Method for purifying olefin polymer and method for producing purified olefin polymer

Abstract

To provide a method for efficiently removing residual metal components from olefinic polymers, containing metals such as aluminum.SOLUTION: A method for purifying olefinic polymers includes the step of bringing olefinic polymers, containing metal compounds, into contact with at least one compound selected from acetylacetone, acetylacetone derivatives and 2'-hydroxy acetophenone, to treat the resulting product at a specific temperature or higher.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for purifying an olefin polymer, which reduces the amount of aluminum compounds and the like contained in the olefin polymer, and to a method for producing a purified olefin polymer in which the amount of aluminum compounds and the like is reduced when the olefin polymer contains aluminum compounds and the like. [Background technology]

[0002] It is known that alkylaluminum and its partial hydrolyzate, aluminoxane, act as a co-catalyst to activate the transition metal compound, which is the main catalyst, in the production of olefin polymers.

[0003] Here, as a method for producing an olefin polymer having a good particle shape as the main catalyst and enabling stable production, a production method using a supported catalyst in which a transition metal compound and / or an aluminoxane is supported on a solid inorganic support such as silica, alumina, silica-alumina, or magnesium chloride is used as the main catalyst. However, for the purpose of further improving the polymerization activity and the control of stereoregularity, the use of an aluminoxane itself as a support (i.e., the use of a solid aluminoxane) has also been investigated (see, for example, Patent Document 1).

[0004] Olefin polymers produced using transition metal compounds tend to contain very small amounts of metal components derived from the main catalyst and co-catalyst as foreign matter, which can deteriorate the physical properties of the polymer depending on the application. For this reason, trace amounts of metal components contained in the olefin polymer are removed as needed (see, for example, Patent Document 2 and Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 123212 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-075840 [Patent Document 3] Japanese Patent Application Publication No. 2019-172740 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, various products have been required to have higher performance and quality, and the quality requirements for the materials used in them have also become more sophisticated and pure. While semiconductors are an example of a successful example of high-purity technology in the past, the demand for high quality and purity is spreading to other materials as well.

[0007] For example, as electrical components become increasingly smaller and more sophisticated, electrical insulating materials are often required to have higher electrical insulating properties. From the perspective of carbon neutrality, typical applications include large-capacity batteries and capacitors, more specifically, batteries and capacitors for electric vehicles and other vehicles.

[0008] Separator films are used as components for batteries and capacitors, and polyolefin films such as polyethylene and polypropylene films are primarily used due to their high insulating properties. The polyolefins used as raw materials are often produced using catalysts containing compounds containing transition metal elements from Groups 4 or 5 of the periodic table and compounds containing metal elements from Groups 1 to 3 of the periodic table. Therefore, it is preferable to remove these catalysts from the perspective of maintaining insulating properties. Removal of metal residues is particularly important in the case of large-capacity capacitors, as there is a possibility of short circuits due to the metal residues.

[0009] For some applications, such as automotive applications, heat resistance is also an important requirement. For this reason, capacitor films using polyolefins with high melting points are considered suitable. However, the production of high-melting-point polyolefins tends to result in low polymerization activity, which tends to increase the amount of metal residues.

[0010] Not limited to the above applications, it can be said that the need for high quality and high purity components is a requirement of the times. A known method for removing the metal residues involves contacting the metal with a compound that easily forms a complex with the metal, such as acetylacetone, to form a metal complex, which is then dissolved in an organic solvent, etc. Studies by the present inventors have revealed that even with this method, a small amount of metal residue may remain.

[0011] It has been reported that one type of such complex, an aluminum acetylacetonato complex, has a melting point of 190 to 200° C. and a sublimation temperature of 170 to 180° C. It is also known that such complexes are prone to denaturation in air, and may be difficult to evaporate or sublimate (for example, JP-A No. 2000-203988).

[0012] Therefore, a method of treating the olefin polymer at a temperature higher than the above to evaporate and sublimate the metal residue may be considered, but such a temperature is often higher than the melting point of the olefin polymer, resulting in the polymer melting. The molten resin may be difficult to handle, and in addition, from the viewpoint of the specific surface area, it may be difficult to remove the above-mentioned residue. Therefore, a method of removing the metal residue that does not involve melting the resin as much as possible is preferable.

[0013] An object of the present invention is to provide a new method for efficiently removing metal residues derived from a known olefin polymerization catalyst from an olefin polymer produced using the catalyst. [Means for solving the problem]

[0014] The present inventors have conducted research to solve the above problems. As a result, they have found that the above problems can be solved by the following methods, and have completed the present invention. The present invention relates to, for example, the following [1] to [8].

[0015] [1] a first step of contacting, under an inert gas atmosphere, an olefin polymer composition containing an olefin polymer having a melting point and / or glass transition temperature of 110°C or higher, a transition metal compound containing a metal element selected from elements of Groups 3 to 11 of the periodic table, and an organometallic compound containing a metal element selected from elements of Groups 1, 2, and 13 of the periodic table, with at least one compound selected from the group consisting of acetylacetone, acetylacetone derivatives, and 2'-hydroxyacetophenone to obtain a contact product; a second step of maintaining the contact product in an inert gas atmosphere at a temperature of 100°C or higher and lower than the melting point of the olefin polymer for 0.1 to 100 hours; A method for purifying an olefin polymer having the formula:

[0016] [2] The method for purifying an olefin polymer according to [1] above, wherein the olefin polymer is a polymer of at least one olefin selected from ethylene and an α-olefin having 3 to 20 carbon atoms.

[0017] [3] The method for purifying an olefin polymer according to [1] or [2] above, wherein the olefin polymer has a structural unit derived from 4-methyl-1-pentene.

[0018] [4] The method for purifying an olefin polymer according to any one of the above [1] to [3], wherein the transition metal compound is a metallocene compound.

[0019] [5] The method for purifying an olefin polymer according to any one of the above [1] to [4], wherein the organometallic compound is a solid aluminoxane.

[0020] [6] The method for purifying an olefin polymer according to [5] above, wherein the solid aluminoxane is solid polymethylaluminoxane.

[0021] [7] The method for purifying an olefin polymer according to any one of [1] to [6] above, wherein the olefin polymer composition contains an olefin polymer produced using an olefin polymerization catalyst in which a transition metal compound is supported on solid aluminoxane.

