JPS59140206A - Production of propylene polymer - Google Patents

Abstract

PURPOSE:To obtain a crystalline polymer in high yields, by polymerizing propylene by using a highly efficient catalyst containing an organoaluminum compound and a propylene polymer and prepared by subjecting a specified solid titanium trichloride catalyst complex to a specified treatment. CONSTITUTION:A solid titanium trichloride catalyst complex having an alminum content, in terms of a Ti/Al atomic ratio, of at most 0.15 and containing a complexing agent is subjected to a contact treatment with propylene in the presence of an inert solvent, an organoaluminum compound (e.g., dimethylaluminum chloride) and a compound of the formula (wherein R<1> and R<2> are each a 1-3 C alkyl, and R<3> is a 1-20 C alkyl) to form 0.1-100g of propylene polymer per gram of solid titanium trichloride on the complex, whereby a catalyst containing an organoaluminum compound and a propylene polymer-containing solid titanium trichloride is formed. Propylene, alone or together with a small amount of an alpha-olefin, is polymerized by using the above catalyst.

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. . 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 non-quality polymer dissolved in the diluent. , it is possible to simplify the processing steps such as removing non-quality polymers,
It 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 high yields, and therefore, improving this problem is of extremely important industrial significance. It is. 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 for increasing the bulk density and stereoregularity of the resulting polymer. (Refer to Special Publication Akihiro 9-/Daza No. 6S)
. In this method, in the main polymerization after pretreatment, in order to obtain high catalyst efficiency, the bulk density and stereoregularity of the produced polymer, which rapidly decrease as the polymerization temperature rises, are relatively gently reduced. However, it was difficult to say that a satisfactory effect was necessarily obtained. In particular, the improvement effect was weak at a polymerization temperature of 60 to tOC, which is industrially realistic. Further, in this method, it is essential to have an appropriate amount of hydrogen present in order to prevent the formation of fish eyes in the molded product from the produced polymer. However, controlling it hydrogen is often difficult in practice.

In other words, too little hydrogen will increase fish eyes in the molded product, too much hydrogen will reduce the yield of crystalline polymer, and even if hydrogen and propylene are charged in specified amounts, the hydrogen concentration will change due to propylene absorption. It has the disadvantage of

Also 'ric, 4. //,? htct or ht
For propylene polymerization, propylene is slowly absorbed into an inert solvent dispersion obtained from a δ-type titanium trichloride composition obtained by treating β-type titanium trichloride containing cts with a complexing agent and pulverizing it, and an alkyl aluminum chloride. A method for activating a catalyst has been proposed (see Japanese Patent Publication No. Q3). However, this method does not allow a high propylene supply rate, and therefore requires an extremely long time 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, Tokko Akira! ;t-22g1t and special public show st
-t1giq is a method of pretreatment with propylene in the absence of hydrogen, and JP-A-53-1039Ir 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. Furthermore, the molded products obtained by these methods have the advantage of having extremely few fish eyes.

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. For example, even if the crystalline polymer yield is 99%,
That cannot be said to be sufficient. Furthermore, from the standpoint of quality, even higher rigidity is 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 also requires 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 present inventors have conducted extensive research and found that a specific solid titanium trichloride-based catalyst complex can be obtained by performing a specific treatment in the presence of a specific unsaturated carboxylic acid ester. It was discovered that high catalytic efficiency and extremely high yield of crystalline polymer can be obtained by polymerizing propylene using a catalyst system containing solid titanium trichloride containing a propylene polymer and an organoaluminum compound. did.

That is, the gist of the present invention is that the aluminum content is θ15 or less in terms of the atomic ratio of aluminum to titanium,
A solid titanium trichloride-based catalyst complex containing a complexing agent is mixed with an inert solvent, an organoaluminum compound, and the general formula (wherein R1 and R2 represent hydrogen or an alkyl group having 1 to 3 carbon atoms, and R3 represents a carbon atom). (representing an alkyl group having 1 to 20 atoms) is contacted with propylene in the presence of a compound represented by
Using a catalyst system comprising a propylene polymer-containing solid titanium trichloride and an organoaluminum compound obtained by producing a propylene polymer of 7' characterized by polymerizing propylene to
o l:” V-n polymer production method.

The present invention will be explained in detail below.

