JPS6149326B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for polymerizing ethylene, or a method for copolymerizing ethylene and olefins and/or polyenes that can be copolymerized therewith. More specifically, the present invention relates to a method for polymerizing or copolymerizing ethylene that uses a novel catalyst with extremely high activity to obtain a highly active polymer with a wide molecular weight distribution, and in particular relates to film molding, blow molding, This invention relates to a method for producing an ethylene polymer or copolymer that is highly suitable for extrusion molding. In the present invention, what is referred to below as ethylene polymerization may include not only ethylene homopolymerization but also copolymerization of ethylene with α-olefins and/or polyenes that can be copolymerized with ethylene. Furthermore, copolymers may also be included in the term ethylene polymer. In recent years, methods have been studied and devised to greatly improve the catalyst utilization efficiency of so-called Ziegler-type olefin polymerization catalysts, which are composed of transition metal compounds and organometallic compounds. In particular, for the purpose of increasing the utilization efficiency of transition metal compounds, a transition metal supported Ziegler catalyst component was prepared by reacting a transition metal compound such as titanium or vanadium with various carriers, and this was combined with an organometallic compound to produce ethylene. Many methods have been proposed for forming polymerization catalysts. A wide variety of substances are used as carriers for this purpose, but magnesium compounds such as magnesium halides, magnesium alkoxides, magnesium alkoxy halides, magnesium oxides, and magnesium hydroxides are used to obtain particularly high polymerization activity. is known to be preferable. Furthermore, a solvent-soluble highly active catalyst component can be obtained by combining a titanium compound, such a magnesium compound, and a solubilizer without preparing a solid supported catalyst component. It can be used in the same way as a supported catalyst component. In ethylene polymerization using these highly active catalysts, the activity per transition metal is extremely high, making it possible to remove the catalyst in the polymerization process and omit post-treatment steps, thereby significantly simplifying the ethylene polymer production process. However, when ethylene polymers are produced using Ziegler-type catalysts activated by such magnesium compounds, the molecular weight distribution is generally narrow, and while this is very effective as a grade for injection molding and rotational molding, it is difficult to produce film. Polymers that are difficult to use for molding, blow molding, etc. are often formed. For example, in the field of film molding and blow molding, production capacity is inevitably reduced due to increased resin pressure during molding, and on the other hand, the shape of the resulting molded product becomes unstable, the film strength decreases,
This has the disadvantage of causing adverse effects such as rough skin and deterioration of transparency properties, resulting in poor commercial value. This roughening of the surface of the molded product or the increase in resin pressure during molding is closely related to the molecular weight distribution of the ethylene polymer, and by widening the molecular weight distribution, the above problems can be solved. For this reason, even when using such a magnesium-based supported catalyst component, various proposals have been made to widen the molecular weight distribution by changing the polymerization temperature, cocatalyst selection, catalyst modification, etc. In the proposed method, when trying to widen the molecular weight distribution to a desired degree, the contact activity generally decreases, and even if a magnesium-based supported catalyst component is used to increase the activity per unit weight, the catalyst removal step is omitted. This tends to cause problems in that the manufacturing advantages are not fully utilized. The inventors of the present invention conducted extensive studies on methods for solving the above-mentioned problems, and as a result, established a method for easily controlling molecular weight distribution over a wide range of molecular weight distribution, resulting in the present invention. According to the research conducted by the present inventors, it has a sufficiently high activity that the catalyst removal step can be omitted, has a wide molecular weight distribution, and can easily control the molecular weight distribution to a desired value.
