JPH09143221A - Catalyst for ethylene-based polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst for ethylene-based polymerization useful for efficiently obtaining an ethylene-based polymer polymer having a broad molecular weight distribution without generating fouling by bringing a specific solid catalyst component into contact with a specific transition metal compound. SOLUTION: This catalyst for ethylene-based polymerization is prepared by bringing (B) a transition metal compound containing a group having a conjugated electrons as ligands into contact with (A) (i) a support catalyst component obtained by baking a support which supports a chromium compound (e.g. chromium trioxide, chromium trichloride, etc.) and (ii) a solid catalyst component supporting aluminoxane as a supported catalyst component. It is preferable to use 0.01m mol-1000 mole (preferably 0.05m mole-100 mole) component B based on 1 mole chromium atom in the component A. The component (i) can be obtained by supporting 0.01-5wt.% (in terms of chromium atom) chromium compound on a support and baking it in a dry gas containing O2 at 300-1000C for 1-48 hours. A molar ratio (aluminum/chromium) in the component A is preferably 5-500 mole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ethylene polymerization catalyst. More specifically, an ethylene-based polymer having a wide molecular weight distribution is so-called fouling, in which the produced polymer particles adhere to the wall of the reactor and significantly hinder the continuation of the polymerization reaction, and in some cases, the polymerization reaction is interrupted. The present invention relates to a highly active new catalyst that can be produced without

[0002]

2. Description of the Related Art Ethylene polymers are generally and widely used as resin materials for various molded articles, and required characteristics differ depending on the molding method and application. In particular, a polymer having a relatively high molecular weight and a wide molecular weight distribution is suitable for an ethylene-based polymer used for blown film molding or hollow molding. Heretofore, many methods have been proposed for producing an ethylene polymer having the above-mentioned performance by carrying out single-stage or multi-stage polymerization using a so-called Ziegler catalyst, which is composed of a titanium compound, a magnesium compound and a halogen. (JP-A-56-9080
9, JP-A-60-106806, JP-A-2-12310
8, JP-A-4-18407, JP-A-5-23013
6). In addition, a method for producing using a so-called Phillips catalyst, in which chromium trioxide is supported on an inorganic oxide and baked, is known (pentamethylciglopentadienyl).
A method of producing a non-calcined catalyst in which a chromium compound such as (2-methylpentadienyl) chromium is supported on an inorganic oxide has also been proposed. (JP-A-3-93804).
A method for producing a Phillips catalyst or a non-calcined chromium catalyst using a catalyst treated with an organoaluminum compound such as aluminosan has also been proposed (Japanese Patent Laid-Open No. 2-10).
5806, Japanese Patent Application Laid-Open No. 2-185506, and Japanese Patent Publication No. 7-503.
739, U.S. Pat. No. 4,564,660). Furthermore, a method of carrying out two-step polymerization using a catalyst obtained by combining a Phillips catalyst with an organoaluminum compound and a Ziegler catalyst has been proposed. (JP-A-62-207
307, Japanese Patent Publication No. 7-103177).

In recent years, Phillips catalyst or Ziegler catalyst and so-called metallocene catalyst, or 2
A method for producing using a catalyst in which one or more metallocene catalysts are combined has been proposed (JP-A-1-29200).
9, Tokuyohei 1-503715, JP-A-3-20390
3, JP-A-4-220405, JP-A-6-12271
9, JP-A-7-173209, JP-A-8-41118,
JP-A-8-100018, JP-B-8-13856). However, the molecular weight distribution of the ethylene-based polymer produced using these catalysts is not at a sufficient level, and when the catalyst system disclosed in JP-A-1-292009 is used, the molecular weight is relatively high and Although a polymer having a wide molecular weight distribution can be produced, fouling cannot be sufficiently prevented, and further improvement in catalyst activity is required.

[0004]

DISCLOSURE OF THE INVENTION The object of the present invention is to improve the above-mentioned problems and to produce an ethylene polymer having a wide molecular weight distribution, which causes fouling which is a serious obstacle to the continuation of the reaction during the polymerization. It is an object of the present invention to provide a highly active catalyst that can be produced without any treatment.

[0005]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have found that a carrier catalyst component obtained by calcining a carrier carrying a chromium compound is converted into a solid catalyst component carrying aluminoxane. Further, a catalyst for ethylene polymerization in which a transition metal compound having a group having a conjugated π-electron as a ligand is brought into contact, a carrier catalyst component obtained by firing a carrier supporting a chromium compound, and a solid catalyst supporting aluminoxane In the polymerization, 0.01 mol to 1000 mol of conjugated π is added to 1 mol of chromium atom in the solid catalyst component.
An ethylene-based polymerization catalyst obtained by contacting a transition metal compound having an electron group as a ligand, a chromium compound as a carrier, and a chromium atom of 0.01 to
After supporting 5% by weight, the carrier catalyst component is or is described as a carrier catalyst component calcined in a dry gas containing oxygen at 300 to 1000 ° C. for 1 to 48 hours, and a mole of aluminum / chromium in the solid catalyst component. Ratio is 5
~ 500 is the catalyst for ethylene-based polymerization described above, 300 to 1000 after supporting a chromium compound on a carrier.
A carrier catalyst component calcined in a dry gas containing oxygen at 1 to 48 hours for supporting aluminoxane to produce a solid catalyst component, and then during polymerization, with respect to 1 mol of chromium atom in the solid catalyst component, A method for producing an ethylene-based polymerization catalyst, which comprises contacting a transfer metal compound having a group having a conjugated π-electron of 0.01 mmol to 1000 mol as a ligand. On the other hand, using an ethylene-based polymerization catalyst obtained by contacting an organometallic compound and the ethylene-based polymerization catalyst according to any one of the above, ethylene alone as a monomer, or α
The above object was achieved by developing a method for producing an ethylene-based polymer in which ethylene containing an olefin is heated in the range of 0 to 300 ° C.

