JPH11100412A - Highly stereoregular polypropylene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject polypropylene exhibiting extremely high rigidity and heat resistance and narrow in mol.wt. distribution by specifying the relation of number-average mol.wt. to melting enthalpy, weight-average mol.wt., and the like. SOLUTION: This highly stereoregular polypropylene has (A) the relation of number-average mol.wt. (Mn) to melting enthalpy [ΔH(j/g)] and satisfying the inequality: ΔH>=131.85(Mn)<-0.0715> -2.0, (B) a main elusion peak half width (by a temperature-programmed fractionation method) of <=3 deg.C, (C) a weight- average mol.wt. (Mw) of 10,000-700,000, and (D) an Mw/Mn ratio of 1.0-3.5, preferably 1.0-2.5. It is further preferable that (E) the absence of a different kind of bond caused by a 2, 1 insertion reaction and a 1, 3 insertion reaction and (F) the absence of a double bond at the molecular terminals are confirmed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high stereoregularity polypropylene, and more particularly to a high stereoregularity polypropylene having a narrow molecular weight distribution and a high stereoregularity and exhibiting extremely high rigidity and heat resistance. is there.

[0002]

2. Description of the Related Art Since polypropylene is a crystalline polymer, it has excellent rigidity, tensile strength, heat resistance, chemical resistance, optical properties, workability, etc., and has a light specific gravity compared to polystyrene and the like. It is widely used in the fields of various injection molded products, containers, packaging materials and the like. However, in order to further expand the field of use of this polypropylene, it is necessary to improve the rigidity and heat resistance, which are inferior to polystyrene and ABS resins, among the above-mentioned properties. It is known that the rigidity and heat resistance are improved as the stereoregularity of the polymer is increased, and further improvement of the stereoregularity is desired.

[0003] Catalysts for producing polypropylene are mainly
A solid catalyst component composed of titanium, magnesium, chlorine and an electron donating compound and a catalyst system composed of an organoaluminum compound are used. By adding an organosilicon compound having an alkoxy group to the catalyst system, a three-dimensional polymer produced is obtained. It is known that regularity is improved. However, even in the polypropylene produced by this catalyst system, the stereoregularity and molecular weight distribution are not sufficiently satisfactory.

On the other hand, in recent years, it has been known that propylene is polymerized using a catalyst comprising a combination of a metallocene and an aluminoxane, which is different from a conventional catalyst system, to obtain stereoregular polypropylene having a narrow molecular weight distribution. For example, propylene is polymerized by using a catalyst comprising a silicon-bridged metallocene having a specific structure and an aluminoxane to obtain a highly stereoregular polypropylene having a narrow molecular weight distribution (JP-A-3-12406, JP-A-3-3406). 1240
No. 7, "CHEMISTRY LETTERS, 1853 (1989)"). The polypropylene obtained by the above method has a narrow molecular weight distribution, a relatively high stereoregularity, a high melting point, and a high rigidity as compared with polypropylene obtained from a conventional metallocene catalyst. Even in polypropylene produced by the catalyst system, stereoregularity is not fully satisfactory. Further, in the above method, since propylene polymerization is carried out in the absence of hydrogen, a double bond is present at one end of the polymer, which may impair chemical stability depending on use conditions. Improvements are desired.

Japanese Patent Application Laid-Open No. 8-325327 discloses that propylene is polymerized in the presence of hydrogen using a catalyst comprising a chiral silicon-bridged metallocene and its meso-form and an aluminoxane, and one end of a polymer having a narrow molecular weight distribution. A highly stereoregular polypropylene having no double bond is obtained. However, even in the polypropylene produced by this catalyst system, the stereoregularity and the molecular weight distribution are not sufficiently satisfactory.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly stereoregular polypropylene having a narrow molecular weight distribution and exhibiting extremely high rigidity and heat resistance.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have succeeded in producing polypropylene having a narrow molecular weight distribution and extremely high stereoregularity. The present inventors have found that polypropylene having the specific structure has extremely high rigidity and heat resistance, and have completed the present invention.

