JP6914747B2 - Method for producing modified solid titanium catalyst component, method for producing ethylene-based polymer particles, and ethylene-based polymer particles - Google Patents

Description

The present invention relates to a method for producing a modified solid titanium catalyst component, a method for producing ethylene-based polymer particles, and ethylene-based polymer particles.

As a catalyst for olefin polymerization, many studies have been conducted on catalysts containing a solid titanium catalyst component and an organometallic compound catalyst component, and many publications have been disclosed.

As such a catalyst for olefin polymerization, Patent Document 1 discloses a catalyst containing a solid titanium catalyst component and an organometallic compound catalyst component prepared by a specific method as a catalyst having excellent polymerization activity and the like.

Japanese Unexamined Patent Publication No. 56-811

When an olefin containing ethylene is polymerized using a conventionally known catalyst such as the catalyst for olefin polymerization described in Patent Document 1, the obtained ethylene-based polymer particles are said to be prone to aggregation and have a low bulk density. There was room for improvement in that respect.

The present invention has been made in view of the above problems, and is a method for producing a modified solid titanium catalyst component capable of suppressing aggregation and easily obtaining ethylene-based polymer particles having a large bulk density, and an ethylene-based polymer. An object of the present invention is to provide a method for producing particles.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved according to the following configuration example, and has completed the present invention.
A configuration example of the present invention is as follows.

[1] Including a step of contacting a polar substance with a solid titanium catalyst component containing magnesium, halogen, titanium and an electron donor.
The amount of the polar substance used is 0.5 to 10 mol with respect to 1 mol of titanium contained in the solid titanium catalyst component.
A method for producing a modified solid titanium catalyst component.

[2] The production method according to [1], wherein the average particle size of the solid titanium catalyst component is 1 μm or less.

[3] The solid titanium catalyst component is
A method comprising a step of forming a solid product by contacting a magnesium compound having no reducing ability in a liquid state and a titanium compound in a liquid state in a liquid state, and satisfying the following (I) or (II). The production method according to [1] or [2], which is a component obtained in 1.
(I) The contact is carried out in the coexistence of an electron donor having no active hydrogen. (II) After the step, the obtained solid product is brought into contact with an electron donor having no active hydrogen.

[4] The production according to any one of [1] to [3], wherein the polar substance is at least one compound selected from the group consisting of alcohols, esters, amines, aldehydes, ketones, carboxylic acids and ethers. Method.
[5] The production method according to any one of [1] to [4], wherein the polar substance is at least one compound selected from the group consisting of ethanol and ethyl benzoate.

[6] The modified solid titanium catalyst component obtained by the production method according to any one of [1] to [5], and
The step of polymerizing an olefin containing ethylene in the presence of a catalyst for olefin polymerization containing an organometallic compound catalyst component containing a metal element selected from Group I to Group III of the Periodic Table is included.
A method for producing ethylene-based polymer particles having an average particle size of 8 to 35 μm.

[7] The production method according to [6], wherein the ethylene-based polymer particles further satisfy the following requirements (A) to (C).
Requirement (A): Bulk density is 210-450 g / L
Requirement (B): The proportion of particles having a circularity of 0.8 or more analyzed by a particle shape image analyzer is 19% or more Requirement (C): The ultimate viscosity "η" is 8 to 25 dl / g.

[8] The average particle size is 8 to 35 μm.
The bulk density is 210-450 g / L,
The proportion of particles having a circularity of 0.8 or more analyzed by a particle shape image analyzer is 19% or more.
The ultimate viscosity "η" is 8 to 25 dl / g,
Ethylene-based polymer particles.

According to the present invention, agglomeration is suppressed, and ethylene-based polymer particles having a large bulk density can be easily produced.

≪Manufacturing method of modified solid titanium catalyst component≫
The method for producing a modified solid titanium catalyst component according to the present invention (hereinafter, also referred to as "method for producing the present catalyst component") comprises a polar substance and a solid titanium catalyst component containing magnesium, halogen, titanium and an electron donor. Including the step of contacting (hereinafter, also referred to as "step A").
This is a method in which the amount of the polar substance used is 0.5 to 10 mol with respect to 1 mol of titanium contained in the solid titanium catalyst component.

The method for producing the present catalyst component is characterized in that the solid titanium catalyst component is modified with a polar substance, and this modification treatment is also a method for adjusting or reducing the olefin polymerization activity of the solid titanium catalyst component.
The catalyst used for the polymerization of olefins is usually required to have high polymerization activity. However, in order to produce ethylene-based polymer particles (average particle size: about 8 to 35 μm), it is necessary to use a catalyst component having a small average particle size (average particle size: about 1 μm or less). It was found that the catalyst component having a small particle size tends to have too high catalytic activity because the specific surface area is large, and the obtained ethylene-based polymer tends to aggregate. As a result of diligent studies by the present inventor, a solid titanium catalyst component having optimum polymerization activity can be obtained while adjusting or reducing the polymerization activity by modifying the solid titanium catalyst component with a predetermined amount of a polar substance. It has been found that by using the solid titanium catalyst component, aggregation is suppressed and ethylene-based polymer particles having a large bulk density can be easily produced.
The invention for reducing the activity of a catalyst, which is required to have high polymerization activity, is a novel method completely different from the conventional method because it is based on an idea which a person skilled in the art has not considered in the past.

<Step A>
The step A is not particularly limited as long as it is a step of bringing the polar substance into contact with the solid titanium catalyst component containing magnesium, halogen, titanium and an electron donor, but is a step of bringing them into contact with each other in an inert medium. Is preferable.
The polar substance used in the step A may be one kind or two or more kinds.
The solid titanium catalyst component used in the step A may be two or more kinds, but is usually one kind.