It has been discovered that it is possible to provide a process for polymerizing ethylene that simultaneously provides an excellent ethylene polymer suitable for extrusion molding and blow molding. That is, according to the research of the present inventors, (A) contains at least titanium, magnesium and halogen obtained by reacting a magnesium compound and a titanium compound, and has a titanium content of about 0.2
a highly active titanium catalyst component which is a solid catalyst component having a halogen/titanium (molar ratio) of about 4 to about 300 and a specific surface area of about 10 m ² /g or more; (B) an organoaluminum compound; Ethylene or It has been found that by polymerizing or copolymerizing ethylene with about 10 mol% or less of other α-olefins and/or polyenes, it is possible to provide a method for polymerizing ethylene that combines the above-mentioned improvements. According to the research of the present inventors, the use of the above (B) organoaluminum compound and the above (C) aluminum trihalide in combination with the highly active titanium catalyst component (A) enables the Ziegler type catalyst to be activated. It has been discovered that compared to the case where the conventionally known organoaluminum compound is used alone or in combination as a cocatalyst for ethylene polymerization, the advantage of high activity of the catalyst is fully exhibited and the molecular weight distribution is significantly broadened. Moreover, according to the method of the present invention, an ethylene polymer having a desired molecular weight distribution can be easily obtained by changing various combinations and/or mixing ratios of the organoaluminum compound (B) and the aluminum trihalide (C). An unexpected and surprising fact has been discovered that it can be obtained with high catalytic activity. Therefore, an object of the present invention is to provide a method for polymerizing ethylene that has high catalytic activity and can provide a wide molecular weight distribution with easy control means and with good quality reproducibility. The above objects as well as many other objects and advantages of the present invention will become more apparent from the following description. Highly active titanium catalyst component (A) used in the present invention
is a titanium catalyst component activated by a magnesium compound, and contains at least magnesium, titanium, and halogen as essential components. Usually, it is a catalyst component capable of producing about 50 g or more of ethylene polymer per 1 mg of titanium. Generally, the catalyst component (A) is in a solid state, but it may be one in which a magnesium compound, a solubilizer, and a titanium compound are dissolved in a hydrocarbon or the like. Titanium in the catalyst component (A) is usually tetravalent and/or trivalent. The solid catalyst component (A) has a titanium content of about 0.2 to about 18% by weight, more preferably about 0.3 to about 15% by weight, and a halogen/titanium (molar ratio) of about 4 to about 300%. , more preferably from about 5 to about 200. Further, its specific surface area is about 10 m ² /g or more, more preferably about 20 m 2 /g or more.
from about 1000 m ² /g, more preferably from about 40 to about 900 m ² /g. Such a solid highly active titanium catalyst component (A) is widely known, and basically, a reactant with a large specific surface area is obtained by reacting a magnesium compound and a titanium compound, or a reactant with a large specific surface area is obtained. A method of reacting a titanium compound with a magnesium compound is often used. For example, co-pulverization of a magnesium compound and a titanium compound, thermal reaction of a magnesium compound with a sufficiently large specific surface area and a titanium compound, thermal reaction of an oxygen-containing magnesium compound and a titanium compound, and a method of co-pulverizing a magnesium compound treated with an electron donor. Typical examples include a method in which the material is treated in advance with an organic aluminum compound or a halogen-containing silicon compound, or is reacted with a titanium compound without treatment. There are various magnesium compounds used for producing the solid highly active titanium catalyst component (A). For example, magnesium chloride, magnesium bromide, magnesium iodide, magnesium fluoride,
Examples include magnesium hydroxide, magnesium oxide, magnesium hydroxyhalide, alkoxymagnesium, alkoxymagnesium halide, allyloxymagnesium, allyloxymagnesium halide, alkylmagnesium halide, and mixtures thereof. These may be made by any manufacturing method. The magnesium compound may also contain other metals, electron donors, and the like. The titanium compound used for producing the solid highly active titanium catalyst component (A) is Ti(OR) _4-n X _n
(R is a hydrocarbon group, X is a halogen, 0≦m≦4)
An example is a tetravalent titanium compound represented by: Examples of such titanium compounds are TiCl ₄ ,
_TiBr4 , Ti _{( OC2H5} ) _Cl3 , Ti _{( OC2H5} ) _{2Cl2 ,} Ti
Examples include (OC ₆ H ₅ ) ₃ Cl and Ti(OC ₂ H ₅ ) ₄ . Further examples include various titanium trihalides, such as titanium trichloride, obtained by reducing titanium tetrahalide with a reducing agent such as aluminum, titanium, hydrogen, or an organoaluminium compound. These titanium compounds can be used in combination of two or more types. Typical methods for obtaining such a highly active titanium catalyst component (A) include, for example, Japanese Patent Publication No. 46-34092 and Japanese Patent Publication No. 46-34092.
