JP3398439B2 - Method for producing poly-α-olefin - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing poly-α-olefins. Specifically, isotactic poly-α
A method for producing a poly-α-olefin having good moldability and physical properties, using a catalyst comprising a catalyst component capable of producing an olefin and a catalyst component capable of producing a syndiotactic poly-α-olefin Regarding

[0002]

2. Description of the Related Art Syndiotactic poly-α-olefins, especially syndiotactic polypropylene, are described in, for example, JP-A-2-41303, JP-A-2-274703 and JP-A-2-274704. It is known that such a catalyst can be obtained by using a catalyst composed of a metallocene compound having a ligand in which two asymmetrical ligands are bridged and aluminoxane. The molded product obtained from this syndiotactic polypropylene is superior in transparency, gloss and flexibility to the molded product obtained from the conventional isotactic polypropylene, and its use as a new polypropylene is expected.

[0003]

However, syndiotactic polypropylene has a problem that it is inferior in moldability because it has a slower crystallization rate, that is, a solidification rate than isotactic polypropylene.

[0004]

In view of the above problems, the present inventors have made poly-α-excellent in moldability and various physical properties.
As a result of intensive studies on a method for obtaining an olefin, particularly polypropylene, it was found that the aforementioned object can be achieved by polymerizing an α-olefin in the presence of a specific catalyst, and the present invention has been completed. That is, the present invention provides a catalyst comprising a catalyst component capable of producing at least one isotactic poly-α-olefin and a catalyst component capable of producing at least one syndiotactic poly-α-olefin. Α below
A method for producing a poly-α-olefin, in particular polypropylene, characterized by polymerizing an olefin.

The catalyst component capable of producing the isotactic poly-α-olefin used in the method of the present invention has an isotactic pentad fraction of 0.7 or more as measured by ¹³ C-NMR analysis. Any catalyst can be used without limitation as long as it can produce a polymer having a value of 0.8 or more. Examples of such a catalyst component include a known Ziegler type catalyst containing titanium halide as a main component and a so-called metallocene catalyst containing a transition metal compound having a cyclopentadienyl ligand as a main component.

Examples of the metallocene catalyst capable of producing isotactic poly-α-olefin include, for example, JP-A-61-130314, JP-A-3-12406, JP-A-3-197516 and Angew. Che.
m. Int. Ed. Eng. 31 (1992). and the like, a catalyst comprising a metallocene compound and a cocatalyst can be mentioned. Specific examples of such metallocene compounds include, for example, ethylenebisindenylzirconium dichloride, ethylenebis (tetrahydroindenyl) zirconium dichloride, dimethylsilylenebis (dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (trimethylcyclopentadienyl). Examples thereof include enyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (2-methylindenyl) zirconium dichloride, and dimethylsilylenebis (2-methyl-4-isopropylindenyl) zirconium dichloride.

Further, as the cocatalyst, in addition to the following known aluminoxanes, Japanese Patent Publication No. 501501/1989,
Compounds capable of stabilizing a transition metal cation as described in JP-A-1-502036, for example, dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbenium tetrakis (pentafluorophenyl) borate. Or JP-A-3
Compounds exhibiting Lewis acidity as described in JP-A-179006, for example, magnesium chloride, alumina,
Tris (pentafluorophenyl) boron can be used. Aluminoxanes have the general formula [Chemical formula 1]

[0008]

[Chemical 1] And / or [Chemical formula 2]

[0009]

[Chemical 2] (Wherein R represents a hydrocarbon group having 1 to 10 carbon atoms and n represents an integer of 2 or more), and particularly methylaluminoxane in which R is a methyl group, n is 5 or more, preferably Those of 10 or more and 100 or less are used. The aluminoxanes may be mixed with some alkylaluminum compounds. Further, in addition, aluminoxane having two or more kinds of alkyl groups described in JP-A-2-247201, JP-A-3-103407, etc., and JP-A-63-198691 are described. Fine particulate aluminoxane, aluminum oxy compounds and the like obtained by contacting aluminoxane described in JP-A-2-167302, JP-A-2-167305 with water or an active hydrogen compound, and the like can also be preferably used. it can.

The catalyst component capable of producing the syndiotactic poly-α-olefin used in the method of the present invention has a syndiotactic pentad fraction of 0.6 or more as measured by ¹³ C-NMR analysis. Any catalyst that can produce a polymer having a value of 0.7 or more can be used without limitation. Suitable catalysts include metallocene catalysts containing a transition metal compound as a main component, particularly metallocene catalysts composed of a metallocene compound and a cocatalyst, for example, JP-A-2-413.
03, JP-A-2-274703, JP-A-2
Examples thereof include metallocene catalysts described in JP-A-274704 and JP-A-4-69394.

