JPH07309913A - Polypropylene - Google Patents

Abstract

PURPOSE:To obtain a polypropylene which has low content of an atactic component in spite of the relatively low stereoregularity, scarcely contains a residual catalyst and is suitable for film. CONSTITUTION:A propylene homopolymer which has a melt flow rate of 0.1-10g/10min, an isotactic pentad fraction of 0.85 to 0.94, a boiling heptane insoluble of at least 97.5wt.%, and concentrations of titanium atoms and chlorine atoms respectively remaining in the polymer of at most 3ppm and at most 30ppm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a relatively low stereoregularity but has a small amount of atactic component.
In addition, the present invention relates to a polypropylene suitable for film forming in which the amount of catalyst remaining in the polymer is extremely small.

[0002]

Polypropylene is generally excellent in rigidity, heat resistance, chemical resistance and moldability, and is widely used for extrusion molding, blow molding, injection molding and the like of sheets and films. However, in each molding field, there still remains a problem that the performance cannot be said to be sufficient. In particular, in the field of extrusion molding of films, sheets, etc., it is the actual situation that polypropylene having an excellent balance of processability, physical properties of molded articles and quality is not yet achieved. In order to improve the processability of extrusion molding, it is known that it is effective to reduce the stereoregularity of polypropylene and to reduce the processing energy (JP-A-57-47371, JP-A-3-1957571). Issue).
However, as its adverse effect, there is a problem that a large amount of atactic component is produced as a by-product, the heat shrinkability of the obtained sheet or film becomes extremely large, and the quality is impaired. As described above, conventionally, it has been difficult to reduce stereoregularity and reduce the amount of atactic component in order to improve processability.

It is well known that polypropylene is produced by using a catalyst composed of a titanium halide compound and an organoaluminum compound. If these remain in the produced polypropylene, the color tone of the molded product becomes yellow, which causes a problem of poor appearance. In addition, when chlorine atoms remain in polypropylene, metal soap such as calcium stearate is generally blended as a processing aid or chlorine scavenger, which reacts with chlorine atoms to release fatty acids such as stearic acid. To do. When such polypropylene is used for film forming, there remains a problem that the film quality is adversely affected due to roll stains and eye bleeding during forming.

[0004]

As described above, it has a relatively low stereoregularity for improving processability, has a small amount of atactic component for improving the physical properties of a molded product, and has a roll at the time of molding. There has been a demand for polypropylene that has a small amount of catalyst residue in order to prevent stains and eye blemishes.

[0005]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that polypropylene having a relatively low stereoregularity, a low atactic component content, and a low catalyst residue. It was found that the above problems were solved, and the present invention was completed.

That is, the present invention has a melt flow rate of 0.1 to 10 g / 10 min, an isotactic pentad fraction of 0.85 to 0.94, and a boiling heptane insoluble content of 97.5% by weight or more. In addition, the propylene homopolymer is characterized in that the concentration of titanium atoms remaining in the polymer is 3 ppm or less and the concentration of chlorine atoms is 30 ppm or less, and the present invention has a melt flow rate of 0. 1 to 10 g / 10 min, isotactic pentad fraction is 0.85 to 0.94, boiling heptane insoluble matter is 97.5% by weight or more, and the concentration of titanium atoms remaining in the polymer is 3 ppm or less. , And the concentration of chlorine atoms is 30 ppm or less, the monomer unit based on propylene is 95% by weight or more, and the monomer unit based on α-olefin other than propylene is Propylene -α or less by weight%
-It also provides an olefin random copolymer.

In the present specification, the above-mentioned propylene homopolymer and propylene-α-olefin random copolymer are simply referred to as polypropylene. The polypropylene of the present invention is essentially a homopolymer of propylene, but in a range that does not impair the effects of the present invention, for example,
5% by weight or less may contain an α-olefin other than propylene as a copolymerization component. Further, in the prepolymerization described later, when an α-olefin other than propylene or a vinylcycloalkane is used, the resulting polymer contains a small amount of the α-olefin or vinylcycloalkane. In this case, the content of α-olefin or vinylcycloalkane varies depending on the prepolymerization ratio, but is usually 0.5% by weight or less. Examples of α-olefins other than propylene include ethylene, 1-butene, 1-hexene, 3-methyl-1-butene, and 4-methyl-1-pentene.

The melt flow rate of the polypropylene of the present invention is 0.1 to 10 g / 10 min. 0.1 g
If it is less than / 10 min, the melt fluidity is poor, while 10 g
If it exceeds / 10 min, the melt tension is poor, and any of them is not preferable because the workability is deteriorated. Considering workability, the preferable range is 0.3 to 8 g / 10 min, and more preferably 0.5 to 6 g / 10 min. The weight average molecular weight of the polypropylene of the present invention is approximately proportional to the above-mentioned melt flow rate, and is a value measured by GPC (gel permeation chromatography) method using orthodichlorobenzene as a solvent, which is 200,000 to 100.
In many cases. Considering workability, the preferable range is 25
It is 10,000 to 700,000, and more preferably 300,000 to 600,000.

