JP2781244B2 - Method for producing ethylene polymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an ethylene-based polymer composition, and more particularly to a method for producing an ethylene-based polymer composition by a multistage polymerization method, and more particularly, to a method for producing a polymer having a melting property. The present invention relates to a method for producing an ethylene polymer composition which is excellent and has good processability during melt molding.

Technical Background of the Invention In recent years, as a new Ziegler-type olefin polymerization catalyst, a method for producing an olefin polymer using a catalyst comprising a zirconocene compound and an aluminoxane has been disclosed in
Nos. -19309, 60-35007 and 61-221208, and according to these publications, it is possible to obtain an ethylene polymer having a narrow molecular weight distribution and a narrow composition distribution and excellent transparency. Has been reported to be However, the polymer obtained using the olefin polymerization catalyst as described above has a narrow molecular weight distribution and poor processability,
For some applications, improved melting properties are desired.

For the purpose of improving these, it is possible to use two or more metallocene compounds in combination with JP-A-60-35006 and JP-A-60-35008.
Japanese Patent Application Laid-Open No. 63-501369 discloses a combination use of a metallocene compound and a non-metalonene compound.
However, it has not been sufficiently satisfied.

Object of the Invention The present invention has been made in view of the prior art as described above, and it is an object of the present invention to provide a method for producing an ethylene-based polymer composition having excellent melting properties while maintaining original excellent properties. The purpose is.

SUMMARY OF THE INVENTION A process for producing an ethylene-based polymer composition according to the present invention is directed to a catalyst for olefin polymerization comprising a transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton and an organoaluminum oxy compound [B]. And the polymerization step (a): ethylene or ethylene and another α-
Polymerization or copolymerization with olefin, density 0.88g /
cm ³ or more, and step intrinsic viscosity [eta] form an ethylene-based polymer [I] is a 0.3~3dl / g, and the polymerization step (b): copolymerizing ethylene and other α- olefins The density is not higher than that of the ethylene polymer [I], and the intrinsic viscosity [η] of the ethylene polymer [I] is at least 1.5 times the intrinsic viscosity [η] and 1 to 10 dl. After performing the polymerization step (a), a polymerization step (b) is performed in the presence of the product, or a polymerization step (b) is carried out in the presence of the product. After performing the step (b), the polymerization step (a) is performed in the presence of the product, and the polymerization amount in both steps is adjusted based on 100 parts by weight of the ethylene-based polymer [I]. II] is conducted such that the ratio of 10 to 1000 parts by weight, density be 0.86~0.94g / cm ³ One intrinsic viscosity [eta] is characterized by obtaining the ethylene polymer composition is 1~6dl / g.

According to the method for producing an ethylene-based polymer composition according to the present invention, an ethylene-based polymer having excellent melting properties can be obtained.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for producing the ethylene polymer composition according to the present invention will be specifically described.

In the method for producing an ethylene-based polymer composition according to the present invention, a transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton and an organic aluminum oxy [B]
An olefin polymerization catalyst comprising:

FIG. 1 (a) and FIG. 1 (b) are explanatory diagrams showing the steps of producing the ethylene polymer composition according to the present invention.

First, the transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton will be described.

A transition metal compound containing a ligand having a cycloalkadienyl skeleton is represented by the formula ML _X (where M is a transition metal, L is a ligand that coordinates to the transition metal, and at least one L Is a ligand having a cycloalkadienyl skeleton, and when at least two or more ligands having a cycloalkadienyl skeleton are included, the ligand having at least two cycloalkadienyl skeletons is an alkylene L may be bonded via a substituted alkylene group, a silylene group or a substituted silylene group, and L other than a ligand having a cycloalkadienyl skeleton is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group. Group, halogen or hydrogen, and x is the valence of the transition metal.)

In the above formula, M is a transition metal, and specifically, is preferably zirconium, titanium or hafnium, or chromium or vanadium, of which zirconium and hafnium are particularly preferable.

As the ligand having a cycloalkadienyl skeleton,
For example, alkyl-substituted cyclopentane such as cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadienyl group, n-butylcyclopentadienyl group, dimethylcyclopentadienyl group and pentamethylcyclopentadienyl group Examples thereof include a dienyl group, an indenyl group, and a fluorenyl group.

The ligand having a cycloalkadienyl skeleton as described above may be coordinated to two or more transition metals. In this case, the ligand having at least two cycloalkadienyl skeletons is They may be bonded via an alkylene group, a substituted alkylene group, a silylene group, or a substituted silylene group.

Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. Examples of the substituted alkylene group include an isopropylidene group and a tetramethylethylene group.The substituted silylene group includes a dimethylsilylene group. , Ethylmethylsilylene group, diphenylsilylene group and the like.

The ligand other than the ligand having a cycloalkadienyl skeleton is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a halogen or hydrogen.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group. Specifically, examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. , An isopropyl group, a butyl group, and the like.Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.Examples of the aryl group include a phenyl group and a tolyl group.Examples of the aralkyl group include a benzyl group, A neofil group is exemplified.

Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group. Examples of the aryloxy group include a phenoxy group.

Examples of the halogen include fluorine, chlorine, bromine, and iodine.

Hereinafter, specific examples of the transition metal compound containing a ligand having a cycloalkadienyl skeleton in which M is zirconium will be described.

Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium monobromide monohydride, bis (cyclopentadienyl) methylzirconium hydride, bis (cyclopentadienyl) ethylzirconium hydride, bis ( Cyclopentadienyl) phenyl zirconium hydride, bis (cyclopentadienyl) benzyl zirconium hydride, bis (cyclopentadienyl) neopentyl zirconium hydride, bis (methylcyclopentadienyl) zirconium monochloride hydride, bis (indenyl) zirconium Monochloride monohydride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) ) Zirconium dibromide, bis (cyclopentadienyl) methyl zirconium monochloride, bis (cyclopentadienyl) ethyl zirconium monochloride, bis (cyclopentadienyl) cyclohexyl zirconium monochloride, bis (cyclopentadienyl) phenyl zirconium Monochloride, bis (cyclopentadienyl) benzylzirconium monochloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride bis (Indenyl) zirconium dichloride, bis (indenyl) zirconium dibromide, bis (cyclopentadienyl) zirconium dimethyl, (Lopentadienyl) zirconium diphenyl, bis (cyclopentadienyl) zirconium dibenzyl, bis (cyclopentadienyl) zirconium methoxychloride, bis (cyclopentadienyl) zirconium ethoxycyclolide, bis (methylcyclopentadienyl) zirconium ethoxycyclolide Bis (cyclopentadienyl) zirconium phenoxycyclolide, bis (fluorenyl) zirconium dichloride, ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) diethylzirconium, ethylenebis (indenyl) diphenylzirconium monochloride, ethylenebis (indenyl) methyl Zirconium monochloride, ethylene bis (indenyl) ethyl zirconium monochloride, ethi Bis (indenyl) methylzirconium monobromide, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) zirconium dibromide, ethylenebis (4,5,6,7-tetrahydro-1-indenyl) dimethylzirconium, ethylenebis (4 , 5,6,7-Tetrahydro-1-indenyl) methylzirconium monochloride, ethylenebis (4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride, ethylenebis (4,5,6,7-tetrahydro -1-indenyl) zirconium dibromide, ethylenebis (4-methyl-1-indenyl) zirconium dichloride, ethylenebis (5-methyl-1-indenyl) zirconium dichloride, ethylenebis (6-methyl-1-indenyl) zirconium dichloride , Ethi Bis (7-methyl-1-indenyl) zirconium dichloride, ethylenebis (5-methoxy-1-indenyl) zirconium dichloride, ethylenebis (2,3-dimethyl-1-indenyl) zirconium dichloride, ethylenebis (4,7- Dimethyl-1-indenyl) zirconium dichloride, ethylenebis (4,7-dimethoxy-1-indenyl)
Zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, isopropylidenebis (indenyl) zirconium dichloride, dimethylsilylenebis (cyclopentadienyl) zirconium dichloride, dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride, Dimethylsilylenebis (indenyl) zirconium dichloride.

Further, in the above zirconium compound, a transition metal compound in which zirconium metal is replaced with titanium metal, hafnium metal or vanadium metal can also be used.

Next, the organic aluminum oxy compound [B] will be described.

The organic aluminum oxy compound [B] may be a conventionally known aluminum oxane, or may be a benzene-insoluble organic aluminum oxy compound discovered by the present inventors.

The aluminoxane as described above can be produced, for example, by the following method.

(1) Compounds containing water of adsorption or salts containing water of crystallization, such as hydrated magnesium chloride, hydrated copper sulfate, hydrated aluminum sulfate, hydrated nickel sulfate, hydrated cerous chloride A method of adding an organoaluminum compound such as a trialkylaluminum to a suspension of a hydrocarbon medium of Example 1 and reacting the suspension to recover a hydrocarbon solution.

(2) A method in which an organic aluminum compound such as trialkylaluminum is directly allowed to act on water, ice or steam in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran to recover as a hydrocarbon solution.

The aluminoxane may contain a small amount of an organic metal component. Alternatively, the solvent or unreacted organoaluminum compound may be removed from the recovered solution of aluminoxane by distillation, and then redissolved in the solvent.

Specific examples of the organoaluminum compound used when producing the solution of aluminoxane include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, and trisec-. Trialkyl aluminum such as butyl aluminum, tri-tert-butyl aluminum, tripentyl aluminum, trihexyl aluminum, trioctyl aluminum, tridecyl aluminum, tricyclohexyl aluminum, tricyclooctyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diethyl aluminum bromide ,
Dialkyl aluminum halides such as diisobutyl aluminum chloride, diethyl aluminum hydride, dialkyl aluminum hydrides such as diisobutyl aluminum hydride, dimethyl aluminum methoxide, dialkyl aluminum alkoxides such as diethyl aluminum ethoxide, and dialkyl aluminum aryloxides such as diethyl aluminum phenoxide. Can be

Of these, trialkyl aluminum is particularly preferred.