[0022] [8] A step of preparing a crude olefin polymer containing an aluminum compound in an amount exceeding 4.0 ppm by mass in terms of aluminum atoms and having a melting point and / or glass transition temperature of 110°C or higher; a step of purifying the crude olefin polymer by any one of the methods for purifying an olefin polymer according to any one of [1] to [7] above, to produce a purified olefin polymer having an aluminum content of 3.0 mass ppm or less in terms of aluminum atoms. A method for producing a purified olefin polymer, comprising: [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a method for efficiently removing metal components contained in an olefin polymer produced using an olefin polymerization catalyst containing a transition metal compound and an organometallic compound, and a method for producing an olefin polymer with a reduced amount of metal residue. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 shows the holding temperatures in the second step and the amounts of aluminum remaining in the purified olefin polymer compositions in Examples 1 and 2 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the present invention, the term "polymerization" may be used to mean not only homopolymerization but also copolymerization, and the term "polymer" may be used to mean not only homopolymer but also copolymer.

[0026] The method for purifying an olefin polymer of the present invention comprises a first step of contacting an olefin polymer composition containing an olefin polymer, a transition metal compound, and an organometallic compound with at least one compound selected from the group consisting of acetylacetone, acetylacetone derivatives, and 2'-hydroxyacetophenone (hereinafter also referred to as "compound α") in an inert gas atmosphere to obtain a contact product, and a second step of holding the contact product in an inert gas atmosphere at a temperature of 100°C or higher and lower than the melting point of the olefin polymer for 0.1 to 100 hours.

[0027] The production method of the present invention is also a method for producing a purified olefin polymer having a metal residue content of 3.0 mass ppm or less from a crude olefin polymer containing a relatively large amount of metal residue by the above-mentioned purification method.

[0028] (First step) In the present invention, the compound α is a so-called decalcifying agent. The first step is a step of contacting the olefin polymer composition with compound α in an inert gas atmosphere to convert a metal residue contained in the olefin polymer composition into a metal complex. For example, one preferred embodiment of contacting the olefin polymer composition with compound α is a step of adding compound α to a polymerization reactor containing a liquid containing an olefin polymer obtained after the polymerization reaction.

[0029] When the above contact operation is carried out in a slurry state, it is also possible to simultaneously carry out a solid-liquid separation operation by filtration, decantation, or the like, as described below, for the purpose of removing the metal complex eluted into the medium.

[0030] The olefin polymer composition is usually a slurry containing an olefin polymer, a transition metal compound, and a solid aluminoxane as an organometallic compound. The method of the present invention is often suitable for such a slurry. The content of the olefin polymer in the slurry is usually 5 to 50 mass%, preferably 10 to 35 mass%. For convenience, the following description will be mainly based on an embodiment in which the organometallic compound is a solid aluminoxane.

[0031] In the slurry, examples of the dispersion medium include inert hydrocarbon media, specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane.

[0032] For example, by contacting a slurry containing olefin polymer particles, a transition metal compound, a solid aluminoxane, and a dispersion medium with compound α, it is possible to transfer the aluminum and other catalyst components remaining in the olefin polymer particles to the dispersion medium, and thus the aluminum can be removed by a separation treatment described below.

[0033] In the contact of the olefin polymer composition with compound α, the lower limit of the amount of compound α used is preferably 5 mol, more preferably 50 mol, and even more preferably 200 mol per mol of aluminum (Al) contained in the olefin polymer composition. The upper limit of the amount of compound α used is not particularly limited, but is, for example, 2000 mol per mol of aluminum (Al). This embodiment is preferable from the viewpoints of the removability of residual aluminum and the cost of compound α.

[0034] The temperature at which the olefin polymer composition is brought into contact with the compound α is usually 25° C. or higher, preferably 40° C. or higher, more preferably 50° C. or higher, and usually 140° C. or lower, preferably 120° C. or lower, more preferably 90° C. or lower. Such an embodiment is preferred from the viewpoints of the removability of residual aluminum and the recovery rate of the olefin polymer.

[0035] The contact is carried out by, for example, mixing the olefin polymer composition with compound α as described above, but from the viewpoint of improving the deashing efficiency, it is preferable to stir the resulting mixture. The stirring time is, for example, 0.5 to 24 hours, preferably 1 to 12 hours.

[0036] The first step is carried out in an inert gas atmosphere. The inert gas is a gas that is unlikely to cause denaturation of the transition metal compound, organometallic compound, or metal complex. Examples of the inert gas include gases of Group 18 elements of the periodic table, as well as nitrogen and hydrocarbon gases. Considering cost and environmental impact, nitrogen is most preferable. By carrying out the first step in such an inert gas atmosphere, it is possible to prevent the inclusion of air and the like, and to prevent the denaturation of the transition metal compound, organometallic compound, or metal complex due to oxygen in the air.

[0037] The inert gas atmosphere may contain other gases than the inert gas described above, provided that the purpose of the inert gas atmosphere is not impaired. The content of the inert gas in the inert gas atmosphere is preferably 50 vol% or more, more preferably 70 vol% or more, even more preferably 80 vol% or more, and particularly preferably 90 vol% or more. The preferred upper limit is, of course, 100 vol%.

[0038] After contacting the olefin polymer composition with compound α, the olefin polymer can be separated (separation treatment) from the resulting contact product (i.e., a mixture of the olefin polymer composition and compound α) by, for example, decantation, pressure filtration, vacuum filtration, centrifugation, etc. In this case, known purification treatments such as washing with an inert hydrocarbon medium and drying treatment may be carried out, if necessary.

[0039] In the olefin polymer separated as described above, most of the metal components (mainly aluminum in the above case) are significantly reduced in the separated liquid, but small amounts of these components may remain in the wet solid portion.

[0040] In the first step, the olefin polymer composition is brought into contact with compound α, whereby a transition metal compound or an organometallic compound forms a metal complex with compound α. This metal complex is easily soluble in the dispersion medium, so as described above, a solid-liquid separation step may or may not be carried out. Needless to say, a mode in which a dispersion medium is used and a solid-liquid separation step is carried out is preferred.

[0041] (Second step) The production process of an olefin polymer usually often includes a drying step for removing the dispersion medium and the like, and from the viewpoint of maintaining the shape of the olefin polymer and avoiding the high cost of heating, it is generally considered preferable to carry out drying at a temperature of less than 100° C. In this case, drying may be carried out in a reduced pressure environment or under a gas stream.

[0042] The second step in the present invention is similar to the drying step described above, but is characterized in that the product obtained by contacting the olefin polymer composition with compound α in the first step (hereinafter also referred to as the "contact product") is maintained at a temperature of 100°C or higher and below the melting point of the olefin polymer. The lower limit is preferably 105°C, more preferably 110°C, even more preferably 115°C, and particularly preferably 120°C. On the other hand, the upper limit is preferably less than 170°C, more preferably 165°C, even more preferably 160°C, and particularly preferably 155°C. The present inventors have surprisingly found that by adding a step of maintaining the temperature at such a temperature, the amount of metal residue can be significantly reduced.

