JP2690219B2 - Method for producing propylene ethylene copolymer particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for obtaining propylene-ethylene copolymer particles having a high bulk density and excellent fluidity in a high yield.

[0002]

2. Description of the Related Art In recent years, ethylene propylene rubber (hereinafter referred to as
EPR), ethylene propylene terpolymer (hereinafter abbreviated as EPDM) and EPR or EP
An olefin resin having flexibility such as a thermoplastic elastomer which is a blend of DM and polypropylene,
Widely used in automobile parts, electric wire field, home appliances parts, etc.

Generally, EPR and EPDM are produced by a solution polymerization method using a vanadium catalyst, and there is a problem that a complicated process is required in addition to low polymerization activity. Regarding the thermoplastic elastomer, the above-mentioned EP
Since it is manufactured through a blending process of R or EPDM and polypropylene, there is a drawback that the process becomes more complicated.

JP-A-55-118910 proposes an attempt to recover a copolymer having a large ethylene content of 20 to 60 mol% in the form of particles by increasing the molecular weight. However, the bulk specific gravity of the obtained copolymer particles is at most about 0.20 g / cm ³ , and the copolymer particles having such a low bulk specific gravity are inferior in fluidity and cause the blockage of the line in the production process. And it is difficult to transport, which is not preferable.

On the other hand, Japanese Patent Laid-Open No. 56-151713,
58-213012 and 59-38219.
In the publication, in the production of a propylene-ethylene block copolymer, a method of simultaneously improving the polymerization activity and the particle fluidity by carrying out vapor-phase copolymerization of propylene and ethylene in the presence of aluminum alkoxide. It is disclosed. According to this method, copolymer particles having excellent fluidity can be produced, but the polymerization activity of the catalyst is not sufficiently high. Therefore, a method for producing copolymer particles having excellent fluidity with high polymerization activity is desired.

[0006]

In view of the above problems, the present inventors have studied for many years on a method for producing propylene ethylene copolymer particles having excellent fluidity and excellent catalyst polymerization activity. The present invention has been completed by finding a method of previously mixing alkoxide and an electron donor and then performing copolymerization in the presence of the mixture.

That is, the present invention provides an olefin in the presence of a catalyst containing a titanium halogen compound (hereinafter, the term "titanium compound" means "titanium halogen compound") and an organoaluminum compound. the prepolymerization-obtained titanium-containing polyolefin and an organic propylene as the polymerization in the presence of an aluminum compound homopolymerized, then the general formula _{R n Al (OR ') 3} -n ( where, R represents an alkyl group, an aryl A group or a halogen atom, R ′ is an alkyl group or an aryl group,
n is an integer of 0 to 2. ) A mixture of an aluminum alkoxide and an electron donor shown in advance) is added to the polymerization system, and ethylene or ethylene and propylene are introduced into the polymerization system to carry out random copolymerization. It is a method for producing polymer particles.

In the present invention, known titanium compounds and organoaluminum compounds used for ordinary olefin polymerization are used without any limitation.

As the titanium compound, α, β, γ, or δ-titanium trichloride can be used, and among them, for example, JP-A-47-34478, 50-126590, and 5-126.
0-114394, 50-93888, 50-12
3091, 50-74594, 50-10419
1, 50-98489, 51-136625, 5
The highly active titanium compounds prepared by the methods described in JP-A Nos. 2-30888 and 52-35283 are preferably used.

Also, a titanium compound supported on a carrier such as magnesium chloride can be preferably used. For example, JP-A-56-155206 and JP-A-56-13680.
6, the same 57-34103, the same 58-8706, the same 58-
83006, 58-138708, 58-1837
09, 59-206408, 59-219311,
60-1208, 60-81209, 60-18
6508, 60-192708, 61-21130.
9, 61-271304, 62-15209, 6
2-11706, 62-72702, 62-104
A titanium compound supported on a carrier such as magnesium chloride prepared by the method shown in 810 etc. is adopted.

As the organoaluminum compound, those generally used in combination with a titanium compound for polymerizing an olefin can be used without any limitation. For example, diethyl aluminum chloride, ethyl aluminum sesquichloride,
Examples include alkyl aluminum halides such as ethyl aluminum dichloride; trialkyl aluminums such as triethyl aluminum and triisobutyl aluminum; alkyl aluminum hydrides such as diethyl aluminum hydride and alkyl aluminums such as alkylaluminoxane. These organoaluminum compounds can be used alone or in combination of two or more.

