JPH0625351A - Method for producing polyethylene - Google Patents

Abstract

(57) [Summary] [Structure] In the presence of a catalyst composed of a transition metal compound and an organometallic compound, ethylene is polymerized at a reaction temperature higher than the melting point of the polymer, or ethylene and at least one α-olefin are copolymerized. In this regard, as the (A) component,
A solid catalyst component obtained by contacting (I) oxygen-containing organomagnesium and / or magnesium halide, (II) titanium halide and (III) carbon halide compound, and an organoaluminum compound as (B) component A method for producing a polyolefin, which comprises using a catalyst system. [Effect] To provide a catalyst system composed of two components which is highly active, has excellent α-olefin reactivity, can control the branching degree distribution of the obtained polyethylene, and is not complicated in practical use.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polyethylene with a novel catalyst. More specifically, the present invention relates to a method for producing polyethylene, which comprises polymerizing ethylene or copolymerizing ethylene and an α-olefin using a novel catalyst having a high catalytic activity under a temperature above the melting point of polyethylene.

[0002]

2. Description of the Related Art Generally, a polymer of ethylene or ethylene-α-polymerized by a so-called Ziegler type catalyst, which is composed of two components of a transition metal compound and an organometallic compound.
The olefin copolymer is usually 0.880 to 0.975 g.
It has a wide density of / cm ³ and is used for a wide range of applications such as films and molded products.

As a method of polymerizing ethylene at a temperature above the melting point of polyethylene using this Ziegler type catalyst, a solution polymerization method and a high temperature and high pressure polymerization method are known. These polymerization methods are energy-efficient because it is possible to maintain the high temperature of the polymerization vessel by effectively utilizing the heat of polymerization, which is an exothermic reaction, and to save power for pelletizing the produced polymer.

In addition, in the solution polymerization method which is generally carried out in an inert solvent, the higher the polymerization temperature is, the lower the solution viscosity and the easier removal of the heat of polymerization are. Similarly in the high temperature and high pressure method, the larger the temperature difference between the polymerization temperature and the feedstock,
The higher the polymerization temperature, the better the conversion of ethylene,
Greater economic benefits. However, in the polymerization in these high temperature regions, generally, the catalyst activity and the activity sustainability are lowered by raising the polymerization temperature. If the catalyst activity is low, the amount of catalyst residue in the polymer is large, which has a drawback that it is likely to cause corrosion of process equipment, coloring of the polymer, and generation of gel.

In order to improve this, many proposals have already been made as catalysts that can be used for high temperature polymerization. For example, a catalyst system in which a titanium halide, a magnesium compound containing a halogen group and an organomagnesium compound are combined is disclosed in Japanese Patent Application Laid-Open No. 52-103485.
However, it cannot be said that the catalyst activity is satisfactory in this catalyst system, and further improvement of the catalyst activity is desired. Further, JP-A-62-84105 proposes a catalyst system in which a solid catalyst component obtained by co-milling a magnesium dihalide, a boron compound, a polysiloxane and a titanium tetrahalide compound is combined with an organic aluminum compound.
Although there is some improvement in catalytic activity, it is still not sufficient.

Further, in JP-A-60-262803, a solid catalyst containing a transition metal compound, organoaluminum,
A catalyst system composed of three components of a chlorinated organic compound has been proposed. There is some improvement in catalytic activity, but it is still insufficient. Furthermore, since it is a catalyst system consisting of three components, in practice, compared to the conventional catalyst system consisting of two components, the complexity of catalyst supply facility modification and polymerization control increases, and the conventional Ziegler type catalyst consisting of two components Improvement is required.

On the other hand, the basic physical properties of the copolymer obtained by the copolymerization of ethylene and α-olefin are determined by the amount and distribution of α-olefin introduced into the ethylene chain. That is, the number and distribution of short chain branches due to the α-olefin have a great influence on the basic properties of the polymer such as crystallinity, crystallization rate, spherulite structure and melting point. In addition, from the viewpoint of practical physical properties, environmental stress resistance, film strength, flexibility, moldability, and other aspects are affected.

From the above, it is very important to control the number of short chain branches and the distribution thereof in the copolymer in order to improve practical physical properties.

