JPH0138122B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyolefin. More particularly, the present invention relates to a method for polymerizing olefins using a catalyst system consisting of solid titanium trichloride, an organoaluminium compound, and a specific combination of electron-donating compounds. Conventionally, when polymerizing olefins, especially stereospecific polymerization of α-olefins, using a catalyst system consisting of a solid titanium trichloride catalyst and an organoaluminum compound, it has not been possible to use an electron-donating compound as a third component. well known. In this case, the purpose of using an electron-donating compound as the third component of the catalyst system is to improve the stereoregularity of the resulting polymer even a little, thereby reducing the amount of by-product amorphous polymer. The purpose is to reduce the amount of crystalline polymer and improve the yield of crystalline polymer, or to improve the rigidity of molded articles obtained from the produced polymer, and one of them is to improve the bulk density and particle size distribution of the produced polymer powder. The purpose of this is to improve the properties of polymerized powders or slurries by improving their properties, such as to facilitate the handling and transport of polymerized powders or slurries, and to reduce the capacity of reactors. It is common knowledge that many studies have been conducted and considerable results have been obtained. For example, Tokuko Sho 44-21337 and Tokuko Sho 49-
In 4832, a third component is used in the polymerization of propylene using a catalyst system consisting of titanium trichloride obtained by reducing TiCl ₄ with Al, followed by pulverization and activation, and an organoaluminium compound such as diethylaluminum monochloride. A method has been proposed for improving the stereoregularity of polypropylene by using carboxylic acid derivatives such as methacrylic esters or acrylic esters, or vinyl ethers such as ethyl vinyl ether. Furthermore, in the 1970-12140 special public service, the third
A similar method has been proposed for improving the stereoregularity of polypropylene by using a benzoic acid derivative such as ethyl benzoate as a component.
When the oxygen-containing compounds listed here are used as the third component, they improve the stereoregularity of the resulting polymer, but at the same time the polymerization rate decreases little, and in these respects they are industrially useful third components. It can be said that it is one of the In addition, in Japanese Patent Publication No. 39-19546, propylene is polymerized in an aliphatic or alicyclic saturated hydrocarbon solvent substantially free of oxygen compounds using a catalyst system consisting of titanium trichloride and an organoaluminum compound. In this regard, a method has been proposed in which the stereoregularity and bulk density of polymerized powder are improved by using an aromatic hydrocarbon such as toluene as a third component or part of the polymerization solvent, and the present inventors have proposed Part of this was previously reported in Japanese Patent Publication No. 55-9001 by polymerizing propylene using a catalyst system consisting of a highly active titanium trichloride-based catalyst complex produced by a specific method, an organoaluminum compound, and an aromatic hydrocarbon. sex,
We proposed a method to obtain polypropylene with high bulk density and high catalytic efficiency. On the other hand, in the case of packaging films, which are one of the major uses of polypropylene, transparency and impact resistance are major factors that determine commercial value, and it is preferable that both transparency and impact resistance are higher. However, according to studies conducted by the present inventors, when propylene is polymerized using a conventionally known electron-donating compound as the third component of the catalyst system, polypropylene with high stereoregularity and bulk density of the polymer powder is obtained. However, it has been found that when it is extruded into a water-cooled blown film or a T-die film, its transparency and impact resistance are reduced. Moreover, as the stereoregularity of the resulting polymer is improved, such as by increasing the amount of the third component, the so-called "stiffness" of the film will be improved, but on the other hand, the transparency and impact resistance mentioned above will be improved. The decline in The reason for this is of course not clear, but according to the studies of the present inventors, one of the factors that has a close correlation with the transparency and impact resistance of the film is the molecular weight distribution of the polymer, and this molecular weight distribution Furthermore, it was found that there is a close correlation with the type and amount of the third component during polymerization. That is, when