JP2000154209A - Manufacture of olefin polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance polymerization activity and obtain a polymer having higher molecular weight by adding an ester compound to a polymerization system with a catalyst comprising a metallocene-supported type catalyst as a major component, the molar ratio of the ester compound to a transition metal of the catalyst being in a specific range. SOLUTION: A reaction product obtained by reacting a metallocene compound with aluminoxane in a hydrocarbon solvent is supported on an inorganic or organic porous fine particle carrier having particle diameter of 1-500 μm, specific surface area of 50-1,000 m2/g and fine porosity volume of 0.3-2.5 m3/g and an olefin such as propylene is added for preliminary polymerization to prepare an activated metallocene-supported type catalyst. Further the catalyst and an organic aluminium compound are added to a hydrocarbon solvent to form a slurry to which are added an ester compound represented by formula Ra-COO-Rb such as methyl para-toluylate, the molar ratio of the ester compound to a transition metal being in the range of 0.001-50, and a predetermined amount of an olefin to give an olefin polymer wherein Ra and Rb are 1-20C aliphatic hydrocarbons.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an olefin polymer using a metallocene-supported catalyst, and more particularly, to an olefin polymerization reaction system using an olefin polymerization catalyst containing a metallocene-supported catalyst as a main component. ,
The present invention relates to a method for producing a novel olefin polymer in which an olefin is polymerized in the presence of a small amount of an ester compound.

[0002] An organic complex of a Group IVA transition metal, for example, an olefin polymerization catalyst comprising a metallocene compound such as zirconocene, titanocene, hafnocene and an organometallic compound such as aluminoxane, and the production of an olefin polymer using these catalysts The method is disclosed in
Many proposals have been made in, for example, Japanese Patent Application Laid-Open No. 19309, and it is known that these catalysts have high olefin polymerization activity.

[0003] Further, various supported catalysts in which at least one component of a metallocene compound and an aluminoxane are supported on a porous inorganic oxide carrier such as silica, alumina and silica-alumina, and a slurry polymerization system or gas catalyst using the same. Many methods for polymerizing olefins in a phase polymerization system have been proposed in JP-A-60-35005 and others. For example, as disclosed in JP-A-61-108610 and JP-A-61-296008, an olefin is polymerized in the presence of a metallocene-supported catalyst in which a metallocene compound and an aluminoxane are supported on a carrier such as an inorganic oxide. A method is disclosed. Further, JP-A-63-28
No. 0703 describes a method for pre-activating a catalyst by prepolymerizing an olefin in the presence of a carrier such as a zirconocene compound, an aluminoxane, an organoaluminum compound and silica.

In addition, in the conventional propylene polymerization using a Ziegler-Natta catalyst, the presence of an ester compound as a co-catalyst in a polymerization reaction system for the purpose of improving the stereoregularity of the obtained propylene polymer is described as follows. Polypropylene Handbook "(Industry Research Council, p. 39)
Others are known from many articles. However, there is no literature reporting the action of an ester compound in an olefin polymerization reaction system using a metallocene catalyst.

[0005]

[Problems to be solved by the invention] Macromol. Rapid Comm
un.15, 593-600 (1994) reported that when propylene is polymerized in an olefin polymerization system in the presence of a metallocene-supported catalyst comprising a metallocene compound, an aluminoxane and a carrier as described above, the metallocene It is stated that the propylene polymerization activity of the metallocene compound is lower than when no compound or the like is supported. In the olefin polymerization using a metallocene-supported catalyst, the present invention improves the olefin polymerization activity of the metallocene-supported catalyst, which tends to decrease, maintains the olefin polymerization activity at a high level, and produces an olefin polymer in which a higher molecular weight olefin polymer is obtained. The aim is to provide a method.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, by adding a small amount of an ester compound to an olefin polymerization system using a metallocene supported catalyst, The present inventors have found that the olefin polymerization activity of a metallocene-supported catalyst is improved, and a higher molecular weight olefin polymer is produced, thereby completing the present invention.

According to the present invention, a polymerization reaction system for polymerizing an olefin using an olefin polymerization catalyst having a metallocene-supported catalyst as a main component is represented by the following general formula (1): ^Ra- COO- ^Rb (1) (Wherein, R ^a and R ^b each independently represent a carbon number of 1 to
At least one ester compound represented by an aliphatic hydrocarbon group of 20 or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may be substituted with the aliphatic hydrocarbon group), A method for producing an olefin polymer, characterized in that the transition metal molar ratio in the catalyst is in the range of 0.001 to 50.

[0008]

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "polymerization"
Is used to mean homopolymerization of one kind of monomer, random copolymerization and block copolymerization of two or more kinds of monomers. That is, the term "olefin polymer"
It means any of a homopolymer of one kind of olefin, a random copolymer of two or more kinds of olefins, and a block copolymer. The term “polymerization reaction system” means a reaction system for polymerizing one or more olefin monomers,
The polymerization reaction system includes a slurry polymerization system using a reaction solvent such as an aliphatic hydrocarbon, a bulk polymerization system using an olefin monomer itself as a reaction solvent, and a gas phase polymerization system for polymerizing an olefin in a gas phase. The term `` polymerization medium '' refers to the sum of the reaction solvent and monomer present as a liquid phase when the polymerization reaction system is a slurry polymerization system, the monomer existing as a liquid phase when a bulk polymerization system is used, and a gas phase polymerization system. In the case of, it means each monomer present as a gas phase.