The distribution of short chain branches in the copolymer (hereinafter referred to as the degree of branching distribution) is greatly influenced by factors depending on the characteristics of the catalytically active species. Of an ethylene-α-olefin copolymer obtained by a catalyst system such as an organoaluminum compound (eg, trialkylaluminum) -titanium trichloride system and an organoaluminum compound-titanium tetrachloride system which have been conventionally used. Regarding the distribution of the degree of branching, it was impossible to significantly change the basic properties of the polymer such as melting point and crystallization rate because the control method was not clear.

Further, the reactivity of the α-olefin in the copolymerization seems to be closely related to the distribution of the degree of branching. Especially, in the case of the copolymerization with the α-olefin having 4 or more carbon atoms, the α-olefin has a The degree of conversion of olefins occupies a large proportion in the production cost.

However, when the performance of the above-mentioned prior art catalyst system was examined as a copolymerization catalyst of ethylene and α-olefin, controllability of the distribution of branching degree of the obtained polymer and reactivity with α-olefin were examined. However, the development of a method for controlling the copolymerization performance of these is strongly desired.

On the other hand, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 3-20
No. 7705, a catalyst system comprising a combination of a solid catalyst component treated with titanium halide after co-milling a magnesium dihalide, a boron compound, a halogenated hydrocarbon compound and a titanium tetrahalide compound and an organoaluminum compound has sustained catalytic activity. It was suggested that it is excellent in sex. However, this proposal still leaves room for improvement in catalytic activity.

Therefore, the present inventors have conducted intensive studies to develop a highly active polymerization catalyst that takes advantage of the merits of the solution polymerization method and the high temperature and high pressure polymerization method, and as a result, found the present invention.

[0014]

SUMMARY OF THE INVENTION The object of the present invention is to carry out α-olefin reaction in a temperature range higher than the melting point of polyethylene, that is, in solution polymerization or high temperature / high pressure polymerization, with such a high activity that a catalyst removal step is not required. It has excellent properties and can control the distribution of branching degree of the obtained polyethylene.
It is to provide a catalyst system composed of two components, which is not complicated in practical use.

[0015]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a catalyst comprising a transition metal compound and an organometallic compound,
In polymerizing ethylene at a reaction temperature equal to or higher than the melting point of the polymer, or in copolymerizing ethylene with at least one α-olefin, as component (A), (I) oxygen-containing organomagnesium and / or magnesium halide (II) ) A method for producing polyethylene, which comprises using a solid catalyst component obtained by bringing titanium halide and (III) a carbon halide compound into contact with each other, and a catalyst system comprising an organoaluminum compound as component (B).

[0016]

The following compounds can be used as the oxygen-containing organomagnesium and / or magnesium halide of the above-mentioned (I) which is the reactant used in the present invention.

First, as the compounds belonging to the oxygen-containing organomagnesium, magnesium alkoxides such as methylate, ethylate, isopropylate, decalate, and cyclohexanolate, magnesium alkylalkoxides such as ethyl ethylate, magnesium hydroalkoxides such as hydroxy. Methylate, magnesium phenoxides such as phenates,
Naphthenates, phenanthrenates and cresolates, magnesium carboxylates such as acetates, stearates, benzoates, phenylacetates, adipates, sebacates, phthalates, acrylates and oleates, magnesium chelates, i.e. magnesium containing at least one magnesium-oxygen- Oxygen-containing organic compounds having an organic group bond in this order and further having at least one ligand bond to form a magnesium-containing heterocycle, such as enolates, especially acetylacetonate. Of course, this series of oxygen-containing organic compounds also includes the following compounds.

That is, a compound containing several different organic groups, such as magnesium methoxyethylate,
Complex alkoxides and phenoxides of magnesium with other metals, such as Mg [Al (OC ₂ H ₅ ) ₄ ] ₂
And Mg ₃ [Al (OC ₂ H ₅ ) ₆ ] ₂ are also included.