The polypropylene of the present invention has an isotactic pentad fraction in the range of 0.85 to 0.94. The isotactic pentad fraction referred to in the present invention refers to A. Macromol by Zambelli et al.
ecules, 6, 925 (1973), that is, the fraction in which 5 propylene units are continuously bonded to meso as measured by ¹³ C-NMR. The measured value of the isotactic pentad fraction in the present invention is a value for a polypropylene itself obtained by polymerization, which has not been subjected to extraction, fractionation or washing with a solvent.

Isotactic pentad fraction 0.8
When it is less than 5, the workability is good, but the mechanical properties of the obtained molded product, such as rigidity and heat resistance, are deteriorated, which is not preferable. On the other hand, when it exceeds 0.94, not only the mechanical load at the time of processing increases, but also the phenomenon of tearing frequently occurs during film formation, which makes stable film formation difficult, which is not preferable. The preferred range of the isotactic pentad fraction is 0.86 to 0.93, more preferably 0.8.
It is 8 to 0.93.

The polypropylene of the present invention is characterized in that the amount of atactic component is extremely low in spite of having the above-mentioned relatively low stereoregularity. The value of the boiling heptane-insoluble matter of the polypropylene of the present invention is 97.5% or more. When it is less than 97.5%, the heat shrinkability when formed into a film becomes extremely large, which is not preferable. A suitable range is 98.0% or more. The above values are the values for the polypropylene itself obtained by the polymerization, which has not been subjected to any extraction, fractionation or washing with a solvent.

The polypropylene of the present invention is characterized in that there is little catalyst residue remaining, there is no roll stain due to liberation of fatty acids when a metal soap is used as a lubricant and a chlorine scavenger, and the color tone is excellent. In the polypropylene of the present invention, the residual titanium atom content is 3 ppm or less, preferably 2 ppm or less. On the other hand, the concentration of chlorine atoms is 3
It is 0 ppm or less, preferably 20 ppm or less. If the concentration of titanium atoms exceeds 3 ppm, the color tone of the molded product becomes particularly yellow, which is not preferable. Further, if the concentration of chlorine atoms exceeds 30 ppm, fatty acids are liberated from the added metal soap and cause roll contamination, which is not preferable. The concentration of these atoms can be measured by a fluorescent X-ray method or an atomic absorption method. These values for the polypropylene of the present invention are polypropylene itself obtained by polymerization, extraction with a solvent,
This is the value for a polymer that has not been subjected to fractionation or washing.

Further, the value of the molecular weight distribution represented by the ratio of the weight average molecular weight and the number average molecular weight of the polypropylene of the present invention is not particularly limited, but the melt tension is increased,
In order to further improve the workability, it is preferably 6.0 or more, more preferably 6.5 or more, and particularly preferably 7.0 or more.

The method for producing the polypropylene of the present invention is not particularly limited, but it can be produced, for example, by the following method.

[A] Titanium compound [B] General formula R ₃ Al [I] (wherein R is a saturated hydrocarbon group having 1 to 10 carbon atoms) [C] General formula R ¹ R ² Si (OR ³ ) ₂ [II] (wherein R ¹ , R ² and R ³ are the same or different hydrocarbon groups having 1 to 20 carbon atoms, and R ¹ and R ²
At least one of them has an atom directly connected to the silicon atom,
It is a chain hydrocarbon group which is a tertiary carbon or a cyclic hydrocarbon group which is a secondary carbon. In the presence of a Lewis acid compound having at least one halogen atom, [alpha] -olefin or vinylcycloalkane is first prepolymerized in an amount of 0.1 to 100 g per 1 g of the titanium compound, and then, In the presence of the obtained titanium-containing polyolefin and [B] organoaluminum compound, homopolymerization of propylene or random copolymerization of propylene with other α-olefins is carried out.

As the titanium compound [A] used in the prepolymerization method of the present invention, compounds known to be used for the polymerization of α-olefins can be adopted without any limitation. In particular, a titanium compound containing titanium, magnesium and halogen as components and having high catalytic activity is particularly preferable. Such a titanium compound having a high catalytic activity is one in which various halogen compounds, particularly titanium tetrachloride, are supported on various magnesium compounds. As a method for producing this catalyst, a known method can be adopted without any limitation. For example, a method of co-milling titanium tetrachloride with a magnesium compound such as magnesium chloride, a method of co-milling a titanium halide and a magnesium compound in the presence of an electron donor such as alcohol, ether, ester, ketone or aldehyde, or , A method of bringing a titanium halide, a magnesium compound and an electron donor into contact with each other in a solvent. A method for producing such a titanium compound is described, for example, in JP-A-56-155206.
56-136806, 57-34103, 58-
8706, 58-83006, 58-13870.
8, the same 58-183709, the same 59-206408, the same 59-21931, the same 60-81208, the same 60-8.
1209, 60-186508 and 60-19270
8, the same 61-211309, the same 61-271304, the same 62-15209, the same 62-11706, the same 62-72.
702, 62-104810 and the like.

