JPH0588248B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to continuous slurry polymerization of alpha-olefins. More specifically, during the slurry polymerization process of α-olefin using a Ziegler-Natsuta catalyst, in the step of separating unreacted monomers from the polymerization reaction product, glycols are added to the liquid phase in the separator, and the separated unreacted monomers are This polymerization method allows the monomer to be recycled and used without purification. [Prior Art] A method for continuous slurry polymerization of olefins using a so-called Ziegler-Natsuta catalyst that combines a transition metal compound and an organoaluminium compound is as follows.
widely known. The industrial production method of such polyolefin usually consists of the following steps. That is, the steps include a polymerization step, an unreacted monomer separation step, a decatalyst step, a fractional drying step, a granulation step, and a purification step for monomers, solvents, and the like. On the other hand, in addition to the above-mentioned slurry (solvent) polymerization, olefin polymerization methods include bulk polymerization using liquid α-olefin itself as a dispersion medium and gas phase polymerization using gaseous α-olefin itself as a medium. Both of these polymerization types include an unreacted monomer separation step corresponding to the above. Generally, the pressure inside the unreacted monomer separator is lower than that of the polymerization vessel, so that the monomer in the slurry extracted into the vessel is violently vaporized, resulting in polymer particles adhering to the inner wall surface of the separator. Especially α−
When producing an olefin copolymer, the above-mentioned amount of adhesion increases due to an increase in the production rate of amorphous polymer and a worsening of the particle shape of the polymer (note: amorphous formation) compared to the case of producing a homopolymer. There is a tendency to When polymerization progresses inside the adhered particles, a polymer with a significantly high molecular weight is produced, which may result in FE in molded products (films, sheets, etc.) that use products containing such polymers. This seriously impairs the quality of poly-α-olefin products, such as causing yarn breakage in products (fibers). By the way, in the above-mentioned continuous slurry polymerization method, a catalyst deactivator is not added in the process because unreacted monomers are recycled to the reactor of the process. Therefore, the catalyst in the polymerization mixture that has undergone the process retains its polymerization ability even in the separator of the process, and the polymerization of the monomers continues. In general, the hydrogen concentration in the separator and the temperature of the polymerization mixture are lower than the temperature in the reactor, so the molecular weight of the polymer produced in the separator is lower than that of the polymer produced in the reactor. It will be much higher. Therefore, when a product containing such a high molecular weight polymer is molded into a film or the like, it causes fish eyes (FE), which poses a serious quality problem. The need to solve this problem is increasing because the reaction rate in the above-mentioned steps has become faster due to the recent development and introduction of highly active catalysts. This problem is more serious in continuous olefin polymerization processes than in batch polymerization processes for the following reasons. In other words, in the latter case, the residence time distribution of the catalyst occurs within the reactor, so that if the catalyst discharged from the reactor with a short residence time remains for a long time in the above-mentioned process, it will generate extremely high molecular weight polymer particles. Generate. This high molecular weight polymer is not uniformly mixed with other polymers even during melt kneading accompanying granulation or molding of the product polymer, causing FE and the like to occur in the molded product. The above problems are more common in the production of copolymers such as propylene/ethylene, propylene/C ₄ or more olefins, or propylene/ethylene/C ₄ or more olefins, rather than in the production of α-olefin homopolymers. It is even more serious. The reason is as follows. That is, in the case of copolymer production, a. The production rate of amorphous polymer increases, and b. The particle shape of the polymer deteriorates, c. Due to reasons (a) and (b), polymer particles tend to adhere to the separator wall surface, and (d). As a result of
The rate of occurrence of FE increases as the adhered particles repeatedly adhere to and fall off the wall surface over a long period of time. As a means of solving the above problems, several methods have been proposed in which a polymerization inhibitor is added in the unreacted monomer separation step mentioned above to prevent post-polymerization (Note: polymerization in a step after the polymerization step) due to unreacted monomers. has been done. That is, in JP-A-54-50588, carbon monoxide is added to the polymerization mixture. However, when such a gaseous polymerization inhibitor is used, the inhibitor is mixed and entrained in the unreacted monomers that are separated and recovered in the above-mentioned process, so that the monomers are directly used in the above-mentioned process. It becomes impossible to circulate and reuse the monomer in the polymerization process, and the recovered monomer must be purified, which is not economical. JP-A-58-135806 proposes a method of adding a branched alcohol having 3 to 8 carbon atoms to a polymerization mixture. However, in this case, if the alcohols are mixed into the unreacted monomers that are recovered and reused in the above process, even if the amount of the alcohols is small, the amount of the amorphous polymer in the copolymerization process may be reduced. This is not preferable because it not only increases the production rate and causes loss of monomers, but also leads to unstable polymerization or deterioration in the quality of the product polymer. In the slurry polymerization method using an inert solvent, the aforementioned alcohols are mixed into the solvent, so in order to recover and reuse the solvent, an extremely precise alcohol separation step is required. is necessary. Also, in the above step, the temperature of the polymerization mixture was 60°C.