conventionally known electron-donating compounds are used, the stereoregularity of the polymer is of course improved, but at the same time, the molecular weight distribution also increases, and the transparency and impact resistance of the film tend to decrease. It was done. Although it is currently unclear why there is a correlation between these two properties of the film and the molecular weight distribution, the present inventors have conducted extensive studies to solve this drawback by preventing an increase in the molecular weight distribution. As a result, when certain combinations of electron-donating compounds are used as the third component, the stereoregularity is improved, but the molecular weight distribution remains small, resulting in improved film transparency and impact strength. This is a totally surprising result that could not have been predicted from the prior art. According to the method of the present invention, a polymer with sufficiently large stereoregularity and large bulk density can be obtained by combining the catalyst and cocatalyst with high activity, that is, with high catalytic efficiency. This method is also advantageous from the viewpoint of the manufacturing process, as it makes it possible to omit the step of removing residual catalyst and to streamline the step of removing residual catalyst. Therefore, the gist of the present invention is to precipitate titanium tetrachloride from a liquid containing liquefied titanium trichloride in the presence of an ether or thioether at a temperature of 150°C or lower, or to precipitate titanium tetrachloride from an organoaluminum compound or metal aluminum. Solid titanium trichloride obtained by treating solid titanium trichloride obtained by reduction with a complexing agent and a halogen compound, an organoaluminum compound, an aromatic hydrocarbon, and an aromatic polycyclic condensed ring in the molecule. The present invention relates to a method for producing a polyolefin, which comprises polymerizing an α-olefin using a catalyst system comprising a monocarboxylic acid ester having the following properties. To explain the present invention in detail, solid titanium trichloride used as a catalyst includes pure titanium trichloride obtained by hydrogen reduction of titanium tetrachloride, and titanium trichloride obtained by aluminum reduction of titanium tetrachloride. Aluminum chloride eutectic (TiCl ₃ ^- 1/3AlCl ₃ ) and mechanically crushed products of titanium trichloride can also be used, but the amount of amorphous polymer that must be removed is small, simplifying the catalyst removal process. It is preferable to use the following solid titanium trichloride-based catalyst complex, which is a highly active catalyst, because it can be omitted or the powder properties of the resulting polymer are good. Such solid titanium trichloride catalyst complexes are disclosed in Japanese Patent Application Laid-open No. 47-34478, No. 48-64170, No. 50-
112289, 50-143790, 51-16297, 51-
16298, 51-76196, 51-123796, etc., but to explain, the aluminum content is 0.15 or less in the atomic ratio of aluminum to titanium, preferably 0.1 or less, more preferably 0.02 or less, and complex. It contains a curing agent. The content of the complexing agent is the molar ratio of the complexing agent to titanium trichloride in the solid titanium trichloride-based catalyst complex.
It is 0.001 or more, preferably 0.01 or more. Specifically, titanium trichloride, the formula AlR ¹ _p where the atomic ratio of aluminum to titanium in titanium trichloride is 0.15 or less
X _3-p (wherein, R ¹ is a hydrocarbon group having 1 to 20 carbon atoms,
is a halogen atom, p is the number of 0≦p≦2), and contains a complexing agent in a molar ratio of 0.001 or more to aluminum halide and titanium trichloride, for example, compounds with the formula TiCl ₃ (AlR ¹ _p X _3-p ) _s・(C) _t (wherein, R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, and
is a halogen atom, p is a number of 0≦p≦2, C is a complexing agent, s is a number of 0.15 or less, and t is a number of 0.001 or more). Of course, _{the three} components of TiCl,
In addition to _{the AlR} ¹ _p It may also contain inorganic solids, olefin polymer powders such as polyethylene, polypropylene, etc. Examples of the complexing agent C include ethers, thioethers, ketones, carboxylic acid esters, amines, carboxylic acid amides, and polysiloxanes, among which ethers and thioethers are particularly preferred. As the ether or thioether, the general formula R ² -O-R ³ or
Examples include those represented by ^R2 -S- ^R3 (wherein ^R2 and ^R3 represent a hydrocarbon group having 15 or less carbon atoms). Examples of AlR ¹ _p X _3-p include AlCl ₃ and AlR ¹ Cl ₂ . Further, it is particularly preferable that the solid titanium trichloride-based catalyst complex has an X-ray diffraction pattern having a halo of maximum intensity at a position corresponding to the strongest peak position of α-type titanium trichloride (near 2θ=32.9°). Furthermore, during the production of solid titanium trichloride-based catalyst complexes,