Next, as the organoaluminum compound [B], the compound represented by the general formula [I] can be used without any limitation. In the general formula [I], R is a saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the saturated hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, t-
Butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group,
Examples thereof include chain alkyl groups such as decyl group, cyclopentyl group, cyclohexyl group and cyclic alkyl groups.

Specific examples of the organoaluminum compound [B] that can be preferably used in the present invention include, for example:
Trimethyl aluminum, triethyl aluminum, tri-n propyl aluminum, tri-n butyl aluminum, tri-i butyl aluminum, tri-n hexyl aluminum, tri-n octyl aluminum, tri-
Trialkylaluminums such as n-decylaluminum can be used. Of these, triethylaluminum is most preferable.

The amount of the organoaluminum compound used in the prepolymerization is not particularly limited, but in general, the Al / Ti (molar ratio) is preferably 1 to 100 with respect to Ti atoms in the titanium compound, Further, it is preferably 3 to 10.

Further, as the organosilicon compound [C], the compound represented by the general formula [II] can be used without any limitation. In the general formula, the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ , R ² and R ³ is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group. , Pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, and cyclopentyl group, alkyl group-substituted cyclopentyl group, cyclohexyl group, alkyl group-substituted cyclohexyl group, t-
Examples thereof include a butyl group and a t-amyl group.

In the above general formula [II], at least one of R ¹ and R ² is a chain hydrocarbon group in which the atom directly bonded to the silicon atom is a tertiary carbon, or is a secondary carbon. It is a cyclic hydrocarbon group. Here, examples of the chain hydrocarbon group in which the atom directly bonded to the silicon atom is a tertiary carbon include a t-butyl group and a t-amyl group. Further, as the cyclic hydrocarbon group in which the atom directly bonded to the silicon atom is secondary carbon, a cyclopentyl group, a 2-methylcyclopentyl group, a 3-methylcyclopentyl group, a 2-ethylcyclopentyl group, a 2-n-butylcyclopentyl group, 2,3-
Dimethylcyclopentyl group, 2,4-dimethylcyclopentyl group, 2,5-dimethylcyclopentyl group, 2,3
-Diethylcyclopentyl group, 2,3,4-trimethylcyclopentyl group, 2,3,5-trimethylcyclopentyl group, 2,3,4-triethylcyclopentyl group, tetramethylcyclopentyl group, tetraethylcyclopentyl group, cyclohexyl group, 2-methyl Cyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, 2-ethylcyclohexyl group, 2,3-dimethylcyclohexyl group, 2,4-dimethylcyclohexyl group, 2,5-dimethylcyclohexyl group, 2,6-dimethyl Cyclohexyl group, 2,3-diethylcyclohexyl group, 2,3,4-trimethylcyclohexyl group,
2,3,5-trimethylcyclohexyl group, 2,3,6
-Trimethylcyclohexyl group, 2,4,5-trimethylcyclohexyl group, 2,4,6-trimethylcyclohexyl group, 2,3,4-triethylcyclohexyl group,
2,3,4,5-tetramethylcyclohexyl group, 2,
3,4,6-tetramethylcyclohexyl group, 2,3
5,6-tetramethylcyclohexyl group, 2,3,4
Examples include 5-tetraethylcyclohexyl group, pentamethylcyclohexyl group, pentaethylcyclohexyl group and the like.

Examples of the organosilicon compound preferably used in the present invention are as follows. For example, the t-
Butyldimethoxysilane, di-t-amyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, di (2-methylcyclopentyl) dimethoxysilane, di (3-methylcyclopentyl) dimethoxysilane, di (2-ethylcyclopentyl) dimethoxysilane, Di (2,3-dimethylcyclopentyl) dimethoxysilane, di (2,4-dimethylcyclopentyl) dimethoxysilane, di (2,5-dimethylcyclopentyl) dimethoxysilane, di (2,3-diethylcyclopentyl) dimethoxysilane, di ( 2, 3,
4-trimethylcyclopentyl) dimethoxysilane, di (2,3,5-trimethylcyclopentyl) dimethoxysilane, di (2,3,4-triethylcyclopentyl)
Dimethoxysilane, di (tetramethylcyclopentyl)
Dimethoxysilane, di (tetraethylcyclopentyl)
Dimethoxysilane, di (2-methylcyclohexyl) dimethoxysilane, di (3-methylcyclohexyl) dimethoxysilane, di (4-methylcyclohexyl) dimethoxysilane, di (2-ethylcyclohexyl) dimethoxysilane, di (2,3-dimethyl) Cyclohexyl) dimethoxysilane, di (2,4-dimethylcyclohexyl)
Dimethoxysilane, di (2,5-dimethylcyclohexyl) dimethoxysilane, di (2,6-dimethylcyclohexyl) dimethoxysilane, di (2,3-diethylcyclohexyl) dimethoxysilane, di (2,3,4-trimethylcyclohexyl) Dimethoxysilane, di (2,
3,5-trimethylcyclohexyl) dimethoxysilane, di (2,3,6-trimethylcyclohexyl) dimethoxysilane, di (2,4,5-trimethylcyclohexyl) dimethoxysilane, di (2,4,6-trimethylcyclohexyl) dimethoxy Silane, di (2,3,4-
Triethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetramethylcyclohexyl) dimethoxysilane, di (2,3,5,6-)
Tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetraethylcyclohexyl) dimethoxysilane, di (pentamethylcyclohexyl) dimethoxysilane, di (pentaethylcyclohexyl) dimethoxysilane, t-butylmethyldimethoxysilane, t
-Butylethyldimethoxysilane, t-amylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylisobutyldimethoxysilane and the like can be mentioned.

