JP7131930B2 - Method for producing olefin polymer - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can produce an olefin polymer with high activity, effectively prevent contamination of the inside of the polymerization vessel such as the walls of the polymerization vessel and stirring blades, and can stably operate for a long period of time. The present invention relates to a method for producing an olefin polymer.

Conventionally, there are various methods such as liquid phase polymerization and gas phase polymerization as methods for polymerizing olefin monomers. For example, in gas phase polymerization, a polymer is obtained in the form of powder, and in liquid phase polymerization, the polymer is often recovered as powder because of ease of handling. And a closed space where the polymer powder exists, for example, a polymerization reactor and each pipe for producing polymer powder in gas phase polymerization, a storehouse for storing polymer powder obtained by gas phase polymerization or liquid phase polymerization, etc. It is required to be excellent in fluidity.

By the way, polyolefins such as polyethylene, polypropylene, ethylene/α-olefin copolymers, and propylene/α-olefin copolymers are heated in the presence of solid catalysts such as solid titanium-based catalysts and carrier-supported metallocene-based catalysts. It is produced by polymerizing olefins. This solid catalyst often has low fluidity and can be difficult to feed into a polymerization reactor.

In addition, when olefin is polymerized in the gas phase in the presence of a solid catalyst, polymer lumps or sheet-like materials are generated in the fluidized bed, or the fluidity of the olefin polymer is reduced, resulting in a mixed state in the fluidized bed. becomes non-uniform, causing problems such as inability to operate stably for a long period of time.

In addition, the piping attached to the polymerization reactor, the piping connecting each stage of the gas phase polymerization using a fluidized bed reactor in multiple stages, and other various equipment for moving polymer powder etc. , when the solid catalyst or polymer powder moves, the fluidity is reduced, and in places where the fluidity is reduced in various equipment, so-called dead space, polymer lumps are generated or adhere to the sheet material. As a result, the flowability of the polymer powder is lowered, and in the worst case, a problem may arise that the pipes or the like are clogged. In addition, when the finally obtained polymer powder is collected or stored in a storage box, etc., the flowability of the polymer powder is lowered, so that the polymer powders are bound to each other and stored in the storage box. There may also be a problem that various subsequent processes are delayed, such as a bridge being generated within.

On the other hand, in Patent Document 1, by continuously adding a compound having a specific structure among phenolic antioxidants or phosphorus antioxidants and having a melting point of 70° C. or less to a polymerization vessel, heat is applied to the polymer. It is described that a stabilizing effect and an effect of suppressing foaming during molding can be imparted.

WO2015/060257

The present inventors considered that the effect of suppressing fouling in the method of Patent Document 1 described above is unknown, and that there is room for improvement in terms of polymerization activity. That is, the object of the present invention is to produce an olefin polymer with high activity, to effectively prevent contamination of the inside of the polymerization vessel such as the walls and stirring blades of the polymerization vessel, and to operate stably for a long period of time. An object of the present invention is to provide a method for producing an olefin polymer capable of

The present inventors have made intensive studies to solve the above problems, and as a result, found that the use of a specific amount of a specific phosphite compound is very effective in improving polymerization activity and suppressing fouling. I have perfected my invention. That is, the gist of the present invention is as follows.

[1] Solid catalyst component for olefin polymerization (A), and
In the presence of a phosphite compound (B) represented by the following general formula (I),
A method for producing an olefin polymer by (co)polymerizing one or more olefins selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms in a polymerization vessel,
A method for producing an olefin polymer, characterized in that the phosphite compound (B) is supplied in an amount of 0.1 ppm by mass or more and less than 50 ppm by mass relative to the yield of the olefin polymer.

(In Formula (I), R ¹ to R ⁵ are hydrogen atoms or hydrocarbon groups having 1 to 30 carbon atoms, and may be the same or different.)

[2] The method for producing an olefin polymer according to [1], wherein the olefin is ethylene alone or ethylene and an α-olefin having 3 to 20 carbon atoms.

[3] The method for producing an olefin polymer according to [1] or [1], wherein the olefin (co)polymerization is carried out in a suspension or in a gas phase.

[4] Component (A) is
(A-1) a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl skeleton;
(A-2) (a) an organometallic compound,
(b) an organoaluminumoxy compound, and
(c) a compound that forms an ion pair by reacting with (A-1)
At least one compound selected from
(A-3) The method for producing an olefin polymer according to any one of [1] to [3], including a particulate carrier.

The phosphite compound (B) used in the present invention can suppress adhesion of the polymer to the inside of the polymerization vessel even when added in a relatively small amount, and the decrease in polymerization activity is small. Therefore, according to the present invention, it is possible to produce an olefin polymer with high activity, effectively prevent contamination of the inside of the polymerization vessel such as the walls of the polymerization vessel and the stirring blades, and operate stably for a long period of time. be able to.

[Solid catalyst component for olefin polymerization (A)]
The solid catalyst component (A) for olefin polymerization used in the present invention is preferably a solid catalyst component containing a transition metal compound selected from Groups 3 to 12 of the periodic table. Specific examples thereof include a carrier-supported transition metal complex-based catalyst component in which a transition metal compound of groups 4 to 6 of the periodic table is supported on a particulate carrier, and a solid titanium catalyst component and an organoaluminum compound. Examples include titanium-based catalyst components and Phillips catalyst components in which any chromium compound that can be oxidized to chromium trioxide is supported on an inorganic oxide solid such as silica.

Among them, a carrier-supported metallocene-based catalyst component belonging to the carrier-supported transition metal complex-based catalyst component is preferable, and a carrier-supported metallocene-based catalyst component containing the following components (A-1) to (A-3): is more preferred.
(A-1) a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl skeleton;
(A-2) (a) an organometallic compound,
(b) an organoaluminumoxy compound, and
(c) a compound that forms an ion pair by reacting with (A-1)
At least one compound selected from
(A-3) Particulate carrier

The periodic table groups 4 to 6 transition metal compound used in the carrier-supported transition metal complex-based catalyst component may be any known periodic table group 4 to 6 transition metal compound having olefin polymerization ability. Groups 4-6 transition metal halides, transition metal alkylates, transition metal alkoxylates, non-bridged or bridged metallocene compounds can be used. In particular, transition metal compounds of Group 4 of the periodic table are preferred. Specific examples include titanium tetrachloride, dimethyltitanium dichloride, tetrabenzyltitanium, tetrabenzylzirconium, and tetrabutoxytitanium. Furthermore, non-crosslinkable or crosslinkable metallocene compounds are particularly preferred from the viewpoint of polymerization activity and the like. A metallocene compound is a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl skeleton, and is represented, for example, by the following general formula (II).

