JPH06279529A - Production of ethylene polymer - Google Patents

Abstract

PURPOSE:To produce a deashing-free ethylene polymer by using a catalyst which is highly active and can produce an ethylene polymer having a very narrow molecular weight distribution or an ethylene/alpha-olefin copolymer reduced in the content of polymers of very low molecular weights. CONSTITUTION:An ethylene polymer is produced by using a catalyst comprising a solid catalyst component, obtained by a reaction by contact among a magnesium compound, a titanium compound and an electron-donating compound (ED) and having a titanium content of 3-6wt.% and an ED/titanium molar ratio of 0.3-0.8, and an organoaluminum compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an ethylene polymer having an extremely narrow molecular weight distribution. More specifically, by using a novel catalyst system having excellent polymerization activity, homopolymerization of ethylene or copolymerization of ethylene with other olefins produces an ethylene-based polymer with high activity and extremely narrow molecular weight distribution. It relates to a method of manufacturing.

[0002]

2. Description of the Related Art Conventionally, many methods for producing an ethylene polymer having a relatively narrow molecular weight distribution and suitable for injection molding have been proposed. Among them, a catalyst system having a narrow molecular weight distribution is used. It is known that even in a polymer obtained by homopolymerizing ethylene, a large amount of extractables (extremely low molecular weight polymer) exists when extraction is performed using a solvent (for example, n-hexane). .

The presence of these extremely low molecular weight polymers causes fouling and bridging in the production of the polymer, and also causes smoke, smoke and odor when the polymer is molded. These phenomena are due to ethylene and other α
-Notable in the production of copolymers obtained by copolymerizing with olefins and in the molding of such copolymers, especially n- in the production of medium and low density polyethylene.
The amount of extraction with the hexane solvent increases. The extract in this case is mainly composed of an extremely low molecular weight polymer,
The density distribution (branching degree distribution) of the copolymer is determined by the amount of the extremely low molecular weight polymer present. Therefore, in the conventional polyethylene, the very low molecular weight polymer components of the polymer are extracted and the components are removed in terms of process.

In recent years, magnesium compounds, titanium halides and electron donating compounds (hereinafter referred to as ED).
Highly active high-performance polymerization catalyst system capable of obtaining a polymer with high stereoregularity when an olefin is polymerized by using a catalyst composed of a solid catalyst component obtained by catalytically reacting benzene, an organoaluminum compound and a compound to be an external ED Is being developed.

For example, in JP-A-60-23404 and JP-A-60-44507, dialkoxymagnesium suspended in a halogenated hydrocarbon is subjected to a catalytic reaction with an aromatic dicarboxylic acid diester and a titanium halogen compound. It is disclosed that a polypropylene having high stereoregularity can be obtained with high activity by the solid catalyst component obtained as described above.

However, according to the studies by the present inventors, in the polymerization of ethylene, there was a problem in that sufficient activity could not be obtained if an attempt was made to obtain a polymer having a narrow molecular weight distribution.

Further, as a technique for reducing the production amount of an extremely low molecular weight polymer, JP-B-56-39766 and JP-B-59-
1408, JP 59-1409, JP 63-2
Although proposals such as No. 18709 have been made, it is hard to say that any of them has sufficiently suppressed generation of an extremely low molecular weight polymer.

[0008]

The present invention is highly active, has an extremely narrow molecular weight distribution, and produces a very low molecular weight polymer even when it is copolymerized with other α-olefins. The purpose of the present invention is to develop a method for producing a so-called non-deashed ethylene-based polymer that does not require removal of catalyst residues.

[0009]

The present invention provides (a) a solid catalyst component obtained by catalytically reacting a magnesium compound, a titanium compound and an electron-donating compound, wherein the amount of titanium supported in the component is 3 to. 6% by weight, and a solid catalyst component having a molar ratio (ED / titanium) of the supported electron donating compound (ED) to the amount of supported titanium of 0.3 to 0.8 and (b) an organoaluminum compound. The above object was achieved by developing a method for producing an ethylene-based polymer characterized by using a catalyst.

Examples of the magnesium compound used for producing the solid catalyst component of the present invention include magnesium alcoholate, magnesium halide, magnesium fatty acid and the like. Among them, magnesium alcoholate is represented by the general formula (I). Mg (OR ¹ ) ₂ (I)

In the formula (I), R ¹ is selected from the group consisting of an alkyl group having at most 8 carbon atoms, a cycloalkyl group, a cycloalkyl group having an alkyl group, an aryl group and an aralkyl group. It is a hydrocarbon group.