The amount of the organosilicon compound used in the prepolymerization is not particularly limited, but it is generally 0.1 in terms of Si / Ti (molar ratio) with respect to Ti atoms in the titanium compound.
It is preferably -100, and more preferably 0.5-10.

As the component [D] used in the prepolymerization of the present invention, a known compound can be used without any limitation as long as it is a Lewis acid compound having at least one halogen atom. Specific examples of the component [D] that can be preferably used in the present invention include the following compounds. For example, aluminum trichloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, diethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, diisobutyl aluminum chloride, di n-
Propyl aluminum chloride, ethyl aluminum dibromide, ethyl aluminum diiodide, isobutyl aluminum dichloride, isobutyl aluminum dibromide, isobutylaluminium diiodide and other halogen atom-containing aluminum compounds, titanium tetrachloride and other halogen atom-containing titanium compounds, Examples thereof include halogen atom-containing tin compounds such as tin tetrachloride, and halogen atom-containing zinc compounds such as zinc chloride.

Of these Lewis acid compounds, the following formula [III] AlR ⁴ _n X _3-n [III] (wherein R ⁴ is a saturated hydrocarbon group having 1 to 10 carbon atoms, X is a halogen atom) And n is a number of 0 to 2.5.) The halogen atom-containing aluminum compound represented by the formula (3) gives polypropylene at a high polymerization ratio, and the polypropylene particles obtained by the polymerization have a high bulk density. Since it is easy to handle, it can be preferably used in the present invention. In the above formula [III], as the saturated hydrocarbon group having 1 to 10 carbon atoms, the groups described for the organoaluminum compound [B] can be directly used. As the halogen atom represented by X, chlorine, bromine, and iodine atoms can be used, but in general, chlorine atom is preferable.

The amount of the Lewis acid compound used in the prepolymerization is not particularly limited, but generally, the molar ratio to the Ti atom in the titanium compound is preferably 0.1 to 100, and It is preferably 0.5 to 10.

In the present invention, in addition to the above titanium compound [A], organoaluminum compound [B], organosilicon compound [C], and Lewis acid compound [D] having at least one halogen atom, Formula [IV] R'-I [IV] (wherein R'is an iodine atom or a hydrocarbon group)
It is preferable to use the iodine compound [E] represented by the above because the amount of atactic component of the obtained polymer is further reduced. In the above general formula [IV], R ′ is an alkyl group,
It is a hydrocarbon group such as an alkenyl group, an alkynyl group or an aryl group. Specific examples of the iodine compound that can be preferably used in the present invention include iodine, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, iodobenzene, p-toluene iodide and the like. Of these, methyl iodide and ethyl iodide are preferable.

The amount of the iodine compound used in the prepolymerization is not particularly limited, but in general, I / Ti (molar ratio) is preferably 0.1 to 100 with respect to Ti atom in the titanium compound, and further 0. It is preferably from 0.5 to 50.

The above-mentioned components used in the prepolymerization may be added one after another or may be mixed together. The order of addition in the case of sequential addition is not particularly limited.

In the prepolymerization, α-olefin or vinylcycloalkane is polymerized. As the α-olefin, a linear or branched one can be used. The polymerization amount of α-olefin or vinylcycloalkane is 0.1 to 100 g, preferably 1 to 100 g, per 1 g of titanium compound, and industrially 2 to 50 g.
Is preferred. As the α-olefin used in the prepolymerization, ethylene as a linear α-olefin,
Propylene, 1-butene, 1-hexene, 1-octene and the like can be mentioned, and as the branched α-olefin, 3-methyl-1-butene, 3-methyl-1-pentene, 4,4-dimethyl- 1-pentene, 3-ethyl-1
-Pentene, 4-methyl-1-pentene, 4-methyl-
1-hexene and the like can be mentioned. Examples of vinyl cycloalkanes include vinyl cyclohexane, vinyl cyclopentane, vinyl cyclobutane, and 3-methyl vinyl cyclohexane. Further, it is possible to use two or more kinds of the above α-olefins simultaneously, and it is also possible to carry out the prepolymerization stepwise and use different α-olefins in each step. Considering the improvement of the image clarity of the molded product, it is preferable to use a branched α-olefin or a vinylcycloalkane, and further to use 90 mol% or more of a specific kind of α-olefin further improves the image clarity. Preferred for. It is also possible to make hydrogen coexist by prepolymerization.

