JPH055842B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a propylene polymer. More specifically, the present invention relates to a method for producing a propylene polymer using solid titanium trichloride, which is suitable as a propylene polymerization catalyst. Conventionally, obtaining a polymer with high bulk density in the polymerization of propylene has been strongly desired in the technical field because it is possible to increase the slurry concentration in the reactor and therefore increase production capacity. There is. In addition, increasing the yield of crystalline polymer, that is, improving the stereoregularity of the polymer, increases the basic unit of raw material propylene and reduces the amount of amorphous polymer dissolved in the diluent. It becomes possible to simplify processing steps such as crystalline polymer removal, which is extremely advantageous industrially. In recent years, various methods have been proposed for polymerizing propylene with high catalytic efficiency using highly active catalysts. However, with these methods, it is difficult to obtain polymers with satisfactory bulk density and crystallinity in good yield, and therefore, improving this problem is of extremely important industrial significance. be. In line with this demand, a method has been proposed in which a catalyst system containing titanium trichloride and an organoaluminum compound is pretreated at a temperature lower than 60°C in the presence of propylene as a method to increase the bulk density and stereoregularity of the resulting polymer. (Refer to Japanese Patent Publication No. 49-14865). In this method, in the main polymerization after pretreatment, the bulk density and stereoregularity of the resulting polymer, which rapidly decrease as the polymerization temperature rises, are relatively gradually reduced in order to obtain high catalyst efficiency. However, it was difficult to say that a satisfactory effect could be obtained. In particular, the improvement effect was weak at a polymerization temperature of 60 to 70°C, which is realistic from an industrial point of view. In addition, in this method, it is essential that an appropriate amount of hydrogen be present in order to prevent the formation of molded articles from the produced polymer. However, controlling the appropriate amount of hydrogen is often difficult in practice. In other words, if the hydrogen content is too low, the molded product's hardness will increase.
If the amount is too large, the yield of the crystalline polymer will decrease, and even if a predetermined amount of hydrogen and propylene are charged, the hydrogen concentration will change due to propylene absorption. Also, β containing TiCl ₃ 1/3 AlCl ₃ or AlCl ₃
Activation of a propylene polymerization catalyst that slowly absorbs propylene into an inert solvent dispersion obtained from a δ-type titanium trichloride composition obtained by treating titanium trichloride with a complexing agent and pulverizing it, and an alkyl aluminum chloride. A law has been proposed (Japanese Unexamined Patent Publication No. 1973-
(See Publication No. 108693). However, with this method, it is not possible to increase the supply rate of propylene, and therefore an extremely long time is required for propylene absorption treatment. Furthermore, the yield of crystalline polymer cannot be said to be sufficiently high. Several proposals have been made to solve the above problems. For example, Special Publication No. 56-22816 and Special Publication No. 56-22816
No. 22817 is a method of pretreatment with propylene in the absence of hydrogen, and JP-A-53-10398 is a method of pretreatment with propylene in the presence of an electron donating substance. All of them have the industrial advantage that a high crystalline polymer yield can be obtained with high catalytic efficiency, and that the treatment can be performed even at relatively high temperatures. In addition, the molded products obtained by these methods include
It has the advantage that there are very few fisheyes. However, in recent years, there have been increasing expectations for further improvement in the yield of raw material propylene from the perspective of process economics, and even if the yield of crystalline polymer is 99%, for example, it cannot be said to be sufficient. It is. Furthermore, from the standpoint of quality, even higher rigidity is now required in some product application fields. Examples are the ultra-thin molding field and the food container field. The former has high rigidity and can be made thinner, and the latter is also required to have higher rigidity than ever before from the viewpoint of preventing food coloring.
It is also extremely important to maintain high catalytic efficiency, as in modern rational plants the step of removing the catalyst remaining in the polymer is either completely omitted or simplified. . In order to meet the above requirements, the inventors of the present invention have conducted intensive research and found that a specific solid titanium trichloride-based catalyst complex is treated in a specific manner in the presence of a specific unsaturated carboxylic acid ester. It was discovered that high catalytic efficiency and an extremely high yield of crystalline polymer can be obtained by polymerizing propylene using a catalyst system comprising the resulting propylene polymer-containing solid titanium trichloride and an organoaluminum compound. The invention has been achieved. That is, the gist of the present invention is as follows: (a) A liquid containing titanium trichloride liquefied in the presence of an ether or a thioether is heated to 150°C.
