JP2017137464A - Olefin polymerization method by refined olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain a polymer at high productivity in the polymerization of olefin, when carbon dioxide as impurities is removed from an olefin raw material, using a removal refining method for carbon dioxide in the olefin raw material, performable economically, easily and efficiently, and capable of feeding sufficiently refined monomer raw material to olefin polymerization.SOLUTION: Raw material olefin containing carbon dioxide as impurities is contacted with a hybrid based adsorbent made of a mixture of active alumina and zeolite, the raw material olefin is refined, and thereafter, the refined olefin is contacted with a transition metal complex catalyst, and polymerization is performed.SELECTED DRAWING: None

Description

  The present invention relates to a method for polymerizing olefins using purified olefins, and more specifically, in the polymerization of olefins using a transition metal complex catalyst, when the raw material olefin contains carbon dioxide as an impurity, the olefin purified using a hybrid adsorbent is disclosed. Is used to sufficiently reduce the catalytic activity and to obtain a polymer in a high yield.

In general, when homopolymerization of olefins or copolymerization between olefins using a Ziegler-Natta catalyst, a (co) polymer having a wide molecular weight distribution and composition distribution is obtained. In the case of homopolymerization of olefins, a polymer having a wide molecular weight distribution including many low molecular weight components is obtained. In the case of copolymerization between olefins, in addition to the wide molecular weight distribution, a wide composition including many low crystalline components. A copolymer of distribution is obtained.
In such specificity, these components cause problems in physical properties and molding processing, and when the amount of the low molecular weight component or the low crystalline component increases, odor, deterioration of appearance, touch feeling (stickiness, etc.), etc. Problems arise and adversely affect quality.
Furthermore, unlike the metallocene catalyst described later, the Ziegler-Natta catalyst has a low reactivity with hydrogen, which is a chain transfer agent, so a large amount of hydrogen must be supplied in order to produce a (co) polymer having a low molecular weight. And the polymerization activity is also reduced.

  In recent years, metallocene catalysts with few of these drawbacks have been developed. Metallocene catalysts have good reactivity with hydrogen, which is a chain transfer agent, and have a low molecular weight even when hydrogen is not supplied to reduce polymerization activity (co-polymerization). ) It is possible to polymerize the polymer. In addition, the metallocene catalyst is known to give a good olefin (co) polymer with a narrow molecular weight distribution and composition distribution and less sticky components because the active site is homogeneous compared to the Ziegler-Natta catalyst. Further, it also has a feature of producing a propylene polymer having a high stereoregularity.

  On the other hand, metallocene catalysts are extremely sensitive to impurities in the raw material olefin, and the polymerization activity and polymer quality are greatly influenced by the purity of the raw material olefin. It was difficult to industrially produce an olefin (co) polymer by using it.

In recent years, demand for ethylene and propylene has rapidly increased as a basic raw material for the petrochemical industry, especially as a monomer for the production of polyethylene and polypropylene. Industrial ethylene and propylene have been secured by (Fluid Catalytic Cracking Process) and the like.
Industrial ethylene and propylene are obtained using naphtha, crude oil, natural gas, etc., but in high temperature reaction processes such as cracking, for example, a small amount of carbon monoxide and water are added by side reaction with water added as a diluent. Carbon dioxide is generated as a by-product. Generally, ethylene and propylene immediately after production contain a small amount of carbon monoxide, carbon dioxide, and other impurities. Next, in order to separate a fraction such as ethylene, carbon monoxide can be sufficiently removed together with methane and the like in a purification step using a separation apparatus such as a distillation column.
However, it is difficult to remove carbon dioxide sufficiently, and ethylene and propylene contain carbon dioxide of about several ppm (volume) to several hundred ppm (volume). Impurities in the raw material ethylene and propylene are often catalyst poisons for olefin polymerization catalysts, and various purifications have been performed.

  Further, as an effective method for selectively producing propylene for industrial propylene in recent years, a method for producing propylene by reacting methanol and / or dimethyl ether, a so-called MTO process (a process for producing olefin from methanol) has been attracting attention. I'm bathing. On the other hand, as a method for producing methanol, a method of producing methanol using a hydrocarbon derived from natural gas is the mainstream, but instead of natural gas, a gas derived from coal such as coal gas, coal coke oven gas, etc. There is a method of producing methanol using Propylene obtained using coal-derived gas may contain trace amounts of impurities such as carbon dioxide in the synthesis gas produced from coal-derived gas. In this case, there are concerns about various problems in the polymerization of olefins, and the necessity and demand for reducing impurities as much as possible are increasing.

  Under such circumstances, impurities such as carbon dioxide in the olefin raw material for industrial use, which have an adverse effect as a catalyst poison in the polymerization of olefin metallocene catalysts represented by ethylene and propylene, are efficiently and economically removed as much as possible. The need is very high.

  Conventionally, low molecular weight impurities such as carbon monoxide in olefins are separated and removed in a light boiling removal tower in the raw material purification step, but carbon dioxide has a molecular weight close to that of propylene and is a light boiling removal tower. Therefore, it was necessary to remove using a purification catalyst (adsorbent).

In general, the method of selectively removing a trace amount of harmful components contained as impurities in a mixed gas can be broadly divided into a method of removing by chemical reaction (referred to as “chemical removal method”) and a method of physical adsorption. It is divided into the method (referred to as “physical removal method”).
Specifically, as a method for removing carbon dioxide as an impurity in industrial olefins, the following removal methods have been proposed.

Active alumina is known as the most common purification catalyst (adsorbent) for removing carbon dioxide (see Patent Document 1), and is currently being applied to olefin purification.
In addition, studies are being made on improving the performance of activated alumina. For example, an adsorbent comprising activated alumina carrying an alkali metal oxide, hydroxide, nitrate, acetate, etc. is being developed (patent) Reference 2).
However, since adsorption by activated alumina is a chemical removal method that mainly involves chemical reaction, the active sites in the adsorbent change in a relatively short period of time with use, and the performance does not recover even after regeneration. The short life was a difficult point.

  In addition, as a method for removing carbon dioxide by a physical removal method, for example, a removal method using a catalyst (for example, containing zeolite, alumina, and a metal precursor) containing zeolite (molecular sieve) as a main component can be cited ( However, the removal efficiency was not always sufficient.