The above-mentioned olefins include linear monoolefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene; 3-methyl-1-butene, Branched-chain monoolefins such as -methyl-1-pentene and 2-methyl-1-pentene; cyclopentene, cyclohexene, norbornene, 5-methyl-2-norbornene, 5-ethyl-2
Cyclic olefins such as -norbornene, phenylnorbornene and indanylnorbornene; 1,3-butadiene, isoprene, 1,4-hexadiene, 1,7-octadiene, 1,9-decadiene, 4-methyl-1,4-hexadiene, Linear polyenes such as 5-methyl-1,4-hexadiene and 7-methyl-1,6-octadiene; dicyclopentadiene, 5-methylene-2-norbornene,
Cyclic polyenes such as 5-ethylidene-2-norbornene; styrenes such as styrene, vinylnaphthalene and α-methylstyrene; 4-trimethylsiloxy-1,6-
Heptadiene, 5- (N, N-diisopropylamino)
And derivatives such as -1-pentene and vinyl compounds such as vinylcyclohexane, vinyl chloride, methyl methacrylate and ethyl acrylate.

In the present invention, the polymerization reaction system is a homopolymerization system of the above-mentioned olefins, particularly ethylene, propylene and 1-butene using an olefin polymerization catalyst having a metallocene supported catalyst as a main component, and two types thereof. The copolymerization reaction system described above, more specifically, a homopolymerization system of propylene and a random or block copolymerization reaction system of propylene with the olefin other than propylene, preferably ethylene and / or 1-butene.

These polymerization reaction systems include aliphatic hydrocarbons such as butane, pentane, hexane, heptane and isooctane; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane; and aromatic hydrocarbons such as toluene, xylene and ethylbenzene. Slurry polymerization system for polymerizing olefins in inert solvents such as hydrocarbons, gasoline fractions and hydrogenated diesel oil fractions, bulk polymerization systems using olefins themselves as solvents, and gas phase polymerization systems for polymerizing olefins in the gas phase Or a polymerization reaction system combining two or more of these polymerization systems, but is preferably a slurry polymerization system using an aliphatic hydrocarbon such as hexane or heptane as a reaction solvent.

In the present invention, the ester compound present in the polymerization reaction system is at least one kind represented by the following general formula (1). R ^a —COO—R ^b (1) In the formula, R ^a and R ^b each independently have 1 to 2 carbon atoms.
0 aliphatic hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, octadecyl, etc. A linear or branched alkyl group having 1 to 20 carbon atoms, an alkenyl group such as vinyl, allyl, propenyl, isopropenyl, and butenyl; a cyclopropyl, cyclopentyl, and cyclohexyl which may be substituted with the alkyl group and the alkenyl group; And an aromatic hydrocarbon group having 6 to 20 carbon atoms, for example, an aromatic hydrocarbon group such as phenyl, naphthyl, and benzyl which may be substituted with the aliphatic hydrocarbon group. Represents

As the ester compound, an ester compound represented by the above general formula can be used without any particular limitation. For example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, isopentyl acetate, benzyl acetate,
Phenyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, ethyl stearate, ethyl phenylacetate,
Examples include ethyl benzoate, ethyl isobutyrate, ethyl trimethyl acetate, methyl oleate, methyl paratoluate, ethyl paratoluate, and the like. Methyl paratoluate and ethyl paratoluate are preferably used.

The amount of the ester compound to be present in the polymerization reaction system is 0.001 to 50, preferably 0.01, as a molar ratio of the ester compound to the transition metal in the metallocene-supported catalyst.
To 30, more preferably 0.1 to 10.
Usually, the ester compound is added to the polymerization reaction system in an amount of 1 × 10 ⁻⁸ to 1 × 10 ⁻⁴ mol, preferably 1 × 10 ⁻⁴ mol per liter of the polymerization medium.
It is present in the range of ^10-7 to 1 ^10-5 mol. If the amount of the ester compound in the polymerization reaction system is too small, the effect of improving the olefin polymerization activity of the metallocene-supported catalyst becomes insufficient, while if it is excessive, the catalyst activity itself of the metallocene compound is lost. Live.

In the present invention, the catalyst for olefin polymerization comprises a metallocene-supported catalyst as a main component and a combination thereof with an organoaluminum compound. The metallocene-supported catalyst may be any one of solid fine particles in which a metallocene compound and an aluminoxane or a reaction product thereof are supported on a particulate carrier, and any known metallocene-supported catalyst can be used. .

For example, a metallocene compound is added to a silica / toluene slurry in the order of aluminoxane, or vice versa, and the metallocene compound and the aluminoxane are supported on silica. A mixed solution of a metallocene compound and an aluminoxane is added to and brought into contact with a solid particle obtained by supporting the metallocene compound and aluminoxane on silica obtained by reacting the metallocene compound with the aluminoxane in the presence of inorganic metal oxide fine particles. The reaction product of the metallocene compound and the aluminoxane is supported on the obtained inorganic metal oxide fine particles, and the inorganic metal oxide fine particles are added while the metallocene compound and the aluminoxane are reacted in an inert solvent. Contact, then inert solution Reaction product of the metallocene compound and the aluminoxane can be cited supported metallocene catalyst such as supported solid fine particles on the inorganic metal oxide particles obtained by evaporating off the.