The ethylene-based polymerization catalyst according to the present invention will be specifically described below. As the ethylene-based polymerization catalyst according to the present invention, a solid catalyst component in which aluminoxane is supported on a carrier catalyst component obtained by firing a carrier on which a chromium compound is supported is produced, and conjugated π electrons are added to the solid catalyst component. A transition metal compound having a group having a ligand,
And an ethylene-based polymerization catalyst obtained by bringing an organometallic compound into contact with the catalyst, if desired.

The chromium compounds used in the present invention include chromium trioxide or chromium oxides, halides, oxyhalides, nitrates, sulfates, acetates, oxalates,
Mention may be made of any chromium compound which can be converted into chromium oxide under the firing conditions of the carrier according to the invention, such as chromate esters and organic chromium compounds. After this calcination, at least some of the chromium atoms must be in the hexavalent state.
Specific examples of the chromium compound include chromium trioxide, chromium trichloride, chromyl chloride, chromium nitrate, chromium sulfate, chromium acetate, chromium oxalate, ammonium chromate, bis (tert-butyl) chromate, bis (cyclopentadienyl). ) Chromium, acetylacetone chromium and the like can be mentioned.

The method of supporting the chromium compound on the carrier is as follows. The carrier is an aqueous chromium compound or pentane, hexane,
A method of dipping and supporting in a hydrocarbon solution such as heptane, cyclohexane, decane, benzene and toluene is preferably used. The supporting temperature is generally 100 ° C. or lower, preferably 0 to 40 ° C. The ratio of the chromium compound used to the carrier is preferably such that the content of chromium atoms in the resulting carrier is in the range of 0.01 to 5% by weight. Further, by adding a titanium compound to the catalyst system, the molecular weight of the polymer can be lowered to improve the fluidity, or by adding a fluorine compound, the polymerizability can be improved.

The carrier used in the present invention is an oxide of an element of Group 2, 4, 13 or 14 (according to the 1990 rules of inorganic chemistry) or a phosphate of an element of Periodic Table, Examples include magnesia, titania, zirconia, alumina, silica, silica-titania, silica-zirconia, silica-alumina, aluminum phosphate, gallium phosphate, and mixtures thereof. The carrier, specific surface area of 50~1000m ² / g, preferably 200~800m ² / g, the pore volume 0.5
3.0cm ³ / g, preferably 1.0~2.5m ³ /
g, average particle size 10 to 200 μm, preferably 30 to 1
Those having a size of 50 μm are preferably used. The carrier catalyst component used in the present invention, after supporting a chromium compound on a calcined carrier or an uncalcined carrier, is dried at a temperature of 300 to 1000 ° C. for 1 to 48 hours, preferably by a dry gas,
After removing the solvent, it is obtained by baking in a state fluidized by a dry gas containing oxygen.

The aluminoxane used in the present invention includes compounds represented by the general formula (1) or (2).

[0011]

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[0012]

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(R ¹ is methyl, ethyl, propyl, n
A hydrocarbon group such as -butyl and isobutyl, preferably a methyl group and an isobutyl group. k is 1 to 1
It is an integer of 00, preferably 4 or more, particularly preferably 8 or more. ) The production of compounds of this type is known,
For example, a suspension of an inert hydrocarbon solvent such as pentane, hexane, heptane, cyclohexane, decane, benzene, and toluene of salts having water of crystallization (copper sulfate hydrate, aluminum sulfate hydrate, etc.) And a method in which solid, liquid or gaseous water is allowed to act on the trialkylaluminum in the above-mentioned hydrocarbon solvent. Further, an aluminoxane represented by the general formula (3) or (4) may be used.

[0014]

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[0015]

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(R ² is methyl, ethyl, propyl, n
A hydrocarbon group such as -butyl and isobutyl, preferably a methyl group and an isobutyl group. R ³ is selected from hydrocarbon groups such as methyl, ethyl, propyl, n-butyl and isobutyl, halogen such as chlorine and bromine, hydrogen and hydroxyl group, and is different from R ² . R ³ may be the same or different. m is usually an integer of 1 to 100, preferably 3 or more, and m + n is 2 to 100, preferably 6 or more. ) In the general formula (3) or (4), [O-A1
The (R ² )] _m unit and the [O-A1 (R ³ ) _n ] unit may be block-bonded or may be regularly or irregularly bonded at random. The method for producing such an aluminoxane is the same as that for the aluminoxane represented by the general formula described above. Instead of one kind of trialkylaluminum, two or more kinds of trialkylaluminum are used or one or more kinds of trialkylaluminum and one kind are used. The above dialkylaluminum monohalide or dialkylaluminum monohydride may be used.