The amount of the polar substance used in the step A may be appropriately adjusted according to the type of the polar substance used, and the proportion of the obtained ethylene-based polymer particles having a circularity of 0.8 or more is in the following range. However, the amount of the polar substance used with respect to 1 mol of titanium contained in the solid titanium catalyst component is 0.5 to 10 mol, preferably 0.6 to 9 mol, more preferably 0. .7-8 mol.
When the amount of the polar substance used is within the above range, a modified solid titanium catalyst component having optimum polymerization activity can be obtained, and aggregation occurs in the polymerization of an olefin containing ethylene using the modified solid titanium catalyst component. Is suppressed, and ethylene-based polymer particles having a large bulk density can be easily produced.

The inert medium is a liquid other than the polar substance, and preferably an inert hydrocarbon is used. Examples of the inert medium include decane, dodecane, octane, heptane, hexane, kerosene and the like, and among these, decane is preferable. As the inert medium, one type may be used, or two or more types may be used.
The amount of the inert medium used in the step A is such that the concentration of the solid titanium catalyst component is preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight.

The contact time in the step A may be appropriately selected depending on the polar substance used, and is not particularly limited, but is preferably 5 minutes to 10 hours, more preferably 30 minutes to 5 hours.

Step A may be carried out at room temperature or under heating, but is preferably at room temperature. Examples of the temperature when the step A is performed under heating include 30 to 50 ° C.

The contact atmosphere in the step A may be appropriately selected depending on the solid titanium catalyst component to be used, and may be in the atmosphere, but is preferably in the atmosphere of an inert gas such as nitrogen.

In the method for producing the present catalyst component, it is preferable to wash the obtained modified solid titanium catalyst component after performing step A. Examples of the cleaning liquid used for this cleaning include the above-mentioned inert medium.

[Polar substance]
The polar substance is not particularly limited, and examples thereof include compounds capable of adjusting or reducing the catalytic activity of the solid titanium catalyst component, particularly the olefin polymerization activity, and examples of such substances include alcohols, esters, amines, and the like. Alkenes, ketones, carboxylic acids, ethers and the like are preferred.
The amount used for modifying the solid titanium catalyst component is appropriately adjusted depending on the performance of the polar substance.

Among these, alcohols and esters are preferable from the viewpoint of not excessively reducing the catalytic activity of the solid titanium catalyst component, particularly the olefin polymerization activity, and are obtained when the olefin is polymerized using the modified solid titanium catalyst component. Alcohol is preferable from the viewpoint of being able to further suppress the aggregation of the polymer particles to be obtained, and ester is preferable from the viewpoint of polymerization activity when polymerizing an olefin using a modified solid titanium catalyst component. Alcohol is more preferred in terms of balance.

Examples of the alcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, 2-ethylhexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol and isopropyl. Examples thereof include alcohols having 1 to 18 carbon atoms such as benzyl alcohol; and halogen-containing alcohols having 1 to 18 carbon atoms such as trichloromethanol, trichloroethanol and trichlorohexanol.
Among these, a modified solid titanium catalyst component having optimum polymerization activity can be obtained, and in the polymerization of an olefin containing ethylene using the modified solid titanium catalyst component, aggregation is suppressed and ethylene having a high bulk density is obtained. Ethanol, for example, can be preferably used from the viewpoint that the system polymer particles can be easily produced.

Examples of the ester include methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate. , Ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl tolulate, Amil toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, dimethyl carbonate, ethyl carbonate, etc. Examples include organic acid esters.
Among these, a modified solid titanium catalyst component having optimum polymerization activity can be obtained, and in the polymerization of an olefin containing ethylene using the modified solid titanium catalyst component, aggregation is suppressed and ethylene having a large bulk density is obtained. Ethylene benzoate can be preferably used, for example, from the viewpoint that the system polymer particles can be easily produced.

Examples of the amine include methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, tributylamine, tribenzylamine, tetramethylenediamine, hexamethylenediamine, piperidine, aniline, pyridine and the like.
Examples of the aldehyde include aldehydes having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, and naphthaldehyde.
Examples of the ketone include ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, benzoquinone, and cyclohexanone.
Examples of the carboxylic acid include formic acid, acetic acid, propionic acid, cyclohexanecarboxylic acid, benzoic acid, and terephthalic acid.
Examples of the ether include diethyl ether, ethyl methyl ether, cyclic ether such as ethylene oxide and tetrahydrofuran, and polyether such as polyethylene glycol and polypropylene glycol.

[Solid titanium catalyst component]
The solid titanium catalyst component is not particularly limited as long as magnesium, halogen, titanium and an electron donor are included, but the average particle size is 1 μm or less from the viewpoint that the effect of performing the step A is more exhibited. It is preferably a catalyst component.
In order to obtain ethylene-based polymer particles having an average particle size of 8 to 35 μm, the catalyst component having the average particle size is used, but when a conventional catalyst component having such an average particle size is used, the obtained ethylene is used. Since the agglomeration of the system polymer is remarkable, the effect of the production method of this catalyst component is remarkably exhibited.

The average particle size of the solid titanium catalyst component is preferably 1 μm or less, more preferably 0.2 to 1 μm, and particularly preferably 0.3 to 0.9 μm.
By using a catalyst component having such an average particle size, ethylene-based polymer particles having an average particle size of 8 to 35 μm can be easily obtained, and according to the method for producing the present catalyst component, such particles can be easily obtained. Even if a catalyst component having an average particle size is used, aggregation is suppressed, and ethylene-based polymer particles having a large bulk density can be easily produced.

The solid titanium catalyst component includes a magnesium compound having no reducing ability in a liquid state (hereinafter, also referred to as “liquid Mg compound”) and a liquid from the viewpoint that the effect of performing the step A is more exhibited. The following (I) includes a step of forming a solid product (hereinafter, also referred to as “step a”) by contacting a titanium compound in a state (hereinafter, also referred to as “liquid Ti compound”) in a liquid state. Alternatively, it is preferable that the component is obtained by the method satisfying (II).
(I) The contact is carried out in the coexistence of an electron donor having no active hydrogen. (II) After the step, the obtained solid product is brought into contact with an electron donor having no active hydrogen.