Preferably, a metallocene-supported catalyst preactivated by prepolymerizing a small amount of an olefin in the presence of the metallocene-supported catalyst is used. The olefin to be prepolymerized may be any of the olefins exemplified above, but is preferably ethylene, propylene, 1-butene and a mixed olefin of two or more thereof.

The particulate carrier constituting the metallocene-supported catalyst has a particle diameter of 1 to 500 μm, preferably 5 to 500 μm.
It is a 300 μm granular or spherical inorganic or organic fine particle. These particulate carriers have a specific surface area of 50 to
1,000 m ² / g, preferably in the range of 100~700m ² / g, and is preferably a pore volume of a porous fine particles in the range of 0.3~2.5m ³ / g.

As the inorganic fine particle carrier, a metal oxide,
For example, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO
₂ , these composite oxides or mixtures thereof, for example, SiO ₂ —Al ₂ O ₃ , SiO ₂ —MgO, SiO ₂ —
Fine particles such as TiO ₂ , SiO ₂ —Al ₂ O ₃ —MgO are exemplified. Preferred supports are SiO ₂ , Al ₂ O ₃ and M
Fine particles containing at least one selected from the group consisting of gO as a main component, more preferably fine particles containing SiO ₂ or Al ₂ O ₃ as a main component. Especially silica (S
iO ₂ ) is preferred.

Prior to use, these inorganic fine particle carriers are usually used at 100 to 1,000 ° C., preferably at 300 to 9 ° C.
Firing at 00 ° C, particularly preferably 400 to 900 ° C, for 1 to 40 hours. The inorganic fine particle carrier after calcination has a surface adsorbed water amount of 0.1% by weight or less, preferably 0.01% by weight or less, and a surface hydroxyl group content of 1.0% by weight or more, preferably 1.5 to 4.0%. %, More preferably in the range of 2.0-3.5% by weight. Instead of firing, for example, it may be used after being chemically treated with an organic aluminum compound, SiCl ₄ , chlorosilane, or the like.

Examples of the organic fine particle carrier include organic polymer fine particles, for example, polyolefin fine particles such as polyethylene, polypropylene, poly-1-butene and poly-4-methyl-1-pentene, and polystyrene fine particles.

The metallocene compound constituting the metallocene supported catalyst is a transition metal, for example, Y, Sm, Ti, Z
r, Hf, V, Nb, Ta, Cr, etc., preferably T
Group IVA transition metals such as i, Zr, Hf, and the like, have π-electron conjugated ligands, such as unsubstituted or substituted cyclopentadienyl groups, unsubstituted or substituted indenyl groups, indenyl hydride groups, unsubstituted or substituted fluorenyl groups. Any organic complex to which a ligand having an η-cyclopentadienyl structure such as described above is bonded and which exhibits olefin polymerization activity can be used without particular limitation.

A preferred metallocene compound is represented by the following general formula:
It is at least one kind of the compound represented by (2).

Embedded image

In the formula, M represents a transition metal selected from the group consisting of Ti, Zr and Hf. X is each independently hydrogen, a halogen atom such as F, Cl, Br, I or a C _{1 to} C ₂₀ hydrocarbon group, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t
tert-butyl, sec-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl,
Chain alkyl group C ₁ -C _20, such as octadecyl, cyclopropyl, cyclopentyl, cyclohexyl, C ₃ -C _{2 0} cycloalkyl group substituted with cycloheptyl, and the like, and further wherein the chain alkyl groups, phenyl, naphthyl And C ₆ -C ₂₀ aryl groups further substituted with the above alkyl groups, benzyl and the like, and C ₇ -C ₂₀ aralkyl groups further substituted with the above alkyl groups, alkoxy, alkoxyalkyl, aryloxy, aralkyloxy And C _{1 to} C ₂₀ oxygen-containing hydrocarbon groups, and C _{1 to} C ₂₀ silicon-containing hydrocarbon groups such as trialkylsilyl, triphenylsilyl and trialkylsilylalkyl. Preferably a halogen atom or C
Chain alkyl group having ₁ -C _20, more preferably a chain alkyl group of Cl or C ₁ -C _4.

(C ₅ H _4-m R ¹ _m ) and (C ₅ H _4-n R ² _n )
Represents a substituted cyclopentadienyl group, wherein m and n are integers of 1 to 3, each of R ¹ and R ²
Each independently represents a C _{1 to} C ₂₀ hydrocarbon group or a silicon-containing hydrocarbon group, or two of R ¹ and / or ^two of R ² together form a cyclopentadienyl ring Represents a divalent hydrocarbon group capable of forming a saturated or unsaturated ring having 4 to 8 ring carbon atoms by bonding to two adjacent carbons, and the formed ring is represented by R ¹ and R ² It may be further substituted. Preferred R ¹ and R ² are C
_A linear alkyl group of ₁ to ₄ carbon atoms, a phenyl group, a naphthyl group, and a divalent group capable of forming an indenyl group or a fluorenyl group by bonding to two adjacent carbons on a cyclopentadienyl ring; The formed indenyl or fluorenyl group is a C ₁ -C ₄ chain alkyl group, phenyl group,
It may be further substituted with a naphthyl group.

Q is a divalent group capable of linking the two substituted cyclopentadienyl groups, for example, methylene, dimethylmethylene, dichloromethylene, ethylene, tetramethylethylene, unsubstituted or substituted cyclohexylene, unsubstituted or Divalent hydrocarbon groups such as substituted phenylene, silylene groups such as dimethylsilylene and dichlorosilylene, divalent germanium-containing groups such as dimethylgermylene and dichlorogermylene (germylene group), and divalent such as dimethylstannylene And the like, preferably a divalent hydrocarbon group, a silylene group or a germylene group, more preferably a dimethylsilylene or dimethylgermylene group.