[0043] As mentioned above, the melting point of aluminum acetylacetonato complex (Al(acac)3) is 190-200°C, and its sublimation temperature is 170-180°C. In the method of the present invention, the amount of metal (particularly aluminum; the same applies below) residue can be reduced even at temperatures lower than the melting point and sublimation temperature. The exact reason why this phenomenon occurs is unknown, but the inventors speculate as follows.

[0044] Sublimation of an aluminum acetylacetonato complex requires a relatively large amount of energy, and is generally difficult to achieve. On the other hand, the transition metal compound or organometallic compound in the olefin polymer composition of the present invention is likely to be finely dispersed around the olefin polymer and easily absorb energy due to heating, so sublimation may occur even at temperatures below the sublimation temperature. Furthermore, when a dispersion medium is used in combination, in addition to the effect of fine dispersion, the energy absorption efficiency is increased, making sublimation more likely, and therefore sublimation may occur at low temperatures. Furthermore, if the temperature is at the gasification temperature of the dispersion medium, the sublimate may be easily entrained in the gas and separated.

[0045] For these reasons, the method for purifying an olefin polymer of the present invention can reduce the amount of metal residues to a higher level than ever before (which is equivalent to being able to purify an olefin polymer). The time required for the second step is 0.1 to 100 hours. The lower limit is preferably 0.5 hours, more preferably 1 hour, and even more preferably 2 hours. On the other hand, the upper limit is preferably 70 hours, more preferably 50 hours, and even more preferably 40 hours. Within the above-mentioned time range, metal residues can be efficiently reduced.

[0046] The second step of the present invention is also carried out in the inert gas atmosphere. By carrying out the step in the inert gas atmosphere, it is thought that the denaturation of the metal complex can be suppressed, thereby enabling efficient removal of the metal by sublimation. In the present invention, the first and second steps may be collectively referred to as a demineralization step or demineralization treatment.

[0047] In the present invention, the above-mentioned demineralization treatment can efficiently remove residual aluminum, particularly aluminum derived from the solid aluminoxane in the olefin polymer. For example, the above-mentioned demineralization treatment can achieve a demineralization rate of aluminum derived from the solid aluminoxane of 80% or more, preferably 90% or more, and more preferably 95% or more. Here, the demineralization rate is defined as 100 - (residual Al [ppm by mass] derived from the solid aluminoxane after demineralization / Al [ppm by mass] derived from the solid aluminoxane before demineralization × 100).

[0048] <Compound α> In the present invention, aluminum derived from solid aluminoxane can be efficiently removed from an olefin polymer composition by using at least one compound α selected from the group consisting of acetylacetone, acetylacetone derivatives, and 2'-hydroxyacetophenone.

[0049] Hereinafter, acetylacetone and acetylacetone derivatives will be collectively referred to as “acetylacetone-based compounds.” Examples of acetylacetone-based compounds include compounds represented by the following formula:

[0050] [ka]

[0051] In the formula, R 1 and R 2 are each independently a hydrocarbon group, and R 3 are each independently a hydrogen atom or a hydrocarbon group.

[0052] The number of carbon atoms in the hydrocarbon group is usually 6 or less, preferably 3 or less, and more preferably 2 or less. Examples of the hydrocarbon group include alkyl groups, and specific examples include methyl groups, ethyl groups, and propyl groups.

[0053] Specifically, preferred acetylacetone compounds are acetylacetone, 3-ethyl-2,4-pentanedione, and 3,5-heptanedione. One or more types of compound α can be used.

[0054] <Olefin polymer> In the present invention, the olefin polymer to be deashed is a polymer obtained by polymerizing one or more olefins, and may be a homopolymer or a copolymer. Its melting point and / or glass transition temperature is 110°C or higher, preferably 120°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, particularly preferably 180°C or higher, and especially preferably 190°C or higher. The preferred upper limit of the melting point and / or glass transition temperature is not particularly limited, but is preferably 300°C, more preferably 280°C, and even more preferably 260°C.

[0055] The olefin is preferably at least one selected from ethylene and α-olefins having 3 to 20 carbon atoms, more preferably at least one selected from ethylene and α-olefins having 3 to 10 carbon atoms.

[0056] The α-olefin may be linear or branched. For example, propylene, 1-butene, 2-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-icosene may be used. Among these, it is preferable to use at least 4-methyl-1-pentene.

[0057] Furthermore, the polymerization can also be carried out by allowing at least one selected from ethylene and an α-olefin having 3 to 20 carbon atoms to coexist in the reaction system with at least one selected from a cyclic olefin, an olefin having a polar group, a vinyl compound having a terminal hydroxyl group, an aromatic vinyl compound, and a polyene.

[0058] The olefin polymer is preferably a polymer having structural units derived from 4-methyl-1-pentene, and more preferably a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene with at least one selected from ethylene and α-olefins having 3 to 20 carbon atoms (excluding 4-methyl-1-pentene).

[0059] An example of an olefin polymer is a polymer containing 50 to 100 mol %, preferably 55 to 100 mol %, and more preferably 80 to 100 mol % of 4-methyl-1-pentene-derived structural units relative to all monomer-derived structural units. The content can be measured by nuclear magnetic resonance spectroscopy, or, when a standard substance is available, infrared spectroscopy.

[0060] The olefin polymer in the olefin polymer composition is an olefin polymer produced using an olefin polymerization catalyst, as described below. The olefin polymerization catalyst contains a transition metal compound and a solid aluminoxane. The transition metal compound is preferably supported on the solid aluminoxane.

[0061] When the olefin polymerization catalyst is used during polymerization, solid aluminoxane (particularly aluminum derived from the aluminoxane) remains in the olefin polymer, and therefore the above-mentioned deashing treatment is carried out in the present invention. By carrying out the deashing treatment, an olefin polymer with a reduced amount of aluminum can be easily obtained.

[0062] <Transition metal compounds> In the present invention, the transition metal compound is preferably a metallocene compound. Examples of metallocene compounds include those disclosed in International Publication Nos. 2005 / 121192, 2014 / 050816, 2014 / 050817, 2014 / 123212, and 2017 / 150265. Preferred examples include the bridged metallocene compounds disclosed in International Publication Nos. 2014 / 050816, 2014 / 050817, 2014 / 123212, and 2017 / 150265, but the scope of the present invention is not limited thereto.

[0063] The metallocene compound is preferably a compound represented by the general formula [A1].

[0064] [ka]

[0065] In formula [A1], R 1a ~R 14a are each independently a hydrogen atom, a halogen atom, a hydrocarbon group, a heteroatom-containing hydrocarbon group, or a silicon-containing group, and R 1a ~R 14a Any two of the substituents may be bonded to each other to form a ring.