These magnesium alcoholates are obtained by reacting magnesium with a lower alcohol (for example, methyl alcohol, ethyl alcohol), and magnesium alcoholates substituted by the reaction of these magnesium alcoholates with higher alcohols and phenols. And their manufacturing methods are well known.

Typical of these magnesium alcoholates are magnesium methylate, magnesium ethylate, magnesium-n-propylate, magnesium isopropylate, magnesium butyrate, magnesium hexylate, phenoxymagnesium, magnesium benzylate and the like. Alcoholate and magnesium credol. Among these magnesium alcoholates, those represented by the general formula (I) in which R ′ is preferably an alkyl group having at most 3 carbon atoms or a phenyl group are preferable.

The magnesium halide is most preferably magnesium chloride. Further, as the fatty acid magnesium, saturated fatty acid magnesium is preferable, and magnesium stearate, magnesium octanoate, magnesium decanoate and magnesium laurate are particularly preferable.

The ED used in the production of the solid catalyst component may be benzoic acid esters, but generally diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, di-n.
-Aromatic dicarboxylic acid esters such as diethyl octylnaphthalene dicarboxylate and dibutyl naphthalene dicarboxylate, and alkoxyesters, typically 3
-Ethoxy ethoxy 2-tolyl propionate, 3-ethoxy 3-tert-butyl ethyl propionate, 2-te
From the viewpoint of effects, rt-butyl butyl propionate and the like are preferable.

Solvents used for preparing the solid catalyst component include aromatic hydrocarbon compounds (eg, benzene, toluene, xylene) and hydrocarbon halides (eg, methylene chloride, dichloroethane, carbon tetrachloride, trichloroethane). And mixtures thereof. In particular, those having a boiling point of 30 to 150 ° C. are desirable, and among them, methylene chloride and toluene are most suitable.

The titanium compounds used in the present invention include titanium tetrachloride, titanium trichloride, and other halogenated titanium; titanium butoxide, titanium isopropoxide, titanium ethoxide, and other halogen-substituted titanium alkoxides;
Examples thereof include phenoxy titanium chloride and other alkoxy titanium halides. Also, a mixture of two or more of these compounds may be used. A tetravalent titanium compound containing halogen is preferable, and titanium tetrachloride is particularly preferable.

A feature of the present invention is the composition in the solid catalyst component. Titanium, magnesium, ED in solid catalyst component
The composition of titanium is 3 to 6 wt% and magnesium is 5 to 20.
wt%, ED10 to 20 wt%, preferably 5 to 8 wt% magnesium, and ED14 to 16 wt%.
The ED / titanium molar ratio is 0.3 to 0.8.

That is, if it deviates from this range, there is a phenomenon that the polymerization activity is remarkably lowered and the molecular weight distribution is broadened.

These solid catalyst components are obtained by previously suspending a magnesium compound and ED in the above-mentioned inert solvent,
2 to 10 times mol of magnesium, preferably 4 to 5
This can be done by adding a double mole of titanium tetrachloride. Especially E
The change of the D / titanium ratio can be easily achieved by changing the mixing ratio of ED with respect to the magnesium compound.

In order to obtain the solid catalyst component, the respective raw materials forming the component may be mixed together and reacted by heating, but preferably the magnesium compound, ED and the solvent are mixed at 0-100 ° C. for 0. After reacting for 2 to 2.5 hours, titanium halide is added thereto, and the mixture is added at -50 to 150 ° C. to 1.0.
It can be obtained by reacting for ~ 2.5 hours and washing the obtained reaction product until halogen is no longer detected.

As the organoaluminum compound used in the polymerization together with the solid catalyst component, an organoaluminum compound represented by the general formula AlR ² _r X _3-r (II) is used. (I
In formula (I), R ² is an aliphatic, alicyclic or aromatic hydrocarbon group having at most 12 carbon atoms, X is a halogen atom or a hydrogen atom, and r is a number of 2 or 3. is there. Typical examples are triethyl aluminum, triisobutyl aluminum, trihexyl aluminum,
Examples thereof include diethylaluminum hydride and diethylaluminum chloride.