Also, iso organoaluminum compound represented by the general formula _{(i-C 4 H 9)} X Al y (C 5 H 10) Z (x, y, z are each a positive number, which is a z ≧ 2x) represented by Prenyl aluminum can also be used.

The above-mentioned organoaluminum compounds are used alone or in combination.

Solvents used in the solution of aluminoxane include:
Aromatic hydrocarbons such as benzene, toluene, xylene, cumene, cymene, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane, octadecane, cyclopentane, cyclohexane, cyclooctane, methylcyclopentane, etc. And petroleum fractions such as gasoline, kerosene and light oil, and ethers such as ethyl ether and tetrahydrofuran. Among these solvents, aromatic hydrocarbons are particularly preferred.

The benzene-insoluble organoaluminum oxy compound used in the present invention has an Al component soluble in benzene at 60 ° C. of not more than 10%, preferably not more than 5%, particularly preferably not more than 2% in terms of Al atom. Insoluble or poorly soluble.

As described above, the solubility of the organic aluminum oxy compound in benzene was determined by suspending the organic aluminum oxy compound corresponding to 100 milligram atoms of Al in 100 ml of benzene, mixing the mixture at 60 ° C. with stirring for 6 hours, and then adding a jacket. Using a G-5 glass filter, filtration was carried out while heating at 60 ° C., and the solid part separated on the filter was washed four times with 50 ml of benzene at 60 ° C., and then the total amount of Al atoms present in the total filtrate was measured. It is determined by measuring the abundance (x millimeter model). (X%).

Analysis of the benzene-insoluble organoaluminum oxy compound as described above by infrared spectroscopy (IR) shows that
1220cm absorbance at around ^-1 (D _1220), the ratio of the absorbance at around _{^{1260cm -1 (D 1260) (D}} 1260 / D 1220) , the
0.09 or less, preferably 0.08 or less, particularly preferably 0.04 to 0.07
Is desirably within the range.

The infrared spectroscopic analysis of the organic aluminum oxy compound is performed as follows.

First, in a nitrogen box, the organoaluminum oxy compound and Nujol are ground in an agate pestle to form a paste.

Next, the paste-like sample is sandwiched between KBr plates, and an IR spectrum is measured by IR-810 manufactured by JASCO Corporation under a nitrogen atmosphere.

Of the organoaluminum oxy compound used in the present invention
The IR spectrum is shown in FIG.

From the IR spectrum thus obtained, D ₁₂₆₀ / D
_The value of D ₁₂₆₀ / D ₁₂₂₀ is obtained as follows.

(B) 1280 cm ^-1 bear maximum point in the vicinity of and around 1240 cm ^-1, which is the baseline L _1.

(B) the transmittance (T%) at the absorption minimum point near 1260 cm ^-1 ,
A perpendicular line is drawn from this minimum point to the wave number axis (horizontal axis), the transmittance (T ₀ %) at the intersection of this perpendicular line and the baseline L ₁ is read, and the absorbance (D ₁₂₆₀ = logT ₀ ) around ₁₂₆₀ cm ⁻¹ / T).

(C) Similarly bear maximum point in the vicinity of 1280 cm ^-1 and near 1180 cm ^-1, which is the baseline L _2.

(D) Transmittance at the minimum absorption point near 1220 cm ^-1 (T '%)
From this minimum point, a perpendicular is drawn to the wave number axis (horizontal axis), and the transmittance (T ′) at the intersection of this perpendicular and the baseline L ₂ is drawn.
₀ %) and absorbance near ₁₂₂₀ cm ^-1 (D ₁₂₂₀ = log)
T ′ ₀ / T ′) is calculated.

(E) D ₁₂₆₀ / D ₁₂₂₀ is calculated from these values.

The IR spectrum of a conventionally known benzene-soluble organic aluminum oxy compound is shown in FIG. As can be seen from FIG. 3, the benzene-soluble organoaluminum oxy compound has a D ₁₂₆₀ / D ₁₂₂₀ value of about 0.10 to
The benzene-insoluble organoaluminum oxy compound used in the present invention is between 0.13 and benzene-soluble organoaluminum oxy compound known in the art and D ₁₂₆₀ / D ₁₂₂₀
The values are clearly different.

The benzene-insoluble organoaluminum oxy compound as described above is [Wherein, R ¹ is a hydrocarbon group having 1 to 12 carbon atoms].

In the above alkyloxyaluminum unit, R ¹
Is specifically a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a cyclohexyl group, a cyclooctyl group, or the like. . Of these, a methyl group and an ethyl group are preferable, and a methyl group is particularly preferable.

This benzene-insoluble organoaluminum oxy compound is In addition to the alkyloxyaluminum unit represented by Wherein R ¹ is the same as above, and R ² is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryloxy group having 6 to 20 carbon atoms. , Hydroxyl, halogen or hydrogen, R ¹ and R ²
Represents different groups from each other]. In that case, the alkyloxyaluminum unit Is preferably an organoaluminum oxy compound having an alkyloxyaluminum unit containing at least 30 mol%, preferably at least 50 mol%, particularly preferably at least 70 mol%.

