JP7228447B2 - Method for producing solid titanium catalyst component for ethylene polymerization - Google Patents

Description

The present invention relates to a method for producing a solid titanium catalyst component for ethylene polymerization.

Ethylene polymers such as homopolyethylene and linear low-density ethylene polymer (LLDPE) have excellent transparency and mechanical strength and are widely used as films and the like. Various methods for producing such an ethylene polymer are conventionally known. It is known that an ethylene polymer can be produced with high polymerization activity by using a solid titanium catalyst containing a titanium catalyst component containing titanium, magnesium, halogen and an optional electron donor as a polymerization catalyst. (See Patent Documents 1 and 2, for example).

In the production of ethylene polymers, if ethylene can be polymerized with higher activity, not only will productivity improve, but the catalyst residue per polymer, especially the amount of halogen, will be reduced. Problems such as rust can also be eliminated. Therefore, a titanium catalyst component capable of polymerizing ethylene with higher activity is desired.

Moreover, a polymer obtained by polymerizing ethylene is usually obtained in the form of a powder, regardless of whether it is a slurry method or a gas phase method. In this case, it is desirable that the ethylene polymer has a small amount of fine powder and a narrow particle size distribution. Moreover, the ethylene polymer having excellent bulk density and particle properties has various advantages such as being able to be used as it is without being pelletized depending on the application.

Moreover, in order to obtain a film excellent in transparency and mechanical strength, a method of widening the molecular weight distribution by multistage polymerization is known. The molecular weight is usually adjusted by adding hydrogen, but the activity tends to decrease when the hydrogen content is increased to produce a low molecular weight portion. That is, a catalyst capable of adjusting the molecular weight with a small amount of hydrogen is advantageous in terms of activity even in multi-stage polymerization. Therefore, an ethylene polymerization catalyst is desired which is excellent in molecular weight controllability by hydrogen, which is called hydrogen responsiveness.

JP-A-9-328514 JP-A-10-53612

Furthermore, the content of low-molecular weight components in the obtained ethylene polymer can be reduced while maintaining the functions of conventional catalysts such as particle properties (i.e., the molecular weight distribution is relatively narrow, and stickiness when processed into a film, etc.). Catalysts with improved functionality, such as the ability to suppress In addition, it is said that a catalyst with a wide particle size distribution is difficult to produce under high polymer concentration conditions because there is a risk of clogging of pipes due to fine particles or coarse particles of the polymer produced. That is, load-up production tends to be difficult. (This risk is based on the results of the small-scale polymerization test, and depending on the polymerization conditions, it may be difficult to recognize the presence of fine powder due to aggregation due to static electricity or the like, or adhesion to other particles.) It is thought that there is a tendency to require a catalyst with a narrow particle size distribution.

According to the study of the present inventors, in the conventional method, for example, when a diether compound having a function of slightly narrowing the molecular weight distribution of the obtained ethylene polymer is used as an electron donor, the particle properties are not necessarily sufficient. I've learned that sometimes I can't. On the other hand, the inventors have found that when a specific liquid magnesium compound is used, excellent particle properties can be achieved even with a small amount or no amount of the electron donor used in contacting the liquid titanium compound in the conventional method.

Accordingly, an object of the present invention is to provide a method for producing a solid catalyst component for ethylene polymerization that has excellent particle properties and functions such as reduction of low-molecular-weight components in a well-balanced manner.
In this case, it is preferable to have the ability to polymerize ethylene with high activity, to be excellent in hydrogen responsiveness, and to produce an ethylene polymer having good particle properties.

The present inventors have studied to solve the above problems. As a result, the inventors have found that a solid titanium catalyst component for ethylene polymerization that can solve the above problems can be obtained by the following production method, and have completed the present invention.

The present invention relates to, for example, the following [1] to [7].
[1] (1) A liquid magnesium compound (A) containing a magnesium compound, an electron donor having 1 to 5 carbon atoms (a) and an electron donor having 6 to 30 carbon atoms (b), and a liquid titanium compound (C ) and the magnesium atom (Mg ) and the electron donor (B1) have a molar ratio [(B1)/(Mg)] of 0.04 or less and are brought into contact under conditions of −30 to 50° C. to obtain a contact product; and (2 ) the contact material and the electron donor (B2), and the molar ratio [(B2)/(AC)] of the magnesium atom (AC) contained in the contact material and the electron donor (B2) is 0.05 A process for producing a solid titanium catalyst component (I) for ethylene polymerization containing titanium, magnesium and halogen, comprising the step of contacting at a temperature of 85 to 135°C.

[2] The molar ratio [(a)/(b)] between the amount of the electron donor (a) used and the amount of the electron donor (b) used is less than 1, and the electron donor ( The solid for ethylene polymerization according to [1] above, wherein a), the electron donor (b), the electron donor (B1) and the electron donor (B2) are heteroatom-containing compounds other than cyclic ether compounds. A method for producing a shaped titanium catalyst component (I).

[3] The ethylene according to [1] or [2] above, wherein the electron donor (a) is an alcohol having 1 to 5 carbon atoms and the electron donor (b) is an alcohol having 6 to 12 carbon atoms. A method for producing a solid titanium catalyst component (I) for polymerization.

[4] The production of the solid titanium catalyst component (I) for ethylene polymerization according to any one of [1] to [3], wherein the electron donor (B1) and/or (B2) contains a polyether. Method.

[5] The method for producing a solid titanium catalyst component (I) for ethylene polymerization according to [4] above, wherein the electron donor (B1) and/or (B2) contains a compound represented by the following formula (b1).

［式（ｂ１）中、ｍは１～１０の整数であり、Ｒ¹¹、Ｒ¹²、Ｒ³¹～Ｒ³⁶は、それぞれ独立に、水素原子、または炭素、水素、酸素、フッ素、塩素、臭素、ヨウ素、窒素、硫黄、リン、ホウ素およびケイ素から選択される少なくとも１種の元素を有する置換基である。任意のＲ¹¹、Ｒ¹²、Ｒ³¹～Ｒ³⁶は共同してベンゼン環以外の環を形成していてもよく、主鎖中に炭素以外の原子が含まれていてもよい。］

[In the formula (b1), m is an integer of 1 to 10, and R ¹¹ , R ¹² , R ³¹ to R ³⁶ are each independently a hydrogen atom, or carbon, hydrogen, oxygen, fluorine, chlorine, bromine, A substituent having at least one element selected from iodine, nitrogen, sulfur, phosphorus, boron and silicon. Arbitrary R ¹¹ , R ¹² , R ³¹ to R ³⁶ may jointly form a ring other than a benzene ring, and may contain an atom other than carbon in the main chain. ]

[6] For ethylene polymerization comprising the solid titanium catalyst component (I) for ethylene polymerization obtained by the production method according to any one of [1] to [5] above and the organometallic compound catalyst component (II) catalyst.

[7] A method for polymerizing ethylene, comprising homopolymerizing ethylene or copolymerizing ethylene with another olefin in the presence of the ethylene polymerization catalyst described in [6] above.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the solid titanium catalyst component for ethylene polymerization which has excellent particle|grain property and functions, such as reduction of a low molecular weight component, in good balance can be provided. For example, when a diether compound or the like is used as an electron donor, the conventional method does not provide sufficient particle properties, but the present invention provides a catalyst component with good particle properties and a narrow molecular weight distribution.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated.
In the present invention, the term "polymerization" may be used to mean not only homopolymerization but also copolymerization, and the term "polymer" means not only homopolymers but also copolymers. Sometimes used in

[Method for Producing Solid Titanium Catalyst Component (I) for Ethylene Polymerization]
The method for producing the solid titanium catalyst component (I) for ethylene polymerization of the present invention comprises:
(1) a liquid magnesium compound (A) containing a magnesium compound, an electron donor having 1 to 5 carbon atoms (a), and an electron donor having 6 to 30 carbon atoms (b);
a liquid titanium compound (C),
Without using the electron donor (B1), or in the presence of the electron donor (B1) when using the electron donor (B1), the magnesium atom (Mg) contained in the liquid magnesium compound (A) and the electron donor (B1) molar ratio [(B1)/(Mg)] to the body (B1) is 0.04 or less, contacting at -30 to 50 ° C. to obtain a contact material; and (2) the contact material and the electron donor (B2), wherein the molar ratio [(B2)/(AC)] of the magnesium atom (AC) contained in the contact material and the electron donor (B2) is 0.05 to 0.19. and contacting under conditions of 85 to 135 ° C;
have

The solid titanium catalyst component (I) for ethylene polymerization obtained by the production method of the present invention (hereinafter also referred to as "titanium catalyst component (I)") contains titanium, magnesium and halogen. The titanium catalyst component (I) has excellent hydrogen responsiveness, and by using the component (I), an ethylene polymer having a slightly narrow molecular weight distribution, less generation of solvent-soluble components, and a better particle shape than conventional ethylene polymers. tend to be easier to obtain.

In the following description, the electron donor (B1) that can be used in step (1) and the electron donor (B2) that can be used in step (2) are also collectively referred to as "electron donor (B)." When the electron donor (B1) is used in step (1), the electron donor (B1) used in step (1) and the electron donor (B2) used in step (2) are They may be the same or different.
Each step will be described below. Each component used in each step will be described later.