The mixing ratio of the organoaluminum compound to the solid catalyst component varies depending on the bench test, pilot plant, main plant, etc., but the molar ratio of aluminum / titanium is about 20 to 50. When the catalyst is charged, isobutane is used as the solvent. In doing so, the aluminum concentration is about 0.5 to 1.25 mmol / l as a guide.

The raw material monomers used in the present invention differ depending on the product to be processed, such as high density polyethylene, medium density polyethylene, linear low density polyethylene, etc.
To obtain high-density polyethylene, ethylene is used alone. To obtain medium-density polyethylene, linear low-density polyethylene, etc., ethylene is copolymerized with a small amount of α-olefin.

As the α-olefin copolymerizable with ethylene, propylene, butene-1, hexene-1,4-methylpentene-1, vinylcyclohexene, octene-1.
And unsaturated hydrocarbons having 3 to 15 carbon atoms such as styrene, but generally propylene, butene-1, hexene-1.
Alternatively, it is 4-methylpentene-1. The proportion of the above α-olefin in the obtained ethylene polymer is generally preferably 20 mol% or less, and particularly preferably 15 mol or less.

Polymerization can be carried out in the presence or absence of an organic solvent without changing from the usual conditions for high- and medium-density polyethylene, and the olefin monomer is used in either gas or liquid state. be able to. The polymerization temperature is room temperature to 300 ° C., preferably 100 ° C. or less, the polymerization pressure is 1 to 200 kg / cm ² · G, preferably 50 kg / cm ² · G or less, and the gas phase method, slurry method or solution method is used. It can be carried out.

[0027]

[Effect] The reason why the catalyst of the present invention is highly active in producing an ethylene polymer, the obtained polymer has a narrow molecular weight distribution, and the production ratio of an extremely low molecular weight polymer is small can be clarified. There wasn't.

Although the catalyst system can be used as it is to produce a polymer having a sufficiently narrow molecular weight distribution, tetramethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, tetraethoxysilane, triethoxyethylsilane, ethoxytriethyl can be prepared. When a silicon compound such as silane, tetrapropoxysilane, dipropoxydipropylsilane, tetraisopropoxysilane, diisopropoxydiisopropylsilane, dimethyldiethylsilane or diethoxydibutylsilane is used in combination, the polymerization activity is slightly lowered, but A polymer having a narrow molecular weight distribution can be obtained. Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

[0029]

【Example】

(Example 1) (1) Production of solid catalyst component A 200 ml three-necked flask equipped with a thermometer and a stirrer was sufficiently replaced with nitrogen, and diethoxymagnesium 1.
11 g, 10 ml of toluene and 0.46 ml of di-n-butyl phthalate as ED are added, and the mixture is reacted at 70 ° C. for 1 hour. Then, titanium tetrachloride in a state of stirring at 70 ° C. 4.
Quickly add 8 ml. Next, set the temperature in the flask to 11
The temperature is raised to 0 ° C. and the reaction is performed for 2 hours. After the reaction, the mixture was cooled to room temperature, washed several times with 200 ml of n-hexane, the supernatant was removed and washed with warm water of 50 to 60 ° C., and then 20 to 60.
The solid was dried under reduced pressure for a minute to obtain a solid catalyst component. The amount of supported titanium in the obtained solid catalyst component was 4.0 wt% and the molar ratio of ED / titanium was 0.6.

(2) Polymerization of ethylene A fully dried solid catalyst component obtained by the above method was placed in a 1.2 L autoclave, which had been sufficiently replaced with nitrogen, by 11.4 m.
1.5 ml (149 mg) of a 0.5 mol / l pentane solution of g and triisobutylaluminum, isobutane 60
0 ml of hydrogen and 2.5 kg / cm ² · G of hydrogen were charged, the internal temperature of the autoclave was raised to 90 ° C., and the pressure was increased until the partial pressure of ethylene became 5 kg / cm ² · G to start the polymerization. Then, polymerization was carried out for 1 hour while maintaining the ethylene partial pressure at 5 kg / cm ² · G, and the polymerization was terminated by releasing the gas other than the polymer from the autoclave to the outside. As a result, a white powdery polymer was obtained. was gotten.

The obtained polymer was 114 g, and the polymerization activity was 2000 g / g solid catalyst / hour / ethylene partial pressure. The boiling normal n-hexane extraction amount as an index of the extremely low molecular weight polymer and the extremely low density polymer is 0.16 wt%.
And it is clear that the amount of production is small.

