JP2613618B2 - Process for producing ethylene polymer and catalyst for producing ethylene polymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a granular polymer which can be polymerized with high activity, has a narrow composition distribution of a formed copolymer, a narrow particle size distribution, and a high polymer bulk density. The present invention relates to a method for producing an ethylene-based polymer capable of obtaining an ethylene-based polymer, and a catalyst for producing an ethylene-based polymer used in this process.

Technical background of the invention and its problems It is known that when ethylene and a small proportion of α-olefin are copolymerized using a Ziegler-type catalyst, an ethylene copolymer having a density similar to that of high-pressure polyethylene can be obtained. Have been. Generally, since the polymerization operation is easy, it is advantageous to employ a high-temperature dissolution polymerization in which a hydrocarbon solvent is used and the polymerization is carried out at a temperature equal to or higher than the melting point of the produced copolymer. However, in order to obtain a polymer having a sufficiently large molecular weight, the viscosity of the polymerization solution becomes high, so that the concentration of the polymer in the solution must be reduced. There is a problem that the sex has to be low.

On the other hand, when trying to obtain the low-density ethylene copolymer by a slurry polymerization method that is frequently used in the production of high-density polyethylene, the obtained copolymer is easily dissolved or swelled in a polymerization solvent, and the polymerization liquid In addition, not only the slurry concentration cannot be increased due to the increase in viscosity of the polymer, the adhesion of the polymer to the polymerization vessel wall, and the decrease in the bulk density of the polymer, but also the long-term continuous operation becomes impossible. . Further, the obtained copolymer had stickiness, and thus had a quality problem. Several methods have been proposed which attempt to solve such problems by using a specific catalyst and employing preliminary polymerization.

The present inventors have already studied a catalyst suitable for producing a low-density ethylene copolymer, and as a result, have found a catalyst system which is more excellent in slurry operability and can be operated at a high slurry concentration. On the other hand, many attempts have been made to improve the catalytic activity in producing a low-crystalline copolymer of ethylene and an α-olefin. For example, a method in which a vanadin compound having excellent copolymerizability is supported on a carrier, a method in which an oxidation reagent is added to improve the activity, a method in which the copolymerizability of a highly active supported titanium compound is improved, and the like. . However, these methods still have low polymerization activity and insufficient copolymerizability, and improvement has been desired.

Object of the Invention The present invention relates to homopolymerization of ethylene or ethylene and α
-Excellent polymerizability of slurry even when producing low density ethylene polymer by copolymerization with olefin,
Moreover, it is easy to use in gas phase polymerization, and it is possible to produce a copolymer having a narrow composition distribution, and when the obtained low-density ethylene copolymer is formed into a film or the like, transparency and blocking resistance are obtained. It is possible to produce a molded article excellent in heat sealability and the like, and it is possible to obtain such an excellent molded article even in a process in which all of the produced copolymer becomes a product such as gas phase polymerization. In addition, at the time of preparing a catalyst, it is desired to provide an ethylene-based polymer which has a high use efficiency of a catalyst raw material, and thus facilitates waste liquid treatment, and to provide a catalyst for producing an ethylene-based polymer used at that time. The purpose is.

SUMMARY OF THE INVENTION The method for producing an ethylene-based polymer according to the present invention comprises: (A) at least [I] (i) contacting a support made of an inorganic oxide with (ii) an organoaluminum compound in advance; A magnesium compound selected from the group consisting of MgX ₂ , Mg (OR) X, Mg (OR) ₂ and a carboxylate of magnesium (where X is a halogen and R is a hydrocarbon group) and an electron donor ( a) having a reducing ability selected from a solution formed from a hydrocarbon solvent or a solution formed from a magnesium compound selected from the group consisting of Mg (OR) ₂ and a carboxylate of magnesium and a hydrocarbon solvent; Magnesium-containing support obtained by contacting a magnesium compound in a liquid state without being reacted [II] selected from organoaluminum compounds and organomagnesium compounds Organometallic compounds of a reducing and _{[III] Ti (OR) g} X 4-g (R is a hydrocarbon group, X is halogen, 0 ≦ g ≦ 4) contacting the titanium compound in a liquid state represented by In the presence of a catalyst comprising a support-supported titanium catalyst component comprising magnesium, aluminum, halogen and titanium obtained by the reaction as essential components, and [B] a catalyst component comprising an organic metal compound of Group I to III Group A of the periodic table, ethylene Is polymerized or copolymerized.

In the present invention, at least 5 g or more of olefin per milligram atom of titanium in the titanium catalyst component [A] can be prepolymerized prior to polymerization or copolymerization of ethylene.

Ethylene can be polymerized or copolymerized by a gas phase polymerization method or a slurry polymerization method at a polymerization temperature in the range of 40 to 100 ° C. and a polymerization pressure in the range of ^{2 to} 50 kg / cm ² G.

The support (i) is desirably an inorganic oxide having a hydroxyl group.

Alcohols can be used as the electron donor (a).

The reducing organometallic compound [II] is preferably an organoaluminum compound.

The average valence of the titanium atom in the titanium catalyst component [A] is usually less than 4.

The average particle size of the titanium catalyst component [A] is preferably 10
100100 μm.

Ti / Mg (atomic ratio) in the titanium catalyst component [A] is more than 0.01 and 1 or less, Al / Mg (atomic ratio) is more than 1 and 3 or less, and halogen / Mg (atomic ratio) is more than 3 It is preferable that the weight ratio of RO group / Mg (R is a hydrocarbon group) is more than 1 and 15 or less.

The organometallic compound catalyst component [B] is preferably an organoaluminum compound.