The solid catalyst component can be obtained by suspending the carrier catalyst component in an inert hydrocarbon solvent such as pentane, hexane, heptane, cyclohexane, decane, benzene and toluene in advance, and then adding the above-mentioned inert carbonization of aluminoxane. It is carried out by contacting with a hydrogen solution. Regarding the amount of aluminoxane used, the amount of aluminum atom in the aluminoxane is 5 to 500 relative to 1 mol of chromium atom in the carrier catalyst component.
Is a mole. The amount of solvent is 5 to 1 per 1 g of the carrier catalyst component.
00 ml, the contact temperature is 0 to 60 ° C., preferably 20 to 5
The contact time at 0 ° C. is 10 minutes to 10 hours, preferably 20 minutes to 5 hours. After contact, the solvent is removed under vacuum or separated by filtration to give the solid catalyst component.

The ligand of the group having a conjugated π electron used in the present invention is a ligand having a cyclopentadienyl skeleton, an amidinato skeleton or an allyl skeleton. Examples of the ligand having a cyclopentadienyl skeleton include a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, an n-butylcyclopentadienyl group, and a tert-butylcyclopentadienyl group. Alkyl-substituted cyclopentadienyl groups such as enyl group, dimethylcyclopentadienyl group, pentamethylcyclopentadienyl group, alkylsilyl-substituted cyclopentadienyl groups such as trimethylsilylcyclopentadienyl group,
Examples thereof include an alkylgermyl-substituted cyclopentadienyl group such as a trimethylgermylcyclopentadienyl group, an indenyl group with or without a similar substituent, a fluorenyl group, and the like.

Examples of the ligand having an amidinato skeleton include an amidinato group, an alkyl-substituted amidinato group such as N, N ^, -bis (n-butyl) amidinato group, N, N ^, -bis (trimethylsilyl) amidinato group, and the like. Alkylsilyl-substituted amidinato group of N, N ^, -
Aryl-substituted amidinato group such as bis (phenyl) amidinato group, N, N ^, -bis (n-butyl) benzamidinato group, N, N ^, -bis (2,6-dimethylphenyl) benzamidinato group, etc. And an amidinato group having a plurality of kinds of substituents. In addition, examples of the ligand having an allyl skeleton include an allyl group having or not having the same substituent as described above.

The transition metal used in the present invention is a transition metal element of Group 3, 4, 5 or 6 of the Periodic Table (according to the 1990 rules of the Inorganic Chemistry Nomenclature), preferably Group 4 of the Periodic Table. Transition metal elements of titanium, zirconium,
It is preferably selected from hafnium, and particularly preferably zirconium and hafnium. The transition metal compound used in the present invention includes general formulas (5), (6),
(7), (8), (9), (10) or (11) Formula (Cp ¹ ) (Cp ² ) _r Me (Q ¹ ) _3-r ... (5) R ⁷ (Cp ¹ ) ( Cp ² ) Me (Q ¹ ) (Q ² ) ... (6) R ⁷ (Cp ¹ ) (Y) Me (Q ¹ ) (Q ² ) ... (7)

[0021]

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[Chemical 6]

[0022]

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[In the formula, Cp ¹ and Cp ² are ligands having the above-mentioned cyclopentadienyl skeleton, and may be the same or different, and R ⁴ to R ⁶ are hydrogen and 1 to 20 carbon atoms. Is a hydrocarbon group such as alkyl, alkenyl, aryl, araryl, aralkyl, and alicyclic, an alkylsilyl group or an alkylgermyl group, which may be the same or different, and R ⁷ has 1 to 20 carbon atoms. Group, an alkylgermylene group or an alkylsilylene group, X ¹ and X ² are carbon or nitrogen, and they may be the same or different, and Q
¹ and Q ² are hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, a siloxy group or halogen, which may be the same or different, and Y is -O.
-, - S -, - NR 8 -, - PR 8 - (R 8 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated alkyl or halogenated aryl.) With an electron donor ligand represented by And Me is a transition metal and r is 0 or 1. ] The transition metal compound represented by these is mentioned.

Examples of the hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ to R ⁶ in the above general formula include methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, amyl, isoamyl, hexyl, heptyl, octyl, Examples thereof include alkyl groups such as nonyl, decyl and cetyl, examples of aryl groups include phenyl, examples of alkylsilyl groups include trimethylsilyl, and examples of alkylgermyl groups include trimethylgermyl. In the above general formula, R ⁷ is an alkylene group having 1 to 20 carbon atoms, an alkylgermylene group or an alkylsilylene group. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, an isopropylidene group, a cyclopentylidene group, a cyclohexylidene group, a tetrahydropyran-4-ylidene group, a diphenylmethylene group, and the like. , A dimethylsilylene group, a diphenylsilylene group, and the like, and an alkylgermylene group includes a dimethylgermylene group, a diphenylgermylene group, and the like. X ¹ and X ² are carbon or nitrogen, which may be the same or different, and
^1, Q ² is a hydrocarbon group having 1 to 20 carbon atoms such as alkyl, alkenyl, aryl, araryl, aralkyl, etc., an alkoxy group, an aryloxy group, a siloxy group or halogen, which may be the same or different. Furthermore, Y is -O
-, - S -, - NR 8 -, - PR 8 - is an electron donor ligand represented by. Where R ⁸ is hydrogen or 1 carbon
To 20 hydrocarbon groups such as alkyl, alkenyl, aryl, araryl and aralkyl, or alkyl halides or aryl halides. In particular,
Methyl, ethyl, propyl, butyl, isobutyl, te
Examples thereof include alkyl groups such as rt-butyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, decyl and cetyl, as well as phenyl group and benzyl group. In ^{this, -NR 8 -, - PR 8} - type ligand is preferred.