Specific examples of such metallocene compounds include isopropylidene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, cyclohexylidene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, diphenylmethylene. (Cyclopentadienyl) (9-fluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl)
(2,7-di-t-butyl-9-fluorenyl) zirconium dichloride, cyclohexylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl)
Zirconium dichloride, diphenylmethylene (cyclopentadienyl) (2,7-dit-butyl-9-fluorenyl) Zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (2,7-dit-butyl-9-fluorenyl) ) Zirconium dichloride and the like can be mentioned.

As the cocatalyst, the above-mentioned isotactic catalyst is used.
As a catalyst component capable of producing a α-olefin
The same co-catalyst used can be used. Isota
It is possible to produce a cutic poly-α-olefin.
The catalyst component and syndiotactic poly-α-olefin
The proportion of catalyst components that can be produced depends on the catalyst
The molar ratio of the transition metal compound in the components is 1000: 1 to 1: 1.
It is 1000, preferably 100: 1 to 1: 100.
The amount of co-catalyst depends on the type, but for example aluminum
In the case of nonsiloxane, it is 1 to 1 with respect to the metallocene compound.
000000 mol times, usually 10 to 10,000 mol times
It Transition Metal Compound and / or Assistance in the Present Invention
Even if the medium remains, SiO ₂, Al₂O₃, MgCl₂
Supported on a well-known carrier that supports Ziegler-type catalysts such as
You may use it. Further, the transition metallization in the present invention
Compounds and cocatalysts, especially transition metal compounds and aluminoxanes?
The catalyst consisting of
It can be used in the field. By doing so
Manufacturing polyolefins with less aluminoxane
It is also possible to do so. Organoaluminization used
As a compound, a compound represented by the general formula:

[0013]

Embedded image R ¹ _j Al (OR ² ) _k H _l X _m (wherein R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, R ¹ and R ² are the same as each other, and X is a halogen atom, O is an oxygen atom, H is a hydrogen atom, j is an integer from 1 to 3, k, l and m are integers from 0 to 2, and j + k + l + m = 3) can be used. Specific examples include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, diisobutyl aluminum hydride, and the like. Among them, triethylaluminum and triisobutylaluminum are preferably used. Although the amount used is not particularly limited, it is usually 1 to 1000 mol times with respect to the transition metal.

In the present invention, the molecular weight and molecular weight distribution of the produced polymer can be controlled by carrying out the polymerization at the polymerization temperature or in the presence of hydrogen. Further, it is possible to control the molecular weight and the molecular weight distribution of the produced polymer by mixing and using several kinds of catalysts. There are no particular restrictions on the polymerization method and polymerization conditions used in the method of the present invention, and known methods used in the polymerization of olefins can be used, including solvent polymerization methods using an inert hydrocarbon medium, or substantially inert hydrocarbons. A bulk polymerization method without a medium or a gas phase polymerization method can also be used, and the polymerization temperature is -100.
~ 200 ° C, polymerization pressure is normal pressure ~ 100 kg / cm
It is common to do in ² . Preferably -50 to 100
C, normal pressure to 50 kg / cm ² . Examples of the hydrocarbon medium used in the polymerization in the present invention include saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane, and cyclohexane, as well as aromatics such as benzene, toluene, and xylene. Hydrocarbons can also be used. As the α-olefin used in the polymerization, propylene, 1-
Butene, 4-methyl-1-pentene, 1-hexene, 1
Examples thereof include α-olefins having 3 to 25 carbon atoms such as octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene. In the present invention, it can be used not only for homopolymerization of α-olefins but also for producing copolymers of olefins having about 2 to 25 carbon atoms such as propylene and ethylene and propylene and 1-butene. Further, the method of the present invention can be applied to the copolymerization with a diene for the purpose of modifying the polyolefin. The diene compound used at that time is 1,4-hexadiene, 4-methyl-
1,4-hexadiene, ethylidene norbornene, dicyclopentadiene and the like can be mentioned.

What is important in the present invention is to polymerize the α-olefin by mixing and using the catalyst for syndiotactic poly-α-olefin and the catalyst for isotactic poly-α-olefin. By doing so, the syndiotactic poly-α-olefin and isotactic poly-are more evenly dispersed than those mechanically mixed.
It is possible to obtain a resin composition of α-olefin.
Such a composition is remarkably improved in processability and physical properties as compared with a plain resin having a syndiotactic or isotactic structure. For example, when the syndiotactic polypropylene alone is subjected to known molding processes such as T-die extrusion molding, injection molding, and granulation, there is a problem that the moldability is poor because the solidification speed is slow. Further, as is well known, a resin made of isotactic polypropylene alone has good processability, and it is possible to obtain a film, a sheet, a fiber, an injection molded article or the like having excellent mechanical properties. However, there is a defect that the molded product is inferior in transparency and flexibility. By using the method of the present invention, it is possible to obtain a poly-α-olefin resin having excellent moldability and physical properties, particularly a polypropylene resin, which overcomes the above-mentioned problems.