Obtained by precipitating at the following temperatures, or (b) by treating solid titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound or metal aluminum, and treating it with a complexing agent and a halogen compound. Aluminum content is the atomic ratio of aluminum to titanium
0.15 or less and containing a complexing agent, a solid titanium trichloride catalyst complex containing an inert solvent, an organoaluminum compound and a general formula (In the formula, R ¹ and R ² represent hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ³ represents an alkyl group having 1 to 20 carbon atoms.) Contact with propylene in the presence of a compound represented by 0.1 per gram of solid titanium trichloride on the complex.
propylene alone or containing small amounts of other α-olefins using a catalyst system comprising a propylene polymer-containing solid titanium trichloride obtained by producing ~100 g of propylene polymer and an organoaluminium compound. The present invention relates to a method for producing a propylene polymer, which comprises polymerizing propylene. The present invention will be explained in detail below. The solid titanium trichloride-based catalyst complex used in the present invention is (a) prepared from a liquid containing titanium trichloride liquefied in the presence of an ether or thioether at 150°C.
Obtained by precipitating at the following temperatures, or (b) by treating solid titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound or metal aluminum, and treating it with a complexing agent and a halogen compound. Aluminum content is the atomic ratio of aluminum to titanium
It is 0.15 or less, preferably 0.1 or less, more preferably 0.02 or less, and contains a complexing agent. The content of the complexing agent is preferably 0.001 or more in molar ratio of the complexing agent to titanium trichloride in the solid titanium trichloride-based catalyst complex.
It is 0.01 or more. Specifically, titanium trichloride,
The atomic ratio of aluminum to titanium in titanium trichloride is 0.15 or less and the formula AlR'pX ₃ -p (where
R' is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, and p is a number of 0≦p≦2). containing agents, such as those with the formula TiCl ₃ .AlR′pX ₃ -p) _s・(C) _t
(In the formula, R' is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, and p is 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), but of course,
In addition to the TiCl ₃ component, the AlR′pX ₃ -p component, and the complexing agent C component, a small amount of iodine, titanium trichloride in which part or all of the chlorine has been replaced with iodine or bromine, or MgCl ₃ , MgO It may contain inorganic solids for carriers such as olefin polymer powders such as polyethylene and polypropylene. Examples of the complexing agent C include ethers, thioethers, ketones, carboxylic acid esters, amines, carboxamides, and polysiloxanes, among which ethers and thioethers are particularly preferred. As an ether or thioether, the general formula R″-O-R or R″-S
-R (in the formula, R'', R represents a hydrocarbon group having 15 or less carbon atoms). Examples of AlR′pX ₃ -p include AlCl ₃ ,
Examples include AlR′Cl ₂ , and the like. Furthermore, it is particularly preferable that the solid titanium trichloride-based catalyst complex has a halo of maximum intensity at a position corresponding to the strongest peak position of α-type titanium trichloride in its X-ray diffraction pattern (near 2θ=329°). . Furthermore, when producing a solid titanium trichloride catalyst complex, 150
Those that have not been subjected to thermal history at temperatures exceeding 0.degree. C. are preferred. Furthermore, the cumulative pore volume between pore radius 20 Å and 500 Å measured by mercury borosimeter method is 0.02
cm ³ /g or more, especially 0.03 cm ³ /g to ^{0.15 cm 3} /g, which is characterized by a pore volume with an extremely fine pore diameter, in that there is no need to remove amorphous polymers. 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 temperature. (b) Solid titanium trichloride obtained by reducing titanium tetrachloride with an organic aluminum compound or metal aluminum is treated with a complexing agent and a halogen compound. It can be easily manufactured by methods such as. 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 the liberating agent, titanium tetrachloride, aluminum halide compounds, such as aluminum trihalide, alkyl aluminum dihalides, etc. are preferable. 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 at the same time, or the complexing agent treatment and the halogen compound treatment may be performed first. 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. In the present invention, the solid titanium trichloride-based catalyst complex obtained as described above is combined with an organoaluminum compound of the general formula (In the formula, R ¹ and R ² are hydrogen or have 1 carbon atom