For the prepolymerization, it is usually preferable to apply slurry polymerization, and as the solvent, a saturated aliphatic hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene is used alone, or a mixed solvent thereof is used. Can be used. The prepolymerization temperature is generally −20 to 100 ° C., particularly preferably 0 to 60 ° C.,
When the prepolymerization is carried out in multiple steps, it may be carried out under different temperature conditions in each step. The prepolymerization time may be appropriately determined according to the prepolymerization temperature and the amount of polymerization in the prepolymerization, and the pressure in the prepolymerization is not limited, but in the case of slurry polymerization, it is generally from atmospheric pressure to 5 kg / cm ^2. It is a degree. The prepolymerization may be carried out batchwise, semi-batchly or continuously. At the end of the prepolymerization, it is preferable to wash saturated aliphatic hydrocarbons or aromatic hydrocarbons such as hexane, heptane, cyclohexane, benzene, and toluene alone or with a mixed solvent, and the washing frequency is usually 5 to 6 times. Is preferred.

After the preliminary polymerization of the present invention, the main polymerization is carried out in the presence of the titanium-containing polyolefin obtained by the preliminary polymerization and the organoaluminum compound [B]. In the main polymerization,
Homopolymerization of propylene or propylene and other α
A copolymerization with olefins is carried out. The polymerization conditions in the main polymerization of the present invention are not particularly limited as long as the effects of the present invention are observed, and known methods can be adopted. Generally, the following conditions are preferable.

As the organoaluminum compound [B] used in the main polymerization, the compounds described in the above prepolymerization can be used as they are. Of these, triethylaluminum is most preferable. The amount of the organoaluminum compound used is not particularly limited, but in general, it is preferable that the Al / Ti (molar ratio) is 10 to 1000, and further 20 to 20 with respect to the Ti atom in the titanium-containing polyolefin obtained by the preliminary polymerization. It is preferably 500.

Further, for controlling the stereoregularity of the polypropylene of the present invention, ethers, amines, amides, sulfur-containing compounds,
An electron donor such as a nitrile, a carboxylic acid, an acid amide, an acid anhydride, an acid ester or an alkoxy silicon compound can coexist. Among them, alkoxy silicon compounds are
It is preferable because the amount of atactic component produced in the obtained polypropylene is reduced. Examples of the alkoxy silicon compound include the following general formula (V) or general formula (VI) R ⁵ _J —Si— (OC ₂ H ₅ ) _4-J (V) (However, R ⁵ , R ⁶ and R ⁷ are the same or different hydrocarbon groups, and J and K are 0 or 1.)
It is preferable to use the alkoxysilicon compound represented by the formula (2) because the amount of atactic component of the polypropylene obtained can be reduced and the stereoregularity can be relatively low.

The hydrocarbon group represented by R ⁵ , R ⁶ and R ⁷ in the general formulas (V) and (VI) is a chain, branched or cyclic aliphatic hydrocarbon group or aromatic hydrocarbon group. A hydrogen group can be mentioned, and the number of carbon atoms is not particularly limited.
Examples of suitable hydrocarbon groups in the present invention include methyl group, ethyl group, n-propyl group, i-propyl group and n-
A butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a pentyl group, a hexyl group, an allyl group and the like having 1 to 1 carbon atoms.
6 alkyl group; vinyl group, propenyl group, alkenyl group having 2 to 6 carbon atoms such as allyl group, ethynyl group, alkynyl group having 2 to 6 carbon atoms such as propynyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, etc. Carbon number of 5
A cycloalkyl group having 7 to 7 carbon atoms; an aryl group having 6 to 12 carbon atoms such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. In the above formula, J and K are 0 or 1.
Is.

Examples of the alkoxy silicon compound represented by the general formula (V) which is preferably used in the present invention include ethyl silicate, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane and pentyl. Triethoxysilane,
Isopropyltriethoxysilane, 1-propenyltriethoxysilane, isopropenyltriethoxysilane,
Examples thereof include ethynyltriethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, and allyltriethoxysilane.

Examples of the alkoxy silicon compound represented by the general formula (VI) include dimethyldimethoxysilane, diethyldimethoxysilane, dipropyldimethoxysilane, divinyldimethoxysilane, diallyldimethoxysilane, di-1-propenyldimethoxysilane, di- Ethynyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, tertiary butylethyldimethoxysilane, ethylmethyldimethoxysilane, propylmethyldimethoxysilane, cyclohexyltrimethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, vinyl Examples thereof include trimethoxysilane and allyltrimethoxysilane.