Since the poly-α-olefin obtained in the present invention has good processability as described above, known methods for molding polyolefins, such as T-die extrusion molding method, inflation molding method, and injection molding method. It can be easily and rapidly molded by a blow molding method, an injection stretch blow molding method, a melt spinning method, an extrusion spinning method, or the like. Further, in the present invention, by changing the composition ratio of the catalyst to be mixed, desired characteristics such as transparency, surface gloss,
A poly-α-olefin having mechanical properties can be obtained.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, the measuring method in an Example is as follows. Solidification time: The molten resin extruded in a strand shape at 240 ° C. using a 15 mmφ single screw extruder is cooled in water at 20 ° C., and the time until solidification is the solidification time (abbreviated as st).
And

Example 1 An autoclave having an internal volume of 1.5 dm ³ was placed in JP-A-2-2.
Diphenylmethylene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride 0.24 mg synthesized by the method described in JP 74703 and dimethylsilylene bis (2,4-dimethyl) synthesized by the method described in JP-A-3-12406. Cyclopentadienyl) zirconium dichloride 0.06 mg and methylaluminoxane (manufactured by Toso Akzo Co., Ltd.) as a co-catalyst on silica gel (manufactured by Fuji Silysia Chemical Ltd., surface area 480 m ² /
solid catalyst component 2 obtained by reacting with g)
20 cm ³ of a hexane slurry containing 1 mg and 43 mg of triisobutylaluminum was charged. Then liquid propylene 0.75 dm ³ and hydrogen 0.23 dm
³ (standard state) was charged, the temperature was raised to 60 ° C., and polymerization was performed for 1 hour. As a result, 136 g of polypropylene was obtained. IR analysis of this polymer revealed that it was a mixture of syndiotactic polypropylene and isotactic polypropylene. 135 ° C of the obtained polymer
Intrinsic viscosity (hereinafter abbreviated as [η]) measured with a tetralin solution of 1.63 / g, differential scanning calorimetry (DS
Melting point (Tm) measured in C) is 131 ° C., solidification time (s
t) was 45 seconds.

Example 2 Example 1 except 0.2 mg of diphenylmethylene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride and 0.1 mg of dimethylsilylenebis (2,4-dimethylcyclopentadienyl) zirconium dichloride. Polymerization of propylene was carried out in the same manner as in. As a result, 124 g of polypropylene was obtained. [Η] of this polymer was 1.38 / g, Tm was 126 ° C, 15
The solidification time (st) was 5 seconds at 10 seconds.

Comparative Example 1 Only 0.5 mg of diphenylmethylene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride was used as the metallocene catalyst component, and the hydrogen content was 0.92 d.
Polymerization of propylene was carried out in the same manner as in Example 1 except that m ³ (standard state) was used. As a result, 185 g of syndiotactic polypropylene was obtained. [Η] of this polymer was 1.67 / g, Tm was 132 ° C., and solidification time was measured. As a result, solidification did not occur even after 300 seconds.

[0021]

As described above, it can be seen that polypropylene having a high solidification rate is produced by the method of the present invention. By performing the method of the present invention, it is possible to produce a poly-α-olefin excellent in molding processability and physical properties,
It is extremely valuable industrially.

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Claims (5)

(57) [Claims] 1. At least one ¹³ C-NMR analysis
Isotactic pentad fraction measured by
Metallocene catalysts capable of producing isotactic poly-α-olefins having the above values and at least one syndio measured by ¹³ C-NMR analysis
Polymerizing an α-olefin in the presence of a metallocene catalyst capable of producing a syndiotactic poly-α-olefin having a tactic pentad fraction of 0.6 or more. A method for producing a poly-α-olefin, comprising: 2. A metallocene catalyst capable of producing an isotactic poly-α-olefin , wherein the transition metal is a dimetal.
The process according to claim 1, wherein comprising a metallocene compound and a cocatalyst is Rukoniumu atom. 3. A metallocene catalyst capable of producing a syndiotactic poly-α-olefin , wherein the transition metal is
The process according to claim 1, wherein comprising a metallocene compound and a cocatalyst zirconium atom. 4. A meta capable of producing a metallocene catalyst and syndiotactic polymethyl -α- olefins capable of producing isotactic poly -α- olefin
The method according to claim 1, wherein the proportion of the rosene catalyst is 1000: 1 to 1: 1000 in terms of the molar ratio of the transition metal compound in each catalyst component. 5. The method according to claim 1, wherein the poly-α-olefin is polypropylene.