<Step (1)>
In step (1), the liquid magnesium compound (A) and the liquid titanium compound (C) are brought into contact without using the electron donor (B1), or when the electron donor (B1) is used, the electron donor A contact product is obtained by contacting in the presence of (B1).

When the contact is performed in the presence of the electron donor (B1), the molar ratio between the magnesium atom (Mg) contained in the liquid magnesium compound (A) and the electron donor (B1) in step (1) [(B1) /(Mg)] is 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less.

From the viewpoint of the particle morphology of the solid titanium catalyst component to be obtained, it is preferred that the electron donor (B1) is not used in step (1), or even if the electron donor (B1) is used, the above molar ratio is maintained.

In the step (1), the amount of the liquid titanium compound (C) used per 1 mol of magnesium atoms (Mg) contained in the liquid magnesium compound (A) is preferably 0.1 to 100 mol, more preferably 0.5 to 80 mol. mol, more preferably 1 to 70 mol, particularly preferably 5 to 70 mol.

In step (1), the contact temperature is -30 to 50°C, preferably -25 to 45°C, more preferably -20 to 40°C. From the viewpoint of the particle morphology of the obtained solid titanium catalyst component, it is preferable to carry out the contact at the above temperature.

Examples of the method of contacting the liquid magnesium compound (A) and the liquid titanium compound (C) without using the electron donor (B1) or in the presence of the electron donor (B1) include (P-1) below. to (P-4).

(P-1) A method of contacting the liquid magnesium compound (A) and the liquid titanium compound (C) to obtain a contact product. At this time, the contact with the liquid titanium compound (C) may be carried out several times.

(P-2) A method of contacting a mixture of the liquid magnesium compound (A) and the electron donor (B1) with the liquid titanium compound (C) to obtain a contact product. At this time, the contact with the liquid titanium compound (C) may be carried out several times.

(P-3) A method of contacting the liquid magnesium compound (A) with a mixture of the electron donor (B1) and the liquid titanium compound (C) to obtain a contact product. At this time, the contact with the mixture may be performed in a plurality of times.

(P-4) A method of simultaneously contacting the liquid magnesium compound (A), the electron donor (B1) and the liquid titanium compound (C) to obtain a contact product.
When the electron donor (B1) is used, among the above methods, the method of (P-2), in particular, the method of using the liquid magnesium compound (A) and the electron donor (B1) as a premixed liquid. This is preferable from the standpoint of productivity and handling because the obtained solid titanium catalyst component has good particle properties (irregular particles and fine particles are less likely to form) and the purification process by filtration and decantation proceeds smoothly.

<Step (2)>
In step (2), the contact material obtained in step (1) and the electron donor (B2) are adjusted to the molar ratio of magnesium atoms (AC) and electron donors (B2) contained in the contact material [ (B2)/(AC)] is 0.05 to 0.19, and the contact is made under the conditions of 85 to 135°C.

The molar ratio [(B2)/(AC)] of the magnesium atom (AC) contained in the contact material in step (2) and the electron donor (B2) used in step (2) is 0.05 to 0. .19, preferably 0.06 to 0.185, more preferably 0.07 to 0.18. From the viewpoint of function expression such as reduction of low-molecular-weight components, it is preferable to use the electron donor (B2) at the above molar ratio.

The present inventors' studies have revealed that in the step (1), the particle size distribution may not be improved when a considerable amount of the specific electron donor (B1) is used. On the other hand, it was found that when the electron donor (B2) is used under the conditions of step (2), the adverse effect on the particle size distribution is suppressed, and there is a tendency to impart suitable functions such as the aforementioned molecular weight distribution.

In step (2), the contact temperature is 85 to 135°C, preferably 90 to 130°C, more preferably 95 to 125°C. Addition of the electron donor at a high temperature has less effect on the particle properties, and it is believed that the desired performance can be imparted.
In step (2), the contact with the electron donor (B2) may be performed in multiple steps.

<Titanium catalyst component (I)>
The halogen/titanium (atomic ratio) contained in the titanium catalyst component (I) of the present invention is usually 2-100, preferably 4-90. The magnesium/titanium (atomic ratio) contained in the titanium catalyst component (I) of the present invention is usually 1-100, preferably 1-50.

The molar ratio of the electron donor (B), electron donor (a) or electron donor (b) contained in the titanium catalyst component (I) of the present invention to the titanium atom (electron donor/Ti) is It is usually 0-100, preferably 0.01-10, more preferably 0.2-10. The electron donor (B) includes the electron donors (B1) and (B2) described above.
Each component used in the production method of the present invention will be described below.

<Liquid magnesium compound (A)>
The liquid magnesium compound (A) contains a magnesium compound, an electron donor (a) having 1 to 5 carbon atoms, and an electron donor (b) having 6 to 30 carbon atoms. If the liquid magnesium compound (A) contains these specific electron donors, the amount of the electron donor (aggregating agent) used in the step (1) of contacting the compound (A) with the liquid titanium compound (C) can form particles with excellent particle properties even when used in small amounts or even at zero.

A representative method of obtaining the liquid magnesium compound (A) is a method of contacting a known magnesium compound, an electron donor (a) and an electron donor (b), preferably in the presence of a liquid hydrocarbon medium, to form a liquid. Examples include:

Examples of magnesium compounds include those described in JP-A-58-83006 and JP-A-56-811. As the magnesium compound, a solvent-soluble magnesium compound is particularly preferred.

As a magnesium compound, specifically,
Magnesium halides such as magnesium chloride, magnesium bromide;
Alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride;
aryloxymagnesium halides such as phenoxymagnesium chloride;
alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, 2-ethylhexoxymagnesium;
aryloxymagnesium such as phenoxymagnesium;
Examples thereof include magnesium compounds having no reducing ability, such as magnesium carboxylates such as magnesium stearate.

Magnesium compounds also include organomagnesium compounds and organomagnesium halide compounds typified by Grignard reagents.
1 type(s) or 2 or more types can be used for a magnesium compound. Also, the magnesium compound may be a complex compound with other metals, a double compound, or a mixture with other metal compounds.

Among these, magnesium halides such as magnesium chloride are preferred, and alkoxymagnesium such as ethoxymagnesium is also preferred. Alternatively, an organomagnesium compound having a reducing ability such as a Grignard reagent may be brought into contact with a titanium halide, a silicon halide, or a halogenated alcohol.

The electron donor (a) having 1 to 5 carbon atoms includes, for example, alcohols, aldehydes, amines, and carboxylic acids that satisfy the aforementioned carbon number requirements.
Examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and ethylene glycol. Among these, alcohols having 1 to 3 carbon atoms are preferred, ethanol, n-propanol and isopropanol are more preferred, and ethanol is even more preferred.

Examples of the aldehyde include ethanal (acetaldehyde), propanal, n-butanal and n-pentanal.
Examples of the amine include ethylamine, diethylamine, trimethylamine, and diethylmethylamine.

Examples of the carboxylic acid include acetic acid, propionic acid, butanoic acid, and pentanoic acid.
Alcohols having 1 to 5 carbon atoms are particularly preferred as the electron donor (a).

One or more electron donors (a) can be used.
The electron donor (a) generally has high reactivity with the organometallic compound catalyst component (II) described below, and exhibits catalytic activity quickly. Catalysts with high polymerization activity are often obtained.

Examples of the electron donor (b) having 6 to 30 carbon atoms include alcohols, aldehydes, amines, and carboxylic acids that satisfy the above-described carbon number requirements. The electron donor (b) preferably has 6 to 20 carbon atoms.

Examples of the alcohol include
Aliphatic alcohols such as hexanol, 2-methylpentanol, 2-ethylbutanol, n-heptanol, n-octanol, 2-ethylhexanol, decanol, dodecanol;
Alicyclic alcohols such as cyclohexanol and methylcyclohexanol;
aromatic alcohols such as benzyl alcohol, methylbenzyl alcohol;
alkoxy group-containing aliphatic alcohols such as n-butyl cellosolve;
is mentioned.

Among these alcohols, aliphatic alcohols are preferred, hexanol, 2-ethylhexanol, decanol and dodecanol are more preferred, and 2-ethylhexanol is even more preferred.

Examples of the aldehyde include aldehydes having 7 or more carbon atoms such as capricaldehyde and 2-ethylhexylaldehyde.
Examples of the amine include amines having 6 to 30 carbon atoms such as heptylamine, octylamine, nonylamine, laurylamine and 2-ethylhexylamine.

Examples of the carboxylic acid include organic carboxylic acids having 6 to 30 carbon atoms such as caprylic acid and 2-ethylhexanoic acid.
Electron donors (b) tend to be able to solubilize magnesium compounds in small amounts (mole units).

Alcohols having 6 to 12 carbon atoms are particularly preferred as the electron donor (b).
One or more electron donors (b) can be used.
As a combination of the electron donor (a) and the electron donor (b), both are preferably alcohols, the electron donor (a) is an alcohol having 1 to 5 carbon atoms, and the electron donor ( More preferably, b) is a C6-C12 alcohol.