Those that have not been subjected to thermal history at temperatures exceeding 150°C are preferred. Furthermore, the cumulative pore volume with a pore radius between 20 Å and 500 Å measured using the mercury porosimeter method is
Those characterized by a pore volume with an extremely fine pore diameter of 0.02 cm ³ /g or more, especially 0.03 cm ³ /g to ^{0.15 cm 3} /g, are advantageous in that there is no need to remove the amorphous polymer. , particularly preferred. However, such a solid titanium trichloride-based catalyst complex can be prepared from a liquid containing titanium trichloride liquefied in the presence of (a) ether or thioether at 150°C;
Precipitate at the following temperatures (b) Solid titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound or metal aluminum is treated with a complexing agent and a halogen compound (a) or (b) Manufactured by a method. The following two methods can be used to obtain a liquid material containing liquefied titanium trichloride in method (a). (A) A method in which titanium tetrachloride is used as a starting material and reduced with an organoaluminum compound in the presence of an ether or thioether and, if necessary, a suitable hydrocarbon solvent. (B) Using solid titanium trichloride as a starting material, if necessary in the presence of a suitable hydrocarbon solvent,
Method of treatment with ether or thioether. There are no particular restrictions on the method for precipitating the fine particulate solid titanium trichloride catalyst complex, and the liquid may be deposited as it is or after adding a hydrocarbon diluent if necessary, at a temperature of 150°C or lower, preferably 40 to 120°C. , Particularly preferably, the temperature is raised to 60 to 100°C to precipitate. Note that when the total number of moles of titanium and aluminum in the titanium trichloride liquid is smaller than the number of moles of ether or thioether, a liberating agent may be added to promote precipitation. As liberating agents, titanium tetrachloride, aluminum halide,
For example, aluminum trihalide, alkyl aluminum dihalide, and the like are preferred. The amount of the liberating agent used is preferably 5 moles or less of titanium in the liquid. As the complexing agent in the method (b), those exemplified above as complexing agent C can be similarly mentioned.
Examples of the halogen compound include titanium tetrachloride and carbon tetrachloride. The complexing agent treatment and the halogen compound treatment may be performed simultaneously, or the complexing agent treatment may be performed first and then the halogen compound treatment may be performed. The complexing agent treatment is usually carried out by adding a complexing agent to solid titanium trichloride in a diluent in an amount of 0.2 to 3 moles relative to TiCl ₃ at a temperature of -20 to 80°C. After the complexing agent treatment, it is preferable to separate and wash the obtained solid. Halogen compound treatment is usually carried out in a diluent at a temperature of -10 to 50°C. The amount of halogen compound used is usually 0.1 per TiCl ₃
~10 times by mole, preferably 1 to 5 times by mole. After the halogen compound treatment, it is preferable to separate and wash the obtained solid. On the other hand, the organoaluminum compound of the cocatalyst has the general formula AlR ⁴ _o Cl _3-o (wherein R ⁴ has a carbon number of 1 to 20
is a hydrocarbon group, n is a number from 1.95 to 2.10). Among them, diethylaluminum monochloride in which R ⁴ is an ethyl group and n is 2 can be used satisfactorily;
Particularly preferred are the cocatalysts described in No. 55-38833, in which R ⁴ is normal propyl group or normal hexyl group. When R ⁴ is normal propyl group or normal hexyl group, n is 1.95≦n≦
It is important that the ratio is 2.10, and within this range, high results can be obtained in both polymerization activity and stereoregularity by polymerizing in combination with the solid titanium trichloride catalyst complex described above. Among the two kinds of third components used, aromatic hydrocarbons are hydrocarbons having a single ring or polycycles, and hydrocarbon groups such as alkyl groups and alkenyl groups,
Alternatively, it may have a substituent such as a halogen. Specifically, benzene, toluene, ethylbenzene, xylene, styrene, n-propylbenzene, ethyltoluene, trimethylbenzene,