Next, a method for producing the benzene-insoluble organic aluminum oxy compound as described above will be specifically described.

This benzene-insoluble organoaluminum oxy compound is obtained by contacting a solution of aluminoxane with water or an active hydrogen-containing compound.

Examples of the active hydrogen-containing compound include alcohols such as methanol, ethanol, n-propanol and isopropal, diols such as ethylene glycol and hydroquinone, and organic acids such as acetic acid and propionic acid. Of these, alcohols and diols are preferred, and alcohols are particularly preferred.

The water or active hydrogen-containing compound to be brought into contact with the solution of aluminoxane is dissolved or dispersed in a hydrocarbon solvent such as benzene, toluene, or hexane, an ether solvent such as tetrahydrofuran, an amine solvent such as triethylamine, or steam or It can be used in a solid state. Or as water, crystal water of salts such as magnesium chloride, magnesium sulfate, aluminum sulfate, copper sulfate, nickel sulfate, iron sulfate, cerous chloride, etc., or inorganic compounds or polymers such as silica, alumina, aluminum hydroxide, etc. Adsorbed water or the like can also be used.

The contact reaction between the solution of aluminoxane and water or an active hydrogen-containing compound is usually carried out in a solvent such as a hydrocarbon solvent. Examples of the solvent used in this case include aromatic hydrocarbons such as benzene, toluene, xylene, cumene and cymene, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane and octadecane, cyclopentane and cyclohexane. , Cyclooctane, alicyclic hydrocarbons such as methylcyclohexane, hydrocarbon solvents such as gasoline, kerosene, petroleum fractions such as light oil, and the above-mentioned aromatic hydrocarbons, aliphatic hydrocarbons, halides of alicyclic hydrocarbons And halogenated hydrocarbons such as chlorinated products and brominated products, and ethers such as ethyl ether and tetrahydrofuran. Among these media, aromatic hydrocarbons are particularly preferred.

Water or an active hydrogen-containing compound used in the contact reaction is 0.1 to 0.1% with respect to Al atoms in a solution of aluminoxane.
It is used in an amount of 5 mol, preferably 0.2 to 3 mol. The concentration in the reaction system is usually 1 ×
It is preferably in the range of 10 ^{-3 to} 5 graph atoms / l, preferably 1 × 10 ^{-2 to} 3 g atoms / l, and the concentration of water in the reaction system is usually 2 × 10 ^{-4 to} 5 mol / l. l preferably 2 × 10 ^-3
Preferably, the concentration is 3 mol / l.

The contact of the aluminoxane solution with water or an active hydrogen-containing compound may be carried out specifically as follows.

(1) A method in which a solution of aluminoxane is brought into contact with water or a hydrocarbon solvent containing an active hydrogen-containing compound.

(2) A method of contacting the aluminoxane with the vapor by, for example, blowing steam of an active hydrogen-containing compound into the solution of the aluminoxane.

(3) A method in which a solution of aluminoxane is brought into direct contact with water or ice or an active hydrogen-containing compound.

(4) Aluminoxane solution is mixed with a hydrocarbon suspension of a compound containing adsorbed water or a water of crystallization or a hydrocarbon suspension of a compound to which an active hydrogen-containing compound is adsorbed. With water as adsorbed water or water of crystallization.

The aluminoxane solution as described above may contain other components as long as the reaction between the aluminoxane and water or the active hydrogen-containing compound does not adversely affect the reaction.

The contact reaction between the solution of aluminoxane and water or an active hydrogen-containing compound is usually carried out at -50 to 150 ° C, preferably at 0 to 1 ° C.
The reaction is carried out at a temperature of 20 ° C, more preferably 20 to 100 ° C.
The reaction time varies greatly depending on the reaction temperature,
Usually, it is about 0.5 to 300 hours, preferably about 1 to 150 hours.

The benzene-insoluble organoaluminum oxy compound can also be obtained directly by bringing the above-mentioned organoaluminum into contact with water. In this case, water is used in such an amount that the amount of the organic aluminum atoms dissolved in the reaction system is 20% or less based on all the organic aluminum atoms.

Water to be brought into contact with the organoaluminum compound can be used by dissolving or dispersing it in a hydrocarbon solvent such as benzene, toluene, and hexane, an ether solvent such as tetrahydrofuran, an amine solvent such as triethylamine, or in the form of steam or ice. . As water, it was adsorbed on water of crystallization of salts such as magnesium chloride, magnesium sulfate, aluminum sulfate, copper sulfate, nickel sulfate, iron sulfate, and cerous chloride, or on inorganic compounds or polymers such as silica, alumina and aluminum hydroxide. Adsorbed water or the like can also be used.