ML _X (II)

(In formula (II), M is a transition metal of Group 4 of the periodic table (specifically, zirconium, titanium or hafnium), L is a ligand (group) that coordinates to the transition metal, and at least one L is a ligand having a cyclopentadienyl skeleton, L other than the ligand having a cyclopentadienyl skeleton is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a halogen an atom, a trialkylsilyl group, —SO ₃ R (R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen) or a hydrogen atom, and x is the valence of the transition metal; is the number of L.)

Specific examples of ligands having a cyclopentadienyl skeleton include a cyclopentadienyl group; a methylcyclopentadienyl group, a dimethylcyclopentadienyl group, a trimethylcyclopentadienyl group, and a tetramethylcyclopentadienyl group. , pentamethylcyclopentadienyl group, ethylcyclopentadienyl group, methylethylcyclopentadienyl group, propylcyclopentadienyl group, methylpropylcyclopentadienyl group, butylcyclopentadienyl group, methylbutylcyclopenta dienyl group, alkyl-substituted cyclopentadienyl group such as hexylcyclopentadienyl group; indenyl group; 4,5,6,7-tetrahydroindenyl group; and fluorenyl group. These groups may have substituents such as halogen atoms and trialkylsilyl groups.

As a ligand having a cyclopentadienyl skeleton, an alkyl-substituted cyclopentadienyl group is particularly preferred. When the compound represented by the general formula (II) contains two or more groups having a cyclopentadienyl skeleton, two of the groups having a cyclopentadienyl skeleton are alkylene groups such as ethylene and propylene; They may be bonded via an alkylidene group such as ridene and diphenylmethylene; a silylene group; a substituted silylene group such as a dimethylsilylene group, a diphenylsilylene group and a methylphenylsilylene group. Also, two or more groups having cyclopentadienyl skeletons are preferably the same.

Specific examples of hydrocarbon groups having 1 to 12 carbon atoms which are ligands other than ligands having a cyclopentadienyl skeleton include methyl, ethyl, propyl, isopropyl, butyl and pentyl. cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group and tolyl group; and aralkyl groups such as benzyl group and neophyll group. Specific examples of alkoxy groups include methoxy, ethoxy and butoxy groups. A specific example of the aryloxy group is a phenoxy group. Specific examples of halogen atoms include fluorine, chlorine, bromine and iodine. Specific examples of —SO ₃ R include a p-toluenesulfonato group, a methanesulfonato group, and a trifluoromethanesulfonato group.

For example, when the valence of the transition metal is 4, the compound represented by general formula (II) is more specifically represented by general formula (II') below.

MR ^a R ^b R ^c R ^d (II′)

(In formula (II′), M is zirconium, titanium or hafnium, R ^a is a group having a cyclopentadienyl skeleton, R ^b , R ^c and R ^d may be the same or different, A group having a cyclopentadienyl skeleton, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group, —SO ₃ R (where R has a substituent such as halogen). optionally a hydrocarbon group having 1 to 8 carbon atoms) or a hydrogen atom).

Particularly preferred as component (A-1) is a transition metal compound in which one of R ^b , R ^c and R ^d in general formula (II′) is a group having a cyclopentadienyl skeleton. For example, when R ^a and R ^b are groups having a cyclopentadienyl skeleton, these groups having a cyclopentadienyl skeleton are alkylene, substituted alkylene, alkylidene, silylene, substituted silylene, etc. may be combined. R ^c and R ^d in this case are an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group, —SO ₃ R, or a hydrogen atom.

Specific examples of transition metal compounds in which M is zirconium are shown below. Bis(indenyl)zirconium dichloride, bis(indenyl)zirconium dibromide, bis(indenyl)zirconium bis(p-toluenesulfonato), bis(4,5,6,7-tetrahydroindenyl)zirconium dichloride, bis(fluorenyl) Zirconium dichloride, ethylenebis(indenyl)zirconium dichloride, ethylenebis(indenyl)zirconium dibromide, ethylenebis(indenyl)dimethylzirconium, ethylenebis(indenyl)diphenylzirconium, ethylenebis(indenyl)methylzirconium monochloride, ethylenebis(indenyl) ) zirconium bis(methanesulfonato), ethylenebis(indenyl)zirconium bis(p-toluenesulfonato), ethylenebis(indenyl)zirconium bis(trifluoromethanesulfonato), ethylenebis(4,5,6,7-tetrahydro indenyl)zirconium dichloride, isopropylidene(cyclopentadienyl-fluorenyl)zirconium dichloride, isopropylidene(cyclopentadienyl-methylcyclopentadienyl)zirconium dichloride, dimethylsilylenebis(cyclopentadienyl)zirconium dichloride, dimethylsilylene Bis(methylcyclopentadienyl)zirconium dichloride, dimethylsilylenebis(dimethylcyclopentadienyl)zirconium dichloride, dimethylsilylenebis(trimethylcyclopentadienyl)zirconium dichloride, dimethylsilylenebis(indenyl)zirconium dichloride, dimethylsilylenebis( indenyl)zirconium bis(trifluoromethanesulfonato), rac-dimethylsilylenebis{1-(2-methyl-4,5-acenaphthocyclopentadienyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2- methyl-4,5-benzoindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methyl-4-isopropyl-7-methylindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-( 2-methyl-4-phenylindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methylindenyl)}zirconium dichloride, dimethylsilylenebis(4,5,6,7-tetrahydroindenyl)zirconium Zik chloride, dimethylsilylene(cyclopentadienyl-fluorenyl)zirconium dichloride, diphenylsilylenebis(indenyl)zirconium dichloride, methylphenylsilylenebis(indenyl)zirconium dichloride, bis(cyclopentadienyl)zirconium dichloride, bis(cyclopentadienyl) ) zirconium dibromide, bis(cyclopentadienyl)methylzirconium monochloride, bis(cyclopentadienyl)ethylzirconium monochloride, bis(cyclopentadienyl)cyclohexylzirconium monochloride, bis(cyclopentadienyl)phenylzirconium monochloride, bis(cyclopentadienyl)benzylzirconium monochloride, bis(cyclopentadienyl)zirconium monochloride monohydride, bis(cyclopentadienyl)methylzirconium monohydride, bis(cyclopentadienyl)dimethylzirconium, Bis(cyclopentadienyl)diphenylzirconium, bis(cyclopentadienyl)dibenzylzirconium, bis(cyclopentadienyl)zirconium methoxychloride, bis(cyclopentadienyl)zirconium ethoxychloride, bis(cyclopentadienyl) Zirconium bis(methanesulfonato), bis(cyclopentadienyl)zirconium bis(p-toluenesulfonato), bis(cyclopentadienyl)zirconium bis(trifluoromethanesulfonato), bis(methylcyclopentadienyl)zirconium Dichloride, bis(dimethylcyclopentadienyl)zirconium dichloride, bis(dimethylcyclopentadienyl)zirconium ethoxychloride, bis(dimethylcyclopentadienyl)zirconium bis(trifluoromethanesulfonato), bis(ethylcyclopentadienyl) Zirconium dichloride, bis(methylethylcyclopentadienyl)zirconium dichloride, bis(propylcyclopentadienyl)zirconium dichloride, bis(methylpropylcyclopentadienyl)zirconium dichloride, bis(butylcyclopentadienyl)zirconium dichloride, bis (methylbutylcyclopentadienyl)zirconium dichloride, bis(methylbutylcyclopentadienyl)zirconium bis(methanesulfonato), bis(trimethylcyclopentadienyl) ) zirconium dichloride, bis(tetramethylcyclopentadienyl)zirconium dichloride, bis(pentamethylcyclopentadienyl)zirconium dichloride, bis(hexylcyclopentadienyl)zirconium dichloride, bis(trimethylsilylcyclopentadienyl)zirconium dichloride, etc. .

