JPH0780960B2 - High-rigidity polypropylene manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing high-rigidity polypropylene. More specifically, it relates to a method for producing a high-rigidity polypropylene having extremely excellent transparency.

[Conventional technology and its problems]

The Applicant has previously proposed a method for producing a high-rigidity polypropylene using a catalyst obtained by combining a titanium trichloride composition obtained by a specific method with a specific use ratio of an organoaluminum compound and an aromatic carboxylic acid ester. (Japanese Patent Application Laid-Open No. 58-104,907, hereinafter referred to as invention of prior application) is proposed. According to the method of the invention of prior application, a conventionally known method can be used without adding any special additive. It has become possible to produce a polypropylene that can provide a molded product having significantly higher rigidity than the obtained polypropylene.

However, although the polypropylene obtained by the method of the invention of the prior application has high rigidity as described above, it is semi-transparent, so the commercial value may be impaired in the field of use, and improvement in transparency is desired. It was rare.

On the other hand, as an attempt to improve the transparency of polypropylene and another attempt to improve the rigidity, a multistage polymerization method in which a small amount of vinylcyclohexane is polymerized before the polymerization of propylene (JP-A-60-139,710) is proposed. However, when the present inventors produced polypropylene according to the proposed method, not only the polymerization activity of propylene is lowered but also a bulk polymer is produced, so in an industrial long-term continuous polymerization method. Was an unacceptable method. Further, the rigidity of the obtained polypropylene was lower than that of the polypropylene obtained by the method of the prior invention, which was insufficient. Further, when the polypropylene was processed into a film, although a certain improvement in transparency was observed, a large number of voids were generated in the film,
It was a loss of product value.

Further, as a similar technique, a method of polymerizing propylene using the catalyst component obtained by adding a vinylcyclohexane polymer during the production of a transition metal catalyst component for producing propylene (Japanese Patent Laid-Open No. 63-69,809). Although proposed, the proposed method requires a separate step for producing a vinylcyclohexane polymer, and therefore not only has an industrial disadvantage, but also has an insufficient rigidity similar to that of the above-described multistage polymerization technique, There was a problem of void generation in the film.

The present inventors diligently studied a method for producing a high-rigidity polypropylene having improved transparency, which solves the problems of the previously filed invention and the multi-stage polymerization technique.
As a result, polypropylene was prepared by using a catalyst formed by combining a titanium trichloride composition containing a specific polymer having a saturated cyclic structure by a specific method, an organoaluminum compound, and a specific amount of an aromatic carboxylic acid ester. In the case of producing, it solves the above-mentioned problems in production and quality of the multi-stage polymerization technique, and has not only excellent transparency as compared with polypropylene obtained by the method of the prior invention, but also, The inventors have found that the rigidity is further improved, and have reached the present invention.

As is clear from the above description, an object of the present invention is to provide a method for producing a high-rigidity polypropylene having extremely few voids and having extremely excellent transparency. Another object is to provide a high-rigidity polypropylene having remarkably excellent transparency and having extremely few voids.

[Means for Solving the Problems]

 The present invention has the following configurations.

(1) A solid product (II) obtained by reacting titanium tetrachloride with an organoaluminum compound (A ₁ ) or a reaction product (I) of an organoaluminum compound (A ₁ ) and an electron donor (B ₁ ). ) Is polymerized with a saturated ring hydrocarbon monomer having 5 to 20 carbon atoms which may contain silicon and has a saturated cyclic structure of a hydrocarbon which may contain silicon and a c = c bond. , And the electron donor (B ₂ ) and Periodic Table III
~ Titanium trichloride composition (III) obtained by the method of reacting with a halide of a Group VI element, wherein 0.01% by weight to 99% by weight of the polymer of a saturated ring hydrocarbon monomer
The titanium trichloride composition (III) contained by weight% is combined with the organoaluminum compound (A ₂ ) and the aromatic carboxylic acid ester (E) to obtain the aromatic carboxylic acid ester (E) and the titanium trichloride composition. The molar ratio of the compound (III) is (E) / (II
I) = 0.1 to 10.0, and the organoaluminum compound (A ₂ )
And the titanium trichloride composition (III) in a molar ratio of (A ₂ ) / (I
II) A method for producing high-rigidity polypropylene, which comprises polymerizing propylene using a catalyst of 0.1 to 200.

(2) The general formula of the organoaluminum compound (A ₁ ) is
A1R ¹ _p R ² _{p ′} X _{3- (p + p ′)} (In the formula, R ¹ and R ² represent a hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group, and X represents a halogen; p, p ′
Represents an arbitrary number of 0 <p + p ′ ≦ 3. The manufacturing method of said 1st item using the organoaluminum compound represented by these.

(3) The production method according to the above item 1, wherein a dialkylaluminum monohalide is used as the organoaluminum compound (A ₂ ).

(4) In place of the titanium trichloride composition (III), the titanium trichloride composition (III) is combined with an organoaluminum compound, and the catalyst component pre-activated with a small amount of α-olefin is used. The manufacturing method according to item.

(5) The production method as described in the above item 1, wherein the relation between the isotactic pentad fraction (P) of polypropylene and MFR is within the range of 1.00 ≧ P ≧ 0.015 1og MFR + 0.955.

The structure of the present invention will be described in detail below.

The titanium trichloride composition (III) used in the present invention has a saturated cyclic structure of a hydrocarbon which may contain silicon,
0.01% by weight of a specific polymer which may contain silicon (hereinafter sometimes abbreviated as a saturated ring polymer).
This is a titanium trichloride composition (III) containing 99% by weight, and its production method will be described.

The titanium trichloride composition (III) is produced as follows. First, a reaction product (I) is obtained by reacting an organoaluminum compound (A ₁ ) with an electron donor (B ₁ ) and a solid product obtained by reacting this (I) with titanium tetrachloride. (II) or a solid product (II) obtained by reacting an organoaluminum compound (A ₁ ) with titanium tetrachloride
Is a saturated ring hydrocarbon monomer having 5 to 20 carbon atoms and optionally having silicon, which has a saturated cyclic structure of a hydrocarbon which may contain silicon and a c = c bond.
It may be abbreviated as a saturated ring-containing monomer. After the polymerization treatment with ( ₁ ), the electron donor (B ₂ ) is further reacted with the electron acceptor to obtain the titanium trichloride composition (III) used in the present invention.