In the main polymerization, in order to obtain a copolymer particle having excellent fluidity, the olefin is prepolymerized in the presence of the titanium compound and the organoaluminum compound.

The amount of the organoaluminum compound used in the prepolymerization is such that Al / Ti relative to Ti atoms in the titanium compound.
(Molar ratio) 0.01 to 100, preferably 0.1 to
Twenty.

Examples of olefins used in the prepolymerization include propylene, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene, and the like. These can be used alone or as a mixture. It is also possible to employ a method of prepolymerizing the same or different olefins in multiple stages. The prepolymerization amount of the olefin is 0.1 to 100 g per 1 g of the titanium compound, and preferably 0.1.
It is in the range of 5 to 50 g.

For the prepolymerization, it is usually preferable to apply solution polymerization, and as the solvent, a saturated aliphatic hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene may be used alone, or these may be used. Can be mixed and used.

In the prepolymerization, in order to further improve the fluidity of the copolymer particles produced in the subsequent main polymerization,
An electron donor can be added. As the electron donor, compounds known to be used for olefin polymerization can be used without any limitation. Specifically, it can be selected from ethers, amines, amides, esters, sulfur compounds, phosphorus compounds, nitriles, carboxylic acids, acid anhydrides, organic silicon compounds, halogen compounds and the like.

Other conditions in the prepolymerization, for example,
The temperature, pressure and time are not particularly limited as long as the effects of the present invention are not impaired, and may be appropriately determined.

The prepolymerization may be carried out batchwise, semi-batchly or continuously. After completion of the prepolymerization, the produced titanium-containing polyolefin may be washed with a solvent such as the saturated aliphatic hydrocarbon or aromatic hydrocarbon. preferable.

After the preliminary polymerization, main polymerization is carried out. The main polymerization is carried out in the presence of the titanium-containing polyolefin obtained by the above preliminary polymerization and the organoaluminum compound. When a new organoaluminum compound is added during the main polymerization, the organoaluminum compound that can be used in the preliminary polymerization can be used without any limitation.

In this polymerization, propylene homopolymerization is followed by copolymerization of ethylene and propylene. The important point in the present invention is that the copolymerization of propylene and ethylene is represented by the following general formula R _n Al (OR '). _3-n (wherein R is an alkyl group, an aryl group, or a halogen atom, R ′ is an alkyl group or an aryl group, and n is an integer of 0 to 2) and an aluminum alkoxide. It is carried out in the presence of a premixed electron donor.

Specific examples of the aluminum alkoxide represented by the above general formula include dimethyl aluminum methoxide, dimethyl aluminum ethoxide, dimethyl aluminum isopropoxide, diethyl aluminum methoxide, diethyl aluminum ethoxide, diethyl aluminum n-butoxide. , Diethyl aluminum isobutoxide, diethyl aluminum t-butoxide, diethyl aluminum octoxide, diethyl aluminum phenoxide, ethyl aluminum diethoxide, diisobutyl aluminum ethoxide, ethyl aluminum chloride monoethoxide, ethyl aluminum bromide monoethoxide, aluminum triethoxide. , Aluminum tributoxide and the like.

As the electron donor in the present invention, known electron donors used for conventional olefin polymerization can be used without any limitation. Specific examples of the electron donor in the present invention include methanol, ethanol, propanol, pentanol, hexanol, octanol,
Alcohols such as isopropyl alcohol; phenols such as phenol, cresol, cumylphenol, xylenol, naphthol; ketones such as acetone, methyl ethyl ketone, acetophenone, benzophenone; aldehydes such as acetaldehyde, propionaldehyde, benzaldehyde; methyl formate, acetic acid Methyl, ethyl acetate, vinyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, ethyl valerate, ethyl stearate, ethyl acrylate, methyl methacrylate, ethyl benzoate, methyl toluate, methyl anisate, Organic acid esters such as ethyl phthalate, methyl carbonate, butyrolactone; silicic acid esters such as ethyl silicate and phenyltriethoxysilane; methyl ether, ethyl Ether, isopropyl ether, isoamyl ether, tetrahydrofuran, anisole,
Ethers such as diethylene glycol dimethyl ether; oxygen-containing electron donors such as amides such as acetic acid amide, benzoic acid amide, and maleic acid amide: amines such as methylamine, ethylamine, piperidine, pyridine, aniline; acetonitrile, benzonitrile And the like; nitrogen-containing electron donors such as isocyanate: sulfur-containing electron donors: and phosphorus-containing electron donors.

