JPH06287257A - Method for producing propylene-ethylene block copolymer - Google Patents

Abstract

(57) [Summary] [Structure] [A] Obtained by contacting with at least one metallocene-based transition metal compound, [B] clay, clay mineral or ion-exchange layered compound, and [C] organoaluminum compound. In the presence of a product, and optionally a catalyst comprising [D] an organoaluminum compound,
First, in the first step, a propylene homopolymer or a propylene-ethylene copolymer is produced by polymerizing propylene alone or propylene and ethylene under the condition that the propylene concentration in the gas phase is 90 mol% or more,
Propylene characterized in that propylene and ethylene are copolymerized in the second step in the presence of the catalyst and the polymer produced in the first step under the condition that the propylene concentration in the gas phase is less than 90 mol%. -Method for producing ethylene block copolymer. [Effect] Using the above catalyst of the present invention, a propylene-ethylene block copolymer having an excellent balance of rigidity and impact resistance can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a propylene-ethylene block copolymer. More specifically, it relates to a method for obtaining a propylene-ethylene block copolymer having an excellent balance of rigidity and impact resistance by using a specific catalyst.

[0002]

2. Description of the Prior Art Propylene homopolymers have excellent rigidity, but have the drawback of low impact resistance. As a method for improving this drawback, a method for producing a block copolymer by stepwise polymerizing propylene and ethylene is already known.

Further, as a catalyst system used in producing a propylene-ethylene block copolymer, a combination of a solid catalyst component containing titanium trichloride as a main component and an organic aluminum compound, magnesium, titanium, halogen, electron donating A combination of a carrier-supported catalyst component containing an organic compound as an essential component and an organoaluminum compound is known, and many patents relating to these catalyst systems have been filed.
However, most of these are still insufficient in the balance between rigidity and impact resistance, and there is room for improvement.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have proposed to provide a propylene-ethylene block copolymer having an excellent balance of rigidity and impact resistance as compared with conventionally known propylene-ethylene block copolymers. As a result of earnest studies,
The present invention has been reached. That is, the present invention is a product obtained by contacting [A] at least one metallocene-based transition metal compound, [B] clay, a clay mineral or an ion-exchange layered compound, and [C] an organoaluminum compound, And, if necessary, in the presence of a catalyst composed of [D] an organoaluminum compound, in the first step, propylene alone or propylene and ethylene are polymerized under the condition that the propylene concentration in the gas phase is 90 mol% or more. A propylene homopolymer or a propylene-ethylene copolymer is produced by the method described below, and propylene and ethylene are added in the presence of the catalyst and the polymer produced in the first step in the second step so that the propylene concentration in the gas phase is 90 mol. Of propylene-ethylene block copolymer, characterized in that it is copolymerized under the condition of less than 10% On.

The present invention will be described in detail below. The metallocene-based transition metal compound, which is the component [A] used in the catalyst of the present invention, is a cyclopentadienyl-based ligand that may be substituted, that is, a substituent may be bonded to form a condensed ring. It is an organometallic compound composed of a pentadienyl ring-containing ligand and a transition metal of Groups 4, 5, and 6 of the long periodic table.

The preferred metallocene-based transition metal compound is a compound represented by the following general formula [1] or [2].

[0007]

[Equation 1]

(However, in the formulas [1] and [2], each (CpR
² _n ) represents a cyclopentadienyl group or a substituted cyclopentadienyl group, which may be the same or different, and R ¹
Is the 14th element of the long periodic table of carbon, silicon, germanium, etc.
It is a covalent bond-linking group containing a group element, and each R ² may have the same or different hydrogen, halogen, a silicon-containing group, or a halogen-substituted group having 1 to 20 carbon atoms.
A hydrocarbon group, an alkoxy group, or an aryloxy group of R ^{2 in} which two R ² are adjacent to each other on the cyclopentadienyl ring.
When present at one carbon atom, they are bonded together to form C ₄
-C ₆ may form a ring. R ³ is hydrogen which may be the same or different, halogen, a silicon-containing group, a hydrocarbon group having 1 to 20 carbon atoms which may have a halogen substituent,
It is an alkoxy group, an aryloxy group, m is 0 or 1, each n is an integer such that n + m = 5, M is a metal of Groups 4, 5 and 6 of the long periodic table, and R ⁴ is R ^{5 −} is a neutral ligand that coordinates with M, and R ^{5 −} represents a counter anion capable of stabilizing the above metal cation.