That is, the present invention provides the following highly stereoregular polypropylene. (1) Number average molecular weight Mn and melting enthalpy ΔH (J
/ G) satisfies the relationship of ΔH ≧ 131.85 (Mn) ^−0.0715 −2.0 (1), and the half-width of the main elution peak in the temperature rising fractionation method is 3 ° C. or less, and Weight average molecular weight Mw
Is 10,000 to 700,000 and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.0 to
3.5. High stereoregularity polypropylene characterized by being 3.5. (2) Ratio M between weight average molecular weight Mw and number average molecular weight Mn
The highly stereoregular polypropylene according to (1), wherein w / Mn is 1.0 to 2.5. (3) According to the nuclear magnetic resonance spectrum, there is no hetero bond caused by the 2,1 insertion reaction and the 1,3 insertion reaction,
And the highly stereoregular polypropylene according to any one of (1) and (2), wherein it is confirmed that no terminal double bond is present. (4) According to the nuclear magnetic resonance spectrum, the isotactic pentad fraction (mmmm) is 99% or more and the syndiotactic pentad fraction (rrrr) is 0.1% or less. Highly stereoregular polypropylene according to any of the above.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The highly stereoregular polypropylene of the present invention has a number average molecular weight Mn and a melting enthalpy ΔH.
(J / g) satisfies the relationship of ΔH ≧ 131.85 (Mn) ^−0.0715 −2.0 (1), and the half value width of the main elution peak in the temperature rising fractionation method is 3 ° C. or less. And the weight average molecular weight Mw
Is 10,000 to 700,000 and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.0 to
3.5.

[0010] Among the properties of the stereoregular polypropylene according to the present invention, the melting enthalpy ΔH was calculated based on the measurement results according to the following method. That is, the polypropylene was heated from room temperature to 220 ° C. under a temperature rising condition of 500 ° C./min using a DSC7 differential scanning calorimeter (manufactured by Perkin-Elmer Co.), and kept at the same temperature for 3 minutes.
The temperature was lowered to 50 ° C. at 30 ° C./min, kept at the same temperature for 3 minutes, and then the melting enthalpy at 100 to 175 ° C. was measured under the condition of increasing the temperature to 190 ° C. at 10 ° C./min.

The relationship between the number average molecular weight (Mn) and the enthalpy of fusion ΔH, which is a characteristic of the stereoregular polypropylene according to the present invention, is represented by the following formula: ΔH ≧ 131.85 (Mn) ^{−0.0715−2.0} (1) And preferably, the relationship of ΔH ≧ 131.85 (Mn) ^{−0.0715−1.5} (2). The stiffness of the polymer is the melting enthalpy Δ
Since it correlates with H, the rigidity of the polymer can be known by determining the relationship between the number average molecular weight (Mn) and the enthalpy of fusion ΔH. If the melting enthalpy ΔH is large, the rigidity is high, and if it is small, the rigidity is low.

Further, among the characteristics of the stereoregular polypropylene according to the present invention, the half-width of the main elution peak in the temperature rising fractionation method is based on the result of measurement by liquid chromatography (HPLC) according to the following method. Then, the relationship between temperature and concentration is graphed, and the elution temperature width at half the peak height is determined. That is, 3.75 mg of the polymer is o
Using a sample dissolved in 20 ml of dichlorobenzene, injecting 2 ml of the sample solution into the column under the condition of 135 ° C., gradually cooling the mixture to room temperature at 10 ° C./hr, adsorbing the polymer to the filler, and adding o-dichlorobenzene 2 ml / min
The column temperature is increased at 20 ° C./hr while injecting at, and the polymer concentration eluted at each temperature is determined by measuring with an infrared detector. Column is 10.7mmφ ×
Chromosolve P is used as a filler at 300 mm, and the measurement is performed by measuring within a column temperature distribution of ± 0.2 ° C. A wavelength of 3.41 μm is used for detection. The amount of the polymer eluted at room temperature was defined as the amount of the soluble part at room temperature.

Since the stereoregularity of a polymer depends on the elution temperature, the distribution of the stereoregularity of the polymer can be known by determining the relationship between the elution temperature and the polymer concentration by a temperature-rise fractionation method. If the half-width of the main elution peak in the temperature rising fractionation method is large, the stereoregularity distribution is wide, and if it is small, the stereoregularity distribution is narrow. The half-width of the main elution peak in the temperature rising fractionation method, which is a characteristic of the stereoregular polypropylene according to the present invention, is 3 ° C or less, and preferably 2.5 to
2.9 ° C.

Further, among the characteristics of the stereoregular polypropylene according to the present invention, the weight average molecular weight (Mw) and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) are as follows. Calculated based on the measurement results of gel permeation chromatography (GPC) according to the following method. That is, 1,2,4-trichlorobenzene having a polymer concentration of 0.1% by weight / volume (BHT300p
pm) and a mixed polystyrene gel column (for example, GMH manufactured by Tosoh Corporation).
6HT) at 145 ° C. and at a flow rate of 1.0 ml / min.
Determined by measuring in. An infrared detector is used for detection, and a wavelength of 3.41 μm is used.