In the present invention, "polymerizing" means contacting the saturated ring monomer with the solid product (II) under a condition under which the saturated ring monomer can be polymerized to polymerize the saturated ring monomer. By this polymerization treatment, the solid product (II) is in a state of being coated with the polymer.

The above-mentioned reaction between the organoaluminum compound (A ₁ ) and the electron donor (B ₁ ) is carried out in the solvent (D) at −20 ° C. to 200 ° C., preferably −10 ° C. to 100 ° C. for 30 seconds to 5 hours. . There is no limitation on the order of addition of the organoaluminum compound (A ₁ ), (B ₁ ), and (D), and the amount ratio used is from 0.1 mol of the electron donor (B ₁ ) to 1 mol of the organoaluminum compound (A ₁ ). 8 mol, preferably 1-4 mol, solvent 0.5 L-5 L, preferably
It is 0.5L-2L.

Thus, the reaction product (I) is obtained. The reaction product (I) can be used for the next reaction in a liquid state as it is after completion of the reaction (sometimes referred to as the reaction product liquid (I)) without separation.

The reaction product (I) and titanium tetrachloride or the solid product (II) obtained by reacting the organoaluminum compound (A ₁ ) and titanium tetrachloride are polymerized with a saturated ring monomer. As the method, a reaction product (I) or a solid product (II) is polymerized by adding a saturated ring-containing monomer in any process of the reaction between the organoaluminum compound (A ₁ ) and titanium tetrachloride. Method, the reaction product (I), or after the reaction of the organoaluminum compound (A ₁ ) with titanium tetrachloride, a saturated ring-containing monomer is added to give a solid product (I
A method of polymerizing I), and a reaction product (I),
Alternatively, after the reaction between the organoaluminum compound (A ₁ ) and titanium tetrachloride is completed, the liquid portion is separated and removed by filtration or decantation, and the obtained solid product (II) is suspended in a solvent, and the organic compound is further added. Aluminum compound (A ₁ ),
There is a method in which a saturated ring-containing monomer is added and a polymerization treatment is carried out.

The reaction of the reaction product (I) or the organoaluminum compound (A ₁ ) with titanium tetrachloride is carried out at −10 ° C. to 200 ° C. regardless of the addition or non-addition of the saturated ring monomer in any process of the reaction. C., preferably 0 to 100.degree. C. for 5 minutes to 10 hours.

Although it is preferable not to use a solvent, an aliphatic or aromatic hydrocarbon can be used. The mixing of (I) or the organoaluminum compound (A ₁ ), titanium tetrachloride, and the solvent may be carried out in any order, and addition of the saturated ring-containing monomer may also be performed.
You can go at any stage.

The mixing of the total amount of (I) or the organoaluminum compound (A ₁ ), titanium tetrachloride, and the solvent is preferably completed within 5 hours, and the reaction is performed during the mixing. It is preferable to continue the reaction within 5 hours after mixing the whole amount.

The amount of each used in the reaction is 1 to 1 mol of titanium tetrachloride, the solvent is 0 to 3,000 ml, and the reaction product (I) or the organoaluminum compound (A ₁ ) is in the (I) or the (A ₁ ). The ratio of the number of A1 atoms to the number of Ti atoms in titanium tetrachloride (A1 / Ti) is 0.05 to 10, preferably 0.06 to 0.3.

The polymerization treatment with the saturated ring-containing monomer is carried out when the saturated ring-containing monomer is added at any stage of the reaction between the reaction product (I) or the organoaluminum compound (A ₁ ) and titanium tetrachloride. When the saturated ring-containing monomer is added after the reaction of (I) or the organoaluminum compound (A ₁ ) with titanium tetrachloride, the reaction temperature is 0 ° C to 90 ° C for 1 minute to 10 hours, and the reaction pressure is Under atmospheric pressure to 10 kgf / cm ² G, 0.01 g to 100 kg of the saturated ring-containing monomer is used per 100 g of the solid product (II) to obtain the final titanium trichloride composition (III). Polymerization is performed so that the content of the saturated ring polymer is 0.01% by weight to 99% by weight.

If the content of the saturated ring-containing polymer is less than 0.01% by weight, the effect of improving transparency and crystallinity of the polypropylene produced by using the obtained titanium trichloride composition is insufficient, and 99% by weight is also added. If it exceeds, the improvement effect is not remarkable and it is economically disadvantageous.

Polymerization treatment with a saturated ring monomer is obtained after the reaction of the reaction product (I) or the organoaluminum compound (A ₁ ) with titanium tetrachloride is completed, and the liquid portion is separated and removed by filtration or decantation. When the obtained solid product (II) is suspended in a solvent, the solid product (II) is 100 g.
In contrast, 100 ml to 5,000 ml of solvent, organoaluminum compound
0.5g to 5,000g is added, reaction temperature is 0 ℃ to 90 ℃, 1 minute to 10 hours, and reaction pressure is from atmospheric pressure to 10kgf / cm ² G. 0.01g to 100kg per 100g of solid product (II). Polymerization is carried out using the above saturated ring-containing monomer so that the content of the saturated ring polymer in the final titanium trichloride composition (III) will be 0.01% by weight to 99% by weight.

The solvent is preferably an aliphatic hydrocarbon, and the organoaluminum compound was used for obtaining the reaction product (I) or used for the reaction with titanium tetrachloride directly without reacting with the electron donor (B ₁ ). It may be the same as or different from the one.

After completion of the reaction, the liquid portion is separated and removed by filtration or decantation, and after further washing with a solvent,
The obtained solid product subjected to the polymerization treatment (hereinafter sometimes referred to as solid product (II-A)) may be used in the next step as it is in a state of being suspended in a solvent, and further dried to give a solid. You may take it out and use it.

The solid product (II-A) is then reacted with an electron donor (B ₂ ) and an electron acceptor (F). This reaction can be carried out without using a solvent, but using an aliphatic hydrocarbon gives preferable results.

The amount used is 100 g of solid product (II-A),
(B ₂ ) 0.1 g to 1,000 g, preferably 0.5 g to 200 g, (F) 0.
1g-1,000g, preferably 0.2g-500g, solvent 0-3,000m
l, preferably 100-1,000 ml.

As a reaction method, a solid product (II-A) is reacted with an electron donor (B ₂ ) and an electron acceptor (F) at the same time, and after (II-A) is reacted with (F), ( a method of reacting B _2), was reacted with (B ₂₎ to (II-a),
There are a method of reacting (F) and a method of reacting (B ₂ ) with (F) and then reacting with (II-A), but any method may be used.