In each of the above examples, disubstituted cyclopentadienyl ring includes 1,2- and 1,3-substituted, and trisubstituted includes 1,2,3- and 1,2,4-substituted. include. Alkyl groups such as propyl and butyl include isomers such as n-, i-, sec- and tert-.

In addition, in each of the above zirconium compounds, transition metal compounds in which zirconium metal is substituted with titanium metal or hafnium metal can also be used. In addition to titanium compounds and hafnium compounds having a similar steric structure, bromides, iodides, etc., for example, JP-A-3-9913, JP-A-2-131488, JP-A-3-21607, JP-A-3-21607, JP-A-3-21607, JP-A-3-106907, JP-A-3-188092, JP-A-4-69394, JP-A-4-300887, International Publication No. 2001/27124, etc. Transition metal compounds such as those described in can be mentioned.

Examples of transition metal compounds include transition metal compounds represented by the following general formula (III) as described in JP-A-11-315109.

(In formula (III), M represents a transition metal atom of groups 4 to 6 of the periodic table, m represents an integer of 1 to 6, R ¹¹ to R ¹⁶ may be the same or different, and hydrogen represents an atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group; , two or more of these may be linked together to form a ring, and when m is 2 or more, two groups out of R ¹¹ to R ¹⁶ may be linked ( However, R ¹¹ is not bonded to each other), n is a number that satisfies the valence of M, and X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, boron containing group, aluminum-containing group, phosphorus-containing group, halogen-containing group, heterocyclic compound residue, silicon-containing group, germanium-containing group, or tin-containing group; The groups may be the same or different, and multiple groups represented by X may be combined to form a ring.)

The component (A-2) constituting the carrier-supported transition metal complex-based catalyst component reacts with the organometallic compound (a), the organoaluminum oxy compound (b), and (A-1) to form an ion pair. is at least one compound selected from the compounds (c) that

As the organometallic compound (a), for example, organometallic compounds of Groups 1 and 2 and Groups 12 and 13 of the periodic table represented by the following general formulas (IV), (V), and (VI) can be used. .

^RemAl _{( ORf )} ^nHpXq ( _IV )
(In formula (IV), R ^e and R ^f may be the same or different, and represent a hydrocarbon group having 1 to 15, preferably 1 to 4 carbon atoms, X represents a halogen atom, m is 0<m≦3, n is 0≦n<3, p is 0≦p<3, q is a number of 0≦q<3, and m+n+p+q=3.)

Organoaluminum compound represented by. Specific examples of this compound include trimethylaluminum, triethylaluminum, triisobutylaluminum, and diisobutylaluminum hydride.

M ² AlR ^g ₄ (V)
(In formula (V), ^M2 represents Li, Na or K, and ^Rg represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms.)

A complex alkylate of a Group 1 metal of the periodic table represented by and aluminum. Specific examples of this compound include LiAl(C ₂ H ₅ ) ₄ and LiAl(C ₇ H ₁₅ ) ₄ .

R ^h R ⁱ M ³ (VI)
(In formula (VI), R ^h and R ⁱ may be the same or different and represent a hydrocarbon group having 1 to 15, preferably 1 to 4 carbon atoms; M ³ is Mg, Zn or Cd; is.)
A dialkyl compound of a metal of Group 2 or Group 12 of the periodic table represented by

Among the above organometallic compounds, organoaluminum compounds are preferred. Moreover, an organic metal compound may be used individually by 1 type, and may be used in combination of 2 or more types.

A known aluminoxane can be used as the organoaluminumoxy compound (b). Specifically, for example, compounds represented by the following general formulas (VII) and (VIII) can be used.

(In formulas (VII) and (VIII), R ²¹ to R ²⁴ are hydrocarbon groups having 1 to 10 carbon atoms, and n is an integer of 2 or more.)

As the organoaluminumoxy compound (b), a methylaluminoxane in which R is a methyl group and n is 3 or more, preferably 10 or more in the above general formulas (VII) and (VIII) is preferably used. These aluminoxanes may be mixed with a small amount of organoaluminum compounds. It may also be a benzene-insoluble organoaluminumoxy compound as exemplified in JP-A-2-78687. Organic aluminum oxy compounds described in JP-A-2-167305, and aluminoxanes having two or more types of alkyl groups described in JP-A-2-24701 and JP-A-3-103407 are also suitable. Available.

Such aluminoxanes can be produced, for example, by the following methods (1) to (3), and are usually obtained as a solution in a hydrocarbon solvent.

(1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, cerous chloride hydrate, etc. A method of adding an organoaluminum compound such as trialkylaluminum to the hydrocarbon medium suspension of (1) to react the organoaluminum compound with the adsorbed water or water of crystallization.

(2) A method in which water, ice or steam is directly acted on an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether or tetrahydrofuran.

(3) A method of reacting an organoaluminum compound such as trialkylaluminum with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene or toluene.

Aluminoxanes may contain small amounts of organometallic components. Alternatively, the solvent or the unreacted organoaluminum compound may be removed by distillation from the recovered aluminoxane solution, and then dissolved again in the solvent.