The stereoregular polypropylene according to the present invention has a weight-average molecular weight (Mw) of 10,000 to 10,000.
700,000, preferably 10,000 to 50
It is 0000. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), which is a characteristic of the stereoregular polypropylene according to the present invention, is 1.0 to 3.5, preferably 1.0 to 2. 5 The ratio (Mw / M) of the above weight average molecular weight (Mw) to number average molecular weight (Mn)
n) is a measure of the molecular weight distribution and its ratio (Mw / Mn)
If the is large, the molecular weight distribution is wide, and if it is small, the molecular weight distribution is narrow.

Among the properties of the stereoregular polypropylene according to the present invention, the above and the above are calculated based on the measurement results of ¹³ C nuclear magnetic resonance spectrum according to the following method. That is, 200 mg of a polymer was treated at 135 ° C. with 1,2,4-trichlorobenzene / deuterated benzene (C ₆ D
₆ ) Using a sample dissolved in 3 ml of a mixed solvent having a weight ratio of 9/1, 500 MHz, 130 ° C., the number of integrations of 10,000
Determined by measuring at 00 times. As a measuring device, for example, Lambda-500 manufactured by JEOL Ltd.
An NMR measurement device is used.

In the present invention, "heterogeneous bond resulting from 2,1 insertion reaction and 1,3 insertion reaction" is defined by T. Tsutsui.
tsui) et al., based on the method proposed in "POLYMER, 30 , 1350 (1989)", which results from 2,1 and 1,3 insertion reactions in polypropylene molecular chains measured by ¹³ C nuclear magnetic resonance spectrum. This is the percentage of heterogeneous bonds.

A characteristic of the stereoregular polypropylene according to the present invention is that the presence of foreign bonds due to the 2,1 insertion reaction and the 1,3 insertion reaction is not observed. In addition,
When a known ordinary titanium-based catalyst is used for the polymerization of propylene, the polymerization proceeds by a 1,2-insertion reaction, whereas when a known metallocene catalyst is used, a certain degree of 2,1-insertion reaction and 1 , 3 insertion reaction has occurred, and it is known that a certain amount of heterogeneous bonds exist in the obtained polypropylene.

In the present invention, the terminal double bond is determined by a ¹³ C nuclear magnetic resonance spectrum based on the method described in “POLYMER, 30 , 1717 (1989)” by Hayashi et al. It is the ratio of double bonds present at the end of the molecule. A characteristic of the stereoregular polypropylene according to the invention is that there are no terminal double bonds. As described above, if a double bond is present at the end of a polypropylene molecule, the chemical stability of the polypropylene may be impaired due to the double bond participating in the reaction depending on the use conditions. The original characteristics may not be exhibited.

The terms "isotactic pentad fraction (mmmm)" and "syndiotactic pentad fraction (rrrr)" used in the present invention refer to "Macromolecules, 6 ,," by A. Zambelli and others. 925 (197
3) In pentad units in the polypropylene molecular chain measured by the ¹³ C nuclear magnetic resonance spectrum proposed in
It means isotactic fraction and syndiotactic fraction. The method for determining the assignment of peaks in the measurement of the ¹³ C nuclear magnetic resonance spectrum is described by A. Zambe.
lli) et al., according to the attribution proposed in "Macromolecules, 8 , 687 (1975)".

Isotactic pentad fraction of properties of stereoregular polypropylene according to the present invention (mmmm)
Is the ratio of propylene monomer units having five consecutive meso bonds present in all propylene monomer units in the polypropylene molecule, as described above. Therefore, the higher the isotactic pentad fraction (mmmm), the higher the isotacticity. A characteristic of the polypropylene of the present invention is that the isotactic pentad fraction (mmmm) is 99.0% or more;
Preferably 99.1% or more, particularly preferably 99.5%
That is all.

The stereoregular polypropylene of the present invention that satisfies the above-mentioned properties and the above-mentioned properties has very few hetero-bonds and racemic linkages, and has a very high isotacticity composed of a very highly controlled meso-linkage. It shows the nature. The syndiotactic pentad fraction (rrr) of the properties of the stereoregular polypropylene according to the present invention.
r) is the ratio of five consecutive racemic-bonded propylene monomer units present in all propylene monomer units in the polypropylene molecule. Therefore, a lower syndiotactic pentad fraction (rrrr) indicates lower syndiotacticity. The properties of the polypropylene of the present invention include the syndiotactic pentad fraction (r
(rrr) is 0.1% or less, preferably 0.08% or less, particularly preferably 0.05% or less.