The amount of the alkoxysilicon compound represented by the general formulas (V) and (VI) used in the main polymerization is not particularly limited, but generally Ti as a solid titanium catalyst component is used.
Si / Ti (molar ratio) 0.1 to 500 for each atom
Is preferable, and further preferably 1 to 100.

Further, it is preferable to use an alkoxysilicon compound represented by the general formula (V) or the general formula (VI) in combination, because the molecular weight distribution of the obtained polypropylene can be broadened. V): (V
The molar ratio of I) is preferably 1: 5 to 1:25, more preferably 1:10 to 1:20. In this case, the addition order of each component is not particularly limited, and the alkoxysilicon compound represented by the general formula (V) and the general formula (V
The alkoxysilicon compounds represented by I) may be mixed and fed simultaneously or separately. Further, these may be supplied after being contacted with or mixed with the organoaluminum compound in advance.

The polymerization temperature is 20 to 200 ° C., preferably 5
The temperature is 0 to 150 ° C., and hydrogen can be coexistent as a molecular weight regulator. Further, the polymerization can be applied to slurry polymerization, solventless polymerization, and gas phase polymerization, and may be a batch type, a semi-batch type, or a continuous type. Further, the polymerization is performed in two or more stages under different conditions. You can also

The polypropylene thus obtained is preferably formed into a film in order to fully exert its advantages. The film may be unstretched or uniaxially or biaxially stretched. Specifically, polypropylene is melted and kneaded with an extruder, and the melted polypropylene is cooled and solidified into a sheet on a cooling roll with a T-type die,
An unstretched film can be obtained. Further, the obtained unstretched film is heated by a longitudinal stretching machine and then stretched 2 to 10 times to obtain a uniaxially stretched film. Furthermore, after continuously heating with a transverse stretching machine,
A biaxially stretched film can be obtained by stretching -15 times. In the case of a biaxially stretched film, it may be relaxed by 5 to 15% at a temperature slightly higher than the stretching temperature after stretching.

[0042]

EFFECTS OF THE INVENTION The polypropylene of the present invention has a relatively low stereoregularity, but has a small atactic component and a small amount of catalyst residue, so that it has excellent processability, particularly excellent film-forming property, and It is possible to obtain polypropylene having an excellent heat shrinkage when used as a molded product. Therefore, the polypropylene obtained by the present invention can be suitably used as various stretched films, non-stretched films and sheet materials.

[0043]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The measuring method used in the following examples will be described.

(1) Melt flow rate (hereinafter referred to as MFR
Abbreviated) According to ASTM D-790.

(2) Isotactic pentad fraction A. Zambilli et al., Macromolec
ules, 6, 925 (1973), that is, ¹³ C-NMR was used to determine the fraction in which 5 consecutive polymer molecular chains were bound to meso. The measurement is J
Using EOL and GSX-270, the pulse width was 90 degrees, the pulse interval was 15 seconds, and the total was 10,000 times. Peak attributions are Macromolecules, 8, 697.
(1975).

(3) Boiling Heptane Insoluble Content It was determined from the insoluble content when about 1 g of the polymer was extracted in boiling heptane for 6 hours with a Soxhlet extractor.

(4) Measurement of residual titanium concentration and chlorine concentration in polymer Approximately 10 g of polymer was press-molded at 230 ° C. to prepare a disk-shaped sheet, and then a fully automatic X-ray fluorescence analyzer system manufactured by Rigaku Denki KK The measurement was performed using 3080.

(5) Weight average molecular weight, molecular weight distribution Weight average molecular weight (Mw), and weight average molecular weight (M
The ratio between w) and the number average molecular weight (Mn) was measured by the GPC (gel permeation chromatography) method.
The measurement was carried out with a Waters GPC-150 o-
Dichlorobenzene was used as a solvent at 135 ° C.

(6) Melt tension A melt tension measuring device manufactured by Toyo Seiki Seisaku-sho, Ltd. was used.
Diameter 2.095mm in the cylinder kept at 230 ℃
The orifice, the polymer sample 6 g, and the piston were inserted, and after holding for 6 minutes, the piston was pushed down at a speed of 10 mm / min, and the extruded polymer passed through a load detector and was wound at a speed of 25 m / min. The load value at this time was defined as the melt tension.

(7) Bulk Specific Gravity Based on JIS K6721.

(8) Evaluation of Film Formability of Biaxially Stretched Film Calcium stearate was added to the polypropylene obtained.
1 wt% was compounded and extruded at 280 ° C. by an extruder equipped with a T-die, and immediately solidified by a cooling roll at 40 ° C. to obtain an unstretched sheet having a thickness of 2.0 mm. Then
The obtained unstretched sheet was stretched 5 times in the machine direction at a stretching temperature of 150 ° C. by a tenter type sequential biaxial stretching device, and subsequently stretched 10 times in the transverse direction in a tenter at a furnace temperature of 165 ° C. A biaxially stretched film was formed. Film formation speed is 4
A film forming test for 30 minutes was performed 5 times at 5 m / min. The number of breaks at this time was measured, and the roll stain was observed to evaluate the film-forming property.