Specific examples of organoaluminum compounds used in preparing aluminoxanes include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tri-tert- Trialkylaluminums such as butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum and tridecylaluminum; tricycloalkylaluminums such as tricyclohexylaluminum and tricyclooctylaluminum; dimethylaluminum chloride, diethylaluminum chloride and diethylaluminum bromide , diisobutylaluminum chloride and the like; dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride; dialkylaluminum alkoxides such as dimethylaluminum methoxide and diethylaluminum ethoxide; and dialkylaluminum aryloxides such as diethylaluminum phenoxide. be done. Among them, trialkylaluminum and tricycloalkylaluminum are preferred.

Furthermore, isoprenylaluminum represented by the following general formula (IX) can also be used as the organoaluminum compound.

(iC ₄ H ₉ ) _x Al _y (C ₅ H ₁₀ ) _z (IX)
(In formula (IX), x, y, and z are positive numbers, and z ≥ 2x)

An organic aluminum compound may be used individually by 1 type, and may be used in combination of 2 or more types.

Specific examples of solvents used in the preparation of aluminoxanes include aromatic hydrocarbons such as benzene, toluene, xylene, cumene and cymene; Hydrocarbons, alicyclic hydrocarbons such as cyclopentane, cyclohexane, cyclooctane and methylcyclopentane, petroleum fractions such as gasoline, kerosene and light oil, or the above aromatic hydrocarbons, aliphatic hydrocarbons and alicyclic hydrocarbons Hydrocarbon solvents such as halides, especially chlorides, bromides and the like are included. In addition, ethers such as ethyl ether and tetrahydrofuran can also be used. Among them, aromatic hydrocarbons are preferred.

Compound (c) (hereinafter referred to as "ionized ionic compound (c)") that reacts with (A-1) to form an ion pair includes, for example, JP-A-1-501950 and JP-A-1-502036. Publications, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, US Pat. Included are borane and carborane compounds, as well as heteropoly and isopoly compounds. The ionized ionic compound (c) may be used singly or in combination of two or more.

The organometallic compound (a), the organoaluminum oxy compound (b), and the ionized ionic compound (c), which are components that can be used as the component (A-2), have been described above. b) is preferably used as component (A-2).

Examples of the particulate carrier (A-3) include SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ and mixtures containing these (e.g. inorganic metal oxide carriers such as SiO ₂ —MgO, SiO ₂ —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); inorganic chloride carriers such as MgCl ₂ , MgBr ₂ , MnCl ₂ and MnBr ₂ ; and organic carriers such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and styrene-divinylbenzene copolymers. . In addition, clay, clay minerals that are components thereof, ion-exchangeable layered compounds, and the like can also be used as inorganic carriers.

The average particle size of the carrier using the inorganic compound is preferably 1-300 μm, more preferably 3-200 μm. Such a carrier is calcined at 100 to 1000° C., preferably 150 to 700° C., if necessary, before use.

The inorganic chloride may be used as it is, or may be used after pulverizing with a ball mill or vibration mill. Moreover, after dissolving an inorganic chloride in a solvent such as alcohol, it is also possible to use a product obtained by depositing fine particles using a precipitating agent.

Clay-based carriers are generally composed mainly of clay minerals. A carrier using an ion-exchangeable layered compound has a crystal structure in which planes formed by ionic bonds or the like are stacked in parallel with weak bonding force, and the ions contained therein can be exchanged. Most clay minerals are ion exchange layered compounds. Moreover, as these clays, clay minerals, and ion-exchangeable layered compounds, not only naturally occurring ones but also artificially synthesized ones can be used. In addition, clays, clay minerals, and ionic crystalline compounds having layered crystal structures such as hexagonal close-packing type, antimony type, _CdCl2 type, _CdI2 type, etc. are used as clays, clay minerals, or ion-exchangeable layered compounds. can be exemplified. Examples of such clays and clay minerals include kaolin, bentonite, kibushi clay, gyrome clay, allophane, hisingerite, pyrophyllite, ummo group, montmorillonite group, vermiculite, ryokudite group, palygorskite, kaolinite, nacrite, Dickite, halloysite and the like can be mentioned. Examples of the ion exchange layered compound include α-Zr(HAsO ₄ ) 2.H ₂ O, α-Zr(HPO ₄ ) ₂ , α-Zr(KPO ₄ ) _{2.3H 2} O, α _- Ti(HPO ₄ ) ₂ , α-Ti(HAsO ₄ ) 2.H ₂ O, α-Sn(HPO ₄ ) _{2.H 2 O} , γ-Zr(HPO ₄ ) ₂ , γ-Ti(HPO ₄ ) ₂ , γ _- Ti Crystalline acid salts of polyvalent metals such as (NH ₄ PO ₄ ) _{2.H 2 O} and the like can be mentioned. It is also preferable to chemically treat clay and clay minerals. Any chemical treatment can be used, such as a surface treatment for removing impurities adhering to the surface, a treatment for affecting the crystal structure of clay, or the like. Specific examples of chemical treatment include acid treatment, alkali treatment, salt treatment, organic substance treatment, and the like.

The ion-exchangeable layered compound may be a layered compound in which the interlayer spacing is expanded by exchanging the exchangeable ions between the layers with other large bulky ions by utilizing the ion-exchangeability. Such bulky ions play a pillar-like role supporting the layered structure and are usually called pillars. Also, the introduction of another substance between the layers of a layered compound is called intercalation. Guest compounds for intercalation include cationic inorganic compounds such as TiCl ₄ and ZrCl ₄ , metal alkoxides such as Ti(OR) ₄ , Zr(OR) ₄ , PO(OR) ₃ and B(OR) ₃ ( R is a hydrocarbon group, etc.), metal hydroxide ions such as [Al ₁₃ O ₄ (OH) ₂₄ ] ⁷⁺ , [Zr ₄ (OH) ₁₄ ] ²⁺ , [Fe ₃ O(OCOCH ₃ ) ₆ ] ⁺ mentioned. These compounds are used alone or in combination of two or more. Further, when intercalating these compounds, metal alkoxides such as Si(OR) ₄ , Al(OR) ₃ and Ge(OR) ₄ (R is a hydrocarbon group, etc.) are hydrolyzed to obtain Polymers, colloidal inorganic compounds such as SiO ₂ and the like can also coexist. Examples of pillars include oxides produced by intercalating the above metal hydroxide ions between layers and then dehydrating them by heating. Among these, preferred are clays or clay minerals, and particularly preferred are montmorillonite, vermiculite, pectolite, taeniolite and synthetic mica.