The reaction conditions are 40 ° C. to 20 ° C. in the above method.
It is desirable to carry out the reaction at 0 ° C., preferably 50 ° C. to 100 ° C. for 30 seconds to 5 hours, and in the method of (II-A) and (B ₂ ) the reaction is performed at 0 ° C. to 50 ° C. for 1 minute to 3 hours. After the reaction, (F) is reacted under the same conditions as described above.

In the other method, (B ₂ ) and (F) are heated at 10 ℃ to 100 ℃.
After reacting for 30 minutes to 2 hours, cool to 40 ° C or lower (II
After the addition of -A), the reaction is carried out under the same conditions as above.

After the reaction of the solid products (II-A), (B ₂ ) and (F) is completed, the liquid portion is separated and removed by filtration or decantation, and then the washing with a solvent is repeated to obtain the saturated product used in the present invention. A titanium trichloride composition (III) containing 0.01% by weight to 99% by weight of a ring polymer is obtained.

The organoaluminum compound (A ₁ ) used in the production of the titanium trichloride composition (III) used in the present invention has a general formula of A ₁ R ¹ _p R ² _{p ′} X _{3 − (p + p ′)} (wherein R ¹ , R ² represents a hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group, X represents a halogen, and p,
p'represents an arbitrary number of 0 <p + p'≤3. ) Is used.

Specific examples thereof include trimethyl aluminum, triethyl aluminum, tri n-propyl aluminum, tri n-butyl aluminum, tri i-butyl aluminum, tri n-hexyl aluminum, tri i-hexyl aluminum, tri 2-methylpentyl aluminum,
Trialkylaluminums such as tri-n-octylaluminum and tri-n-decylaluminum, diethylaluminum monochloride, di-n-propylaluminum monochloride, di-butylaluminium monochloride, diethylaluminum monofluoride, diethylaluminum monobromide, Dialkyl aluminum monohalides such as diethyl aluminum monoiodide, dialkyl aluminum hydrides such as diethyl aluminum hydride, alkyl aluminum sesquihalides such as methyl aluminum sesquichloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, i-butyl aluminum dichloride, etc. Monoalkyl aluminum dihalides of Monoethoxy diethylaluminum, alkoxyalkyl aluminum such as diethoxy monoethyl aluminum can also be used to. Two or more kinds of these organoaluminum compounds may be mixed and used.

As the electron donor used in the present invention, various ones shown below are shown. As (B ₁ ) and (B ₂ ), ethers are mainly used, and other electron donors are shared with ethers. Is preferred. What is used as an electron donor is an organic compound having any atom of oxygen, nitrogen, sulfur and phosphorus, that is, ethers, alcohols, esters, aldehydes, fatty acids, ketones, nitriles,
Amines, amides, urea or thioureas, isocyanates, azo compounds, phosphines, phosphites,
Examples include phosphanites, hydrogen sulfide or thioethers, and thioalcohols. Specific examples include diethyl ether, di-n-propyl ether, di-n-butyl ether, diisoamyl ether, di-n-pentyl ether,
Di n-hexyl ether, di i-hexyl ether, di n-octyl ether, di i-octyl ether, di n
-Ethers such as dodecyl ether, diphenyl ether, ethylene glycol monoethyl ether, tetrahydrofuran, methanol, ethanol, propanol,
Alcohols such as butanol, pentanol, hexanol, octanol, phenol, cresol, xylenol, ethylphenol, naphthol, or phenols, methyl methacrylate, ethyl acetate, butyl formate, amyl acetate, vinyl butyrate, vinyl acetate, ethyl benzoate. , Propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, 2-ethylhexyl toluate, methyl anisate, ethyl anisate, propyl anisate, ethyl cinnamate, Esters such as methyl naphthoate, ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate and ethyl phenylacetate, aldehydes such as acetaldehyde and benzaldehyde, formic acid Acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, acrylic acid, fatty acids such as maleic acid,
Aromatic acids such as benzoic acid, methyl ethyl ketone, methyl isobutyl ketone, ketones such as benzophenone, nitriles such as acetonitrile, methylamine, diethylamine, tributylamine, triethanolamine, β
(N, N-dimethylamino) ethanol, pyridine, quinoline, α-picoline, 2,4,6-trimethylpyridine, N,
Amines such as N, N ′, N′-tetramethylethylenediamine, alinine and dimethylaniline, formamide,
Hexamethylphosphoric acid triamide, N, N, N ′, N ′, N ″ -pentamethyl-N′-β-dimethylaminomethylphosphoric acid triamide, octamethylpyrophosphoramide and other amides, N, N, N ′ Urea such as -N'-tetramethylurea, phenyl isocyanate, isocyanate such as toluyl isocyanate, azo compound such as azobenzene, ethylphosphine, triethylphosphine, tri-n-butylphosphine, tri-n-octylphosphine, triphenylphosphine, Phosphines such as triphenylphosphine oxide, dimethylphosphite, di-n-octylphosphite, triethylphosphite, tri-n-butylphosphite, phosphites such as triphenylphosphite, ethyldiethylphosphinite, ethyldibutylphosphite Fanite, Examples include phosphinites such as phenyldiphenylphosphinite, thioethers such as diethyl thioether, diphenyl thioether, methylphenyl thioether, ethylene sulfide and propylene sulfide, thioalcohols such as ethyl thioalcohol, n-propyl thioalcohol and thiophenol. These electron donors can also be used as a mixture.
The electron donor (B ₁ ) and the solid product (II-A) (B ₂ ) for obtaining the compound may be the same or different.

The electron acceptor (F) used in the present invention is a periodic table III to VI.
It is represented by a halogen compound of a group element. Specific examples include anhydrous aluminum chloride, silicon tetrachloride, stannous chloride, stannic chloride, titanium tetrachloride, zirconium tetrachloride, phosphorus trichloride, phosphorus pentachloride, vanadium tetrachloride, antimony pentachloride and the like. These can also be used as a mixture. Most preferred is titanium tetrachloride.