Next, as halogen-containing magnesium compounds, anhydrous or hydrated magnesium dihydrides, MgCl ₂ , MgCl ₂ .6H ₂ O, MgCl ₂
4H ₂ O and MgCl ₂ .2H ₂ O, compounds containing an inorganic group, such as a hydroxy group, which is bound to magnesium via oxygen in addition to the magnesium-halogen bond, such as Mg (OH) Cl and Mg (OH ) Br,
Hydrolysis products of magnesium halides (preferably chlorides) which retain a magnesium-halogen bond, a mixed composition containing a halogen-containing compound and an oxygen-containing compound of magnesium [representative of these compositions Examples are basic magnesium halides (preferably chlorides), eg MgCl ₂ .MgO.H.
₂ O, MgCl ₂ · 3MgO · 7H ₂ O and MgBr
₂ · 3MgO · 6H ₂ O, etc.] and the like.

These oxygen-containing organomagnesium or halogen-containing magnesium may be used alone or as a mixture of two or more kinds.

The titanium halide of the above (II) is Ti
Titanium trihalide or titanium tetrahalide represented by X _n (n is 3 or 4) can be used. Specifically, titanium trifluoride, titanium trichloride,
Examples thereof include titanium tribromide, titanium triiodide, titanium tetrachloride and titanium tetrabromide. Of these, titanium trichloride and titanium tetrachloride are preferably used. The titanium halides can be used alone or as a mixture of two or more kinds.

The halogenated carbon compound (III) is not particularly limited, but generally, a halogen derivative of a hydrocarbon having 1 to 20 carbon atoms is preferably used. Specific examples of such compounds include propyl chloride, -n-butyl chloride, -sec-butyl chloride, and chloride-
tert-butyl, -n-octyl chloride, -n-butyl bromide, chlorobenzene, benzyl chloride, methylene dichloride, 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobutane, trichloroethane, Examples thereof include tetrachloroethane, tetrachloroethylene, chloroform and the like.

Further, halogenated carbon compounds such as hexachloroethane, hexachlorocyclopentadiene, carbon tetrachloride and the like are also preferably used.

Reactants (I) to (III) in the present invention
The contact can be carried out by a conventional method used in the art. That is, for example, a method by co-grinding mainly containing solid components or a method by liquid phase reaction mainly containing liquid components can be used. The combined use of a plurality of these methods is also included in the present invention.

The contact of the three components of the reaction agents (I) to (III) is achieved by bringing the reaction agent (III) and the reaction agent (I) into contact with each other in the presence of the reaction agent (II). It is important for expression. For that purpose, for example, a method in which the three components are coexisted in contact with each other at the same time, or the reaction agent (I) and the reaction agent (II) are contacted and then the reaction agent (II) and the reaction agent (I
Examples thereof include a method of bringing the mixture of II) into contact. Among them, contacting the reactants (II) and (III) in two or more steps further improves the catalytic activity, and thus it is preferable to contact them in two or more steps.

When the contact is carried out by a co-grinding treatment, it is usually carried out in an inert gas atmosphere using a ball mill, a vibration mill, an impact mill or the like. The optimum conditions for the co-pulverization treatment vary depending on the type and filling rate of the balls, the rotation speed, the pulverization temperature, the pulverization time, etc., but such conditions are easily determined by experiments by those skilled in the art.

When the contact is carried out in a liquid phase reaction, it should be carried out in the presence of an inert organic solvent when these reactants themselves are not liquid under the operating conditions or when the amount of the liquid reactant is insufficient. You can As the inert organic solvent, all those commonly used in the art can be used,
Aliphatic, alicyclic, or aromatic hydrocarbons or halogen derivatives thereof, or a mixture thereof, such as hexane, heptane, cyclohexane, toluene,
Xylene and the like are preferably used.

The amount of each of the reactants constituting the solid catalyst component (A) is arbitrary as long as the effects of the present invention can be recognized, but the following ranges are generally preferred. The amount of the titanium halide used as the reaction agent (II) is in the range of 0.01 to 100 moles, preferably 0.02 to 10 moles, relative to 1 mole of the magnesium compound of the reaction agent (I). When used for pulverization, it is preferably in the range of 0.02 to 0.5 mol. The amount of the halogenated carbon compound used as the reactant (III) is in the range of 0.001 to 20 mol, and more preferably 0.05 to 5 mol in the co-milling treatment with respect to 1 mol of the magnesium compound of the reactant (I). When the contact is carried out by a liquid phase reaction, the reactant (III) can be used in a large excess as a substitute for the solvent.