(9) Heat Shrinkage of Biaxially Stretched Film According to JIS C 2318. (10) Image Value of Biaxially Stretched Film 48 hours after the formation of a biaxially stretched film having a thickness of 40 μm, an optical comb 0.12 was used with an image value measuring machine manufactured by Suga Test Instruments Co.
5 mm was used, and the comb value was made parallel to the vertical axis stretching direction, and the mapping value was measured.

Example 1 [Preparation of Titanium Compound] The titanium component was prepared according to the method of Example 1 in JP-A-58-83006. That is, 0.95 g of anhydrous magnesium chloride (10 mm
ol), decane 10 ml, and 2-ethylhexyl alcohol 4.7 ml (30 mmol) were heated and stirred at 125 ° C. for 2 hours, and 0.55 g of phthalic anhydride was added to this solution.
(6.75 mmol) was added, and the mixture was stirred and mixed at 125 ° C. for 1 hour to obtain a uniform solution. After cooling to room temperature, 40 ml of titanium tetrachloride (0.
(36 mol) was added dropwise over 1 hour.
Then, the temperature of this mixed solution was raised to 110 ° C. over 2 hours, and when it reached 110 ° C., 0.54 ml of diisobutyl phthalate was added, and the mixture was kept under stirring at 110 ° C. for 2 hours. After the completion of the reaction for 2 hours, the solid part was collected by filtration, resuspended in 200 ml of TiCl ₄ , and then the reaction was carried out again at 110 ° C. for 2 hours. After the reaction is completed, the solid part is collected again by hot filtration,
It was sufficiently washed with decane and hexane until no free titanium compound was detected in the washing liquid. The composition of the solid Ti catalyst is 2.1% by weight of titanium, 57% by weight of chlorine, 18.0% of magnesium, and 21.9% of diisobutyl phthalate.
% By weight.

[Preliminary Polymerization] Inner volume of 1 L with N ₂ substitution
Into the autoclave of No. 3, 200 ml of purified n-hexane, 50 mmol of triethylaluminum, 10 mmol of cyclohexylmethyldimethoxysilane, 50 mmol of diethylaluminum chloride and 5 mmol of solid Ti catalyst component in terms of Ti atom were charged, and then 3-methyl-1.
10 g of butene were introduced. The temperature during this period is 15
Hold at ℃. After 120 minutes, the reaction was stopped and the inside of the autoclave was sufficiently replaced with N ₂ . The solid portion of the obtained slurry was washed 5 times with purified n-hexane to obtain titanium-containing poly-3-methyl-1-butene. As a result of analysis, solid Ti
8.0 g of 3-methyl-1-butene was polymerized with respect to 1 g of the catalyst component.

[Main Polymerization] 0.43 kg of propylene was charged into an autoclave having an internal volume of 2 L, which had been subjected to N ₂ substitution,
Triethylaluminum (1.64 mmol), ethyltriethoxysilanene (0.164 mmol), and hydrogen gas were charged so that the gas concentration in the gas phase would be 0.1 mol%, and then the internal temperature of the autoclave was raised to 65 ° C. 5. The titanium-containing poly-3-methyl-1-butene as a Ti atom.
Charged 56 × 10 ⁻³ mmol. Then, the internal temperature of the autoclave was raised to 70 ° C. and polymerization was carried out for 2 hours. After completion of the polymerization, unreacted propylene was purged to obtain a white granular polymer. The obtained polymer was vacuum dried at 70 ° C. for 1 hour. The results are shown in Table 1.

Example 2 In the main polymerization of Example 1, the same operation as in Example 1 was carried out except that ethyl silicate was used instead of ethyltriethoxysilane. The results are shown in Table 1.

Example 3 In the prepolymerization of Example 1, propylene was used instead of 3-methyl-1-butene, and in the main polymerization, cyclohexylmethyldimethoxysilane 0.0164 mm was used instead of 0.164 mmol of ethyltriethoxysilane.
was performed in the same manner as in Example 1 except that 0.42 mmol of ethyl silicate and 0.492 mmol of ethyl silicate were used in combination. The results are shown in Table 1.

Examples 4 to 7 In the main polymerization of Example 1, in place of 0.164 mmol of ethyltriethoxysilane, 0.492 mmol of dodecyltriethoxysilane and 0.0164 mmol of cyclohexylmethyldimethoxysilane were used in combination (Example 4), Octyltriethoxysilane 0.492mmol
And cyclohexylmethyldimethoxysilane 0.0164
mmol combination (Example 5), combination of 0.492 mmol pentyltriethoxysilane and 0.0164 mmol cyclohexylmethyldimethoxysilane (Example 6),
Combined use of 0.492 mmol of ethyl silicate and 0.0164 mmol of diisopropyldimethoxysilane (Example 7)
The same operation as in Example 1 was performed except that The results are shown in Table 1.