In the above general formula [1] or [2], R ¹ is a covalent bond cross-linking group containing a Group 14 element of the long periodic table such as carbon, silicon and germanium, and is represented by a resin CpR ² n. And a cyclopentadienyl ring-containing group. Specifically, methylene group, alkylene group such as ethylene group, ethylidene group, propylidene group, isopropylidene group, phenylmethylidene group, alkylidene group such as diphenylmethylidene group, dimethylsilylene group, diethylsilylene group, dialkyl group Silicon-containing cross-linking groups such as propyl silylene group, diisopropyl silylene group, diphenyl silylene group, methyl ethyl silylene group, methylphenyl silylene group, methyl isopropyl silylene group, methyl-t-butyl silylene group, dimethylgermylene group, diethylgermylene group Group, dipropylgermylene group, diisopropylgermylene group, diphenylgermylene group, methylethylgermylene group, methylphenylgermylene group,
Examples thereof include a germanium-containing cross-linking group such as a methylisopropylgermylene group and a methyl-t-butylgermylene group, an alkylphosphine, an amine and the like. Of these, an alkylene group, an alkylidene group, and a silicon-containing bridging group are particularly preferably used.

Each CpR ² n is a cyclopentadienyl group or a substituted cyclopentadienyl group which may be the same or different. Here, R ² is hydrogen which may be the same or different, halogen such as fluorine, chlorine, bromine and iodine,
Silicon-containing groups such as trimethylsilyl, triethylsilyl and triphenylsilyl groups, methyl, ethyl, propyl, butyl, isobutyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, phenyl,
A hydrocarbon group having 1 to 20 carbon atoms which may have a halogen group such as chloromethyl and chloroethyl groups, an alkoxy group such as methoxy, ethoxy, propoxy and butoxy groups, or a phenoxy, methylphenoxy and pentamethylphenoxy group. And aryloxy groups.

When two R ^2's are present at two adjacent carbon atoms of the cyclopentadienyl ring,
They may combine with each other to form a C ₄ -C ₆ ring to form an indenyl, tetrahydroindenyl, fluorenyl, octahydrofluorenyl group or the like. Of these, particularly preferable as R ² is hydrogen, a methyl group, and a hydrocarbon group in which ^two R ² are bonded to each other to form an indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl group. .

R ³ may be the same or different, hydrogen, halogen such as fluorine, chlorine, bromine and iodine, a silicon-containing group such as trimethylsilyl, triethylsilyl and triphenylsilyl group, methyl, ethyl, propyl, butyl and isobutyl. , Pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, phenyl, chloromethyl, chloroethyl, and other hydrocarbon groups having 1 to 20 carbon atoms, which may have a halogen group, methoxy, ethoxy, propoxy, butoxy. It is an alkoxy group such as a group or an aryloxy group such as a phenoxy group, a methylphenoxy group and a pentamethylphenoxy group, and particularly preferably a hydrogen group, a chlorine group and a methyl group.

M is two cyclopentadienyl rings R ¹
It is 0 when they are not combined with and is 1 when they are combined. Each n is 4 when m is 1 and 5 when m is 0. M is a metal of Groups 4, 5 and 6 of the long periodic table such as titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten,
Particularly, titanium, zirconium and hafnium are preferable.

R ⁴ is a neutral ligand that coordinates to M such as tetrahydrofuran, and R ^5- is the above-mentioned tetraphenyl borate, tetra (p-tolyl) borate, carbadodecaborate, dicarbaundecaborate and the like. General formula [2]
It shows a counter anion capable of stabilizing the metal cations therein. The catalyst of the present invention is an isotactic polymer,
Any of the syndiotactic polymers can be made.