The following solvents are used. Examples of the aliphatic hydrocarbon include n-pentane, n-hexane, n-heptane, n-octane, i-octane and the like, and carbon tetrachloride, chloroform instead of or together with the aliphatic hydrocarbon. It is also possible to use halogenated carbon hydrogen such as dichloroethane, trichloroethylene, and tetrachloroethylene. As aromatic compounds, aromatic hydrocarbons such as naphthalene, and mesitylene which is a derivative thereof,
Durene, ethylbenzene, isopropylbenzene, 2
Alkyl-substituted compounds such as -ethylnaphthalene and 1-phenylnaphthalene, and halides such as monochlorobenzene, chlorotoluene, chlorxylene, chloroethylbenzene, dichlorobenzene and bromobenzene are shown.

The saturated ring-containing monomer used in the polymerization treatment has a saturated cyclic structure of a hydrocarbon which may contain silicon and a saturated ring having 5 to 20 carbon atoms which may contain silicon and has a c = c bond. It is a hydrocarbon monomer. As a concrete example,
Vinylcyclopropane, vinylcyclobutane, vinylcyclopentane, 3-methylvinylcyclopentane, vinylcyclohexane, 2-methylvinylcyclohexane,
In addition to vinylcycloalkanes such as 3-methylvinylcyclohexane, 4-methylvinylcyclohexane and vinylcycloheptane, allylcyclopentane and allylcycloalkanes such as allylcycloheptane, cyclotrimethylenevinylsilane, cyclotrimethylenemethylvinylsilane, Cyclotetramethylene vinyl silane, cyclotetramethylene methyl vinyl silane, cyclopentamethylene vinyl silane, cyclopentamethylene methyl vinyl silane, cyclopentamethylene ethyl vinyl silane,
Within a saturated cyclic structure such as cyclohexamethylenevinylsilane, cyclohexamethylenemethylvinylsilane, cyclohexamethyleneethylvinylsilane, cyclotetramethyleneallylsilane, cyclotetramethylenemethylallylsilane, cyclopentamethyleneallylsilane, cyclopentamethylenemethylallylsilane, cyclopentamethyleneethylallylsilane A saturated ring monomer having a silicon atom, cyclobutyldimethylvinylsilane, cyclopentyldimethylvinylsilane, cyclopentylethylmethylvinylsilane, cyclopentyldiethylvinylsilane, cyclohexyldimethylvinylsilane, cyclohexylethylmethylvinylsilane, cyclobutyldimethylallylsilane, cyclopentyldimethylallylsilane,
Examples thereof include cyclohexyldimethylallylsilane, cyclohexylethylmethylallylsilane, cyclohexyldiethylallylsilane, 4-trimethylsilylvinylcyclohexane, 4-trimethylsilylallylcyclohexane, and other saturated ring-containing monomers having a silicon atom outside the saturated cyclic structure. One or more kinds of these saturated ring-containing monomers are used.

A catalyst for use in the present invention, which is obtained by combining the titanium trichloride composition (III) obtained as described above, an organoaluminum compound (A ₂ ) and an aromatic carboxylic acid ester (E) in a predetermined amount described below. Or more preferably α
-Use as a catalyst pre-activated by reacting an olefin.

The polymerization mode of propylene polymerization using the above catalyst is not limited, and it can be suitably carried out not only in liquid phase polymerization such as slurry polymerization and bulk polymerization but also in gas phase polymerization. A catalyst obtained by combining a titanium trichloride composition (III) with an organoaluminum compound (A ₂ ) and an aromatic carboxylic acid ester (E) is sufficiently effective for slurry polymerization or bulk polymerization, but it is effective for gas phase polymerization. When used, the titanium trichloride composition (III) is replaced with a titanium trichloride composition (III) in combination with an organoaluminum compound.
It is desirable to use a higher activity catalyst component that has been preactivated by reacting an olefin. When performing gas phase polymerization following slurry polymerization or bulk polymerization, even if the catalyst initially used is the former, it is the same as the latter catalyst because the reaction of propylene has already been carried out during gas phase polymerization. And an excellent effect can be obtained.

Pre-activation is based on 1 g of titanium trichloride composition (III),
Organoaluminum compound 0.005 g to 500 g, solvent 0 to 50 l,
Hydrogen 0 to 1,000 ml, and α-olefin 0.01 g to 5,000
g, preferably 0.05 g to 3,000 g, and reacted with α-olefin at 0 ° C. to 100 ° C. for 1 minute to 20 hours to give 0.01 g to 2,000 g, preferably 0.05 to 1 g of the titanium trichloride composition (III). g ~ 2
It is desirable to polymerize 00 g of α-olefin.

The reaction of α-olefin for pre-activation is carried out in an aliphatic or aromatic hydrocarbon solvent such as n-pentane, n-hexane, n-heptane or toluene, or in a liquefied propylene or liquefied butene without solvent. It can also be carried out in a liquefied α-olefin such as -1 or the like, an α-olefin such as ethylene or propylene can be reacted in a gas phase, or can be carried out in the presence of an α-olefin polymer and hydrogen in advance. It is also possible to add the aromatic carboxylic acid ester (E) in advance in the preliminary activation.

Examples of the α-olefin used for preactivating include ethylene, propylene, butene-1, pentene-
1, straight-chain monoolefins such as 1, hexene-1, heptene-1, octene-1, 4-methyl-pentene-1,2-
Branched chain mono-olefins such as methyl-pentene-1 are listed, and one or more kinds of α-olefins are used. Further, as the organoaluminum compound, the same ones as the above-mentioned (A ₁ ) can be used, but a dialkylaluminum monohalide similar to the below-mentioned ((A ₂ ) is preferably used.

After the preactivation reaction is completed, the catalyst prepared by adding a predetermined amount of the aromatic carboxylic acid ester (E) to the preactivation catalyst component slurry can be used as it is for the polymerization of propylene, or a coexisting solvent can be used. The unreacted α-olefin and the organoaluminum compound are removed by filtration or decantation, and dried powder or a suspension is prepared by adding a solvent to the powder and the organoaluminum compound (A ₂ ) And an aromatic carboxylic acid ester (E) as a catalyst, and a method of providing for the polymerization of propylene, a coexisting solvent, and an unreacted α-olefin are evaporated by vacuum distillation, an inert gas flow, or the like. except Te, and a state of being suspended by adding a solvent to the powder or granular material or powder granules, the organic aluminum compound optionally in the ones (a ₂₎ And pressurizing, further as a catalyst in combination with aromatic carboxylic acid ester (E), it is also possible to use in the polymerization of propylene.