Further, the catalyst for producing an ethylene polymer according to the present invention comprises the above-mentioned [A] support-supported titanium catalyst component and [B] an organometallic compound catalyst component of Group I or IIIA of the periodic table. . The catalyst for producing an ethylene polymer can be used in the main polymerization of ethylene after preliminarily polymerizing at least 5 g of olefin per 1 mg atom of titanium in the titanium catalyst component in the catalyst.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail.

In the present invention, the term polymerization may be used to include not only homopolymerization but also copolymerization, and the term polymer may be used to include not only homopolymers but also copolymers. There is.

First, the catalyst for producing an ethylene polymer used in the present invention will be specifically described.

FIG. 1 shows a flowchart of a catalyst component used in the present invention and a preparation process thereof.

The support-supported titanium catalyst component according to the present invention is obtained by a contact reaction between the above-mentioned [I] magnesium-containing support, [II] a reducing organometallic compound and [III] a titanium compound in a liquid state. ,aluminum,
Although halogen and titanium are essential components, typically, after contacting the support (i) with the organoaluminum compound (ii) in advance, the contact product is reduced to a liquid state magnesium compound (ii) having no reducing ability. ), Followed by a contact reaction with a reducing organometallic compound [II] and a liquid state titanium compound [III].

The support (i) that can be used in the present invention includes:
An inorganic porous support can be used, and this support preferably contains a hydroxyl group. As the inorganic support, an inorganic oxide is preferably used, and specifically,
SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, Ba
O, ThO ₂ or the like or a mixture thereof, for example, SiO ₂ -Mg
_{O, 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 or the like is used. Of these, SiO ₂
And a carrier containing at least one component selected from the group consisting of Al ₂ O ₃ as a main component. In addition, a small amount of Na ₂ CO ₃ , K ₂ CO ₃ , CaC
O ₃ , MgCO ₃ , Na ₂ SO ₄ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KNO ₃ , Mg
It may contain carbonate, sulfate, nitrate and oxide components such as (NO ₃ ) ₂ , Al (NO ₃ ) ₃ , Na ₂ O, K ₂ O and Li ₂ O.

The support which is such an inorganic oxide has different properties depending on the kind and production method, but the support preferably used in the present invention has an average particle size of 5 to 200 μm, preferably 10
-100 μm, specific surface area 50-1000 m ² / g, preferably 100-700 m ² / g, and pore volume 0.3-3.0 cm ³ / g, preferably 0.5-2.5 cm ³ / g. A support that is such an inorganic oxide is usually 150 to 1000 ° C., preferably 200 to 1000 ° C.
It can be used after firing at 800 ° C.

Among these supports, a porous inorganic oxide is particularly preferable.

By using the support (i) as described above, it is possible to relatively easily produce a polymer particle having a large particle diameter and a spherical shape. Therefore, the obtained polymer particles can be easily handled, and the destruction of the polymer particles is prevented, so that the adhesion of the fine powdery polymer to the polymerization wall surface or the pipe surface is also prevented.

In the present invention, first, the support as described above is brought into contact with the organoaluminum compound (ii) in advance. Specific examples of the organoaluminum compound (ii) used in this case include trialkylaluminums such as trimethylaluminum, triethylaluminum, and tributylaluminum; alkenylaluminums such as isoprenylaluminum; dimethylaluminum methoxide; diethylaluminum ethoxide; Dialkylaluminum alkoxides such as dibutylaluminum butoxide; alkylaluminum sesquialkoxides such as methylaluminum sesquimethoxide and ethylaluminum sesquiethoxide; partially alkoxylated having an average composition represented by R ¹ _2.5 Al (OR ² ) _0.5 Such as alkyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, dimethyl aluminum bromide Alkylaluminum halides, methyl aluminum sesquichloride, alkyl aluminum sesquihalide such as ethyl aluminum sesquichloride,
Methylaluminum dichloride, alkylaluminum dihalide such as ethylaluminum dichloride partially halogenated alkylaluminum, methylalumoxane, ethylalumoxane, isobutylalumoxane and partially halogenated methylalumoxane and the like Alumoxanes and the like are used.

As the organoaluminum compound, trialkylaluminum and dialkylaluminum chloride are preferable, and trimethylaluminum, triethylaluminum, triisobutylaluminum and diethylaluminum chloride are particularly preferable. Two or more of these organoaluminum compounds can be used.

When the support (i) is brought into contact with the organoaluminum compound (ii), the organoaluminum compound (ii) is contained in an amount of 0.1 to 100 milligram atoms, preferably 0.5 to 100 milligram atoms of aluminum in the organoaluminum compound per 1 g of the support.
It is used in an amount in the range of from 50 to 50 milligram atoms, more preferably 1 to 30 milligram atoms, particularly preferably 1.5 to 20 milligram atoms.

The contact between the support (i) and the organoaluminum compound (ii) is carried out, for example, by adding one or more of the above-mentioned organoaluminum compounds to an inert solvent in which the support is dispersed. 50 ° C or higher, preferably 10 to 200
C., more preferably at a temperature of 20 to 130 ° C. for 1 minute or more, preferably 20 minutes to 5 hours, more preferably 30 minutes to 3 hours, by bringing them into contact under normal pressure, reduced pressure or increased pressure. .

When the support (i) is brought into contact with the organoaluminum compound (ii), the support (i) is usually placed in a reaction volume of 1: 1.
It is preferably carried out while dispersing in an inert solvent in an amount of from 10 to 800 g, preferably from 50 to 400 g.

When the support (i) is brought into contact with the organoaluminum compound (ii), examples of the inert solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, tetradecane, and kerosene. Cyclopentane, methylcyclopentane, cyclohexane,
Alicyclic hydrocarbons such as methylcyclohexane, cyclooctane and cyclohexene; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene and cymene; dichloroethane, dichloropropane, trichloroethylene, carbon tetrachloride, chlorobenzene And the like.