~3 alkyl group, R ³ has 1 carbon atom
~20 alkyl groups. ) is mixed with the compound represented by ^The organoaluminum compound used as _a cocatalyst in this case has the general formula _AlR ⁴ n group, X is a halogen atom, m is
1.5≦m<3. ) Organoaluminum compounds represented by: Specific examples include dimethylaluminum chloride, diethylaluminum chloride,
Alkylaluminum halides such as diethylaluminium bromide and ethylaluminum sesquichloride, and mixtures thereof may also be used. Among these, preferred is dialkyl aluminum halide, and particularly preferred is diethyl aluminum chloride. general formula The compound represented by is methyl acrylate,
Ethyl, propyl, butyl esters; methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl esters of crotonic acid; methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl esters of isocrotonic acid; Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl ester; methyl, ethyl, butyl ester of tiglic acid; methyl angelic acid;
Ethyl, butyl ester; methyl and ethyl ester of α-ethyl acrylate, and the like. Particularly preferred are methyl, ethyl and butyl esters of methacrylic acid. The inert solvent used for mixing the solid titanium trichloride-based catalyst complex, the organoaluminum compound, and the unsaturated carboxylic acid ester may be the same as or different from that used for preparing the solid titanium trichloride. Inert hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons used in ordinary olefin polymerization are used. Normal hexane, normal heptane, cyclohexane, benzene, and toluene are preferably used. The amount of solid titanium trichloride-based catalyst complex dispersed in the inert solvent is not critical, but a certain concentration range is preferred. Usually inert solvent 1
The amount of titanium trichloride in the reaction mixture is preferably 1 to 100 g, preferably 5 to 50 g; if this amount is too low, the volume of the reactor required for this treatment becomes too large, which is industrially disadvantageous. If the concentration is too high, a non-uniform reaction may occur due to poor mixing, and the effects of the present invention will not be fully exhibited; however, a high concentration is usually selected within a range where sufficient stirring and mixing can be carried out. The amount of organoaluminum compound used is usually 0.1 to 10 molar ratio, preferably
The molar ratio is 0.2 to 2. The amount of the unsaturated carboxylic acid used is extremely important in achieving the effects of the present invention. Usually 0.01 to 1 molar ratio to solid titanium trichloride, preferably
The molar ratio is 0.02-0.2. If the amount is too large, the propylene polymerization activity of the propylene-containing solid titanium trichloride as a catalyst component will decrease, and the molecular weight distribution of the resulting propylene polymer will become broad, resulting in poor transparency of the film molded product. If it is too small, the effects of the present invention will not be fully exhibited. The temperature at which propylene is blown into the solid titanium trichloride-based catalyst complex, the organoaluminum compound, the unsaturated carboxylic acid, and the inert solvent is usually not particularly limited as long as it is lower than the temperature of the subsequent main polymerization. -70°C, preferably 5-60°C, more preferably 25-50°C. If this treatment temperature is too high, the yield of crystalline polymer obtained during polymerization of propylene with a catalyst containing the resulting propylene polymer-containing solid titanium trichloride, that is, the main polymerization, will not be sufficiently improved. Furthermore, if the treatment temperature is too low, the temperature difference between the treatment tank and the cooling water will be small, which will be industrially disadvantageous in terms of heat removal. In the present invention, propylene is introduced into the liquid phase or gas phase of a reactor containing a mixture consisting of the solid titanium trichloride catalyst complex, an inert solvent, an organoaluminum compound, and the unsaturated carboxylic acid. The rate of introduction is usually from 0.1 to 10 kg per hour, preferably from 0.2 to 5 kg per kg of solid titanium trichloride.