The contact reaction between the organoaluminum compound and water is usually
Performed in a hydrocarbon solvent. Examples of the hydrocarbon solvent used in this case include aromatic hydrocarbons such as benzene, toluene, xylene, cumene and cymene; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane and octadecane; and cyclopentane. , Cyclohexane, cyclooctane, alicyclic hydrocarbons such as methylcyclohexane, petroleum fractions such as gasoline, kerosene, and gas oil, or halides of the above aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons, especially chlorinated products And hydrocarbon solvents such as bromides. In addition, ethers such as ethyl ether tetrahydrofuran can be used. Of these media, aromatic hydrocarbons are particularly preferred.

The concentration of the organoaluminum compound in the reaction system is usually in the range of 1 × 10 ^{−3 to} 5 g atoms / l, preferably 1 × 10 ^{−2 to} 3 g atoms / l in terms of aluminum atoms, The concentration of water in the reaction system is usually 1 × 10 ⁻³ to
The concentration is preferably 5 mol / l, preferably 1 × 10 ^{-2 to} 3 mol / l. At this time, the organic aluminum atoms dissolved in the reaction system account for 20% of the total organic aluminum atoms.
% Or less, preferably 10% or less, more preferably 0 to 5%
It is desirable that

The contact between the organoaluminum compound and water may be specifically performed as follows.

(1) A method of contacting a hydrocarbon solution of organoaluminum with a hydrocarbon solvent containing water (2) A method of contacting organoaluminum with steam by blowing steam into the hydrocarbon solution of organoaluminum .

(3) A method in which a hydrocarbon solution of an organic aluminum is mixed with a hydrocarbon suspension of a compound containing adsorbed water or a compound containing water of crystallization, and the organic aluminum is brought into contact with the adsorbed water or the water of crystallization.

(4) A method in which ice is brought into contact with a hydrocarbon solution of an organic aluminum.

The organic aluminum hydrocarbon solution as described above may contain other components as long as the reaction between the organic aluminum and water is not adversely affected.

The contact reaction between the organoaluminum compound and water is usually
100-150 ° C, preferably -70-100 ° C, more preferably -5
It is performed at a temperature of 0 to 80 ° C. The reaction time varies greatly depending on the reaction temperature, but is usually about 1 to 200 hours, preferably about 2 to 100 hours.

The olefin polymerization catalyst used in the present invention may contain an organoaluminum compound [C] as necessary.

As such an organoaluminum compound [C],
For example, R _n ⁶ AlX _3-n (wherein, R ⁶ is a hydrocarbon group having 1 to 12 carbon atoms, X is halogen or hydrogen, and n is 1 to
3) can be exemplified.

In the above formula, R ⁶ is a hydrocarbon group having 1 to 12 carbon atoms such as an alkyl group, a cycloalkyl group or an aryl group, and specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isobutyl group. Group, pentyl group, hexyl group, octyl group, cyclopentyl group, cyclohexyl group, phenyl group, tolyl group and the like.

Specific examples of such an organoaluminum compound include the following compounds.

Trimethyl aluminum, triethyl aluminum,
Trialkyl aluminums such as triisopropyl aluminum, triisobutyl aluminum, trioctyl aluminum and tri 2-ethylhexyl aluminum.

Alkenyl aluminum such as isoprenyl aluminum.

Dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride and dimethylaluminum bromide.

Alkyl aluminum sesquichlorides such as methyl aluminum sesquichloride, ethyl aluminium sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride, and ethyl aluminum sesquibromide;

Alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride and ethylaluminum dibromide;

Alkyl aluminum hydrides such as diethyl aluminum hydride and diisobutyl aluminum hydride.

As the organoaluminum ^{_{compound, R 6 n AlY 3-n}} ( wherein R ⁶ is as defined above, Y is -OR ⁷ group, -OSiR ⁸ ₃ group,
-OAlR ⁹ ₂ group, NR ¹⁰ ₂ group, -SiR ¹¹ ₃ group or Wherein n is 1-2, R ⁷ , R ⁸ , R ⁹ and R ¹³ are a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group, etc., and R ¹⁰ is hydrogen,
Examples include a methyl group, an ethyl group, an isopropyl group, a phenyl group, and a trimethylsilyl group, and R ¹¹ and R ¹² are a methyl group, an ethyl group, and the like. ) Can also be used.

As such an organoaluminum compound, specifically, the following compounds are used.

_{^{(I) R 6 n Al (}} OR 7) 3-n dimethylaluminum methoxide, diethylaluminum ethoxide and diisobutylaluminum _{^{methoxide, (ii) R 6 n Al}} (OSiR 8 3) 3-n Et 2 Al (OSiMe ₃₎ (such as _{iso-Bu) 2 Al (OSiMe} 3) (iso-Bu) 2 Al (OSiEt 3), (iii) R 6 n Al (OAlR 9 2) 3-n Et 2 AlOAlEt 2 (iso-Bu) ₂ AlOAl (iso-Bu) ₂ etc., (iV) R ⁶ _n Al (NR ¹⁰ ₂ ) _3-n Me ₂ AlNEt ₂ Et ₂ AlNHMe Me ₂ AlNHEt Et ₂ AlN (Me ₃ Si) ₂ (iso-Bu) ₂ AlN (Me ₃ Si) ₂ etc., (V) R ⁶ _n Al (SiR ¹¹ ₃ ) _3-n (iso-Bu) ₂ AlSiMe ₃ etc. Organoaluminum compounds mentioned above, R ⁶ ₃ A
_{^{l, R 6 n Al (OR}} 7) 3-n, can be mentioned organoaluminum compounds represented by ^{_{R 6 n Al (OAlR 9 2}} ) 3-n Suitable examples, in particular R ⁶ is located at isoalkyl group , N = 2 are preferred. These organoaluminum compounds can be used as a mixture of two or more kinds.