  Therefore, although removal of impurities such as carbon dioxide in olefins by these known purification catalysts shows a certain effect, there is still much room for improvement in the adsorption performance.

JP-A 63-240915 US Pat. No. 4,493,715 JP 2002-253959 A Special table 2010-505033 gazette

Conventionally, industrial olefin raw materials produced by various methods usually contain carbon dioxide, acetylene, sulfur impurities, and the like. In order to use this industrial olefin as a raw material monomer for polymer production, the carbon dioxide contained in the industrial olefin raw material, which has an adverse effect as a catalyst poison, is a concentration level lower than 5 volppm, sometimes It is necessary to remove to a level below 1 volppm to prevent poisoning of transition metal complex catalysts represented by metallocene catalysts.
As described above in the background art, the conventional carbon dioxide removal method uses activated alumina or zeolite (molecular sieve) as a purification catalyst. However, the transition metal complex catalyst is easily affected by impurities such as carbon dioxide. On the other hand, it could not be said that sufficient purification was achieved.

  Therefore, the present invention is economical, simple and efficient in removing carbon dioxide from industrial olefin raw materials, and can supply a monomer raw material sufficiently purified for olefin polymerization, which is high in the polymerization of such olefins. It is an object of the present invention to develop an olefin polymerization method capable of stably obtaining a polymer with productivity.

  In order to solve the above-described problems of the present invention, the present inventors have tried and considered a method for removing and purifying carbon dioxide from an olefin raw material using various purification catalysts (adsorbents), and are economical, simple and efficient. As a result of seeking a carbon dioxide removal purification method that can supply a monomer raw material sufficiently purified for olefin polymerization, it has been found that the problem of the present invention can be solved by employing a specific adsorbent. The present inventors have created an olefin polymerization method of the present invention that utilizes a transition metal complex catalyst, particularly a metallocene catalyst.

  In the present invention, as a main feature of the invention, by using a hybrid adsorbent composed of a mixture of activated alumina and zeolite (hereinafter also simply referred to as “hybrid adsorbent”), an olefin raw material, particularly propylene and ethylene, is used. In addition, carbon dioxide as an impurity that causes catalyst poisoning, acetylene compounds, and the like are more efficiently and reliably removed than before, and a technique for greatly suppressing the decrease in catalyst activity is used for olefin polymerization. Is.

  Therefore, according to the first invention of the present invention (basic invention; claim 1), the raw material olefin containing carbon dioxide as an impurity is brought into contact with a hybrid adsorbent composed of a mixture of activated alumina and zeolite to purify the raw material olefin. After that, the olefin polymerization method is characterized in that the purified olefin is polymerized by contacting with the transition metal complex catalyst.

  As an incidental invention or an embodiment of the invention (each invention of the dependent claims) accompanying the basic invention of the present invention, as a second invention, the raw material olefin further contains an acetylene compound of 5 volppm or less as an impurity. A method for polymerizing olefins according to the first invention, characterized in that, as a third invention, the method for polymerizing olefins according to the first or second invention, wherein the transition metal complex catalyst is a metallocene catalyst. A fourth invention is the olefin polymerization method according to the third invention, wherein the metallocene catalyst is supported on an ion-exchangeable layered silicate.

  The fifth invention is the olefin polymerization method according to the first to fourth inventions, characterized in that the hybrid adsorbent is pre-treated at a temperature of 100 to 650 ° C in advance. A method for polymerizing olefins according to the first to fifth inventions, characterized in that the pore diameter of alumina is 1 to 100 nm and the average pore diameter of zeolite is 0.2 to 1 nm. The method for polymerizing olefins according to the first to sixth inventions, wherein the contact temperature between the raw material olefin containing carbon dioxide as an impurity and the hybrid adsorbent is 0 to 100 ° C.

Further, as an eighth invention, the raw material olefin contains 100 volppm or less with carbon dioxide as an impurity, the olefin polymerization method according to the first to seventh inventions, and as the ninth invention, carbon dioxide Before and after contacting the raw material olefin containing impurities as a hybrid adsorbent with at least one of the following (1) to (3), the method for olefin polymerization in the first to eighth inventions: It is.
(1) Zeolite (2) Metal oxide or composite oxide of metal oxide (3) Activated alumina

  Still further, as a tenth invention, there is provided an olefin polymerization method according to the first to ninth inventions characterized in that the raw material olefin is ethylene and / or propylene. The olefin polymerization method according to the tenth invention is provided, wherein the coalescence is an ethylene / propylene copolymer having an ethylene content of 6 wt% or less.

  In the present invention, when removing carbon dioxide as an impurity from an olefin raw material, a conventional purification catalyst is not used, and the removal can be performed economically, simply and efficiently, and a sufficiently purified raw material olefin can be supplied. Therefore, in the olefin polymerization using a transition metal complex catalyst such as a metallocene catalyst, it is possible to sufficiently suppress a decrease in catalytic activity due to impurities, and it is possible to stably produce a polymer with high productivity. .

The basic constitution of the present invention is that a raw material olefin containing carbon dioxide as an impurity is brought into contact with a hybrid adsorbent composed of a mixture of activated alumina and zeolite, and then brought into contact with a transition metal complex catalyst such as a metallocene catalyst. An olefin polymerization method characterized by polymerization.
In the following, the olefin polymerization method of the present invention according to each claim of the present invention will be described in detail.

[I] Raw Olefin As the olefin used as a raw material in the present invention, an industrial olefin containing carbon dioxide produced by various methods can be used. The present invention is suitably applied when industrial ethylene obtained from catalytic cracking products and produced by separation of C2,3 fractions, and FCC propylene (FCC; Fluid Catalytic Cracking Process) are used.
The industrial olefin raw material may further contain 5 volppm or less of an acetylene compound as an impurity.

Carbon dioxide contained in these raw material olefins is preferably applied in the case of 100 vol ppm or less, and more preferably 10 vol ppm or less. If carbon dioxide is contained in the raw material olefin at a concentration exceeding 100 volppm, the concentration is too high and the treatment capacity by the adsorbent becomes inefficient, so distillation, PSA (Pressure Swing Adsorption) method, etc. It is desirable to reduce the concentration of carbon dioxide to 100 volppm or less in advance by other means.
Even if an industrial olefin raw material containing a high concentration of carbon dioxide as an impurity is accepted in a polyolefin production plant, the treatment with the hybrid adsorbent of the present invention causes a significant decrease in catalytic activity in the polymerization with a transition metal complex catalyst. It is possible to produce a high-quality polymer with a high yield.