The solid catalyst component (A) thus obtained
Are particles that are insoluble in the solvent used as a diluent, and can be obtained by removing the remaining unreacted substances and by-products by filtration or decantation and then washing with the insoluble solvent several times.

This solid catalyst component (A) contains Ti and carbon components, as will be described later in Examples, and it is considered that the effects of the present invention are exerted by the action of these components.

Catalyst component (B) used in the present invention
Has the general formula AlR ¹ _j (OR ² ) _k X _3-k (wherein R ¹ and R ² represent an alkyl group having 1 to 20 carbon atoms, X represents a halogen atom, j, k is 0
<J ≦ 3, preferably 0 <j <3, 0 ≦ k ≦ 2, 0 <j
+ K ≦ 3), or at least one organoaluminum compound selected from the group consisting of aluminoxanes.

The above general formula AlR ¹ _j (OR ² ) _k X
Specific examples of the organoaluminum compound represented by _3-k include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, and diethylaluminum monochrome. Alkyl aluminum halides such as chloride, diisopropyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl aluminum monobromide, diisopropyl aluminum monobromide, dimethyl aluminum ethoxide, diethyl aluminum ethoxide, diethyl aluminum propoxide , Jiechi Aluminum butoxide, diethyl aluminum phenoxide, alkyl aluminum alkoxides such as ethyl aluminum diethoxide and the like.

As the aluminoxane, it is also possible to use an aluminoxane compound in which two or more aluminum atoms are bound via an oxygen atom or a nitrogen atom, for example, a multimer such as tetramethylaluminoxane or polymethylaluminoxane.

These organoaluminum compounds are used alone or as a mixture of two or more kinds. Of course, it can be used alone, but when it is preferably used as a mixture of two or more kinds, it is more effective in improving the polymerization activity and the copolymerizability.

The amount of the organoaluminum compound used as the catalyst component (B) is 1 to 1000 mol, preferably 1 to 10 mol, per 1 gram atom of titanium contained in the catalyst component (A).
The amount is 0 mol, particularly preferably 1 to 10 mol.

The polymerization according to the invention is a homopolymerization of ethylene or a copolymerization of ethylene with at least one α-olefin. The α-olefin used for copolymerization with ethylene is preferably one having 3 to 20 carbon atoms, and specific examples include propylene, 1-butene, 1-hexene,
4-Methyl-1-pentene, 1-octene, 1-decene and the like and mixtures thereof are used.

Polymerization of ethylene is carried out above the melting point of the polymer produced. In order to exert high catalytic activity, which is a feature of the present invention, and to prevent increase in viscosity of the polymer and increase productivity, polymerization is performed at 130 to 300 ° C, preferably 150 ° C.
It is performed in a temperature range of 280 ° C.

An inert solvent or the α-olefin itself is used as the polymerization medium. In solution polymerization using an inert solvent, hexane, heptane, as a polymerization solvent,
Aliphatic hydrocarbons such as octane, nonane, decane, undecane and dodecane and mixtures thereof, aromatic hydrocarbons such as benzene and toluene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are used. Polymerization pressure is 1 to 200 kg / cm ² G, preferably 10 to 50 k
g / cm ² G, and the residence time is in the range of 10 minutes to 6 hours, preferably 20 minutes to 3 hours.

Further, in the high temperature and high pressure polymerization in which α-olefin itself is used as a polymerization medium, a high pressure radical polymerization apparatus of ethylene or the like can be generally used, and the polymerization pressure is 20
0 to 2500 kg / cm ² G, preferably 400 to 15
00 kg / cm ² G, residence time 5 to 600 seconds, preferably 10 to 150 seconds.

In the present invention, the molecular weight of the polymer can be controlled by adjusting the reaction temperature, but can be easily controlled by allowing hydrogen to be present in the polymerization zone. The amount of hydrogen varies depending on the polymerization conditions, the molecular weight of the desired ethylene polymer, and the like, so it is necessary to adjust it appropriately.