Among them, organic acid esters such as methyl methacrylate, ethers such as diethylene glycol dimethyl ether, and silicate esters such as ethyl silicate are preferably used.

In the present invention, the above-mentioned aluminum alkoxide and the electron donor are pre-mixed before being added to the polymerization system, whereby the polymerization activity of the catalyst is improved, and particularly the activity sustainability is improved. It is not preferable to add the aluminum alkoxide and the electron donor individually to the polymerization system because the effects of the present invention cannot be obtained.

As the conditions for contacting the aluminum alkoxide with the electron donor, the temperature can be selected from the range of -100 to 100 ° C, and the temperature of 0 to 40 ° C is particularly preferable. The contact time is not particularly limited, but is preferably in the range of 30 minutes to 6 hours. The two components are
Respectively inert hydrocarbons, such as propane, butane,
It is preferably diluted with a medium such as pentane, hexane, heptane, decane or cyclohexane.

The addition amount of the aluminum alkoxide and the electron donor added to the polymerization system is such that the aluminum alkoxide is 0.01 to 10 mol, and further 0.1 to 1 mol, based on the organoaluminum compound used in the main polymerization. On the other hand, the electron donor is preferably 0.001 to 10 mol, and more preferably 0.01 to 1 mol with respect to the organoaluminum compound. Therefore, the mixing ratio of these two components may be appropriately determined from the amount added to the above-mentioned polymerization system, and is preferably in the range of 0.01 to 1 in terms of the electron donor / aluminum alkoxide molar ratio.

As the organoaluminum compound used in the main polymerization, those used in the above-mentioned prepolymerization can be used. The amount of the organic aluminum compound used is Al / Ti (molar ratio) based on the titanium atom in the titanium-containing polyolefin.
It is 1 to 5000, preferably 1 to 500.

In the present invention, in order to improve the fluidity of the obtained copolymer particles, homopolymerization of propylene is carried out prior to the copolymerization of propylene and ethylene. A mixture of the above-mentioned aluminum alkoxide and an electron donor is added to the polymerization system after the homopolymerization of propylene and before the copolymerization of propylene and ethylene.

The presence of the above-mentioned aluminum alkoxide and electron donor is not essential in the polymerization of propylene.

The polymerization ratio of propylene is 1 to 90 parts by weight with respect to the total amount of polymerization, and may be appropriately determined according to the physical properties of the obtained copolymer particles. That is, when flexibility is required, the smaller the polymerization amount of propylene is, the more preferable. When higher strength and high hardness are required, the polymerization amount may be increased.

In the polymerization of propylene, it is preferable to carry out homopolymerization of propylene substantially, but other olefins such as ethylene, 1-butene and 3-methyl-1.
-Butene, 4-methyl-1-pentene, 1-hexene and the like may be contained at 5 mol% or less.

The polymerization temperature of propylene is 0.
To 100 ° C is preferable, and generally 40 to 80 ° C.
Range. Hydrogen may be allowed to coexist as a molecular weight regulator. The polymerization may be any of slurry polymerization using propylene itself as a solvent, gas phase polymerization, solution polymerization and the like. The polymerization system may be a batch system, a semi-batch system, or a continuous system, and it is also possible to carry out the polymerization in two or more stages under different conditions.

In the polymerization of propylene, an electron donor can be added in order to improve the stereoregularity of the polymer to be produced, and the kind thereof can be those described above.

The copolymerization of propylene and ethylene is then carried out in the presence of the premixed mixture of aluminum alkoxide and electron donor described above. Copolymerization of propylene and ethylene can be carried out in the gas phase, but since the amount of residual aluminum in the obtained propylene-ethylene copolymer can be reduced, slurry polymerization is carried out using propylene itself as a medium. It is preferable. In this case, in addition to the propylene medium, a small amount of inert hydrocarbon may be included to dilute the catalyst components.

The composition of propylene and ethylene is adjusted so that the proportions based on the respective monomer units are 20 to 80 mol% and 80 to 20 mol% in consideration of the physical properties of the copolymer. The molar ratio may be appropriately determined within the range of 95/5 to 50/50.

For copolymerization of propylene and ethylene, other olefins such as 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene and the like can be used.
The content may be less than or equal to mol%.