As long as the stereoregular polypropylene of the present invention satisfies the above-mentioned properties, its production method is not limited, but the polymerization is carried out using a polymerization catalyst capable of exhibiting high polymerization activity and stereoregularity. Thereafter, it is preferable to separate the obtained polypropylene by preparative heating and fractionation. Examples of such a polymerization catalyst and a method for producing a polyolefin using the catalyst include (A) (a) a titanium compound,
(B) a magnesium compound, (c) a solid titanium catalyst component formed from an electron donor and optionally a halide, (B) an organoaluminum compound, and optionally (C) an organosilicon compound. And a method of performing polymerization using the catalyst. Hereinafter, a method of producing using the catalyst and a method of preparative heating and fractionation will be described. [I] Each catalyst component (A) Solid titanium catalyst component The solid titanium catalyst component contains titanium, magnesium, and an electron donor, and includes the following (a) a titanium compound, (b) a magnesium compound, (C) It is formed from an electron donor and, if necessary, a halide. (A) Titanium compound As the titanium compound, a titanium compound represented by the general formula (I) TiX ¹ _p (OR ¹ ) _4-p (I) can be used.

In the above formula (I), X ¹ represents a halogen atom, preferably a chlorine atom. R ¹ has ¹ carbon atom
It represents 10 to 10 hydrocarbon groups, and particularly preferably a straight-chain or branched-chain alkyl group. When a plurality of R ¹ are present, they may be the same or different. p shows the integer of 0-4. Specific examples of the titanium compound represented by the general formula (I) include tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, Tetraalkoxy titanium such as tetracyclohexyloxytitanium and tetraphenoxytitanium; titanium tetrachloride such as titanium tetrachloride, titanium tetrabromide and titanium tetraiodide; methoxytitanium trichloride; ethoxytitanium trichloride; propoxytitanium trichloride; n -Trihalogenated alkoxytitanium such as butoxytitanium trichloride, ethoxytitanium tribromide, dimethoxytitanium dichloride, diethoxytitanium dichloride, diisopropoxytitanium dichloride, di-
n-propoxytitanium dichloride, dialkoxytitanium dihalides such as diethoxytitanium dibromide, trimethoxytitanium chloride, triethoxytitanium chloride,
Monohalogenated trialkoxytitaniums such as triisopropoxytitanium chloride, tri-n-propoxytitanium chloride and tri-n-butoxytitanium chloride can be mentioned. Among these, a titanium compound having a high halogen content, particularly titanium tetrachloride, is preferred. These titanium compounds may be used alone or in combination of two or more. (B) Magnesium compound As the magnesium compound, a magnesium compound represented by the following general formula (II): MgR ² R ³ (II) can be used.

In the above general formula (II), R^Twoas well as
R^ThreeIs a hydrocarbon group, OR^FourGroup (R ^FourIs a hydrocarbon group),
Or a halogen atom. More specifically, with hydrocarbon groups
And an alkyl group having 1 to 12 carbon atoms, cycloalkyl
Group, aryl group, aralkyl group, etc.^FourAs a basis
Is R^FourIs an alkyl group having 1 to 12 carbon atoms,
Kill groups, aryl groups, aralkyl groups, etc.
Represents chlorine, bromine, iodine, fluorine and the like. Ma
R^TwoAnd R^ThreeMay be the same or different.

Specific examples of the magnesium compound represented by the above general formula (II) include dimethylmagnesium,
Diethyl magnesium, diisopropyl magnesium,
Dibutyl magnesium, dihexyl magnesium, dioctyl magnesium, ethyl butyl magnesium, diphenyl magnesium, dicyclohexyl magnesium,
Dimethoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, dihexyloxy magnesium, dioctoxy magnesium, diphenoxy magnesium, dicyclohexyloxy magnesium, ethyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride,
Isopropyl magnesium chloride, isobutyl magnesium chloride, t-butyl magnesium chloride, phenyl magnesium bromide, benzyl magnesium chloride, ethyl magnesium bromide, butyl magnesium bromide, phenyl magnesium chloride, butyl magnesium iodide, butoxymagnesium chloride, cyclohexyloxymagnesium chloride, phenoxymagnesium Chloride, ethoxymagnesium bromide, butoxymagnesium bromide, ethoxymagnesium iodide, magnesium chloride, magnesium bromide, magnesium iodide and the like.

The above magnesium compound is a metal magnet.
Prepared from compounds containing calcium or magnesium
be able to. One example is the use of halo on metallic magnesium.
Genides and general formula X^Two _mM (OR^Five) _nmA represented by
Lucoxy group-containing compound (wherein, X^TwoIs hydrogen atom, halogen
A hydrocarbon atom having 1 to 20 carbon atoms, and M is
Indicates boron, carbon, aluminum, silicon or phosphorus atom
And R^FiveRepresents a hydrocarbon group having 1 to 20 carbon atoms.
n shows the valence of M and n> m ≧ 0. ) Contact
Law.