The amounts of the magnesium compound, the electron donor (a) and the electron donor (b) used in preparing the liquid magnesium compound (A) vary depending on the type, contact conditions, and the like. For example, the electron donor (a) is usually 0.1 to 20 mol, preferably 0.2 to 10 mol, more preferably 0.2 to 8 mol, per 1 mol of the magnesium compound. The amount of the electron donor (b) is generally 0.5 to 20 mol, preferably 1 to 10 mol, more preferably 1 to 5 mol, per 1 mol of the magnesium compound. The total amount of electron donor (a) and electron donor (b) is usually 1.1 to 25 mol, preferably 1.5 to 10 mol, more preferably 2 to 5 mol, per 1 mol of the magnesium compound. be.

The electron donor (a) is preferably used in a smaller amount than the electron donor (b). Specifically, the molar ratio [(a)/(b)] between the amount of the electron donor (a) used and the amount of the electron donor (b) used is preferably less than 1, more preferably 0.8 less than 0.6, particularly preferably less than 0.5, particularly preferably less than 0.4. When the amount ratio of the electron donor (a) and the electron donor (b) is within the above range, the magnesium compound tends to be easily solubilized. Electron donor (a), electron donor (b), electron donor (B1) and electron donor (B2) are preferably heteroatom-containing compounds other than cyclic ether compounds.

In order to obtain catalyst particles with excellent particle properties, it is advantageous to use a solvent-soluble magnesium compound. In order to obtain a highly active solid titanium catalyst component, it is preferable to use the electron donor (a) as described above. In the present invention, even if the electron donor (b) and the electron donor (a) are used in combination, a solid titanium catalyst component having excellent particle properties can be obtained without impairing the effect of exhibiting high activity in ethylene polymerization. can be done.

Preparation of the liquid magnesium compound (A) is preferably carried out in a liquid hydrocarbon medium. Examples of liquid hydrocarbon media include hydrocarbon compounds such as heptane, octane, and decane. The magnesium compound can be used in an amount such that the concentration of magnesium in the liquid hydrocarbon medium is preferably 0.1 to 20 mol/liter, more preferably 0.5 to 5 mol/liter.
The liquid magnesium compound (A) may be dissolved in a known liquid hydrocarbon medium such as heptane, octane, or decane.

<Electron donor (B)>
The electron donors (B1) and (B2) are collectively described below as the electron donor (B).
Examples of the electron donor (B) used in the production of the titanium catalyst component (I) include, for example, Preferred examples include electron donors used in the preparation of solid titanium catalyst components for the polymerization of α-olefins.

≪Polyesters≫
Among the above electron donors, polyethers are often preferable electron donors in the present invention. Polyethers are, for example, compounds having two or more ether linkages that exist through multiple atoms.

Examples of the polyethers include compounds in which the atoms present between ether bonds are carbon, silicon, oxygen, nitrogen, sulfur, phosphorus, boron, or two or more selected from these. Among these, compounds in which relatively bulky substituents are bonded to atoms between ether bonds and atoms present between two or more ether bonds contain a plurality of carbon atoms are preferred. For example, compounds represented by formula (b1) are preferred.

式（ｂ１）中、ｍは１～１０の整数、好ましくは３～１０の整数、より好ましくは３～５の整数である。Ｒ¹¹、Ｒ¹²、Ｒ³¹～Ｒ³⁶は、それぞれ独立に、水素原子、または炭素、水素、酸素、フッ素、塩素、臭素、ヨウ素、窒素、硫黄、リン、ホウ素およびケイ素から選択される少なくとも１種の元素を有する置換基である。

In formula (b1), m is an integer of 1-10, preferably an integer of 3-10, more preferably an integer of 3-5. R ¹¹ , R ¹² , R ³¹ to R ³⁶ are each independently a hydrogen atom or at least one selected from carbon, hydrogen, oxygen, fluorine, chlorine, bromine, iodine, nitrogen, sulfur, phosphorus, boron and silicon. It is a substituent having a seed element.

R ¹¹ and R ¹² are each independently preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group and 2-ethylhexyl. cycloalkyl groups such as cyclopentyl group and cyclohexyl group; cyclohexylalkyl groups such as cyclohexylmethyl; preferably ethyl group, n-propyl group, isopropyl group, n-butyl group and isobutyl group; is the base.

When m is an integer of 2 or more, at least one of R ¹¹ and R ¹² of -C(R ¹¹ )(R ¹² )- is preferably the above hydrocarbon group. In this case, R ¹¹ and R ¹² of the other —C(R ¹¹ )(R ¹² )— may be hydrogen atoms, for example.

R ³¹ to R ³⁶ are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, more preferably a hydrogen atom, or a methyl group, ethyl group, n-propyl group, isopropyl group, n - is an alkyl group such as a butyl group and an isobutyl group, more preferably a hydrogen atom or a methyl group.

Optional R ¹¹ , R ¹² , R ³¹ to R ³⁶ , preferably R ¹¹ and R ¹² may jointly form a ring other than a benzene ring, and the main chain contains an atom other than carbon. may be
Examples of polyethers include
2,2-dicyclohexyl-1,3-dimethoxypropane,
2,2-diethyl-1,3-dimethoxypropane,
2,2-dipropyl-1,3-dimethoxypropane,
2,2-dibutyl-1,3-dimethoxypropane,
2-methyl-2-propyl-1,3-dimethoxypropane,
2-methyl-2-ethyl-1,3-dimethoxypropane,
2-methyl-2-isopropyl-1,3-dimethoxypropane,
2-methyl-2-cyclohexyl-1,3-dimethoxypropane,
2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane,
2-methyl-2-isobutyl-1,3-dimethoxypropane,
2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane,
2,2-diisobutyl-1,3-dimethoxypropane,
2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,
2,2-diisobutyl-1,3-diethoxypropane,
2,2-diisobutyl-1,3-dibutoxypropane,
2-isobutyl-2-isopropyl-1,3-dimethoxypropane,
2,2-di-s-butyl-1,3-dimethoxypropane,
2,2-di-t-butyl-1,3-dimethoxypropane,
2,2-dineopentyl-1,3-dimethoxypropane,
2-isopropyl-2-isopentyl-1,3-dimethoxypropane,
2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane,
2,3-dicyclohexyl-1,4-diethoxybutane,
2,3-diisopropyl-1,4-diethoxybutane,
2,4-diisopropyl-1,5-dimethoxypentane,
2,4-diisobutyl-1,5-dimethoxypentane,
2,4-diisoamyl-1,5-dimethoxypentane,
3-methoxymethyltetrahydrofuran,
3-methoxymethyldioxane,
1,2-diisobutoxypropane,
1,2-diisobutoxyethane,
1,3-diisoamyloxyethane,
1,3-diisoamyloxypropane,
1,3-diisononeopentyloxyethane,
1,3-dineopentyloxypropane,
2,2-tetramethylene-1,3-dimethoxypropane,
2,2-pentamethylene-1,3-dimethoxypropane,
2,2-hexamethylene-1,3-dimethoxypropane,
1,2-bis(methoxymethyl)cyclohexane,
2-cyclohexyl-2-ethoxymethyl-1,3-diethoxypropane,
2-cyclohexyl-2-methoxymethyl-1,3-dimethoxypropane,
2,2-diisobutyl-1,3-dimethoxycyclohexane,
2-isopropyl-2-isoamyl-1,3-dimethoxycyclohexane,
2-cyclohexyl-2-methoxymethyl-1,3-dimethoxycyclohexane,
2-isopropyl-2-methoxymethyl-1,3-dimethoxycyclohexane,
2-isobutyl-2-methoxymethyl-1,3-dimethoxycyclohexane,
2-cyclohexyl-2-ethoxymethyl-1,3-diethoxycyclohexane,
2-cyclohexyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,
2-isopropyl-2-ethoxymethyl-1,3-diethoxycyclohexane,
2-isopropyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,
2-isobutyl-2-ethoxymethyl-1,3-diethoxycyclohexane,
2-isobutyl-2-ethoxymethyl-1,3-dimethoxycyclohexane may be mentioned.

Among these, 1,3-diethers are preferred, and 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1 ,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, and 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane are more preferable.

<<Compound having a plurality of carboxylic acid ester groups>>
Examples of other electron donors (B) include compounds having a plurality of carboxylic acid ester groups such as dicarboxylic acid ester compounds, and specific examples include compounds represented by formula (b2). When the compound represented by the formula (b2) is used, the particle properties of the resulting ethylene polymer may be excellently controlled in some cases.

式（ｂ２）中、Ｃ^aは炭素原子を表す。式（ｂ２）の骨格中の炭素間結合は、すべてが単結合であることが好ましいが、骨格中の、Ｃ^a－Ｃ^a結合以外のいずれかの炭素間結合は、二重結合に置き換えられていてもよい。

In formula (b2), C ^a represents a carbon atom. All of the carbon-carbon bonds in the skeleton of formula (b2) are preferably single bonds, but any carbon-carbon bond other than the C ^a -C ^a bond in the skeleton is replaced with a double bond. may be

R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ .
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, particularly preferably 2 to 3 carbon atoms. be. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, neopentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group and decyl. group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, preferably methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, neopentyl group. , hexyl group, heptyl group, octyl group, 2-ethylhexyl group and decyl group, more preferably methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, neopentyl group and hexyl group, heptyl group, octyl group and 2-ethylhexyl group, more preferably ethyl group, n-propyl group and isopropyl group.