The olefin polymerization catalyst as described above can be used by being supported on a solid inorganic compound such as silica, alumina, magnesium oxide, and magnesium chloride, or a solid organic compound such as polyethylene, polypropylene, and polystyrene.

In the present invention, an ethylene-based polymer is produced in two stages, namely, the polymerization step (a) and the polymerization step (b), using the olefin polymerization catalyst as described above.

In the polymerization step (a), ethylene is homopolymerized, or ethylene is copolymerized with another α-olefin, and the density is 0.88 g / cm ³ or more, preferably 0.89 to 0.94 g / cm ^3.
Having an intrinsic viscosity [η] of 0.3 to 3 dl / g, preferably 0.5 to 2
The dl / g ethylene polymer [I] is formed.

In this ethylene polymer [I], n-
The relationship between the decane-soluble portion (W) and the density (D) satisfies logW ≦ −50 × D + 46.4, preferably logW ≦ −50 × D + 46.3, and more preferably logW ≦ −50 × D + 46.2. Is desirable.

In the polymerization step (b), ethylene and another α-olefin are copolymerized to form an ethylene copolymer [II]. This ethylene-based copolymer [II] has a density of the ethylene-based polymer [I] obtained in the polymerization step (a).
Of the ethylene-based polymer [I], preferably 0.005 g / cm ³ or more. The intrinsic viscosity [η] of the ethylene copolymer [II]
Is the ethylene-based polymer [I] obtained in the polymerization step (a).
Is at least 1.5 times, preferably 2 to 10 times, and preferably 1 to 10 dl / g, and more preferably 1.5 to 7 dl / g.

Further, the density D of the ethylene-based polymer [I], the ethylene-based copolymer [II] or the whole polymer and the temperature T (° C.) showing the highest peak in an endothermic curve measured by a differential scanning calorimeter. It is desirable that the relationship satisfies T <450 × D-297, preferably T <500 × D-344, and more preferably T <550 × D-391.

The above two polymerization steps (a) and (b)
Are performed in any order. That is, the polymerization step (a)
, The polymerization step (b) may be performed in the presence of the obtained ethylene polymer [I] to form an ethylene copolymer [II], or the polymerization step (b) may be performed. After that, the polymerization step (a) may be performed in the presence of the obtained ethylene polymer [II] to form an ethylene polymer [I]. In any case, both steps must be performed sequentially. In other words, the polymerization step performed at a later stage must be performed in the presence of the polymer formed at the earlier stage. In this case, in the subsequent polymerization step, it is preferable to use the one used in the previous polymerization step without adding a new catalyst, since a polymer with less generation of fish eyes can be obtained.

In the polymerization step (a) and the polymerization step (b), the weight of the ethylene-based polymer [I] obtained in the polymerization step (a) is 100%.
In the case of weight parts, 10 to 1000 in the weight step (b)
It is desirable to form the ethylene-based copolymer [II] so as to be in a range of 20 parts by weight, preferably 20 to 500 parts by weight.

The intrinsic viscosity [η] of all the polymers (ethylene polymer [I] and ethylene polymer [II]) is 1 to 6 dl / g, preferably 1.2 to 4 dl / g, and the density is 0.86 to 0.94. g / cm ^3, preferably 0.87~0.93g / cm ^3, more preferably 0.88~0.92g
/ cm ³ is desirable. Furthermore, the ratio of MFR ₁₀ measured at 190 ° C under a 10 kg load to MFR ₂ measured under a 2.16 kg load (MFR
₁₀ / MFR ₂ ) is desirably 7 or more, preferably 8 to 40.

In this specification, the density D of the ethylene-based polymer [I] or the ethylene-based copolymer [II] is measured under a load of 2.16 kg.
The strand obtained at the time of MFR measurement was heat-treated at 120 ° C. for 1 hour, further cooled to room temperature over 1 hour, and then measured with a density gradient tube.

The intrinsic viscosity [η] of the polymer was measured at 135 ° C. in a decalin solvent. Furthermore, the amount of n-decane soluble part of the above polymer was measured as follows.

About 3 g of the copolymer was precisely weighed and added to 450 ml of n-decane.
After melting at ℃, slowly cool to 23 ℃. Next, n-
The n-decane was distilled off from the obtained filtrate except for the decane-insoluble portion to obtain the amount of n-decane-soluble portion (% by weight based on the total copolymer).