[II] Hybrid Adsorbent (1) Composition of Adsorbent The hybrid adsorbent used in the present invention is a mixture of activated alumina and zeolite, and is usually activated alumina 20 in a total of 100% by weight of activated alumina and zeolite. -80 wt% and zeolite 80-20 wt%, preferably a mixture of activated alumina 30-70 wt% and zeolite 70-30 wt%.
In the present invention, in the purification of the olefin raw material, the hybrid adsorbent has a feature capable of removing not only the impurity carbon dioxide but also the acetylene impurity.
Such a hybrid adsorbent is a conventionally known adsorbent, and a commercially available hybrid adsorbent may be used. As a commercial item, for example, AZ-300 manufactured by UOP / Union Showa is known.

  The activated alumina that constitutes the hybrid adsorbent is the one obtained by transferring alumina hydroxide to porous aluminum oxide with low crystallinity to give adsorption ability, and has a high specific surface area and high pore volume and is excellent. Has adsorption capacity. The activated alumina may be a commercially available product, or may be produced by a known method.

The pore diameter of the activated alumina is usually 1 to 100 nm, preferably 1 to 80 nm. The average particle diameter of the activated alumina is not particularly limited, and it is preferable that the average pore diameter is in the above range because highly polar impurities such as water and alcohol can be adsorbed efficiently.
Although it does not restrict | limit especially as a preferable activated alumina, (gamma) -alumina etc. are mentioned.

As the zeolite constituting the hybrid adsorbent, a commercially available product may be used, or it can be produced by a known method.
The average pore diameter of the zeolite is usually 0.2 to 1 nm, preferably 0.5 to 1 nm. The average particle diameter of the zeolite is not particularly limited, and it is preferable that the average pore diameter is in the above range because various impurities including carbon dioxide can be adsorbed efficiently.

Although it does not restrict | limit especially as a preferable zeolite, Zeolite X, Y, A, etc. are mentioned, Especially preferably, zeolite X is mentioned. (In addition, these various zeolites are common names as types of zeolite and are well known.)
If the olefin contains a lot of polar impurities such as water and alcohol, these impurities are adsorbed on the hybrid adsorbent in preference to carbon dioxide, so zeolite (molecular sieve) etc. It is preferable to use the adsorbent in front of the hybrid adsorbent.
The average particle size of the single zeolite used in combination with the hybrid adsorbent is not particularly limited, but it is preferable to use an average pore size of 0.5 to 1 nm.

(2) Shape of adsorbent The shape of the hybrid adsorbent used in the present invention is not particularly limited, and may be a pellet, powder, granule, a droplet, a disk, or the like. The shape of the adsorbent may be appropriately selected according to the usage mode, and the size thereof can also be appropriately selected according to the usage conditions.

[III] Treatment conditions (1) Pretreatment of hybrid adsorbent (activation treatment)
The hybrid adsorbent of the present invention is preferably heat activated as a pretreatment.
The pretreatment (activation treatment) of the hybrid adsorbent in the present invention is a heat treatment, and the temperature thereof is 100 to 650 ° C., preferably 200 to 600 ° C., more preferably 300 to 600, under an inert gas flow. ° C, most preferably 400-600 ° C. When the pretreatment temperature is within this range, the zeolite crystals are not severely collapsed, and the removal efficiency is appropriate. As the inert gas, nitrogen, argon, helium or the like can be used, and use of nitrogen is economical and preferable.
The pretreatment (activation treatment) time of the present invention is 0.1 to 100 hours, preferably 0.5 to 50 hours, more preferably 1 to 25 hours.

(2) Multistage treatment In the present invention, when the olefin raw material is subjected to an adsorption treatment with a hybrid adsorbent, it is also preferable to perform a plurality of adsorption treatments, that is, a multistage treatment.

(3) Contact temperature of olefin and hybrid adsorbent The contact temperature of the present invention is preferably 0 to 100 ° C, more preferably 10 to 60 ° C, and further preferably 20 to 50 ° C. When the treatment (contact) temperature is within this range, in the case of liquefied olefin, the treatment operation is efficient without vaporization. In the case of gaseous olefins, there is no concern that side reactions will occur. If the treatment temperature is too low, the removal efficiency is lowered.

(4) Contact time of olefin and hybrid adsorbent The contact time of the present invention is appropriately selected according to the carbon dioxide concentration in the olefin, the amount of the hybrid adsorbent, the contact temperature, the contact pressure, and the like. Usually, it is 1 minute to 100 hours, preferably 5 minutes to 80 hours.

(5) Contact pressure of olefin and hybrid type adsorbent The contact pressure of the present invention can be carried out at normal pressure, but it is also carried out under a pressure of 0.2 to 5 MPa, preferably 0.5 to 4 MPa. Can do.

(6) Contact method of olefin and hybrid adsorbent The contact method of the present invention is usually contacted in a gaseous state with olefin being in circulation, but is not limited to this, and in the case of propylene, it is contacted in liquid form. May be.
The filling mode of the hybrid adsorbent may be appropriately selected according to the shape of the contact tower, and a fixed bed is generally used, but it can also be packed as a moving bed, a fluidized bed or the like.

(7) Supplementary treatment with other adsorbents Normally, industrial olefin raw materials contain impurities other than carbon dioxide (for example, H ₂ O, CO, COS, acetylenic compounds, etc.), so that they are used for hybrid adsorbent treatment. It is preferable to perform a preliminary treatment and a post-treatment in advance. Additional purification catalysts that can be used in combination with hybrid adsorbents include synthetic zeolites (eg, molecular sieves (MS) 3A, 4A, 5A, 13X) and activated alumina, or copper oxide, zinc oxide, palladium oxide, nickel oxide. And metal oxides such as
For example, before and after the adsorption column packed with the hybrid adsorbent, (b) an adsorption column packed with (i) zeolite (molecular sieve), (b) metal oxide, or (c) activated alumina is used in combination. Impurities can be removed.