The density of the obtained polymer 0.95 g / cc,
Melt flow rate (JIS K-7210, test condition 4 in Table 1; test temperature 190 ° C., test load 2.16 kg
f, hereinafter referred to as MFR. ) Is 1.80 g / 10 minutes, and high load melt index (JIS K-72
10, test condition 7 in Table 1; 190 ° C., 21.6 kgf,
Hereinafter referred to as HLMI. ) Was 37.3 g / 10 minutes. Their ratio, HLMI / MFR, was 20.7, and the molecular weight distribution was extremely narrow.

(Example 2) Polymerization was carried out under the same conditions as in Example 1 except that 10.9 mg of the solid catalyst component obtained in Example 1 was used and 40 g of hexene-1 was injected as a comonomer during the polymerization. went. As a result, the polymerization activity is 2
300 g / g solid catalyst, time, ethylene partial pressure, density of the obtained polymer 0.92, MFR 0.73 g / 1
At 0 minutes, HLMI / MFR was 22.4, and a copolymer having a narrow molecular weight distribution was obtained even when used as a copolymer.
In addition, the amount of boiling normal hexane extracted was 1.02 wt%, even though hexene-1 was copolymerized, and the amount of the copolymer was suppressed to a small amount.

(Example 3) The conditions for producing the solid catalyst component and the polymerization of ethylene were the same as in Example 1 except that 0.26 ml of di-n-butyl phthalate was used as the ED in Example 1. . The amount of titanium supported in the solid catalyst component was 4.0 wt%, the molar ratio of ED / titanium was 0.4,
The polymerization activity was 2500 g / g solid catalyst / time / ethylene partial pressure, and the density of the obtained polymer was 0.95 g / cc.
MFR 0.50 g / 10 minutes, HLMI / MFR = 21.
It was 2, and the molecular weight distribution was extremely narrow. The boiling normal hexane extraction is 0.20 wt%,
It is clear that the production of extremely low molecular weight polymers and the like is small.

Example 4 A solid catalyst component was prepared under exactly the same conditions as in the production of the solid catalyst of Example 1, except that diethoxymagnesium was used as the magnesium compound instead of equimolar magnesium chloride. The amount of titanium supported on the obtained solid catalyst component was 4.6 wt%, and the molar ratio of ED / titanium was 0.4. Using this solid catalyst component,
Polymerization of ethylene was carried out under the same conditions as in Example 1.
The obtained polymer was 228 g, and the polymerization activity was 1590.
It was g / g solid catalyst / time / ethylene partial pressure. Also,
Polymer MFR 1.02g / 10min, HLMI 2
It was 4.3 g / 10 minutes, HLMI / MFR was 23.8, and boiling normal hexane extraction amount was 0.3 wt%.

Example 5 (1) Production of solid catalyst component A 200 ml three-necked flask equipped with a thermometer and a stirrer was sufficiently replaced with nitrogen, and 1.19 g of diethoxymagnesium and 5 parts of 1,2-dichloropropane were added thereto. .9 ml and 3
Ethyl 3-ethoxy-3-t-butylpropionate 0.42
Add g and react at 70 ° C. for 1 hour. Then, 4.9 ml of titanium tetrachloride is quickly added at 70 ° C. with stirring. Next, the temperature in the flask is raised to 110 ° C. and the reaction is performed for 2 hours. After the reaction, the mixture was cooled to room temperature, washed several times with 200 ml of n-hexane, the supernatant was removed, washed with warm water of 50 to 60 ° C. for 20 to 60 minutes, and dried under reduced pressure to obtain a solid catalyst component. The amount of supported titanium in the obtained solid catalyst component was 4.3 wt% and the molar ratio of ED / titanium was 0.6.

(2) Polymerization Polymerization was carried out under the same conditions as in Example 1. The amount of the polymer obtained was 100 g, and the polymerization activity was 847 g / g solid catalyst / hour / ethylene partial pressure. Also, the MFR of this polymer
Is 0.52 g / 10 minutes, HLMI is 9.9 g / 1
It was 0 minutes. Their ratio, HLMI / MFR, is 2
0.5, boiling normal hexane extraction is 0.16 wt%
The molecular weight distribution was extremely narrow.