The polymerization temperature is preferably in the range of 0 to 100 ° C, and generally in the range of 40 to 80 ° C. Hydrogen can be allowed to coexist as a molecular weight modifier, but a larger molecular weight is preferable in view of the particle fluidity of the copolymer produced. The polymerization system may be a batch system, a semi-batch system, or a continuous system. Furthermore, a method of carrying out the polymerization in two or more stages under different conditions, for example, after performing a polymerization with a low ethylene composition in the first stage, A method of carrying out polymerization with a high ethylene composition, a method of changing the hydrogen concentration in the first stage or the second stage, and the like can also be adopted. The polymerization time may be appropriately determined from the polymerization temperature and the polymerization amount. At the end of the main polymerization, the copolymer particles and unreacted liquid propylene and ethylene are separated.

In the liquid propylene and ethylene, the aluminum component added to the polymerization system is dissolved, and the weather resistance when the product is to be separated so that the adhesion of the aluminum component to the copolymer is reduced. Therefore, it is generally preferable to perform the following operation.

(A) The polymer slurry is passed through a liquid cyclone, most of the liquid propylene containing an aluminum component is recirculated to the polymerization tank, and the slurry in which the copolymer particles are concentrated is sent to a flash tank or an evaporation tank and liquid propylene is supplied. ,
And a method of evaporating an inert hydrocarbon solvent and the like.

(B) The polymer slurry was added from the upper part of the countercurrent washing tower, and new liquid propylene or carbon number 7 was added from the lower part.
The following method of supplying inert hydrocarbons that are relatively easily evaporated and washing and separating the copolymer particles while precipitating them.

(C) A method in which the entire amount of the polymer slurry is sent to an evaporation tank, flushed, washed with an inert hydrocarbon solvent having a carbon number of 7 or less or liquid propylene, and then the liquid portion is separated.

The copolymer particles obtained after the separation can be added with various additives and molding aids used in conventional polyolefins.

The propylene-ethylene copolymer particles obtained in the present invention can be molded into various shapes by various molding methods such as injection molding, extrusion molding and press molding.

Further, the copolymer particles of the present invention can be blended with various polymers such as polyolefin, and a graft reaction or the like can be performed.

[0045]

According to the present invention, the copolymerization of propylene and ethylene can be stably produced with high productivity while maintaining good fluidity without causing sticking and mutual sticking of particles.

Further, the copolymerization of propylene and ethylene is carried out by a slurry polymerization using propylene itself as a medium, and then the medium is separated, whereby the residual amount of the aluminum component in the copolymer can be reduced. Therefore, a high quality copolymer having excellent weather resistance can be produced.

[0047]

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

The measuring method used in the following examples will be described.

1) Ethylene content As for the ethylene content, JEOL GSX-270 was used.
Determined using ¹³ C-NMR.

2) Bulk Specific Gravity It was carried out according to JIS K6721 (1977).

3) Angle of repose “Powder physical properties measurement method” (written by Sohachiro Hayakawa), page 97.
That is, an inner diameter 68 having an outlet with a diameter of 10 mm in the center of the bottom
mm in a cylindrical container of 48 mm in height and 50 on the cylindrical container.
Drop the copolymer particles from the funnel installed at the height of mm,
After filling the cylindrical container, the outlet was opened to allow the copolymer particles in a static state to flow out, and the inclination of the slope of the powder layer remaining in the container was measured as the angle of repose.

4) Average particle size openings 75, 125, 250, 355, 500, 71
About 10 g of the copolymer particles were loaded into a 0,1180 μm sieve, and the particles were classified by a sieve shaker for 10 minutes to obtain an average particle diameter.

5) Weight average molecular weight It was measured by gel permeation chromatography. The measurement was carried out at 135 ° C. using GPC-150 manufactured by Waters Co., using orthodichlorobenzene as a solvent. The column used was Tosoh TSK gel GMH
6-HT, gel size 10-15 μm. The calibration curve has a weight average molecular weight of 950, 290 as a standard sample.
It was prepared using 0, 10,000, 50,000, 49.8 million, 2.7 million and 6.75 million polystyrene.

6) Room-temperature heptane-soluble component Approximately 1 g of the copolymer particles was added to n-heptane-1 at room temperature (23 ° C.).
After adding to 00 ml and stirring at 23 ° C. for 30 minutes, the mixture was filtered and the n-heptane solution was completely evaporated to obtain a soluble content.

7) Hardness A test piece was prepared according to JIS K6301 and measured using an A type tester.

8) Measurement of residual aluminum amount Using a fully automatic fluorescent X-ray analyzer system 3080 manufactured by Rigaku Denki Kogyo Co., Ltd., the obtained copolymer particles were press-molded and then measured.