General formulas (5), (6), (7), (8),
As the transition metal compound represented by the formula (9), (10), or (11), specific compounds in which Me is zirconium are exemplified. As the transition metal compound represented by the general formula (5), bis (cyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (n-propylcyclopentadienyl) zirconium dichloride, bis (N-Butylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dimethyl, bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium Dichloride,
(Cyclopentadienyl) (methylcyclopentadienyl) zirconium dichloride, (cyclopentadienyl) (n-butylcyclopentadienyl) zirconium dichloride, (cyclopentadienyl) (indenyl)
Zirconium dichloride, (cyclopentadienyl)
Examples thereof include (fluorenyl) zirconium dichloride, cyclopentadienylzirconium trichloride, cyclopentadienylzirconium trimethyl, pentamethylcyclopentadienylzirconium trichloride, pentamethylcyclopentadienylzirconium trimethyl and the like.

Examples of the transition metal compound represented by the general formula (6) include dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride, isopropylidenebis (methylcyclopentadienyl) zirconium dichloride, ethylenebis (indenyl). Zirconium dichloride, ethylene bis (4,5,6,7, -tetrahydro-1-indenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (fluorenyl)
Zirconium dichloride, isopropylidene (cyclopentadienyl) (indenyl) zirconium dichloride, isopropylidene, (tert-butylcyclopentadienyl) (tert-butylindenyl) zirconium dichloride, isopropylidene (tert-butylcyclopentadienyl) (Tert-butylindenyl) zirconium dimethyl etc. can be illustrated. Examples of the transition metal compound represented by the general formula (7) include ethylene (tert-butylamide) (tetramethylcyclopentadienyl) zirconium dichloride, ethylene (methylamide) (tetramethylcyclopentadienyl) zirconium dichloride, dimethylsilylene. (Tert-Butylamido) (tetramethylcyclopentadienyl) zirconium dichloride, dimethylsilylene (tert-
Butyramide) (tetramethylcyclopentadienyl)
Examples thereof include zirconium dibenzyl, dimethylsilylene (benzylamide) (tetramethylcyclopentadienyl) zirconium dibenzyl, dimethylsilylene (phenylamide) (tetramethylcyclopentadienyl) zirconium dichloride and the like.

Examples of the transition metal compound represented by the general formula (8) include (cyclopentadienyl) (N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride, (cyclopentadienyl) ( N, N ^, −
Bis (n-butyl) benzamidinato) zirconium dichloride, (cyclopentadienyl) (N, N ^, -bis (phenyl) benzamidinato) zirconium dichloride, (cyclopentadienyl) (N, N ^, -) Bis (2,6-dimethylphenyl) benzamidinato) zirconium dichloride, (cyclopentadienyl)
(N, N ^, -bis (2,6-di-tert-butylphenyl) benzamidinato) zirconium dichloride,
(N-Butylcyclopentadienyl) (N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride, (n-butylcyclopentadienyl)
N, N ^, -bis (n-butyl) benzamidinato) zirconium dichloride, (n-butylcyclopentadienyl) (N, N ^, -bis (phenyl) benzamidinato) zirconium dichloride, (pentamethylcyclo Pentadienyl (N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride, (pentamethylcyclopentadienyl) (N, N ^, -bis (n-
Butyl) benzamidinato) zirconium dichloride, (pentamethylcyclopentadienyl) (N, N ^,
-Bis (phenyl) benzamidinato) zirconium dichloride, (indenyl) N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride, (indenyl) (N, N ^, -bis (n-butyl) benzamid Examples thereof include dinato) zirconium dichloride and (indenyl) (N, N ^, -bis (phenyl) benzamidinato) zirconium dichloride.

The transition metal compound represented by the general formula (9) is dimethylsilylene (cyclopentadienyl).
(N, N ^, -bis (trimethylsilyl) amidinato)
Zirconium dichloride, dimethylsilylene (cyclopentadienyl) (N, N ^, -bis (phenyl) amidinato) zirconium dichloride, dimethylsilylene (cyclopentadienyl) (N, N ^, -bis (n-butyl)
Amidinato) zirconium dichloride, dimethylsilylene (tetramethylcyclopentadienyl) (N, N ^,
-Bis (trimethylsilyl) amidinato) zirconium dichloride, dimethylsilylene (tetramethylcyclopentadienyl) (N, N ^, -bis (phenyl) amidinato) zirconium dichloride, dimethylsilylene (tetramethylcyclopentadienyl) (N, N ^, -Bis (n-butyl) amidinato) zirconium dichloride, dimethylsilylene (n-butylcyclopentadienyl) (N, N ^, -bis (trimethylsilyl) amidinato) diclonium dichloride, dimethylsilylene (n-)
Butylcyclopentadienyl) (N, N ^, -bis (phenyl) amidinato) zirconium dichloride, dimethylsilylene (n-butylcyclopentadienyl) (N,
N ^, -bis (n-butyl) amidinato) zirconium dichloride, dimethylsilylene (indenyl) (N, N
^, -Bis (trimethylsilyl) amidinato) zirconium dichloride, dimethylsilylene (indenyl)
(N, N ^, -bis (phenyl) amidinato) zirconium chloride, dimethylsilylene (indenyl) (N,
Examples include N ^, -bis (n-butyl) amidinato) zirconium dichloride and the like.