A plurality of R are each independently an atom selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group, or is the base.

As R other than a hydrogen atom, among these, a hydrocarbon group having 1 to 20 carbon atoms is preferable, and a hydrocarbon group having 1 to 10 carbon atoms is more preferable. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, n-pentyl group, n-hexyl group, octyl group and vinyl group. Alicyclic hydrocarbon groups such as cyclopentyl group and cyclohexyl group; Aromatic hydrocarbon groups such as phenyl group, preferably aliphatic hydrocarbon groups, more preferably ethyl group , n-propyl group and isopropyl group.

When R is the above group, not only can the formation of a solvent-soluble component derived from a low molecular weight described below be suppressed, but also the particle properties are excellent, which is preferable.
At least two of the plurality of R's may be bonded to each other to form a ring, and the skeleton of the ring formed by bonding the R's together contains a double bond or a heteroatom. Alternatively, when the ring skeleton contains two or more C ^a to which COOR ¹ is bound, the number of carbon atoms forming the ring skeleton is usually 5 to 10.

R ² and R ³ that are not COOR ¹ are preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Among these, a hydrogen atom; a secondary alkyl group such as an isopropyl group, a sec-butyl group, a 2-pentyl group and a 3-pentyl group; a cycloalkyl group such as a cyclohexyl group and a cyclopentyl group; a cycloalkyl group such as a cyclohexylmethyl group; Alkyl groups are preferred. At least one of R ² and R ³ that is not COOR ¹ is preferably a hydrogen atom.

Examples of compounds represented by formula (b2) include
2,3-bis(2-ethylbutyl)diethyl succinate,
diethyl 2,3-dibenzylsuccinate,
diethyl 2,3-diisopropylsuccinate,
diisobutyl 2,3-diisopropylsuccinate,
2,3-bis(cyclohexylmethyl)diethyl succinate,
diethyl 2,3-diisobutylsuccinate,
2,3-dineopentyl diethyl succinate,
diethyl 2,3-dicyclopentylsuccinate,
The (S,R)(S,R) form of diethyl 2,3-dicyclohexylsuccinate, pure or optionally in racemic form, as a mixture. The use of these dicarboxylic acid ester compounds is preferable in terms of excellent control of the molecular weight and molecular weight distribution of the resulting ethylene polymer.

Other examples include:
diethyl sec-butylsuccinate,
diethyl thexyl succinate,
diethyl cyclopropylsuccinate,
diethyl norbornyl succinate,
(10-) diethyl perhydronaphthyl succinate,
diethyl trimethylsilylsuccinate,
diethyl methoxysuccinate,
diethyl p-methoxyphenylsuccinate,
diethyl p-chlorophenylsuccinate,
diethyl phenylsuccinate,
diethyl cyclohexylsuccinate,
diethyl benzylsuccinate,
(cyclohexylmethyl)diethyl succinate,
diethyl t-butylsuccinate,
diethyl isobutylsuccinate,
diethyl isopropyl succinate,
diethyl neopentyl succinate,
diethyl 2,2-dimethylsuccinate,
diethyl 2-ethyl-2-methylsuccinate,
2-benzyl-2-isopropyl diethyl succinate,
2-(cyclohexylmethyl)-2-diethyl isobutylsuccinate,
diethyl 2-cyclopentyl-2-n-propylsuccinate,
diethyl 2,2-diisobutylsuccinate,
diethyl 2-cyclohexyl-2-ethylsuccinate,
diethyl 2-isopropyl-2-methylsuccinate,
diethyl 2,2-diisopropylsuccinate,
diethyl 2-isobutyl-2-ethylsuccinate,
diethyl 2-(1,1,1-trifluoro-2-propyl)-2-methylsuccinate,
diethyl 2-isopentyl-2-isobutylsuccinate,
diethyl 2-phenyl-2-n-butylsuccinate,
diisobutyl 2,2-dimethylsuccinate,
diisobutyl 2-ethyl-2-methylsuccinate,
diisobutyl 2-benzyl-2-isopropylsuccinate,
2-(cyclohexylmethyl)-2-isobutyl diisobutyl succinate,
diisobutyl 2-cyclopentyl-2-n-propylsuccinate,
diethyl cyclobutane-1,2-dicarboxylate,
Diethyl 3-methylcyclobutane-1,2-dicarboxylate may be mentioned.

Preferable examples of the compound represented by formula (b2) in which the R groups are bonded to form a cyclic structure include the compound represented by formula (b3).

式（ｂ３）中、ｎは５～１０の整数、好ましくは５～８の整数、より好ましくは５～７の整数、さらに好ましくは６である。Ｃ^aおよびＣ^bは炭素原子を表す。式（ｂ３）の環状骨格中の炭素間結合は、すべてが単結合であることが好ましいが、環状骨格中の、Ｃ^a－Ｃ^a結合、およびＲ³が水素原子である場合のＣ^a－Ｃ^b結合以外のいずれかの炭素間結合は、二重結合に置き換えられていてもよい。

In formula (b3), n is an integer of 5-10, preferably an integer of 5-8, more preferably an integer of 5-7, still more preferably 6. C ^a and C ^b represent carbon atoms. ^All of the carbon-carbon bonds ⁱⁿ the cyclic skeleton of formula (b3) ^are preferably single bonds ^. Any carbon-carbon bond other than the C ^b bond may be replaced with a double bond.

R ² and R ³ are each independently COOR ¹ or R′, and at least one of R ² and R ³ is COOR ¹ . It is preferred that R ² is COOR ¹ and R ³ is R'.
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, particularly preferably 2 to 3 carbon atoms. and specific examples and preferred examples are the same as the hydrocarbon group for R ¹ of the compound represented by formula (b2).

In formula (b3), A is a divalent group represented by formula (g) ^{or a heteroatom excluding an oxygen atom, preferably a divalent group represented by formula (g), Ca , C b and} A The ring formed by is preferably a cyclic carbon structure, and particularly preferably a saturated alicyclic structure in which the cyclic structure is composed only of carbon.

式（ｂ３）および（ｇ）中の複数個あるＲ'は、それぞれ独立に、水素原子、炭素数１～２０の炭化水素基、ハロゲン原子、窒素含有基、酸素含有基、リン含有基、ハロゲン含有基およびケイ素含有基から選ばれる原子または基である。

Multiple R' in formulas (b3) and (g) are each independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen It is an atom or group selected from containing groups and silicon-containing groups.

Among these, R′ other than a hydrogen atom is preferably a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrocarbon group having 1 to 10 carbon atoms. It is the same as the hydrocarbon group for R in the compounds shown.

When R' is the above group, not only can the formation of solvent-soluble components derived from low-molecular weights described below be suppressed, but the particle properties are also excellent, which is preferable.
R' may be bonded to each other to form a ring, and the skeleton of the ring formed by bonding R' to each other may contain a double bond or a heteroatom other than oxygen. , When the ring skeleton contains two or more C ^a to which COOR ¹ is bound, the number of carbon atoms forming the ring skeleton is usually 5 to 10. Such ring skeletons include, for example, a norbornane skeleton and a tetracyclododecane skeleton.

A plurality of R' may be a carbonyl structure-containing group such as a carboxylic acid ester group, an alkoxy group, a siloxy group, an aldehyde group or an acetyl group.
R' is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