In the metallocene-based transition metal compound, specifically, when zirconium is taken as an example, those corresponding to the formula [1] include isopropylidene-bis (indenyl) zirconium dichloride and isopropylidene-bis ( Indenyl) zirconium dimethyl, isopropylidene-bis (indenyl) zirconium dihydride, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dimethyl, dimethylsilyl (cyclopenta) Dienyl) (fluorenyl) zirconium dimethyl, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dihydride, methylene-bis (cyclopentadienyl) zirconium di Lolide, methylene-bis (tetramethylcyclopentadienyl) zirconium dichloride, ethylene-bis (cyclopentadienyl) zirconium dichloride, ethylene-bis (tetramethylcyclopentadienyl) zirconium dichloride, isopropylidene-bis (cyclopentadiene) (Enyl) zirconium dichloride, dimethylsilyl-bis (cyclopentadienyl) zirconium dichloride, methylene-bis (cyclopentadienyl) zirconium dimethyl, methylene-bis (tetramethylcyclopentadienyl) zirconium dimethyl, ethylene-bis (cyclopenta) Dienyl) zirconium dimethyl, isopropylidene-bis (cyclopentadienyl) zirconium dimethyl, dimethylsilyl-bis (cyclopentadiene Nyl) zirconium dimethyl, methylene-bis (cyclopentadienyl) zirconium dihydride, ethylene-bis (cyclopentadienyl) zirconium dihydride, isopropylidene-bis (cyclopentadienyl) zirconium dihydride, dimethylsilyl -Bis (cyclopentadienyl) zirconium dihydride and the like.

Further, those corresponding to the general formula [2] include isopropylidene-bis (indenyl) zirconium (chloride) (tetraphenylborate) tetrahydrofuran complex, isopropylidene-bis (indenyl) zirconium (methyl) (tetraphenyl) Borate) tetrahydrofuran complex, isopropylidene-bis (indenyl) zirconium (hydride) (tetraphenylborate) tetrahydrofuran complex, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium (chloride) (tetraphenylborate) tetrahydrofuran complex, isopropylpyridene (cyclo) Pentadienyl) (fluorenyl) zirconium (chloride) (tetraphenylborate) tetrahydrofuran complex, isopropylidene ( Clopentadienyl) (fluorenyl) zirconium (methyl) (tetraphenylborate) tetrahydrofuran complex, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium (hydride) (tetraphenylborate) tetrahydrofuran complex, methylene-bis (cyclopentadiene) (Enyl) zirconium (chloride) (tetraphenylborate) tetrahydrofuran complex, ethylene-bis (cyclopentadienyl) zirconium (chloride) (tetraphenylborate) tetrahydrofuran complex, isopropylidene-bis (cyclopentadienyl) zirconium (chloride) ( Tetraphenylborate) tetrahydrofuran complex, dimethylsilyl-bis (cyclopentadienyl) zirconium (chloride) (teto Phenylborate) tetrahydrofuran complex, methylene-bis (cyclopentadienyl) zirconium (methyl) (tetraphenylborate) tetrahydrofuran complex, ethylene-bis (cyclopentadienyl) zirconium (methyl) (tetraphenylborate) tetrahydrofuran complex, isopropylidene -Bis (cyclopentadienyl) zirconium (methyl) (tetraphenylborate) tetrahydrofuran complex, dimethylsilyl-bis (cyclopentadienyl) zirconium (methyl) (tetraphenylborate) tetrahydrofuran complex, methylene-bis (cyclopentadienyl) ) Zirconium (hydride) (tetraphenylborate) tetrahydrofuran complex, ethylene-bis (cyclopentadienyl) zirconium (hydrido) De) (tetraphenylborate) tetrahydrofuran complex, isopropylidene-bis (cyclopentadienyl) zirconium (hydrido) (tetraphenylborate) tetrahydrofuran complex, dimethylsilyl-bis (cyclopentadienyl) zirconium (hydrido) (tetraphenylborate) ) Tetrahydrofuran complex and the like.