If the temperature exceeds 0.9°C, the alcohol-catalyst complex decomposes and generates corrosive gas, which severely limits the operating conditions of the separator. In addition, a method has also been proposed in which hydrogen is added in the above-mentioned process to prevent the formation of high molecular weight polymers. However, in this case, a large amount of hydrogen is required, and as a result, the hydrogen entrained into the monomer recovery system reduces the capacity of the recovery compressor.
It is impossible to recycle the entire amount of recovered monomer to the polymerization vessel due to molecular weight adjustment, and the amount of monomer loss due to hydrogen being discharged outside the monomer recovery system increases. In addition to the above-mentioned proposals, Japanese Patent Application Laid-open No. 58-145708,
No. 58-145709 is a product (polymer) in an unreacted monomer separator in solventless slurry polymerization (bulk polymerization) using propylene monomer itself as a dispersion medium.
They have proposed a method in which a carboxylic acid ester or alkylene glycol is newly added as a polymerization inhibitor when obtaining the powder in powder form. However, when operating the unreacted monomer separator as a solvent-free powder fluidization tank, if the amount of polymerization inhibitor added is extremely small as described above, the agent will be immediately gasified by the large amount of coexisting monomers. , which accompanies the recovered unreacted monomer in a considerable proportion and inhibits the polymerization reaction when the monomer is recycled. The monomer must therefore be purified separately. The present inventors have repeatedly studied the process of separating unreacted monomers in the α-olefin polymerization method, which involves the technical problems described above. As a result, they came up with a process that does not involve the above-mentioned problems, and invented a continuous slurry polymerization of α-olefin that allows the recovered monomer to be recycled without being purified. [Object of the Invention] As is clear from the above description, the present invention has the advantage that there is almost no progress of polymerization in the monomer separation process, and therefore there is almost no high molecular weight product that causes FE in the product, and there is no polymerization in the recovered monomer. The object of the present invention is to provide a continuous slurry polymerization method for α-olefins which is substantially free from contamination with impurities that would actually inhibit the recycling use of the monomer. [Operation] The present invention has the following main configuration (1) and embodiment configurations (2) to (4). (1) A solid catalyst component containing titanium chloride obtained by reducing titanium tetrachloride with an organoaluminum compound in the presence of ether, a catalyst containing an organoaluminum compound, an inert solvent, and an α-olefin are continuously introduced into a reactor. The slurry consisting of the used catalyst, inert solvent, unreacted monomer and α-olefin polymer is continuously extracted to an unreacted monomer separator and the α-olefin is polymerized in the vessel. In a continuous slurry polymerization method for α-olefin in which unreacted monomers are separated and recovered from the slurry and recycled to the polymerization step, a) glycol ether is transferred from an unreacted monomer separator to a heat exchanger and then from a reactor to an unreacted monomer separator. The reaction slurry is supplied into the circulating reaction slurry before the heat exchanger in the reaction slurry circulation conduit connected to the polymerization slurry conduit leading to the process, and is mixed with the polymerization slurry extracted from the reactor after being heated by the heat exchanger. b) The unreacted monomers separated in the vessel are recycled to the polymerization process without being purified; c) The glycol ether is supplied at a ratio such that the unreacted monomers remain in the separator. A continuous slurry polymerization method for α-olefin, characterized in that the molar ratio to the organoaluminum compound in the slurry is 0.001 to 1.0, and the molar ratio to titanium in the solid catalyst component is 0.05 to 1.0. (2) The method for continuous slurry polymerization of α-olefin according to item (1) above, wherein the α-olefin is propylene, propylene and ethylene, an α-olefin having 4 to 8 carbon atoms, or a mixture of two or more thereof. (3) The glycol ether according to the above item (1), wherein the glycol ether is one or more selected from monoalkylene glycol monoalkyl ether, monoalkylene glycol dialkyl ether, polyalkylene glycol monoalkyl ether, or