Monocyclic aromatic hydrocarbons such as tetramethylbenzene and chlorobenzene; polycyclic aromatic hydrocarbons such as diphenyl, diphenylmethane, triphenylmethane, naphthalene, methylnaphthalene, dimethylnaphthalene, vinylnaphthalene, phenanthrene, anthracene, vinylanthracene, etc. However, when using the solid titanium trichloride-based catalyst complex, it is advantageous to use the same type of solvent as the one used in its production or prepolymerization from the viewpoint of solvent recovery, as well as being inexpensive and easy to handle. Monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene, which are liquid at room temperature and have a relatively low boiling point, can also be used as the above-mentioned solvents because they are easy to hydrate and easily volatilize when drying the polymer. preferable. Monocarboxylic acid esters having aromatic polycyclic condensed rings in the molecule (hereinafter simply referred to as monocarboxylic acid esters) include monocarboxylic acid esters having naphthalene, anthracene, pyrene, indene, fluorene, etc. . Preferably methyl, ethyl α-naphthoic acid,
Butyl, amyl, octyl ester; Methyl, ethyl, butyl, amyl, octyl ester of β-naphthoic acid; Methyl, ethyl, butyl, amyl, octyl ester of anthracene-1-carboxylic acid; Methyl of anthracene-2-carboxylic acid, Ethyl, butyl, amyl, octyl ester; methyl, ethyl, butyl, amyl, octyl ester of anthracene-9-carboxylic acid and the like. Furthermore, those in which the hydrogen atom of the above-mentioned aromatic ring is substituted with an alkyl group can also be used. The ratio of each catalyst component used is usually a molar ratio of titanium trichloride: organoaluminum compound: aromatic hydrocarbon: monocarboxylic acid ester in solid titanium trichloride: 1:1 to 100:1 to 10000:0.01 to 10. , preferably from 1:2 to 40:5 to 5000:0.05 to 2. When polymerization is carried out in a hydrocarbon solvent, the aromatic hydrocarbon is used in an amount of 0.01 to 20% by volume, preferably 0.1 to 10% by volume, based on the solvent. If this amount is too small, the effect of improving the transparency and impact resistance of the film will not be sufficient, and if it is too large, the burden of recovering aromatic hydrocarbons from the polymer or polymerization solvent will increase, which is undesirable. The impact appears. In the method of the present invention, a catalyst system is prepared from the solid titanium trichloride, an organoaluminum compound, and a third component consisting of an aromatic hydrocarbon and a monocarboxylic acid ester. can also be adopted. For example, a method of simply mixing the above four components in advance in a hydrocarbon solvent such as hexane, heptane, benzene, or toluene (if aromatic hydrocarbons such as benzene or toluene are used as a solvent, the total number of moles of them is (selected so that the ratio used), the above-mentioned two components, for example, an organoaluminum compound and a monocarboxylic acid ester, may be mixed in advance. Although there are no particular restrictions on the mixing temperature, time, etc., the temperature is usually room temperature to the polymerization temperature, and the time is preferably not too long, usually within several days. Alternatively, a method may be adopted in which each of the catalyst components is separately supplied to the polymerization vessel without being mixed in advance. Further, the solid titanium trichloride used as a catalyst may be used as it is in the polymerization, but it is preferably used after being pretreated with a small amount of the olefin in the presence of an organoaluminum compound. This pretreatment is effective in improving the physical properties of the polymer slurry, such as bulk density. Pretreatment is performed at a temperature lower than the polymerization temperature, generally from 20℃
The treatment is carried out at 60° C. so that the polymer produced by the pretreatment/titanium trichloride in the solid titanium trichloride ratio is 0.1 to 50/1 (weight ratio), usually 1 to 20/1. As the solvent for this pretreatment, aliphatic hydrocarbons such as hexane and heptane, and alicyclic hydrocarbons such as cyclohexane can be used, but aromatic hydrocarbons themselves, which are added as the third component such as benzene and toluene, can be used as solvents. It is preferable to use it because it improves not only the stereoregularity but also the bulk density of the final polymer. Therefore, in the present invention, α-olefin is polymerized in the presence of a catalyst system consisting of solid titanium trichloride, an organoaluminum compound, and a third catalyst component. As α-olefin, propylene, butene-1,3-methylbutene-1,4
Examples include methylpentene-1, pentene-1, hexene-1, etc., and homopolymerization of these α-olefins, mixtures of these with ethylene, random copolymerization of mixtures of these with each other, or α- Block copolymerization of olefins or of these α-olefins and ethylene is carried out. It is particularly suitable for stereoregular polymerization to produce a propylene homopolymer, a random copolymer containing 90% by weight or more of propylene, or a block copolymer containing 80% by weight or more of propylene. The polymerization reaction may be carried out by gas phase polymerization or by slurry polymerization in the presence of a solvent.