Regarding the amount of the titanium trichloride composition (III), the organoaluminum compound (A ₂ ) and the aromatic carboxylic acid ester (E) used during the polymerization of propylene,
The aromatic carboxylic acid ester (E) and the titanium trichloride composition (III) have a molar ratio (E) / (III) of 0.1 to 10.0, the organoaluminum compound (A ₂ ) and the titanium trichloride composition. the molar ratio of _{(III) (a 2) /} (III) is 0.1 to 200, preferably used within an amount of 0.1 to 100.

If the addition amount of the aromatic carboxylic acid ester (E) is small, the improvement of isotacticity is insufficient, so that the rigidity is not high, and if the addition amount is too large, the polymerization activity is lowered, which is not practical.
The number of moles of the titanium trichloride composition (III) refers to the number of Ti gram atoms substantially contained in (III).

As the organoaluminum compound (A ₂ ) to be combined with the titanium trichloride composition (III) during the polymerization of propylene, a dialkylaluminum monohalide represented by the general formula of AlR ³ R ⁴ X is preferable. In the formula, R ³ and R ⁴ are alkyl groups,
It represents a hydrocarbon group such as a cycloalkyl group, an aryl group, an alkaryl group or an alkoxy group, and X represents halogen. Specific examples include diethylaluminum monochloride, di-n-propylaluminum monochloride,
Examples thereof include di i-butyl aluminum monochloride, di n-butyl aluminum monochloride, diethyl aluminum monoiodide, diethyl aluminum monobromide and the like.

Specific examples which can be used as the aromatic carboxylic acid ester (E) which is another component constituting the catalyst include ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate,
Methyl toluate, ethyl toluate, toluic acid 2-
Ethylhexyl, methyl anisate, ethyl aniate, propyl anisate, ethyl cinnamate, methyl naphthoate,
Propyl naphthoate, butyl naphthoate, naphthoic acid 2
-Ethylhexyl, ethyl phenylacetate and the like.

The catalyst thus obtained for use in the present invention is used for the polymerization of propylene. As the polymerization method for polymerizing propylene, as described above, the polymerization of propylene is carried out in a hydrocarbon solvent such as n-hexane, n-heptane, n-octane, benzene or toluene, or slurry polymerization, or in liquefied propylene. Polymerization and gas phase polymerization can be performed.

As the polymer crystallinity capable of exerting the effect of the present invention with respect to the polypropylene obtained by the above-mentioned various polymerization modes, the isotactic pentad fraction (P) is MF.
In relation to R, the range is 1 ≧ P ≧ 0.015 log MFR + 0.955. The higher the MFR is, the higher the P tends to be, and the MFR is usually 0.05 to 200, preferably about 0.1 to 100 is practical. The polymerization temperature is usually 20 to 100 ° C, preferably 40 to 85 ° C. If the temperature is too low, the polymerization activity becomes low, which is not practical, and if the temperature is high, it becomes difficult to increase the isotacticity. Polymerization pressure is normal pressure ~ 50kg / c
It is usually carried out for 30 minutes to 15 hours at m ² G. At the time of polymerization, the addition of an appropriate amount of hydrogen for controlling the molecular weight is the same as the conventional polymerization method.

Thus, the polypropylene obtained by the method of the present invention is a high-rigidity polypropylene having remarkably high transparency, and is used for various molded articles by the known techniques such as injection molding, vacuum molding, extrusion molding and blow molding. It

[Action]

Although the detailed mechanism of the high-rigidity polypropylene obtained by the method of the present invention is unknown, the high-rigidity polypropylene production performance possessed by the catalyst comprising a predetermined amount of a combination of the catalyst components used in the present invention provides high rigidity. Show. Further, by containing a highly stereoregular saturated ring polymer in a dispersed state, the saturated ring polymer exhibits a nucleating action during melt molding, thereby promoting crystallization of polypropylene, resulting in the entire polypropylene. In addition, the transparency and crystallinity are improved, and the state of dispersion of the saturated ring polymer is extremely good as a result of the introduction method of the present invention, so that the generation of voids is extremely small.

Furthermore, since the saturated ring polymer introduced by the method of the present invention is a stereoregular high molecular weight polymer as described above, it does not bleed on the surface.

〔Example〕

Hereinafter, the present invention will be described with reference to examples. The definitions of terms used in Examples and Comparative Examples and the measuring methods are as follows.

(1) TY: Polymerization activity, polymer yield per 1 gram atom of titanium (unit: kg / gram atom) (2) MFR: Melt flow rate JIS K7210 Conditions 14 in Table 1
by. (Unit: g / 10 minutes) (3) Isotactic pentad fraction (P): Macromo
It is measured based on lecules 8 687 (1975). ¹³ C-NMR
Is the isotactic fraction in pentad units in the polypropylene molecular chain.

(4) Internal haze: The haze inside the film excluding the effect of the surface, using a press machine at a temperature of 200 ° C and a pressure of 200 kg.
A polypropylene film with a thickness of 150μ was prepared under the condition of / cm ² G, and liquid paraffin was applied to both sides of the film.
The haze was measured according to SK 7105. (Unit:%) (5) Crystallization temperature: Measured with a differential scanning calorimeter at a descending rate of 10 ° C / min. (Unit: ° C) (6) Rigidity: Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-
4'-hydroxyphenyl) propionate] methane 0.
1 part by weight and 0.1 part by weight of calcium stearate were mixed, and the mixture was granulated using an extruder having a screw diameter of 40 mm. Then, the granulated product is made into a JIS type test piece at a molten resin temperature of 230 ° C. and a mold temperature of 50 ° C. with an injection molding machine, and the test piece is left for 72 hours in a room at a humidity of 50% and a room temperature of 23 ° C. Was measured by the following method.

(A) Flexural modulus: JIS K 7203 compliant (Unit: kgf / cm ² ) (b) Tensile strength: JIS K 7113 compliant (Unit: kgf / cm ² ) (C) Rockwell hardness (R scale): JIS Compliant with K 7202 (d) Heat distortion temperature (HDT): Compliant with JIS K 7202 (Unit: ° C) (7) Void: Polypropylene is granulated in the same manner as in the previous section, and the resulting granulated product is T- Using a die-type film-forming machine, extrude at a molten resin temperature of 250 ° C, and use a cooling roll at 20 ° C for a thickness of 1 mm.
Created a sheet of. The sheet was heated with hot air at 150 ° C. for 70 seconds and stretched 7 times in the machine and transverse directions using a biaxial stretching machine to obtain a biaxially stretched film having a thickness of 20 μm. The film was observed with an optical microscope, and the number of voids having a diameter of 10 μ or more was measured. Less than 20 per 1 cm ² was indicated by ◯, 20 or more and less than 50 by Δ, and 50 or more by x.