The same compounds as described above can be used for other Group 4, 5 and 6 metal compounds such as titanium compounds and hafnium compounds. Further, a mixture of these compounds may be used. Furthermore, it can be used together with a known solid catalyst containing titanium trichloride as a main component and a carrier-supported catalyst containing magnesium, titanium and halogen as essential components.

In the present invention, as the component [B], clay, clay minerals or ion-exchange layered compounds are used.
Clay is usually composed mainly of clay minerals. The ion-exchangeable layered compound is a compound having a crystal structure in which planes formed by ionic bonds and the like are stacked in parallel with each other with weak bonding forces, and the ions contained therein are exchangeable. Most clay minerals are ion-exchangeable layered compounds. Further, these clays, clay minerals, and ion-exchange layered compounds are not limited to naturally-occurring ones, but may be artificially synthesized ones.

As the component [B], clay, clay minerals, hexagonal closest packing type, antimony type, CdCl ₂
Examples thereof include ionic crystalline compounds having a layered crystal structure such as C type and CdI ₂ type. Specific examples of the clay or clay mineral of the component [B] include kaolin, bentonite, kibushi clay, gyrome clay, allophane, hisingel stone, pyrophyllite, talc, pummo group, montmorillonite group, vermiculite, ryokdeite group, palygorskite. , Kaolinite, nacrite, dickite, halloysite and the like.

Specific examples of the ion-exchange layered compound include α-Zr (HAsO ₄ ) ₂ .H ₂ O and α-Zr (H
_{PO 4) 2, α-Zr} (KPO 4) 2 · 3H 2 O, α-
Ti (HPO ₄ ) ₂ , α-Ti (HAsO ₄ ) ₂ · H ₂
O, α-Sn (HPO ₄ ) ₂ · H ₂ O, γ-Zr (HP
O ₄ ) ₂ , γ-Ti (HPO ₄ ) ₂ , γ-Ti (NH ₄
Examples thereof include crystalline acidic salts of polyvalent metals such as PO ₄ ) ₂ · H ₂ O.

As the component (B), those having a pore volume of 20 cc or more in radius measured by mercury porosimetry of 0.1 cc / g or more, particularly 0.3 to 5 cc / g are preferable. Here, the pore volume is measured by a mercury porosimetry method using a mercury porosimeter in the pore radius range of 20 to 30000Å. In this embodiment, “Auto by Shimadzu Corporation” is used.
It was measured using a "Pore 9200". In addition,
As the component [B], the pore volume with a radius of 20 Å or more is 0.1
When a compound having a cc / g or less is used, it tends to be difficult to obtain high polymerization activity.

It is also preferable that the component [B] is chemically treated. Here, as the chemical treatment, both surface treatment for removing impurities adhering to the surface and treatment for affecting the crystal structure of clay can be used. In particular,
Examples include acid treatment, alkali treatment, salt treatment and organic substance treatment. The acid treatment not only removes impurities on the surface but also increases the surface area by eluting cations such as Al, Fe and Mg in the crystal structure. Alkali treatment destroys the crystal structure of clay, resulting in a change in clay structure. In the salt treatment and the organic substance treatment, an ionic complex, a molecular complex, an organic derivative, etc. are formed to change the surface area and the interlayer distance.

By utilizing the ion exchange property and substituting the exchangeable ions between the layers with another large bulky ion, it is possible to obtain a layered substance in which the layers are expanded. That is, bulky ions play a pillar-like role for supporting the layered structure, and are called pillars. Introducing another substance between layers of layered substances is called intercalation.