A preferred metallocene compound is represented by the general formula
In (2), the substitution positions of R ¹ and R ^{2 on} the ^two cyclopentadienyl rings are arranged so that there is no symmetry plane containing M, and more preferably, at least one of R ¹ and R ² is cycloalkyl. It is a chiral metallocene compound present on the carbon adjacent to the carbon connected to Q of the pentadienyl ring.

As the metallocene compound represented by the general formula (2), for example, dimethylsilylene (3-t-butylcyclopentadienyl) (fluorenyl) zirconium dichloride, dimethylgermylene (3-t-butylcyclopentadienyl) Enyl) (fluorenyl) zirconium dichloride, ethylenebis (indenyl) zirconium dimethyl, ethylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dimethyl, dimethylsilylenebis (indenyl) zirconium dichloride, dimethylgermylenebis (indenyl) zirconium Dichloride, ethylenebis (tetrahydroindenyl) zirconium dimethyl, ethylenebis (tetrahydroindenyl) zirconium dichloride, dimethylsilyl Nbisu (tetrahydroindenyl)
Zirconium dimethyl, dimethylsilylenebis (tetrahydroindenyl) zirconium dichloride, dimethylgermylenebis (tetrahydroindenyl) zirconium dichloride, ethylenebis (2-methyl-4,5,6,
7-tetrahydroindenyl) zirconium dichloride, dimethylsilylenebis (2-methyl-4,5,6,7)
-Tetrahydroindenyl) zirconium dimethyl, dimethylsilylenebis (2-methyl-4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylgermylenebis (2-methyl-4,5,6,7-tetrahydroindene Nyl) zirconium dichloride, dimethylsilylenebis (2-methyl-4-phenylindenyl)
Zirconium dimethyl, dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylgermylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl-4-naphthylindene) Nil) zirconium dimethyl, dimethylgermylene bis (2-methyl-4-naphthylindenyl) zirconium dichloride, dimethylsilylenebis (2-methyl-4,5-benzoindenyl) zirconium dimethyl, dimethylsilylenebis (2-methyl- 4,5-benzoindenyl) zirconium dichloride, dimethylgermylene bis (2-methyl-4,5-benzoindenyl) zirconium dichloride, dimethylsilylenebis (2-ethyl-4-phenylindenyl) zirconium Dimethyl, dimethylsilylenebis (2-ethyl-4-phenylindenyl) zirconium dichloride, dimethylgermylenebis (2-ethyl-4-phenylindenyl) zirconium dichloride, dimethylsilylenebis (2-methyl-4,6-diisopropyl) Indenyl) zirconium dimethyl, dimethylsilylenebis (2-methyl-4,6-diisopropylindenyl) zirconium dichloride, dimethylgermylenebis (2-methyl-4,6-diisopropylindenyl) zirconium dichloride, dimethylsilylene (2, 4-dimethylcyclopentadienyl) (3 ′, 5 ′
-Dimethylcyclopentadienyl) zirconium dimethyl, dimethylsilylene (2,4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride, dimethylgermylene (2,4-dimethylcyclopenta Dienyl) (3 ', 5'
-Dimethylcyclopentadienyl) zirconium dimethyl, dimethylsilylene (2,3,5-trimethylcyclopentadienyl) (2 ', 4', 5'-trimethylcyclopentadienyl) zirconium dimethyl, dimethylsilylene (2,3 , 5-trimethylcyclopentadienyl)
(2 ', 4', 5'-trimethylcyclopentadienyl)
Zirconium dichloride, dimethylgermylene (2,3,
5-trimethylcyclopentadienyl) (2 ′, 4 ′,
5'-trimethylcyclopentadienyl) zirconium dichloride and the like, and compounds obtained by replacing zirconium in the above-mentioned exemplified compounds with titanium or hafnium.

These metallocene compounds have a dl form of 10
Most preferably, it is 0% chiral compound,
A mixture of the dl-form and the meso-form containing the meso-form in the range of 0% or less can be used as long as it does not significantly affect the physical properties of the olefin polymer obtained using the same.

The most preferred metallocene compounds in the present invention are dimethylsilylene (2,3,5-trimethylcyclopentadienyl) (2 ', 4', 5'-trimethylcyclopentadienyl) zirconium dichloride and dimethylsilylenebis (2 -Methyl-4-phenylindenyl) zirconium dichloride.

The aluminoxane constituting the metallocene-supported catalyst is an organoaluminum compound polymer represented by the following general formula (3) and / or an organoaluminum compound polymer represented by the following general formula (4).

Embedded image

In the formula, each of R ³ independently represents C _1-
C ₆ , preferably C ₁ -C ₄ hydrocarbon groups, for example, alkyl groups such as methyl group, ethyl group, propyl group, butyl group, isobutyl group, pentyl group, hexyl group, allyl group, 2-methylallyl group, A propenyl group, an isopropenyl group, a 2-methyl-1-propenyl group, an alkenyl group such as a butenyl group, a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cycloalkyl group such as a cyclohexyl group, and an aryl group such as phenyl; Preferably it is an alkyl group, more preferably a methyl group. q
Is an integer of 4 to 30, preferably 6 to 30, and more preferably 8 to 30.