Example 1 (1) Production of titanium trichloride composition (III) 25 parts of n-hexane (6 l), diethylaluminum monochloride (DEAC) (5.0 mol) and diisoamyl ether (12.0 mol) were added.
Mix for 1 minute at ℃ and react for 5 minutes at the same temperature to produce reaction product (I) (diisoamyl ether / DEAC molar ratio 2.4)
Got

Put 40 mol of titanium tetrachloride in a reactor purged with nitrogen and
It is heated to ℃, and the total amount of the above reaction product liquid (I) is added to
After dripping in minutes, keep at the same temperature for 60 minutes, raise to 80 ° C and react for 1 hour, cool to room temperature, remove the supernatant liquid, add 20 liters of n-hexane and decant the supernatant liquid. The operation except for was repeated 4 times to obtain a solid product (II).

The whole amount of this (II) was suspended in 30 liters of n-hexane, 400 g of diethylaluminum monochloride was added, 3.8 kg of vinylcyclohexane was added at 40 ° C., and polymerization treatment was carried out at 40 ° C. for 2 hours. After the treatment, raise the temperature to 50 ℃ and remove the supernatant.
The operation of adding 30 liters of hexane and removing the supernatant liquid by decantation was repeated 4 times to obtain a solid product (II-A) subjected to polymerization treatment.

With the total amount of this solid product suspended in 9 liters of n-hexane, 3.5 kg of titanium tetrachloride was added at room temperature for about 10 minutes and reacted at 80 ° C for 30 minutes, and then diisoamyl ether was added. 1.6 kg was added and reacted at 80 ° C. for 1 hour. After the reaction was completed, the operation of removing the supernatant was repeated 5 times and then dried under reduced pressure to obtain a titanium trichloride composition (III). The obtained titanium trichloride composition (III) had a vinylcyclohexane polymer content of 50.0% by weight and a titanium content of 12.6% by weight.

(2) Preparation of pre-activated catalyst component After replacing a stainless reactor with an inclined blade with an internal volume of 150 l with nitrogen gas, 100 l of n-hexane, 114 g of diethylaluminum monochloride, and the titanium trichloride composition obtained in (1) After adding 1.8 kg of the compound (III) at room temperature, 1.8 Nm ^{3 of} ethylene was supplied at 30 ° C. for 2 hours to cause a reaction (per 1 g of the titanium trichloride composition (III), 1.0 g of ethylene was reacted). Unreacted ethylene was removed, washed with n-hexane and then dried to obtain a preactivated catalyst component.

(3) Polymerization of Propylene n-hexane was added to the pre-activated catalyst component obtained in (2) above in a polymerization vessel with a stirrer equipped with a two-stage turbine blade having an internal volume of 200 l, and 4.0 wt% n-hexane suspension After being made into a liquid, the suspension was converted into titanium atoms at 14.5 mg atom / hr, and diethylaluminum monochloride and methyl p-toluate were used in the same pipe so that the molar ratios were 4.0 and 1.0, respectively. From another pipe n
-Hexane was continuously fed at 21 kg / hr. Furthermore,
Hydrogen was supplied so that the concentration in the gas phase of the polymerization vessel was kept at 2.9% by volume, and propylene was supplied so that the total pressure was kept at 10 kg / cm ² G, and continuous polymerization of propylene was continuously performed for 120 hours. .

During the polymerization period, the slurry retention level in the polymerization vessel was 75
The slurry was continuously withdrawn from the polymerization vessel to a flash tank having an internal volume of 50 l so as to have a volume%. Depressurized in the flash tank to remove unreacted propylene and hydrogen, while methanol was supplied at 1 kg / hr at 70 ° C.
Was contact-treated. Subsequently, after neutralization with an aqueous sodium hydroxide solution, the polymer was washed with water, separated, and dried,
A product polypropylene of MFR 1.9 was obtained at 10 kg / hr.

Comparative Example 1 (1) The same procedure as in (1) of Example 1 was repeated except that the solid product (II) was replaced with the solid product (II-A) without the polymerization treatment with vinylcyclohexane. A titanium chloride composition was obtained.

(2) In the same manner as in (2) of Example 1, except that the titanium trichloride composition (III) obtained in (1) above was used instead of the titanium trichloride composition (III), The preparation was done.

(3) In (3) of Example 1, the pre-activated catalyst component obtained in the above (2) is used as the pre-activated catalyst component, and each catalyst component is maintained so that the total pressure is maintained at 10 kg / cm ² G. Polypropylene was obtained in the same manner except that was charged into the polymerization vessel.

Examples 2 and 3 In (3) of Example 1, the hydrogen concentration in the gas phase of the polymerization vessel was changed to 4.3% by volume (Example 2) and 9.6% by volume (Example 3), and the total pressure was changed. Polypropylene was obtained in the same manner as in Example 1 except that each catalyst component was supplied to the polymerization vessel so as to maintain 10 kg / cm ² G.

Comparative Examples 2 and 3 In (3) of Comparative Example 1, the hydrogen concentration in the gas phase of the polymerization vessel was changed to 3.8% by volume (Comparative Example 2) and 10.4% by volume (Comparative Example 3), and the total pressure was changed. Polypropylene was obtained in the same manner as in Example 1 except that each catalyst component was supplied to the polymerization vessel so as to maintain 10 kg / cm ² G.

Comparative Example 4 (1) A titanium trichloride composition was obtained in the same manner as in Comparative Example 1 (1).

(2) In the reactor used in (2) of Example 1, 100 l of n-hexane, 300 g of diethylaluminum monochloride,
And 1.8 kg of the titanium trichloride composition obtained in (1) above was added at room temperature, and then 3.0 kg of vinylcyclohexane was added to 40 ° C.
At room temperature for 2 hours (1 g of titanium trichloride composition: 1.
0g reaction). After completion of the reaction, it was washed with n-hexane, filtered and dried to obtain a catalyst component preactivated with vinylcyclohexane.

(3) Polymerization of propylene was carried out in the same manner as in (3) of Example 1 except that the catalyst component pre-activated with vinylcyclohexane obtained in (2) above was used as the pre-activated catalyst component. Since the generated bulk polymer clogged the slurry withdrawing pipe, the production had to be stopped 8 hours after the initiation of the polymerization.