The free organoaluminum compound or its reactant which is not fixed on the support by the contact between the support (i) and the organoaluminum compound (ii) can be removed by a decantation method or an excessive method. preferable.

Next, the support (i) and the organoaluminum compound (ii) are brought into contact in advance in this way, and then contacted with the magnesium compound in a liquid state having no reducing ability, whereby the magnesium-containing support is obtained. can get.

Liquid state magnesium compound having no reducing ability (ii
As i), for example, a magnesium compound dissolved in a hydrocarbon, an electron donor (a) or a mixture thereof, or a hydrocarbon solution of a magnesium compound is used.

Magnesium compounds used in this case include magnesium chloride, magnesium bromide, magnesium iodide,
Magnesium halides such as magnesium fluoride; alkoxy magnesium halides such as methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy magnesium chloride, octoxy magnesium chloride; allyloxy magnesium halides such as phenoxy magnesium chloride, methylphenoxy magnesium chloride; Alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, octoxymagnesium, 2-ethylhexoxymagnesium; phenoxymagnesium;
Allyloxymagnesium such as dimethylphenoxymagnesium; magnesium carboxylate such as magnesium laurate and magnesium stearate are used. Further, the magnesium compound may be a complex compound with another metal, a double compound, or a mixture with another metal compound. Further, a mixture of two or more of these compounds may be used.

Among these preferred magnesium compounds,
Magnesium halide, alkoxymagnesium halide, allyloxymagnesium halide represented by MgX ₂ , Mg (OR ⁵ ) X, Mg (OR ⁵ ) ₂ (where X is a halogen and R ⁵ is a hydrocarbon group); Alkoxy magnesium and allyloxy magnesium are used, and halogen-containing magnesium compounds, particularly magnesium chloride, alkoxy magnesium chloride, allyloxy magnesium chloride, particularly magnesium chloride are preferably used.

As the magnesium compound (iii) in a liquid state, as described above, a magnesium compound solution obtained by dissolving the magnesium compound in a hydrocarbon solvent or the electron donor (a), or the above-mentioned hydrocarbon solvent is used. A magnesium compound solution obtained by dissolving the magnesium compound in a mixture with the electron donor (a) is preferable.
Specifically, as the magnesium compound (iii) in a liquid state having no reducing ability, a magnesium compound selected from the group consisting of MgX ₂ , Mg (OR) X, Mg (OR) ₂ and a carboxylate of magnesium (where X is A halogen compound wherein R is a hydrocarbon group), a solution formed from an electron donor (a) and a hydrocarbon solvent, or a magnesium compound selected from the group consisting of Mg (OR) ₂ and magnesium carboxylate And a solution formed from a hydrocarbon solvent.

As the hydrocarbon solvent used at this time, pentane,
Aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, tetradecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane, and cyclohexene; benzene, toluene, Xylene,
Examples thereof include aromatic hydrocarbons such as ethylbenzene, cumene, and cymene; and halogenated hydrocarbons such as dichloroethane, dichloropropane, trichloroethylene, carbon tetrachloride, and chlorobenzene.

In order to dissolve the magnesium compound as described above in a hydrocarbon solvent, although it depends on the type of the magnesium compound and the solvent, a method of simply mixing the hydrocarbon solvent and the magnesium compound (for example, R ⁵ having 6 to 20 carbon atoms).
Mg (OR ⁵ ) ₂ ), a method of heating after mixing a hydrocarbon solvent and a magnesium compound, an electron donor (a) capable of dissolving the magnesium compound, for example, alcohol, aldehyde, amine, carboxylic acid , A mixture of these, and a mixture of these with another electron donor, etc., in a hydrocarbon solvent, and mixing a mixture of the hydrocarbon solvent with the electron donor (a) and a magnesium compound, Depending on the method, a heating method or the like can be adopted. For example, as a liquid magnesium compound (iii) having no reducing ability, a halogen-containing magnesium compound such as a hydrocarbon solution of a complex compound of magnesium chloride and an electron donor as shown in FIG. 1 is prepared. Is dissolved in a hydrocarbon solvent using an alcohol as the electron donor (a). The alcohol varies depending on the type and amount of the hydrocarbon solvent, the type of the magnesium compound, and the like. About 0.5 mol or more, preferably about 1 to about 20 mol, more preferably about 1.5 to about 12 mol, per mol of the compound,
Particularly preferably, it is used in a range of about 1.8 to 4 mol. The amount of the alcohol slightly varies depending on the type of the hydrocarbon solvent used. When an aliphatic hydrocarbon and / or an alicyclic hydrocarbon is used as the hydrocarbon, the alcohol having 6 or more carbon atoms is replaced with a halogen-containing magnesium. Compound 1
It is preferable to use about 1 mol or more, preferably about 1.5 mol or more with respect to the mol, because the total amount of the alcohol used is small, so that the halogen-containing magnesium compound can be solubilized and the catalyst component has a good shape. On the other hand, for example, when only an alcohol having 5 or less carbon atoms is used, a large amount of alcohol is required for 1 mole of the halogen-containing magnesium compound. On the other hand, if an aromatic hydrocarbon is used as the hydrocarbon, the amount of alcohol required for solubilizing the halogen-containing magnesium compound can be reduced regardless of the type of alcohol.

The contact between the halogen-containing magnesium compound and the alcohol is preferably performed in a hydrocarbon medium, and is usually-
50 ° C. or higher, depending on the type thereof, at a temperature of about room temperature or higher, preferably about 80 to 300 ° C., more preferably about 100 to 200 ° C., usually for 1 minute or more, preferably 15 minutes to 5 hours. For about 30 minutes to 2 hours.