[0041]

EXAMPLES The present invention will be shown below by examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

In the examples, MI represents the melt index, which is measured according to JIS K-6760 under the conditions of 190 ° C. and a load of 2.16 kg. Density is J
It measured according to ISK-6760.

Polymerization activity is determined by the amount of polymer produced (kg) per 1 g of the solid catalyst component (A) and the solid catalyst component (A).
The polymer production amount (kg) per 1 g of titanium in the medium is shown.

The number of short chain branches was quantified by a Fourier transform infrared spectrophotometer (FT-IR) from a peak derived from a methyl group appearing near 1378 cm -1. If the amount of α-olefin used during polymerization is constant, it can be judged that the greater the number of branches, the better the copolymerizability of α-olefin.

The melting point of the polymer was determined by differential scanning calorimetry. If the molecular weight and the number of branches are the same, the polymer having a lower melting point has lower crystallinity than the polymer having a higher melting point, and it can be judged that the branching degree distribution is controlled narrowly.

Example 1 [Preparation of Solid Catalyst Component (A)] Anhydrous magnesium chloride (commercially available anhydrous magnesium chloride was preliminarily heated to 400 ° C.) in a stainless steel pot having an internal volume of 420 ml containing 1.2 kg of stainless steel balls having a diameter of 4 mmφ. 2 hours in a vacuum dry as Te) 15.0 g, and quaternary titanium trichloride titanium tetrachloride was obtained by reduction with metallic aluminum (TiCl ₃ · 1
/ A 3AlCl ₃₎ 4.0g and 1,2-dichloroethane 2.0g sealed under a nitrogen atmosphere, and pulverized for 12 hours co-vibration mill. The solid catalyst component (A) obtained after grinding is
After a small amount of suppression and compositional analysis, Ti 4.6 was obtained.
wt%, carbon 0.7 wt% and titanium trichloride and 1,
A solid catalyst component (A) carrying 2-dichloroethane was obtained. Next, 0.5 g of the solid catalyst component (A) is added to the carbon number 1
A catalyst slurry was prepared by dispersing it in 200 ml of a solvent (IP-1620 manufactured by Idemitsu Petrochemical Co., Ltd.) containing 0 to 11 isoparaffin as a main component.

[Copolymerization of ethylene and α-olefin] An autoclave with an internal volume of 1 liter and made of stainless steel equipped with an induction stirrer was replaced with nitrogen, and 600 ml of IP-1620 and 20 ml of 1-butene were added and the temperature was raised to 200 ° C with stirring. did. 2.6 kg in the system due to the vapor pressure of the solvent and 1-butene
/ Cm ² G, but the total pressure of ethylene is 22.6 kg / c
imposition until m ² G, previously prepared catalyst slurry poured polymerizing triethylaluminum (0.00867mmol) (solid catalyst 3.02Mg, a titanium atom equivalent 0.00289Mmol) and as the catalyst component (B) Started. When ethylene was continuously introduced and polymerization was carried out for 20 minutes while keeping the total pressure constant, 38.7 g of a polymer was obtained.

Polymerization activity per solid catalyst component (A) is 1
It was 2.8 kg / g. The activity per transition metal component was equal to 279.6 kg / g. MFR is 2.4g / 1
At 0 minutes, the density was 0.928 g / cm ³ . Also,
The number of ethyl branches was 16 per 1000 C, and the melting points were 2 at 109.6 ° C and 123.1 ° C.

Examples 2 to 5 Preparation was conducted under the same conditions as in Example 1 except that the solid catalyst component (A) and the catalyst component (B) were used in the ratios shown in Table 1, and ethylene and α-olefin were mixed. Copolymerization was carried out. The results are also shown in Table 1.

Comparative Examples 1 and 2 In Comparative Example 1, 1,2-dichloroethane used in Example 1 was not added, and in Comparative Example 2, silicon tetrachloride was used instead of 1,2-dichloroethane. Was prepared under the same conditions as in Example 1, and the copolymerization of ethylene and α-olefin was carried out. The results, as shown in Table 1, were that the polymerization activity was low, the number of ethyl branches was small, and the melting point was high as compared with the examples.