(Example 6) A 200 ml three-necked flask equipped with a thermometer and a stirrer was sufficiently replaced with nitrogen, and 1.11 g of diethoxymagnesium, 10 ml of methylene chloride and 0-di-n-butylphthalate as ED were added. ．
Add 46 ml and reflux for 1 hour. Then 1
Quickly add 4.8 ml of titanium tetrachloride under stirring at 0 ° C. Next, the temperature in the flask is raised to 110 ° C. and the reaction is performed for 2 hours. After the reaction, the mixture was cooled to room temperature and 200 ml of n-
After washing several times with hexane, the supernatant was removed and the mixture was washed with warm water at 50 to 60 ° C. for 20 to 60 minutes and then dried under reduced pressure to obtain a solid catalyst component. The amount of titanium supported in the obtained solid catalyst component was 5.0% by weight, and the molar ratio of ED / titanium was 0.6. Polymerization similar to Example 1 was performed using the obtained solid catalyst. The polymerization activity was 2900 g / g solid catalyst / time / ethylene partial pressure, and the MFR of the obtained polymer was 0.
It was 84 g / 10 minutes, HLMI / MFR was 22.3, and boiling normal hexane extraction amount was 0.22 wt%.

Example 7 In the ethylene polymerization of Example 1, 0.1 mol /% of diisopropyldimethoxysilane was used.
It was carried out by adding 0.6 ml (10.6 mg) of 1 hexane solution. As a result, the polymerization activity was 1100 g /
g solid catalyst, time, ethylene partial pressure, the density of the obtained polymer was 0.95 g / cc, MFR 1.20 g / 10
Min, HLMI was 23.7 g / 10 min, their ratio, HLMI / MFR was 19.7, and the boiling normal hexane extraction amount was 0.15 wt%. Although the polymerization activity was reduced to about half, a polymer having a narrower molecular weight distribution was obtained.

(Example 8) 0.1 mol of diisopropyldimethoxysilane was added to the solid catalyst component obtained in Example 6
Polymerization was carried out under the same conditions as in Example 6 except that 0.6 ml (10.6 mg) of 1 hexane solution was added. Polymerization activity was 2190 g / g solid catalyst / time / ethylene partial pressure, MFR of the obtained polymer was 0.72 g / 10 min, H
The LMI / MFR was 20.5, and the boiling normal hexane extraction amount was 0.16 wt%.

(Comparative Example 1) The same procedure as in Example 1 was repeated except that 0.52 ml of di-n-butyl phthalate and 1.6 ml of titanium tetrachloride were used as ED in the production of the solid catalyst component in Example 1. The production of the components and the reaction of ethylene polymerization were carried out. The amount of titanium supported in the obtained solid catalyst component was 1.0 wt% and the ED / titanium molar ratio was 1.
It was 8. The polymerization activity of the catalyst using this is 150 g /
g solid catalyst / time / ethylene partial pressure, the density of the obtained polymer was 0.95 g / cc, MFR 0.1 g / 10
Min, HLMI / MFR = 22.3, the boiling normal hexane extraction amount was 0.23 wt%. It is clear that the polymerization activity is extremely reduced.

(Comparative Example 2) In the same manner as in Example 1, except that 0.78 ml of di-n-butyl phthalate and 5.4 ml of titanium tetrachloride were used as ED in the production of the solid catalyst component in Example 1. The production of the catalyst component and the ethylene polymerization reaction were carried out. The amount of supported titanium in the obtained solid catalyst component was 5.5% by weight, and the ED / titanium molar ratio was 1.5. The polymerization activity of the catalyst using this is 400
g / g solid catalyst / time / ethylene partial pressure, the density of the obtained polymer was 0.95 g / cc, MFR 0.46 g /
After 10 minutes, HLMI / MFR = 23.0 and boiling normal hexane extraction amount was 0.25 wt%. The molecular weight distribution was broad and the polymerization activity was low.

(Comparative Example 3) In the same manner as in Example 1, except that 0.25 ml of di-n-butyl phthalate and 10.7 ml of titanium tetrachloride were used as ED in the production of the solid catalyst component in Example 1. The production of the catalyst component and the ethylene polymerization reaction were carried out. The amount of supported titanium in the obtained solid catalyst component was 1.9 wt%, and the ED / titanium molar ratio was 0.2. The polymerization activity of the catalyst using this is 290
0 g / g solid catalyst, time, ethylene partial pressure, the density of the obtained polymer was 0.95 g / cc, MFR 0.5 g /
10 minutes, HLMI / MFR = 28.0, boiling normal hexane extraction amount was 0.54 wt%. The polymerization activity of the catalyst was sufficiently high, but the molecular weight distribution was wide, and the boiling normal n-hexane extraction amount was large, which included problems such as fuming, smoke and odor.