As the alcohol, specifically, an alcohol having 6 or more carbon atoms is preferably used, and examples thereof include 2-methylpentanol, 2-ethylbutanol, n-heptanol, and n-heptanol.
-Octanol, 2-ethylhexanol, decanol, dodecanol, tetradecyl alcohol, undecenol, oryl alcohol, aliphatic alcohols such as stearyl alcohol, cyclohexanol, alicyclic alcohols such as methylcyclohexanol, benzyl alcohol, methylbenzyl alcohol, Isopropylbenzyl alcohol, α-methylbenzyl alcohol,
Aromatic alcohols such as α, α-dimethylbenzyl alcohol and the like, aliphatic alcohols containing an alkoxy group such as n-butyl cellosolve, 1-butoxy-2-propanol and 1-butoxy-6-hexanol are used. As the alcohol other than the above, alcohols having 5 or less carbon atoms such as methanol, ethanol, propanol, butanol, ethylene glycol and methyl carbitol are used.

The hydrocarbon solvent has a concentration of the magnesium chloride compound in the solution (iii) of 0.1 to 10 mol /, more preferably
It is used in an amount of 0.5 to 3 mol /.

When the contact product of the support (i) and the organoaluminum compound (ii) is brought into contact with a liquid state magnesium compound having no reducing ability, the liquid state magnesium compound having no reducing ability is, for example, a support. The amount of magnesium in the magnesium compound (iii) in a liquid state is usually 0.1 g atom or more, preferably about 0.1 to about 6 g atom, particularly preferably about 0.5 to about 3 g atom per 1 g atom of aluminum in the aluminum compound. Used in such amounts. Further, such a contact reaction may occur when the support is, for example,
It can be carried out under conditions present at a concentration of from 10 to 800 g /, preferably from 50 to 400 g /. A hydrocarbon solvent to be described later can be appropriately added so as to have such a concentration.

The contact reaction as described above is usually carried out at a temperature of -50 ° C or higher, preferably room temperature to 200 ° C, more preferably 30 to 100 ° C, and usually 1 minute or more, more preferably 30 minutes to 3 hours. This is done by contact.

The support-supported titanium catalyst component according to the present invention is obtained by contacting the magnesium-containing support [I], the reducing organometallic compound [II] and the titanium compound [III] in a liquid state obtained as described above. Is obtained by

Examples of the method of contacting each of these components include a method in which a magnesium-containing support [I] and an organometallic compound [II] are brought into contact with each other, and then a titanium compound [III] is brought into contact with the magnesium-containing support [I]. ] And a titanium compound [III] and then an organometallic compound [II] or a magnesium-containing support [I], an organometallic compound [II] and a titanium compound [III] simultaneously. Can be exemplified. In performing such contact, a hydrocarbon solvent as described below can be used.

When the above components are brought into contact with each other, the organometallic compound [II] is, for example, 0.1 to 10 g atoms, preferably 0.3 to 5 g atoms, particularly preferably 0.3 to 5 g atoms, per 1 g of magnesium in the magnesium-containing support [I]. Preferably 0.5
And the titanium compound [III] is usually used in an amount of less than 2, preferably 0.01 to 1.5, particularly preferably 0.08 to 1.2. When the above components are brought into contact with each other, the magnesium-containing support [I] is used at a concentration of, for example, 10 to 800 g /, preferably 50 to 400 g /, using the magnesium-containing support. be able to. A hydrocarbon solvent described below can be used as appropriate so as to have such a concentration. Further, the contact reaction is carried out, for example, usually at a temperature of -50 ° C or higher, preferably at room temperature to 200 ° C, more preferably at a temperature of 30 to 100 ° C,
Usually, it is carried out for 1 minute or more, more preferably for about 30 minutes to 3 hours.

Examples of the organometallic compound [II] that can be used in the above-mentioned catalytic reaction include an organoaluminum compound component used in the polymerization of an olefin as described below or the above-described organoaluminum compound (ii) and an organic magnesium such as a Grignard reagent and dialkylmagnesium. Compounds. Of these, organoaluminum compounds are preferred. Among the organoaluminum compounds, a trialkylaluminum or a dialkylaluminum halide is particularly preferable, and these can be used in combination.

The titanium compound [III] in a liquid state is generally a tetravalent compound represented by Ti (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, and 0 ≦ g ≦ 4). Are preferred. More specifically, TiCl ₄ , TiBr ₄ , TiI ₄
Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (On-C ₄ H ₉ ) C
_{l 3, Ti (Oiso-C} 4 H 9) Cl 3, Ti (OC 2 H 5) Br 3, Ti (Oiso
_{-C 4 H 9) Br 3,} Ti (O2- ethylhexyl) trihalide, alkoxy titanium such as _{Cl 3; Ti (OCH 3)} 2 Cl 2, Ti (OC 2 H 5) 2 Cl 2, Ti (On-C ₄ H _{9) 2
Cl 2, Ti (OC 2 H} 5) dihalogenated alkoxy titanium such as _{2 Br 2; Ti (OCH 3} ) 3 Cl, Ti (OC 2 H 5) 3 Cl, Ti (On-C 4 H 9) 3 C
l, monohalogenated trialkoxy titanium such as Ti (OC ₂ H ₅ ) ₃ Br; Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C ₄ H ₉ ) ₄ , T
_{i (Oiso-C 4 H 9} ) 4, Ti (O2- ethylhexyl) ₄ tetraalkoxy titanium or these and aluminum compounds such as may be used mixtures with other metal compounds of silicon compounds.

Furthermore, a trivalent titanium compound represented by Ti (OR) _h X _3-h (R is a hydrocarbon group, X is a halogen, and 0 ≦ h ≦ 3) can also be used. When the trivalent titanium compound is not in a liquid state, the titanium compound can be used in a liquid state by dissolving the titanium compound in hydrocarbon, alcohol, ether, or the like. These trivalent titanium compounds include, for example, Ti
Cl ₃ , Ti (OC ₂ H ₅ ) ₃ , Ti (On-C ₄ H ₉ ) ₃ , Ti (Oiso-C ₄
Compounds such as H ₉ ) ₃ , Ti (O 2 -ethylhexyl) ₃ , and Ti (O ₂ -ethylhexyl) Cl ₂ are used.