The solid titanium trichloride catalyst complex used in the present invention is:
The aluminum content is less than o, is, preferably less than O7, more preferably less than 0.02, in terms of the atomic ratio of aluminum to titanium, and contains a complexing agent. The content of the complexing agent is 0001 or more, preferably θ01 or more in molar ratio of the complexing agent to titanium trichloride in the solid titanium trichloride-based catalyst complex.

Specifically, titanium trichloride, the atomic ratio of aluminum to titanium in titanium trichloride is 0. /! Formula A less than or equal to i
Aluminum halide and titanium trichloride represented by LR' pXa-p (wherein, R' is a hydrocarbon group having 1 to 2θ carbon atoms, X is a halogen atom, and p is a number of O≦p≦2). Those containing a complexing agent with a molar ratio of 0.0θ1 or more, for example, the formula T I CL, .(AAR', X3-
,)ll・(C)t (wherein, R' is the number of carbon atoms/-2
0 hydrocarbon group, X is a halogen atom, p is a number of O≦p≦, C is a complexing agent, and B is 0.7
Ti (four components, AtR', X,

Components and Complexing Agents In addition to component C, a small amount of iodine, titanium trichloride in which part or all of the chlorine has been replaced with iodine or bromine, inorganic solids for carriers such as MgC4 and MgO, polyethylene, polypropylene. It may also contain olefin polymer powder such as. 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. Ethers or thioethers include those represented by the general formula R"-〇-R"' or R'-8-R"' (in the formula, B" and sneeze indicate a hydrocarbon group having a carbon number of is or less). can be mentioned. AtR', x3+,
Examples include htct, AtR'Ct2, and the like.

In addition, the solid titanium trichloride-based catalyst complex has an X-ray diffraction pattern with a halo of maximum intensity at a position corresponding to the strongest position of α-type titanium trichloride (near 20-3°). is particularly preferable. Further, it is preferable that the solid titanium trichloride-based catalyst complex is not subjected to thermal history at a temperature exceeding 15θC during production. Furthermore, the cumulative pore volume between the pore radius 2oX and 5ooX measured by the mercury porosimeter method is θθ2s/1 or more and <Kθ03crtl/F.
! -~θtscd/f, which is characterized by a pore volume with an extremely fine pore diameter, is preferable since it is not necessary to remove non-quality polymers.

However, such a solid titanium trichloride-based catalyst complex can be prepared by (a) precipitating titanium tetrachloride from a liquid containing titanium trichloride liquefied in the presence of an ether or thioether at a temperature of 15Oc or lower; Solid titanium trichloride obtained by reduction with organoaluminum compounds or metallic aluminum,
It can be easily produced by methods such as treatment with a complexing agent and treatment with a halogen compound.

In method (a), the following two methods can be used to obtain a liquid material containing liquefied titanium trichloride.

(A) Titanium tetrachloride? As a starting material, this is reduced with an organoaluminum compound in the presence of an ether or thioether and, if necessary, a suitable hydrocarbon solvent.

(B) A method in which solid titanium trichloride is used as a starting material and is treated with ether or thioether in the presence of a suitable hydrocarbon solvent as necessary.

There are no particular restrictions on the method for precipitating the fine particulate solid titanium trichloride catalyst complex, and the liquid may be used as it is or after adding a hydrocarbon diluent if necessary, i! Temperature below ioc, preferably q.

Precipitation is carried out by raising the temperature to ~10°C, particularly preferably from 6θ to 10°C. 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, such as aluminum trihalide, alkyl aluminum cybaride, 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), complexing agent C
Those exemplified as above are also listed. 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 may be performed first, and then the halogen compound treatment may be performed. Complexing agent treatment is
Usually, a complexing agent is added to solid titanium trichloride in a diluent in an amount of 0.2 to 3 moles relative to TiCl2, and -λθ~go℃
Do this at a temperature of After the complexing agent treatment, it is preferable to separate and wash the obtained solid. The halogen compound treatment is usually carried out in a diluent at a temperature of -10 to SθC. The amount of halogen compound used is usually /- for TlC1,
The amount is 70 times by mole, preferably 1 to S 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 mixed with an organoaluminum compound in an inert solvent.

(In the formula, R1 and R2 represent hydrogen or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 20 carbon atoms.) The organoaluminum compound used as a cocatalyst in this case has the general formula %% (21 (wherein, R4 is a saturated or unsaturated hydrocarbon group having a carbon atom number/~co), X is a halogen atom, m is is≦m (j
It is. ) Organoaluminum compounds represented by: Specific examples include dimethylaluminum chloride,
Alkylaluminum halides such as diethylaluminum chloride, diethylaluminum bromide, and ethylaluminum sesquichloride, and mixtures thereof may also be used. Among these, dialkyl aluminum halide is preferred, and diethyl aluminum chloride is particularly preferred.