  That is, in the polymerization of olefins by a catalyst that is easily affected by impurities such as metallocene catalysts, in order to reduce the carbon dioxide concentration, the olefins are contact-treated with a hybrid adsorbent comprising a mixture of activated alumina and zeolite of the present invention. Is very useful, but it can be said to be contact with raw material olefin and various conventional refinable purification catalyst parts, which can be said to be combined contact with the above (a) to (c), except for carbon dioxide. This makes it possible to remove various other impurities. One or more of these combined contacts may be combined arbitrarily.

An example of such an embodiment using so-called combined contact is as follows.
(1) Combined contact with hybrid adsorbent after contact with synthetic zeolite such as molecular sieve (2) Combined contact with hybrid adsorbent after metal oxide contact (3) Metal oxide after contact with hybrid adsorbent (4) Hybrid adsorbent contact after metal oxide or metal oxide complex oxide contact, then multistage combination with metal oxide or metal oxide complex oxide Contact (5) Combined contact with hybrid adsorbent after contact with activated alumina

  The above-mentioned contact treatment with the hybrid adsorbent and the purification catalyst that can be added can be changed in various combinations in consideration of the properties and quality of the olefin, and the number of times can be arbitrarily set in multiple stages. This is because contact with a hybrid adsorbent composed of a mixture of activated alumina and zeolite exclusively reduces the carbon dioxide content, whereas this additional purifying catalyst can be another catalyst poison. It is also beneficial to gradually reduce the content of impurities.

Specifically, for example, when ethylene or propylene is used for polymerization, it is remarkably useful in that the activity of the transition metal complex catalyst is maintained as a whole by detoxifying any catalyst poison.
In this way, olefins typified by ethylene and propylene are preliminarily contacted with various types of refining catalyst parts that can be added such as molecular sieve contact, metal oxide or metal oxide composite oxide contact, and then adsorbed in a hybrid system. Combined contact with the agent is also beneficial. The hybrid adsorbent treatment can be performed in two or three stages, and an optional purification catalyst portion can be provided in multiple stages, and any mode in which the contact before and after the contact is arbitrarily changed can be applied to the technology of the present invention. Included in the range.

(8) Others When carbon dioxide remains in the raw material olefin, when triisobutylaluminum is supplied as an optional component into the polymerization system, it reacts with triisobutylaluminum to generate isovaleric acid as a by-product, resulting in a polymer. It may cause a product odor. In the present invention, since carbon dioxide is sufficiently removed, such a bad odor is not generated and a high-quality polymer product can be supplied. The presence or absence of carbon dioxide impurities in the olefin raw material can be verified by a sensory test for off-flavors based on the sense of smell of the product polymer.
In addition, establishment of a purification technology for olefin raw materials in polymerization using a transition metal complex catalyst can guarantee stable production of a polyolefin production plant.

[IV] Concentration measurement of carbon dioxide This is performed by GC / MS analysis (gas chromatography / mass analysis) generally used for gas concentration measurement.

[V] Metallocene Catalyst In the present invention, the transition metal complex catalyst includes a coordination catalyst of a late transition metal complex, but examples of metallocene catalysts that are representative examples of transition metal complex catalysts are generally conjugated five-membered. Examples include a catalyst containing a metallocene complex (W) composed of a transition metal compound of Groups 4 to 6 of the periodic table having a ring ligand and a promoter (X).

(1) Metallocene complex As a metallocene complex (W), the metallocene complex of the transition metal compound of the periodic table 4-6 group which has a conjugated 5-membered ring ligand is mentioned as a typical thing, Among these, A bridged metallocene complex represented by the general formula (1) is preferable.

  In formula (1), M is a metal atom of a transition metal selected from Groups 4 to 6 of the periodic table. F and G are auxiliary ligands that react with the cocatalyst (X) to produce an active metallocene having olefin polymerization ability. E and E ′ are an optionally substituted cyclopentadienyl group, indenyl group, fluorenyl group, or azulenyl group. Q is a group that crosslinks E and E ′. E and E ′ may further have a substituent on the side ring.

As E and E ′, an indenyl group or an azulenyl group is preferable, and an azulenyl group is particularly preferable.
Q represents a binding group that crosslinks between ligands such as two conjugated five-membered rings at an arbitrary position, and is preferably an alkylene group, a silylene group, or a germylene group.
M is a metal atom of a transition metal selected from Groups 4 to 6 of the periodic table, preferably titanium, zirconium, hafnium or the like. Zirconium or hafnium is preferred.
F and G are auxiliary ligands that react with the cocatalyst (X) to produce an active metallocene with olefin polymerization ability, so that F and G are coordinated as long as this purpose is achieved. The type of the child is not limited, and examples thereof include a hydrogen atom, a halogen atom, a hydrocarbon group, a hydrocarbon group having a hetero atom. Among these, preferred are a hydrocarbon group having 1 to 10 carbon atoms and a halogen atom.

Here, as a typical metallocene complex, in a metallocene complex having a structure in which two cyclopentadienyl ligands are present and they are bridged, the cyclopentadienyl ring is further condensed. As an azulene type,
Dimethylsilylenebis {1- (2-methyl-4-isopropyl-4H-azurenyl)} hafnium dichloride,
Dimethylsilylenebis {1- (2-methyl-4-phenyl-4H-azurenyl)} hafnium dichloride,
Dimethylsilylenebis [1- {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] hafnium dichloride,
Dimethylsilylenebis [1- {2-methyl-4- (4-fluorophenyl) -4H-azurenyl}] hafnium dichloride,
Dimethylsilylene bis [1- {2-methyl-4- (3-chlorophenyl) -4H-azurenyl}] hafnium dichloride, which is an azulene-based, and other conjugated multi-membered ring ligands are different from indenyl and the like. As a thing,
Dimethylsilylene [1- {2-methyl-4- (4-biphenylyl) -4H-azurenyl}] [1- {2-methyl-4- (4-biphenylyl) indenyl}] hafnium dichloride,
Dimethylsilylene {1- (2-ethyl-4-phenyl-4H-azulenyl)} {1- (2-methyl-4,5-benzoindenyl)} hafnium dichloride and the like, including two indenyl ligands As a metallocene complex having a structure in which they are crosslinked,
Dimethylsilylenebis {1- (2-methyl-4-phenylindenyl)} hafnium dichloride,
Dimethylsilylenebis {1- (2-methyl-4,5-benzoindenyl)} hafnium dichloride,
And dimethylsilylenebis [1- {2-methyl-4- (1-naphthyl) indenyl}] hafnium dichloride.