As the titanium compound [III] in the liquid state that can be used in the present invention, a tetravalent titanium compound is preferable, and a halogen-containing tetravalent titanium compound is particularly preferable.

When the titanium compound is in a liquid state, the titanium compound [III] in a liquid state may be used as it is, or a mixture thereof, or may be used by dissolving the titanium compound in a solvent such as a hydrocarbon. You may.

In the support-supported titanium catalyst component thus obtained, the Ti / Mg (atomic ratio) is usually greater than 0.01 and less than or equal to 1, preferably greater than 0.05 and less than or equal to 0.6.
(Atomic ratio) is more than 0.5 and 4 or less, preferably more than 1 and 3 or less, and halogen / Mg (atomic ratio) is 2
Greater than 10 and preferably greater than 3 and less than or equal to 6, and the RO group / Mg (R is a hydrocarbon group) is greater than 1 and less than or equal to 15 by weight, preferably greater than 1.5 and less than or equal to 10;
Particularly preferably 6 or less larger than 2, also a specific surface area of 50~1000m ² / g, preferably from 100 to 500 m ² / g.
The average valence of Ti is usually less than 4, preferably 3.5 to 2.5. The particle size of the titanium catalyst component is usually 5 to 200 μm, preferably 10 to 100 μm, particularly preferably 20 to 60 μm, and the particle size distribution is a geometric standard deviation, usually in the range of 1.0 to 2.0.

In preparing the titanium catalyst component of the present invention, examples of the hydrocarbon solvent that can be used include pentane, hexane, heptane, octane, decane, dodecane, tetradecane, and aliphatic hydrocarbons such as kerosene; cyclopentane;
Alicyclic hydrocarbons such as methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane and cyclohexene; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene and cymene; dichloroethane, dichloropropane, trichloroethylene; Examples thereof include halogenated hydrocarbons such as carbon tetrachloride and chlorobenzene.

In the present invention, when performing polymerization of ethylene or copolymerization of ethylene and an α-olefin, the above-mentioned titanium catalyst component [B] used in the periodic table I or
The group IIIA organometallic compound catalyst component is preferably an organoaluminum compound, which is a compound having at least one Al-carbon bond in the molecule. For example, (i) a compound represented by the general formula R ¹ _m Al ( OR ² ) _n H _P X _q (where R ¹ and R ² are usually 1 to 15, preferably 1 to
A hydrocarbon group containing 4 carbon atoms, which may be the same or different. X is a halogen, and m is 0 <m ≦
3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is 0 ≦ q <3, and m + n + p + q =
3, an organoaluminum compound represented by (i.
i) the general formula M ¹ AlR ¹ ₄ (wherein M ¹ is Li, Na, K, R ¹ is and the like alkylated complex of a Group 1 metal and aluminum represented by the same in a) and the Can be.

The following can be exemplified as the organoaluminum compound belonging to the above (i).

General formula R ¹ _m Al (OR ² ) _3-m (where R ¹ and R ² are the same as above, m is preferably a number satisfying 1.5 ≦ m <3), General formula R ¹ _m AlX _{3 -m} (where R ¹ is the same as above. X
Is a halogen, m is preferably 0 <m <3), and a general formula R ¹ _m AlH _3-m (where R ¹ is the same as described above.
Is preferably 2 ≦ m <3), and a general formula R ¹ _m Al (OR ² ) _{n Xq} (where R ¹ and R ² are the same as above. X is a halogen, and 0 <m ≦ 3, 0 ≦ n
<3, 0 ≦ q <3, and m + n + q = 3).

As the aluminum compound belonging to (i), more specifically, trialkylaluminum such as triethylaluminum and tributylaluminum, trialkenylaluminum such as triisoprenylaluminum,
Diethylaluminum ethoxide, dialkylaluminum alkoxides such as dibutyl aluminum butoxide, ethyl aluminum sesqui ethoxide, in addition to alkylaluminum sesqui alkoxides such as butyl sesquichloride butoxide, an average composition represented by such _{^{R 1 2.5 Al (OR 2)}} 0.5 Having partially alkoxylated alkylaluminum, diethylaluminum chloride, dibutylaluminum chloride, dialkylaluminum halide such as diethylaluminum bromide, ethylaluminum sesquichloride, butylaluminum sesquichloride, alkylaluminum sesquibromide such as ethylaluminum sesquibromide , Ethyl aluminum dichloride, propyl aluminum dichloride, butyl alcohol Partially halogenated alkyl aluminum such as alkyl aluminum dihalide such as luminium dibromide, dialkyl aluminum hydride such as diethyl aluminum hydride, dibutyl aluminum hydride, alkyl aluminum dihydride such as ethyl aluminum dihydride, propyl aluminum dihydride and the like. Partially hydrogenated alkylaluminums such as hydrides, partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxycyclolide, butylaluminum butoxycyclolide, ethylaluminum ethoxybromide are used.

As a compound similar to (i), an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom is used. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl (C ₂ H ₅ ) ₂ , (C ₄ H ₅ ) ₂ AlOAl (C ₄ H ₉ ) ₂ , And the like.

As the compound belonging to the above (ii), LiAl (C
_{2 H 5) 4, LiAl (} C 7 H 15) 4 etc. can be exemplified.