Examples of the transition metal compound represented by the general formula (10) include bis (N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride and bis (N, N ^, -bis (phenyl) benz. Amidinato)
Zirconium dichloride, bis (N, N ^, -bis (n-
Examples thereof include butyl) benzamidinato) zirconium dichloride. Examples of the transition metal compound represented by the general formula (11) include dimethylsilylenebis (N, N ^, -bis (trimethylsilyl) amidinato) zirconium dichloride, and dimethylsilylenebis (N, N ^, -bis (phenyl) amidinato) zirconium. Dichloride, dimethylsilylenebis (N, N ^, -bis (n-butyl) amidinato) zirconium dichloride, isopropylidenebis (N, N ^, -bis- (trimethylsilyl) amidinato) zirconium dichloride, isopropylidenebis (N, N ^, - Examples include bis (phenyl) amidinato) zirconium dichloride and isopropylidenebis (N, N ^, -bis (n-butyl) amidinato) zirconium dichloride.

In the zirconium compound as described above,
It is also possible to exemplify a transition metal compound in which zirconium is changed to hafnium or titanium. Further, the transition metal compound according to the present invention can be used alone or in combination of two or more kinds. The amount of the transition metal compound used is 0.01 mmol to 1000 mol, preferably 0.05 mmol to 1 mol of the transition metal compound, relative to 1 mol of chromium atom in the solid catalyst component.
00 mole.

The catalyst of the present invention is formed by contacting a solid catalyst component, a transition metal compound, in a reactor in the presence or absence of ethylene. The contact between the two is preferably carried out immediately before the polymerization reaction as much as possible, and the solid catalyst component and the transition metal compound are used for the polymerization reaction within 1 hour after the contact, or these components are separately inserted into the polymerization reactor,
It is used for the polymerization reaction. In this case, the solid catalyst component is previously suspended in an inert hydrocarbon solvent such as isobutane, pentane, hexane, heptane, cyclohexane, decane, benzene and toluene, and then contacted with an inert hydrocarbon solution of a transition metal compound. Done by The contact temperature is 0 to 120 ° C. A more preferable ethylene-based polymerization catalyst is one in which a solid catalyst component and a transition metal compound separately dispersed in a reaction solvent are prepared in advance, and the reaction solvent-solid catalyst component is charged into a reactor sufficiently replaced with nitrogen. , The temperature is raised to the reaction temperature, then the partial pressure of the monomer such as ethylene is increased to start the polymerization, and when the consumption of ethylene begins (when the so-called Phillips catalyst induction period ends), a transition metal compound or According to the above, the transition metal compound and the organometallic compound described later are charged into the polymerization reactor and brought into contact with each other.

When the organometallic compound is used together with the above-mentioned catalyst, it is more effective in preventing fouling and improving activity. The organometallic compound used in the present invention is an organometallic compound of an element of Group 1, 2 or 3 of the Periodic Table (according to the rules of Inorganic Chemistry Nomenclature 1990), and the metal is lithium, magnesium or aluminum. Specific compounds are exemplified. Examples of the organometallic compound of lithium include methyllithium, ethyllithium, n-propyllithium, n-butyllithium, isobutyllithium, sec.
Examples thereof include alkyl lithium such as -butyl lithium, tert-butyl lithium, n-pentyl lithium, and isopentyl lithium. Examples of the organometallic compound of magnesium include n-butylethyl magnesium and di-se.
Examples thereof include dialkyl magnesium such as c-butyl magnesium, n-butyl-sec-butyl magnesium, di-tert-butyl magnesium, dineopentyl magnesium, and di-n-hexyl magnesium. Examples of organometallic compounds of aluminum include trimethyl aluminum, triethyl aluminum, tri-n-propyl aluminum, triisopropyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tri-sec-butyl aluminum, and tri-ter.
t-butyl aluminum, tripentyl aluminum,
Trialkyl aluminum such as trihexyl aluminum, trioctyl aluminum, tricyclohexyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diisobutyl aluminum chloride, dialkyl aluminum halides, dimethyl aluminum methoxide, dialkyl aluminum alkoxide such as diethyl aluminum ethoxide, Examples thereof include dialkylaluminum ary-loxides such as diethylaluminum phenoxide.

Examples of the organic metal compound composed of lithium and aluminum include lithium tetramethylaluminate,
Lithium trimethylethylaluminate, lithium trimethylpropylaluminate, lithium trimethylbutylaluminate, lithium trimethylhexylaluminate, lithium trimethyloctylaluminate, lithium triethylmethylaluminate, lithium tetraethylaluminate, lithium triethylpropylaluminate, lithium triethylbutyl Aluminate, lithium triethylhexylaluminate, lithium triethyloctylaluminate, lithium tributylmethylaluminate, lithium tributylethylaluminate, lithium tributylpropylaluminate, lithium tetrabutylaluminate, lithium tributylhexylaluminate, lithium tributyloctylaluminate , Lithium Isobutyl methyl aluminate,
Lithium triisobutyl ethyl aluminate, lithium triisobutyl propyl aluminate, lithium triisobutyl butyl aluminate, lithium triisobutyl hexyl aluminate, lithium triisobutyl octyl aluminate, lithium trihexyl methyl aluminate, lithium trihexyl ethyl aluminate, lithium Trihexyl butyl aluminate, lithium tetrahexyl aluminate, lithium trihexyl octyl aluminate, lithium trioctyl methyl aluminate, lithium trioctyl ethyl aluminate, lithium trioctyl ethyl aluminate, lithium trioctyl butyl aluminate, lithium trioctyl Examples thereof include tylhexyl aluminate and lithium tetraoctyl aluminate.