In the present specification, the density (D ₂ ), intrinsic viscosity [η] ₂ and n-decane soluble part amount (W ₂ ) of the polymer obtained in the second polymerization step are calculated as follows. did.

In the formula, [η] _W , [η] ₁ , and [η] ₂ are the intrinsic viscosity of the entire polymer, the intrinsic viscosity of the polymer obtained in the first stage, and the intrinsic viscosity of the polymer obtained in the second stage, respectively. F ₁ and f ₂ are the first-stage and second-stage polymerization amount fractions (f ₁ + f ₂ = 1), respectively.

D _W , D ₁ , and D ₂ are the density of the entire polymer, the density of the polymer obtained in the first step, and the density of the polymer obtained in the second step, respectively.

W _W , W ₁ , and W ₂ are respectively the n-decane soluble part amount of the entire polymer, the n-decane soluble part amount of the polymer obtained in the first stage,
This is the amount of n-decane soluble part of the polymer obtained in the second stage.

The prepolymerization is preferably carried out under a mild condition in a suspended state by adding an olefin and the above catalyst component to an inert hydrocarbon medium.

Specific examples of the inert hydrocarbon medium used in this case include fatty acid hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, methylcyclopentane, and the like. Alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride and chlorobenzene, and mixtures thereof. Among these inert hydrocarbon media, it is particularly preferable to use fatty acid hydrocarbons. The prepolymerization can be performed using the olefin itself as a solvent, or the prepolymerization can be performed in a substantially solvent-free state.

The olefin used in the prepolymerization may be the same as or different from the olefin used in the main polymerization described below, and specifically, propylene is preferred.

The reaction temperature during the prepolymerization is usually -20 to + 100 ° C,
Preferably, it is in the range of about -20 to + 40 ° C.

In the prepolymerization, a molecular weight regulator such as hydrogen can be used. Such molecular weight regulators are
It is desirable to use the polymer in an amount such that the intrinsic viscosity [η] of the polymer obtained by prepolymerization measured in decalin at 135 ° C. is about 0.2 dl / g or more, preferably about 0.5 to 10 dl / g.

The prepolymerization is carried out at about 0.1 to 5 per gram of the solid catalyst as described above.
00 g, preferably about 0.3 to 300 g, particularly preferably 1 to 100 g
It is desirable to carry out the reaction so as to produce a polymer of If the prepolymerization amount is too large, the production efficiency of the olefin polymer may decrease.

Examples of the α-olefin other than ethylene that can be used in the present invention include α-olefins having 3 to 20 carbon atoms, for example, propylene, 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene, 1-octene, 1
-Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl-1,4, 5,8-Dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and the like can be mentioned.

Further, styrene, vinylcyclohexane, diene and the like can be used.

In the present invention, the polymerization can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization or a gas phase polymerization method.

The polymerization temperature of the olefin using such an olefin polymerization catalyst is usually -50 to 200 ° C, preferably 0 to 150 ° C.
It is in the range of ° C. The polymerization pressure is usually from normal pressure to 100 kg / c.
m ² , preferably normal pressure to 50 kg / cm ² , and the polymerization reaction can be carried out by any of a batch system, a semi-continuous system, and a continuous system. The molecular weight of the resulting olefin polymer can be adjusted by the presence of hydrogen in the polymerization system or by changing the polymerization temperature.

When olefin polymerization is carried out using the olefin polymerization catalyst as described above, the transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton is usually 10 ^-5 per reaction volume. ~ 1 mmol, preferably 10 ^-4 ~ 0.
In an amount of 1 mmol, the organoaluminum oxy compound [B] is usually in an amount of 0.01 to 10 mmol, preferably 0.02 to 5 mmol, and the organoaluminum compound [C] is usually in an amount of 0 to 10 mmol, preferably 0.1 to 5 mmol. Preferably, it is used in an amount.

In the present invention, the olefin weight catalyst may contain other components useful for olefin polymerization, in addition to the above components.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 (Preparation of [B] Organoaluminum oxy compound) Al ₂ (SO ₄ ) ₃ was placed in a 400 ml flask which was sufficiently purged with nitrogen.
・ 37.1 g of 14H ₂ O and 133 ml of toluene were charged, and after cooling to −5 ° C., 47.9 ml of trimethylaluminum diluted with 152 ml of toluene was added dropwise over 1 hour. Then, 0-5 ° C
After reacting for 1 hour, the temperature was raised to 40 ° C. over 3 hours,
The reaction was further carried out at 40 ° C. for 72 hours. After the reaction, solid-liquid separation was performed by filtration, and toluene was further removed from the filtrate to obtain a white solid organoaluminumoxy compound.