polyalkylene glycol dialkyl ether. α-olefin continuous slurry polymerization method. The α-olefin continuous slurry polymerization method according to item (1) above, wherein hydrogen is used during the polymerization of α-olefin in (4). The α-olefin polymerization catalyst used in the present invention is a stereoisomeric polymerization catalyst formed by combining a solid catalyst component containing a titanium component, particularly a titanium halide, and an organoaluminum compound. Suitable examples of the titanium component include α, β, γ, or δ type titanium trichloride, or a titanium compound supported on a carrier such as magnesium chloride. The titanium component or titanium compound is obtained by treating the titanium trichloride complexing agent obtained by reducing titanium tetrachloride with an organoaluminum compound, and then activating the object by a known method. The effect is particularly great when using a so-called highly active catalyst, or a catalyst in which titanium tetrachloride is supported on a carrier such as a magnesium compound. As the organic aluminum compound, preferably used is a compound represented by the general formula AlRn Y _3-o . Here, n is an arbitrary number satisfying 0<n3, Y is a halogen atom, and R is a hydrocarbon group having 2 to 16 carbon atoms, preferably an alkyl group or an aryl group.
Specifically, diethyl aluminum monochloride, triethyl aluminum, dipropyl aluminum monochloride, tributyl aluminum,
Examples include diethylaluminum monoiodide. In addition to the above-mentioned combinations, the catalyst used in the present invention may further contain an electron donor as a third component. As the electron donor, for example, organic acid esters, ethers, amines, ketones, and aldehydes are preferably used. Olefins used in the present invention include ethylene, propylene, and n-carbon atoms having 4 to 8 carbon atoms.
-Butene-1,n-propene-1,n-hexene-1,n-octene-1,3-methylbutene-
Examples include 1,4-methylpentene-1 and 3-methylpentene-1. These olefins can be used alone or in combination of two or more. Among these, polymerization methods involving propylene alone or a combination of propylene and other α-olefins are preferred targets of the present invention. The olefin polymerization reaction according to the present invention is carried out by a continuous slurry (solvent) polymerization method using an inert solvent. Examples of the inert solvent include hexane, heptane,
Saturated aliphatic hydrocarbons such as octane, aromatic hydrocarbons such as benzene, toluene, and xylene, and alicyclic hydrocarbons such as cyclopentane and cyclohexane are preferably used. In the method of the present invention, hydrogen is used as a molecular weight regulator under the following conditions. That is, the hydrogen concentration in the gas phase gas in the reactor is maintained at 0.1 to 70 mol%, preferably 1.0 to 10 mol%, and the pressure in the reactor is maintained at 1 to 40 Kg/ ^cm2G , preferably 5 to 25 Kg/cm2. cm ² G and a temperature of 20 to 100°C, preferably 40 to 80°C. The polymerization reaction time according to the present invention is preferably 0.5 to 15 hours as an average residence time. The reaction mixture thus withdrawn from the reactor is transferred as a slurry consisting of a mixture of polymers, monomers, catalyst components, trace amounts of hydrogen, solvents, and other oligomers to an unreacted monomer separator where the next separation step is carried out. Sent. To explain with the following diagram (flow sheet of the present invention), the monomers in the slurry discharged into the vessel 8 through the conduit 1 from the reactor are removed from the slurry in the vessel. The unreacted monomers are separated and recovered in gaseous form from the upper part of the separator, and then repressurized to the compressor 10, usually through the unreacted monomer gas line 3, the heat exchanger 9, and the filter 11, and then the unreacted monomers Conduit 4 for liquid to reactor
It is circulated and supplied to a reactor (not shown) through the . The structure of the unreacted monomer separator 8 may be tubular or tank-like, and in order to evaporate the monomers almost completely, a heated and vaporized solvent is supplied or a heat exchanger (not shown) is attached. The required heat of evaporation is supplied to the monomer in the vessel. The above-mentioned requirement a) regarding the method of the present invention, namely,
The glycol ethers are preferably added to the slurry in the unreacted monomer separation region in the liquid phase portion of the separator 8. For this purpose, a part of the slurry in the vessel is extracted through a pipe 6, and glycol ether is supplied from a pipe 2 connected to the slurry in the pipe, mixed, and heated by a heat exchanger 9''.