(Comparative Example 4) A solid was prepared in the same manner as in Example 1 except that 0.52 ml of di-n-butyl phthalate and 1.8 ml of titanium tetrachloride were used as ED in the production of the solid catalyst component in Example 1. The production of the catalyst component and the ethylene polymerization reaction were carried out. The amount of titanium supported in the obtained solid catalyst component was 2.0 wt% and the ED / titanium molar ratio was 0.9. The polymerization activity of the catalyst using this is 200
g / g solid catalyst / time / ethylene partial pressure, the density of the obtained polymer was 0.95 g / cc, MFR 0.5 g / 1
At 0 minutes, HLMI / MFR = 20.7, the boiling normal hexane extraction amount was 0.18 wt%. The molecular weight distribution and the normal hexane extraction amount were small, and a preferable polymer was obtained, but the polymerization activity was extremely low.

Comparative Example 5 (1) Production of Solid Catalyst Component 1.0 g of diethoxymagnesium, 0.3 g of dipropyl phthalate and 10 ml of methylene chloride were placed in a flask, reacted for 1 hour under reflux, and then 40 ml of tetrachloride. The reaction product was pressed into titanium and further reacted at 90 ° C. for 2 hours. After cooling, the precipitated solid component was washed with 40 ° C. n-heptane, and 40 ml of titanium tetrachloride was newly added to the solid component.
The reaction was carried out at ℃ for 2 hours. After cooling, it was washed several times with n-heptane at 40 ° C. and dried under reduced pressure to obtain a solid catalyst component. The amount of titanium supported in the obtained solid catalyst component was 2.7 wt%, and ED /
The titanium molar ratio was 1.2.

(2) Polymerization of ethylene Polymerization was carried out under the same conditions as in Example 1 except that 28.3 mg of the above-mentioned solid catalyst component was used and 1.2 kg / cm ² of hydrogen was used. A polymer was obtained.
The polymerization activity of this catalyst was 280 g / g solid catalyst / time / ethylene partial pressure, and the density of the obtained polymer was 0.95 g.
/ Cc, MFR is 0.18 g / 10 minutes, HLMI is 4.
0 g / 10 min, their ratio HLMI / MFR = 22.
2. The boiling normal hexane extraction amount was 0.23.
Regardless of the molecular weight distribution and the amount of hexane extracted, the polymerization activity was insufficient. The results of Examples and Comparative Examples are shown in Table 1.

[0047]

[Table 1]

[0048]

The catalyst used in the production of the ethylene-based polymer of the present invention has a simple and easy operation for the production of the solid catalyst component as the core, and the catalyst prepared using this has a large polymerization activity. It can be used as a so-called non-deashing catalyst. The ethylene-based polymer obtained by using this polymer has a narrow molecular weight distribution, and the polymer can be produced with a preferable performance with a small amount of solvent extraction such as an extremely low molecular weight polymer that causes smoke, smoke and odor.

Further, ethylene alone or ethylene and other α
-High density polyethylene, medium density polyethylene, or linear low density polyethylene can be optionally produced by combining with an olefin.

[Brief description of drawings]

FIG. 1 is a flow chart showing a typical example of a process for preparing a catalyst component of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Minoru Oita-shi, Oita, Nakanosu, Showa Denko Co., Ltd. Oita Research Institute (72) Inventor Shintaro Inazawa, Oita, Oita, Japan 2 Showa Denko Co., Ltd. Oita Research In-house

Claims (1)

[Claims] 1. A solid catalyst component (a) obtained by catalytically reacting a magnesium compound, a titanium compound and an electron donating compound, wherein the amount of titanium supported in the component is 3 to 6.
From (b) an organoaluminum compound and a solid catalyst component having a molar ratio (ED / titanium) of the supported electron donating compound (ED) to the amount of supported titanium of 0.3 to 0.8% by weight. A method for producing an ethylene-based polymer, which comprises using the following catalyst.