Examples of the organometallic compound composed of magnesium and aluminum include ethyl magnesium tetramethyl aluminate, ethyl magnesium trimethyl ethyl aluminate, ethyl magnesium trimethyl propyl aluminate, ethyl magnesium trimethyl butyl aluminate, ethyl magnesium trimethyl hexyl aluminate, Ethyl magnesium trimethyl octyl aluminate, ethyl magnesium triethyl methyl aluminate, ethyl magnesium tetraethyl aluminate,
Ethyl magnesium triethyl propyl aluminate,
Ethyl magnesium triethyl butyl aluminate, ethyl magnesium triethyl hexyl aluminate, ethyl magnesium triethyl octyl aluminate, ethyl magnesium tributyl methyl aluminate, ethyl magnesium tributyl ethyl aluminate, ethyl magnesium tetrabutyl aluminate, ethyl magnesium tributyl hexyl aluminate, Ethylmagnesium tributyloctylaluminate, ethylmagnesium triisobutylmethylmagnesium, ethylmagnesium triisobutylethylaluminate, ethylmagnesium triisobutylbutylaluminate, ethylmagnesium triisobutylhexylaluminate, ethylmagnesium triisobutyloctylaluminate, butylmagnesi Mutetramethylaluminate, butylmagnesium trimethylethylaluminate, butylmagnesium trimethylpropylaluminate, butylmagnesium trimethylbutylaluminate, butylmagnesium trimethylhexylaluminate, butylmagnesium trimethyloctylaluminate, butylmagnesium triethylmethylaluminate, butylmagnesium Tetraethylaluminate, butylmagnesium triethylpropylaluminate, butylmagnesium triethylbutylaluminate, butylmagnesium triethylhexylaluminate, butylmagnesium triethyloctylaluminate, butylmagnesium triisobutylmethylaluminate, butylmagnesium triisobutylethylaluminate Butyl magnesium tetraisobutyl aluminate, butyl magnesium triisobutyl hexyl aluminate, butyl magnesium triisobutyl octyl aluminate, hexyl magnesium tetramethyl aluminate, hexyl magnesium trimethylethyl aluminate, hexyl magnesium trimethylpropyl aluminate, hexyl magnesium trimethylbutyl aluminate Hexylmagnesium trimethylhexylaluminate, hexylmagnesium trimethyloctylaluminate, hexylmagnesium triethylmethylaluminate, hexylmagnesium tetraethylaluminate, hexylmagnesium triethylpropylaluminate, hexylmagnesium triethylbutylaluminate, hexylma Gnessium triethylhexylaluminate, hexylmagnesium triethyloctylaluminate, hexylmagnesium tributylmethylaluminate, hexylmagnesium tributylethylaluminate, hexylmagnesium tetrabutylaluminate, hexylmagnesium tributylhexylaluminate, hexylmagnesium tributyloctylaluminate, and the like, and Magnesium bis (tetramethylaluminate,)
Magnesium bis (tetraethyl aluminate), magnesium bis (tetrapropyl aluminate), magnesium bis (tetrabutyl aluminate), magnesium bis (tetraisobutyl aluminate), magnesium bis (tetrahexyl aluminate), magnesium bis (tetraoctyl aluminum) Nate) and the like.

The compound consisting of these two kinds of organometallic compounds can be obtained by contacting the corresponding two kinds of organometallic compounds, and this contact is achieved by pentane, hexane, heptane, octane, decane, cyclopentane, cyclohexane. It can be carried out in an inert hydrocarbon solvent such as benzene, toluene or xylene. The contact temperature is -50 ℃ ~
200 ° C., preferably −20 to 100 ° C., more preferably 0 to 50 ° C., contact time is 0.05 to 200 hours,
It is preferably about 0.2 to 20 hours. Regarding the use of the organometallic compound according to the present invention, the above-mentioned organometallic compounds can be used alone or in combination of two or more kinds. The amount of the organic metal compound used is 1 mol of the metal atom in the transition metal compound,
The total amount of metal atoms in the organometallic compound is usually 1 to 200.
It is used in an amount of 0 mol, preferably 1 to 1500 mol.

In carrying out the present invention, the ethylene polymerization method may be a liquid phase polymerization method such as slurry polymerization or solution polymerization, or a gas phase polymerization method. The liquid phase polymerization method is usually carried out in a hydrocarbon solvent, and as the hydrocarbon solvent, propane, butane, isobutane, hexane, cyclohexane, heptane, benzene, toluene,
A single or a mixture of inert hydrocarbon solvents such as xylene is used. Further, the polymerization can be carried out in two or more stages by changing the reaction conditions. The polymerization temperature is generally from 0 to 3
The temperature is 00 ° C, and practically 20 to 200 ° C. The molecular weight of the obtained polymer can be adjusted by controlling the polymerization temperature or by allowing hydrogen and the like to coexist in the polymerization reactor.
Moreover, the molecular weight distribution of the polymer obtained by controlling the amount of the catalyst component can be controlled. Further, if necessary, propylene, 1-butene, 1-hexene, 4-methyl-1-
It is also possible to introduce α-olefins such as pentene and 1-octene alone or in combination into two or more kinds for copolymerization. The α-olefin content in the obtained ethylene-based polymer is preferably 20 mol% or less, and particularly preferably 15 mol% or less.