It is combined with the slurry withdrawn from the reactor in line 1 via line 6'. As mentioned above, by adding and mixing glycol ether to the liquid phase part,
The catalyst contained in the slurry and the glycol ether are sufficiently contacted to form a complex having a very low vapor pressure. Therefore, it is possible to prevent glycol ether from evaporating into the aforementioned unreacted monomer recovery system (three pipe directions). In addition, by heating the liquid phase slurry in the unreacted monomer separator 8 and mixing it with the slurry extracted from the polymerization vessel, the polymerization ability of the catalyst in these slurries is suppressed, and the slurry extracted from the reaction slurry conduit 5 is and unreacted monomer gas conduit 3
The temperature of the monomer gas extracted from the tank can be prevented from decreasing. In addition, it is possible to prevent polymerization at low temperatures on the inner wall surface of the separator 8, improve the cleaning effect of the wall surface, and prevent abnormal polymerization and adhesion. Additionally, the complex formed as described above is present in the conduit 5
In the polymer purification step (not shown) in which the slurry extracted from It has the characteristic that there is no risk of migration or contamination into product polymers (refined and reused) or product polymers. The glycol ethers used are monoalkyl ethers and dialkyl ethers of ethylene glycol and propylene glycol, with the general formula
RO (C ₂ H ₄ O) _o R', RO (C ₃ H ₆ O) _o R', where R and R' are hydrogen or an alkyl group having 1 to 8 carbon atoms,
R may be the same as or different from R'. n is 1 to 8
is preferable; if n is too large, the amount of polymerization inhibition required increases, which is economically disadvantageous. These glycol ethers can be used alone or in combination. Examples of typical glycol ethers include ethylene glycol monomethyl ether,
Ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol dipropyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monoethyl Ether, propylene glycol diethyl ether, propylene glycol monopropyl ether, propylene glycol dipropyl ether, propylene glycol monobutyl ether, propylene glycol dipropyl ether, and condensates of ethylene glycol such as diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethyl Glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dihexyl ether, triethylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol diethyl ether, hexaethylene glycol dipropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether,
Examples include tripropylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, hexapropylene glycol dimethyl ether, and the like. The amount of glycol ether used is preferably 1.0 mol or less per 1 mol of catalyst organoaluminum and 0.05 mol or more per 1 mol of catalyst titanium component.
If the amount is more than 1 mole per mole of organic aluminum, glycol ether will be entrained in the unreacted monomer recovery system, inhibiting the polymerization reaction. Furthermore, if the amount is less than 0.05 mole per mole of titanium component, the effect of inhibiting polymerization in the separator will be small and FE prevention will be insufficient. [Effects] The effects of the present invention are summarized below: The occurrence of FE can be prevented. Unreacted monomers can be reused in polymerization without purification. This prevents polymer adhesion and growth on the wall of the unreacted monomer separator, allowing for long-term stable operation. There is no need to worry about equipment corrosion. Does not inhibit the purification effect of the polymer. Glycol ether can be easily removed by washing with water, and there is no problem of polymer contamination or solvent contamination. The effect of preventing FE is particularly large when producing propylene copolymers. etc. [Example] Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the Examples. Test method Γ Melt flow rate (MFR): ASTM
D1238 (g/10 min) Γ Haze: ASTM D1003 (%) Γ App production rate: Polymerization solvent-dissolved polymer / Powdered polymer + Polymerization solvent-dissolved polymer x 100 (%) Γ Catalyst efficiency (CY): Powdered polymer amount / titanium Component containing catalyst amount (g/
g) ΓFitshiyu Eye (FE): Chitso method (pcs/1000
cm ² ) Γ Polymer composition: determined by infrared spectrophotometer. Example 1 1) Production of catalyst 60 ml of n-hexane, 0.50 mol of diethylaluminium monochloride (DEAC), and 1.20 mol of diisoamyl ether were mixed at 25°C for 1 minute and reacted at the same temperature for 5 minutes to obtain the reaction product liquid (). (diisoamyl ether/DEAC molar ratio 2.4) was obtained. Put 4.0 mol of titanium tetrachloride into a reactor purged with nitrogen,
Heated to 35°C, added dropwise the entire amount of the above reaction product solution () over 180 minutes, kept at the same temperature for 30 minutes,
The temperature was raised to 5°C and the reaction was further carried out for 1 hour, cooled to room temperature, the supernatant liquid was removed, 4000 ml of n-hexane was added, and the supernatant liquid was removed by decantation, which was repeated 4 times to obtain a solid product ( ) Obtained 190g. With the entire amount of this () suspended in 3000 ml of n-hexane, 160 g of diisoamyl ether and 350 g of titanium tetrachloride were added at room temperature for about 1 minute at 20°C.