Organic compounds used as organic carriers include granular or particulate solids having a particle size in the range of 1 to 300 μm. Specifically, as exemplified above, α-olefins having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene are produced as main components (co-) Examples thereof include polymers or vinylcyclohexane, (co)polymers produced mainly from styrene, and modified products thereof.

In addition, by the method described in JP-A-11-140113, JP-A-2000-38410, JP-A-2000-95810, WO 2010/55652, etc., the component (A-2 ) can be used as the particulate carrier (A-3). In this case, the contact with the component (A-2) in the method for preparing a carrier-supported metallocene-based catalyst component described below is not essential.

A method for preparing a carrier-supported metallocene-based catalyst component, which is one of those preferably used as the solid catalyst component (A) for olefin polymerization, will be described. The carrier-supported metallocene-based catalyst component is a catalyst component in which a metallocene-based transition metal compound is supported on a carrier, and is preferably the above-described component (A-1) and component (A-2) [particularly preferably is a catalyst component comprising component (b)] and component (A-3). This carrier-supported metallocene catalyst can be prepared, for example, by mixing and contacting component (A-1), component (A-2) and component (A-3). The contact order of each component is arbitrary.

An inert hydrocarbon solvent is preferably used for the preparation of the carrier-supported metallocene-based catalyst component. Specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; benzene, toluene, Aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane; and mixtures thereof.

When preparing a carrier-supported metallocene-based catalyst component, the transition metal compound (A-1) is generally used in an amount of 0.001 to 1.0 mmol, preferably It is used in an amount of 0.005 to 0.5 mmol. The organoaluminumoxy compound (b) is generally used in an amount of 0.1 to 100 mmol, preferably 0.5 to 20 mmol in terms of aluminum atom. When an organoaluminum compound is used, the organoaluminum compound is generally used in an amount of 0.001 to 1000 mmol, preferably 2 to 500 mmol, per 1 g of the particulate carrier (A-3).

The temperature for mixing and contacting the above components is usually -50 to 150°C, preferably -20 to 120°C, and the contact time is 1 to 1000 minutes, preferably 5 to 600 minutes.

The carrier-supported metallocene-based catalyst component obtained in this way contains about 5×10 ⁻⁶ to 10 μg of the transition metal compound (A-1) in terms of transition metal atoms per 1 g of the particulate carrier (A-3). ⁻³ mol, preferably 10 ⁻⁵ to 3×10 ⁻⁴ mol, and the organoaluminum oxy compound (b) is about 10 ⁻³ to 10 ⁻¹ mol, preferably 2×10 ⁻¹ mol in terms of aluminum atom. It is desirable to be supported in an amount of ³ to 5×10 ⁻² mol.

The solid catalyst component for olefin polymerization (A) may be a prepolymerized catalyst component in which an olefin is prepolymerized. The prepolymerization catalyst component is composed of an olefin polymerization catalyst and, if necessary, an olefin polymer produced by prepolymerization. The prepolymerization catalyst contains a transition metal compound (A-1), a component (A-2) such as an organoaluminum oxy compound (b), and a particulate carrier (A-3), and is optionally prepolymerized. It contains an olefin polymer (D) produced by. As a method for preparing the prepolymerized catalyst, for example, a solid catalyst component obtained by mixing and contacting the components (A-1), (A-2) and (A-3) in an inert hydrocarbon solvent or an olefin medium. Another method is to prepolymerize a small amount of olefin. Specific examples of the inert hydrocarbon solvent used for preparing the prepolymerized catalyst include those similar to the inert hydrocarbon solvent used for preparing the carrier-supported metallocene catalyst described above.

The olefin used for prepolymerization is 100 to 0 mol% of ethylene, 0 to 49 mol% of propylene, and 0 to 100 mol% of olefin having 4 or more carbon atoms, preferably 100 to 0 mol% of ethylene. , 0 to 20 mol % propylene and 0 to 100 mol % olefin having 4 or more carbon atoms, more preferably 100 to 20 mol % ethylene, 0 to 20 mol % propylene and 4 carbon atoms It is desirable to contain 0 to 80 mol % of the above olefins, particularly preferably 100 to 20 mol % of ethylene and 0 to 80 mol % of olefins having 4 or more carbon atoms.

Specific examples of olefins having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, Examples include α-olefins having 4 to 20 carbon atoms such as 1-hexadecene, 1-octadecene and 1-eicosene. Furthermore, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a- Octahydronaphthalene, styrene, vinylcyclohexane, dienes and the like can also be used.

In preparing the prepolymerized catalyst, the transition metal compound (A-1) is generally used in an amount of 0.001 to 1.0 mmol, preferably 0.005 to 1.0 mmol, per 1 g of the particulate carrier (A-3) in terms of transition metal atom. It is used in an amount of 0.5 mmol. The organoaluminumoxy compound (b) is generally used in an amount of 0.1 to 100 mmol, preferably 0.5 to 20 mmol in terms of aluminum atom.

The prepolymerized catalyst obtained as described above contains about 5×10 ⁻⁶ to 10 ⁻³ moles of the transition metal compound (A-1) in terms of transition metal atoms per 1 g of the particulate carrier (A-3), It is preferably supported in an amount of 10 ⁻⁵ to 3×10 ⁻⁴ mol, and the organoaluminumoxy compound (b) is about 10 ⁻³ to 10 ⁻¹ mol, preferably 2×10 ⁻³ to 5×, in terms of aluminum atom. The olefin polymer (D) is supported in an amount of 10 ⁻² mol and produced by prepolymerization in an amount of about 0.1 to 500 g, preferably 0.3 to 300 g, particularly preferably 1 to 100 g. It is desirable to be

The solid catalyst component (A) for olefin polymerization can contain other components useful for polymerization in addition to the components described above. In addition, the carrier-supported metallocene-based catalyst component may optionally contain an organoaluminum compound or a surfactant during catalyst synthesis or prepolymerization, if necessary.

[Phosphite compound (B)]
The phosphite compound (B) used in the present invention is a compound represented by the following general formula (I).

(In Formula (I), R ¹ to R ⁵ are hydrogen atoms or hydrocarbon groups having 1 to 30 carbon atoms, and may be the same or different.)