(2) Cocatalyst The cocatalyst (X) is a component that activates the metallocene complex (W), and can react with an auxiliary ligand of the metallocene complex to convert the complex into an active species having olefin polymerization ability. Specific examples of the compound include the following (X-1) to (X-4).
(X-1) Aluminum Oxy Compound (X-2) Ionic Compound or Lewis Acid (X-3) Solid Acid that can React with Metallocene Complex (W) to Convert Metallocene Complex (W) to Cation (X-4) Ion exchange layered silicate

The cocatalyst (X) has an acid site with a pKa of -8.2 or less, and its amount neutralizes the cocatalyst (X) in order to neutralize it, and more than 0.001 mmol of 2,6-dimethylpyridine. It is preferable that it is required, and more preferably 0.01 mmol or more.
The amount of acid sites having a pKa of -8.2 or less is measured by the method described in JP-A-2002-53609.
Here, acid is one of the categories of substances, and is defined to refer to substances that are Bronsted acids or Lewis acids. Further, the acid point is defined as a structural unit in which the substance exhibits the properties as an acid, and the amount is determined by the amount of 2,6-dimethylpyridine required for neutralization per unit weight by an analytical means such as a titration method. Is grasped by the molar amount. An acid point having a pKa of −8.2 or less is referred to as a “strong acid point”.
The co-catalyst (X) used in the present invention has a marked improvement in polymerization activity by containing a strong acid point in a specific amount or more.

  It is well-known that the aluminum oxy compound of (X-1) can activate a metallocene complex, and as such a compound, specifically, compounds represented by the following general formulas (2) to (4) are included. Can be mentioned.

In each of the general formulas (2) to (4), R ¹ represents a hydrogen atom or a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, particularly a hydrocarbon group having 1 to 6 carbon atoms. Moreover, several R < ¹ > may be same or different, respectively. P represents an integer of 0 to 40, preferably 2 to 30.
Among the above general formulas, the compounds represented by (2) and (3) are also called aluminoxanes, and among these, methylaluminoxane or methylisobutylaluminoxane is preferable. The above aluminoxanes can be used in combination within a group and between groups. And said aluminoxane can be prepared on well-known various conditions.
The compound represented by the general formula (4) is 10 kinds of one type of trialkylaluminum or two or more types of trialkylaluminum and an alkylboronic acid represented by the general formula: R ² B (OH) ₂ : It can be obtained by a reaction of 1: 1 to 1: 1 (molar ratio). In the general formula, R ¹ and R ² represent a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms.

The compound (X-2) is an ionic compound or a Lewis acid capable of reacting with the metallocene complex (W) to convert the metallocene complex (W) into a cation, and as such an ionic compound, And a complex of a cation such as carbonium cation or ammonium cation with an organic boron compound such as triphenylboron, tris (3,5-difluorophenyl) boron or tris (pentafluorophenyl) boron.
Examples of the Lewis acid as described above include various organic boron compounds such as tris (pentafluorophenyl) boron. Furthermore, metal halides such as aluminum chloride and magnesium chloride are exemplified.
In addition, a certain thing of said Lewis acid can also be grasped | ascertained as an ionic compound which can react with a metallocene complex (W) and can convert a metallocene complex (W) into a cation.

  Examples of the solid acid (X-3) include alumina, silica-alumina, silica-magnesia, molybdic acid, niobic acid, titanic acid, tungstic acid, complex acids thereof, and heteropolyacid.

The ion-exchange layered compound (X-4) occupies most of the clay mineral, and is preferably an ion-exchange layered silicate.
An ion-exchange layered silicate (hereinafter, sometimes simply abbreviated as “silicate”) has a crystal structure in which planes formed by ionic bonds and the like are stacked in parallel with each other and have a binding force. Refers to a silicate compound in which the ions to be exchanged are exchangeable. Most silicates are naturally produced mainly as a main component of clay minerals, and therefore often contain impurities (quartz, cristobalite, etc.) other than ion-exchangeable layered silicates. You may go out.

Various known silicates can be used. Specific examples include the following layered silicates described in Haruo Shiramizu “Clay Mineralogy” Asakura Shoten (1995). Smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, etc .; vermiculites such as vermiculite; Pyrophyllite-talc group; chlorite group such as Mg chlorite; sepiolite, palygorskite and the like.
The layered silicate which formed said mixed layer may be sufficient as a silicate. The main component silicate is preferably a silicate having a 2: 1 type structure, more preferably a smectite group, and particularly preferably montmorillonite.

As for silicates, those obtained as natural products or industrial raw materials can be used as they are without any particular treatment, but it is preferable to carry out chemical treatment. Specifically, acid treatment, alkali treatment, salt treatment, organic matter treatment and the like can be mentioned. Acid treatment is preferable. These processes may be used in combination with each other. These processing conditions are not particularly limited, and known conditions can be used.
In addition, since these ion-exchange layered silicates usually contain adsorbed water and interlayer water, it is preferable to use them after removing moisture by heat dehydration under an inert gas flow. Depending on the degree of these chemical treatments, the ion exchange properties may be small, but there is no particular problem if the raw material before the chemical treatment is an ion exchangeable layered silicate.

(3) Carrier The metallocene catalyst can be used by being supported on a carrier. Examples of the carrier used in the metallocene catalyst include various known inorganic or organic fine particle solids.
Examples of inorganic solids include porous oxides, and 100 to 1,000 as necessary.
Baked at a temperature of 150 ° C, preferably 150 to 700 ° C.
Specifically, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ , or a mixture thereof, for example, SiO ₂ —MgO, SiO ₂ — Examples include Al ₂ O ₃ , SiO ₂ —TiO ₂ , SiO ₂ —V ₂ O ₅ , SiO ₂ —Cr ₂ O ₃ , SiO ₂ —TiO ₂ —MgO. Of these, those containing SiO ₂ or Al ₂ O ₃ as the main component are preferred.