As the aluminoxane, a commercially available product can be used, or it may be prepared and used under various known conditions, for example, by the following method. 1) A method in which a trialkylaluminum, for example, trimethylaluminum, triisobutylaluminum or a mixture thereof is directly reacted with water in an organic solvent such as toluene or ether in the presence of an acid or alkali catalyst. 2) A method of reacting a trialkylaluminum such as trimethylaluminum, triisobutylaluminum or a mixture thereof with a salt having water of crystallization such as copper sulfate hydrate or aluminum sulfate hydrate. 3) A method in which water impregnated in silica gel or the like is reacted with a trialkylaluminum, for example, trimethylaluminum or triisobutylaluminum, singly, simultaneously or sequentially.

In a preferred embodiment of the present invention, (a) a step of reacting a metallocene compound with an aluminoxane in an aromatic hydrocarbon solvent to produce a reaction product; (b)
Contacting the reaction product with the particulate carrier at a temperature of 85 to 150 ° C. in the presence of an aromatic hydrocarbon solvent to form a solid product having the reaction product supported on the particulate carrier And (c) removing the solid product from -50 to
A step of washing with an aliphatic hydrocarbon solvent at a temperature of + 30 ° C., and a metallocene-supported catalyst comprising a particulate carrier and a reaction product of a metallocene compound and an aluminoxane supported on a particulate carrier. used. More preferably, following the step (c), (d)
A step of introducing an olefin into a slurry in which the solid fine particles are dispersed in an aliphatic hydrocarbon solvent to perform prepolymerization, and supporting the generated polyolefin on the solid fine particles; A type catalyst is used.

The aromatic hydrocarbon solvent used for the reaction between the metallocene compound of step (a) and the aluminoxane and the contact of the reaction product of step (b) with the inorganic fine particle carrier include, for example, benzene, toluene, Xylene, cumene and the like, preferably toluene used as a commercially available aluminoxane solvent as it is, or an aromatic hydrocarbon solvent such as toluene is further added thereto.

Further, in place of the aromatic hydrocarbon solvent,
Solvents inert to metallocene compounds, aluminoxanes and their reaction products, for example, cycloaliphatic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, cyclooctane, and the aromatic and alicyclic hydrocarbons are halogens. Substituted halogenated aromatic hydrocarbons, halogenated alicyclic hydrocarbons, mixed solvents thereof and mixed solvents thereof with aromatic hydrocarbons, and ethers such as ethyl ether and tetrahydrofuran can also be used.

On the other hand, the aliphatic hydrocarbon solvent used in the washing of the solid product in the step (c) and the prepolymerization of the olefin in the step (d) includes, for example, butane, tetramethylbutane, pentane, ethylpentane, trimethyl Pentane,
Hexane, methylhexane, ethylhexane, dimethylhexane, heptane, methylheptane, octane, nonane, decane, hexadecane, octadecane and the like and a mixed solvent thereof, preferably n-pentane, isopentane, n-hexane, n-heptane And a mixed solvent thereof.

In the step (a), 10 to 1,000 mol, preferably 20 to 500 mol, of aluminoxane as an aluminum atom per 1 mol of the metallocene compound (1 mol of the transition metal) is added in the aromatic hydrocarbon solvent to form
A reaction product of the metallocene compound and the aluminoxane is obtained by reacting at a temperature of 50 to 100 ° C., preferably 0 ° C. to 50 ° C. for 1 minute to 10 hours, preferably 3 minutes to 5 hours with stirring. Can be The use of an aromatic hydrocarbon solvent is preferable in that the reaction proceeds uniformly and efficiently. The amount of the aromatic hydrocarbon solvent used is not particularly limited, but is usually 10 to 10 per mol of the metallocene compound.
2,000 liters, preferably about 10 to 1,000 liters.

In the subsequent step (b), the reaction product obtained in the step (a) and the inorganic particulate carrier are usually dissolved in the presence of the aromatic hydrocarbon solvent used as the reaction solvent in the step (a). , 85-150 ° C, preferably 90-130 ° C, more preferably 95-120 ° C for 5 minutes
By contacting for 100 hours, preferably 10 minutes to 50 hours, the reaction product is supported on the inorganic fine-particle carrier, and a solid product is obtained. In this catalytic reaction, an aromatic hydrocarbon solvent may be added as needed.

The contact ratio between the reaction product and the inorganic particulate carrier is 1 to 1,000 kg, preferably 5 kg, per 1 mol of the transition metal in the reaction solution obtained in the step (a). ~ 500 kg. The amount of the aromatic hydrocarbon solvent used is 10 to 10 per mol of transition metal in the reaction solution.
2,000 liters, preferably 10-1,000 liters.

The temperature of the contact between the reaction product and the inorganic fine particle carrier is an important factor. By bringing the reaction product into contact within the above-mentioned temperature range, the obtained metallocene-supported catalyst has a high olefin polymerization activity, A high bulk specific gravity and good particle properties of the olefin polymer obtained by using the type catalyst for the polymerization of olefin are achieved.

In the following step (c), the solid product obtained in the step (b) is treated with an aliphatic hydrocarbon solvent in the range of -50 to
The olefin polymerization comprising solid fine particles wherein the reaction product is supported on an inorganic particulate carrier by washing under a temperature condition of + 30 ° C, preferably -30 to 0 ° C, more preferably -20 to 0 ° C. A metallocene-supported catalyst suitable as a main component for use is obtained.