Example 1 (Preliminary Polymerization) A glass autoclave reactor having an internal volume of 1 liter equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Reactor temperature 2
Keep at 0 ℃, diethyl aluminum chloride 14.5
After adding 1 mmol of titanium trichloride ("TOS-17" manufactured by Marubeni Solvay Chemical Co., Ltd.), propylene was continuously introduced into the reactor for 1 hour so that the amount of propylene was 3 g per 1 g of the catalyst. The temperature during this period was kept at 20 ° C. After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed four times with purified heptane. As a result of the analysis, 2.9 g of propylene was polymerized per 1 g of the catalyst.

(Preparation of Aluminum Alkoxide and Contact Mixture with Electron Donor) A glass one-liter three-necked flask equipped with a stirrer and having an internal volume of 1 liter was replaced with nitrogen gas and diluted with n-heptane. After charging triethylaluminum, 2 equivalents of ethanol diluted with n-heptane was added dropwise at room temperature to triethylaluminum. Ethyl aluminum diethoxide was prepared by reacting at 60 ° C. for 30 minutes.

500 ml of a 1 mmol / ml n-heptane solution of the above-prepared ethyl aluminum diethoxide.
15 ml of a 1 mmol / ml n-heptane solution of methyl methacrylate was added to and the mixture was contacted at 40 ° C. for 1 hour.

(Main Polymerization) Internal volume equipped with a stirrer 300
After fully replacing the liter of stainless steel autoclave reactor with nitrogen gas, 200 liters of liquid propylene and 108.6 mm of diethylaluminum chloride were used.
Then, the temperature inside the reactor was raised to 70 ° C., and 18.1 mmol of titanium-containing polypropylene obtained by preliminary polymerization as titanium trichloride was added under a nitrogen gas atmosphere.
Polymerization of propylene was carried out at 70 ° C. for 20 minutes. In another experiment, only propylene was polymerized under the above conditions and the polymer was recovered. As a result, 330 g of propylene was polymerized per 1 g of the catalyst.

The mixture of ethyl aluminum diethoxide and methyl methacrylate prepared above was added in an amount of 76.0 mmol as ethyl aluminum diethoxide and 2.3 mmol as methyl methacrylate, and the temperature inside the reactor was lowered to 55 ° C. Ethylene was supplied and charged so that the ethylene gas concentration was 10 mol%. The ethylene gas concentration was continuously supplied so as to be 10 mol%, and propylene and ethylene were copolymerized at 55 ° C. for 120 minutes. No hydrogen was used in the main polymerization step. The polymer slurry was passed through a liquid cyclone, liquid propylene was returned to the polymerization tank, the copolymer particles were sent to a flash tank to evaporate the liquid propylene, and white, free-flowing copolymer particles were obtained. Adhesion of particles in the polymerization tank and to the stirring blade,
And there was no mutual adhesion between the particles. Yield is 33.6k
g, and the polymerization ratio of all polymers is 8400 g / g-ca.
t. The results are shown in Tables 1 and 2. The amount of residual aluminum in the copolymer particles was 101 ppm.

Examples 2 to 10 The same operations as in Example 1 were carried out except that the type and addition amount of ethylaluminum diethoxide and the electron donor in Example 1 were changed as shown in Table 3. . The results are shown in Tables 1 and 2.

Examples 11 to 12 In the propylene polymerization of the main polymerization of Example 1, the same operation as in Example 1 was performed except that the polymerization amount was changed as shown in Table 1. The polymerization amount was controlled by changing the polymerization time. In Example 11, polymerization was performed at 70 ° C. for 40 minutes, and in Example 12, polymerization was performed at 70 ° C. for 90 minutes. Table 1 shows the results
And Table 2.

Examples 13 to 14 In the copolymerization of propylene and ethylene in the main polymerization of Example 1, the same operation as in Example 1 was carried out except that the ethylene concentration was changed as shown in Table 1. The results are shown in Tables 1 and 2.

Examples 15 to 16 In the copolymerization of propylene and ethylene in the main polymerization of Example 1, the same operation as in Example 1 was carried out except that the hydrogen concentration was changed as shown in Table 1. The results are shown in Tables 1 and 2.

Example 17 (Preparation of Titanium Component) Preparation of the titanium component was carried out according to JP-A-58.
It was carried out according to the method of Example 1 of JP-A-83006.
As a result of analysis, the obtained solid titanium compound was titanium 2.
1% by weight, chlorine 57.0% by weight, magnesium 18.0
% By weight and 21.9% by weight of diisobutyl phthalate.