(Polymerization) 900 ml of 4-methyl-1-pentene was charged into a 2 stainless steel autoclave sufficiently purged with nitrogen, and the temperature in the system was raised to 55 ° C. Thereafter, the polymerization was started by injecting 1.0 mmol of triisobutylaluminum, 0.1 mg of an organoaluminum oxy compound in terms of organoaluminum atoms, and 0.001 mmol of bis (methylcyclopentadienyl) zirconium dichloride with ethylene. While continuously supplying ethylene, the total pressure was maintained at 8 kg / cm ² · G, and polymerization was carried out at 60 ° C. for 10 minutes [step (b)]. Immediately after polymerization for 10 minutes, 0.25Nl of hydrogen
And pressurize ethylene further to increase the total pressure.
Polymerization was further performed at 12 kg / cm ² · G and 60 ° C. for 25 minutes [Step (a)]. The polymerization was stopped by adding a small amount of methanol to the polymerization system, and the obtained polymer solution was precipitated in a large amount of methanol, collected, and dried overnight at 80 ° C. under reduced pressure. As a result, [η] is 1.82 dl / g,
Density of 0.901g / cm ^3, MFR ₂ is 0.82 g / 10 min, MF
Ethylene 10-methyl-1 having an R ₁₀ / MFR ₂ of 10.5, a melting point of 95 ° C. and an n-decane soluble part content of 1.6% by weight
-53.5 g of pentene copolymer was obtained.

In addition, as a result of performing only the operation of the above step (b),
[Η] is 3.30 dl / g, the density is 0.892 g / cm ³ , and n
15.5 g of an ethylene-4-methyl-1-pentene copolymer having a decane-soluble portion of 3.9% by weight and a melting point of 87 ° C.
I got From the result of the step (b), the [η] of the ethylene-4-methyl-1-pentene copolymer obtained in the step (a) was 1.22 dl / g, and the density was 0.905 g / cm ^3. And the amount of n-decane-soluble part is 0.66% by weight, and the polymerization amount is
It was calculated to be 38.0 g.

Comparative Example 1 (Polymerization) In the step (b) of Example 1, the polymerization temperature was 100 ° C.
Except that the polymerization time was 40 minutes and the total pressure was 12 kg / cm ² · G,
Polymerization was performed in the same manner, and [η] was 1.85 dl / g, and the density was
Was 0.902g / cm ^3, MFR ₂ is 0.75 g / 10 min, MFR ₁₀ / MF
32.8 g of an ethylene / 4-methyl-1-pentene copolymer having an R ₂ of 6.0, a melting point of 94 ° C., and an n-decane soluble part content of 1.1% by weight was obtained.

Example 2 (Polymerization) After the step (b) was performed in exactly the same manner as in Example 1, 0.2 Nl of hydrogen was immediately charged, and polymerization was further performed at a total pressure of 10 kg / cm ² · G and 60 ° C for 25 minutes. [Step (a)]. The subsequent operation is performed in the same manner as in Example 1, and [η] is 1.87 dl / g.
Density of 0.897g / cm ^3, MFR ₂ is 0.65 g / 10 min, MF
R ₁₀ / MFR ₂ is 9.8, a melting point of 92 ° C., ethylene 4-methyl -1 n-decane soluble part amount is 2.4 wt%
-44.3 g of a pentene copolymer was obtained.

Ethylene 4-methyl-1 obtained in the above step (a)
-[Η] of the pentene copolymer is 1.10 dl / g and the density is
0.900 g / cm ³ , the n-decane soluble part amount was 1.6% by weight, and the polymerization amount was calculated to be 28.8 g.

[Brief description of the drawings]

1 (a) and 1 (b) are explanatory diagrams of the olefin polymerization catalyst according to the present invention, and FIG. 2 is an IR spectrum of the benzene-insoluble organoaluminum oxy compound used in the present invention; FIG. 3 is an IR spectrum of a benzene-soluble organoaluminum oxy compound.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08F 4/60-4/70 C08F 10/00-10/02 C08F 210/00-210/16 C08L 23 / 00-23/24

Claims (1)

(57) [Claims] 1. A polymerization step (a) using an olefin polymerization catalyst comprising a transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton and an organoaluminum oxy compound [B]: ethylene or ethylene And other α-olefins are polymerized or copolymerized, and the density is 0.88 g / cm
Is ³ or more, and step intrinsic viscosity [eta] form an ethylene-based polymer [I] is a 0.3~3dl / g, and the polymerization step (b): copolymerizing ethylene and other α- olefins The density is not higher than the density of the ethylene polymer [I], and the intrinsic viscosity [η] is at least 1.5 times or more of the intrinsic viscosity of the ethylene polymer [I] and 1
After performing the polymerization step (a), a polymerization step (a) is performed in the presence of the obtained ethylene-based polymer [I]. After performing (b) or performing the polymerization step (b), the polymerization step (a) is performed in the presence of the obtained ethylene-based copolymer [II]. The density is 0.86 to 0.94 g / cm ³ , characterized in that the polymerization is performed such that the ethylene-based copolymer [II] is in a ratio of 10 to 1000 parts by weight with respect to 100 parts by weight of the polymer [I]. A method for producing an ethylene polymer composition having an intrinsic viscosity [η] of 1 to 6 dl / g.