[0066] In formula [A1], M is a transition metal of Group 4 of the periodic table; Q is a halogen atom, a hydrocarbon group, an anionic ligand, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, or a neutral ligand capable of coordinating with a lone electron pair; j is an integer of 1 to 4; and when j is an integer of 2 or greater, Qs may be the same or different from each other.

[0067] The metallocene compound has high polymerization activity and can give an olefin polymer with high stereoregularity and molecular weight, and therefore the compound represented by formula [A2] is more preferred.

[0068] [ka]

[0069] In formula [A2], R 1 ~R 16 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group, a heteroatom-containing hydrocarbon group, or a silicon-containing group, and R 1 ~R 16 Any two of the substituents may be bonded to each other to form a ring.

[0070] In formula [A2], M is a transition metal of Group 4 of the periodic table; Q is a halogen atom, a hydrocarbon group, an anionic ligand, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, or a neutral ligand capable of coordinating with a lone electron pair; j is an integer of 1 to 4; and when j is an integer of 2 or greater, Qs may be the same or different from each other.

[0071] 〈R 1a ~R 14a and R 1 ~R 16 〉 R 1a ~R 14a and R 1 ~R 16 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1a ~R 14a and R 1 ~R 16 Examples of the hydrocarbon group in include a linear hydrocarbon group, a branched hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic unsaturated hydrocarbon group, and a group in which one or more hydrogen atoms of a saturated hydrocarbon group are substituted with a cyclic unsaturated hydrocarbon group. The number of carbon atoms in the hydrocarbon group is usually 1 to 20, preferably 1 to 15, and more preferably 1 to 10.

[0072] Examples of the linear hydrocarbon group include linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decanyl group; and linear alkenyl groups such as an allyl group.

[0073] Examples of branched hydrocarbon groups include branched alkyl groups such as an isopropyl group, a tert-butyl group, a tert-amyl group, a 3-methylpentyl group, a 1,1-diethylpropyl group, a 1,1-dimethylbutyl group, a 1-methyl-1-propylbutyl group, a 1,1-propylbutyl group, a 1,1-dimethyl-2-methylpropyl group, and a 1-methyl-1-isopropyl-2-methylpropyl group.

[0074] Examples of cyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and methylcyclohexyl; and polycyclic groups such as norbornyl, adamantyl, and methyladamantyl.

[0075] Examples of cyclic unsaturated hydrocarbon groups include aryl groups such as phenyl, tolyl, naphthyl, biphenyl, phenanthryl, and anthracenyl; cycloalkenyl groups such as cyclohexenyl; and polycyclic unsaturated alicyclic groups such as 5-bicyclo[2.2.1]hept-2-enyl.

[0076] Examples of groups in which one or more hydrogen atoms of a saturated hydrocarbon group are substituted with a cyclic unsaturated hydrocarbon group include groups in which one or more hydrogen atoms of an alkyl group, such as a benzyl group, a cumyl group, a 1,1-diphenylethyl group, or a triphenylmethyl group, are substituted with an aryl group.

[0077] R 1a ~R 14a and R 1 ~R 16Examples of the heteroatom-containing hydrocarbon group in include alkoxy groups such as methoxy and ethoxy, aryloxy groups such as phenoxy, and oxygen-containing hydrocarbon groups such as furyl; amino groups such as N-methylamino, N,N-dimethylamino, and N-phenylamino; nitrogen-containing hydrocarbon groups such as pyrryl; and sulfur-containing hydrocarbon groups such as thienyl. The number of carbon atoms in the heteroatom-containing hydrocarbon group is usually 1 to 20, preferably 2 to 18, and more preferably 2 to 15. However, silicon-containing groups are excluded from the heteroatom-containing hydrocarbon group.

[0078] R 1a ~R 14a and R 1 ~R 16 Examples of the silicon-containing group in the formula include groups represented by the formula -SiR3 (wherein each of the multiple Rs is independently an alkyl group or a phenyl group having 1 to 15 carbon atoms), such as a trimethylsilyl group, a triethylsilyl group, a dimethylphenylsilyl group, a diphenylmethylsilyl group, and a triphenylsilyl group.

[0079] R 1a ~R 14a and R 1 ~R 16 Among the substituents up to 1 and R 2 , R 2 and R 3 , R 4 and R 6 , R 5 and R 7 , R 6 and R 8 , R 7 and R 8 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 , R 13 and R 14 , R 14 and R 15 , R 15 and R 16 ) may be bonded to each other to form a ring, and for example, R4 and R 5 may be bonded to each other to form a ring, and R 6 and R 7 may be bonded to each other to form a ring, and R 1 and R 8 may be bonded to each other to form a ring, and R 3 and R 5 may be bonded to each other to form a ring. The ring formation may occur at two or more positions in the molecule.

[0080] In this specification, examples of the ring (additional ring) formed by bonding two substituents together include an alicyclic ring, an aromatic ring, and a heterocyclic ring.Specific examples include a cyclohexane ring, a benzene ring, a hydrogenated benzene ring, a cyclopentene ring, a heterocyclic ring such as a furan ring, a thiophene ring, and the like, and corresponding hydrogenated heterocyclic rings, and preferred are a cyclohexane ring, a benzene ring, and a hydrogenated benzene ring.Furthermore, such a ring structure may further have a substituent such as an alkyl group on the ring.

[0081] A preferred embodiment of the compound represented by formula [A2] will be described below. R 1 and R 3 is preferably a hydrogen atom from the viewpoint of stereoregularity. R 4 , R 5 , R 6 and R 7 At least one selected from R is preferably a hydrocarbon group, a heteroatom-containing hydrocarbon group, or a silicon-containing group, 5 is more preferably a hydrocarbon group, and R 5 is more preferably an alkyl group having 2 or more carbon atoms, such as a linear alkyl group or a branched alkyl group, a cycloalkyl group, or a cycloalkenyl group, and R 5 is particularly preferably an alkyl group having two or more carbon atoms. 4 , R 6 and R 7 is also preferably a hydrogen atom.

[0082] Alternatively, R 5 and R 7 are more preferably bonded to each other to form a ring, and the ring is particularly preferably a six-membered ring such as a cyclohexane ring. 4 and R 6 is, for example, a hydrogen atom.

[0083] R 8 is preferably a hydrocarbon group, and particularly preferably an alkyl group. R 2 is preferably a hydrocarbon group, a heteroatom-containing hydrocarbon group, or a silicon-containing group, more preferably a hydrocarbon group, even more preferably not an aryl group, particularly preferably a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic saturated hydrocarbon group, and particularly preferably a substituent in which the carbon having a free valence (the carbon bonded to the cyclopentadienyl ring) is a tertiary carbon, because these groups make it possible to produce an olefin polymer with high stereoregularity and high molecular weight.