In the step (c), for example, after completion of the step (b), the aromatic hydrocarbon solvent is separated from the reaction solution slurry containing the solid product by filtration, centrifugation, decantation or the like. After the completion of the step (b), adding an aliphatic hydrocarbon without separating an aromatic hydrocarbon solvent from a reaction solution slurry containing a solid product, and adding an aromatic hydrocarbon. After separating the mixed solvent of the hydrogen solvent and the aliphatic hydrocarbon, a method of washing the solid product using the aliphatic hydrocarbon, or the like can be employed.

The washing conditions for the solid product are as follows: 1-500 mg of aliphatic hydrocarbon per 1 kg of inorganic particulate carrier per washing.
Using 1 liter, preferably 10 to 100 liters, the washing is repeated until the metallocene compound is no longer eluted in the washed aliphatic hydrocarbon. It is sufficient to wash at least two times, usually four times or more, but not limited thereto.

The washing temperature condition in the step (c) is an important factor similarly to the contact temperature condition between the reaction product and the inorganic fine particle carrier, and the metallocene carrier obtained by washing in the above temperature range is obtained. The high olefin polymerization activity of the type catalyst and the high bulk specific gravity and good particle properties of the olefin polymer obtained by using the metallocene-supported catalyst for olefin polymerization are achieved.

In the present invention, the metallocene-supported catalyst prepared by the above-described method may be used as a main component of the olefin polymerization catalyst, but preferably the step (d) is followed by the step (d). A further practiced and preactivated metallocene supported catalyst is used.

In the step (d), the slurry is obtained by dispersing the solid fine particles in the final step of the step (c) as a slurry in which the solid fine particles are dispersed in the aliphatic hydrocarbon, without separating the solid fine particles from the aliphatic hydrocarbon. The solid fine particles may be used after separation, and then redispersed in a similar aliphatic hydrocarbon. Preliminary polymerization of olefins can be performed in a liquid phase using the olefin to be polymerized itself as a solvent or in a gas phase without using a solvent, but the polymerization of a small amount of olefins is controlled and promoted uniformly. It is preferably carried out in the presence of an aliphatic hydrocarbon.

In step (d), 0.005 to ⁵ m ^{3 of} aliphatic hydrocarbon, preferably 0.0, per kg of solid fine particles.
An olefin is used in an amount of 0.01 to 1,000 in a slurry in which solid fine particles using 1 to 1 m ³ are dispersed in an aliphatic hydrocarbon.
kg, preferably 0.1-500 kg, -50 ~
The prepolymerization reaction of the olefin is carried out at 100 ° C., preferably 0 to 50 ° C., for 1 minute to 50 hours, preferably 3 minutes to 20 hours.

In the olefin prepolymerization reaction,
Since the reaction product of the metallocene compound and the aluminoxane is supported on the solid fine particles, it is not particularly necessary to newly add a cocatalyst represented by an organoaluminum compound such as a trialkylaluminum or aluminoxane,
If desired, it may be added. The amount of these cocatalysts to be added is preferably within a range of 1,000 mol or less, preferably 500 mol or less as aluminum atoms in total with aluminum derived from aluminoxane per mol of transition metal in the solid fine particles.

Further, the prepolymerization of the olefin is carried out in the presence of hydrogen to control the molecular weight of the resulting olefin polymer, and the intrinsic viscosity [η] measured in decalin at 135 ° C. is 0.1 to 10 dl. / G, preferably 0.2-7 dl
/ G range.

The preactivated metallocene-supported catalyst is used as a slurry in which the prepolymerization of the olefin has been completed, or after the prepolymerization of the olefin has been completed, washed with an aliphatic hydrocarbon and resuspended in the aliphatic hydrocarbon. It is used as a main component of an olefin polymerization catalyst in a cloudy state or in a state where an aliphatic hydrocarbon is separated and dried.

In the present invention, the catalyst for olefin polymerization comprises the metallocene-supported catalyst as the main component and an organoaluminum compound as a scavenger, for example, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tributylaluminum, tributylaluminum, Hexyl aluminum, trialkyl aluminum such as trioctyl aluminum, dimethyl aluminum hydride, diethyl aluminum hydride, diisopropyl aluminum hydride, dialkyl aluminum hydride such as diisobutyl aluminum hydride, dimethyl aluminum chloride, diethyl aluminum chloride, diisopropyl aluminum chloride, diisobutyl aluminum chloride, etc. Gials Le aluminum chloride, a combination of methyl aluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum sesquichloride bromide, alkylaluminum sesquihalide such as isopropyl aluminum sesquichloride, and the like a mixture of two or more thereof.

Preferred organoaluminum compounds are trialkylaluminums such as triethylaluminum, triisobutylaluminum, tributylaluminum, trihexylaluminum and trioctylaluminum, and dialkylaluminum hydrides such as diisobutylaluminum hydride, especially triethylaluminum and tributylaluminum. Further improves the olefin polymerization activity of the metallocene supported catalyst,
Further, the effect of increasing the molecular weight of the obtained olefin polymer is remarkable, which is preferable.

The amount of the organoaluminum compound used is:
1 to 5,000 mol as Al in the organoaluminum compound per mol of the transition metal in the catalyst for olefin polymerization,
Preferably 5-3,000 mol, particularly preferably 10-
It is in the range of 1,000 moles.