The reaction was carried out at ℃ for 1 hour. After the reaction is complete, leave room temperature (20
℃), remove the supernatant liquid by decantation, add 4000 ml of n-hexane, stir for 10 minutes, leave to stand, remove the supernatant liquid, repeat the operation 5 times, and reduce the pressure. Dry the solid product under ()
I got it. 2) Preparation of catalyst Charge 40 g of n-hexane, 850 g of diethylaluminium monochloride, 360 g of the above solid product, and 3.13 g of diethylene glycol dimethyl ether into a tank with an internal volume of 50, then add propylene gas at 180/H while stirring while maintaining the temperature at 30°C. supply for 4 hours,
Performed preliminary processing. 3) Polymerization method: 22% propylene per hour into a polymerization vessel with an internal volume of 150%,
n-hexane 15, the above catalyst mixed slurry 0.15
, 15N of hydrogen gas was continuously supplied, and polymerization was carried out at a reaction temperature of 70° C., a reaction pressure of 10 Kg/cm ² G, and a gas phase hydrogen concentration of 3 mol %. The liquid level in the polymerization vessel is 80
The volume of slurry is adjusted intermittently by the opening time of the control valve to maintain the same percentage.
100 unreacted monomer separation tank.
The separation tank was set at 60℃ and 0.2Kg/cm ² G, and the gasified and separated unreacted propylene was liquefied by a compressor, 80% was circulated to the polymerization vessel, and 20% was released outside the system. . The liquid phase slurry in the separation tank was constantly circulated by a pump through a heat exchanger and from downstream of the polymerization reactor withdrawal control valve through a slurry withdrawal line to the separation tank. 0.58 g of diethyl glycol dimethyl ether diluted with n-hexane was supplied per hour to the pump inlet of this circulation line using a metering pump. The reaction mixture slurry containing polymer particles was transferred to a purification tank, killed with methanol, neutralized with caustic soda water, washed with water, separated into individual liquids using a centrifuge, and dried at 90°C in a nitrogen gas atmosphere. Product polymer was obtained at approximately 8 Kg per hour. The main polymerization reaction was continued for 3 days and the quality of the polymer was evaluated. The soluble polymer dissolved in the solvent during polymerization was also distilled off and measured as the App production rate. After the polymerization was completed, the separator was opened and the state of polymer adhesion was observed. 4) Granulation method Product polypropylene powder 5.0Kg, phenolic heat stabilizer 0.005Kg, calcium stearate 0.005Kg
Kg and 0.015 Kg of silica powder with an average particle size of approximately 2μ was added using a high-speed stirring mixer (Hensiel mixer,
(trade name) for 3 minutes, and the mixture was granulated by extrusion with a screw D diameter of 40 mm. 5) Film forming method The granules were formed into a film with a thickness of 30 μm using a 40 mm T die (rip width 30 cm) manufactured by Yamaguchi Seisakusho Co., Ltd., and a film with a diameter of 0.1 μm was formed using a film tie counter manufactured by Yaskawa Electric Co., Ltd.