(Preliminary Polymerization) A glass autoclave reactor having an internal volume of 1 liter equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Keep the temperature inside the reactor at 20 ℃ and
mmol, diphenyldimethoxysilane 10 mmol,
After charging 50 mmol of ethyl iodide and 5 mmol of a solid titanium catalyst component in terms of titanium atom, propylene was continuously introduced into the reactor for 1 hour so that the amount of propylene was 3 g per 1 g of the catalyst. The temperature during this period was kept at 20 ° C.
After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed four times with purified heptane. As a result of the analysis, 3.0 g of propylene was polymerized per 1 g of the catalyst.

(Main polymerization) Internal volume 300 equipped with a stirrer
After fully replacing the liter of a stainless steel autoclave reactor with nitrogen gas, 200 liters of liquid propylene was charged so that the hydrogen gas concentration was 0.2 mol%. After adding 164 mmol of triethylaluminum and 164 mmol of diphenyldimethoxysilane and raising the internal temperature of the reactor to 70 ° C., the titanium-containing polypropylene obtained by the prepolymerization was converted to a titanium atom content of 0.66 mmo.
1 was added under a nitrogen gas atmosphere. Polymerization of propylene was carried out at 55 ° C for 15 minutes. Unreacted monomer was purged and titanium-containing polymer particles were obtained under a nitrogen gas atmosphere.
As a result of separately confirming in the same experiment, 720 g of propylene was polymerized per 1 g of the catalyst.

After the temperature in the polymerization tank was set to 55 ° C., the mixture of ethylaluminum diethoxide and methyl methacrylate prepared in Example 1 was charged in an amount of 115 mmol in terms of ethylaluminum diethoxide. Ethylene was charged so as to have a gas concentration of 25 mol%, and ethylene gas was continuously fed so that the gas concentration was 25 mol%, and propylene and ethylene were copolymerized at 55 ° C. for 120 minutes. The same flash operation as in Example 1 was performed to obtain white free-flowing copolymer particles. There was no adhesion of particles to the inside of the polymerization tank or to the stirring blade, and no mutual adhesion between particles. The yield was 22.5 kg, and the polymerization ratio of all polymers was 15000 g / g-cat. The results are shown in Tables 1 and 2.

Example 18 After completion of the main polymerization of Example 1, the polymer slurry was sent to the upper part of the countercurrent washing tower, and new liquid propylene was supplied from the lower part to wash and separate the polymer while precipitating the copolymer. The particles were obtained. The amount of residual aluminum in the copolymer particles is 98 p
pm.

Example 19 After the completion of the main polymerization of Example 1, the whole amount of the polymer slurry was sent to an evaporation tank to evaporate propylene and then washed with fresh liquid propylene to separate only the liquid and copolymer particles Got The amount of residual aluminum in the copolymer particles is 114 pp
m.

Comparative Example 1 In the copolymerization of propylene and ethylene in the main polymerization of Example 1, the same operation as in Example 1 was carried out except that the mixture of ethylaluminum diethoxide and the electron donor was not added. It was The results are shown in Tables 1 and 2.

Comparative Example 2 The copolymerization of propylene and ethylene in the main polymerization of Example 1 was carried out except that ethylaluminum diethoxide and an electron donor were not mixed in advance and each was separately fed into a polymerization tank. The same operation as in Example 1 was performed. The heat of polymerization disappeared 60 minutes after the initiation of the copolymerization. The results are shown in Tables 1 and 2. Comparative Example 3 In the copolymerization of propylene and ethylene in the main polymerization of Example 1, a premixed mixture of diethyl aluminum chloride and an electron donor was used instead of the premixed mixture of ethyl aluminum diethoxide and an electron donor. The same operation as in Example 1 was performed. The heat of polymerization disappeared 30 minutes after the initiation of the copolymerization. The results are shown in Tables 1 and 2.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a flowchart of a manufacturing method of the present invention.

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Claims (1)

(57) [Claims] 1. A titanium-containing polyolefin obtained by prepolymerizing an olefin in the presence of a catalyst containing a titanium halogen compound and an organoaluminum compound, and homopolymerization of propylene as a main polymerization in the presence of an organoaluminum compound, and then general polymerization. wherein _{R n Al (oR ') 3} -n ( where, R is an alkyl group, an aryl group or a halogen atom,, R' is an alkyl group or an aryl group,
n is an integer of 0 to 2. ) A mixture of an aluminum alkoxide and an electron donor shown in advance) is added to the polymerization system, and ethylene or ethylene and propylene are introduced into the polymerization system to carry out random copolymerization. Method for producing polymer particles.