Among these compounds, the average composition is R _n AlX _3-n (where R is an alkyl group, X is a halogen,
Preferred examples include the above-mentioned organoaluminum compound or a mixture of the above-mentioned organoaluminum and aluminum trihalide arbitrarily so as to satisfy 2 ≦ n ≦ 3). Further, in the formula, an organoaluminum compound satisfying 2.1 ≦ n ≦ 2.9, wherein R is an alkyl group having 1 to 4 carbon atoms and X is chlorine, is particularly preferably used.

[B] Examples of the organometallic compound catalyst components of Groups I to IIIA of the periodic table include, besides organoaluminum, for example, organozinc, organoboron, organoberyllium, organolithium and organomagnesium exemplified as organometallic compound [II]. Etc. can also be used.

The catalyst for producing an ethylene polymer catalyst comprising the [A] support-supported titanium catalyst component and [B] the organometallic catalyst component of Group A or IIIA of the periodic table has a specific amount of ethylene as described later. Alternatively, ethylene and an α-olefin can be preliminarily polymerized.

Next, a method for producing an ethylene-based polymer using the above-described catalyst for producing an ethylene-based polymer will be described.

In the present invention, an ethylene homopolymer or ethylene is prepared by using a catalyst comprising the above-mentioned [A] support-supported titanium catalyst component and [B] an organometallic compound catalyst component of Group A or IIIA of the periodic table. Copolymers with other olefins can be produced, and copolymers of ethylene and polyene or copolymers of ethylene, α-olefin and polyene can be produced. Examples of the olefin that can be used for the polymerization in the present invention include, in addition to ethylene, propylene, 1-butene, 1-pentene,
Examples thereof include 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 3-methyl-1-butene, 1-octene, and 1-decene. Examples of the polyene include butadiene, isoprene, hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and the like.

In the present invention, it is preferable to produce a copolymer containing about 70% by weight or more of ethylene. In the present invention, in particular, ethylene and a small amount of α-olefin are copolymerized to have a density of 0.880 to 0.970 g / cm ³ , particularly 0.890
It is preferable to produce a low-density ethylene copolymer having a density of 0.940 g / cm ³ by slurry polymerization or particularly by gas phase polymerization.

The polymerization of the olefin can be carried out in the liquid or gas phase in the presence or absence of an inert solvent. Examples of inert solvents that can be used for polymerization include propane, butane, pentane, hexane, octane, decane,
Examples include aliphatic hydrocarbons such as kerosene; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

In the case of producing an ethylene copolymer having a particularly low density, it is preferable to employ a gas phase polymerization method.

The amount of each catalyst component used in conducting the olefin polymerization reaction can be appropriately changed or selected. For example, the amount of the titanium catalyst component is preferably about 0.0001 to about 1 mmol in terms of titanium atom per reaction volume. More preferably from about 0.001 to about 0.5 mmol and the organoaluminum compound is aluminum /
Titanium (atomic ratio) is about 1 to about 2000, preferably about 5 to about 2000
It is preferable to use an amount such that it becomes 100. The polymerization temperature is
Preferably it is 20 to 150 ° C, particularly preferably 40 to 100 ° C.
The polymerization pressure is from atmospheric pressure to about 100 kg / cm ² -G, preferably from about 2 to about 50 kg / cm ² -G.

In olefin polymerization, it is preferable to make hydrogen coexist in the reaction system in order to adjust the molecular weight.

The polymerization can be carried out batchwise or continuously. Further, it can be performed in two or more stages under different conditions.

In the present invention, at least prior to producing an ethylene polymer using the above-mentioned [A] support-supported titanium catalyst component and [B] organometallic compound catalyst component of Group A or IIIA of the periodic table, at least titanium In the presence of a catalyst component and an organoaluminum compound component, usually 5 g or more, preferably 10 to 10 g, per 1 mg atom of titanium in the titanium catalyst component.
It is preferable to carry out the prepolymerization of ethylene or ethylene and an α-olefin at a polymerization amount of 3000 g, particularly preferably 20 to 1000 g.

The prepolymerization can be performed in the presence or absence of an inert hydrocarbon solvent. That is, the preliminary polymerization can be performed by slurry polymerization or gas phase polymerization. As the inert hydrocarbon solvent, the above-mentioned hydrocarbon solvents are used, and among them, an aliphatic hydrocarbon having 3 to 10 carbon atoms or an alicyclic hydrocarbon having 5 to 10 carbon atoms is particularly preferably used.

As the α-olefin used when performing the prepolymerization, ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, Α-olefins having 10 or less carbon atoms, such as 1-decene, are preferred, and α-olefins having 2 to 6 carbon atoms are more preferred. Particularly, ethylene alone or a combination of ethylene and the above α-olefin is preferred. These α-olefins may be used alone or as a mixture of two or more as long as a crystalline polymer is produced.

The polymerization temperature in the prepolymerization is generally −40 to 100 ° C.,
Preferably it is -20 to 60C, more preferably -10 to 40C. Hydrogen can be allowed to coexist in the prepolymerization.

In carrying out the prepolymerization, the catalyst component of the organometallic compound belonging to Group I to IIIA of the Periodic Table [B] typified by organoaluminum is usually at least 0.1 g per gram atom of titanium in the titanium catalyst component. Atoms or more, preferably from 0.5 gram atom to 200 gram atom, more preferably about 1 gram atom
It is used in an amount such that it is between 30 g atoms and 30 g atoms.

In conducting the prepolymerization, various electron donor components as described above may be allowed to coexist.

Effects of the Invention According to the present invention, it is possible to polymerize an olefin with high activity, and to obtain a granular olefin polymer having a narrow composition distribution of a produced copolymer, a narrow particle size distribution, and a high polymer bulk specific gravity. Can be.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 [Preparation of titanium catalyst component] 10 g of Fujidebison silica (F952) calcined at 200 ° C for 2 hours and then at 700 ° C for 5 hours was suspended in 40 ml of purified n-decane. aluminum
After addition of 50 ml of an n-decane solution containing 50 mmol, the resulting suspension was stirred at 90 ° C. for 2 hours to effect a contact reaction between silica and triethylaluminum.