The number of foreign objects larger than mm was measured. The measurement area was 30,000 cm ² and converted to 1000 cm ² . Furthermore, polymeric
In order to distinguish between FE and foreign material FE, we observed the FE under a microscope while heating it with a micro-melting point apparatus manufactured by Yanagimoto Seisakusho Co., Ltd., and observed that the FE was melted at 165°C or less and optically separated from the surrounding film. Those that were uniform were considered polymers, and the others were considered foreign substances. FE
Observations were made 10 times each, and the ratio was calculated. The results are shown in Table-1. Comparative Example 1 The same procedure as in Example 1 was carried out except that the addition of diethylene glycol dimethyl ether to the separator was omitted. When glycol ether was not added, the generation of FE increased rapidly as the operating time progressed, and polymer adhesion and growth were observed inside the separator. Examples 2 and 3, Comparative Examples 2 and 3 Example 1 was carried out by changing the amount of diethylene glycol dimethyl ether added to the separator. When the amount added was small as in Comparative Example 2, the effect of preventing FE was insufficient. In addition, when the amount of organic aluminum is equal to or more than that in Comparative Example 3, the additive is entrained in the recycled monomer, which is undesirable because it reduces the polymerization activity of the catalyst. Examples 4, 5, 6, 7, 8, 9, 10, 11 Example 1 was carried out by changing the type of glycol ether as shown in the table. In each case, the same FE prevention effect as in Example 1 was shown. Comparative Example 4 In Example 1, isopropyl alcohol was used instead of glycol ether. in this case
If the amount added is sufficient to achieve the FE prevention effect,
Isopropyl alcohol from the recycled propylene system entered the polymerization system, reducing the polymerization activity of the catalyst and increasing the App production rate. Comparative Examples 5 and 6 Isoamyl alcohol and ethyl acetate were used in place of the glycol ether in Example 1, respectively. As in Comparative Example 4, the polymerization activity of the catalyst decreases and the App production rate increases, which is not preferable. Comparative Example 7 In Example 1, the circulation of the liquid phase slurry in the separator was omitted, and ethylene glycol dimethyl ether was added directly downstream of the slurry extraction valve from the polymerization vessel. As shown in the table, the recovered unreacted propylene was accompanied by ethylene glycol dimethyl ether, possibly due to insufficient contact with the organoaluminium, and the polymerization activity of the catalyst was reduced. Comparative Example 8 The same procedure as in Comparative Example 7 was carried out except that dimethylene glycol dimethyl ether was added to the liquid phase of the separator. In this case, the prevention effect of FE was significantly reduced, and polymer particles also adhered to the separator wall. Example 12 1) Preparation of catalyst 200 g of anhydrous magnesium chloride, 100 ml of ethyl benzoate and 60 ml of methylpolysiloxane were ground in a ball mill for 100 hours. 150 g of the obtained solid product was suspended in 2000 ml of titanium tetrachloride, stirred at 80°C for 2 hours, the liquid was removed by filtration, and further diluted with n-hexane until no titanium tetrachloride was detected in the filtrate. After washing and drying, a solid catalyst was obtained. 2) Preparation of catalyst As in Example 1, 40 g of n-hexane, 850 g of triethylaluminum, and p
250 g of methyl toluate and 180 g of the above-mentioned solid catalyst were charged, and then propylene gas was supplied at 90 g/H for 4 hours while maintaining the temperature at 30°C and stirring to carry out preliminary polymerization. 3) Polymerization method Triethylene glycol dimethyl ether
It was carried out in exactly the same manner as in Example 5 except that it was added at 0.378 g/H. The results are shown in Table-2. Comparative Example 9 The same procedure as in Example 12 was carried out except that triethylene glycol dimethyl ether was omitted. When glycol ether was not added, FE generation increased rapidly with the passage of polymerization time, and it was shown that polymer adhesion to the separator wall was also very large. Comparative Example 10 The same procedure as in Example 12 was carried out except that carbon monoxide was added instead of glycol ether. Carbon monoxide in the recovered unreacted propylene entered the polymerization vessel, and the polymerization was stopped. Example 13 22.5 propylene per hour under the polymerization conditions of Example 1.