[0084] R 2 Specific examples of the substituent include a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a tert-pentyl group, a tert-amyl group, a 1-methylcyclohexyl group, and a 1-adamantyl group, more preferably a substituent in which the carbon having a free valence is a tertiary carbon, such as a tert-butyl group, a tert-pentyl group, a 1-methylcyclohexyl group, or a 1-adamantyl group, and particularly preferably a 1-adamantyl group or a tert-butyl group.

[0085] In the formula [A2], the fluorene ring portion is not particularly limited as long as it has a structure obtained from a known fluorene derivative. 9 , R 12 , R 13 and R 16 is preferably a hydrogen atom from the viewpoints of stereoregularity and molecular weight.

[0086] R 10 , R 11 , R 14and R 15 is preferably a hydrogen atom, a hydrocarbon group, an oxygen atom-containing hydrocarbon group or a nitrogen atom-containing hydrocarbon group, more preferably a hydrocarbon group, and even more preferably a hydrocarbon group having 1 to 20 carbon atoms.

[0087] R 10 and R 11 are bonded to each other to form a ring, and R 14 and R 15 may be bonded to each other to form a ring. Examples of such a substituted fluorenyl group include a benzofluorenyl group, a dibenzofluorenyl group, an octahydrodibenzofluorenyl group, a 1,1,4,4,7,7,10,10-octamethyl-2,3,4,7,8,9,10,12-octahydro-1H-dibenzo[b,h]fluorenyl group, a 1,1,3,3,6,6,8,8-octamethyl-2,3,6,7,8,10 Examples of the fluorene include 1,1,4,4,7,7,10,10-octamethyl-2,3,4,7,8,9,10,12-octahydro-1H-dibenzo[b,h]fluorenyl and 1',1',3',6',8',8'-hexamethyl-1'H,8'H-dicyclopenta[b,h]fluorenyl groups, and particularly preferred is 1,1,4,4,7,7,10,10-octamethyl-2,3,4,7,8,9,10,12-octahydro-1H-dibenzo[b,h]fluorenyl. 1,1,4,4,7,7,10,10-octamethyl-2,3,4,7,8,9,10,12-octahydro-1H-dibenzo[b,h]fluorene is also referred to as "octamethylfluorene."

[0088] <M, Q, j> M is a transition metal of Group 4 of the periodic table, preferably Ti, Zr or Hf, more preferably Zr or Hf, and particularly preferably Zr.

[0089] Examples of the halogen atom in Q include fluorine, chlorine, bromine, and iodine. The hydrocarbon group in Q is R 1a ~R 14a and R 1 ~R 16Examples of the hydrocarbon group include the same groups as those in the above, and preferred are alkyl groups such as linear alkyl groups and branched alkyl groups.

[0090] Examples of the anionic ligand in Q include alkoxy groups such as methoxy and tert-butoxy; aryloxy groups such as phenoxy; carboxylate groups such as acetate and benzoate; sulfonate groups such as mesylate and tosylate; and amide groups such as dimethylamide, diisopropylamide, methylanilide, and diphenylamide.

[0091] The neutral conjugated or non-conjugated diene having 10 or less carbon atoms in Q is, for example, s-cis- or s-trans-η 4 -1,3-butadiene, s-cis- or s-trans-η 4 -1,4-diphenyl-1,3-butadiene, s-cis- or s-trans-η 4 -3-Methyl-1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-Dibenzyl-1,3-butadiene, s-cis- or s-trans-η 4 -2,4-Hexadiene, s-cis- or s-trans-η 4 -1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-Ditolyl-1,3-butadiene, s-cis- or s-trans-η 4 -1,4-bis(trimethylsilyl)-1,3-butadiene.

[0092] Examples of the neutral ligand capable of coordinating with the lone electron pair in Q include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine; and ethers such as tetrahydrofuran, diethyl ether, dioxane, and 1,2-dimethoxyethane.

[0093] At least one of Q is preferably a halogen atom or an alkyl group. j is preferably 2. The above is the structure of the transition metal compound, i.e., R 1a ~R 14a , R 1 ~R 16 , M, Q and j have been described as preferred embodiments. In the present invention, any combination of the preferred embodiments is also a preferred embodiment.

[0094] <Organometallic compounds> The organometallic compound of the present invention preferably serves as a cocatalyst for efficiently achieving the polymerization performance of the transition metal compound. It also functions as a scavenger, reacting with and inactivating impurities (compounds that may poison the catalyst) in the reaction system. Examples of such compounds include, without limitation, known compounds having a structure in which a hydrocarbon group, such as an alkyl group, is bonded to a metal of Groups 1, 2, or 13 of the periodic table. Examples of such compounds include, without limitation, known compounds such as trialkylaluminum compounds, alkylaluminum halide compounds, and aluminoxane compounds. Solid aluminoxanes are also useful compounds, and will be described in detail below. The solid aluminoxane functions as a cocatalyst and a catalyst support for the olefin polymerization catalyst.

[0095] The term "solid" means that the aluminoxane remains substantially solid in the reaction environment in which the solid aluminoxane is used. More specifically, for example, when preparing an olefin polymerization solid catalyst component by contacting the components constituting the olefin polymerization catalyst, the aluminoxane is in a solid state in an inert hydrocarbon medium, such as hexane or toluene, used in the reaction under a specific temperature and pressure environment. Furthermore, for example, when performing slurry polymerization using an olefin polymerization catalyst, the aluminoxane contained in the polymerization catalyst is in a solid state in an inert hydrocarbon medium under a specific temperature and pressure environment. The same applies to bulk polymerization in which polymerization is performed in a liquefied olefin instead of the medium, or gas-phase polymerization in which polymerization is performed in an olefin gas.

[0096] The solid aluminoxane preferably contains an aluminoxane having at least one structural unit selected from the structural units represented by formula (1) and the structural units represented by formula (2), more preferably contains an aluminoxane having a structural unit represented by formula (1), and even more preferably contains a polymethylaluminoxane consisting solely of the structural unit represented by formula (1).

[0097] [ka]

[0098] In formula (1), Me is a methyl group. In formula (2), R 1 is a hydrocarbon group having 2 to 20 carbon atoms, preferably a hydrocarbon group having 2 to 15 carbon atoms, and more preferably a hydrocarbon group having 2 to 10 carbon atoms. Examples of the hydrocarbon group include alkyl groups such as ethyl, propyl, n-butyl, pentyl, hexyl, octyl, decyl, isopropyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, 3-methylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, and 2-ethylhexyl; cycloalkyl groups such as cyclohexyl and cyclooctyl; and aryl groups such as phenyl and tolyl.