In the present invention, the intended polymerization of the olefin is usually carried out under the same conditions as the polymerization conditions of the olefin using a known Ziegler-Natta catalyst.
For example, usually in the presence of hydrogen, a molecular weight regulator,
Polymerization temperature -50 to 150 ° C, preferably -10 to 100
C. and the polymerization pressure at atmospheric pressure to 7 MPa, preferably 0.2 to 5 MPa.
While maintaining a, the olefin is supplied and the olefin is polymerized for about 1 minute to 20 hours.

The amount of the olefin polymerization catalyst used was 1 × in terms of transition metal in the catalyst per 1 liter of polymerization volume.
10 ^-10 to 1 × 10 ^-3 mol, preferably 1 × 10 ^-9 to 1
× 10 ^-4 mol. By setting the amount of the olefin polymerization catalyst in the above range, it is possible to maintain an efficient and controlled polymerization reaction rate of olefin. In addition,
The term "polymerization volume" refers to the volume of the liquid phase portion in the polymerization vessel in the case of liquid phase polymerization and the volume of the gas phase portion in the polymerization vessel in the case of gas phase polymerization.

After the completion of the polymerization of the olefin, the desired olefin polymer is obtained after passing through known post-treatment steps such as a catalyst deactivation treatment step, a catalyst residue removal step and a drying step, if necessary.

The obtained target olefin polymer may be filled with an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, a lubricant, a flame retardant, an antiblocking agent, a coloring agent, an inorganic or organic material, if necessary. After blending various additives such as an agent and various synthetic resins, the mixture is usually heated, melted and kneaded, and further provided as pellets cut into granules for the production of various molded products.

[0059]

The present invention will be described in more detail with reference to Examples and Comparative Examples. Definitions of terms used in Examples and Comparative Examples and measurement methods are as follows.

(A) Preparation of Preactivated Metallocene-Supported Catalyst Example 1 A well dried, nitrogen-purged 5 L flask was charged with dimethylsilylene (2,3,5-trimethylcyclopentadienyl) ( 6.1 g (14.1 mmol) of 2 ', 4', 5'-trimethylcyclopentadienyl) zirconium dichloride
l) and 4,160 mmol of a toluene-diluted product of methylaluminoxane in terms of Al were charged, and reacted by stirring and holding for 10 minutes. The solution containing the reaction product is then
Silica (Grace Davison) fired at 0 ° C for 8 hours 1
Then, 00 g was added thereto, and the mixture was brought into contact with the mixture while stirring at 100 ° C. for 1 hour to produce a slurry containing a solid product.

The slurry containing the solid product was cooled to 0 ° C. over 10 minutes, added with 2,800 ml of n-hexane, washed while stirring for 10 minutes, and then allowed to stand to separate the supernatant liquid ( Solvent) was removed by decantation. After repeating the same washing and solvent separation operations three times, 2,800 ml of n-hexane was added to obtain a slurry in which solid fine particles were dispersed in n-hexane.

At 0 ° C., 4,500 ml / m 2 of propylene was added to the solid fine particles / n-hexane slurry obtained above.
The mixture was continuously added at a flow rate of 50 minutes for prepolymerization. After standing, the supernatant (solvent) was removed by decantation, washed with 2,800 ml of n-hexane, and the operation of separating the solvent was repeated 5 times. The obtained metallocene-supported catalyst was obtained. The composition analysis result of the obtained preactivated metallocene-supported catalyst showed that 0.22 wt% of Zr was present in the preactivated metallocene-supported catalyst.

(B) Polymerization of Propylene (Effect of Ester Compound) Various amounts of an ester compound are present in an olefin polymerization reaction system using an olefin polymerization catalyst containing a metallocene-supported catalyst prepared as a main component. The effect was evaluated by measuring the following characteristics. Olefin polymerization activity: weight of polypropylene produced per gram of preactivated metallocene-supported catalyst (unit: g / g catalyst). Melt flow rate (MFR): According to JIS K7210, conditions 14 in Table 1 (load 21.18 N, temperature 230
(° C) (unit: g / 10 min).

Example 2 N-hexane (0.8 L) was charged into a nitrogen-substituted 1.5 L stainless steel polymerization vessel equipped with a stirrer. Subsequently, 1.0 mmol of triethylaluminum and methyl paratoluate (chemical formula: H
1.76 × 10 ⁻⁶ mol of ₃ CC ₆ H ₄ C00CH ₃ , molecular weight: 150.2 g / mol (manufactured by Teijin Limited) and 100 mg of the above-prepared preactivated supported catalyst were charged. Subsequently, while the temperature in the polymerization vessel was raised to 50 ° C., propylene was supplied into the polymerization vessel so that the pressure in the polymerization vessel was maintained at 1.08 MPa, and slurry polymerization of propylene was continued for 2 hours. After normal post treatment, polypropylene 204g
I got In this polymerization reaction system, methyl paratoluate contains a polymerization medium (a total of n-hexane and propylene) 1
There were 1.1 × 10 ⁻⁶ mol per L. The molar ratio of the ester compound (methyl paratoluate) / transition metal (Zr) was 0.73. From the amount of produced polypropylene, the olefin polymerization activity was calculated to be 2,040 g / g catalyst. The MFR was 82 g / 10 min.

Example 3 Propylene was polymerized under the same conditions as in Example 2 except that the amount of methyl paratoluate added was changed to 3.52 × 10 ⁻⁶ mol to obtain 210 g of polypropylene. In this polymerization reaction system, 2.2 × 10 ⁻⁶ mol of methyl paratoluate was present per 1 L of polymerization medium (total of n-hexane and propylene). The molar ratio of the ester compound (methyl paratoluate) / transition metal (Zr) was 1.46. From the amount of the produced polypropylene, the olefin polymerization activity was calculated to be 2,100 g / g catalyst. MFR
Was 80 g / 10 min.