If the introduction rate is too high, it becomes difficult to control the reaction temperature, and if it is too low, the treatment time becomes longer, which is not preferred from an industrial perspective. Also, when introducing propylene, the most important thing is to keep the partial pressure of propylene in the gas phase of the reactor below 0.5Kg/ ^cm2 , preferably 0.2
Kg/cm ² or less, more preferably maintained at almost zero. If the propylene partial pressure is higher than this, not only will the objectives of the present invention of improving the bulk density and crystalline polymer yield of the polymer obtained by main polymerization of propylene not be sufficiently achieved, but also this polymer will The fixation of molded products increases. The propylene partial pressure is determined by the balance between the propylene introduction rate and the propylene absorption rate, and can be fully controlled as long as the above-mentioned suitable solid titanium trichloride is treated under suitable conditions. Although the propylene partial pressure may be monitored by analyzing the gas phase of the reactor, it is sufficient to monitor the pressure gauge attached to the gas phase. The above contact treatment of solid titanium trichloride and propylene produces a propylene polymer.
0.1 to 100 g, preferably 0.2 to 10 g of propylene polymer are produced. If the amount of propylene polymer is too small, the effect of the present invention cannot be exhibited, and if it is too large, the reactor volume becomes too large, which is industrially disadvantageous. In the present invention, hydrogen does not necessarily need to be present in the above-mentioned propylene contact treatment, and even if hydrogen is not used, no fixation will occur in the molded product from the polymer produced by main polymerization. however,
Adding hydrogen is also within the scope of this invention. Further, in the present invention, a small amount of other α-olefins such as ethylene and butene-1,4-methylpentene-1 may be used in combination with the introduced propylene. The propylene polymer-containing solid titanium trichloride produced by the above treatment can be used in the main polymerization as a slurry containing unreacted substances, inert solvents, etc., but it is usually removed from the liquid phase by decantation, filtration, or centrifugation. It is separated by a conventional separation means such as separation, and then washed several times by adding a solvent. As this solvent, it is advantageous to use the inert hydrocarbon solvent used in the above-mentioned propylene contact treatment. As described above, the propylene polymer-containing solid titanium trichloride used in the method of the present invention is obtained, and this material is used for propylene polymerization (main polymerization) by adding an organoaluminum compound as a catalyst.
Serve. As the organoaluminum compound as a cocatalyst added in the main polymerization _, those mentioned in the ^pretreatment step, that is, the compound represented by the general formula ( ₂ ), can be used. , R ⁵ represents a hydrocarbon group having 1 to 20 carbon atoms, and n represents a number of 1.9 to 21). Among these, diethylaluminum chloride in which R ⁵ is an ethyl group and n is 2 can also be used, but it is particularly preferable that R ⁵ is a normal propyl group or a normal hexyl group. The amount of the organoaluminum compound used is usually 0.1 to 100 times the amount of the titanium compound in the propylene polymer-containing titanium trichloride, preferably 2 to 100 times the amount by mole.
The amount is 10 moles. In the propylene polymer production method of the present invention, a sufficiently high yield of crystalline polymer can be obtained even with the catalyst consisting of the propylene polymer-containing solid titanium trichloride and an organoaluminum compound. In order to improve the propylene polymer, known third components such as electron-donating compounds and aromatic compounds may be added to the catalyst composition. In the main polymerization of propylene, the propylene polymer-containing solid titanium trichloride and an organoaluminum compound (a third component may be added as necessary) are simply mixed and used for polymerization.
The mixing method may be arbitrary. The polymerization method in the main polymerization can be carried out by known slurry polymerization, gas phase polymerization, etc. These polymerization methods may be continuous or batchwise, and the reaction conditions are 1 to 100 atmospheres, preferably 5 to 40 atmospheres, and 50 to 90°C, preferably 60 to 75°C. In slurry polymerization, the same inert solvent as the inert solvent used in the titanium trichloride pretreatment step described above is used as a polymerization catalyst, and specifically, hexane, heptane, cyclohexane, benzene, toluene, pentane, butane,
Examples include hydrocarbons such as propane, and propylene itself can also be used as a medium. Further, as a method for controlling the molecular weight of the produced polymer, it is also possible to appropriately add known molecular weight controlling agents such as hydrogen and diethylzinc to the polymerization reaction. Although propylene alone may be polymerized in the main polymerization of the present invention, propylene and other α-olefins may be used in combination. Other α-olefins are ethylene, butene-1,4-methylpentene-1, etc., as in the pretreatment step, and the amount thereof is small enough that the product does not lose its properties as a propylene polymer. For example, it is 10% by weight or less based on propylene. When propylene is polymerized according to the method of the present invention using solid titanium trichloride containing a propylene polymer as described above as a catalyst component, high catalyst efficiency and high crystalline polymer yield can be obtained. In a preferred example,
Catalyst efficiency, CE (total amount of propylene polymer produced per gram of titanium trichloride catalyst component (g))
23000gPP/gTiCl3 or _more , crystalline polymer yield (residual amount (wt%) when extracted with boiling n-hexane (boiling point 69℃) for 6 hours in an improved Soxhlet extractor) of 99.5% or more was easily achieved. Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.In the following examples and comparative examples, catalyst Efficiency is as described above, and crystalline polymer yield is expressed as the amount of amorphous polymer, ie, atactic polymer extracted when extracted with boiling n-hexane for 6 hours in a modified Soxhlet extractor.