-34094, Special Publication Showa 46-34098, Special Publication Showa 47-41676,
Tokuko Sho 47-46269, Tokuko Sho 50-32270, Tokuko Sho 53-
1796, etc., and can be used in the present invention. As the organoaluminum compound (B) used in the present invention, compounds having at least one Al-carbon bond in the molecule can be used, for example, (i) general formula R
¹ _n ^Al ( _OR ^{2 )} nH _p Halogen, m is 0<m≦3, n is 0≦n
<3, p is a number of 0≦p<3, q is a number of 0≦q<3, and m+n+p+q=3), (ii) general formula
Examples include complex alkylated products of Group 1 metals and aluminum represented by M ¹ AlR ¹ ₄ (where M ¹ is Li, Na, or K, and R ¹ is the same as above). Examples of the organoaluminum compounds that belong to (i) above include the following. General formula R ¹ mAl
(OR ² ) _3-n (where R ¹ and R ² are the same as above. m
is preferably a number of 1.5≦m≦3), the general formula
R ¹ mAlX _3-n (where R ¹ is the same as above, X is halogen, m is preferably 0<m<3), general formula R ¹ mAlH _3-n (where R ¹ is the same as above) m is preferably 2≦m<3), general formula R ¹ mAl
(OR ² )nXq (where R ¹ and R ² are the same as above.
X is halogen, 0<m≦3, 0≦n<3, 0≦q
<3, and m+n+q=3). Among the aluminum compounds belonging to (i), more specifically, trialkyl aluminum such as triethyl aluminum and tributyl aluminum,
In addition to trialkenylaluminums such as triisoprenylaluminum, dialkylaluminum alkoxides such as diethylaluminum ethoxide, dibutylaluminum butoxide, alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide, butylaluminum sesquibutoxide, R ¹ _2.5 Al
a partially alkoxylated alkyl aluminum having _an average composition expressed as ( ^OR2 ) _0.5 ,
Dialkyl aluminum halogenides such as diethylaluminium chloride, dibutyl aluminum chloride, diethylaluminum bromide, alkyl aluminum sesquihalogenides such as ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide, ethyl aluminum dichloride, propyl aluminum dichloride, Partially halogenated alkylaluminiums such as alkylaluminum dihalides such as butylaluminum dibromide, dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride, alkyls such as ethylaluminum dihydride, propylaluminum dihydride Partially hydrogenated alkyl aluminums such as aluminum dihydride, partially alkoxylated and halogenated alkyl aluminums such as ethylaluminum ethoxy chloride, butylaluminum butoxy chloride, etheraluminum ethoxy bromide. Further, as a compound similar to (i), it may be an organoaluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl
(C ₂ H ₅ ) ₂ , (C ₄ H ₉ ) ₂ AlOAl(C ₄ H ₉ ) ₂ ,
Examples include (C ₂ H ₅ ) ₂ AlNAl(C ₂ H ₅ ) ₂ and the like. Examples of compounds belonging to (ii) above include LiAl(C ₂ H ₅ ) ₄ and LiAl(C ₇ H ₁₅ ) ₄ . Among these, it is particularly preferable to use trialkyl aluminum and dialkyl aluminum halide. Examples of the aluminum trihalide (C) used in the present invention include aluminum chloride, aluminum bromide, aluminum iodide, and aluminum fluoride, with aluminum chloride being particularly preferred. These may be used in the form of complex compounds with electron donors. (B) organoaluminum compound and (C) in the present invention
When used in combination with aluminum trihalide, (B) the organoaluminum compound component and (C) the aluminum trihalide component are each separately fed into a polymerization vessel and brought into contact with (A) the highly active titanium catalyst component. will be adopted. In liquid phase polymerization, the amount of the catalyst (A) component used in ethylene polymerization is generally about 0.0001 mmol to about 1 mmol, preferably about 0.0005 to about 1 mmol, in terms of titanium atoms per 1 polymerization solvent.