R ¹ to R ⁵ in general formula (I) are hydrogen atoms or hydrocarbon groups having 1 to 30 carbon atoms, which may be aliphatic or aromatic, and may be linear, branched or cyclic. For example, both aliphatic hydrocarbon groups such as alkyl groups and alkenyl groups, and aromatic hydrocarbon groups can be used. Preferred specific examples are alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, lauryl group and oleoyl group, or alkenyl groups. groups. In addition, cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group and tolyl group; and aralkyl groups such as benzyl group and neophyll group. Among them, a hydrogen atom and an alkyl group having 1 to 20 carbon atoms are preferred.

Specific examples of the phosphite compound (B) represented by the general formula (I) include triphenylphosphite, tris(2-methylphenyl)phosphite, tris(2-tert-butylphenyl)phosphite, tris( 2-nonylphenyl)phosphite, tris(3-methylphenyl)phosphite, tris(3-tert-butylphenyl)phosphite, tris(3-nonylphenyl)phosphite, tris(4-methylphenyl)phosphite, tris(4-tert-butylphenyl)phosphite, tris(4-nonylphenyl)phosphite, tris(2,3-dimethylphenyl)phosphite, tris(2,4-dimethylphenyl)phosphite, tris(2, 5-dimethylphenyl)phosphite, tris(2,6-dimethylphenyl)phosphite, tris(3,4-dimethylphenyl)phosphite, tris(3,5-dimethylphenyl)phosphite, tris(2,4- di-tert-butylphenyl)phosphite, tris(2,3,4-trimethylphenyl)phosphite, tris(2,3,5-trimethylphenyl)phosphite, tris(2,3,6-trimethylphenyl)phosphite Phyto, Tris(2,4,5-trimethylphenyl)phosphite, Tris(2,4,6-trimethylphenyl)phosphite, Tris(3,4,5-trimethylphenyl)phosphite, Tris(2,3, 4,5-tetramethylphenyl)phosphite, tris(2,3,4,6-tetramethylphenyl)phosphite, tris(2,3,5,6-tetramethylphenyl)phosphite, tris(2,3 ,4,5,6-Pentamethylphenyl)phosphite. Among them, tris(4-nonylphenyl)phosphite, tris(4-tert-butylphenyl)phosphite and tris(2,4-di-tert-butylphenyl)phosphite are preferred.

[Production of olefin polymer]
In the method for producing an olefin polymer of the present invention, in the presence of the solid catalyst component for olefin polymerization (A) and the phosphite compound (B) described above, a group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms One or more olefins selected from are (co)polymerized in a polymerization vessel. In the present invention, the term "(co)polymerization" is used to include both polymerization and copolymerization. In the present invention, the terms "polymerization" and "polymer" may be used in the sense of including not only homopolymerization and homopolymerization but also copolymerization and copolymerization.

The method of adding the solid catalyst component (A) for olefin polymerization and the phosphite compound (B) during (co)polymerization is arbitrary, and component (B) may be added after component (A) is added. Alternatively, the component (A) may be added after the component (B) is added, or the component (A) and the component (B) may be mixed and contacted before the addition.

The polymerization can be carried out in suspension, solution or gas phase, and is preferably carried out in suspension or gas phase by slurry polymerization or gas phase polymerization. Specific examples of inert hydrocarbon media used in slurry polymerization include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, and methylcyclopentane. aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane, and mixtures thereof. Among them, aliphatic hydrocarbons and alicyclic hydrocarbons are preferred.

The polymerization temperature is generally −50 to 150° C., preferably 0 to 100° C. in the case of slurry polymerization, and generally 0 to 120° C., preferably 20 to 100° C. in the case of gas phase polymerization. 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 a batch system, a semi-continuous system and a continuous system.

It is also possible to divide the polymerization into two or more stages with different reaction conditions. The molecular weight of the resulting olefin polymer can also be adjusted by allowing hydrogen to exist in the polymerization system or by changing the polymerization temperature.

Specific examples of ethylene and α-olefins having 3 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene. These can be used singly or in combination of two or more. Further, in addition to ethylene and an α-olefin having 3 to 20 carbon atoms, other copolymerizable monomers may be used in combination for copolymerization. Examples of copolymerizable monomers include cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene may be mentioned. Furthermore, styrene, vinylcyclohexane, and dienes can also be used.

As the olefin, it is preferable to use ethylene alone or ethylene and an α-olefin having 3 to 20 carbon atoms. In particular, it is preferable to use 100 to 0 mol% of ethylene, 0 to 49 mol% of propylene, and 0 to 100 mol% of an olefin having 4 or more carbon atoms, and 100 to 0 mol% of ethylene and propylene. It is more preferable to use 0 to 20 mol% and 0 to 100 mol% of an α-olefin having 4 or more carbon atoms, 100 to 20 mol% of ethylene, 0 to 20 mol% of propylene, and the number of carbon atoms It is particularly preferable to use an α-olefin of 4 or more in the range of 0 to 80 mol%, and use ethylene in the range of 100 to 20 mol% and an α-olefin having 4 or more carbon atoms in the range of 0 to 80 mol%. is most preferred. Furthermore, in the present invention, it is preferable to produce an ethylene-based polymer containing ethylene as a main monomer. A (co)polymer containing an α-olefin component is preferred.

In the polymerization, the olefin polymerization catalyst (A) is generally used in an amount of 10 ⁻⁸ to 10 ⁻³ mol, preferably 10 ⁻⁷ to 10 −3 mol per liter of polymerization volume in terms of transition metal atoms in the transition metal compound (A-1). It is desirable to use an amount of 10 ^-4 mol. The organoaluminumoxy compound (A-2) can be used in an amount of usually 10 to 500 mol, preferably 20 to 200 mol, per 1 mol of the transition metal atom in the transition metal compound (A-1) in terms of aluminum atom. desirable.

The phosphite compound (B) is used in an amount of 0.1 ppm by mass or more and less than 50 ppm by mass relative to the olefin polymer yield. When the phosphite compound (B) is used in an amount of 0.1 ppm by mass or more, there is a tendency to sufficiently obtain the effect of suppressing the occurrence of various problems such as fouling. On the other hand, if it is used in an amount of less than 50 ppm by mass, it tends to be possible to suppress an increase in the load on recovery of the polymerization solvent and gas, an increase in the purification process, and a decrease in catalyst performance. In particular, since the phosphite compound (B) used in the present invention can effectively suppress the occurrence of various problems with a relatively small amount compared to conventional additives, the degree of decrease in polymerization activity due to the addition of additives can be minimized. As a result, an olefinic polymer can be produced with high activity. The amount of the phosphite compound (B) used is more preferably 0.5 ppm by mass or more and 50 mass ppm or less, and particularly preferably 1 mass ppm or more and 50 mass ppm or less.