The guest compound to be intercalated is a cationic inorganic compound such as TiCl ₄ , ZrCl ₄ , Ti (OR) ₄ , Zr (OR) ₄ , PO (OR).
₃ , a metal alcoholate such as B (OR) ₃ [R is alkyl, aryl, etc.], [Al ₁₃ O ₄ (OH) ₂₄ ] ⁷⁺ , [Z
r ₄ (OH) ₁₄ ] ²⁺ , [Fe ₃ O (OCOCH ₃ ) ₆ ]
^And metal hydroxide ions such as ⁺ . These compounds may be used alone or in combination of two or more. Further, when intercalating these compounds, Si (OR) ₄ , Al (OR) ₃ , Ge
A polymer obtained by hydrolyzing a metal alcoholate such as (OR) ₄ or the like, a colloidal inorganic compound such as SiO ₂ or the like may be allowed to coexist. Examples of pillars include oxides produced by intercalating the above hydroxide ions between layers and then heating and dehydrating.

The component [B] may be used as it is, or may be used after newly adsorbing and adsorbing water or after heat dehydration treatment. Further, they may be used alone or in combination of two or more of the above solids. As the component [B], preferred is clay or clay mineral, and most preferred is
It is montmorillonite.

Examples of the organoaluminum compound used as the component [C] in the present invention include trialkylaluminum such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, diethylaluminum monochloride, diethylaluminum methoxide. And the like, halogen- or alkoxy-containing alkylaluminum, aluminoxane such as methylaluminoxane, and the like, among which trialkylaluminum is particularly preferable.

The contact method for obtaining the polymerization catalyst from the components [A], [B] and [C] is described in [B]
When the component is clay or clay mineral, the molar ratio of the transition metal in the component [A] to the hydroxyl group of the clay or clay mineral and the aluminum in the [C] organoaluminum compound is 1: 0.1 to 100000: 0. 1-100,000
00, especially from 1: 0.5 to 10000: 0.
The catalytic reaction is preferably carried out at 5 to 1,000,000.

When the component [B] is other than clay or clay mineral, the weight ratio of the transition metal in the component [A] to aluminum in the component [C] is 1 g of the component [B]. 0.00001-1 (g): 0.001-100
It is preferable to bring them into contact so as to give (g). Contact with pentane, hexane, heptane, in an inert gas such as nitrogen,
It may be carried out in an inert hydrocarbon solvent such as toluene or xylene. The contact temperature is between -20 ° C and the boiling point of the solvent, preferably room temperature to the boiling point of the solvent.

The order of contacting the respective components of the catalyst is not particularly limited, but they can be contacted in the following contacting order. After the component [A] and the component [B] are contacted with each other, the component [C] is added. The component [A] and the component [C] are brought into contact with each other, and then the component [B] is added. After the component [B] and the component [C] are contacted with each other, the component [A] is added.

In addition, the three components may be contacted at the same time. During or after the contact of each component of the catalyst, a polymer such as polyethylene or polypropylene, or a solid of an inorganic oxide such as silica or alumina may coexist or contact. The olefin can be prepolymerized in the presence of the above-mentioned components [A], [B] and [C] and, if necessary, the organoaluminum compound [D]. Prepolymerization temperature is −
The temperature is 50 to 100 ° C., and the prepolymerization time is 0.1 to 100 hours, preferably 0.1 to 50 hours.

As the organoaluminum compound [D] which is optionally used in the prepolymerization, the same compounds as the component [C] can be mentioned. The amount of the organoaluminum compound used at this time is such that the molar ratio of aluminum in the transition metal [D] component in the catalyst component [A] is 1.0: to 10.
Is chosen to be 000. The olefin used in the prepolymerization is preferably the olefin used in the polymerization, but other olefins may be used. Also, olefins can be mixed and used.

The amount of polymer produced by the prepolymerization is [B]
0.001 to 1000 g, preferably 0.01 to 300 g, and more preferably 0.1 to 300 g per 1 g of the component
Is the range. Solvents used for producing the olefin polymerization catalyst according to the present invention, butane, pentane, hexane, heptane, octane, cyclohexane, toluene,
Xylene or the like, or a mixture thereof or the like.