Examples of the halide include silicon tetrachloride, silicon tetrabromide, tin tetrachloride, tin tetrabromide, hydrogen chloride and the like. Among these, silicon tetrachloride is preferred. Examples of the hydrocarbon group of X ² and R ⁵ include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, an octyl group, a cyclohexyl group, an allyl group, and a propenyl group. And alkenyl groups such as butenyl group, aryl groups such as phenyl group, tolyl group and xylyl group, and aralkyl groups such as phenethyl and 3-phenylpropyl groups. Among them, an alkyl group having 1 to 10 carbon atoms is particularly preferable. As another example, a method in which a halide is brought into contact with a magnesium alkoxy compound represented by Mg (OR ⁶ ) ₂ (in the formula, R ⁶ represents a hydrocarbon group having 1 to 20 carbon atoms).

The above-mentioned halide is the same as described above. As the above R ⁶ , a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group,
Alkyl groups such as hexyl group and octyl group, alkenyl groups such as cyclohexyl group, allyl group, propenyl group and butenyl group; aryl groups such as phenyl group, tolyl group and xylyl group; aralkyl groups such as phenethyl and 3-phenylpropyl group. And the like. Among these, especially those having 1 to 1 carbon atoms
Ten alkyl groups are preferred.

The above magnesium compounds may be used alone or in combination of two or more. Further, it may be used as a mixture with a halogen or the like. Also,
It may contain an electron donor such as an oxygen-containing compound such as alcohol and ether, and may contain other metal elements such as Al, Zn, and Si. Further, a support such as silica, alumina, and polystyrene may be included. (C) Electron Donor Examples of the electron donor include alcohols, phenols, ketones, aldehydes, carboxylic acids, malonic acids, esters of organic or inorganic acids, and ethers such as monoether, diether and polyether. And nitrogen-containing electron donors such as ammonia, amines, nitriles and isocyanates. Among these, esters of polycarboxylic acids are preferred,
More preferred are esters of aromatic polycarboxylic acids. Particularly, esters of aromatic dicarboxylic acids are preferred. Further, an aliphatic hydrocarbon in which the organic group in the ester portion is linear, branched or cyclic is preferable.

Specifically, phthalic acid, naphthalene-1,
2-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, 5,6,7,8-tetrahydronaphthalene-1,2
Methyl, ethyl, n- of dicarboxylic acids such as dicarboxylic acid, 5,6,7,8-tetrahydronaphthalene-2,3-dicarboxylic acid, indane-4,5-dicarboxylic acid and indane-5,6-dicarboxylic acid; Propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methyl Pentyl, 4-methylpentyl, 1-ethylbutyl, 2-ethylbutyl,
n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 2-ethylhexyl,
3-ethylhexyl, 4-ethylhexyl, 2-methylpentyl, 3-methylpentyl, 2-ethylpentyl,
Examples thereof include dialkyl esters such as 3-ethylpentyl. Among these, phthalic acid diesters are preferable, and a linear or branched aliphatic hydrocarbon having 4 or more carbon atoms in the organic group in the ester portion is preferable.

As specific examples, di-n-butyl phthalate, diisobutyl phthalate, di-n-heptyl phthalate, diethyl phthalate and the like can be preferably mentioned. These aromatic carboxylic acid diester compounds may be used alone or in combination of two or more. (B) Organoaluminum Compound As the organoaluminum compound, those having an alkyl group, a halogen atom, a hydrogen atom, or an alkoxy group, aluminoxanes, and mixtures thereof can be used. Specifically, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trialkylaluminum such as trioctylaluminum, diethylaluminum monochloride,
Examples thereof include dialkylaluminum monochloride such as diisopropylaluminum monochloride, diisobutylaluminum monochloride, and dioctylaluminum monochloride; alkylaluminum sesquihalides such as ethylaluminum sesquichloride; and chain aluminoxanes such as methylaluminoxane. Among these organoaluminum compounds, trialkylaluminum having a lower alkyl group having 1 to 5 carbon atoms, particularly trimethylaluminum, triethylaluminum, tripropylaluminum and triisobutylaluminum are preferable. These organoaluminum compounds may be used alone or in combination of two or more. (C) Organosilicon compound It is preferable to add an organosilicon compound to the polymerization, if necessary. As this organosilicon compound, Si-O
Preferred are organosilicon compounds having a -C bond.

A typical example of this is represented by the general formula R ⁷ _S Si
A silicate represented by (OR ⁸ ) _4-S can be mentioned. In the formula, R ⁷ represents a hydrocarbon group or a halogen atom, wherein the hydrocarbon group is an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, or the like; and the halogen atom is a chlorine atom or the like. Is mentioned. R ⁸ represents a hydrocarbon group, and includes an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group,
And an alkoxyalkyl group. s is 0 or 1
Indicates an integer of 3. When there are a plurality of R ⁷ or R ⁸ , they may be the same or different.