[0099] The structure of solid aluminoxanes is not necessarily clear, but is generally assumed to have a structure in which the structural units represented by formula (1) and / or formula (2) are repeated about 2 to 50 times, but is not limited to this structure. The structural units may be bonded in various ways, such as linear, cyclic, or cluster-like, and aluminoxanes are generally assumed to consist of one of these or a mixture of these. Alternatively, aluminoxanes may consist solely of structural units represented by formula (1) or formula (2).

[0100] As the solid aluminoxane, solid polymethylaluminoxane is preferred, and solid polymethylaluminoxane consisting only of the constituent unit represented by formula (1) is more preferred. The solid aluminoxane is usually in the form of particles, and the volumetric statistical value D50 is preferably 1 to 500 μm, more preferably 2 to 200 μm, and even more preferably 5 to 50 μm. The volumetric statistical value D50 can be determined by a laser diffraction / scattering method using, for example, an MT3300EX II manufactured by Microtrac.

[0101] The solid aluminoxane preferably has a specific surface area of ​​100 to 1000 m 2 / g, more preferably 300 to 800m 2 The specific surface area can be determined using the BET adsorption isotherm, which utilizes the phenomenon of gas adsorption and desorption on a solid surface.

[0102] The solid aluminoxane functions as a catalyst support, so there is no need to use a solid inorganic support such as silica, alumina, silica-alumina, or magnesium chloride, or a solid organic support such as polystyrene beads, in addition to the solid aluminoxane.

[0103] Solid aluminoxanes can be prepared, for example, by the methods described in WO 2010 / 055652 and WO 2014 / 123212. An example is described below.

[0104] First, an organoaluminum compound represented by AlRa3, such as trimethylaluminum (a specific example of an organoaluminum compound represented by general formula (B-1a) described later) is reacted with an oxygen-containing organic compound in an aromatic hydrocarbon solvent to obtain an aluminum compound having an aluminum-oxygen-carbon bond, which is then thermally decomposed. The molar amount of aluminum atoms in the organoaluminum compound per mole of oxygen atoms in the oxygen-containing organic compound is typically 0.5 to 3.0 moles, preferably 1.0 to 1.7. The thermal decomposition reaction conditions are, for example, a heating temperature of typically 20 to 90°C, preferably 30 to 80°C, and a heating time of typically 5 to 100 hours.

[0105] The resulting reaction solution is then cooled, for example, to about room temperature and reheated to precipitate a solid aluminoxane. Heating conditions include, for example, a heating temperature of typically 80 to 200°C, preferably 90 to 150°C, and a heating time of typically 5 minutes to 24 hours, preferably 1 to 20 hours. The precipitated solid aluminoxane may be washed with a non-aromatic hydrocarbon solvent.

[0106] Examples of aromatic hydrocarbon solvents include benzene, toluene, ethylbenzene, propylbenzene, butylbenzene, xylene, chlorobenzene, and dichlorobenzene. Examples of non-aromatic hydrocarbon solvents include n-alkanes such as n-pentane and n-hexane, and cycloalkanes such as cyclohexane and methylcyclohexane.

[0107] Examples of oxygen-containing organic compounds include aliphatic carboxylic acids, aromatic carboxylic acids, and acid anhydrides thereof, with acetic acid, propionic acid, benzoic acid, phthalic acid, toluic acid, and acid anhydrides thereof being preferred. Specific examples of other oxygen-containing organic compounds include the compounds described in paragraphs

[0041] and

[0042] of WO 2010 / 055652.

[0108] <Other cocatalysts> The olefin polymerization catalyst may further contain at least one other promoter selected from organometallic compounds (B-1) and compounds (B-2) that react with transition metal compounds to form ion pairs.

[0109] Examples of the organometallic compound (B-1) include organoaluminum compounds represented by the general formula (B-1a), organoaluminum compounds such as alkyl complexes of Group 1 metals and aluminum represented by the general formula (B-1b), and dialkyl compounds of Group 2 or Group 12 metals represented by the general formula (B-1c).

[0110] (B-1a):R a m Al(OR b ) n Hp X q In formula (B-1a), R a and R b are each independently a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, X is a halogen atom, m satisfies 0 < m ≦ 3, n satisfies 0 ≦ n < 3, p satisfies 0 ≦ p < 3, q satisfies 0 ≦ q < 3, and m + n + p + q = 3. The hydrocarbon group is, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0111] Examples of the organoaluminum compound (B-1a) include tri(n-alkyl)aluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, tri(n-butyl)aluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, etc.; trialkylaluminums of tri-branched-chain alkylaluminums such as triisopropylaluminum, triisobutylaluminum, tri(sec-butyl)aluminum, tri(tert-butyl)aluminum, tri(2-methylbutyl)aluminum, tri(3-methylbutyl)aluminum, tri(2-methylpentyl)aluminum, tri(3-methylpentyl)aluminum, tri(4-methylpentyl)aluminum, tri(2-methylhexyl)aluminum, tri(3-methylhexyl)aluminum, tri(2-ethylhexyl)aluminum, etc.; dialkylaluminum hydrides such as diisobutylaluminum hydride; tricycloalkylaluminums such as tricyclohexylaluminum, tricyclooctylaluminum; and triarylaluminums such as triphenylaluminum, tritolylaluminum. [[ID=##]] [[ID=##]]

[0112] [[ID=##]] (B-1b): M 2 AlR a 4 In formula (B-1b), M 2 is Li, Na or K, and R ais a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 5 carbon atoms. Examples of the alkylated complex (B-1b) include LiAl(C2H5)4, LiAl(C7H 15 )4 can be mentioned.

[0113] (B-1c):R a R b M 3 In formula (B-1c), R a and R b are each independently a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 5 carbon atoms, and M 3 is Mg, Zn or Cd. Examples of the compound (B-1c) include dimethyl magnesium, diethyl magnesium, di-n-butyl magnesium, ethyl-n-butyl magnesium, diphenyl magnesium, dimethyl zinc, diethyl zinc, di-n-butyl zinc and diphenyl zinc.

[0114] Examples of the compound (B-2) that reacts with a transition metal compound to form an ion pair include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in, for example, JP-T-1-501950, JP-T-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, and U.S. Pat. No. 5,321,106. Further examples include heteropoly compounds and isopoly compounds.

[0115] <Amount of each ingredient used> When olefins are polymerized using an olefin polymerization catalyst, the amounts of each component that can constitute the olefin polymerization catalyst are as follows: In addition, the contents of each component in the olefin polymerization catalyst can be set as follows:

[0116] Transition metal compounds are typically used in amounts of 1 x 10 per liter of reaction volume used in olefin polymerization. -10 ~1×10 -2 mol, preferably 1 x 10 -8 ~1×10 -3It is used in molar amounts.