The catalyst thus obtained may be used without washing, or may be used after washing. When carrying out propylene-ethylene block copolymerization using the above-mentioned olefin polymerization catalyst, the organoaluminum compound [D] used as required includes the same compounds as the above-mentioned component [C]. The amount of the organoaluminum compound [D] used in this case is selected so that the molar ratio of the transition metal in the catalyst component [A] to the aluminum in the organoaluminum compound is 1: 0 to 10,000.

Propylene-ethylene block copolymerization is 2
The polymerization reaction is carried out in stages, but in the presence or absence of an inert hydrocarbon such as propane, butane, hexane, heptane, or toluene, or a solvent such as liquefied α-olefin. First, in the first stage, the catalyst obtained previously and, if necessary, an organoaluminum compound are used,
Homopolymerization of propylene or copolymerization of propylene and ethylene is carried out under the condition that the propylene concentration in the gas phase (concentration of propylene relative to the sum of propylene and ethylene) is 90 mol% or more (hereinafter, referred to simply as propylene homopolymerization). Abbreviated.). Usually, the amount of propylene homopolymer is
The polymerization temperature and time are selected so as to be 50 to 95% of the total polymer production. Polymerization temperature is usually -20 to 150
℃, preferably selected from the range of 0 ~ 100 ℃. Hydrogen is preferred as the molecular weight regulator.

Next, in the second step, propylene and ethylene are copolymerized in the presence of the propylene homopolymer produced in the first step. Here, an organoaluminum compound may be newly added. The propylene concentration in the gas phase is 90
It may be less than mol%, but is preferably 30 to 85 mol%. Usually, the polymerization temperature and the polymerization time are selected such that the amount of the propylene-ethylene copolymer is 5 to 50% by weight based on the total amount of the polymer produced. Polymerization temperature is usually 0-100
℃, preferably selected from the range of 20 ~ 80 ℃. Hydrogen is preferred as the molecular weight regulator.

After the first and second stages of polymerization, and subsequently, after the third stage, copolymerization of propylene and ethylene, ethylene alone or ethylene and a small amount of other α-.
You may copolymerize with an olefin. Further, various polymers such as polyethylene, polypropylene, polybutene, poly-3-methylbutene-1,
Polyolefin such as poly-4-methylpentene-1 may be melt mixed or mixed in a solution state.

[0037]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited by these examples without departing from the gist thereof. In the examples, the isotactic index (indicated as II) is the residual amount (% by weight) when extracted for 6 hours with boiling n-hexane in a modified Soxhlet extractor. Melt flow index (shown as MFI, unit: g / 10 min) was measured according to ASTM-D-1238.

The first yield strength YS (kg / cm ² ) is AS
Based on TM-D-638, it was determined by a tensile test of an injection-molded dumbbell piece. Flexural modulus FM (kg / cm
² ) was measured according to ASTM-D-790. Izod impact strength (kg-cm / cm) is ASTM-D-2
According to No. 56, the measurement was performed on the injection-molded piece with a notch. The physical properties of these materials were measured at 23 ° C.

Example 1 (1) Synthesis of dimethylsilylbis (methylcyclopentadienyl) hafnium dichloride All reactions were carried out under an inert gas atmosphere, and the reaction solvent used was previously dried. Dimethylbis (methylcyclopentadienyl) in a 200 ml round bottom flask
After dissolving 4.4 g (20 mmol) of silane in 67 ml of tetrahydrofuran, 1.6 M of n-butyllithium was added.
28 ml of a hexane solution was slowly added dropwise under ice cooling.
After stirring at room temperature for 2 hours, a yellow transparent liquid (Li ₂ [Me ₂
Was obtained _{Si (Me-C 5 H 3} ) 2 ]).

HfCl ₄ in a 500 ml round bottom flask
6.4 g (20 mmol) was cooled to −78 ° C., and 267 ml of tetrahydrofuran was added. Then, the yellow transparent solution was slowly added dropwise at -78 ° C. After the dropping, the temperature was gradually raised, the mixture was stirred at room temperature for 17.5 hours, and then heated under reflux for 1 hour.
After cooling, the solvent was distilled off from the yellow-orange solution containing white precipitate,
Under ice cooling, 267 ml of methylene chloride and then 133 parts of dilute hydrochloric acid
After adding ml and separating the layers, the methylene chloride layer was dried over anhydrous sodium sulfate. Methylene chloride was distilled off, pentane was added, the insoluble solid was filtered, and the yellow filtrate was cooled to give yellowish white crystals.