Further, siloxanes, silyl esters of carboxylic acids and the like can be mentioned. Specific examples of the above include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexyl-1 , 1,2-trimethylpropyldimethoxysilane, α-naphthyl-1,
1,2-trimethylpropyldimethoxysilane, n-tetradecanyl-1,1,2-trimethylpropyldimethoxysilane, cyclopentylmethyldimethoxysilane,
Cyclopentylethyldimethoxysilane, cyclopentylpropyldimethoxysilane, cyclopentyl-t-butyldimethoxysilane, cyclopentyl-1,1,2-
Trimethylpropyldimethoxysilane, dicyclopentyldimethoxysilane, cyclopentylcyclohexyldimethoxysilane, t-butylmethyldimethoxysilane,
t-butylethyldimethoxysilane, t-butylpropyldimethoxysilane, di-t-butyldimethoxysilane, diisopropyldimethoxysilane, isopropylisobutyldimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyl Triethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, γ-
Aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, methyl-t-butoxymethoxysilane, isopropyl-t-butoxymethoxysilane, cyclopentyl-t-butoxymethoxysilane, 1,1, 2
-Trimethylpropyltrimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyltris (β-methoxyethoxy) silane, vinyltrisacetoxysilane, dimethyltetraethoxydisiloxane and the like. These organic silicon compounds may be used alone or in combination of two or more.

As the organosilicon compound, Si-
An organic silicon compound having a Si-OC bond by reacting a silicon compound having no OC bond and an organic compound having an OC bond in advance or by reacting during the polymerization of an α-olefin. Can also be mentioned. Specific examples include those in which silicon tetrachloride is reacted with an alcohol. [II] Adjustment of Solid Titanium Catalyst Component The adjustment of the solid titanium catalyst component is performed by the above-mentioned (a) titanium compound, (b) magnesium compound, (c) electron donor,
If necessary, the halide may be brought into contact with an ordinary method, but the contact is preferably carried out according to the following amount, conditions and procedure.

The amount of the titanium compound to be used is generally 0.5 to 100 mol, preferably 1 to 50 mol, per 1 mol of magnesium of the above magnesium compound. The amount of the electron donor to be used is usually 0.01 to 10 mol, preferably 0.1 to 10 mol, per 1 mol of magnesium of the magnesium compound.
It is good to make it the range of 05-1.0 mol. Further, silicon tetrachloride may be added as a halide.

The contact temperature is usually -20 to 200.
° C, preferably in the range of 20 to 150 ° C,
The contact time is usually 1 minute to 24 hours, preferably 10 minutes.
It may be in the range of minutes to 6 hours. This contact procedure is not particularly limited. For example, the components may be brought into contact in the presence of an inert solvent such as a hydrocarbon, or the components may be diluted with an inert solvent such as a hydrocarbon in advance and brought into contact.
Examples of the inert solvent include aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, n-heptane, n-octane and isooctane, aromatic hydrocarbons such as benzene, toluene and xylene, and mixtures thereof. Can be mentioned.

It is preferable that the contact with the titanium compound is carried out twice or more so that the titanium compound is sufficiently supported on the magnesium compound serving as a catalyst carrier. The solid catalyst component obtained by the above contact may be washed with an inert solvent such as a hydrocarbon.
This inert solvent may be the same as described above. The solid product can also be stored dry or in an inert solvent such as a hydrocarbon. [III] Polymerization The amount of the catalyst component used is such that the solid catalyst component (A) is usually in the range of 0.0005 to 1 mmol per liter of reaction volume in terms of titanium atoms. Is used, and the organoaluminum compound as the component (B) has an aluminum / titanium atomic ratio of usually 1 to 1000,
Preferably, an amount is used so as to be in the range of 10 to 500. When the atomic ratio is within the above range, the catalytic activity becomes high. The amount of the electron-donating compound (C) is such that the molar ratio of the (C) electron-donating compound / (B) organoaluminum compound is usually in the range of 0 to 50, preferably 0.01 to 20. Is used. When the molar ratio is within the above range, a sufficient catalytic activity can be obtained.

In the polymerization of olefin in the present invention, if desired, the olefin may be preliminarily polymerized first, followed by main polymerization. In this case, ethylene, propylene, 1-butene, and the like are mixed in the presence of a catalyst obtained by mixing (A) the solid catalyst component, (B) the organoaluminum compound, and (C) the electron donating compound at a predetermined ratio.
An olefin such as 1-hexene is usually prepolymerized at a temperature in the range of 1 to 100 ° C. at normal pressure to a pressure of about 50 kg / cm ² G, and then the components (B) and (C) are prepolymerized with the prepolymerized product. The olefin is fully polymerized in the presence. The type of polymerization in this main polymerization is not particularly limited, and can be applied to any of solution polymerization, slurry polymerization, gas phase polymerization, bulk polymerization, and the like, and can be applied to both batch polymerization and continuous polymerization. Yes, it is applicable to two-stage polymerization and multi-stage polymerization under different conditions.