/H, n-hexane 15/H, ethylene gas
250N/H, 1-butene 1.8/H, hydrogen 15N
/H, the catalyst mixed slurry was continuously supplied at 0.15/H, the reaction temperature was 60°C, the pressure was 10 Kg/cm ² G, and the hydrogen concentration in the gas phase was 3 mol%. Comparative Example 11 The same procedure as in Example 13 was carried out except that glycol ether was not added to the separator. The results are shown in Table 3. In the case of copolymers, there was more adhesion to the separator, growth, and occurrence of FE than when producing propylene homopolymers, but the above problems were completely solved by the addition of glycol ether. Comparative Example 12 (Standard conditions) Propylene 22/hour in a polymerization vessel with an internal volume of 150,
0.05% of the catalyst slurry of Example 1 and 50N of hydrogen were continuously supplied, the reaction temperature was 70°C, and the gas phase hydrogen concentration was 3.5.
Bulk polymerization was carried out in mol %. Remove the polymerization slurry so that the liquid level in the polymerization vessel is 80%,
The unreacted propylene was transferred to a separator. The unreacted monomer separator is controlled at a temperature of 70℃ and a pressure of 0.1Kg/cm ² G, and unreacted monomers are added with diethylene glycol dimethyl ether heated to 90℃ by a heater via a compressor and circulated in gaseous form to the separator. The internal temperature was maintained inside the separator. The separator was operated as a gas-phase fluidized tank with propylene passing through the lower gas distribution plate and the overflow yielded polypropylene powder at a rate of about 8 Kg/Hr. A portion of the propylene circulating through the separator was liquefied by a compressor and reused in the polymerization vessel.
As shown in Table 3, diethylene glycol dimethyl ether entered the polymerization reactor from the circulating monomer system, resulting in a decrease in CY (CY in Comparative Example 13).
13000 is the normal value). Comparative Example 13 The same procedure as in Comparative Example 12 was carried out except that the addition of diethyl glycol dimethyl ether was omitted.

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【table】 [Brief explanation of the drawing]

The figure is an explanatory diagram (flow sheet) of the unreacted monomer separation step according to the method of the present invention. In the figure: 1... Conduit from the reactor, 2... Glycol ester conduit, 3... Unreacted monomer gas conduit, 4... Conduit for unreacted monomer liquid to the reactor, 5
...Reaction slurry extraction conduit, 6. Reaction slurry circulation conduit, 7. Washing solvent conduit, 8. Unreacted monomer separator, 9. Heat exchanger, 10. Compressor,
11...filter, 12...pump.

Claims (1)

[Scope of Claims] 1. A solid catalyst component containing titanium chloride obtained by reducing titanium tetrachloride with an organoaluminum compound in the presence of ether, a catalyst containing a combination of an organoaluminum compound, an inert solvent, and an α-olefin in a reactor. The α-olefin is continuously fed into the vessel to polymerize the α-olefin in the vessel, and the unreacted monomer is continuously separated from the slurry consisting of the used catalyst, the inert solvent, unreacted monomers, and α-olefin polymer. In the continuous slurry polymerization method for α-olefin, in which unreacted monomers are separated and recovered from the slurry into a slurry and recycled to the polymerization step, a) glycol ether is removed from the unreacted monomer separator, passed through a heat exchanger, and then unreacted from the reactor. The polymerization slurry is supplied into the circulating reaction slurry before the heat exchanger in the reaction slurry circulation conduit connected to the polymerization slurry conduit leading to the reaction monomer separator, and is extracted from the reactor after being heated by the heat exchanger. (b) The unreacted monomers separated in the vessel are recycled to the polymerization process without being purified; (c) The supply ratio of the glycol ether is adjusted to the level within the unreacted monomer separator. α characterized in that the molar ratio is 0.001 to 1.0 with respect to the organoaluminum compound in the slurry retained in the solid catalyst component and 0.05 to 1.0 with respect to titanium in the solid catalyst component.
- Continuous slurry polymerization of olefins. 2. The continuous slurry polymerization method for α-olefin according to claim 1, wherein the α-olefin is propylene, propylene and ethylene, an α-olefin having 4 to 8 carbon atoms, or a mixture of two or more thereof. 3. Claim 1 in which the glycol ether is one or more selected from monoalkylene glycol monoalkyl ether, monoalkylene glycol polyalkyl ether, polyalkylene glycol monoalkyl ether, or polyalkylene glycol polyalkyl ether
α-olefin continuous slurry polymerization method described in Section 1. 4. The α-olefin continuous slurry polymerization method according to claim 1, wherein hydrogen is used during polymerization of α-olefin.