Examples of the solvent include aliphatic hydrocarbons such as pentane, heptane, hexane, and decane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; however, the above-mentioned olefins themselves such as propylene are also preferably used. In addition, the polymerization reaction can be carried out either batchwise or continuously, and there are no particular limitations on the polymerization temperature and pressure, but usually,
The temperature is 50 to 100°C, preferably 60 to 90°C, and the pressure is about atmospheric pressure to 100 atm. In addition, during polymerization, the molecular weight of the produced polymer can be controlled using a known molecular weight controlling agent such as hydrogen or halogenated hydrocarbon. Olefin polymerization is carried out as described above, and the effects of high polymerization activity and high stereoregularity brought about by the method of the present invention are due to the high catalytic efficiency of polymerization, such as titanium trichloride (TiCl ₃ ) in solid titanium trichloride. This is particularly noticeable in polymerizations in which 5,000 grams or more, preferably 10,000 grams or more of polymer is produced per gram, and the amount of catalyst remaining in the polymer is further reduced, and the stereoregularity of the resulting polymer is improved. Such high catalytic efficiency polymerizations are particularly preferred because they improve the efficiency of polymerization. According to the method for producing polyolefin of the present invention described in detail above, not only high results are obtained in both polymerization activity and stereoregularity of the polymer, but also high transparency and impact resistance are obtained when formed into a film. Results are obtained and excellent effects not seen with conventional methods are achieved. Therefore, the present invention has great industrial value. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, in the examples and comparative examples, the catalyst efficiency CE is the total amount of propylene polymer produced per 1 g of titanium trichloride in solid titanium trichloride,
Polymerization activity K per hour, propylene pressure 1Kg/cm ²
This is the total amount of propylene polymer produced per gram of titanium trichloride. The total amount of propylene polymer produced herein refers to the amount including the amorphous polymer. The bulk density ρ _B of the polymer powder was measured according to JIS-K-6721. II-XLN is the total amount of polymer remaining after completely dissolving the polymer together with a stabilizer in boiling xylene, leaving it to slowly cool to room temperature, filtering out the precipitated polymer, and washing with xylene. It represents the stereoregularity of the total polymer. Polymer melt flow index, MFI is
Measured according to ASTM-D1238. FR is 5.528Kg
Load, extrusion amount of molten polymer at 230℃,
This is a simple method to express the spread of molecular weight distribution by expressing it as the ratio of the same extrusion amount at 230°C under a load of 0.553 kg. Film haze (transparency) is determined by ASTM.
It was measured using a Nippon Denshoku haze meter according to D1003. This indicates the transparency of the film. In addition, the dirt, drop, impact, and DDI of the film are manufactured by Toyo Seiki in accordance with ASTM-D1709.