Moreover, if the said promoter (X) is a solid thing, it can be used as a support | carrier and promoter, and it is preferable. Specific examples of the support / co-catalyst include (X-3) solid acid and (X-4) ion-exchange layered silicate. In order to improve the particle properties of the copolymer, various known granulations are preferably performed.
Organic fine particle solids include (co) polymers, vinyls, which are mainly composed of α-olefins having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene and 4-methyl-1-pentene. Examples thereof include solids such as (co) polymers mainly composed of cyclohexane and styrene.

The average particle diameter of the carrier is usually 5 to 300 μm, preferably 10 to 200 μm, more preferably 30 to 100 μm. The specific surface area of the support is usually 50~1,000m ² / g, preferably from 100 to 500 m ² / g. The pore volume of the carrier is usually 0.1 to 2.5 cm ³ / g, preferably 0.2 to 0.5 cm ³ / g.
Further, the cocatalyst (X) used as the carrier and cocatalyst is preferably one having an average particle diameter and a specific surface area in the same range as above.

(4) Contact of catalyst component In the contact of the metallocene complex (W), the cocatalyst (X) and the carrier, the order of contact is not limited, but there are, for example, the following methods.
(I) After contacting the metallocene complex (W) and the promoter (X), the support is brought into contact.
(Ii) After contacting the metallocene complex (W) and the carrier, the cocatalyst (X) is contacted.
(Iii) After contacting the support and the promoter (X), the metallocene complex (W) is contacted (in the case where a solid promoter such as an ion-exchange layered silicate is used as the support and promoter, And the cocatalyst (X) are originally contact-supported, and this is the order of contact).
(Iv) The metallocene complex (W), the cocatalyst (X) and the support are brought into contact at the same time.
Among these, the order of (iii) is preferable.

(5) Other components Moreover, an organoaluminum compound can be used as needed. Also in the case of using an organoaluminum compound, the organoaluminum compound may be brought into contact in any of the above steps. The method is preferably a method in which the support and the cocatalyst (X) are contacted, the organoaluminum compound is contacted, and then the metallocene complex (W) is contacted.

The temperature at which the metallocene complex (W) and the organoaluminum compound are brought into contact (in which case the cocatalyst (X) may be present) is preferably 0 to 100 ° C., more preferably 20 to 80 ° C., and particularly preferably 30-60 ° C. Within this temperature range, the reaction is not slowed and the decomposition reaction of the metallocene complex (W) does not proceed.
When the metallocene complex (W) and the organoaluminum compound are brought into contact (in this case, the cocatalyst (X) may be present), it is preferable that an organic solvent is present as a solvent. In this case, the concentration of the metallocene complex (W) in the organic solvent is preferably high, and is preferably 3 mM or more, more preferably 4 mM or more, and particularly preferably 6 mM or more.

(6) Component amount The usage-amount of a metallocene complex (W) and a co-catalyst (X) among said catalyst components is used by optimal quantity ratio in each combination.
When the promoter (X) is an aluminum oxy compound, the molar ratio of Al / transition metal is usually 10 to 100,000, preferably 100 to 20,000, and more preferably 100 to 10
, 000. On the other hand, when an ionic compound or Lewis acid is used as the promoter (X), the molar ratio of the transition metal to the transition metal is 0.1 to 1,000, preferably 1 to 100, more preferably 2 to 10. .

(7) Prepolymerization The transition metal complex catalyst is preferably used after prepolymerization, in which a small amount of the polymer is brought into contact with an olefin in advance to improve the particle properties of the (co) polymer. The olefin used for the prepolymerization is not particularly limited, but ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, Styrene or the like can be used, and it is particularly preferable to use propylene.
As a method for supplying olefin at the time of prepolymerization, any method can be used such as a supply method for maintaining the olefin at a constant speed or in a constant pressure state, a combination thereof, or a stepwise change.

The prepolymerization time is not particularly limited, but is preferably 5 minutes to 24 hours. The prepolymerization amount is preferably 0.01 to 100 parts by weight, more preferably 0.1 to 50 parts by weight with respect to 1 part by weight of the prepolymerized polymer. After completion of the prepolymerization, the catalyst can be used as it is, depending on the usage form of the catalyst, but may be dried if necessary.
The prepolymerization temperature is not particularly limited, but is usually 0 to 100 ° C, preferably 10 to 70 ° C
More preferably, it is 20-60 degreeC. Within this range, there is no possibility that the reaction rate decreases or the adverse effect that the activation reaction does not proceed, the prepolymerized polymer dissolves, the prepolymerization rate is too high, and the particle properties deteriorate, There is also no possibility that the active site is deactivated due to a side reaction.
During the prepolymerization, the prepolymerization can be carried out in a liquid such as an organic solvent, and it is preferable to do so. The concentration of the solid catalyst during the prepolymerization is not particularly limited, but is preferably 50 g / L or more, more preferably 60 g / L or more, and particularly preferably 70 g / L or more. The higher the concentration, the more active the catalyst and the higher the active catalyst.
Further, a polymer such as polyethylene, polypropylene or polystyrene, or an inorganic oxide solid such as silica or titania can be allowed to coexist during or after the contact of the above components.

[VI] Polymerization of Olefin For the polymerization of the olefin of the present invention, any type of method can be adopted as long as the transition metal complex catalyst and the monomer come into efficient contact. As a specific polymerization form, it is applied to slurry polymerization using a hydrocarbon solvent, bulk polymerization in a liquefied monomer, or gas phase polymerization substantially using no solvent.
In the case of slurry polymerization, a hydrocarbon solvent such as hexane, heptane, pentane, or cyclohexane is used as the polymerization solvent.
The polymerization reaction is applied to continuous polymerization, semi-continuous polymerization, and batch polymerization. Furthermore, a multistage polymerization method in which the polymerization reaction is performed in two or more stages having different reaction conditions is also possible.

In the present invention, triisobutylaluminum may be present when the purified olefin is contacted with the transition metal complex catalyst.
The amount of triisobutylaluminum used is 5 ppm to 500 ppm with respect to the olefin in a molar ratio.