Compounds represented by the general formula include methyl, ethyl, propyl, and butyl esters of acrylate; methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl esters of crotonate; methyl, ethyl, propyl, and isocrotonate; Butyl, pentyl, hexyl, heptyl, octyl ester; methyl, ether, furovir, butyl, pentyl, hexyl, heptyl methacrylate;
Octyl esters; methyl, ethyl, furoyl, butyl, hentyl, hexyl, heptyl, octyl esters of cinnamic acid; trimethyl, ethyl, phther esters of tiglic acid; methyl, ethyl, butyl esters of angelic acid;
Examples include methyl and ethyl esters of α-ethyl acrylic acid. 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 or different from that used for preparing the solid titanium trichloride. Normal olefin polymerization pressures are used and inert hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons are used. Normal hexane, normal hebutanecyclohexane, benzene, and drenka are preferably used.

The amount of solid titanium trichloride-based catalyst complex dispersed in the inert solvent is not critical, but preferably within a certain concentration range. Usually as titanium trichloride in an inert solvent lt/-100f, preferably S-Sθ? It is preferable that it be within the range of .If this 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 the organoaluminum compound used is usually 0.00% relative to solid titanium trichloride. /-/θ molar ratio, preferably 02~
The molar ratio is 2.

The amount of the unsaturated carboxylic acid used is extremely important in achieving the effects of the present invention. The molar ratio is usually θθ7-t<l, preferably 0.02 to 0.02 molar ratio to solid titanium trichloride. If the amount is too large, the propylene polymerization activity of the resulting propylene-containing solid titanium trichloride 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, but -lθ -70°C, preferably 5-60C1, more preferably 25-SOC.

If this treatment temperature is too high, the yield of crystalline polymer obtained during polymerization of propylene with a catalyst containing solid titanium trichloride containing a propylene polymer, that is, the main polymerization, may be insufficiently 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, an inert solvent, an organoaluminum compound, and the unsaturated carboxylic acid. The rate of introduction is usually 0, t-t kg per hour per liter of solid titanium trichloride, preferably θ! ; It is ky. 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 adjusting the propylene partial pressure, the most important thing is to keep the propylene partial pressure in the gas phase of the reactor below 05 #/cIIl, preferably below θ2 kg/cd, and more preferably at almost zero. That's true. If the propylene partial pressure is higher than this, not only will the objective of the present invention, which is to improve the bulk density and crystalline polymer yield of the polymer obtained by main polymerization of propylene, not only be achieved, but also the polymer The fish eye of the molded product has increased. 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 portion of the reactor, it is sufficient to monitor the pressure gauge attached to the gas phase portion.

A propylene polymer is produced by the above-mentioned contact treatment of solid titanium trichloride and propylene, and this contact treatment produces a propylene polymer of θl to /θol, preferably a2 to 109-, per solid titanium trichloride/f. Generate.

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 volume of the reactor becomes too large, which is disadvantageous industrially.

In the present invention, hydrogen does not necessarily need to be present in the above-mentioned propylene contact treatment, and even without the use of hydrogen, fish eyes will not occur in the molded product from the polymer produced by main polymerization.

However, adding hydrogen is also included within the scope of the present invention.

In addition, in the present invention, a small amount of other α-olefins such as ethylene, phthene/, +-methylpentene-1, etc. may be used in combination with the introduced propylene.The propylene polymer-containing solid titanium trichloride produced by the above treatment is not Although the slurry containing the reactants, inert solvent, etc. can be used as is for the main polymerization, it is usually decanted from the liquid phase.

Separated by normal separation means such as filtration and centrifugation,
Add more solvent and wash several times. As this solvent, it is advantageous to use the inert hydrocarbon solvent used in the above-mentioned propylene contact treatment.

The propylene polymer-containing solid titanium trichloride used in the method of the present invention is obtained in the manner described above, and an organoaluminum compound is added to the spun material to serve as a catalyst for propylene polymerization (main polymerization).