[0051]

[Table 1] Example 6 [Preparation of solid catalyst component (A)] Into a stainless steel pot having an internal volume of 420 ml containing 1.2 kg of stainless steel balls having a diameter of 4 mmφ, 10.3 g of anhydrous magnesium chloride same as in Example 1 and titanium tetrachloride were added. titanium trichloride obtained by reduction with metallic aluminum (TiCl ₃ · 1 / 3A
8.6 g of 1Cl ₃ ) was sealed in under a nitrogen atmosphere and co-milled for 12 hours with a vibration mill. 5.0 g of the solid component obtained after crushing was taken out, and 57 ml of titanium tetrachloride, 1.2-
90 ° C in a heptane solution containing 57 ml of dichloroethane
And reacted for 2 hours. After the reaction, hexane was added to the product, and the solid titanium component (A) was obtained by performing sufficient washing operation until no liberated titanium compound was detected. 0.5 g of the obtained solid catalyst component (A) was added to 200 ml of IP-162.
0 to disperse the catalyst slurry. The polymerization was carried out by copolymerizing ethylene and α-olefin under the same conditions as in Example 1. The results are shown in Table 2.

Example 7 Prepared under the same conditions as in Example 1, except that 4.0 g of titanium tetrachloride was used in place of the titanium trichloride used in the preparation of the solid catalyst component (A) of Example 1, And ethylene and α
-Copolymerization of olefins was carried out. The results are shown in Table 2.

Example 8 [Preparation of solid catalyst component (A)] In a stainless steel pot having an internal volume of 420 ml containing 1.2 kg of stainless steel balls having a diameter of 4 mmφ, 10.3 g of anhydrous magnesium chloride same as in Example 1 and four 4.0 g of titanium chloride, and 1,
2.1 g of 2-dichloroethane was enclosed under a nitrogen atmosphere,
Co-milled for 12 hours with a vibrating mill. 5.0 g of the solid component obtained after crushing was taken out, and 51 ml of titanium tetrachloride,
Reaction was carried out at 90 ° C. for 2 hours in a heptane solution containing 51 ml of 1.2-dichloroethane. After the reaction, hexane was added to the product, and the solid titanium component (A) was obtained by performing sufficient washing operation until no liberated titanium compound was detected.
0.5 g of the obtained solid catalyst component (A) was added to 200 ml of I.
A catalyst slurry was prepared by dispersing in P-1620. The polymerization was carried out by copolymerizing ethylene and α-olefin under the same conditions as in Example 1. The results are shown in Table 2.

Example 9 Magnesium ethoxide 1 was used instead of anhydrous magnesium chloride used in the preparation of the solid catalyst component (A) of Example 1.
5.0 g was prepared under the same conditions as in Example 1 except that 2.0 g of hexachloroethane was used instead of 1,2-dichloroethane, and copolymerization of ethylene and α-olefin was carried out. The results are shown in Table 2.

Example 10 [Preparation of solid catalyst component (A)] Stirrer, reflux condenser,
Into a 1-liter flask equipped with a dropping tube and a thermometer, 15.0 g of magnesium ethoxide was placed, and titanium tetrachloride 2
After 60 ml and 1,2-dichloroethane (260 ml) were added, the temperature was raised to 45 ° C. and the mixture was stirred for 2 hours under a nitrogen blanket. Subsequently, the temperature was raised to 70 ° C. and the reaction was performed for 2 hours to obtain a solid catalyst component (A). The solid catalyst component (A) was thoroughly washed with hexane until titanium was not detected in the liquid, and then dried at 40 ° C. under a nitrogen stream to take out the solid catalyst component (A). 0.5 g of the obtained solid catalyst component (A) was dispersed in 200 ml of IP-1620 to prepare a catalyst slurry. The polymerization was carried out by copolymerizing ethylene and α-olefin under the same conditions as in Example 1. The results are shown in Table 2.

[0056]

[Table 2] Examples 11-15 1,2 used in the preparation of the solid catalyst component (A) of Example 1
-Preparation was carried out under the same conditions as in Example 1 except that the compounds shown in Table 3 were used instead of dichloroethane, and copolymerization of ethylene and α-olefin was carried out. The results are shown in Table 3.