Comparative Example 5 (1) Titanium trichloride composition obtained in the same manner as in (1) of Comparative Example 1 when the reaction product liquid (I) was reacted with titanium tetrachloride in (1) of Comparative Example 1. Vinylcyclohexane obtained by adding 2.7 kg of vinylcyclohexane to 100 l of n-hexane at 60 ° C for 2 hours was polymerized by using 500 g of the product and 120 g of diethylaluminum monochloride as a catalyst, followed by washing with methanol and drying. Combine 1.
A titanium trichloride composition containing 50% by weight of a vinylcyclohexane polymer was obtained in the same manner except that 9 kg was ground in a vibrating mill having a capacity of 10 l at room temperature for 5 hours and then suspended in titanium tetrachloride. It was

(2) A preactivated catalyst component was obtained in the same manner as in (2) of Example 1 except that the titanium trichloride composition obtained in (1) above was used in place of the titanium trichloride composition (III). .

(3) Using the pre-activated catalyst component obtained in (2) as the pre-activated catalyst component in (3) of Example 1,
Further, polypropylene was obtained in the same manner except that each catalyst component was supplied to the polymerization vessel so that the total pressure was kept at 10 kg / cm ² G.

Comparative Example 6 4 l of n-hexane and 10 mol of titanium tetrachloride were placed in a reactor purged with nitrogen and kept at 0 ° C, and 4 l of an n-hexane solution containing 8 mol of diethylaluminum monochloride.
Was added dropwise, the temperature was raised to 40 ° C., and the reaction was continued for 1 hour. Then, after adding 3.8 kg of vinylcyclohexane, 2 at the same temperature
It was polymerized for a period of time. After the polymerization treatment, after removing the supernatant liquid, n
-Add 5 liters of hexane and remove by decantation.
The resulting solid product, which has been subjected to the polymerization treatment, is repeated n times.
-Suspended in 9 l of hexane. Subsequently, titanium tetrachloride
3.5 kg was added at room temperature and reacted at 90 ° C. for 1 hour. After completion of the reaction, it was washed with n-hexane to obtain a titanium trichloride composition. Propylene was polymerized in the same manner as in Comparative Example 1 except that the titanium trichloride composition was used to obtain polypropylene.

Comparative Example 7 A polypropylene was obtained in the same manner as in Comparative Example 1 except that the catalyst component methyl p-toluate in Comparative Example 1 (3) was not used.

Comparative Example 8 and Examples 4 and 5 In (1) of Example 1, 3-methylvinylcyclohexane was used in place of vinylcyclohexane, and the amount thereof was changed to 0.05 g, 250 g and 10 kg, respectively, to carry out the polymerization treatment. Polypropylene was obtained in the same manner as in Example 1 except that the steps were performed.

Comparative Examples 9 to 11 and Examples 6 and 7 Using 22 kg of vinylcycloheptane instead of vinylcyclohexane in (1) of Example 1 and (3) of titanium trichloride composition of methyl p-toluate. Polypropylene was obtained in the same manner as in Example 1 except that the molar ratio to the product (III) was changed as shown in the table.

Example 8 4 L of n-heptane, diethylaluminium monochloride
The reaction solution obtained by reacting 5.0 mol, 9.0 mol of diisoamyl ether and 5.0 mol of di-n-butyl ether at 18 ° C. for 30 minutes was added dropwise to 27.5 mol of titanium tetrachloride at 40 ° C. for 300 minutes. After reacting at the temperature for 1.5 hours, the temperature was raised to 65 ° C and the reaction was continued for 1 hour. The supernatant was removed and n-hexane was added.
The operation of adding 20 L and removing by decantation was repeated 6 times, and 1.8 kg of the obtained solid product (II) was added to n-hexane 40
suspended in l, and diethyl aluminum monochloride 5
Add 00g and add 11kg vinylcyclopentane at 50 ℃ 1
The reaction was carried out for a time to obtain a solid product (II-A) which had been subjected to a polymerization treatment.

After the reaction, the supernatant liquid was removed, 20 l of n-hexane was added, and the operation of removing by decantation was repeated twice. The solid product (II-A) subjected to the above polymerization treatment was suspended in 7 l of n-hexane. Muddy, 1.8 kg titanium tetrachloride, n-butyl ether 1.8
kg was added and reacted at 60 ° C. for 3 hours. After completion of the reaction, the supernatant was removed by decantation, 20 l of n-hexane was added, the mixture was stirred for 5 minutes and allowed to stand, and the operation of removing the supernatant was repeated 3 times, followed by drying under reduced pressure and trichloride. Titanium composition (II
I) was obtained, and propylene was polymerized in the same manner as in (2) and (3) of Example 1 except that the titanium trichloride composition (III) was used.

Comparative Example 12 A titanium trichloride composition was obtained in the same manner as in Example 8 except that the solid product (II) was used as the solid product (II-A) equivalent without the polymerization treatment with vinylcyclopentane. , Propylene was polymerized.

Example 9 (1) Titanium tetrachloride (27.0 mol) was added to n-hexane (12 l) and the mixture was cooled to 1 ° C., and then n-hexane (12.5 l) containing diethyl aluminum monochloride (27.0 mol) was added dropwise at 1 ° C. over 4 hours. did. After completion of the dropping, the reaction was carried out at the same temperature for 15 minutes, then the temperature was raised to 65 ° C. over 1 hour, and the reaction was further performed at the same temperature for 1 hour.

Next, the supernatant liquid was removed, 10 l of n-hexane was added, and the operation of removing by decantation was repeated 5 times, and 1.8 kg of 5.7 kg of the obtained solid product (II) was suspended in 50 l of n-hexane. , 350g of diethylaluminum monochloride was added, and cyclopentamethylene vinylsilane 5.2k was added at 40 ℃.
After further adding g, polymerization treatment was carried out at 40 ° C. for 2 hours.

After the polymerization treatment, the supernatant was removed, 30 l of n-hexane was added, and the operation of removing by decantation was repeated twice.
The whole amount of the obtained solid product (II-A) subjected to the polymerization treatment was suspended in n-hexane 11, to which 1.2 l of diisoamyl ether and 0.4 l of ethyl benzoate were added. This suspension was stirred at 35 ° C. for 1 hour and then washed 5 times with 3 l of n-hexane to obtain a treated solid. The treated solid obtained is titanium tetrachloride.
40% by volume and 10% by volume of silicon tetrachloride were suspended in 6 l of n-hexane solution.

