to 1
It is appropriate to carry out the reaction at a temperature of 00°C for 1 to 10 hours.

Also in this case, the amounts of ether, chlorinated hydrocarbon and aluminum trichloride-ether complex used are not particularly limited, but are usually 0.1 to 2.5 ether per gram atom of titanium.
mol, preferably 0.3 to 0.8 mol, chlorinated hydrocarbon 0.2 to 3.0 mol, preferably 0.4 to 2.0 mol, aluminum trichloride-ether complex 0.05 to 3 mol ．．
A suitable amount is 0 mol, preferably 0.1 to 0.6 mol.

Specifically, the ethers used in the present invention include diethyl ether, diisopropyl ether, di-n-butyl ether, diisobutyl ether, diisoamyl ether, di-2-ethylhexyl ether, di-2-ethylhebutyl ether, allyl ethyl ether,
Allyl butyl ether, diphenyl ether, anisole, phenethole, chloranisole, bromanisole, dimethoxybenzene, etc. are used.

Among them, ethers having 4 to 16 carbon atoms are preferred.

Inert solvents include hydrocarbons, for example aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cycloaliphatic hydrocarbons such as cyclohexane, cyclopentane, aromatic hydrocarbons such as benzene, toluene, etc., or mixtures thereof. Appropriate.

The aluminum trichloride-ether complex used in the present invention refers to a complex formed from 1 mol of aluminum trichloride and 1 mol of ether.

This complex is usually prepared by dispersing aluminum trichloride in a hydrocarbon solvent, then adding at least the same mole of ether to the aluminum trichloride at room temperature or higher, and stirring until the aluminum trichloride is completely dissolved. It can be obtained by

In addition, in the method of the present invention, it is also possible to add aluminum trichloride and ether to the system in which the reduced solid is treated with a complexing agent and a chlorinated hydrocarbon and bring the reduced solid into contact with the system. It is preferable to use one that has been prepared in advance.

The ether used here is not particularly limited, but aliphatic or aromatic ethers having 4 to 16 carbon atoms are generally easily available and desirable.

The titanium trichloride catalyst thus obtained is separated from the chlorinated hydrocarbon, ether, aluminum trichloride ether complex and inert solvent, washed with an inert solvent if necessary, and then dried as is or further dried. After that, it is brought into contact with an organoaluminum compound as a promoter by a conventional method and used as a catalyst for α-olefin polymerization.

The titanium trichloride catalyst obtained by the process of the invention comprises an aluminum compound or mixture or complex compound corresponding to 0.0001 to 0.2 gram atom of aluminum per gram atom of titanium and 0.005 to 0.05 per gram atom of titanium. from 0.2 mol to 0.2 mol of said chlorinated hydrocarbon and 0.
．． The catalyst composition has the best performance when it contains 0.005 to 0.2 moles of ether.

The titanium trichloride catalyst according to the present invention is made into a catalyst for α-olefin polymerization by contacting it with an organometallic compound normally used as a cocatalyst in a Ziegler type catalyst, such as monoalkylaluminum dichloride, dialkylaluminum monochloride, or trialkylaluminum. , and, if necessary, various compounds as a third component, such as the ethers and ethers used in the present invention, thiols, organic phosphorus-containing compounds, organic nitrogen-containing compounds, ketones,
A complexing agent such as esters may be added.

The α-olefin polymerization catalyst consisting of a titanium trichloride catalyst and an organoaluminum compound of the present invention includes propylene,
It is extremely excellent as a catalyst for homopolymerization or copolymerization of α-olefins such as phtento 4-methylpentene 1,
It has excellent polymerization activity in inert solvents, liquid monomers, or gas phase polymerization of α-olefins, has an extremely high production rate of stereoregular polymers, and has extremely excellent performance, such as the ability to obtain uniform particles. It is a useful catalyst.

Furthermore, as described below, when the titanium trichloride catalyst produced by the method of the present invention is used as a catalyst for producing an ethylene-propylene block copolymer, it provides superior effects compared to conventionally known catalysts.