As conditions at the time of superposition | polymerization, superposition | polymerization temperature is 30-150 degreeC normally, Preferably it is 50-10.
0 ° C. The polymerization pressure is normal pressure to 5 MPa, preferably normal pressure to 4 MPa. In the polymerization of the present invention, hydrogen can be used for the purpose of adjusting the molecular weight of the polymer.
As the monomer used, not only ethylene and propylene alone, but also a monomer copolymerizable with ethylene and propylene, for example, ethylene, propylene, 1-butene, 1-hexene, etc. may be used in the copolymerization. it can.
As a homopolymer composed of the olefin of the present invention or a copolymer component composed of the olefin and another olefin (for example, ethylene and propylene), a melt flow rate (MFR) (MFR) useful as a guide for processing in place of molecular weight ( g / 10 min), MFR of about 0.1 to 1,000 can be arbitrarily polymerized.

  Hereinafter, the present invention will be described more specifically based on examples, but in contrast to the examples of the present invention and comparative examples, the rationality and significance of the constituent elements of the present invention and the usefulness and superiority of the present invention. It demonstrates the sex.

The physical properties of the polymer obtained by the present invention were measured by the following method.
(1) Ethylene content by ¹³ C-NMR
The ethylene content is a value determined by analyzing a ¹³ C-NMR spectrum according to the following conditions by a proton complete decoupling method.
Model: manufactured by JEOL Ltd./GSX-400 or equivalent device (carbon nuclear resonance frequency of 100 MHz or more) Solvent: o-dichlorobenzene + heavy benzene (4: 1 (volume ratio)) Concentration: 100 mg / mL Temperature: 130 ℃ Pulse angle: 90 ° Pulse interval: 15 seconds Integration count: More than 5,000 times

For example, the assignment of the spectrum is, for example, Macromolecules 17, 1950 (19
84) or the like. The attribution of spectra measured under the above conditions is as shown in Table 1. Table 1 Symbols such as S _{alpha alpha} in accordance with notation Carman et al (Macromolecules 10,536 (1977)), P represents respectively the methyl carbon, S is methylene carbon, T is a methine carbon.

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six types of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. As described in Macromolecules 15, 1150 (1982) and the like, the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore,
[PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is.

Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ . By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
In addition, a small amount of propylene heterogeneous bonds (2,1-bonds and / or 1,3-bonds) are contained, which may cause minute peaks. In order to obtain an accurate ethylene content, it is necessary to include these peaks derived from heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds, and the amount of heterogeneous bonds is small. Therefore, the ethylene content of the present invention is determined using the relational expressions (1) to (7) as in the case of analysis in the case where the heterogeneous bond is not substantially included.
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = [(28 × X / 100) / {28 × X / 100 + 42 × (1-X / 100)}] × 100 where X is the ethylene content in mol%. .

(2) Melt flow rate (MFR): determined in accordance with JIS K7210 (230 ° C., 2.16 kg load).

(3) Determination of content of isovaleric acid When carbon dioxide remains in the raw material olefin, isovaleric acid is generated as a by-product due to the presence of triisobutylaluminum added as an optional component to the polymerization system. Causes off-flavors. The presence or absence of carbon dioxide impurities in the olefin raw material can be verified by a sensory test for off-flavors based on the sense of smell of the product polymer.
B) Determination of isovaleric acid 1 g of a sample was weighed into a headspace gas chromatography vial and heated in an oven at 175 ° C. for 30 minutes. Next, a solid-phase microextraction fiber was inserted, volatile components generated from the sample were collected in the fiber, and the collected components were measured by GC / MS. On the other hand, a standard solution of isovaleric acid was prepared, measured in the same manner as described above, and an isovaleric acid calibration curve was prepared and used for the determination of isovaleric acid in the sample.
B) Sensory test method 10 g of polymer powder dried in a nitrogen stream at 80 ° C. for 3 hours is immediately put into a 100 cc glass bottle with a stopper, and the odor level is given by 10 examiners who do not have a preference for smoking. Was evaluated according to the following criteria.
○: 0 inspectors who reported unpleasant odor △: 1-2 inspectors who reported unpleasant odor ×: 3-10 inspectors who reported unpleasant odor

[Example 1]
[Production of solid catalyst]
(I) Silicate Chemical Treatment Using a glass separable flask equipped with a 3 liter stirring blade, 1,130 ml of distilled water was added slowly, followed by 750 g of concentrated sulfuric acid (96%), and montmorillonite (Mizusawa) was added. Chemical Co., Ltd. Benclay SL; average particle size 25 μm, particle size distribution 10-60 μm, composition (weight%): Al 8.45, Mg 2.14, Fe 2.34, Si 32.8, Na 2.62) are dispersed in 300 g, 90 ° C. The temperature was raised over 1 hour, maintained at that temperature for 5.5 hours, and then cooled to 50 ° C. over 1 hour. This slurry was filtered under reduced pressure to recover the cake. Further, this cake was washed with distilled water until the pH of the final washing solution exceeded 3.5, and dried overnight at 110 ° C. in a nitrogen atmosphere.

(Ii) Preparation of Solid Catalyst The following operation was performed using a solvent and a monomer that were deoxygenated and dehydrated under an inert gas. The previously chemically treated montmorillonite was dried at 200 ° C. under reduced pressure for 2 hours. 21. Chemically treated montmorillonite obtained above in a glass reactor having an internal volume of 500 ml
0 g was weighed, 73.7 ml of heptane and 126.3 ml (50.0 mmol) of a heptane solution of trinormal octyl aluminum were added, and the mixture was stirred at room temperature for 1 hour. Thereafter, it was washed with heptane, and finally the slurry amount was adjusted to 200.0 ml.
Next, rac-dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl] synthesized according to the same synthesis method as in Example 1 of JP-A-11-240909. }] 87 ml of mixed heptane was added to 218 mg (0.3 mmol) of zirconium, and after sufficient stirring, 4.25 ml of a heptane solution of triisobutylaluminum (0.706 M) was added and reacted at room temperature for 1 hour. Then, in addition to the previously prepared silicate slurry, after stirring for 1 hour, mixed heptane was added to prepare 500 ml.
Subsequently, as a prepolymerization, the silicate / metallocene complex slurry prepared previously was introduced into a stirring autoclave having an internal volume of 1.0 liter that was sufficiently substituted with nitrogen. When the temperature was stabilized at 40 ° C., purified propylene after removing impurities was supplied at a rate of 10 g / hour to maintain the temperature. After 4 hours, the supply of propylene was stopped, the temperature was raised to 50 ° C., and then maintained for another 2 hours. The prepolymerized catalyst slurry was recovered with a siphon, and about 300 ml of the supernatant was removed, followed by drying at 45 ° C. under reduced pressure. By this operation, a prepolymerized catalyst containing 1.9 g of polypropylene per 1 g of catalyst was obtained.