This suspension was heated to 65 ° C. and reacted at the same temperature for 2 hours. After the reaction was completed, 20 l of n-hexane was used once and 3
The solid thus obtained was washed and then dried under reduced pressure to obtain a titanium trichloride composition (III).

(2) Preparation of pre-activated catalyst component In (2) of Example 1, the titanium trichloride composition (II
Titanium trichloride composition (III) obtained in (1) above as I)
1.8 kg was used, and propylene 1.3 was used instead of ethylene.
In the same manner as in (2) of Example 1 except that Kg was used,
A preactivated catalyst component was obtained.

(3) Polymerization of Propylene In (3) of Example 1, the pre-activated catalyst component obtained in the above (2) was used as the pre-activated catalyst component, and a titanium trichloride composition of diethyl aluminum monochloride (III Polymerization of propylene was conducted in the same manner as in (3) of Example 1 except that the molar ratio of the propylene was 3.0 and the catalyst components were fed so that the total pressure was kept at 10 kg / cm ² G. Got

Comparative Example 13 A polypropylene trichloride was obtained in the same manner as in Example 9 except that the polymerization treatment with cyclopentamethylene vinylsilane was omitted in (1) of Example 9 to obtain a titanium trichloride composition.

Example 10 (1) The reaction product solution (I) was obtained in the same manner as in (1) of Example 1 except that 4.0 mol of di-n-butylaluminum monochloride was used instead of diethylaluminum nomochloride.
A titanium trichloride composition (III) was obtained in the same manner except that it was added dropwise to titanium tetrachloride at 45 ° C. and that 9.5 kg of cyclohexyldimethylvinylsilane was used instead of vinylcyclohexane.

(2) The procedure of (2) of Example 1 was repeated except that 1.8 kg of the titanium trichloride composition (III) obtained in (1) above was used as the titanium trichloride composition (III). In the same manner as in ()), a preactivated catalyst component was obtained.

(3) In (3) of Example 1, the preactivation catalyst component obtained in the above (2) is used as the preactivation catalyst component, ethyl p-anisate is used as the aromatic carboxylic acid ester, and the organoaluminum compound is used. Using an equimolar mixture of diethylaluminium iodide and n-propylaluminum monochloride, setting the molar ratio of the organoaluminum compound to the titanium trichloride composition (III) to 5.0, and making the total pressure 10 kg / cm ² Polypropylene was obtained in the same manner except that each catalyst component was supplied so that G was maintained.

Comparative Example 14 A polypropylene was obtained in the same manner as in Example 10, except that the polymerization treatment with cyclohexyldimethylvinylsilane was omitted in Example 10 (1) to obtain a titanium trichloride composition.

The main points of the catalyst systems, polymerization results and evaluation results of Examples 1 to 10 and Comparative Examples 1 to 14 described above are shown in the table on the next page.

[Effects of the Invention] The main effects of the present invention are that the occurrence of voids is extremely small, without causing problems in production such as formation of a lump polymer.
That is, a highly rigid polypropylene having extremely high transparency and rigidity can be obtained.

As is clear from the above-mentioned examples, the internal haze of the film produced by using the polypropylene obtained by the method of the present invention is the titanium trichloride composition obtained without the polymerization treatment with the saturated ring monomer. Compared with the case of using the polypropylene obtained by using, it is about 1/7 to 2/7, and has extremely high transparency. (Examples 1-10, Comparative Examples 1-
Also, the crystallization temperature is increased by about 8 ° C to 10 ° C as compared with the polypropylene obtained by the method of the prior invention, and the crystallinity is remarkably improved, resulting in bending elasticity. The rate is also improving. (See Examples 1 to 10 and Comparative Examples 1 to 3 and 12 to 14) Furthermore, it is clear that the number of voids generated is significantly less than that of polypropylene introduced with a saturated ring polymer by a method other than the present invention. Is. (Examples 1 to 10,
(See Comparative Examples 4 and 5)

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram (flow sheet) for explaining the method of the present invention.

Claims (5)

[Claims] 1. A solid product obtained by reacting titanium tetrachloride with an organoaluminum compound (A ₁ ) or a reaction product (I) of an organoaluminum compound (A ₁ ) and an electron donor (B ₁ ). Polymerizing (II) with a saturated ring hydrocarbon monomer having 5 to 20 carbon atoms which may contain silicon and has a saturated cyclic structure of a hydrocarbon which may contain silicon and a c = c bond. A titanium trichloride composition (III) obtained by a method of treating and further reacting an electron donor (B ₂ ) with a halide of an element of Group III to VI of the periodic table, wherein the saturated ring Titanium trichloride composition containing 0.01 to 99% by weight of a polymer of hydrocarbon monomer (III)
And an organoaluminum compound (A ₂ ) and an aromatic carboxylic acid ester (E) are combined, and the molar ratio of the aromatic carboxylic acid ester (E) and the titanium trichloride composition (III) is (E) / (II
I) = 0.1 to 10.0, and the organoaluminum compound (A ₂ )
And the titanium trichloride composition (III) in a molar ratio of (A ₂ ) / (I
II) A method for producing high-rigidity polypropylene, which comprises polymerizing propylene using a catalyst of 0.1 to 200. 2. An organoaluminum compound (A ₁ ) having a general formula of A ₁ R ¹ _p R ² _{p ′} X _{3- (p + p ′)} (wherein R ¹ and R ² are an alkyl group, a cycloalkyl group or an aryl group). A hydrocarbon group or an alkoxy group such as, X represents halogen, and
p and p'represent an arbitrary number of 0 <p + p'≤3. The manufacturing method of Claim 1 which uses the organoaluminum compound represented by these. 3. The process according to claim 1, wherein a dialkylaluminum monohalide is used as the organoaluminum compound (A ₂ ). 4. A patent using a catalyst component preliminarily activated with a small amount of α-olefin, instead of the titanium trichloride composition (III), in which the titanium trichloride composition (III) is combined with an organoaluminum compound. The manufacturing method according to claim 1. 5. The method according to claim 1, wherein the relationship between the isotactic pentad fraction (P) of polypropylene and MFR is within the range of 1.00 ≧ P ≧ 0.015 1og MFR + 0.955. .