That is, a propylene homopolymer is produced in the first stage,
In the method for producing an ethylene-propylene floc copolymer by reacting the propylene homopolymer with ethylene or ethylene and fluoropylene in the second stage, the titanium trichloride catalyst obtained by the method of the present invention is used, especially in the first stage. The tart index of the homopolypropylene obtained in the step reaction is in the range of 3 to 20, and the content of the block portion of the ethylene-propylene block copolymer obtained in the second step copolymerization reaction is 5 to 30. Weight%, ■Ethylene content in the block part is 20 to 90% by weight
When the reaction conditions are set so that the ethylene-propylene block copolymer is produced, there is very little atactic polymer produced as a by-product, and it has excellent rigidity and impact resistance, as well as low bulk density and average particle size. It exhibits great effects such as being able to obtain an ethylene-propylene block copolymer with excellent particle properties such as large size and narrow particle size distribution in high yield.

The present invention will be explained in more detail below using examples.

In addition, in the examples, for convenience, titanium tetrachloride was used as DEAC or DEA.
Although the description has been made using a reduced solid obtained by reduction with a mixture of C and EADC, the present invention is not limited thereto.

Example 1 A 2 t flask equipped with a stirrer was placed in a constant temperature water bath kept at 0°C, and 700 ml of purified hebutane and 250 ml of titanium tetrachloride were added and mixed.

Next, while keeping the temperature of this hebutane solution of titanium tetrachloride at 0°C, DEAC of 315r111 (titanium tetrachloride 1
corresponding to 1.1 mol), l 17rIL
#) A mixture consisting of EADC (corresponding to 0.5 mol per mol of titanium tetrachloride) and 400 ml of purified hebutane was mixed dropwise over a period of 3 hours.

After dropping, heat the contents while stirring and heat for 1 hour.
The temperature was increased to 5° C., and the mixture was further stirred at this temperature for 1 hour to obtain a reduced solid.

The resulting reduced solid was separated, washed with purified hebutane, and then dried under reduced pressure at 65°C for 30 minutes.

The reduced solid obtained here has a reddish-purple color, and the peak at 2θ-42,4° (β-type crystal) in the X-ray diffraction spectrum is higher than the peak at 2θ-51,3° (δ-type crystal). It's quite small.

Next, a suspension of this reduced solid 251 in 100 ml of purified heptane is prepared, and then an amount of di-n-butyl ether corresponding to 0.6 moles per gram atom of titanium in the reduced solid is added to the suspension. was added, stirred and mixed at 65°C for 1 hour, and further added 1 gram atom of titanium in the reduced solid.
A mole-equivalent amount of hexachloroethane and 0.3 mole of aluminum trichloride di-n-butyl ether complex, which had been prepared in advance in the same manner, were added, and the mixture was stirred at 80° C. for 5 hours to obtain a titanium trichloride catalyst.

The obtained titanium trichloride catalyst was further washed five times with 100 ml of purified hebutane and then dried at 65° C. for 30 minutes to obtain a titanium trichloride catalyst powder with a yield of 99% as titanium.

The titanium trichloride catalyst of the present invention thus obtained is
It contained an aluminum compound corresponding to 0.019 gram atoms of aluminum per gram atom of titanium, 0.025 moles of di-n-butyl ether, and 0.011 moles of hexachloroethane.

Next, a polymerization test was conducted on a polymerization catalyst using the titanium trichloride catalyst of the present invention.

After adding 100 rv of titanium trichloride catalyst and an amount of I) EAC corresponding to 4 moles per gram atom of titanium into a 1 t autoclave, 600 ml (standard conditions) of hydrogen were added and then 800 ml of liquid propylene were introduced. did.

Subsequently, the contents of the autoclave were heated to 68°C and polymerized for 30 minutes, after which unreacted propylene was removed and decatalyzed using a conventional method to obtain a bulk density of 0.45 V/CC.
Polypropylene powder 213r was obtained.

Therefore, the polymerization activity (number of polymers produced per 1z of catalyst, ie catalyst efficiency, hereinafter expressed as E) is 213
It was 0.

The melt flow rate of this polypropylene (Melt
Flow Rate ASTM D1238, hereinafter MF
) was 4.8.

In addition, this polypropylene was extracted with heptane using a Soxhlet extractor for 5 hours to extract heptane/insoluble matter (
As a result of measuring the HI (hereinafter referred to as HI), the value was 98%.

These results are shown in Table-1.

In addition, P, S, D, and index in the table are indices indicating the particle size distribution of the polymer powder, and are values calculated using the following formula.