[0117] The solid aluminoxane can be used in an amount such that the molar ratio (Al / M) of aluminum atoms in the solid aluminoxane to all transition metal atoms (M) in the transition metal compound is usually 10 to 5,000, and preferably 20 to 2,000.

[0118] The organometallic compound (B-1) can be used in an amount such that the molar ratio ((B-1) / M) of the compound (B-1) to the total transition metal atoms (M) in the transition metal compound is usually 1 to 50,000, preferably 10 to 20,000.

[0119] The compound (B-2), which reacts with the transition metal compound to form an ion pair, can be used in an amount such that the molar ratio ((B-2) / M) of the compound (B-2) to the total transition metal atoms (M) in the transition metal compound is usually 1 to 1000, preferably 1 to 200.

[0120] The olefin polymerization catalyst is prepared by incorporating a transition metal compound, a solid aluminoxane, and, if necessary, other cocatalysts into the polymerization catalyst. For example, the catalyst can be obtained by bringing the transition metal compound, the solid aluminoxane, and, if necessary, other cocatalysts, etc., into contact with each other.

[0121] The order of addition and contact of the components constituting the olefin polymerization catalyst can be selected arbitrarily, but examples include the following method: Hereinafter, the transition metal compound will also be referred to as "component (A)," the solid aluminoxane as "support," and the other co-catalyst as "component (B)." A method in which component (A) and the carrier are added to a polymerization reactor. A method in which component (A), component (B) and the carrier are each added to a polymerization reactor. A method in which a supported catalyst in which component (A) is supported on a carrier is added to a polymerization reactor. A method in which a supported catalyst in which component (A) is supported on a carrier and component (B) are added to a polymerization reactor. A method in which a supported catalyst in which component (A) and component (B) are supported on a carrier are added to a polymerization reactor.

[0122] In the above-mentioned method, the order of addition and contact is not particularly limited. Furthermore, each component constituting the olefin polymerization catalyst may be added and contacted in a state of being dissolved or dispersed in the above-mentioned inert hydrocarbon medium.

[0123] In the above-mentioned carrier or supported catalyst, an olefin may be prepolymerized, or a catalyst component may be further supported on the prepolymerized solid catalyst component. Examples of the olefin include the above-mentioned α-olefins such as 4-methyl-1-pentene and 3-methyl-1-pentene.

[0124] <Production conditions of olefin polymer> Preferred production conditions for the olefin polymer to be deashed are described below. The polymerization can be carried out by either a slurry polymerization method or a gas phase polymerization method, with the slurry polymerization method being preferred. Examples of inert hydrocarbon media used in slurry polymerization include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane. The inert hydrocarbon medium may be used alone or in combination of two or more. Alternatively, a so-called bulk polymerization method may be used in which the liquefied olefin to be supplied to the polymerization itself is used as the solvent.

[0125] The polymerization temperature of the olefin is usually -50 to +200°C, preferably 0 to 180°C; the polymerization pressure is usually normal pressure to 10 MPa gauge pressure, preferably normal pressure to 5 MPa gauge pressure. The polymerization reaction can be carried out by any of batch, semi-continuous, and continuous methods. Furthermore, the polymerization can be carried out in two or more stages with different reaction conditions.

[0126] Hydrogen is a preferred additive because it can improve the polymerization activity of the catalyst and increase or decrease the molecular weight of the polymer. When hydrogen is added to the system, the appropriate amount is about 0.00001 to 100 NL per mole of olefin.

[0127] [Method of producing purified olefin polymer] A preferred method for producing a purified olefin polymer of the present invention is A step of preparing a crude olefin polymer containing an aluminum compound in an amount exceeding 4.0 ppm by mass in terms of aluminum atoms and having a melting point and / or glass transition temperature of 110°C or higher; a step of purifying the crude olefin polymer by the above-mentioned method for purifying an olefin polymer of the present invention to produce a purified olefin polymer having an aluminum content of 3.0 mass ppm or less in terms of aluminum atoms. The present invention is characterized in that it includes:

[0128] The crude olefin polymer may be the olefin polymer composition described above. The lower limit of the aluminum compound content in the crude olefin polymer is preferably 10 ppm by mass, more preferably 100 ppm by mass, even more preferably 1000 ppm by mass, and particularly preferably 5000 ppm by mass, calculated as aluminum atoms, while the upper limit is preferably 100,000 ppm by mass, more preferably 50,000 ppm by mass, even more preferably 20,000 ppm by mass, and particularly preferably 10,000 ppm by mass.

[0129] The upper limit of the aluminum content in terms of aluminum atoms in the purified olefin polymer is preferably 2.5 ppm by mass, more preferably 2.0 ppm by mass, still more preferably 1.5 ppm by mass, and particularly preferably 1.0 ppm by mass. The lower limit is, of course, preferably 0 ppm by mass. When the aluminum content in terms of aluminum atoms of the purified olefin polymer falls within the above range, the polymer has excellent electrical insulation properties and can be suitably used for a variety of electrical materials.

[0130] [Application] The olefin polymer purified by the purification method of the present invention and the purified olefin polymer obtained by the production method of the present invention can be processed into desired molded articles, for example, films, sheets, sealants, blow molded articles, injection stretch blow molded articles, injection molded articles, fibers, etc., by various molding methods such as injection molding, extrusion molding, injection stretch blow molding, blow molding, and cast molding.

[0131] In this case, the olefin polymer or the purified olefin polymer may be blended with various additives, such as antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, inorganic or organic fillers, and various synthetic resins, as needed.

[0132] The olefin polymer purified by the purification method of the present invention and the purified olefin polymer obtained by the production method of the present invention have a reduced amount of aluminum, and are therefore suitable for applications in which electrical properties are important. [Example]

[0133] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. The methods for measuring physical properties are as follows.

[0134] [Elemental analysis] Measurements were carried out using an ICPS-8100 ICP (inductively coupled plasma) optical emission spectrometry device manufactured by Shimadzu Corporation. For quantitative analysis of aluminum, the sample was wet decomposed with sulfuric acid and nitric acid, and the resulting solution was reduced to a fixed volume (filtered and diluted as necessary) to prepare the test solution. (Qualitative and quantitative analysis of transition metals such as zirconium can also be carried out using the same method, if necessary.)

[0135] [Synthesis Example 1] [Synthesis of Transition Metal Complexes] 8-Octamethylfluoren-12'-yl-(2-(adamantan-1-yl)-8-methyl-3,3b,4,5,6,7,7a,8-octahydrocyclopenta[a]indene)zirconium dichloride represented by the following formula was synthesized according to the method described in Preliminary Experiment 5 of WO 2014 / 123212.