Example 4 Propylene was polymerized under the same conditions as in Example 2 except that the amount of methyl paratoluate added was 7.04 × 10 ⁻⁶ mol, to obtain 220 g of polypropylene. In this polymerization reaction system, 4.4 × 10 ⁻⁶ mol of methyl paratoluate was present per 1 L of polymerization medium (a total of n-hexane and propylene). The molar ratio of the ester compound (methyl paratoluate) / transition metal (Zr) was 2.92. From the amount of produced polypropylene, the olefin polymerization activity was calculated to be 2,200 g / g catalyst. MFR
Was 75 g / 10 min.

Example 5 In Example 2, the amount of methyl paratoluate added was changed to 1
Propylene was polymerized under the same conditions as in Example 2 except that the amount was changed to 4.08 × 10 ⁻⁶ mol, to obtain 215 g of polypropylene. In this polymerization reaction system, 8.8 × 10 ⁻⁶ mol of methyl paratoluate was present per liter of the polymerization medium (total of n-hexane and propylene). Ester compound (methyl paratoluate) / transition metal (Zr) molar ratio is 5.48
Met. From the amount of the produced polypropylene, the olefin polymerization activity was calculated to be 2,150 g / g catalyst. MF
R was 68 g / 10 min.

Example 6 Example 2 was repeated except that the ester compound was replaced with methyl paratoluate and ethyl paratoluate was used.
The same conditions as in Example 2, that is, the molar ratio of ester compound (ethyl paratoluate) / transition metal (Zr) = 0.7.
In 3 the propylene was polymerized to obtain 200 g of polypropylene. From the amount of the produced polypropylene, the olefin polymerization activity was calculated to be 2,000 g / g catalyst. MFR was 80 g / 10 min.

Comparative Example 1 Propylene was polymerized under the same conditions as in Example 2 except that methyl paratoluate was not added, that is, the molar ratio of the ester compound (methyl paratoluate) / transition metal (Zr) was changed to 0. Then, 170 g of polypropylene was obtained. The olefin polymerization activity was calculated to be 1,700 g / g catalyst from the amount of the produced polypropylene. MFR is 1
It was measured as 30 g / 10 min.

Comparative Example 2 Propylene was polymerized under the same conditions as in Example 2 except that the amount of methyl paratoluate added was 2.0 × 10 ⁻⁴ mol, but no polypropylene was obtained. Was. In this polymerization reaction system, 1.25 × 10 ^-4 mol of methyl paratoluate was present per liter of the polymerization medium (total of n-hexane and propylene). Ester compound (methyl paratoluate) / transition metal (Zr) molar ratio is 83
Met. Because polypropylene could not be obtained,
It is presumed that the olefin polymerization activity itself of the metallocene-supported catalyst was deactivated by the excessively added ester compound.

[0071]

According to each of the above Examples, when compared with the polymerization reaction system of Comparative Example 1 in which no ester compound is present, a very small amount of the ester compound present in the polymerization reaction system was used for the preactivated metallocene-supported catalyst. It has an effect of significantly improving olefin polymerization activity. Also,
The MFR of the propylene polymer obtained in each example was smaller than the MFR of the propylene polymer obtained in Comparative Example 1 in each case, indicating that a higher molecular weight propylene polymer was produced. In the present invention, the olefin polymerization activity of the metallocene-supported catalyst that tends to decrease is maintained at a high level,
An object of the present invention is to provide a method for producing an olefin polymer, which makes it possible to obtain a higher molecular weight olefin polymer,
Its industrial significance is extremely large.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a manufacturing process of the present invention.

Continuing on the front page F term (reference) 4J028 AA01A AB00A AB01A AC01A AC08A AC09A AC10A AC18A AC19A AC20A AC26A AC27A AC28A AC29A AC31A AC37A AC38A AC39A AC42A AC49A BA01A BA01B BB01A BB01B27 BC16ABC19BBC BC BC CA28B CA29A CA29B CB09A CB09B CB43C DA01 DA02 DA03 DA08 DA09 DB03A DB03B DB04A DB04B DB04C EA01 EB02 EB04 EB05 EB07 EB08 EB09 EB10 EB13 EB14 EB16 EB17 EB18 EB21 FA04 EC03 FA01 EC04

Claims (4)

[Claims] 1. A polymerization reaction system for polymerizing an olefin using an olefin polymerization catalyst containing a metallocene-supported catalyst as a main component has the following general formula (1): ^Ra- COO- ^Rb (1) Wherein ^Ra and ^Rb each independently represent a carbon number of 1 to
At least one ester compound represented by an aliphatic hydrocarbon group of 20 or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may be substituted with the aliphatic hydrocarbon group), A method for producing an olefin polymer, wherein the molar ratio of transition metal in the catalyst is in the range of 0.001 to 50. 2. The amount of the ester compound present in the polymerization reaction system is 1 × 10 ^-8 to 1 × 10 ^-4 mo per liter of the polymerization medium.
2. The method of claim 1, wherein the range is l. 3. The method according to claim 1, wherein the ester compound is methyl paratoluate or ethyl paratoluate. 4. The method according to claim 1, wherein the olefin polymer is a propylene polymer.