Comparative Example 1 Completely the same as Example 1 except that the titanium trichloride catalyst used in Example 1 was replaced with a reduced solid that was not treated with hexachloroethane, di-normal butyl ether, and aluminum trichloride-di-normal butyl ether complex. Table 1 shows the results of a polymerization test conducted using the method described above.

As is clear from these results, the performance of the titanium trichloride catalyst is significantly improved by the treatment with hexachloroethane, etc. of the present invention.

Comparative Example 2 The reduced solid was treated in exactly the same manner as in Example 1, except that hexachloroethane and aluminum trichloride di-n-butyl ether complex were not used, and then a polymerization test was conducted. The results are shown in Table 1. .

As is clear from these results, it is important in the present invention to use hexachloroethane and aluminum trichloride di-n-butyl ether complex.

Comparative Example 3 Example 1 except that hexachloroethane was not used in Example 1 (after treating the reduced solid in the same manner as in Example 1),
The results of the polymerization test are shown in Table 1.

Comparative Example 4 When the reduced solid was treated in exactly the same manner as in Example 1 except that di-n-butyl ether and aluminum trichloride-din-n-butyl ether complex were not used, the reduced solid became lumpy.

Next, in Example 1, hexachloroethane treatment was performed without using ether, at a treatment temperature of 35° C., and for a treatment time of 16 hours, to obtain a titanium trichloride catalyst.

Next, a polymerization test was conducted using this catalyst in the same manner as in Example 1, and the result was that E=400. A powdered polypropylene with HI-94% was obtained.

The above results show that it is important for the titanium trichloride catalyst of the present invention to treat the reduced solid with hexachloroethane in the presence of ether and aluminum trichloride di-n-butyl ether lead.

Comparative Example 5 Reduced solid 25f obtained in Example 1 and n-heftane 10
Di-n-butyl ether equivalent to 0.6 mol per gram atom of titanium in the reduced solid was added to 0 ml of the suspension, mixed and stirred at 65°C for 1 hour, and then heated to remove n-hebutane by evaporation. A treated solid was obtained.

This treated solid was collected using a stainless steel pole with a diameter of 12 mm.
Put it in a 300ml stainless steel container containing 0 pieces,
Further, 1 mol of hexachloroethane and 0.3 mol of aluminum trichloride di-n-butyl ether complex were added per gram atom of titanium, and vibration milling was carried out for 15 hours at room temperature.

The obtained solid was adhesive and adhered to the stainless steel pole and the inner wall of the container.

Using this solid, a propylene polymerization test was conducted using the same polymerization method as in Example 1.

The results are shown below, and it can be seen that the catalytic performance was significantly inferior to that of Example 1, in which contact was carried out by the slurry method, or the obtained polymer was fine powder and irregular in size.

E=290. HI-89%, MFR=9.5, bulk density-0.27? /CC, PSD index-1,
08 Titanium 1f in ether reduced solid? Number of moles of ether per atom Number of moles of hexachloroethane per atom of titanium 11 in the reduced solid Number of moles of aluminum trichloride di-n-butyl ether complex per z atom of titanium in the reduced solid Example 2 In Example 1, A titanium trichloride catalyst was produced in exactly the same manner as in Example 1, except that titanium chloride was reduced using only DEAC.

The yield was 99% as titanium.

Next, using this titanium trichloride catalyst, a propylene polymerization test was conducted in the same manner as in Example 1, and as a result, E = 201
0°HI=98%, MFR=5.0, bulk density -〇, 4
A polypropylene powder of 6☆☆z/CC was obtained.

Examples 3 to 13 Trichloride was treated in exactly the same manner as in Example 1, except that the chlorinated hydrocarbons shown in Table 2 were used instead of the hexachloroethane used to treat the reduced solid. Table 2 shows the results of manufacturing titanium catalysts and conducting polymerization tests.

Examples 14-15 Instead of the aluminum trichloride di-n-butyl ether complex used in Example 1, aluminum trichloride-diethyl ether complex (AICl a-Et20) or aluminum trichloride-diphenyl ether complex (Al
A titanium trichloride catalyst was produced in exactly the same manner as in Example 1, except that Cl2-Ph20) was used, and a polymerization test was conducted.

The results are shown in Table 3.