0.1 mmol, and the total amount of the organoaluminum compound and aluminum trihalide is about 0.01 to about 0.1 mmol in terms of aluminum per 1 polymerization solvent.
It is preferable to use it in a proportion of 100 mmol, preferably 0.05 to 20 mmol. At this time, Al/Ti (molar ratio)
is preferably adjusted to about 1 or more, more preferably about 5 or more, particularly preferably about 10 or more. In addition, the ratio of the organoaluminum compound (B) and the aluminum trihalide (C) can be appropriately changed depending on the polymerization temperature and polymerization conditions, but in general, suspension polymerization using a hydrocarbon solvent or In the gas phase polymerization method, the atomic ratio of aluminum in component (B)/Al in component (C) is about 100/1 to about 1/
2, particularly preferably about 50/1 to about 2/1. Further, as a combination of components (B) and (C), a combination of trialkyl aluminum or dialkyl aluminum halide and aluminum trihalide is preferred. In addition, in the high-temperature dissolution polymerization method in which the ethylene polymer and the polymerization solvent form a homogeneous phase, the proportion of the organoaluminum compound and aluminum trihalide used in component (B) is determined in terms of aluminum atoms.
Al in the Al/(C) component is about 100/1 to about 1/3,
In particular, about 50/1 to about 1/2 is preferable. The ethylene polymerization reaction using the catalysts (A), (B) and (C) of the present invention can be carried out in the same manner as the ethylene polymerization reaction using a normal Ziegler type catalyst. That is, the reaction is carried out in a state where oxygen, water, etc. are substantially excluded. The polymerization method is a suspension polymerization method in the presence of an appropriate inert solvent such as an aliphatic hydrocarbon or alicyclic hydrocarbon such as butane, pentane, hexane, heptane, kerosene, or cyclohexane, or a high-temperature solution polymerization method. be done. Alternatively, a method using gas phase polymerization in the absence of a hydrocarbon solvent is also possible. In the present invention, homopolymerization of ethylene or
Copolymerization of ethylene with other α-olefins and/or polyenes can be carried out. Other α-olefins that can be copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1
-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, etc. Examples of the polyene include butadiene, isoprene, 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and the like. In ethylene copolymerization, especially ethylene is about 90 mol%
It is preferable to carry out the copolymerization so that the content of the other α-olefin and/or polyene is about 10 mol % or less. When carrying out the ethylene polymerization of the present invention, a polymerization temperature of, for example, about 20 to about 200°C, preferably about 40 to about 180°C, is often employed. The polymerization pressure is, for example, above atmospheric pressure, preferably about 2 to about
Generally, 100Kg/cm ² is adopted. In the present invention, the molecular weight can be adjusted by changing polymerization conditions such as polymerization temperature and catalyst molar ratio, but it is more effective to add hydrogen into the polymerization system, and in the case of the present catalyst system, The effect of molecular weight reduction by hydrogen is remarkable, and a sufficient reduction in molecular weight is observed even at low hydrogen partial pressures. Therefore, by using the method of the present invention in combination with hydrogen, (B) , (C) By varying the usage ratio of both components, it is possible to obtain the desired wide molecular weight distribution. A feature of the present invention is that molecular weight adjustment using hydrogen is highly effective not only in batch polymerization but also in continuous polymerization. Other advantages of using the catalyst system of the present invention include the following. According to the method of the present invention, polyethylene with a wide molecular weight distribution and excellent processing properties for film molding, blow molding, and extrusion molding can be obtained, and because the catalytic activity is extremely high, residual catalyst in the polyethylene produced can be obtained. The amount is extremely small, so that the catalyst removal step can be omitted. Moreover, the strength of the obtained polyethylene is very high and the moldability is very good.