[0136] [ka]

[0137] [Manufacturing Example 1] [Production of Olefin Polymer] (Production of olefin polymerization catalysts) At 30°C, a 100 L pressure-resistant reactor equipped with a stirrer and thoroughly purged with nitrogen was charged with 36 L of purified decane and 16.7 mol of solid polymethylaluminoxane (hereinafter also referred to as "solid MAO") in terms of aluminum atoms under a nitrogen stream to form a suspension. To this suspension, 57 g (66.8 mmol) of the transition metal compound (8-octamethylfluoren-12'-yl-(2-(adamantan-1-yl)-8-methyl-3,3b,4,5,6,7,7a,8-octahydrocyclopenta[a]indene))zirconium dichloride) prepared in Synthesis Example 1 was added as a 26.7 mmol / L toluene solution with stirring. After 1.5 hours, stirring was stopped, the mixture was allowed to stand, and the supernatant was removed and washed three times with 44 L of decane to obtain an olefin polymerization catalyst slurry.

[0138] (Preparation of Prepolymerized Catalyst Component) To the slurry of the olefin polymerization catalyst, 1580 mL of a hexane solution of tri-normal octylaluminum (0.37 mol / mL in terms of aluminum atom) and 10.2 L of 4-methyl-1-pentene were added while stirring the slurry. After 4 hours, stirring was stopped, and the resulting mixture was allowed to stand for separation. The supernatant was removed and washed three times with 44 L of decane to obtain a decane slurry of a prepolymerization catalyst component (1.03 mmol-Zr / L).

[0139] (Production of olefin polymers) At room temperature under a nitrogen stream, 3500 L of purified decane and a hexane solution of tri-normal octylaluminum (2800 mmol in terms of aluminum atoms) were charged into an 8260 L pressure-resistant reactor equipped with a stirrer (hereinafter sometimes referred to as a polymerization vessel). Next, 9 mmol of the prepolymerized catalyst component slurry in decane (in terms of zirconium atoms) was added, and 105 L of hydrogen was added to the polymerization vessel. Next, 663 kg of 4-methyl-1-pentene and 29.2 kg of a mixture of 1-hexadecene and 1-octadecene (commercially available) were continuously charged into the polymerization vessel at a constant rate over 53 minutes. The start of the charging marked the start of polymerization. The temperature was raised to 45°C over 15 minutes after the start of polymerization and then maintained at 45°C for 2 hours. Two hours after the start of polymerization, the polymerization vessel was pressurized and depressurized five times from 0.5 MPaG to 0.05 MPaG using nitrogen. Hydrogen was then added to the 28-L polymerization vessel, and 253 kg of 4-methyl-1-pentene and 206.3 kg of the above-mentioned mixture of 1-hexadecene and 1-octadecene (commercially available) were continuously charged into the polymerization vessel at a constant rate over 33 minutes and maintained for 4 hours. After 4 hours, 5.6 kg of acetylacetone was added as a deactivator to terminate the polymerization, yielding a slurry of 4-methyl-1-pentene polymer having a melting point of 190°C or higher.

[0140] [Example 1] [Purification of Olefin Polymer] (First demineralization process) The entire amount of the 4-methyl-1-pentene polymer slurry obtained in Production Example 1 was transferred to a filter dryer with an internal volume of 9000 L, and 20 kg of acetylacetone was added as a demineralizing agent. The mixture was then heated to 60°C and stirred for 8 hours to carry out a demineralizing operation. After 8 hours, the mixture was filtered to obtain a wet cake.

[0141] (Second demineralization process) A 10 g sample of the wet cake obtained by the above procedure was dried in a small heated vacuum dryer at 110°C for 6 hours, and the amount of aluminum remaining in the dried product was analyzed. The results are shown in Table 1.

[0142] [Comparative Examples 1 and 2, Examples 2 and 3] A dried product was obtained by the same procedure as in the second demineralization step of Example 1, except that the holding temperature and holding time were changed as shown in Table 1. The amount of aluminum remaining in the obtained dried product was analyzed. The results are shown in Table 1.

[0143] [Table 1]

[0144] Even though the holding temperature in the second demineralization step was lower than the sublimation temperature (170 to 180°C) of aluminum acetylacetonato complex (Al(acac)3), the amount of aluminum in the polymer was reduced.

Claims

1. a first step of contacting, under an inert gas atmosphere, an olefin polymer composition containing an olefin polymer having a melting point and / or glass transition temperature of 110°C or higher, a transition metal compound containing a metal element selected from elements of Groups 3 to 11 of the periodic table, and an organometallic compound containing a metal element selected from elements of Groups 1, 2, and 13 of the periodic table, with at least one compound selected from the group consisting of acetylacetone, acetylacetone derivatives, and 2'-hydroxyacetophenone to obtain a contact product; a second step of maintaining the contact product in an inert gas atmosphere at a temperature of 100° C. or higher and not higher than the melting point of the olefin polymer for 0.1 to 100 hours; A method for purifying an olefin polymer having the formula:

2. 2. The method for purifying an olefin polymer according to claim 1, wherein the olefin polymer is a polymer of at least one olefin selected from ethylene and an α-olefin having 3 to 20 carbon atoms.

3. 3. The method for purifying an olefin polymer according to claim 1, wherein the olefin polymer has a structural unit derived from 4-methyl-1-pentene.

4. 4. The method for purifying an olefin polymer according to claim 1, wherein the transition metal compound is a metallocene compound.

5. 5. The method for purifying an olefin polymer according to claim 1, wherein the organometallic compound is a solid aluminoxane.

6. 6. The method for purifying an olefin polymer according to claim 5, wherein the solid aluminoxane is solid polymethylaluminoxane.

7. The method for purifying an olefin polymer according to any one of claims 1 to 6, wherein the olefin polymer composition contains an olefin polymer produced using an olefin polymerization catalyst in which a transition metal compound is supported on a solid aluminoxane.

8. A method for purifying an olefin polymer according to any one of claims 1 to 7, wherein in the first step, the olefin polymer composition is contacted with at least one compound selected from the group consisting of acetylacetone, acetylacetone derivatives, and 2'-hydroxyacetophenone in a slurry state, and then a solid-liquid separation step is carried out to obtain the contact product.

9. preparing a crude olefin polymer containing an aluminum compound in an amount exceeding 4.0 ppm by mass in terms of aluminum atoms and having a melting point and / or glass transition temperature of 110°C or higher; A step of purifying the crude olefin polymer by the method for purifying an olefin polymer according to any one of claims 1 to 8, to produce a purified olefin polymer having an aluminum content of 3.0 mass ppm or less in terms of aluminum atoms. A method for producing a purified olefin polymer, comprising:

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