After completion of the reaction, a solid portion was separated from the reaction solution by filtration. The solid portion obtained contains aluminum per gram of silica.
It contained 1.1 mmol atom equivalent. After resuspending 9.0 g of this solid portion with 100 ml of n-decane, the resulting suspension was
48 g of magnesium chloride, 197 g of 2-ethylhexanol and 175 g of n-decane were heated and stirred at 140 ° C. for 2 hours, and 6.4 ml of a magnesium chloride decane solution (corresponding to about 6.4 mmol of Mg) was added, followed by heating to 80 ° C. About 1 hour later, 7.7 mmol of diethylaluminum chloride was added, and the reaction was further carried out at 80 ° C. for 1 hour. Next, a solid portion was separated from the reaction solution by filtration, and the solid portion was separated into n-decane.
After resuspension in 100 ml, 1.9 mmol of mono-2-ethylhexoxytrichlorotitanium was added, and the mixture was stirred at 80 ° C. for 1 hour to perform a contact reaction. Subsequently, the solid portion was separated by filtration and washed twice with 100 ml of hexane to prepare a titanium catalyst component [A].

The amount of titanium carried in the obtained titanium catalyst component was 0.5% by weight.

[Preliminary polymerization] In a 400 ml cylindrical flask equipped with a stirrer, 200 m of purified hexane was added.
l, 0.6 mmol of triethylaluminum and the above-mentioned titanium catalyst component [A] are added in an amount of 0.2 mmol in terms of titanium atoms, and then ethylene is supplied at 30 ° C at a rate of 8 Nl / hour for 3 hours to carry out prepolymerization of ethylene. Was performed. The amount of polyethylene produced was 142 g per mmol Ti.

[Ethylene polymerization] 150 g of sodium chloride was added as a dispersant to a sufficiently nitrogen-purged autoclave having an internal volume of 2 and heated to 90 ° C, and then subjected to a pressure reduction treatment with a vacuum pump for 2 hours so that the internal pressure of the autoclave became 50 mmHg or less. Done. Then, after lowering the temperature of the autoclave to room temperature and replacing the inside of the autoclave with ethylene, 0.5 mmol of triethylaluminum, 0.5 mmol of diethylaluminum chloride and 19 ml of hexene-19 were added, and the system was sealed.
The temperature was raised, 1 kg / cm ² of hydrogen was added at 60 ° C., and the catalyst component subjected to the prepolymerization was added in an amount of 0.005 mmol in terms of titanium atoms while further pressurizing with ethylene. During polymerization, the temperature is 80 ℃
The pressure was maintained at 8 kg / cm ² G by replenishing ethylene gas. After addition of the titanium catalyst component, hexene-1 36 ml
Was supplied using a pump for one hour. The polymerization was completed one hour after the addition of the titanium catalyst.

After the completion of the polymerization, the contents of the autoclave were put into about 1 of water. After stirring for about 5 minutes, almost all of the sodium chloride was dissolved in water, and only the polymer floated on the water surface. The suspended polymer was collected, sufficiently washed with methanol, and dried at 80 ° C. under reduced pressure overnight.

Table 1 shows the composition and polymerization results of the obtained titanium catalyst components.
It was shown to.

Examples 2 to 10 Except that 50 mmol of triethylaluminum and 7.7 mmol of diethylaluminum chloride used in the preparation of the titanium catalyst of Example 1 were replaced with the compounds shown in Table 1,
A titanium catalyst was prepared in the same manner as in Example 1, and prepolymerization and copolymerization of ethylene and hexene-1 were performed.

 Table 1 shows the composition of the obtained catalyst and the polymerization results.

The methylalumoxane used in Example 5 was synthesized by the following method.

Synthesis of Aluminoxane Al ₂ (SO ₄ ) ₃ .14H ₂ O 74 g and toluene 250 ml were placed in a glass flask equipped with a stirrer sufficiently purged with nitrogen and cooled to 0 ° C., and then trimethylaluminum 100 ml was added.
Was added dropwise over 1.5 hours. Then, the temperature was raised to 40 ° C. over 2 hours, and the reaction was continued at that temperature for 48 hours. After the reaction, solid-liquid separation was carried out by filtration to remove low-boiling substances from the separated liquid using an evaporator, and toluene was added to the residue to collect a toluene solution. The molecular weight of aluminoxane determined from the freezing point depression of benzene is
891.

Examples 11 to 12 A titanium catalyst was prepared in the same manner as in Example 1, except that the mono-2-ethylhexoxytrichlorotitanium used in the preparation of the titanium catalyst in Example 1 was replaced with the compound shown in Table 2. Preliminary polymerization was performed, and ethylene and hexene-1 were copolymerized.

Example 13 In the same manner as in Example 1, 10 g of silica was reacted with 50 mmol of triethylaluminum to prepare a treated carrier in which aluminum was fixed at 1.3 mmol atoms per 1 g of silica. After resuspending this treated carrier in 100 ml of n-decane, 104.8 g of ethoxymagnesium chloride was added.
140 g of 390 g of ethylhexanol and 355 g of n-decane
6.4 ml of a decane solution of magnesium obtained by heating and reacting at 2 ° C for 2 hours was added, and the temperature was raised to 80 ° C. After about 1 hour, the temperature was lowered to 55 ° C and 30 ml of silicon tetrachloride was added. The reaction was performed. Next, the solid portion was separated by filtration and resuspended in 100 ml of n-decane. Then, 7.7 mmol of diethylaluminum chloride was added, and the reaction was carried out at 80 ° C. for 1 hour. Thereafter, a supporting reaction of a titanium compound was carried out in the same manner as in Example 1 to prepare a titanium catalyst component, and prepolymerization and copolymerization of ethylene and hexene-1 were carried out in the same manner as in Example 1.