(2) Synthesis of catalyst components A commercially available montmorillonite (manufactured by Aldrich, Montmorillonit was placed in a 300 ml round bottom flask.
e K10; 17 g of a pore volume of 1.004 cc / g having a radius of 20 Å or more measured by mercury porosimetry was collected, and the inside of the flask was replaced with nitrogen, and 50 ml of toluene was added to form a slurry. Separately, trimethylaluminum 7.21
g was dissolved in 50 ml of toluene. While stirring the montmorillonite slurry vigorously, the trimethylaluminum solution was slowly added dropwise thereto at room temperature. It generated heat with the generation of gas. If necessary, stir 2 while cooling with ice water.
Continued for hours to obtain a gray-green slurry.

(3) Propylene-Ethylene Block Copolymerization 2.2 mg of dimethylsilylbis (methylcyclopentadienyl) hafnium dichloride at room temperature under nitrogen atmosphere and with 0.01 ml of a toluene solution of 0.0179 M trimethylaluminum for 30 minutes. 2.6 ml of the catalyst component slurry prepared by the above (2) after pre-contact
Contacted for 20 minutes.

The catalyst component contact mixture was added at room temperature under a nitrogen stream to a 2 liter induction-stirring autoclave, which was replaced with purified nitrogen and contained an anchor type stirring blade. Furthermore, 700 g of liquefied propylene was charged at room temperature. Then 3
The temperature was raised to 0 ° C. to start the first stage polymerization. 2 at 30 ° C
After carrying out the polymerization reaction for a period of time, unreacted propylene was purged to complete the polymerization reaction in the first stage. Then, the temperature was raised to 50 ° C. with stirring and mixing, and after the temperature was raised, propylene gas and ethylene gas were charged so that the total polymerization pressure was 10 kg / cm ^2, to start the second stage polymerization. Total polymerization pressure is 1
While supplying a mixed gas of propylene and ethylene so as to be constant at 0 kg / cm ² gauge pressure, a polymerization reaction was carried out at 50 ° C. for 0.3 hours. Here, the propylene / (propylene + ethylene) ratio was 51.4 mol% on average.

After 0.3 hours, propylene and ethylene were purged to obtain a propylene-ethylene block copolymer. BH as an additive to the powder obtained as described above
T (2,6-di-t-butyl-p-cresol) was adjusted to 0.
1% by weight, 0.1% by weight of Irganox 1010 (manufactured by Ciba-Geigy), 0.1 of calcium stearate
21% using a single screw extruder with an inner diameter of 20 mm.
Kneading was performed at 0 ° C. Next, injection-molded pieces were prepared and various physical properties were measured. As a result, the first yield strength YS
Is 300 kg / cm ² , and the flexural modulus FM is 14,500.
kg / cm ² and Izod impact strength is 35.0 k
The balance between g-cm / cm and rigidity-impact resistance was good. Table 1 shows the polymerization conditions and measurement results of various physical properties.

[0045]

[Table 1]

Comparative Example 1 (1) Manufacture of solid catalyst component In a 500 ml flask equipped with a stirrer and a thermometer and having purified N ₂ substituted, 10 g of commercially available Mg (OC ₂ H ₅ ) ₂ and Ti (O
14.9 g of C ₄ H ₉ ) ₄ and 9.2 g of tetraethoxysilane were mixed, and the temperature was raised to 135 ° C. with stirring. Thirteen
Toluene solution 50 of 16.4 g of phenol at 5 ° C
ml was added dropwise over 30 minutes. After dropping, the mixture was reacted at 135 ° C. for 1 hour to obtain a yellow-orange slurry-like reaction product.