Example 16 An autoclave with an internal volume of 2 liters made of stainless steel and equipped with an induction stirrer was replaced with nitrogen to obtain 1200 ml of IP-1620.
And 1-hexene (40 ml) are added, and the mixture is stirred while stirring.
The temperature was raised to 0 ° C. The system becomes about 2.61 kg / cm ² G by the solvent and the vapor pressure of 1-hexene, but the total pressure of ethylene is 6
The solid catalyst component (A) slurry used in Example 1 [solid catalyst component (A) titanium atom equivalent to 0.00202 mmol] and triethylaluminum (0.00605) as the catalyst component (B) were filled up to 0 kg / cm ² G.
(mmol) was added to initiate polymerization. When ethylene was continuously introduced and polymerization was carried out for 20 minutes while keeping the total pressure constant, 77.8 g of a polymer was obtained. The polymerization activity per solid catalyst component (A) was 36.9 kg / g. The activity per transition metal component was 804.1 kg / g. MFR is 1.9 g / 10 minutes and density is 0.9
It was 24 g / cm ³ . The number of ethyl branches is 100.
16 per 0C, melting points 110.2 ° C and 12
Two points of 3.1 ° C were observed.

Example 17 In a vertical cylindrical reactor equipped with a stirrer, triethylaluminum was used as the solid catalyst component (A) and the catalyst component (B) obtained in Example 1, and ethylene and 1-hexene were continuously added. The temperature in the polymerization vessel is 180 ° C and the pressure is 800 kg /
Polymerization was carried out while maintaining cm ² G. The average residence time in the polymerization vessel was 50 seconds, the molar ratio of ethylene and 1-hexene was 65/35, and the catalyst supply was 0.38 solid catalyst component (A).
7 g and triethylaluminum (1.11 mmol) as a catalyst component (B) were supplied at a rate of 1 hour, and polymerization was performed for 8 hours. As a result, 2 per hour
3.8 kg of ethylene copolymer was obtained. The polymerization activity per solid catalyst component (A) was 61.5 kg / g, and the activity per transition metal component was 1340 kg / g. MI is 2.4 g / 10 minutes and the density is 0.92.
It was 5 g / cm ³ . The number of ethyl branches is 1000.
16 per C, melting points 109.4 ° C. and 122.
Two points of 9 ° C were observed.

[0059]

[Table 3]

[0060]

The effect of the present invention is that, firstly, a polymer having extremely high polymerization activity per transition metal and per solid catalyst, which does not require a deashing step for the purpose of catalyst removal, can be obtained. Since it is highly active, there is no need to worry about coloring or odor of the product, and there is no need to purify the polymer, which is extremely economical.

The second effect of the present invention is that since the copolymerizability with α-olefin is good, the polymerization conversion rate of α-olefin is higher than that of other catalyst systems and a copolymer having a desired density is obtained. That is, a small amount of α-olefin used for obtaining is required.

The third effect of the present invention resides in that the degree of branching distribution of the obtained copolymer can be controlled. Therefore, depending on the use, the melting point, crystallinity, which are the basic properties of the copolymer,
It is possible to control the crystallization rate, the crystal structure, and the like.

The fourth effect of the present invention is that since the catalyst component is a two-component system, there is no need to improve the conventional polymerization equipment using a Ziegler-type catalyst, and the control during polymerization is a conventional two-component control. It can be used in.

[Brief description of drawings]

FIG. 1 is a catalyst preparation diagram (flow chart) in the present invention.
Indicates.

Claims (1)

[Claims] 1. When polymerizing ethylene or copolymerizing ethylene and at least one α-olefin in the presence of a catalyst composed of a transition metal compound and an organometallic compound at a reaction temperature equal to or higher than the melting point of the polymer, (A) ) Component, (I) oxygen-containing organomagnesium and / or magnesium halide (II) titanium halide and (III) solid catalyst component obtained by contacting carbon halide compound, and (B) component, organoaluminum A method for producing polyethylene, which comprises using a catalyst system comprising a compound.