Examples of compounds represented by formula (b3) include
diethyl cyclohexane-1,2-dicarboxylate,
di-n-propyl cyclohexane-1,2-dicarboxylate,
diisopropyl cyclohexane-1,2-dicarboxylate,
diethyl cyclohexane-1,3-dicarboxylate,
di-n-propyl cyclohexane-1,3-dicarboxylate,
diisopropyl cyclohexane-1,3-dicarboxylate,
diethyl 3-methylcyclohexane-1,2-dicarboxylate,
di-n-propyl 3-methylcyclohexane-1,2-dicarboxylate,
diisopropyl 3-methylcyclohexane-1,2-dicarboxylate,
diethyl 4-methylcyclohexane-1,3-dicarboxylate,
di-n-propyl 4-methylcyclohexane-1,3-dicarboxylate,
diethyl 4-methylcyclohexane-1,2-dicarboxylate,
di-n-propyl 4-methylcyclohexane-1,2-dicarboxylate,
diisopropyl 4-methylcyclohexane-1,2-dicarboxylate,
diethyl 5-methylcyclohexane-1,3-dicarboxylate,
di-n-propyl 5-methylcyclohexane-1,3-dicarboxylate,
diisopropyl 5-methylcyclohexane-1,3-dicarboxylate,
3,4-dimethylcyclohexane-1,2-dicarboxylate diethyl,
di-n-propyl 3,4-dimethylcyclohexane-1,2-dicarboxylate,
diisopropyl 3,4-dimethylcyclohexane-1,2-dicarboxylate,
3,6-dimethylcyclohexane-1,2-dicarboxylate diethyl,
di-n-propyl 3,6-dimethylcyclohexane-1,2-dicarboxylate,
diisopropyl 3,6-dimethylcyclohexane-1,2-dicarboxylate,
diethyl 3-hexylcyclohexane-1,2-dicarboxylate,
di-n-propyl 3-hexylcyclohexane-1,2-dicarboxylate,
di-n-propyl 3,6-dihexylcyclohexane-1,2-dicarboxylate,
diethyl 3-hexyl-6-pentylcyclohexane-1,2-dicarboxylate,
diethyl cyclopentane-1,2-dicarboxylate,
di-n-propyl cyclopentane-1,2-dicarboxylate,
diisopropyl cyclopentane-1,2-dicarboxylate,
diethyl cyclopentane-1,3-dicarboxylate,
di-n-propyl cyclopentane-1,3-dicarboxylate,
diethyl 3-methylcyclopentane-1,2-dicarboxylate,
di-n-propyl 3-methylcyclopentane-1,2-dicarboxylate,
diisopropyl 3-methylcyclopentane-1,2-dicarboxylate,
diethyl 4-methylcyclopentane-1,3-dicarboxylate,
di-n-propyl 4-methylcyclopentane-1,3-dicarboxylate,
diisopropyl 4-methylcyclopentane-1,3-dicarboxylate,
diethyl 4-methylcyclopentane-1,2-dicarboxylate,
di-n-propyl 4-methylcyclopentane-1,2-dicarboxylate,
diisopropyl 4-methylcyclopentane-1,2-dicarboxylate,
diethyl 5-methylcyclopentane-1,3-dicarboxylate,
di-n-propyl 5-methylcyclopentane-1,3-dicarboxylate,
diethyl 3,4-dimethylcyclopentane-1,2-dicarboxylate,
di-n-propyl 3,4-dimethylcyclopentane-1,2-dicarboxylate,
diisopropyl 3,4-dimethylcyclopentane-1,2-dicarboxylate,
diethyl 3,5-dimethylcyclopentane-1,2-dicarboxylate,
di-n-propyl 3,5-dimethylcyclopentane-1,2-dicarboxylate,
diisopropyl 3,5-dimethylcyclopentane-1,2-dicarboxylate,
diethyl 3-hexylcyclopentane-1,2-dicarboxylate,
diethyl 3,5-dihexylcyclopentane-1,2-dicarboxylate,
diethyl cycloheptane-1,2-dicarboxylate,
di-n-propyl cycloheptane-1,2-dicarboxylate,
diisopropyl cycloheptane-1,2-dicarboxylate,
diethyl cycloheptane-1,3-dicarboxylate,
di-n-propyl cycloheptane-1,3-dicarboxylate,
diethyl 3-methylcycloheptane-1,2-dicarboxylate,
di-n-propyl 3-methylcycloheptane-1,2-dicarboxylate,
diisopropyl 3-methylcycloheptane-1,2-dicarboxylate,
4-methylcycloheptane-1,3-dicarboxylate diethyl,
diethyl 4-methylcycloheptane-1,2-dicarboxylate,
di-n-propyl 4-methylcycloheptane-1,2-dicarboxylate,
diisopropyl 4-methylcycloheptane-1,2-dicarboxylate,
5-methylcycloheptane-1,3-dicarboxylate diethyl,
3,4-dimethylcycloheptane-1,2-dicarboxylate diethyl,
di-n-propyl 3,4-dimethylcycloheptane-1,2-dicarboxylate,
diisopropyl 3,4-dimethylcycloheptane-1,2-dicarboxylate,
3,7-dimethylcycloheptane-1,2-dicarboxylate diethyl,
di-n-propyl 3,7-dimethylcycloheptane-1,2-dicarboxylate,
diisopropyl 3,7-dimethylcycloheptane-1,2-dicarboxylate,
diethyl 3-hexylcycloheptane-1,2-dicarboxylate,
diethyl 3,7-dihexylcycloheptane-1,2-dicarboxylate,
diethyl cyclooctane-1,2-dicarboxylate,
diethyl 3-methylcyclooctane-1,2-dicarboxylate,
diethyl cyclodecane-1,2-dicarboxylate,
diethyl 3-methylcyclodecane-1,2-dicarboxylate,
diethyl cyclooxypentane-3,4-dicarboxylate,
Dicarboxylic acid esters such as 3,6-dicyclohexylcyclohexane-1,2-dicarboxylic acid diethyl can be mentioned.

Compounds having the above dicarboxylic acid ester structure have isomers such as cis and trans isomers.
Among the above compounds, particularly preferred are cyclohexanedicarboxylic acid esters in which n=6 in formula (b3). The reason for this is not only the catalytic performance but also the fact that these compounds can be produced relatively inexpensively using the Diels Alder reaction. Furthermore, when cyclohexanedicarboxylic acid esters are used, it is possible to obtain a polymer that is excellent in hydrogen responsiveness, maintains high activity, and has excellent particle properties.

As the electron donor (B), other polyvalent carboxylic acid esters described below, specifically, diethyl succinate, dibutyl succinate, diethyl methylmalonate, diethyl ethylmalonate, diethyl isopropylmalonate, butyl diethyl malonate, diethyl phenylmalonate, diethyl diethylmalonate, diethyl dibutylmalonate, monooctyl maleate, dioctyl maleate, dibutyl maleate, dibutyl butyl maleate, diethyl butyl maleate, di-2-ethylhexyl fumarate, Aliphatic polycarboxylic acid esters such as diethyl itaconate and dioctyl citraconate; aromatic polycarboxylic acid esters such as phthalic acid esters, naphthalenedicarboxylic acid esters, triethyl trimellitate and dibutyl trimellitate; 3,4-flange Examples include heterocyclic polycarboxylic acid esters such as carboxylic acids. However, in some cases, it is preferable to avoid using a polyfunctional aromatic compound or keep it to the minimum necessary for safety and health reasons.

Other examples of polycarboxylic acid esters include long-chain dicarboxylic acids such as diethyl adipate, diisobutyl adipate, diisopropyl sebacate, di-n-butyl sebacate, di-n-octyl sebacate, and di-2-ethylhexyl sebacate. Esters of acids can be mentioned.

<<Other electron donors>>
Examples of other electron donors (B) include, for example, one or more compounds selected from the following acid halides, acid amides, nitriles, acid anhydrides and organic acid esters, tetraalkoxysilane, An alkoxysilane compound represented by the general formula R _n Si(OR') _4-n described below is also included.

Specifically, acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride, and anisic acid chloride;
Acid amides such as N,N-dimethylamide acetate, N,N-diethylamide benzoate, and N,N-dimethylamide toluate;
Nitriles such as acetonitrile, benzonitrile, trinitrile;
acid anhydrides such as acetic anhydride, phthalic anhydride, benzoic anhydride;
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, benzoic acid Methyl, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate , ethyl anisate, ethyl ethoxybenzoate, γ-butyl lactone, δ-valerolactone, coumarin, phthalide, organic acid esters having 2 to 18 carbon atoms such as ethyl carbonate;
Tetraalkoxysilanes such as tetraethoxysilane, tetrabutoxysilane;
is mentioned.

Among organic acid esters, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate , ethyl ethylbenzoate, and ethyl ethoxybenzoate are preferred.

≪Preferred example≫
Among the electron donors (B), an embodiment in which polyethers are essential is preferable because the effects of the present invention may be particularly remarkable.

The compound represented by the formula (b3) or the organic acid ester may be formed in the process of preparing the titanium catalyst component (I), for example, in the process of contacting with the magnesium compound (A). You can also let More specifically, when the magnesium compound (A) is brought into contact with the electron donor ( B) can also be included in the titanium catalyst component (I).

According to the studies of the present inventors, when the electron donor (B) is used, the molecular weight distribution is slightly narrower when comparing polymers with the same intrinsic viscosity [η], that is, the same molecular weight, and the solvent-soluble component It can be seen that there is a tendency to produce less by-products. In addition, the use of the electron donor (B) tends to facilitate obtaining a solid titanium catalyst component having good particle properties.

<Liquid titanium compound (C)>
Examples of the liquid titanium compound (C) used for preparing the titanium catalyst component (I) include titanium compounds described in JP-A-58-83006 and JP-A-56-811. A specific example of the liquid titanium compound (C) is a tetravalent titanium compound represented by formula (4).

Ti(OR) _g X _4-g (4)
In formula (4), R is an aliphatic hydrocarbon group having 1 to 5 carbon atoms, X is a halogen atom, and 0≤g≤4.

Examples of the tetravalent titanium compound represented by formula (4) include:
Titanium tetrahalides such as _TiCl4 , _TiBr4 ;
Ti( _OCH3 ) _Cl3 , Ti( _OC2H5 )Cl3 _, Ti(On- _{C4H9 ) Cl3 , Ti} ( _{OC2H5 )} Br3 _, Ti(Oiso- _C4H9 ) trihalogenated alkoxytitanium such as _Br3 ;
Dihalogenated _alkoxy titanium such as Ti( _{OCH3 ) 2Cl2} , Ti( _OC2H5 ) _{2Cl2 ;}
monohalogenated alkoxy titaniums such as _{Ti(OCH3)3Cl, Ti(O n-C4H9)3Cl , Ti ( OC2H5 ) 3Br ;}
Tetraalkoxy titanium such as Ti( _{OCH3 ) 4} , Ti( _OC2H5 ) ₄ , Ti( _OC4H9 ) ₄ , Ti(O2- _ethylhexyl ) ₄ ;
is mentioned.