The solid titanium catalyst component may be a component obtained by the method of performing both (I) and (II). According to this method, the particle size and the shape can be adjusted according to the above (I), and the catalyst performance can be finely adjusted according to the above (II).

<Magnesium compound that does not have reducing ability in the liquid state>
Examples of the magnesium compound having no reducing ability (hereinafter, also referred to as “Mg compound”) include magnesium compounds having no magnesium-carbon bond or magnesium-hydrogen bond, and are derived from magnesium compounds having reducing ability. It may be a compound.
The liquid Mg compound used in the step a may be one kind or two or more kinds.

Examples of the Mg compound include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; and alkoxymagnesium such as methoxymagnesium chloride, magnesium ethoxychloride, magnesium isopropoxychloride, magnesium butoxychloride, and magnesium octoxychloride. Halide; Allyloxymagnesium such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; Alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium and Octoxymagnesium; Allyloxymagnesium such as phenoxymagnesium and dimethylphenoxymagnesium; Magnesium laurate , Magnesium carboxylate such as magnesium stearate and the like.

The Mg compound may be a complex compound with another metal, a compound compound, or a mixture with another metal compound.

As the Mg compound, halogen-containing magnesium compounds, particularly alkoxy magnesium chloride and allyloxymagnesium chloride are preferable.

As the liquid Mg compound, a solution in which the magnesium compound having no reducing ability is dissolved in a soluble hydrocarbon solvent, an electron donor or a mixture thereof is preferable.
The hydrocarbon solvent and the electron donor may be one type or two or more types, respectively.
Among these, when an electron donor is used, it is generally necessary to maintain the temperature at a high temperature. Therefore, from the viewpoint of preparing the solid titanium catalyst component, a solution dissolved in a hydrocarbon solvent is preferable. By using the solution, a high-performance solid titanium catalyst component can be easily obtained.

Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, tetradecane and kerosene; and alicyclics such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane and cyclohexene. Group hydrocarbons; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, and simene; halogenated hydrocarbons such as dichloroethane, dichloropropane, trichloroethylene, carbon tetrachloride, and chlorobenzene can be mentioned.

The method for preparing a liquid Mg compound in which the Mg compound is dissolved in a hydrocarbon solvent varies depending on the type of the Mg compound and the solvent, but a method of simply mixing the two, a method of mixing and heating the two, and a method of dissolving the Mg compound can be dissolved. Heating as needed in the presence of various electron donors, such as alcohols, aldehydes, amines (primary or secondary), carboxylic acids, mixtures thereof, mixtures of these with other electron donors, etc. There is a way to do it.

Specifically, when a halogen-containing magnesium compound is dissolved in a hydrocarbon solvent using alcohol, the halogen-containing magnesium compound 1 is preferable, although it varies depending on the type and amount of the hydrocarbon solvent used, the type of Mg compound, and the like. Alcohol is used in an amount of about 1 mol or more, preferably about 1 to 20 mol, particularly preferably about 1.5 to 12 mol, per mol.

When aliphatic hydrocarbons and / or alicyclic hydrocarbons are used as the hydrocarbon solvent, alcohol is used in the above amount, and in particular, alcohol having 6 or more carbon atoms is added to 1 mol of the halogen-containing magnesium compound. On the other hand, when about 1 mol or more, preferably about 1.5 mol or more is used, the halogen-containing magnesium compound can be solubilized even if the total amount of alcohol used is small, and the solid titanium catalyst component having high activity can be solubilized. Is preferable in that In this case, for example, if only alcohol having 5 or less carbon atoms is used, about 20 mol or more of alcohol is required for 1 mol of the halogen-containing magnesium compound, and the catalytic activity of the obtained solid titanium catalyst component also has 6 carbon atoms. It tends to decrease as compared with the case of using the above alcohol.
On the other hand, when aromatic hydrocarbons are used as the hydrocarbon solvent, the halogen-containing magnesium compound can be solubilized by the amount of the alcohol used regardless of the type of alcohol.

The contact between the halogen-containing magnesium compound and the alcohol is preferably carried out in a hydrocarbon solvent, and the temperature at the time of the contact is usually room temperature or higher, and depending on the type of the solvent, about 65 ° C. or higher, preferably about 80. The temperature is ~ 300 ° C., more preferably about 100 to 200 ° C., and the contact time is preferably 15 minutes to 5 hours, more preferably 30 minutes to 2 hours.

Suitable alcohols having 6 or more carbon atoms include 2-methylpentanol, 2-ethylbutanol, n-heptanol, n-octanol, 2-ethylhexanol, decanol, dodecanol, tetradecyl alcohol, undecenol, and oleyl alcohol. , Aliper alcohols such as stearyl alcohols; alicyclic alcohols such as cyclohexanol and methylcyclohexanol; aromatics such as benzyl alcohol, methylbenzyl alcohol, isopropylbenzyl alcohol, α-methylbenzyl alcohol, α, α-dimethylbenzyl alcohol Alcohols; examples thereof include aliphatic alcohols containing an alkoxy group such as n-butyl cellosolve and 1-butoxy-2-propanol.

Examples of the alcohol having 5 or less carbon atoms include methanol, ethanol, propanol, butanol, ethylene glycol, methyl carbitol and the like.

The aldehyde is preferably an aldehyde having 7 or more carbon atoms, and examples thereof include capryl aldehyde, 2-ethylhexyl aldehyde, and undecyl aldehyde.

The amine is preferably an amine having 6 or more carbon atoms, and examples thereof include heptyl amine, octyl amine, nonyl amine, decyl amine, lauryl amine, and 2-ethylhexyl amine.