MFI is a melt flow index,
Measured according to ASTM D-1238. The rigidity is
A tensile test was conducted on a pressed piece having a thickness of 1 mm in accordance with ASTM D-638, and the stress was expressed as yield point stress (Kg/cm ² ). Examples 1 to 2 (a) Preparation of solid titanium trichloride At room temperature, 5.15 g of purified toluene was placed in an autoclave with a capacity of 10 that was sufficiently purged with nitrogen, and while stirring, 651 g (5.0 mol) of n-butyl ether and 949 g of titanium tetrachloride ( 5.0 mol) and 286 g (24 mol) of ethylaluminum chloride were added to obtain a brown homogeneous solution. Then, the temperature is raised to 40°C. After 30 minutes, precipitation of purple fine particles is observed, but the temperature is maintained at 40°C for 2 hours. Then, an additional 450 g of TiCl ₄ was added and the temperature was raised to 96°C.
After being held at 96 DEG C. for about 1 hour, the granular purple solid was separated and washed with n-hexane to yield about 800 g of solid titanium trichloride. (b) Production of propylene polymer-containing titanium trichloride (pretreatment) Purified n-hexane (5) was placed in a 10 autoclave that had been sufficiently purged with nitrogen, and 195 g of diethylaluminium chloride and the solid titanium trichloride obtained in (a) above were added. 250 g (1.62 mol) of TiCl ₃ and 32 g (0.32 mol) of methyl methacrylate were charged, the temperature was maintained at 40° C., and 250 g of propylene gas was blown into the liquid phase for about 1 hour for contact treatment. Next, the solid components were allowed to settle and the supernatant liquid was removed by decantation and washed several times with n-hexane to obtain solid titanium trichloride containing a propylene polymer. (c) Polymerization of propylene 1500 ml of liquefied propylene, 155 mg of di-n-propyl aluminum chloride, and 20 mg of solid titanium trichloride containing the propylene polymer obtained in (b) above were placed in two autoclaves that had been thoroughly dried and purged with nitrogen (in terms of TiCl _{3 )} . 0.13 mmol) H ₂ was charged at 1.2 Kg/cm ² .
In Example 1, no third component was used, and in Example 2, 2.65 mg of phenyl acetate was used as the third component.