Measurements were made using a DDI measuring machine with a hemisphere of 1.5 inches and a height of 20 inches. This indicates the impact resistance of the film. Furthermore, FIGS. 1 and 2 are flowcharts to help understand the technical content included in the present invention, and the present invention is not subject to any restrictions by the flowcharts unless it deviates from the gist thereof. It's not a thing. Catalyst production example 1 (A) Production of solid titanium trichloride-based catalyst complex A 10 capacity autoclave that was sufficiently purged with nitrogen was charged with 5.0 g of purified n-hexane, and while stirring, 2.7 mol of di-n-octyl ether and tetrachloride were added. Titanium
3.0 mol was charged. The internal temperature was adjusted to 30°C, and 0.5% of an n-hexane solution containing 1.0 mol of diethylaluminum monochloride was added to obtain a brown homogeneous solution. When the temperature was then raised, purple fine particles of solid were observed to precipitate from around 50°C. After holding at 95°C for about 1 hour, granular purple solids were separated and washed repeatedly with n-hexane to obtain 345g of titanium trichloride solid catalyst complex. As a result of elemental analysis and gas-chromatography analysis, the composition of this substance is TiCl ₃・(AlCl ₃ ) _0.004・[(n-C ₈ H ₁₇ ) ₂ O]
It was _0.11 . (B) Pretreatment with propylene 12.5 mol of purified n-hexane was charged into an autoclave with a capacity of 20 that was sufficiently purged with nitrogen, and while stirring, 1.6 mol of diethylaluminium monochloride was added to the solid titanium trichloride catalyst obtained in (A) above. complex,
TiCl ₃ was charged in an amount of 250 g. Next, the internal temperature was adjusted to 30℃, and while stirring, propylene gas was started to be blown into the tank, resulting in 1250g of polymerized propylene.
Blowing of propylene gas was continued at the same temperature until the temperature reached . The solid was then separated and washed repeatedly with n-hexane to obtain polypropylene-containing titanium trichloride. Examples 1 to 4 and Comparative Examples 1 to 5 In a reactor with a capacity of 1.7 m ³ that was sufficiently purged with nitrogen,
By continuously supplying liquefied propylene and hydrogen at ℃, polypropylene-containing solid titanium trichloride (TiCl ₃ ) obtained in Catalyst Production Example 1 (B), di-n-propylaluminium monochloride (DPA), and aromatic carbonization were produced. Hydrogen and various monocarboxylic acid esters were continuously fed in the amounts shown in Table 1. The DPA/TiCl ₃ molar ratio was 8. Polymerization of propylene was carried out continuously at 70° C. with an average residence time of 5.0 hours at a propylene partial pressure of 31 Kg/cm ² and a molar ratio of hydrogen to propylene in the gas phase of 0.06 to 0.065. Table 1 shows the polymerization activity determined from the catalyst supply rate and polymer production rate. After purging unreacted propylene from the liquefied propylene slurry of the polymer, the polymer powder was heated with propylene oxide gas at 120 °C.
The treatment was carried out continuously at ℃. To the product powder obtained as above, 0.2% by weight of BHT and 0.3% by weight of silica were added as antioxidants and pelletized at 250℃ using a pelletizer with an inner diameter of 40mm, and then formed into a water-cooled inflation film with a thickness of 30μ. Molded. The haze (transparency) and DDI (impact resistance) of this film were measured. On the other hand, the FR of the pellets was measured. These results are summarized in Table 1. In Examples 1 to 3, polymerization was carried out using toluene as the aromatic hydrocarbon and various monocarboxylic acid esters. Comparative Examples 1 to 3 are conventionally known methods that do not use aromatic hydrocarbons, such as adding only monocarboxylic acid ester to reduce the production rate of amorphous polymer, or adding stereoregular II-XLN.
Increasing the film haze increases, that is, the transparency deteriorates, and the impact strength and DDI decrease. However, when toluene is used in combination as in Examples 1 to 3, the film haze decreases, that is, the transparency deteriorates. It is clear that the impact strength and impact strength DDI are improved. Furthermore, it can be seen that FR, which is an index of molecular weight distribution, also decreased. On the other hand, Comparative Example 4
In Comparative Example 5, only an aromatic hydrocarbon was used, and the transparency and impact resistance of the film were satisfactory. It shows a high production rate and low stereoregularity II-XLN. As a result, the rigidity of the film decreased. Another effect obtained by the method of the present invention is that when attempting to increase II-XLN using only a monocarboxylic acid ester, the decrease in polymerization activity K is relatively large, but when toluene is used in combination, the decrease in K is small. is clear from the comparison between Examples 1 to 3 and Comparative Examples 1 to 3. Example 4 is an example in which benzene was used as the aromatic hydrocarbon, but as in Examples 1 to 3, the amorphous polymer production rate decreased and the stereoregularity II-XLN improved, but the film It shows that both transparency and impact resistance are improved.