The carboxylic acid is preferably an organic carboxylic acid having 7 or more carbon atoms, and examples thereof include caprylic acid, 2-ethylhexanoic acid, undecylenic acid, undecanoic acid, and nonyric acid.

Examples of the other electron donor include organic acid esters, acid halides, acid amides, organic acid anhydrides, phenols, ethers, ketones, tertiary amines, phosphite esters, phosphoric acid esters, phosphate amides, and nitriles. Examples thereof include isocyanates, and more specifically, compounds exemplified as the following electron donors having no active hydrogen.

The hydrocarbon solvent solution of the Mg compound can also be prepared by dissolving another magnesium compound or magnesium metal that can be the Mg compound in the hydrocarbon solvent while changing to the Mg compound.
Specifically, for example, a magnesium compound having an alkyl group, an alkoxy group, an allyloxy group, an acyl group, an amino group, a hydroxyl group or the like in a hydrocarbon solvent in which the alcohol, amine, aldehyde, carboxylic acid or the like is dissolved, magnesium oxide, etc. The Mg compound is carbonized by dissolving or suspending a magnesium metal or the like and producing a halogen-containing magnesium compound having no reducing ability while halogenating with a halogenating agent such as hydrogen halide, silicon halide or halogen. Examples thereof include a method of preparing a hydrogen solvent solution.

Further, a Grignard reagent, a dialkylmagnesium, a magnesium halide or a complex compound of these and another organic metal compound, for example, a magnesium compound having a reducing ability represented by the following formula (1) can be used as an alcohol, a ketone, an ester, an ether, etc. It can also be treated with a compound capable of extinguishing the reducing ability such as acid halide, silanol, and siloxane, and solubilized in a hydrocarbon solvent after or while preparing a magnesium compound having no reducing ability.

^{_{M a Mg b R 1 p R}} 2 q X r Y s ··· (1)
[In the formula, M is an aluminum, zinc, boron or beryllium atom, R ¹ and R ² are independently hydrocarbon groups, and X and Y are independently, OR ³ , OSiR ⁴ R ⁵ R ⁶ , NR ⁷ A group represented by R ⁸ or SR ^{9 , R 3 to} R ⁸ are independently hydrogen atoms or hydrocarbon groups, and R ⁹ is a hydrocarbon group, a> 0, b> 0. , P ≧ 0, q ≧ 0, r ≧ 0, s ≧ 0, b / a ≧ 0.5, p + q + r + s = ma + 2b (m is the valence of M), 0 ≦ (r + s) / (a + b) <1.0 Meet. ]

In the step a, the use of the Mg compound is indispensable, but a magnesium compound having a reducing ability may be used. However, in the preparation of the solid titanium catalyst component, the use of a magnesium compound having a large amount of reducing ability tends to be unfavorable.

<Titanium compound in liquid state>
As the titanium compound (hereinafter, also referred to as “Ti compound”), a tetravalent titanium compound represented by the following formula (2) is preferable.
The liquid Ti compound used in the step a may be one kind or two or more kinds.
Ti (OR) _g X _4-g・ ・ ・ (2)
[R is an independent hydrocarbon group, X is an independent halogen atom, and g is 0-4. ]

More specifically, titanium halides such as _{TiCl 4} , TiBr ₄ , TiI _{4 ; Ti (OCH 3} ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (On-C ₄ H ₉ ) Cl ₃ , Ti (OC ₂ H ₅ ) Br ₃ , Ti (Oiso-C ₄ H ₉ ) Cl ₃ and other trihalogenated alkoxytitanium; Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Dihalogenated dialkoxytitanium such as Ti (On-C ₄ H ₉ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Br _{2 ; Ti (OCH 3} ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Cl, Ti (On-C ₄ H ₉ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Br and other monohalogenated trialkoxytitanium; Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C) ₄ H ₉ ) _{Tetraalkoxytitanium} such as 4; Examples thereof include a mixture of these titanium compounds and other metal compounds such as aluminum compounds and silicon compounds.
Among these, a halogen-containing titanium compound is preferable, titanium tetrahalogenated is more preferable, and titanium tetrachloride is particularly preferable.

The liquid Ti compound may be the liquid Ti compound or a mixture thereof. Further, it may be a solution in which the Ti compound is dissolved in a solvent or the like similar to the hydrocarbon solvent described in the column of the liquid Mg compound.

<Electronic donor without active hydrogen>
Examples of the electron donor having no active hydrogen include organic acid esters, acid halides, organic acid anhydrides, ethers, aldehydes, ketones, tertiary amines, phosphite esters, phosphoric acid esters, phosphoric acid amides, and acids. Examples include amide and nitrile.
The electron donor having no active hydrogen used in the preparation of the solid titanium catalyst component may be one kind or two or more kinds.

Specifically, ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, cyclohexanone, and benzoquinone; carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, and naphthaldehyde. 2 to 15 aldehydes; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate , Ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl tolulate, Organic acid esters with 2 to 18 carbon atoms such as amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, ethylene carbonate; Acid halides with 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride, and anizoic acid chloride; 2 to 20 carbon atoms such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, anisole, and diphenyl ether. Ethers; acid amides such as N, N-dimethylamide acetate, N, N-diethylamide benzoic acid, N, N-dimethylamide toluic acid; trimethylamine, triethylamine, tributylamine, tribenzylamine, tetramethylethylenediamine, etc. Tertiary amines; nitriles such as acetonitrile, benzonitrile, tolnitrile and the like can be mentioned.
Of these, organic acid esters, especially aromatic carboxylic acid esters, are preferred.

The electron donors that do not have active hydrogen do not necessarily have to use these electron donors as starting materials, and can be generated in the process of preparing the solid titanium catalyst component.
Further, the electron donor having no active hydrogen can also be used in the form of an addition compound or a complex compound with another compound.