Among these, titanium tetrahalide is preferred, and titanium tetrachloride is more preferred.
One or two or more liquid titanium compounds (C) can be used.
In the present invention, at least one of the liquid magnesium compound (A) and the liquid titanium compound (C) preferably contains halogen. When neither the liquid magnesium compound (A) nor the titanium compound (C) contains halogen, they can be contacted with a known halogen-containing compound such as a halogen-containing silicon compound in any step. A representative example of such a halogen-containing compound is silicon tetrachloride.

[Ethylene polymerization catalyst]
The ethylene polymerization catalyst of the present invention comprises the solid titanium catalyst component (I) for ethylene polymerization obtained as described above and the organometallic compound catalyst component (II), and optionally an electron donor ( III).
The ethylene polymerization catalyst of the present invention can also be used to polymerize α-olefins such as propylene.

<Organometallic compound catalyst component (II)>
The organometallic compound catalyst component (II) is preferably an organometallic compound containing a metal selected from Groups 1, 2 and 13 of the periodic table. Organometallic compounds of group 2 metals such as complex alkylated products with aluminum, Grignard reagents and organomagnesium compounds can be mentioned. Among these, organoaluminum compounds are preferred.

Specific examples of the organometallic compound catalyst component (II) include organometallic compound catalyst components described in known documents such as EP585869A1. Especially preferred are organoaluminum compounds such as triethylaluminum, tributylaluminum, triisobutylaluminum, trioctylaluminum and diethylaluminum hydride.

<Electron donor (III)>
Organosilicon compounds are preferred as the electron donor (III).
Examples of organosilicon compounds include compounds represented by formula (5).
_RnSi (OR') _4-n (5)
In formula (5), R and R' are each independently an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 20 carbon atoms, where 0<n<4.

Examples of organosilicon compounds represented by formula (5) include diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, phenyltriethoxysilane, cyclohexyltrimethoxysilane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane , dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane; tricyclopentylmethoxysilane, dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane, cyclopentyldimethylethoxysilane. Among these, vinyltriethoxysilane, diphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, and dicyclopentyldimethoxysilane are preferred.

One or more electron donors (III) can be used.
Examples of the electron donor (III) include the electron donor (B), the electron donor (a) and the electron donor (b) used in the production of the solid titanium catalyst component (I) for ethylene polymerization. compounds, and preferred examples include polyethers.

<Other ingredients>
The ethylene polymerization catalyst of the present invention may optionally contain other components useful for olefin polymerization, such as antistatic agents, particle aggregating agents, and storage stabilizers, in addition to the components described above.

[Ethylene polymerization method]
The ethylene polymerization method of the present invention comprises a step of polymerizing ethylene alone or polymerizing an olefin containing ethylene using the ethylene polymerization catalyst to obtain an ethylene polymer. That is, homopolymerization of ethylene or copolymerization of ethylene with other olefins is carried out in the presence of the ethylene polymerization catalyst.

In the ethylene polymerization method of the present invention, it is also possible to carry out the main polymerization in the presence of a prepolymerization catalyst obtained by prepolymerizing an olefin in the presence of the ethylene polymerization catalyst of the present invention. . This prepolymerization is carried out by prepolymerizing olefin in an amount of usually 0.1 to 1000 g, preferably 0.3 to 500 g, more preferably 1 to 200 g per 1 g of the ethylene polymerization catalyst.

In prepolymerization, a catalyst with a concentration higher than that in the system in main polymerization can be used. The concentration of the titanium catalyst component (I) in the prepolymerization is usually 0.001 to 200 mmol, preferably 0.01 to 50 mmol, more preferably 0.1 to 20 mmol per liter of liquid medium, in terms of titanium atoms. is.

The amount of the organometallic compound catalyst component (II) in the prepolymerization is usually 0.1 to 1000 g, preferably 0.3 to 500 g of polymer per 1 g of the titanium catalyst component (I). It is usually 0.1 to 300 mol, preferably 0.5 to 100 mol, particularly preferably 1 to 50 mol, per 1 mol of titanium atom in the titanium catalyst component (I).

In the prepolymerization, an electron donor (III) or the like can be used as necessary. It is preferably used in an amount of 0.5 to 30 mol, more preferably 1 to 10 mol.

Prepolymerization can be carried out under mild conditions by adding the olefin and the above catalyst components to an inert hydrocarbon medium. The prepolymerization is preferably carried out batchwise when using an inert hydrocarbon medium.

Examples of inert hydrocarbon media include
Aliphatic hydrocarbons such as propane, butane, heptane, heptane, heptane, octane, decane, dodecane, kerosene;
Alicyclic hydrocarbons such as cycloheptane, cycloheptane, methylcycloheptane;
aromatic hydrocarbons such as benzene, toluene, xylene;
Halogenated hydrocarbons such as ethylene chloride, chlorobenzene;
is mentioned.

One or more inert hydrocarbon media can be used.
Among the inert hydrocarbon media, aliphatic hydrocarbons are preferred.
On the other hand, the prepolymerization can be carried out using the olefin itself as a solvent, or the prepolymerization can be carried out in a substantially solvent-free state. In this case, it is preferable to carry out the preliminary polymerization continuously. Known olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1-pentene can be used for prepolymerization. Among these, ethylene and propylene are preferred.

The temperature for prepolymerization is usually -20 to +100°C, preferably -20 to +80°C, more preferably 0 to +40°C.
Next, the main polymerization (polymerization) will be described.

In the main polymerization, ethylene may be used alone, or other olefins may be used in addition to ethylene. Specifically, α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene , 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, with propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene being preferred. In addition to these, aromatic vinyl compounds such as styrene and allylbenzene; and alicyclic vinyl compounds such as vinylcycloheptane can also be used. It is also possible to use two or more of these compounds in combination. Furthermore, compounds having polyunsaturated bonds such as conjugated dienes such as cyclopentene, cycloheptene, norbornene, tetracyclododecene, isoprene and butadiene, and non-conjugated dienes such as dienes can be used together with ethylene and α-olefins as starting materials for polymerization. can also

In the present invention, prepolymerization and main polymerization can be carried out by either liquid phase polymerization such as solution polymerization or slurry polymerization, or gas phase polymerization. It is particularly preferable to carry out the main polymerization by slurry polymerization. When the main polymerization takes the form of slurry polymerization, it is preferable to use, as the reaction solvent, the inert hydrocarbon medium used in the prepolymerization described above.

For the main polymerization in the ethylene polymerization method of the present invention, the solid titanium catalyst component for ethylene polymerization (I) is usually 0.0001 to 0.5 mmol, preferably 0.0001 to 0.5 mmol in terms of titanium atoms per liter of polymerization volume. It is used in an amount of 0.005 to 0.1 millimolar. The amount of the organometallic compound catalyst component (II) is usually 1 to 2000 mol, preferably 5 to 500 mol in terms of metal atom, per 1 mol of the titanium atom in the preliminary polymerization catalyst component in the polymerization system. used in When the electron donor (III) is used, it is usually 0.001 to 50 mol, preferably 0.01 to 30 mol, more preferably 0, per 1 mol of the metal atom of the organometallic compound catalyst component (II). It is used in an amount of 0.05 to 20 moles.

If hydrogen is used in the main polymerization, the molecular weight of the obtained ethylene polymer can be adjusted, and an ethylene polymer having a high melt flow rate (hereinafter also referred to as "MFR") can be obtained. When the ethylene polymerization catalyst of the present invention is used, it tends to be easier to obtain a polymer having a high MFR with a smaller amount of hydrogen than a conventional ethylene polymerization catalyst.

The reason why a polymer with a high MFR can be easily obtained with a small amount of hydrogen is unknown, but it is considered that the electron donor (B) promotes the chain transfer reaction with hydrogen. This tendency is particularly noticeable in catalysts containing a solid titanium catalyst component containing an electron donor represented by the above formula (b1).

In the main polymerization in the present invention, the polymerization temperature is usually 20 to 250° C., preferably 50 to 200° C., and the pressure is usually atmospheric pressure to 10 MPa, preferably 0.2 to 5 MPa. In the case of slurry polymerization, the polymerization temperature is generally 20-100° C., preferably 50-90° C., and the pressure is generally normal pressure to 1.5 MPa, preferably 0.2-1 MPa. In the polymerization method of the present invention, polymerization can be carried out in any of a batch system, a semi-continuous system and a continuous system. Furthermore, the polymerization can be carried out in two or more stages by changing the reaction conditions.

Since the ethylene polymer obtained by the ethylene polymerization method of the present invention has excellent particle properties and a high bulk density, it is easy to increase the slurry concentration at the time of production, so that it can be produced with high productivity. In addition, the slightly narrow molecular weight distribution tends to result in a low proportion of low-molecular-weight polymers being produced. Lives tend to be low. The amount of such solvent-soluble components by-produced varies depending on the MFR of the ethylene polymer to be produced (the higher the MFR, the higher the solvent-soluble components tend to be). It is preferable that the solvent-soluble component is 8% or less when producing the coalescence.

The solvent soluble content (SP) can be calculated by the following formula.
SP (%) = 100 × (α) / ((α) + (β))
(α): amount of powdery polymer
(β): Amount of ethylene polymer dissolved in solvent used for polymerization Incidentally, (β) is measured as the weight of a solid obtained by distilling off the solvent from the filtrate separated by filtration after the polymerization.