As the organoaluminum compound added in the main polymerization and serving as a cocatalyst, those mentioned in the above-mentioned pretreatment step, that is, the compound represented by the general formula (2), can be used. Represents a hydrocarbon group having 1 to 0 carbon atoms,
U represents a number from 19 to 1. ) Compounds represented by these are preferred. Among these, diethylaluminum chloride, in which R1' is an ethyl group and n is a tablet, is also sufficiently usable, but it is particularly preferable that R1+ is a normal propyl group or a ha normal hexyl group.

The amount of the organoaluminum compound used is usually 0.0% relative to the titanium compound of titanium trichloride containing propylene polymer. /~
lθO times the molar amount, preferably 2 to 10 times the molar amount.

In the propylene polymerization method of the present invention, a sufficiently high yield of crystalline polymer can be obtained using the catalyst consisting of the propylene polymer-containing solid titanium trichloride and an organoaluminum compound, but in order to increase the polymer yield or In addition, known third components such as electron-donating compounds and aromatic compounds can also be used in the catalyst composition in order to improve propylene polymerization.

In the main polymerization of propylene, the propylene polymer-containing solid titanium trichloride and the organoaluminum compound (*vcm three components may be added if necessary) are simply mixed and used for polymerization, but the mixing method is It's optional.

The polymerization method in the main polymerization can be carried out by known slurry polymerization, gas phase polymerization, etc. These polymerization methods may be either continuous or single batch, and the reaction conditions are 1 to 100 atmospheres,
Preferably under 5-ao'A pressure tv pressure,! ;0~90'
Q, preferably f'! , should be carried out in the range of 60 to 7 SC. In slurry polymerization, the same inert solvent as the inert solvent used in the titanium trichloride pretreatment step described above is used as the polymerization medium, and specifically, hexane, heptane, cyclohexane, benzene, toluene, pentane, phthane, and phthane. 4 hydrocarbons can be mentioned, and propylene itself can also be used as the 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.

In the main polymerization of the present invention, only propylene may be polymerized, but propylene and other α-olefins may be used in combination. Other α-olefins are ethylene, phthene/, F-methylpentene, etc., as in the pretreatment step, and these may be used in small amounts such that the product does not lose its properties as a propylene polymer, e.g. The amount of ON is % or less based on propylene.

When propylene is polymerized according to the method of the present invention using the propylene polymer-containing solid titanium trichloride 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 (titanium trichloride catalyst solid yield (residual amount (weight qb) when extracted with boiling n-hexane (boiling point xyC) for 6 hours in an improved Soxhlet extractor) qq, s weight % or more is easily achieved.

EXAMPLES The present invention will be explained in more detail with reference to eleven examples below, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

In the Examples and Comparative Examples below, the catalyst efficiencies are as described above, and the crystalline polymer yields are as follows: It is expressed as the amount of atactic polymer extracted. MFI is melt flow index and was measured according to ASTM D-123g. The rigidity was determined by tensile testing a 7M thick press piece according to ASTM D-43g, and its yield point stress (lcp/
Cr1L').

Example/-2 (,) Preparation of solid titanium trichloride At room temperature, 15 tons of purified toluene was placed in an autoclave with a capacity of 102 which was sufficiently purged with nitrogen, and under stirring, n
-Butyl ether 6j/ii' (0 moles), titanium tetrachloride 91I9f (0 moles) and 2 gAf (2.11 moles) of diethylaluminium chloride were added to obtain a brown homogeneous solution. Then, the temperature is raised to t6oc. After 30 minutes, the precipitation of purple fine particles was observed, but the Hiro OC was kept for 2 hours. Then DaSOf
After further addition of TlC14'y, the granular purple solid was separated and n
-Washing with hexane gave approximately gooy solid titanium trichloride.

(b) Production of titanium trichloride containing propylene polymer (
Pretreatment) Purified n-hexane was added to an iot autoclave which had been sufficiently converted to carbon dioxide, and diethylaluminum chloride 1
951 and the solid titanium trichloride obtained in (,) above was converted into Ti(
25θy- (1A2 mol) as A3 and methacrylic acid 32f (032 mol) were kept at 0°C, the temperature at which they were charged, and propylene gas 23Of'lf 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 In a 2-ton autoclave that was thoroughly dried and purged with nitrogen, 300 ml of liquefied propylene, di-normal globyl aluminum chloride/js3m9, and the propylene polymer-containing solid titanium trichloride obtained in (b) above were added. ,
Converted to θ1ψ (013 mmol) H2? l
2 kf/crtE was charged. In Example 1, no third component was used, and in Example 2, phenyl acetate 2 was used as the third component.
．． Polymerization was carried out using 6S da at 7θC for 5 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 atactic polymer was measured, and the remaining polymer was treated with BHT (2
, t-di-t-butyl-p-methylphenol) was added in an amount of t% by weight of θλ based on the total polymer, and pelletized at 200C. Then 230C press to make thickness/ifi
A pressed piece was obtained and subjected to a tensile test. 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 t(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.