The following examples further illustrate the present invention. However, the present invention is not limited to the description of the following examples.

[Stabilizer]
The stabilizers (component (B)) used in Examples and Comparative Examples are as follows.
"B-1": tris (4-nonylphenyl) phosphite (CAS number 26523-78-4, manufactured by Wako Pure Chemical Industries, Ltd.)
"B-2": tris (2,4-di-tert-butylphenyl) phosphite (CAS number 31570-04-4, manufactured by Tokyo Chemical Industry Co., Ltd.)
"TP": triphenylphosphine (CAS number 603-35-0, Wako Pure Chemical Industries, Ltd.)

[Preparation Example 1] (Preparation of solid catalyst component (X-1))
Silica gel (manufactured by Fuji Silysia Chemical Co., Ltd., average particle diameter 70 μm, specific surface area 340 m ² /g, pore volume 1.3 cm 3 /g, pore volume 1.3 cm ³ /g, at 250 ° C. time drying) was suspended in 77 L of toluene and then cooled to 0-5°C. While maintaining the temperature in the system at 0 to 5° C., 19.4 L of a toluene solution of methylaluminoxane (3.5 mol/L in terms of Al atoms) was added dropwise to this suspension over 30 minutes. After contacting each additive component for 30 minutes, the temperature in the system was raised to 95° C. over 1.5 hours, followed by contact at 93 to 97° C. for 4 hours. Thereafter, the temperature was lowered to room temperature, the supernatant was removed by decantation, and the mixture was washed twice with toluene to obtain a toluene slurry of the solid carrier in a total amount of 115 L. A portion of this slurry was sampled and analyzed to find that the solid concentration was 123 g/L.

Of the obtained slurry, 12.2 L (1.50 kg as solid content) was charged into a reactor with a stirrer having an internal volume of 114 L under a nitrogen atmosphere, and toluene was added so that the total amount was 28 L. Next, a solution of bis(1,3-n-butylmethylcyclopentadienyl)zirconium dichloride 23.5 g (54.2 mmol in terms of Zr atom) dissolved in toluene 5.0 L was pumped into the reactor. , at a system temperature of 20 to 25° C. for 1 hour. The supernatant was removed by decantation and washed with hexane three times. Thereafter, hexane was further added to bring the total amount to 30 L, thereby obtaining a hexane slurry of the solid catalyst component (X-1).

[Preparation Example 2] (Preparation of prepolymerized solid catalyst component (XP-1))
30 L of the hexane slurry of the solid catalyst component obtained in Preparation Example 1 was cooled to 10° C., and 2.89 mol of diisobutylaluminum hydride (DiBAl--H) was added thereto. While maintaining the temperature in the system at 10 to 15° C., ethylene was continuously supplied into the system under normal pressure for several minutes, and then 70 ml of 1-hexene was added. After that, ethylene supply was started at 1.46 kg/h, and preliminary polymerization was carried out at a system temperature of 32 to 37°C. A total of 70 ml of 1-hexene was added 5 times every 30 minutes after the start of prepolymerization, and when ethylene supply reached 4.37 kg 180 minutes after the start of prepolymerization, ethylene supply was stopped. After that, the supernatant was removed by decantation and washed four times with hexane. Thereafter, hexane was further added to bring the total amount to 30 L, thereby obtaining a hexane slurry of the prepolymerized solid catalyst component (XP-1).

Next, the hexane slurry was placed in an evaporative dryer with an internal volume of 43 L and equipped with a stirrer under a nitrogen atmosphere, decompressed to -68 kPaG over about 60 minutes, and vacuum-dried for about 4.3 hours when -68 kPaG was reached. , hexane and volatiles in the prepolymerized catalyst components were removed. Further, the pressure was reduced to -100 kPaG, and when -100 kPaG was reached, vacuum drying was performed for 8 hours to obtain 6.20 kg of prepolymerized solid catalyst component (XP-1).

[Example 1]
(Polymerization evaluation (i): Autoclave wall condition evaluation during polymerization)
500 ml of n-heptane was charged into a 1 L stainless steel autoclave sufficiently purged with nitrogen, the system was purged with ethylene, and 10 ml of 1-hexene was added to the prepolymerized solid catalyst component (XP-1) obtained in Preparation Example 2. 250 mg was added and the temperature was raised to 55°C. It took about 10 minutes from the addition of the prepolymerized solid catalyst component (XP-1) until the temperature reached 55°C. After that, 0.30 ml of a toluene solution (10 g/L) of tris(4-nonylphenyl)phosphite (B-1) as component (B) (amount of B-1: 3.0 mg) and a prepolymerized solid catalyst component ( 200 mg of XP-1) was added, and the temperature in the system was raised to 73°C. Then, polymerization was initiated by introducing ethylene, and the pressure was maintained at 8.0 kg/cm ² -G while continuously supplying ethylene, and polymerization was carried out for 90 minutes. After the polymerization was completed, the pressure was released, the polymer was removed, and the condition of the autoclave was checked.

(Polymerization evaluation (ii): polymerization activity evaluation)
500 ml of n-heptane was charged into a 1 L stainless steel autoclave sufficiently purged with nitrogen, the system was purged with ethylene, 20 ml of 1-hexene, and 0.06 ml of a decane solution of triisobutylaluminum (1.0 mol/L). was added and held at room temperature for 5 minutes. After that, 0.30 ml of a toluene solution (10 g/L) of tris(4-nonylphenyl)phosphite (B-1) as component (B) (amount of B-1: 3.0 mg) and a prepolymerized solid catalyst component ( 180 mg of XP-1) was added, and the temperature in the system was raised to 73°C. Then, polymerization was initiated by introducing ethylene, and the pressure was maintained at 8.0 kg/cm ² -G while continuously supplying ethylene, and polymerization was carried out for 90 minutes. After completion of the polymerization, the pressure was released, and the polymer was filtered, washed and dried under reduced pressure at 80°C for 10 hours to obtain 105.5 g of polymer. The amount of component (B-1) relative to the polymer yield (g) was 28 mass ppm, and the polymer yield (polymerization activity) per 1 g of catalyst was 586 (g-PE/g-cat).

[Examples 2 to 5 and Comparative Examples 1 to 4]
As shown in Tables 1 and 2, polymerization evaluation (i) and polymerization evaluation (ii) were carried out in the same manner as in Example 1, except that the type and/or amount of the stabilizer (component (B)) was changed. carried out. Results are shown in Tables 1 and 2.