It is known that in order to achieve both moldability and strength of the ethylene polymer, it is preferable to contain a component having a high MFR as described above. By using the ethylene polymerization method of the present invention, such losses during the production of ethylene polymer can be further reduced.

EXAMPLES Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.
In the following examples, the composition and particle size distribution of the solid titanium catalyst component for ethylene polymerization, the bulk specific gravity, MFR, NNI and particle size distribution of the ethylene polymer were measured as follows.

<Magnesium and titanium content>
It was measured by ICP analysis (Shimadzu Corporation, ICPF 1000TR).

<Chlorine content>
It was measured by the silver nitrate titration method.

<Alcohol residue content>
A sufficiently dried catalyst was added to an acetone solution containing 10% by weight of water, and the alcohol obtained by hydrolysis was quantified by gas chromatography.

<D50>
The D50 (median diameter) of the solid titanium catalyst component was determined using a laser particle size analyzer (Beckman Coulter LS13 320).

<SPAN>
SPAN, which is an index of particle size distribution, was obtained from the following formula using a laser particle size distribution analyzer (Beckman Coulter LS13 320).
SPAN=(D90-D10)/D50
D10: Particle diameter (μm) corresponding to 10% by volume
D50: Particle diameter (median diameter) corresponding to 50% by volume (μm)
D90: Particle diameter (μm) corresponding to 90% by volume

<Bulk specific gravity (BD)>
Measured according to JIS K-6721 standard.

<Melt flow rate (MFR)>
It was measured under conditions of 190° C. and a load of 2.16 kg according to ASTM D1238E.

<NNI>
NNI (Non Newton Index), which is an index of the molecular weight distribution of polyethylene, was determined from the ratio of shear rates at two specific shear stresses shown in the following formula in a molten state at 190°C.
NNI = γ2/γ1
γ1: shear rate at shear stress 4.0 x 10 ⁴ Pa (s ^-1 )
γ2: shear rate at shear stress 2.4 x 10 ⁵ Pa (s ^-1 )

<Fine powder content (particle size distribution)>
Using a vibrator (Iida Seisakusho, Rotap) and a sieve (Bunsei Furui, inner diameter 200 mm, mesh size 45 μm), the content of fine powder of less than 45 μm was measured.

[Example 1]
"Preparation of Solid Titanium Catalyst Components for Ethylene Polymerization"
2.50 g (26.2 mmol) of anhydrous magnesium chloride, 10.3 ml of decane and 12.3 g (94.3 mmol) of 2-ethylhexyl alcohol (EHA, 2-ethylhexanol) were heated at 140° C. for 4 hours to give a homogeneous reaction. After making a solution, 0.72 g (15.7 millimoles) of ethyl alcohol (EtOH, ethanol) was added, and the mixture was reacted by heating at 50° C. for 1 hour, and then slowly cooled to room temperature.

The entire amount of the homogeneous solution thus obtained was added dropwise to 100 ml of titanium tetrachloride at 20° C. over 45 minutes while stirring. The temperature during the dropping was kept at 20°C. After completion of charging, the temperature of this mixture was maintained at 20° C. for 1 hour and then raised to 110° C. over 90 minutes. When the temperature reached 110° C., 0.53 g (2.62 mmol, 0.10 molar ratio to Mg) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was added, followed by stirring for 15 minutes. After holding at the same temperature, filtration was performed at the same temperature to separate the solid portion. The solid portion was thoroughly washed with decane at 110° C. and then with hexane at room temperature until free titanium compounds were no longer detected to obtain a solid titanium catalyst component for ethylene polymerization (I-1).

The obtained solid titanium catalyst component (I-1) was stored as a decane suspension, but part of it was dried for analysis. Its composition is 6.1% by weight of titanium, 15% by weight of magnesium, 1.2% by weight of ethyl alcohol residue, 7.1% by weight of 2-ethylhexyl alcohol residue, 2-isopropyl-2-isobutyl-1,3- Dimethoxypropane was 11.3% by weight.
The resulting decane suspension of the solid titanium catalyst component (I-1) was measured with a laser particle size distribution analyzer to find a D50 of 2.7 μm and a SPAN of 0.85.

"polymerization"
In an autoclave having an internal volume of 1 liter, 500 ml of purified n-heptane was charged under an ethylene atmosphere, and 0.25 mmol of triethylaluminum and the solid titanium catalyst component for ethylene polymerization (I-1) obtained above were added. After adding the decane suspension in an amount equivalent to 0.005 mmol in terms of titanium atoms, the temperature was raised to 80 ° C., 0.3 MPa of hydrogen was supplied, and then ethylene was continuously supplied so that the gauge pressure was 0.6 MPa. Fed for 1.5 hours. The polymerization temperature was kept at 80°C.

After the polymerization was completed, the ethylene polymer was separated from the n-heptane solvent by filtration, washed and dried. After drying, 103.4 g of powdery polymer was obtained. This powdery polymer had an MFR of 3.4 g/10 minutes, an apparent bulk specific gravity of 0.28 g/ml, and an NNI of 22.

[Example 2]
"Preparation of Solid Titanium Catalyst Components for Ethylene Polymerization"
The amount of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane added was changed from 0.53 g (2.62 mmol) to 0.66 g (3.28 mmol, 0.125 molar ratio to Mg) A solid titanium catalyst component for ethylene polymerization (I-2) was obtained in the same manner as in Example 1 except for the above. Table 1 shows the results of measurement by a laser particle size distribution analyzer.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (I-2) was used. Table 2 shows the results.

[Example 3]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
The amount of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane added was changed from 0.53 g (2.62 mmol) to 0.80 g (3.93 mmol, 0.15 molar ratio to Mg). A solid titanium catalyst component for ethylene polymerization (I-3) was obtained in the same manner as in Example 1 except for the above. Table 1 shows the results of measurement by a laser particle size distribution analyzer.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (I-3) was used. Table 2 shows the results.

[Example 4]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
2.50 g (26.2 mmol) of anhydrous magnesium chloride, 10.3 ml of decane and 12.3 g (94.3 mmol) of 2-ethylhexyl alcohol (EHA) were heated at 140° C. for 4 hours to form a homogeneous solution. 0.72 g (15.7 mmol) of ethyl alcohol (EtOH) was added, and the mixture was reacted by heating at 50° C. for 1 hour, and then gradually cooled to room temperature.

The entire homogeneous solution thus obtained was added dropwise to 100 ml of titanium tetrachloride at 15° C. over 45 minutes while stirring. The temperature during the dropping was kept at 15°C. After completion of charging, the temperature of this mixture was maintained at 15° C. for 1 hour and then raised to 110° C. over 137 minutes. When the temperature reached 110° C., 0.53 g (2.62 mmol, 0.125 molar ratio to Mg) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was added, followed by stirring for 15 minutes. After holding at the same temperature, filtration was performed at the same temperature to separate the solid portion. The solid portion was thoroughly washed with decane at 110° C. and then with hexane at room temperature until free titanium compounds were no longer detected to obtain a solid titanium catalyst component for ethylene polymerization (I-4).

The obtained solid titanium catalyst component (I-4) was stored as a decane suspension, but part of it was dried for analysis. Its composition is 5.4% by weight of titanium, 16% by weight of magnesium, 1.1% by weight of ethyl alcohol residue, 5.9% by weight of 2-ethylhexyl alcohol residue, 2-isopropyl-2-isobutyl-1,3- Dimethoxypropane was 14.0% by weight.
The decane suspension of the obtained solid titanium catalyst component (I-4) was measured with a laser particle size distribution analyzer to find that D50 was 4.0 μm and SPAN was 1.15.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (I-4) was used. Table 2 shows the results.

[Example 5]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
2.50 g (26.2 mmol) of anhydrous magnesium chloride, 10.3 ml of decane and 12.3 g (94.3 mmol) of 2-ethylhexyl alcohol (EHA) were heated at 140° C. for 4 hours to form a homogeneous solution. After adding 0.97 g (21.0 mmol) of ethyl alcohol (EtOH) and reacting with heating at 50° C. for 1 hour, the mixture was gradually cooled to room temperature.

The entire homogeneous solution thus obtained was added dropwise to 100 ml of titanium tetrachloride at 10° C. over a period of 45 minutes while stirring. The temperature during the dropping was kept at 10°C. After completion of charging, the temperature of this mixture was maintained at 15° C. for 1 hour and then raised to 110° C. over 163 minutes. When the temperature reached 110° C., 0.53 g (2.62 mmol, 0.125 molar ratio to Mg) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was added, followed by stirring for 15 minutes. After holding at the same temperature, filtration was performed at the same temperature to separate the solid portion. The solid portion was thoroughly washed with decane at 110° C. and then with hexane at room temperature until free titanium compounds were no longer detected to obtain a solid titanium catalyst component for ethylene polymerization (I-5).

The obtained solid titanium catalyst component (I-5) was stored as a decane suspension, but part of it was dried for analysis. Its composition is 5.4% by weight of titanium, 16% by weight of magnesium, 1.2% by weight of ethyl alcohol residue, 5.7% by weight of 2-ethylhexyl alcohol residue, 2-isopropyl-2-isobutyl-1,3- Dimethoxypropane was 13.6% by weight.
When the obtained decane suspension of the solid titanium catalyst component (I-5) was measured with a laser particle size distribution analyzer, D50 was 3.2 μm and SPAN was 0.81.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (I-5) was used. Table 2 shows the results.