Examples 8 and 9 In the main polymerization of Example 3, ethylene gas was introduced so that the ethylene content in the polymer was 0.2 wt% (Example 4) and 0.4 wt% (Example 5). Example 3 except that
The same operation was performed. The results are shown in Table 1.

Example 10 The same operation as in Example 1 was carried out except that t-butylethyldimethoxysilane was used instead of cyclohexylmethyldimethoxysilane in the prepolymerization of Example 1.
The results are shown in Table 1.

Examples 11 to 13 In the prepolymerization of Example 1, instead of diethyl aluminum chloride, ethyl aluminum dichloride (Example 11), ethyl aluminum sesquichloride (Example 12), titanium tetrachloride (Example 13). The same operation as in Example 1 was performed except that was used. The results are shown in Table 1.

Example 14 The same procedure as in Example 1 was carried out except that vinylcyclohexane was used in place of 3-methyl-1-butene in the prepolymerization of Example 1. As a result of the analysis, 1.8 g of vinylcyclohexane was polymerized with respect to 1 g of the solid Ti catalyst component. The results are shown in Table 1.

Examples 15 and 16 In the main polymerization of Example 1, ethylene gas was introduced so that the ethylene content in the polymer was 0.2 wt% (Example 1
5) and 0.35 wt% (Example 16) except that the same operation as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 1 [Preliminary Polymerization] After charging 200 ml of purified n-hexane, 50 mmol of diethylaluminum chloride, and 3.5 g of titanium trichloride manufactured by Marubeni Solvay Co., into an autoclave having an internal volume of 1 L, which had been subjected to N ₂ substitution. , 3-methyl-1-
21 g of butene were introduced. The temperature during this period is 40 ° C.
Held in. After 120 minutes, the reaction was stopped and the inside of the autoclave was sufficiently replaced with N ₂ . The solid portion of the obtained slurry was washed 5 times with purified n-hexane to obtain titanium-containing poly 3
-Methyl-1-butene was obtained. As a result of the analysis, 3.1 g of 3-methyl-1-butene was polymerized with respect to 1 g of titanium trichloride.

[Main Polymerization] 0.43 Kg of propylene was charged into an autoclave having an internal volume of 2 L which had been subjected to N ₂ substitution,
After charging 2.33 mmol of diethylaluminum chloride and hydrogen gas so that the gas concentration in the gas phase would be 1.1 mol%, the internal temperature of the autoclave was raised to 65 ° C.,
Titanium-containing poly-3-methyl-1-butene was charged in an amount of 20 mg in terms of titanium trichloride. Then, the internal temperature of the autoclave was raised to 70 ° C. and polymerization was carried out for 2 hours. After completion of the polymerization, unreacted propylene was purged to obtain a white granular polymer. The obtained polymer was vacuum dried at 70 ° C. for 1 hour. The results are shown in Table 1.

Comparative Example 2 In the prepolymerization of Example 2, the same operation as in Example 2 was performed except that diethylaluminum chloride was not used. The results are shown in Table 1.

Comparative Examples 3 to 4 In Example 1, prepolymerization was not performed, and dicyclopentyldimethoxysilane was used in place of ethyltriethoxysilane in the main polymerization (Comparative Example 3), and ethyltriethoxysilane was not used. The same operation as in Example 1 was performed except for (Comparative Example 4). The results are shown in Table 1.

Comparative Example 5 The procedure of Example 1 was repeated, except that cyclohexylmethyldimethoxysilane was not used in the prepolymerization of Example 1. The results are shown in Table 1.

Comparative Examples 6 to 7 The same as Example 1 except that the hydrogen concentration in the main polymerization of Example 1 was changed and the melt flow rates were 0.05 (Comparative Example 6) and 19 (Comparative Example 7). The operation was performed. The results are shown in Table 1.
It was shown to.

[0070]

[Table 1]

Claims (2)

[Claims] 1. A melt flow rate of 0.1 to 10 g / 1.
0min, isotactic pentad fraction 0.85
˜0.94, the boiling heptane insoluble content is 97.5% by weight or more, and the concentration of titanium atoms remaining in the polymer is 3
A propylene homopolymer having a concentration of ppm or less and a chlorine atom concentration of 30 ppm or less. 2. A melt flow rate of 0.1 to 10 g / 1.
0min, isotactic pentad fraction 0.85
˜0.94, the boiling heptane insoluble content is 97.5% by weight or more, and the concentration of titanium atoms remaining in the polymer is 3
ppm or less, the concentration of chlorine atoms is 30 ppm or less, the monomer unit based on propylene is 95 wt% or more,
A propylene-α-olefin random copolymer having 5% by weight or less of a monomer unit based on an α-olefin other than propylene.