Further, the reaction conditions are not particularly limited, and the polymerization pressure is usually from atmospheric pressure to 200 kg / cm.
² G, preferably ^{2 to} 80 kg / cm ² G, the polymerization temperature is usually 10 to 200 ° C., preferably 40 to 100 ° C.
It is appropriately selected in the range of ° C. The polymerization time depends on the type of the starting olefin and the polymerization temperature and cannot be determined unconditionally, but is usually 5 minutes to 20 hours, preferably 10 minutes.
It takes about 10 minutes to 10 minutes.

In the case of solution polymerization or slurry polymerization, examples of the solvent usable for polymerization include n-pentane, isopentane, n-hexane, n-heptane, and n-pentane.
Examples thereof include aliphatic hydrocarbons such as -octane and isooctane, aromatic hydrocarbons such as benzene, toluene and xylene, and mixtures thereof. Of these, n-heptane is preferable.

The molecular weight can be adjusted by adding a chain transfer agent, preferably by adding hydrogen. Also,
An inert gas such as nitrogen may be present. Further, as for the catalyst component in the present invention, the component (A), the component (B) and the component (C) may be mixed at a predetermined ratio, brought into contact with each other, and then an olefin may be immediately introduced to carry out polymerization. And after aging for about 0.2 to 3 hours after contact,
The polymerization may be carried out by introducing an olefin. Further, this catalyst component can be supplied by suspending in an inert solvent, an olefin or the like.

In the present invention, the post-treatment after the polymerization can be carried out by a conventional method. That is, in the gas phase polymerization method, after polymerization, the polymer powder derived from the polymerization vessel,
In order to remove olefins and the like contained therein, a nitrogen stream or the like may be passed. [V] Preparative temperature rise fractionation The high stereoregularity polypropylene of the present invention can be usually produced by preparative temperature rise fractionation of the polypropylene obtained by the above polymerization.

The preparative temperature raising and fractionation can be performed, for example, by a preparative temperature raising and fractionating apparatus as shown in FIG.

[0045]

FIG. 1 Examples of solvents that can be used include o-dichlorobenzene, para-xylene, trichlorobenzene, decalin and mixtures thereof, among which o-dichlorobenzene is preferred. Examples of usable column fillers include, for example, Chromosolve P, Celite # 560, sea sand, and porous fillers such as silanized silica gel. Among them, Chromosolve P is more preferable.

At this time, the separation temperature is usually from 0 to 135
° C, preferably 10 to 135 ° C. As a specific sorting method, for example, the following method can be mentioned. 20 g of the polypropylene powder obtained by the above polymerization was mixed with o-dichlorobenzene (BHT 500 ppm).
including. The same applies hereinafter. ) Dissolve in 200 ml at 135 ° C. After injecting this solution into the preparative heating / temperature separation device, 30
The polymer is adsorbed on the filler while the temperature is lowered to ° C. o
-1 while feeding dichlorobenzene at 10 ml / min.
The temperature is raised to 40 ° C., and the temperature is kept at the temperature for fractionation for 4 hours or more, preferably 5 hours or more. The eluate was fractionated at each fractionation temperature with a fraction collector, and each fraction was added to 2 liters of methanol while stirring to reprecipitate,
The polymer obtained after filtration is air-dried and further vacuum-dried for at least 8 hours.

[0047]

[Examples 1 to 4]