[Example 6]
"Preparation of Solid Titanium Catalyst Components for Ethylene Polymerization"
Solid titanium for ethylene polymerization was prepared in the same manner as in Example 5, except that the amount of ethyl alcohol (EtOH) added was changed from 0.97 g (21.0 mmol) to 1.21 g (26.2 mmol). A catalyst component (I-6) was obtained. Table 1 shows the results of measurement by a laser particle size distribution analyzer.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (I-6) was used. Table 2 shows the results.

[Comparative Example 1]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
2.50 g (26.2 mmol) of anhydrous magnesium chloride, 14.8 ml of decane and 8.53 g (65.5 mmol) of 2-ethylhexyl alcohol (EHA) were heated at 140° C. for 4 hours to form a homogeneous solution. 0.72 g (15.7 mmol) of ethyl alcohol (EtOH) and 0.66 g (3.28 mmol, 0.125 molar ratio to Mg) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane were mixed. After adding and reacting with heating at 50° C. for 1 hour, it was slowly cooled to room temperature.

The entire homogeneous solution thus obtained was added dropwise to 100 ml of titanium tetrachloride at 0° C. over 45 minutes while stirring. The temperature during the dropping was kept at 0°C. After the completion of charging, the temperature of this mixture was maintained at 0°C for 1 hour, then heated to 110°C over 217 minutes, then stirred for 15 minutes and maintained at the same temperature, and then filtered at the same temperature. , separated the solid part. The solid portion was thoroughly washed with decane at 110° C. and then with hexane at room temperature until free titanium compounds were no longer detected to obtain a solid titanium catalyst component for ethylene polymerization (C-1).

The obtained solid titanium catalyst component (C-1) was stored as a decane suspension, but part of it was dried for analysis. Its composition is 5.4% by weight of titanium, 15% by weight of magnesium, 1.3% by weight of ethyl alcohol residue, 5.9% by weight of 2-ethylhexyl alcohol residue, 2-isopropyl-2-isobutyl-1,3- Dimethoxypropane was 14.8% by weight.

When the obtained decane suspension of the solid titanium catalyst component (C-1) was measured with a laser particle size distribution analyzer, D50 was 4.3 μm and SPAN was 3.17.
As described above, since the SPAN value is relatively large in Comparative Example 1, there is a possibility that fine powder and solvent-soluble components cannot be sufficiently reduced when used for plant operation.

[Comparative Example 2]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
2.50 g (26.2 mmol) of anhydrous magnesium chloride, 10.3 ml of decane and 12.3 g (94.3 mmol) of 2-ethylhexyl alcohol (EHA) were heated at 140° C. for 4 hours to form a homogeneous solution. 0.72 g (15.7 mmol) of ethyl alcohol (EtOH) and 0.27 g (1.31 mmol, 0.05 molar ratio to Mg) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane were mixed. After adding and reacting with heating at 50° C. for 1 hour, it was slowly cooled to room temperature.

The entire amount of the homogeneous solution thus obtained was added dropwise to 100 ml of titanium tetrachloride at 20° C. over 45 minutes while stirring. The temperature during the dropping was kept at 20°C. After completion of charging, the temperature of this mixed solution was maintained at 20°C for 1 hour, then heated to 110°C over 1 hour and 30 minutes, then stirred for 15 minutes and maintained at the same temperature, and then filtered at the same temperature. was performed to separate the solid portion. The solid portion was thoroughly washed with decane at 110° C. and then with hexane at room temperature until free titanium compounds were no longer detected to obtain a solid titanium catalyst component for ethylene polymerization (C-2).

The obtained solid titanium catalyst component (C-2) was stored as a decane suspension, but part of it was dried for analysis. Its composition is 7.9% by weight of titanium, 13% by weight of magnesium, 1.6% by weight of ethyl alcohol residue, 11.8% by weight of 2-ethylhexyl alcohol residue, 2-isopropyl-2-isobutyl-1,3- Dimethoxypropane was 5.2% by weight.
When the obtained decane suspension of the solid titanium catalyst component (C-2) was measured with a laser particle size distribution analyzer, D50 was 3.3 μm and SPAN was 0.82.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (C-2) was used. Table 2 shows the results.
The result of Comparative Example 2 was that the NNI value was high and the molecular weight distribution was slightly wide.

[Comparative Example 3]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
The amount of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane added was changed from 0.27 g (1.31 mmol) to 0.53 g (2.62 mmol, 0.10 molar ratio to Mg). Other than that, it was carried out in the same manner as in Comparative Example 2. As a result, the particles did not grow to a sufficient size, and all the solid portion flowed out to the filtrate side during filtration, making it impossible to obtain a solid titanium catalyst component for ethylene polymerization.

[Comparative Example 4]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
A solid titanium catalyst component for ethylene polymerization (C- 3) was obtained. Table 1 shows the results of measurement by a laser particle size distribution analyzer.
As described above, since the SPAN value is relatively large in Comparative Example 4, there is a possibility that fine powder and solvent-soluble components cannot be sufficiently reduced when used for plant operation.

[Comparative Example 5]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
A solid titanium catalyst component for ethylene polymerization (C-4) was obtained in the same manner as in Example 1, except that 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was not added. Table 1 shows the results of measurement by a laser particle size distribution analyzer.
As described above, since the SPAN value is relatively large in Comparative Example 5, there is a possibility that fine powder and solvent-soluble components cannot be sufficiently reduced when used for plant operation.

[Comparative Example 6]
"Preparation of Solid Titanium Catalyst Component for Ethylene Polymerization"
The amount of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane added was changed from 0.53 g (2.62 mmol) to 1.06 g (5.24 mmol, 0.20 molar ratio to Mg). A solid titanium catalyst component for ethylene polymerization (C-7) was obtained in the same manner as in Example 1 except for this. Table 1 shows the results of measurement by a laser particle size distribution analyzer.

"polymerization"
Ethylene was polymerized in the same manner as in Example 1, except that the solid titanium catalyst component for ethylene polymerization (C-7) was used. Table 2 shows the results.
Comparative Example 6 resulted in low activity and high bulk specific gravity.

Claims (7)

(1) a liquid magnesium compound (A) containing a magnesium compound, an electron donor having 1 to 5 carbon atoms (a), and an electron donor having 6 to 30 carbon atoms (b);
a liquid titanium compound (C),
Without using the electron donor (B1), or in the presence of the electron donor (B1) when using the electron donor (B1), the magnesium atom (Mg) contained in the liquid magnesium compound (A) and the electron donor (B1) molar ratio [(B1)/(Mg)] to the body (B1) is 0.04 or less, contacting at -30 to 50 ° C. to obtain a contact material; and (2) the contact material and the electron donor (B2), wherein the molar ratio [(B2)/(AC)] of the magnesium atom (AC) contained in the contact material and the electron donor (B2) is 0.05 to 0.19. and contacting under conditions of 85 to 135 ° C;
A method for producing a solid titanium catalyst component (I) for ethylene polymerization containing titanium, magnesium and halogen, having The molar ratio [(a)/(b)] between the amount of the electron donor (a) used and the amount of the electron donor (b) used is less than 1, and the electron donor (a), The solid titanium catalyst component for ethylene polymerization according to claim 1, wherein the electron donor (b), the electron donor (B1) and the electron donor (B2) are heteroatom-containing compounds excluding cyclic ether compounds. (I) production method. the electron donor (a) is an alcohol having 1 to 5 carbon atoms,
3. The method for producing a solid titanium catalyst component (I) for ethylene polymerization according to claim 1 or 2, wherein the electron donor (b) is an alcohol having 6 to 12 carbon atoms. The method for producing a solid titanium catalyst component (I) for ethylene polymerization according to any one of claims 1 to 3, wherein the electron donors (B1) and/or (B2) contain polyethers. 5. The method for producing a solid titanium catalyst component (I) for ethylene polymerization according to claim 4, wherein the electron donor (B1) and/or (B2) contains a compound represented by the following formula (b1).

[In the formula (b1), m is an integer of 1 to 10, and R ¹¹ , R ¹² , R ³¹ to R ³⁶ are each independently a hydrogen atom, or carbon, hydrogen, oxygen, fluorine, chlorine, bromine, A substituent having at least one element selected from iodine, nitrogen, sulfur, phosphorus, boron and silicon. Arbitrary R ¹¹ , R ¹² , R ³¹ to R ³⁶ may jointly form a ring other than a benzene ring, and may contain an atom other than carbon in the main chain. ] An ethylene polymerization solid titanium catalyst component (I) is obtained by the production method according to any one of claims 1 to 5, and the ethylene polymerization solid titanium catalyst component (I) and an organometallic compound catalyst component (II) are produced. ) and a method for producing an ethylene polymerization catalyst. A method for polymerizing ethylene, comprising obtaining an ethylene polymerization catalyst by the method for producing an ethylene polymerization catalyst according to claim 6, and performing homopolymerization of ethylene or copolymerization of ethylene with another olefin in the presence of the catalyst.