Moreover, it is clear from the Examples that the amount of atactic polymer produced can be extremely reduced.

Examples 3 to Hong Example i Except for reducing the amount of methyl methacrylate in the treatment of (b) to 16 animals, i6 mol)
Propylene polymer-containing solid titanium trichloride was obtained in the same manner as above.

Purified n-hex 7 in a thoroughly dried 2t autoclave
730ml, diethyl aluminum chloride work lr
In Example Q and the propylene polymerization potion Example 3 described above, no third component was used, but in Example G, triphenyl phosphite 7'1■ was used as the third component. Charge propylene so that the propylene partial pressure is 15 kg/mK at 70°C, and add propylene to keep the pressure constant.
Time polymerization was performed. 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. Then, the results shown in Table 1 were obtained in the same manner as in Example.

Comparative Example 2 The results shown in Table 1 were obtained in exactly 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 3 shows that the present invention clearly reduces the amount of atactic polymer produced and improves rigidity.

Example S Example 3 The results shown in Table 1 were obtained in the same manner as in Example 3 except that the polymerization temperature was 45'C in VC. It can be seen from this example that a low amount of atactic polymer produced and a low tube stiffness can be obtained.

Comparative Example 3 Comparative Example 1 was carried out in exactly the same manner as in Example S, except that the pretreatment was performed without adding methyl methacrylate in Example S.
Obtained the results in the table.

A comparison between Example S and Comparative Example 3 clearly shows the effects of the present invention.

Example 6 In Example S, n-butyl methacrylate was used instead of methyl methacrylate. Example 5 was carried out in exactly the same manner as in Example 5, except that the pretreatment was carried out using the following methods, and the results shown in Table 1 were obtained.

Comparative Example 5 The results shown in Table 1 were obtained in the same manner as in Example S, except that the pretreatment was performed using triphenyl phosphite 5oy- instead of methyl methacrylate. As a result, although stiffness was achieved, the reduction in atactic polymer formation was not sufficient. Moreover, the activity was decreased and the catalyst efficiency was extremely low.

Comparative Example S The results shown in Table 1 were obtained in the same manner as in Example S, except that in Example 5, commercially available titanium trichloride (TiC2°・AA manufactured by Toho Titanium ■) was used as the solid titanium trichloride.

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 Gal Example/ Solid titanium trichloride (-) was subjected to the same polymerization as in Example S without being pretreated, and the results shown in Table 1 were obtained.

Procedural amendment book Showa 5g year! Kazuo Wakasugi, Commissioner of the Japan Patent Office, May 23rd, 1 Case Description Showa Str. Patent Application No. 74'93
t No. 2 Name of the invention Process for producing propylene polymer 3 Person making the amendment Applicant (JRI) Mitsubishi Chemical Industries, Ltd. 4 Agent 〒100 (1) CjH on page 1≠ line 1.2 of the specification =C-C0OR" j octyl ester;" is deleted.

(3) Page 1, line 20, page 1j, line g, 2
Page j, line 1, page 2, line 20, page 27, line 2,
λth page 1st line, 29th page 2nd line, 73rd line, 3rd/page 3rd line, Otsu, ? In the , //, /≠ lines, "methacrylic acid" should be corrected to "methacrylic acid."

that's all

Claims (2)

[Claims] (1) A solid titanium trichloride-based catalyst complex having an aluminum content of 41S or less in the atomic ratio of aluminum to titanium and containing a complexing agent is mixed with an inert solvent, an organoaluminum compound and a general formula (in the formula, R1 and R2 represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 20 carbon atoms. Titanium trichloride/y 0. t-/
00f! - Containing propylene alone or a small amount of other α-olefin using a catalyst containing a propylene polymer-containing solid titanium trichloride obtained by producing a propylene polymer of -J
= A method for producing a propylene polymer, characterized by polymerizing nylpropylene. (2) A solid titanium trichloride-based catalyst complex is produced from a liquid containing titanium trichloride liquefied in the presence of ether.
A method for producing a propylene polymer according to claim 1, wherein the propylene polymer is precipitated at a temperature of 0° C. or lower.