<Requirement (I)>
In the step a, the step of bringing the liquid Mg compound and the liquid Ti compound into contact with each other in a liquid state may be carried out in the coexistence of an electron donor having no active hydrogen.
In this case, when the liquid Mg compound and / or the liquid Ti compound itself contains an electron donor that does not have active hydrogen, it is necessary to newly add an electron donor that does not have active hydrogen at the time of the contact. However, even if the electron donor having no active hydrogen is added in advance to the liquid Mg compound and / or the liquid Ti compound, and the electron donor having no active hydrogen is further added, the contact is performed. good.
As the electron donor, not only when the electron donor itself which does not have active hydrogen is used, but also when a compound which can be an electron donor which does not have active hydrogen is used and an electron donation which does not have active hydrogen is carried out by a reaction. You may generate a body.

When preparing a liquid Ti compound containing an electron donor that does not have active hydrogen, a free titanium compound that does not form a complex compound with the electron donor that does not have active hydrogen should be present in the liquid Ti compound. It is preferable to use a large amount of Ti compound.

Specifically, the amount of the Ti compound used is preferably more than 1 mol, preferably 5 mol or more, with respect to 1 mol of the electron donor having no active hydrogen.
The amount of the Ti compound in the liquid Ti compound is preferably an amount capable of forming a solid titanium catalyst component in contact between the liquid Mg compound and the liquid Ti compound without performing a special precipitation step.

The amount of the liquid Ti compound used when contacting the liquid Mg compound and the liquid Ti compound is such that the amount of the Ti compound in the liquid Ti compound is preferably about 1 mol or more with respect to 1 mol of the Mg compound in the liquid Mg compound. It is more preferably about 3 to 200 mol, and particularly preferably about 4 to 100 mol.

The amount of the liquid Ti compound used in the preparation of the solid titanium catalyst component is preferably about 1 mol, with respect to 1 mol of the electron donor having no active hydrogen. The amount exceeds, more preferably 5 mol or more.

The amount of the electron donor that does not have active hydrogen is preferably about 0.01 to 10 mol, more preferably about 0.01 to 1 mol, and particularly preferably about, per 1 mol of the Mg compound in the liquid Mg compound. It is 0.1 to 0.5 mol.
Even if a large amount of electron donors that do not have active hydrogen are used, a high-performance solid titanium catalyst component tends to be obtained by adjusting the amount of the Ti compound used in the liquid Ti compound, but it is easy. The amount of the electron donor that does not have active hydrogen is preferably in the above range from the viewpoint that a high-performance solid titanium catalyst component can be obtained.

As a method for bringing the liquid Mg compound and the liquid Ti compound into contact with each other, any method of mixing them can be adopted.
When the liquid Mg compound and the liquid Ti compound are brought into contact with each other, they are mixed at a sufficiently low temperature so that the solid product is not rapidly produced by these contacts, and the temperature is raised to gradually raise the solid product. Is preferred. According to this method, a granular or spherical solid titanium catalyst component having a relatively large particle size tends to be obtained. Further, by allowing an appropriate amount of an electron donor having no active hydrogen to be present at the time of this contact, a solid titanium catalyst component having a narrower particle size distribution and being granular or spherical can be obtained. When a polymer is produced by slurry polymerization using the component obtained by modifying the solid titanium catalyst component thus obtained in the above step A, it is granular or spherical, has a narrow particle size distribution, has a large bulk density, and is fluid. A polymer having excellent properties can be easily obtained.
Here, the term “granular” refers to granules in which fine powders are aggregated when the particles are viewed in an enlarged photograph.

Examples of the contact temperature when the liquid Mg compound and the liquid Ti compound are brought into contact with each other include about −70 to + 200 ° C.
The temperature of the liquid Mg compound and the temperature of the liquid Ti compound at the time of contact may be different.
Generally, in order to obtain the solid titanium catalyst component having a preferable shape of granules or spheres and having high performance, as described above, a magnesium compound having no reducing ability in a liquid state and a titanium compound in a liquid state It is often preferable not to adopt a very high temperature as the contact temperature at the time of contact with, and the contact temperature is preferably about −70 to + 50 ° C.
If the contact temperature is low, precipitation of solid products may not be observed. In this case, the temperature is raised, preferably about 50 to 150 ° C. for reaction, or for a long time. It is preferable that the solid product is precipitated by the contact with the above.

The obtained solid product is preferably a liquid Ti compound, more preferably titanium tetrachloride, and is preferably washed at least once at about 50 to 150 ° C. Then, it is usually used for olefin polymerization by washing it thoroughly with a hydrocarbon.

The method for preparing the solid titanium catalyst component satisfying the requirement (I) is preferable because it is easy to operate and a high-performance solid titanium catalyst component can be easily obtained.

<Requirement (II)>
In the method for preparing the solid titanium catalyst component, after the step a, the solid product obtained by the contact may be brought into contact with an electron donor having no active hydrogen.
As a method for satisfying this requirement (II), first, a liquid Mg compound and a liquid Ti compound are brought into contact with each other in the same amount and conditions as those described in the column of the requirement (I) to obtain a solid product. After obtaining a suspension containing the mixture, an electron donor having no active hydrogen is added to the suspension, and the reaction is preferably carried out at a temperature of, for example, about 0 to 150 ° C.
The amount of the electron donor having no active hydrogen added here is preferably the same as the amount described in the column of the requirement (I).

The product obtained by adding an electron donor having no active hydrogen is preferably a titanium compound in a liquid state, more preferably titanium tetrachloride, as in the above requirement (I), at about 50 to 150 ° C. It is desirable to wash at least once. Then, it is usually used for olefin polymerization by washing it thoroughly with a hydrocarbon.

<Composition of solid titanium catalyst component, etc.>
As for the composition of the solid titanium catalyst component, magnesium / titanium (atomic ratio) is usually about 2 to 100, preferably about 4 to 50, more preferably about 5 to 30, and halogen / titanium (atomic ratio). However, it is usually about 4 to 100, preferably about 5 to 90, more preferably about 8 to 50, and the electron donor / titanium (molar ratio) is usually about 0.01 to 100, preferably about 0.2. It is 10, more preferably about 0.4 to 6.