[0037]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The measurement methods used in Examples and Comparative Examples are shown below. (1) Pretreatment of polymer for measuring physical properties; using Plastograph manufactured by Toyo Seiki Co., Ltd., with 0.2 wt% of B225 manufactured by Ciba-Geigy Co., Ltd. added as an additive, and under nitrogen, 19
The mixture was kneaded at 0 ° C for 7 minutes. (2) Molecular weight and molecular weight distribution; measured by gel permeation chromatography (GPC) to determine the number average molecular weight (Mn) and the weight average molecular weight (Mw). The molecular weight distribution is M of Mw
It is represented by the ratio (Mw / Mn) to n, and the larger Mw / Mn, the wider the molecular weight distribution. The measurement conditions are as follows. -Device: WATERS 150C model-Column: Shodex-HT806M-Solvent: 1,2,4-trichlorobenzene-Temperature: 135 ° C-Sample concentration: 2 mg / 5 ml-Universal evaluation using monodisperse polystyrene fraction (3) Melt flow Rate: According to JIS-K-6760, the measured value at a temperature of 190 ° C. and a load of 21.6 Kg is shown as HLMFR. (4) Density; measured according to JIS-K-6760. The ethylene (co) polymerization conditions (catalyst species, catalyst amount, polymerization temperature, hydrogen / ethylene weight ratio) in Examples are shown in Tables 1 and 2.

The compounds used in the examples were obtained as follows. (5) The transition metal compound dimethylsilylene (tert-butylamide) (tetramethylcyclopentadienyl) titanium dichloride having a group having a conjugated π electron as a ligand can be prepared by the method described in JP-A-3-163088.
(Cyclopentadienyl) (N, N ^, -bis (trimethylsilyl) benzamidinato) zirconium dichloride is described in J. Org Chem. , 491 , 153 (19
95). Bis (methylcyclopentadienyl) zirconium dichloride, bis (n-propylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl)
Zirconium dichloride, ethylene bis (indenyl)
As zirconium zirlolide, a product manufactured by Witco was used. (6) Organic compound n-butyllithium is Aldrich
As for other products such as n-butylethylmagnesium and triisobutylaluminum, those manufactured by Toso Akzo Co., Ltd. were used.

(Preparation of carrier catalyst component) 15 g of silica (grade 952) manufactured by DAVISON was placed in a flask,
Chromium acetate manufactured by Wako Pure Chemical Industries, Ltd. dissolved in 100 ml of distilled water was added so that the amounts of supported chromium atoms were as shown in Table 1, and the mixture was stirred at room temperature for 30 minutes. Distilled water was removed by evaporation from the obtained slurry at 110 ° C. The obtained powder was put into a cylindrical firing electric furnace (diameter 38 mm, with perforated plate), and first, using nitrogen gas, a linear velocity of 4 cm /
The temperature was raised at a temperature rise rate of 60 ° C./hr at a flow rate of sec. 3
When the temperature reached 50 ° C., nitrogen was changed to air, the mixture was baked at this temperature for 18 hours while flowing at the same linear velocity, then the atmosphere was changed to nitrogen and the temperature was lowered to room temperature to obtain a carrier catalyst component. (Preparation of Solid Catalyst Component (1)) 3 g of the carrier catalyst component obtained above and 35 ml of toluene were added to a flask purged with nitrogen to form a slurry. Toluene slurry of 1.1 mol / liter methylaluminoxane manufactured by Tosoh Akzo Co. was added to this slurry so that the molar ratios of aluminum atoms in methylaluminoxane and chromium atoms in the carrier component were the values shown in Table 1, respectively. The mixture was stirred at 40 ° C for 2 hours. The solvent was removed under vacuum to obtain a solid catalyst component (1).

(Examples 1 to 3) Ethylene Polymerization In a 1.5 liter autoclave substituted with nitrogen, 600 ml of isobutane and solid catalyst component (1) shown in Table 1 in advance.
Was charged and the temperature was raised to the polymerization temperature. Then, a hydrogen / ethylene mixed gas having a mixing ratio shown in Table 2 was added at a partial pressure of 1
Polymerization was initiated by press-fitting until the pressure reached 4.0 kg / cm ² .
Then, the mixed gas partial pressure was maintained at 14.0 kg / cm ^2, and when the induction period of the solid catalyst component (1) was completed, 0.5 mmol / liter of a hexane solution of the transition metal compound shown in Table 1 was added. Polymerization was performed for 30 minutes, and then the content gas was discharged to the outside of the system to terminate the polymerization. When the inside of the autoclave was checked after completion of the reaction, a polymer was obtained without fouling. Table 2 shows the results.