(1) Preparation of Solid Catalyst Component After replacing a three-necked flask with an internal volume of 0.5 liter with a stirrer with nitrogen gas, 80 ml of dehydrated heptane was added.
1, 4.0 g (35 mmol) of diethoxymagnesium
Was added. After heating to 80 ° C., 13.2 mmol of n-dibutyl phthalate were added. This solution was kept at 80 ° C., and 116 ml of titanium tetrachloride (1.06
Mol), and the mixture was stirred at an internal temperature of 110 ° C. for 2 hours to perform a loading operation. Then, it was sufficiently washed with dehydrated heptane. Further, 116 ml (1.06 mol) of titanium tetrachloride was added, and the mixture was stirred at an internal temperature of 110 ° C. for 2 hours to perform a second loading operation. Thereafter, washing was performed sufficiently using dehydrated heptane to obtain a solid catalyst component. (Titanium loading =
(2. 1) Propylene slurry polymerization A 1-liter stainless steel autoclave with an internal volume of 1 liter was sufficiently dried, and after replacement with nitrogen, 400 ml of dehydrated heptane at room temperature was added. 2.0 mmol of triethylaluminum, 0.25 mmol of dicyclopentyldimethoxysilane, and 0.005 mmol of the above solid catalyst component in terms of Ti atom were added, and hydrogen was introduced at 1 kg / cm ² G while stirring at a rotation speed of 400 rpm. Subsequently, while introducing propylene, 80 ° C., total pressure 8 kg / cm
^The temperature was raised to ² G and the temperature and pressure were maintained, and polymerization was carried out for 60 minutes while maintaining the temperature and pressure. Thereafter, the temperature was lowered and the pressure was released, and the contents were taken out and poured into 2 liters of methanol to precipitate polypropylene powder. It is filtered off, vacuum dried and
183 g of polypropylene were obtained. (3) Preparative temperature rise fractionation 20 g of polypropylene powder obtained by the above polymerization
Is dissolved at 135 ° C. in 200 ml of o-dichlorobenzene. After injecting this solution into a silica gel packed column (100 mmφ × 300 mm) of a preparative heating / temperature separation apparatus, the polymer is adsorbed to the filler while the temperature is lowered to 30 ° C. 30 ° C. while feeding the solution at 10 ml / min of o-dichlorobenzene
To 100 ° C. for 60 minutes and maintained for 1 hour, and then further raised to 105 ° C. for 5 minutes and maintained for 4 hours. Similarly, 110 ° C., 115 ° C., 120 ° C., 122
The temperature was increased to 5 ° C., 124 ° C., 126 ° C., and 128 ° C. over 5 minutes, and the holding was repeated for 4 hours. 122 ° C, 12
At each temperature of 4 ° C., 126 ° C., and 128 ° C., the polypropylene solution fractionated by the fraction collector was added to 2 liters of methanol with stirring to reprecipitate. Dried. The obtained polymers were Examples 1 to 4, and their physical properties were evaluated. The results are shown in Table 1. [Examples 5 to 7] (1) Preparation of solid catalyst component The same catalyst was prepared as in [Example 1]. (2) Propylene slurry polymerization The same polymerization as in [Example 1] was carried out except that the hydrogen filling pressure was 3.0 kg / cm ² G, and polypropylene 73 was used.
g was obtained. (3) Increasing the preparative temperature Separation The same operation as in [Example 1] was performed except that the preparative temperatures were 115 ° C, 120 ° C, and 125 ° C. The obtained polymers are Examples 5 to 7, and their physical properties are shown in Table 1. [Comparative Example 1] Catalyst preparation and polymerization were carried out in the same manner as in [Example 1] to obtain 183 g of polypropylene. The physical properties of the obtained polymer were evaluated as they were without fractionating and raising the temperature. The results are shown in Table 1. [Comparative Example 2] Except that the hydrogen filling pressure was set to 0.3 kg / cm ² G during polymerization of propylene slurry [Example 1]
The same catalyst preparation and polymerization as those described above were performed. Polypropylene 10
3 g were obtained. Without separating the resulting polymer by preparative heating and fractionation,
The physical properties were evaluated as they were. The results are shown in Table 1.

[0048]

[Table 1]

[0049]

According to the present invention, a highly stereoregular polypropylene having a narrow molecular weight distribution and exhibiting extremely high rigidity and heat resistance can be provided.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a preparative temperature raising / sorting apparatus used in the present invention.

FIG. 2 is a temperature rise fractionation chart of the highly stereoregular polypropylene of the present invention produced in Example 1.

Claims (4)

[Claims] 1. The number average molecular weight Mn and the melting enthalpy ΔH (J / g) satisfy the relationship of the following formula: ΔH ≧ 131.85 (Mn) ^{−0.0715−2.0} (1) Has a half-value width of 3 ° C. or less, and further has a weight average molecular weight Mw.
Is 10,000 to 700,000 and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.0 to
3.5. High stereoregularity polypropylene characterized by being 3.5. 2. Weight average molecular weight Mw and number average molecular weight M
The highly stereoregular polypropylene according to claim 1, wherein the ratio Mw / Mn of n is 1.0 to 2.5. 3. The method according to claim 1, wherein the nuclear magnetic resonance spectrum is 2,1.
The highly stereoregular polypropylene according to claim 1 or 2, wherein it is confirmed that a heterogeneous bond resulting from the insertion reaction and the 1,3 insertion reaction does not exist and that a terminal double bond does not exist. 4. According to a nuclear magnetic resonance spectrum, the isotactic pentad fraction (mmmm) is 99% or more;
The highly stereoregular polypropylene according to any one of claims 1 to 3, wherein a syndiotactic pentad fraction (rrrr) is 0.1% or less.