The shape of the solid titanium catalyst component is not particularly limited, but is usually granular or granular.

≪Production method of ethylene polymer particles≫
The method for producing ethylene-based polymer particles having an average particle size of 8 to 35 μm according to the present invention (hereinafter, also referred to as “method for producing the present polymer particles”) is described.
With the modified solid titanium catalyst component,
The step of polymerizing an olefin containing ethylene in the presence of a catalyst for olefin polymerization containing an organometallic compound catalyst component containing a metal element selected from Group I to Group III of the Periodic Table is included.

The modified solid titanium catalyst component used in the method for producing the present polymer particles may be one kind, two or more kinds, and the organometallic compound catalyst component may be one kind or two or more kinds.

<Organometallic compound catalyst component>
As the organometallic compound catalyst component containing a metal element selected from Group I to Group III of the Periodic Table, the organoaluminum compound (b1) having at least one Al-carbon bond in the molecule (example: the following formula (example) Organoaluminium compound represented by 3); Complex compound of Group I metal of Periodic Table Group I represented by the following formula (4) and aluminum (b2); Compound represented by the following formula (5) (b3) And so on.

R ¹ _m Al (OR ² ) _n H _p X _q・ ・ ・ (3)
[In the formula (3), R ¹ and R ² are independently hydrocarbon groups, preferably hydrocarbon groups having 1 to 15 carbon atoms, more preferably hydrocarbon groups having 1 to 4 carbon atoms, and X is It is a halogen atom, and m, n, p and q satisfy 0 <m ≦ 3, 0 ≦ n <3, 0 ≦ p <3, 0 ≦ q <3, m + n + p + q = 3, respectively. ]

M ¹ Al (OR ¹ ) ₄ ... (4)
[In the formula (4), M ¹ is Li, Na or K, and R ¹ is synonymous with ^{R 1 in the} formula (3). ]

R ¹ R ³ M ² ... (5)
[In the formula (5), R ^{1 is synonymous with R 1 of the} formula (3), and R ^{3 is R 1 of the} formula (3) or a halogen atom, preferably of the formula (3). R ¹ and M ² are Mg, Zn or Cd. ]

Specific examples of the compound (b1) include compounds represented by the following (3-1) to (3-4).

R ¹ _m Al (OR ² ) _3-m ... (3-1)
[In the formula (3-1), R ¹ , R ² and m are independently ^{synonymous with R 1} , R ² and m in the formula (3), and m is preferably 1.5 ≦ m ≦. It is 3. ]

R ¹ _m AlX _3-m・ ・ ・ (3-2)
[In the formula (3-1), R ^{1 , X and m are independently synonymous with R 1} , X and m in the above formula (3), and m is preferably 0 <m <3. ]

R ¹ _m AlH _3-m・ ・ ・ (3-3)
[In the formula (3-3), R ¹ and m are independently ^{synonymous with R 1} and m in the formula (3), and m is preferably 2 ≦ m <3. ]

R ¹ _m Al (OR ² ) _n X _q・ ・ ・ (3-4)
[In Eq. (3-4), R ¹ , R ² , X, m, n and q are independently ^{synonymous with R 1} , R ² , X, m, n and q in Eq. (3). , M + n + q = 3. ]

More specifically, the compound (b1) includes attrialkylaluminum such as triethylaluminum and tributylaluminum; trialkenylaluminum such as triisopropenylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide; ethyl. Alkylaluminum sesquialkoxides such as aluminum sesquiethoxydo, butylaluminum sesquibutoxide, partially alkoxylated alkylaluminum with an average composition represented by ^{R 1} _2.5 Al (OR ² ) _{0.5, etc .; diethylaluminum chloride, dibutylaluminum} Dialkylaluminum halides such as chloride and diethylaluminum bromide; Alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibramide; Dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; Alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride; Examples thereof include alkylaluminum that has been converted and halogenated.

Specific examples of the compound (b2) include LiAl (O ₂ H ₅ ) ₄ , LiAl (O ₇ H ₁₅ ) _{4, and the} like.

Specific examples of the compound (b3) include dialkylzinc such as diethylzinc; dialkylmagnesium such as diethylmagnesium; alkylmagnesium halides such as ethylmagnesium chloride.

As the organometallic compound catalyst component, trialkylaluminum, alkylaluminum halide, a mixture thereof and the like are preferable.

<Olefin>
The olefin polymerized by the method for producing the polymer particles is not particularly limited as long as it contains ethylene, and is an α-olefin such as propylene, 1-butene, 4-methyl-1-pentene, 1-octene; conjugated diene or non-conjugated An unsaturated compound such as diene may be used.
The α-olefin and the unsaturated compound may be one kind or two or more kinds, respectively.

<Polymerization method / conditions>
The polymerization may be a homopolymerization of ethylene, a random copolymerization of ethylene and another monomer, or a block copolymerization. It is preferable that the ethylene is substantially homopolymerized.
The polymerization method may be any conventionally known method such as a liquid phase method or a gas phase method. Liquid phase polymerization is preferred. In particular, suspension polymerization of the liquid phase is preferable. Further, the polymerization may be carried out by any method of batch type, anti-continuous type and continuous type, and may be carried out in two or more stages having different reaction conditions.

When the polymerization is carried out in the liquid phase, it is preferable to use an inert solvent such as hexane, heptane, decane or kerosene as the reaction medium, but the olefin itself may be used as the reaction medium.