Polymerized for hours. After polymerization, unreacted monomer gas was purged, and the contents were taken out and dried to obtain a white powdery propylene polymer. A portion of the polymer was subjected to atactic polymer measurement, and BHT (2,6-di-t-butyl-p-methylphenol) was added to the remaining polymer at a concentration of 0.2% by weight based on the total polymer, and pelletized at 200°C. did. Next, a pressed piece with a thickness of 1 mm was obtained by pressing at 230°C, and a tensile test was conducted. The results of catalyst efficiency, amount of atactic polymer, and stress at yield point are shown in Table 1. Comparative Example 1 The same procedure as in Example 1 was carried out except that methyl methacrylate was not added in Example 1(b), and the results shown in Table 1 were obtained. Comparing Example 1 and Comparative Example 1, it is clear that the amount of atactic polymer produced and the rigidity of the product are excellent. Furthermore, it can be seen from Example 2 that the amount of atactic polymer produced can be extremely reduced. Examples 3-4 Propylene polymer-containing solid titanium trichloride was obtained in the same manner as in Example 1, except that the amount of methyl methacrylate was reduced to 16 g (0.16 mol) during the treatment in Example 1(b). Ta. Thoroughly dried purified n-
750 ml of hexane, 97 mg of diethylaluminum chloride, 25 mg (0.16 mmol) of the above propylene polymer-containing solid titanium trichloride in terms of TiCl ₃ , H ₂
0.5Kg/ ^cm2 was charged. In Example 3, no third component was used, but in Example 4, 7.4 mg of triphenyl phosphite was used as the third component. Propylene was charged at 70° C. so that the propylene partial pressure was 15 kg/cm ² , and polymerization was carried out for 5 hours while replenishing propylene to keep the pressure constant. Next, unreacted monomers were purged, the contents were taken out, and the entire amount of the solvent was evaporated to dry, to obtain a white powdery propylene polymer. Next, in the same manner as in Example 1, the first
The results in the table were obtained. Comparative Example 2 The results shown in Table 1 were obtained in the same manner as in Example 3, except that the pretreatment was performed without adding methyl methacrylate. A comparison between Example 3 and Comparative Example 2 shows that the present invention clearly reduces the amount of atactic polymer produced and improves the rigidity. Example 5 The same procedure as in Example 3 was carried out except that the polymerization temperature was changed to 65° C., and the results shown in Table 1 were obtained. This example also shows that a low amount of atactic polymer produced and high rigidity can be obtained. Comparative Example 3 The results shown in Table 1 were obtained in exactly the same manner as in Example 5, except that the pretreatment was performed without adding methyl methacrylate. A comparison between Example 5 and Comparative Example 3 clearly shows the effects of the present invention. Example 6 The same procedure as in Example 5 was carried out except that 45 g of n-butyl methacrylate was used instead of methyl methacrylate in the pretreatment, and the results shown in Table 1 were obtained. Comparative Example 4 The results shown in Table 1 were obtained in the same manner as in Example 5, except that 50 g of triphenyl phosphite was used in the pretreatment instead of methyl methacrylate. As a result, although high rigidity was achieved, the reduction in atactic polymer formation was not sufficient. In addition, the activity was lowered, and the catalyst efficiency was extremely low. Comparative Example 5 In Example 5, commercially available titanium trichloride (TiCl ₃ manufactured by Toho Titanium Co., Ltd.) was used as the solid titanium trichloride.
The results shown in Table 1 were obtained in the same manner as in Example 5 except that AA) was used. The results show that commercially available titanium trichloride cannot achieve high catalytic efficiency and high rigidity. The amount of atactic polymer produced is also quite large. Comparative Example 6 The solid titanium trichloride of Example 1(a) was subjected to polymerization in the same manner as in Example 5 without being pretreated, and the results shown in Table 1 were obtained. 【table】

[Brief explanation of drawings]

FIG. 1 is a flowchart illustrating one embodiment of the present invention.

Claims (1)

[Claims] 1(a) 150% from a liquid containing titanium trichloride liquefied in the presence of an ether or thioether
℃ or less, or (b) solid titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound or metal aluminum is obtained by a method in which solid titanium trichloride is treated with a complexing agent and treated with a halogen compound. A solid titanium trichloride-based catalyst complex having an aluminum content of 0.15 or less in atomic ratio of aluminum to titanium and containing a complexing agent is treated with an inert solvent, an organoaluminum compound and a general formula (In the formula, R ¹ and R ² are hydrogen or have 1 carbon atom
~3 alkyl group, R ³ has 1 carbon atom
~20 alkyl groups. 0.1 per gram of solid titanium trichloride on the complex by contacting with propylene in the presence of a compound represented by
Propylene alone or propylene containing small amounts of other α-olefins is produced using a catalyst comprising a propylene polymer-containing solid titanium trichloride obtained by producing ~100 g of propylene polymer and an organoaluminum compound. A method for producing a propylene polymer, characterized by polymerization. 2. The propylene polymer according to claim 1, wherein the solid titanium trichloride-based catalyst complex is precipitated at a temperature of 150°C or lower from a liquid containing titanium trichloride liquefied in the presence of ether. Method of manufacturing coalescence.