 Table 2 shows the catalyst composition and the polymerization results.

Example 14 In Example 13, ethoxymagnesium chloride
104.8 g, 390 g of 2-ethylhexanol and n-decane
A catalyst was prepared in the same manner as in Example 13 except that the decane solution of magnesium obtained by heating and reacting 355 g at 140 ° C. for 2 hours was replaced with a heptane solution containing 6.4 mmol of magnesium bis 2-ethylhexoxide. Then, prepolymerization and copolymerization of ethylene and hexene-1 were performed.

 Table 2 shows the catalyst composition and the polymerization results.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the catalyst components used in the present invention and the preparation steps.

Claims (12)

(57) [Claims] [A] [A] At least [I] (i) After contacting an organoaluminum compound with a support made of an inorganic oxide in advance, (iii) MgX ₂ , Mg (OR) X, Mg (OR) a magnesium compound selected from the group consisting of ₂ and magnesium carboxylate (where X is a halogen and R is a hydrocarbon group), an electron donor (a), and a hydrocarbon solvent. Or a solution of a magnesium compound selected from the group consisting of Mg (OR) ₂ and magnesium carboxylate and a solution formed from a hydrocarbon solvent, and a liquid state magnesium compound having no reducing ability selected from the group consisting of hydrocarbon solvents. [II] Reducing organometallic compound selected from organoaluminum compounds and organomagnesium compounds and [III] Ti (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, 0 ≦ g ≦ 4) magnesium, aluminum, halogen and titanium obtained by a contact reaction with a titanium compound in a liquid state represented by 0 ≦ g ≦ 4 Wherein ethylene is polymerized or copolymerized in the presence of a catalyst comprising a support-supporting titanium contact component comprising, as an essential component, and [B] an organometallic compound catalyst component of Group A or IIIA of the Periodic Table. A method for producing an ethylene-based polymer or copolymer. 2. The method according to claim 1, wherein the polymerization or copolymerization of ethylene is
2. The method according to claim 1, wherein at least 5 g or more of olefin is prepolymerized per 1 mg atom of titanium in the titanium catalyst component [A]. 3. The polymerization or copolymerization of ethylene is 40 to 100.
The process according to claim 1 or 2, wherein the process is carried out by a gas phase polymerization method or a slurry polymerization method at a polymerization temperature in the range of ° C and a polymerization pressure in the range of ^{2 to} 50 kg / cm2G. 4. The method according to claim 1, wherein the electron donor (a) is an alcohol. 5. The process according to claim 1, wherein the average valence of the titanium atom in the titanium catalyst component [A] is less than 4. 6. The titanium catalyst component [A] has an average particle size of 10 to 10.
The method according to claim 1, wherein the thickness is 100 µm. 7. The method according to claim 1, wherein the support (i) is an inorganic oxide having a hydroxyl group. 8. The method according to claim 1, wherein the reducing organometallic compound [II] is an organoaluminum compound. 9. The titanium catalyst component [A] has a Ti / Mg (atomic ratio) of more than 0.01 and not more than 1 and an Al / Mg (atomic ratio) of 1
The halogen ratio is greater than 3 and the halogen / Mg (atomic ratio) is greater than 3 and 6 or less, and the weight ratio of the RO group / Mg (R is a hydrocarbon group) is greater than 1 and 15 or less. The manufacturing method described. 10. The process according to claim 1, wherein the catalyst component [B] the organometallic compound of Group I to III of the periodic table is an organoaluminum compound. 11. [A] At least [I] (i) After contacting an organoaluminum compound in advance with a support made of an inorganic oxide, (iii) MgX ₂ , Mg (OR) X, Mg (OR) a magnesium compound selected from the group consisting of ₂ and magnesium carboxylate (where X is a halogen and R is a hydrocarbon group), an electron donor (a), and a hydrocarbon solvent. Or a solution of a magnesium compound selected from the group consisting of Mg (OR) ₂ and magnesium carboxylate and a hydrocarbon solvent and a liquid state magnesium compound having no reducing ability selected from a solution formed from a hydrocarbon solvent. [II] A reducing organometallic compound selected from organoaluminum compounds and organomagnesium compounds, and [III] Ti (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, and 0 ≦ g ≦ 4). A catalyst for producing an ethylene polymer, comprising a support-contacting titanium component having titanium as an essential component, and [B] a catalyst component of an organometallic compound belonging to Group A or IIIA of the periodic table. 12. [A] At least [I] (i) After contacting an organoaluminum compound in advance with a support made of an inorganic oxide, (iii) MgX ₂ , Mg (OR) X, Mg (OR) a magnesium compound selected from the group consisting of ₂ and magnesium carboxylate (where X is a halogen and R is a hydrocarbon group), an electron donor (a), and a hydrocarbon solvent. Or a solution of a magnesium compound selected from the group consisting of Mg (OR) ₂ and magnesium carboxylate and a solution formed from a hydrocarbon solvent, and a liquid state magnesium compound having no reducing ability selected from the group consisting of hydrocarbon solvents. [II] A reducing organometallic compound selected from an organoaluminum compound and an organomagnesium compound, and [III] _{Ti (OR) g X 4-} g (R is a hydrocarbon group, X is halogen, 0 ≦ g ≦ 4) magnesium which is obtained by catalytic reaction of the titanium compound in a liquid state represented by, aluminum, halogen and A titanium-supported titanium contact component having titanium as an essential component, and [B] an organometallic compound catalyst component of Group I of Tables I to III, wherein at least 5 g of olefin per milligram atom of titanium is contained in the titanium catalyst component. A catalyst for the production of an ethylene polymer, which is prepolymerized.