As is clear from Table 1, in Examples 1 to 5 using component (B-1) or component (B-2), even with a relatively small addition amount, the wall of the autoclave and the stirring blade Adhesion of polymer could be suppressed. On the other hand, in Comparative Example 4 using component (TP), polymer adhesion could not be suppressed with a relatively small addition amount.

As is clear from Table 2, in Examples 1 to 5 in which the component (B-1) or component (B-2) was used in a relatively small amount, Comparative Examples 1 to 5 in which a relatively large amount was used Polymerization activity was higher than that of 3.

That is, in Examples 1-5, compared with Comparative Examples 1-4, olefin polymers could be stably produced with high polymerization activity.

[Preparation Example 3] (Preparation of prepolymerized solid catalyst component (XP-2))
10.0 g of the prepolymerized solid catalyst component (XP-1) obtained in Preparation Example 2 was placed in a reactor with an internal volume of 200 ml and equipped with a stirrer under a nitrogen atmosphere, and hexane was added to make the total amount 50 ml. Next, the temperature in the system is raised to 35° C., and then 5.0 ml of a hexane solution (10 g/L) of tris(4-nonylphenyl)phosphite (B-1) as component (B) (B- 1: 50 mg) was added, followed by contact at 32 to 37° C. for 2 hours to obtain a hexane slurry of the prepolymerized solid catalyst component (XP-2). This hexane slurry was transferred to a glass Schlenk tube having an internal volume of 100 ml, and hexane was distilled off under reduced pressure at 25° C. to obtain 10.1 g of prepolymerized solid catalyst component (XP-2).

[Example 6]
(Polymerization evaluation (i): Autoclave wall condition evaluation during polymerization)
500 ml of n-heptane was charged into a 1 L stainless steel autoclave sufficiently purged with nitrogen, the system was purged with ethylene, and 10 ml of 1-hexene was added to the prepolymerized solid catalyst component (XP-2) obtained in Preparation Example 3. 250 mg was added and the temperature was raised to 55°C. It took about 10 minutes from the addition of the prepolymerized solid catalyst component (XP-2) until the temperature reached 55°C. After that, 200 mg of the prepolymerized solid catalyst component (XP-2) was added, and the temperature in the system was raised to 73°C. Then, polymerization was initiated by introducing ethylene, and the pressure was maintained at 8.0 kg/cm ² -G while continuously supplying ethylene, and polymerization was carried out for 90 minutes. After the polymerization was completed, the pressure was released, the polymer was removed, and the condition of the autoclave was checked.

(Polymerization evaluation (ii): polymerization activity evaluation)
500 ml of n-heptane was charged into a 1 L stainless steel autoclave sufficiently purged with nitrogen, the system was purged with ethylene, 20 ml of 1-hexene, and 0.06 ml of a decane solution of triisobutylaluminum (1.0 mol/L). was added and held at room temperature for 5 minutes. After that, 180 mg of prepolymerized solid catalyst component (XP-2) was added, and the temperature in the system was raised to 73°C. Then, polymerization was initiated by introducing ethylene, and the pressure was maintained at 8.0 kg/cm ² -G while continuously supplying ethylene, and polymerization was carried out for 90 minutes. After completion of the polymerization, the pressure was released, and the polymer was filtered, washed and dried under reduced pressure at 80°C for 10 hours to obtain 103.6 g of polymer.

[Example 7]
(Polymerization evaluation (iii): operability evaluation by gas phase polymerization)
Copolymerization of ethylene and 1-hexene was carried out using a gas phase fluidized bed polymerization apparatus. The polymerization pressure was 1.7 MPaG, and the polymerization temperature was 80°C. The prepolymerized solid catalyst component (XP-1) prepared in Preparation Example 2 was fed into the polymerization reactor at 4.9 g/hr. Tris(4-nonylphenyl)phosphite (B-1) was fed as component (B) into the circulating gas line in an amount of 30 mass ppm relative to the mass of the polymer. The gas composition in the gas phase polymerization vessel is ethylene partial pressure = 1.0 MPa, hydrogen / ethylene = 4.8 × 10 ^-4 molar ratio, 1-hexene / ethylene = 0.022 molar ratio. , 1-hexene and isopentane were continuously supplied to produce a polymer at a rate of 6.0 kg/hr. The residence time was 4 hours. At this time, the polymer density was 916 kg/m ³ and the melt flow rate was 3.8 g/10 min. The melt flow rate was measured according to ASTM D1238-65T under the conditions of 190° C. and a load of 2.16 kg.

The operation was carried out for 48 hours under the above conditions, but no heat spots were observed in any part of the polymerization vessel, pipes, etc., and stable polymerization could be carried out.

[Comparative Example 5]
In the same manner as in Example 7, except that the supply amount of the prepolymerized solid catalyst component (XP-1) was 4.8 g/hr and the component (B-1) was not supplied, the rate was 6.0 kg/hr. to form a polymer. As a result of operating under these conditions, heat spots were generated in places such as the polymerization vessel, and the operation could not be continued after 4 hours.

According to the present invention, the decrease in the polymerization activity of olefin is reduced, the flowability inside the polymerization vessel is effectively secured without reducing the production rate, and the It is very useful as a method that enables stable operation with high activity over a long period of time.

Claims (4)

a solid catalyst component (A) for olefin polymerization, and
In the presence of a phosphite compound (B) represented by the following general formula (I),
A method for producing an ethylene polymer containing 50 mol% or more of an ethylene component by (co)polymerizing one or more olefins selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms in a polymerization vessel. hand,
A method for producing an ethylene polymer, characterized in that the phosphite compound (B) is supplied in an amount of 1 ppm by mass or more and 14 ppm by mass or less relative to the yield of the olefin polymer.

(In formula (I), R ¹ to R ⁵ are hydrogen atoms or hydrocarbon groups having 1 to 30 carbon atoms and may be the same or different.) 2. The method for producing an ethylene polymer according to claim 1, wherein the olefin is ethylene alone or ethylene and an α-olefin having 3 to 20 carbon atoms. 3. The method for producing an ethylene polymer according to claim 1, wherein the olefin (co)polymerization is carried out in suspension or in gas phase. Component (A) is
(A-1) a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl skeleton;
(A-2) (a) an organometallic compound,
(b) an organoaluminumoxy compound, and
(c) a compound that forms an ion pair by reacting with (A-1)
At least one compound selected from
(A-3) The method for producing an ethylene-based polymer according to any one of claims 1 to 3, further comprising a particulate carrier.