In the case of liquid phase polymerization, the modified solid titanium catalyst component is converted into titanium atoms to be about 0.0001 to 1.0 mmol per 1 L of the liquid phase, with respect to 1 mol of titanium atoms in the modified solid titanium catalyst component. It is preferable to use the modified solid titanium catalyst component and the organic metal compound catalyst component in an amount such that the amount of metal atoms in the organic metal compound catalyst component is about 1 to 2000 mol, preferably about 5 to 500 mol.

A molecular weight modifier such as hydrogen may be used in the polymerization.

The polymerization temperature of the polymerization is preferably about 20 to 200 ° C., more preferably about 50 to 180 ° C., and the polymerization pressure is preferably about normal pressure to 100 kg / cm 2, more preferably about ^{2 to 50 kg / cm.} It is cm ^2.

≪Ethylene polymer particles≫
The ethylene-based polymer particles according to the present invention (hereinafter, also referred to as “the present particles”) are
-The average particle size is 8 to 35 μm.
-The bulk density is 210-450 g / L,
-The proportion of particles with a circularity of 0.8 or more analyzed by a particle shape image analyzer is 19% or more.
-The ultimate viscosity "η" is 8 to 25 dl / g.
According to the method for producing the present polymer particles, such present particles can be easily produced.

The average particle size of the particles is preferably 10 to 30 μm, more preferably 15 to 28 μm.
When the average particle size is within the above range, it is easy to add the particles to rubber, engineering plastic, or the like, and by adding the particles, the slidability of rubber or engineering plastic can be improved.

The bulk density of the particles is preferably 215 to 440 g / L, more preferably 220 to 420 g / L.
When the bulk density is within the above range, when the particles are used for applications such as a sintered filter, a filter having a desired strength can be easily obtained.

The ultimate viscosity [η] of the particles is preferably 8 to 20 dl / g, more preferably 9 to 18 dl / g.
When the ultimate viscosity is in the above range, it is possible to impart abrasion resistance, impact resistance, chemical resistance, high strength (high stretchability) and the like to the molded product obtained by using the present particles.

The average molecular weight of the particles is preferably 920,000 to 3.3 million, more preferably 1 million to 2.9 million.
When the average molecular weight is within the above range, it is possible to impart abrasion resistance, impact resistance, chemical resistance, high strength (high stretchability) and the like to the molded product obtained by using the present particles.
The value of the average molecular weight is a value converted from [η] by the ASTM D4020 method.

The proportion of the particles having a circularity of 0.8 or more analyzed by the particle shape image analyzer is preferably 19% or more, more preferably 19 to 60%, and particularly preferably 20 to 55%.
The present particles having a circularity of 0.8 or more in the above range can be said to be particles in which aggregation is suppressed, and can be suitably used for desired applications.

The equivalent circle diameter of the particles having a circularity of 0.8 or more analyzed by the particle shape image analyzer is preferably 15 to 30 μm, more preferably 17 to 25 μm, and particularly preferably 18 to 23 μm.
The present particles having a circularity of 0.8 or more and having a circle-equivalent diameter in the above range can be said to be particles in which aggregation is suppressed, and can be suitably used for desired applications.

The average circle-equivalent diameter of the particles analyzed by the particle shape image analyzer is preferably 15 to 50 μm, more preferably 20 to 45 μm.
When the average circle equivalent diameter is within the above range, the slidability of the molded product obtained by adding the particles to rubber, engineering plastic, or the like can be improved.

The circularity of the particles analyzed by the particle shape image analyzer is preferably 0.61 to 0.80, more preferably 0.61 to 0.75.

These particles can be suitably used for rubber rolls for OA, engineering plastics, sintered filters, paint additives and the like.

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

[Example 1]
<Preparation of solid titanium catalyst component>
4.76 g (50 mmol) of anhydrous magnesium chloride, 25 mL of decan, and 23.2 mL (150 mmol) of 2-ethylhexyl alcohol are heated at 120 ° C. for 2 hours to obtain a uniform solution, and then 0.5 mL of ethyl benzoate is added thereto. (3.4 mmol) was added. The obtained solution was added dropwise to 200 mL (182 mmol) of titanium tetrachloride kept at 0 ° C. for 1 hour.
The mixture after dropping was heated to 80 ° C., 2.3 mL (15.6 mmol) of ethyl benzoate was added, and the mixture was kept under stirring for 2 hours, and then the solid substance was collected by filtration. The collected solid substance was suspended again in 200 mL of titanium tetrachloride, heated at 90 ° C. for 2 hours, and then the solid substance was collected by filtration, and a free titanium compound was detected in the washing liquid. The solid titanium catalytic component was obtained by thoroughly washing with purified hexane until it was exhausted and then drying.

The obtained solid titanium catalyst component is a component containing 180 mg / g-cat of magnesium, 35 mg / g-cat of titanium, 610 mg / g-cat of halogen, and 125 mg / g-cat of an electron donor in terms of atoms. there were.
The average particle size of the obtained solid titanium catalyst component calculated from SEM image analysis was 0.7 μm.

<Preparation of modified solid titanium catalyst component>
At room temperature under a nitrogen atmosphere, 196 mL of decan was added to 3.1 g of the solid titanium catalyst component obtained above. Ethanol (ethanol / titanium = 3) was added thereto so that the molar ratio of the solid titanium catalyst component to the titanium atom was 3, and the mixture was stirred for 1 hour. After stirring, 575 mL of decan was further added, and the mixture was stirred for 15 minutes to obtain a slurry. After allowing this slurry to stand for 1 hour, 575 mL of the supernatant decan was removed, and the same amount of decan was added for washing. A modified solid titanium catalyst component was prepared by repeating this washing (addition of decan, stirring for 15 minutes, allowing the slurry to stand for 1 hour, and removing the supernatant) three times.

<Preparation of catalyst for olefin polymerization>
To the modified solid titanium catalyst component obtained above, triethylaluminum was added so that aluminum / titanium = 1 (molar ratio), and ultrasonic crushing treatment (28 kW, 30 minutes) was performed with an ultrasonic cleaner. By doing so, a catalyst (slurry) for olefin polymerization was prepared.