Example 16 In the polymerization test of Example 10 using the titanium trichloride catalyst of Example 1, in addition to 800 ml of liquid propylene, 5.3 Z of ethylene was injected little by little intermittently during the 30 minute polymerization. Except for the above, a polymerization test was carried out in the same manner as in Example 1, and an ethylene-propylene copolymer 255z containing 2.0% of ethylene moiety was obtained.

That is, the polymerization activity was 2550, and the HI in the obtained copolymer was 94%.

Examples 17-20 After adding 50 μ of the titanium trichloride catalyst obtained in Example 1 and DEAC in an amount equivalent to 5 moles per 1 gram atom of titanium to an autoclave under a nitrogen gas atmosphere, 9
00rnl of hydrogen were added and then 800ml of liquid propylene were introduced.

The contents of the autoclave were then heated to 68°C and heated to 40°C.
Polymerization was carried out for minutes.

After that, excess unreacted propylene was discharged, and the pressure of the -tan autoclave was increased to 9 kl? /crA gauge pressure, a mixed gas of ethylene and propylene prepared in advance was supplied, and polymerization was carried out at 60° C. and 2 kMc4 gauge pressure for a predetermined period of time.

After that, unreacted gas was released, and a mixed solution of Impropatool and hebutane (50% by weight, 150% by weight) was added and heated to 66°C.
After removing the catalyst for 1 hour, the solid ethylene-propylene block copolymer produced was separated from the impropanol-butane mixture, washed repeatedly with the impropanol-butane mixture, and then dried.

On the other hand, an amorphous atactic polymer was recovered from the separated impropanol-hebutane mixture.

Copolymerization conditions and composition and physical properties of the obtained copolymer Table 4
Shown below.

As is clear from the table, the copolymerization reaction performed using the titanium trichloride catalyst obtained by the method of the present invention has a higher catalytic activity than the copolymerization method using the conventionally known polymerization catalyst (Comparative Examples 6 to 9). is much higher, and the amount of by-product amorphous atactic polymer can be significantly reduced.

Moreover, the obtained powdered ethylene-propylene block copolymer is characterized by having a large bulk density and a large average particle diameter, and that the particles are uniformly arranged.

Furthermore, it is physically excellent, particularly in both rigidity and impact resistance.

Comparative Examples 6 to 9 Examples 17 to 9 except that instead of the titanium trichloride catalyst used in Examples 17 to 20, AA grade titanium trichloride catalyst 200 cm manufactured by Toyo Stouffer Co., Ltd. was used and the amount of hydrogen was 600 m1. Polymerization was carried out in the same manner as No. 20, and the results are shown in Table 4.

The symbols used in Table 4 have the following meanings and are expressed in the following units.

E: Number of grams of copolymer produced per 1z of polymerization catalyst (?/y-cat, ) Ec: Number of grams of ethylene-propylene block portion produced per 11 catalysts in the copolymerization reaction [y/g] c.
at, ) Ec/Time: In a 1 hour copolymerization reaction, catalyst 1
Number of grams of ethylene-propylene block moieties produced per unit (?/?-cat, time) C-value: Content of ethylene-propylene block moieties in the copolymer produced by the second stage copolymerization [weight] %] G-value: Content of ethylene in the ethylene-propylene block part [wt%] Ethylene content: Total ethylene content contained in the copolymer, determined by IR spectrum [wt%] HI: Copolymer Remaining amount [weight %] when extracted with boiling heptane using a Soxhlet extractor for 5 hours M: Melt index, ASTM D1238 [J/10 minutes] Stiffness: ASTM D-747 (kg/c4)
Izotsu impact strength: ASTM D-256 [kg・
CrIL/cd] However, the physical properties were measured using a test piece obtained by forming a press sheet with three thicknesses.

Claims (1)

[Claims] 1. Reducing titanium tetrachloride with an organoaluminum compound,
A titanium trichloride catalyst characterized in that the obtained product is treated in a slurry state with a chlorinated hydrocarbon having 2 or more carbon atoms and 2 to 6 chlorine atoms in the presence of ether and an aluminum trichloride-ether complex. Manufacturing method. 2. The chlorinated hydrocarbon is selected from the group consisting of hexachloroethane, pentachloroethane, tetrachloroethane, trichloroethane, tetrachlorethylene, hexachloropropane, pentachloropropane, tetrachloropropane, trichloropropane and dichloropropane. A method according to claim 1.