【table】

[Table] Catalyst production example 2 (A) Production of solid titanium trichloride-based catalyst complex 5.0 g of purified toluene was charged into an autoclave with a capacity of 10 that was sufficiently purged with nitrogen, and under stirring,
- 5.0 moles of butyl ether and 5.0 moles of titanium tetrachloride were charged. After adjusting the internal temperature to 30° C., 0.7 mol of a toluene solution containing 2.5 mol of diethylaluminum monochloride was added to obtain a brown homogeneous solution. Then, when the temperature was raised, fine particles of purple solid were precipitated from around 40°C. After being maintained at 95° C. for about 1 hour, granular purple solids were separated and washed repeatedly with toluene to obtain 778 g of titanium trichloride solid catalyst complex. As a result of elemental analysis and gas-chromatography analysis, the composition of this substance is TiCl ₃・(AlCl ₃ ) _0.003・[(n-C ₄ H ₉ ) ₂ O] _0
.
It was ₀₇ . (B) Pretreatment with propylene 12.5 mol of purified toluene was charged into an autoclave with a capacity of 20 that was sufficiently purged with nitrogen, and while stirring, 1.6 mol of di-propyl aluminum monochloride was added to the solid titanium trichloride catalyst obtained in (A) above. complex,
TiCl ₃ was charged in an amount of 250 g. Then, the internal temperature was adjusted to 20℃, and while stirring, blowing propylene gas was started, and 1250g of polymerized propylene was produced.
Blowing of propylene gas was continued at the same temperature until the temperature reached . The solid was then separated and washed repeatedly with toluene to obtain polypropylene-containing titanium trichloride. In Comparative Examples 6 to 9, which will be described later, after washing with toluene, toluene was replaced with n-hexane. Examples 5 to 8 and Comparative Examples 6 to 10 In Example 1, polypropylene-containing solid titanium trichloride obtained in Catalyst Production Example 2 (B) was used as the solid catalyst component, and aromatic hydrocarbons and monocarboxylic acid esters were Polymerization was carried out in the same manner as in Example 1, except that the type and amount of TiCl 3 used were as shown in Table 2, and the supply rate of TiCl ₃ was as shown in Table 2. Then, a water-cooled inflation film was formed and various measurements were carried out. I went. These results are summarized in Table 2. In Examples 5 to 7, various monocarboxylic acid esters were used in combination with toluene, which is a solvent for a solid titanium trichloride slurry containing polypropylene, and in Example 8, xylene was further added for polymerization. When compared with Comparative Examples 6 to 8, by using an aromatic hydrocarbon in combination with a monocarboxylic acid ester, the amorphous polymer production rate also decreased, and the stereoregularity II-
It is clear that as the XLN increases, the transparency and impact resistance of the film are improved. Similarly, the decrease in polymerization activity is small. Such an effect cannot be obtained by using either the monocarboxylic acid ester or the aromatic hydrocarbon alone, but can only be achieved by the combination of the two.

【table】

【table】 [Brief explanation of drawings]

1 and 2 are flowcharts showing one embodiment of the present invention.

Claims (1)

[Claims] 1. Precipitation at a temperature of 150°C or lower from a liquid containing titanium trichloride liquefied in the presence of an ether or thioether, or reducing titanium tetrachloride with an organoaluminum compound or metallic aluminum. solid titanium trichloride obtained by treating the obtained solid titanium trichloride with a complexing agent and a halogen compound, an organoaluminum compound, an aromatic hydrocarbon, and a monomer having an aromatic polycyclic fused ring in the molecule. Method 2 for producing polyolefin, characterized by polymerizing α-olefin using a catalyst system consisting of a carboxylic acid ester Solid titanium trichloride has an aluminum content of 0.15 as an atomic ratio of aluminum to titanium.
The manufacturing method according to claim 1, which uses a solid titanium trichloride catalyst complex which is as follows and contains a complexing agent.