(Examples 4 to 6) Polymerization of ethylene In a nitrogen-substituted 1.5 liter autoclave, Table 1 was prepared in advance.
The solid catalyst component (1) shown in (1) and 600 ml of isobutane were charged and the temperature was raised to the polymerization temperature. Then, a hydrogen / ethylene mixed gas having a mixing ratio shown in Table 2 was added at a partial pressure of 14.0 k.
Polymerization was initiated by press-fitting until g / cm ² . The mixed gas partial pressure was maintained at 14.0 kg / cm ² , and 0.5 mm at the end of the induction period of the solid catalyst component (1).
ol / l transition metal compound in hexane and 0.
Hexane solution of 5 mol / l organometallic compound 1.
2 ml (0.6 mmol) was added and polymerization was performed for 30 minutes. Then, the polymerization was terminated by discharging the content gas out of the system. When the inside of the autoclave was checked after completion of the reaction, a polymer was obtained without fouling. Table 2 shows the results. (Example 7) Copolymerization of ethylene and 1-hexene A solid catalyst component (1) shown in Table 1 and 600 ml of isobutane were placed in a 1.5-liter autoclave substituted with nitrogen.
Was charged and the temperature was raised to the polymerization temperature. Then, a mixed gas of 1 / hexene and hydrogen / ethylene having a mixing ratio shown in Table 2 was injected until the partial pressure of the mixed gas reached 14.0 kg / cm ² to start polymerization. Mixed gas partial pressure 14.0 kg
/ Cm ² and when the induction period of the solid catalyst component (1) was completed, 0.5 mmol / liter of the hexane solution of the transition metal compound shown in Table 1 and 0.5 mo
1.2m of hexane solution of 1 / l of organometallic compound
1 (0.6 mmol) was added and polymerization was carried out for 30 minutes. Then, the polymerization was terminated by releasing the content gas out of the system. When the inside of the autoclave was checked after completion of the reaction, a copolymer was obtained without fouling. Table 2 shows the results.

Comparative Example 1 Ethylene was polymerized in the same manner as in Example 1 except that the chromium-free solid catalyst component was used. Table 2 shows the results. (Comparative Example 2) Ethylene was polymerized in the same manner as in Example 1 except that the transition metal compound was not used. The results are shown in Tables 1 and 2.

(Comparative Example 3) Preparation of solid catalyst component (2) To a flask purged with nitrogen, 3 g of the carrier catalyst component and 35 ml of toluene were added to prepare a slurry. Toluene slurry of 1.1 mol / liter methylaluminoxane manufactured by Tosoh Akzo Co. was added to this slurry so that the molar ratio of aluminum atoms in methylaluminoxane to chromium atoms in the carrier component was the value shown in Table 1. The mixture was stirred at room temperature for 1 hour. Next, 0.5 mmol / liter of a hexane solution of the transition metal compound shown in Table 1 was added to this slurry, and the mixture was stirred at room temperature for 1 hour. The solvent was removed under vacuum to obtain a solid catalyst component (2). Polymerization of ethylene Into a 1.5 liter autoclave substituted with nitrogen, 600 ml of isobutane and the solid catalyst component (2) shown in Table 1 in advance.
Was charged and the temperature was raised to the polymerization temperature. Then, a hydrogen / ethylene mixed gas having a mixing ratio shown in Table 2 was added at a partial pressure of 1
Polymerization was initiated by press-fitting until the pressure reached 4.0 kg / cm ² .
Thereafter, the mixed gas partial pressure was maintained at 14.0 kg / cm ² and polymerization was carried out for 30 minutes. Then, the content gas was discharged to the outside of the system to terminate the polymerization. When the inside of the autoclave was checked after completion of the reaction, the polymer was attached in the form of a sheet to the inner wall of the autoclave and the stirring blades,
Fouling was seen. The results of the obtained polymer are shown in Table 2.
Shown in

[0044]

[Table 1]

[0045]

[Table 2]

Industrial Applicability According to the present invention, an ethylene polymer having a wide molecular weight distribution can be efficiently produced without fouling and is extremely valuable industrially.

[Brief description of the drawings]

FIG. 1 is a flow chart for preparing an ethylene-based polymerization catalyst according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shintaro Inazawa Oita City, Oita Prefecture Nakanosu 2, Nihon Polyolefin Co., Ltd. Oita Research Center

Claims (7)

[Claims] 1. A solid catalyst component carrying an aluminoxane is contacted with a transition metal compound having a group having a conjugated π electron as a ligand, which is obtained by calcining a carrier carrying a chromium compound. Ethylene polymerization catalyst. 2. A carrier catalyst component obtained by calcining a carrier carrying a chromium compound, a solid catalyst component carrying an aluminoxane, and a polymerization catalyst of 0.1 mol per mol of chromium atom in the solid catalyst component during polymerization. An ethylene-based polymerization catalyst obtained by contacting with a transition metal compound having a ligand having a conjugated π electron as a ligand, in the range of 01 mmol to 1000 mol. 3. A chromium compound is supported on a carrier in an amount of 0.01 to 5% by weight as chromium atoms, and then 300 to 1000.
The catalyst for ethylene polymerization according to claim 1 or 2, which is a carrier catalyst component calcined in a dry gas containing oxygen for 1 to 48 hours. 4. The ethylene-based polymerization catalyst according to claim 1, wherein the solid catalyst component has an aluminum / chromium molar ratio of 5 to 500 mol. 5. After supporting a chromium compound on a carrier, 30
A solid catalyst component was prepared by supporting an aluminoxane on a carrier catalyst component calcined in a dry gas containing oxygen at 0 to 1000 ° C. for 1 to 48 hours, and then, immediately before the initiation of polymerization, chromium atoms in the solid catalyst component. A method for producing an ethylene-based polymerization catalyst, which comprises contacting a transfer metal compound having a group having a conjugated π-electron of 0.01 mmol to 1000 mol with respect to 1 mol as a ligand. 6. An ethylene-based polymerization catalyst obtained by bringing an organometallic compound into contact with the ethylene-based polymerization catalyst according to any one of claims 1 to 4. 7. The catalyst for ethylene polymerization according to claim 1, wherein ethylene alone as a monomer or ethylene containing an α-olefin is used as a monomer.
A method for producing an ethylene-based polymer in the range of 300 ° C.