125 ml of purified toluene was added to this product, which was then cooled to -20 ° C and TiCl 2 at -20 ° C.
The ₄ 50g was added. After the addition, the temperature was gradually raised, 50 g of TiCl ₄ was added at 50 ° C., and the temperature was further raised. 110
2.6 g of ethyl benzoate was added at 0 ° C, and the mixture was kept at the same temperature for 1 hour. Then, the solid catalyst component was washed 3 times with 200 ml of purified toluene to obtain 12.4 g of a solid catalyst component. This thing Ti
When the content was analyzed, it was 3.9% by weight.

[0048] (2) before 1l induction stirring type autoclave was sufficiently substituted with polymerization purified N _2, purified N ₂ seal under normal hexane 50 at room temperature
ml, 1.2 mmol of trinormalpropylaluminum and 1 g of the solid catalyst component obtained in Example 1 (1) were added. Thereafter, propylene gas was passed through at 25 ° C. for 1 minute to obtain a prepolymerization catalyst component. The obtained prepolymerized catalyst component contained 1.5 g of polymer per 1 g of the solid catalyst component.

(3) Propylene-Ethylene Block Copolymerization A 2-liter induction stirring autoclave equipped with an anchor type stirring blade was sufficiently replaced with purified N ₂ . Then, after substituting with propylene gas, 1.0 mmol of triethylaluminum and 0.3 mmol of methyl toluate were charged. Liquefied propylene 70 after charging 1.1 kg / cm ^{2 of} hydrogen gas
0 g was charged. Thereafter, the temperature was raised to 70 ° C., and the temperature was raised.
The prepolymerization catalyst component obtained in (2) was injected as a solid catalyst component in an amount of 15 mg to initiate the first stage polymerization. After carrying out the polymerization reaction at 70 ° C. for 1 hour, propylene and hydrogen were purged to terminate the polymerization reaction in the first stage. Then, the temperature was raised to 70 ° C. with stirring and mixing, and after the temperature was raised, the total polymerization pressure of hydrogen gas, propylene gas and ethylene gas was 10 kg / c
It was charged so as to have a m ² gauge pressure to start the second stage polymerization. The polymerization reaction was carried out at 70 ° C. for 0.6 hours while supplying a mixed gas of propylene and ethylene so that the total polymerization pressure was constant at 10 kg / cm ² gauge pressure. Here propylene / propylene + ethylene ratio is an average 62.9 mol%, H ₂ / propylene + ethylene ratio averaged 0.33 mol%.

After 0.6 hours, propylene, ethylene and hydrogen were purged to obtain a white powdery propylene-ethylene block copolymer. First yield strength of this product YS
Is 248 kg / cm ² , and the flexural modulus FM is 12,900.
kg / cm ² , Izod impact strength is 13.8 kg-c
It was m / cm.

[0051]

EFFECTS OF THE INVENTION According to the specific catalyst of the present invention, it is possible to obtain a propylene-ethylene block copolymer having an excellent balance of rigidity and impact resistance, as is clear from the comparison of Examples and Comparative Examples.

[Brief description of drawings]

FIG. 1 is a flow chart showing one embodiment of a preparation process and a polymerization process of a catalyst used in the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Kumazaki 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Hideaki Tanaka 1000-3, Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Ryokasei Co., Ltd.

Claims (1)

[Claims] 1. A product obtained by contacting [A] at least one metallocene-based transition metal compound, [B] clay, a clay mineral or an ion-exchange layered compound, and [C] an organoaluminum compound, And optionally in the presence of a catalyst comprising [D] an organoaluminum compound,
First, in the first step, a propylene homopolymer or a propylene-ethylene copolymer is produced by polymerizing propylene alone or propylene and ethylene under the condition that the propylene concentration in the gas phase is 90 mol% or more,
Propylene characterized in that propylene and ethylene are copolymerized in the second step in the presence of the catalyst and the polymer produced in the first step under the condition that the propylene concentration in the gas phase is less than 90 mol%. -Method for producing ethylene block copolymer.