<Manufacturing of polyethylene particles>
0.5 L of decan was charged into a SUS autoclave having an internal volume of 1.0 L sufficiently substituted with nitrogen, and the temperature inside the system was raised to 65 ° C. while stirring at a stirring speed of 150 rpm. Then, 0.5 mmol of triisobutylaluminum and the catalyst for olefin polymerization obtained above were added so as to be 0.033 mmol in terms of magnesium atoms.
Subsequently, the autoclave was sealed, the stirring speed was set to 350 rpm, the temperature was raised to 70 ° C., and then 15 mL of hydrogen was added. Subsequently, ethylene was continuously added at a flow rate of 0.24 L / min, and polymerization was carried out until the integrated flow rate of ethylene reached 90 L. After cooling, the autoclave was released and the resulting particles were collected by filtration and dried under reduced pressure at 80 ° C. overnight. As a result, 98.1 g of polyethylene particles were obtained.

[Ultimate viscosity [η]]
The obtained polyethylene particles were dissolved in decalin, and [η] of the polyethylene particles was measured in decalin at a temperature of 135 ° C. according to a conventional method. The results are shown in Table 2.

〔The bulk density〕
The bulk density of the obtained polyethylene particles was measured according to JIS K 6721. The results are shown in Table 2.

[Shape of polyethylene particles]
The obtained polyethylene particles were analyzed using PITA-3 (particle shape image analyzer, manufactured by Seishin Enterprise Co., Ltd., dispersion medium: isopropyl alcohol, measurement range: 5 to 300 μm, number of measurement particles: 1500 to 5000). The average circle equivalent diameter, circularity, and the proportion of particles having a circularity of 0.8 or more and the equivalent circle diameter of particles having a circularity of 0.8 or more were calculated.
From the results of image analysis, particles having a circularity of 0.8 or more were defined as primary particles, and this ratio was determined to be the ratio of primary particles. The results are shown in Table 3.
With respect to the obtained polyethylene particles, the average particle size of the primary particles was calculated by SEM image analysis (average number of measured particles of 300 or more). The results are shown in Table 3.

[Examples 2 to 3]
In the preparation of the modified solid titanium catalyst component, polyethylene particles were produced in the same manner as in Example 1 except that the amount of ethanol used was changed to the amount shown in Table 1 below.

[Examples 4 to 5]
In the preparation of the modified solid titanium catalyst component, ethyl benzoate was used instead of ethanol, and polyethylene particles were produced in the same manner as in Example 1 except that the amount used was changed to the amount shown in Table 1 below. ..

[Comparative Example 1]
Polyethylene particles were produced in the same manner as in Example 1 except that ethanol was not used in the preparation of the modified solid titanium catalyst component.

By denaturing the solid titanium catalyst component with a polar substance such as ethanol or ethyl benzoate, the proportion of particles with a circularity of 0.8 or more increases (decrease in aggregation) and the bulk density is increased compared to the untreated case. Has grown.
For example, polymer particles having a small bulk density and a large amount of agglomeration may cause a decrease in strength when the particles are used in an application such as a sintering filter, but according to the present invention, they are suitable for applications such as a sintering filter. The ethylene-based polymer particles that can be used in the above can be easily obtained.

The effect of reducing aggregation was higher when ethanol was used than when ethyl benzoate was used, and the polymerization activity of the modified solid titanium catalyst component was higher when ethyl benzoate was used than when ethanol was used.

Claims (10)

Including the step of contacting the polar substance with a solid titanium catalyst component containing magnesium, halogen, titanium and an electron donor.
The amount of the polar substance used is 0.5 to 10 mol with respect to 1 mol of titanium contained in the solid titanium catalyst component.
A method for producing a modified solid titanium catalyst component for producing ethylene-based polymer particles. The method for producing a modified solid titanium catalyst component according to claim 1, wherein the ethylene-based polymer particles have an average particle size of 8 to 35 μm. The production method according to claim 1 or 2 , wherein the average particle size of the solid titanium catalyst component is 1 μm or less. The solid titanium catalyst component
A method comprising the step of forming a solid product by contacting a magnesium compound having no reducing ability in a liquid state and a titanium compound in a liquid state in a liquid state, and satisfying the following (I) or (II). The production method according to any one of claims 1 to 3, which is a component obtained in 1.
(I) The contact is carried out in the coexistence of an electron donor having no active hydrogen. (II) After the step, the obtained solid product is brought into contact with an electron donor having no active hydrogen. The production method according to any one of claims 1 to 4 , wherein the polar substance is at least one compound selected from the group consisting of alcohols, esters, amines, aldehydes, ketones, carboxylic acids and ethers. The production method according to any one of claims 1 to 5 , wherein the polar substance is at least one compound selected from the group consisting of ethanol and ethyl benzoate. The production method according to any one of claims 1 to 5, wherein the polar substance is alcohol. A modified solid titanium catalyst component obtained by the production method according to any one of claims 1 to 7.
A step of polymerizing an olefin containing ethylene in the presence of a catalyst for olefin polymerization containing an organic metal compound catalyst component containing a metal element selected from Group 1, Group 2 and Group 13 of the Periodic Table.
A method for producing ethylene-based polymer particles having an average particle size of 8 to 35 μm. The production method according to claim 8, wherein the step of polymerizing the ethylene-containing olefin is a step of suspend-polymerizing the ethylene-containing olefin in a liquid phase. The production method according to claim 8 or 9 , wherein the ethylene-based polymer particles further satisfy the following requirements (A) to (C).
Requirement (A): Bulk density is 210-450 g / L
Requirement (B): The proportion of particles having a circularity of 0.8 or more analyzed by a particle shape image analyzer is 19% or more Requirement (C): The ultimate viscosity "η" is 8 to 25 dl / g.