[Ethylene hybrid adsorbent treatment]
AZ-300 (# 7 × 14 1.) is a hybrid adsorbent composed of activated alumina having an average pore diameter of 1 to 100 nm and zeolite having an average pore diameter of 0.9 nm in a packed tower having an inner diameter of 78 mm and a height of 1,300 mm. 4 kg of 4-2.8 nmφ UOP / Union Showa) was filled.
Next, this packed tower was dried at 250 ° C. under nitrogen flow for 6 hours. Then, ethylene containing 100 vol ppm of carbon dioxide was passed through the packed tower at a flow rate of 400 g / hour at a temperature of 20 ° C. and used for copolymerization of ethylene / propylene. Propylene used was similarly treated with a hybrid adsorbent.

[Ethylene / propylene copolymerization]
The inside of the stirred autoclave with an internal volume of 3 L was sufficiently substituted with separately purified propylene having a carbon dioxide content below the detection limit, and then 2.81 ml of triisobutylaluminum heptane solution (2.02M) was added at room temperature, 25 ml, 16.5 g of purified ethylene, and then 750 g of purified liquid propylene were introduced, and the temperature in the tank was raised to 70 ° C. While maintaining the temperature in the tank at 70 ° C., 1 ml of the normal polymerization heptane slurry (10 mg-catalyst / ml) of the pre-polymerized catalyst obtained above was used, that is, 10 mg (excluding the weight of the pre-polymerized polymer) as a catalyst with argon. The mixture was injected and polymerized at 70 ° C. for 1 hour. After polymerization for a specified time, 10 ml of ethanol was injected into the autoclave with argon, and the remaining gas was purged. The obtained polymer was dried at 110 ° C. for 1 hour.
As a result, about 186 g of polymer was obtained. The MFR was 3.3 (g / 10 min), and the ethylene content was 1.9 (% by weight). The polymerization results are shown in Table 2.

[Example 2]
The experiment was performed in the same manner as in Example 1 except that hydrogen was changed to 100 ml.

[Comparative Example 1]
In the purification step of ethylene (and propylene) in Example 1, the experiment was performed in the same manner as in Example 2 except that the adsorbent used was changed to Selexsorb COS (alumina-based adsorbent / BASF).

[Comparative Example 2]
The experiment was performed in the same manner as in Example 1 except that no purification catalyst treatment was performed on ethylene and propylene.
[Comparative Example 3]
Experiments were conducted in the same manner as in Example 2 except that no purification catalyst treatment was performed on ethylene and propylene.

[Consideration by comparison of results of Examples and Comparative Examples]
As is apparent from Table 2 above, in Examples 1 and 2 using the olefin polymerization method of the present invention, the contact conditions between the olefin of the present invention and the adsorbent were satisfied. The polymerization activity of the catalyst for use is increased, and a reduction in catalyst cost can be expected. Furthermore, the generation of isovaleric acid designated as a specific malodorous substance, which is a reaction product of triisobutylaluminum and carbon dioxide, can be suppressed to a very small amount.
On the other hand, in Comparative Examples 2 and 3 in which carbon dioxide was not removed and the contact conditions of the present invention were not satisfied, the polymerization activity was low due to the effect of carbon dioxide in ethylene, and this resulted in an unpleasant odor for isovaleric acid. It was inferior to the Example of invention.
In Comparative Example 1, a certain amount of carbon dioxide was removed by the introduced adsorbent, but it was not sufficient. Compared with Examples 1 and 2, the isovaleric acid concentration was sufficiently reduced even though the polymerization activity was good. However, the effect of carbon dioxide is suggested.
As described above, the rationality and significance of the constituent elements of the present invention and the usefulness and superiority of the present invention have been demonstrated in contrast with the examples of the present invention and the comparative examples.

The olefin polymerization method of the present invention exhibits a very high polymerization activity in the polymerization of olefins using a metallocene catalyst, even when the raw material olefin contains carbon dioxide, an impurity that poisons the catalyst. Furthermore, isovaleric acid that can be generated by reaction with triisobutylaluminum can be suppressed to a very small amount. Therefore, it is possible to stably produce a high-quality polymer at a high yield, which can be said to be a commercially valuable technique.

Claims (11)

It is characterized in that a raw material olefin containing carbon dioxide as an impurity is brought into contact with a hybrid adsorbent composed of a mixture of activated alumina and zeolite, and after purifying the raw material olefin, the purified olefin is brought into contact with a transition metal complex catalyst for polymerization. An olefin polymerization method. The olefin polymerization method according to claim 1, wherein the raw material olefin further contains 5 volppm or less of an acetylene compound as an impurity. The olefin polymerization method according to claim 1, wherein the transition metal complex catalyst is a metallocene catalyst. The olefin polymerization method according to claim 3, wherein the metallocene catalyst is supported on an ion-exchange layered silicate. The olefin polymerization method according to any one of claims 1 to 4, wherein the hybrid adsorbent is pretreated at a temperature of 100 to 650 ° C. The average pore diameter of activated alumina is 1 to 100 nm, and the average pore diameter of zeolite is 0.2 to 1 nm. The olefin polymerization method according to any one of claims 1 to 5, wherein The method for polymerizing an olefin according to any one of claims 1 to 6, wherein the contact temperature between the raw material olefin containing carbon dioxide as an impurity and the hybrid adsorbent is 0 to 100 ° C. The olefin polymerization method according to any one of claims 1 to 7, wherein the raw material olefin contains 100 volppm or less with carbon dioxide as an impurity. Before and after contacting the raw material olefin containing carbon dioxide as an impurity and the hybrid adsorbent, at least one of the following (1) to (3) is brought into contact with: The method for polymerizing olefins according to Item.
(1) Zeolite (2) Metal oxide or composite oxide of metal oxide (3) Activated alumina The olefin polymerization method according to any one of claims 1 to 9, wherein the raw material olefin is ethylene and / or propylene. The olefin polymerization method according to claim 10, wherein the olefin polymer is a propylene / ethylene copolymer having an ethylene content of 6 wt% or less.