Furthermore, high-quality polyethylene can be obtained with less surface roughness during molding and almost no formation of fish eyes during film molding. Hereinafter, several embodiments of carrying out the method of the present invention will be described in more detail with reference to Examples. Example 1 <Catalyst Preparation> 2 moles of commercially available anhydrous magnesium chloride were suspended in dehydrated and purified hexane 5 in a nitrogen stream, 12 moles of ethanol was added dropwise over 2 hours with stirring, and the mixture was reacted for 1 hour at room temperature. . 5.4 mol of diethylaluminum chloride was added dropwise to this at room temperature,
Stirred for 2 hours. Subsequently, 15 moles of titanium tetrachloride were added, and the system was heated to 80° C. and the reaction was carried out with stirring for 3 hours. The produced solid portion was separated by decantation and washed repeatedly with purified hexane. The composition of the obtained solid was 67 mg/g-solid as Ti atoms, 640 mg/g-solid as Cl atoms, 180 mg/g-solid as Mg atoms, and 95 mg/g- as OEt base weight.
Each solid was present. Also, the specific surface area of the solid is
It was 240m ² /g. <Polymerization> Put the dehydrated and purified solvent hexane 1 into the autoclave 2, and after purging the inside of the autoclave with nitrogen, triisobutylaluminum
1.125 mmol, aluminum chloride 0.375 mmol and the above supported catalyst in terms of titanium atoms.
0.01 mmol was added and the temperature was raised to 80°C. Next hydrogen 3.5
Kg/ ^cm2 and ethylene 4.5Kg/ ^cm2 , total pressure 8
When polymerization was carried out for ² hours while continuously adding ethylene to give a bulk density of 0.34 g/cm2, the bulk density was 0.34 g/cm2.
²⁹² g of polyethylene with a melt index (MI) of 3.3 were obtained. Catalytic activity is 29200g-polymer/
Equivalent to mmol-Ti. Further, w/n (weight average molecular weight/number average molecular weight), which is a measure of the molecular weight distribution of polyethylene, was 15.1. In addition, w/
n was calculated based on the gel permeation chromatography (GPC) pattern. This had a clearly broader molecular weight distribution than the polyethylene shown in Comparative Example 1. Examples 2 to 6 Using the catalyst prepared in Example 1, ethylene was polymerized under the same polymerization conditions as in Example 1 except that the molar ratio of aluminum alkyl and aluminum chloride was changed to obtain polyethylene. The results are shown in Table 1. Comparative Examples 1 and 2 Using the catalyst prepared in Example 1, ethylene was polymerized under the same polymerization conditions as in Example 1, except that only triethylaluminum and triisobutylaluminum were used as aluminum components, respectively. Obtained. The results are shown in Table 1.

【table】

[Table] Example 7 Using 200 continuous polymerization reactors, dehydrated purified solvent hexane was used at 80/hr, aluminum chloride was
20mmol/hr, triisobutylaluminum
60 mmol/hr, the catalyst prepared in Example 1 was continuously supplied at 0.9 mmol/hr in terms of titanium, and 25 kg/hr of ethylene and butene were simultaneously supplied in the polymerization vessel.
1.0Kg/hr, continuous supply of hydrogen at a rate of 1000/hr, polymerization temperature 80℃, total pressure 8Kg/cm ² G, residence time
When ethylene was polymerized for 1 hour, an ethylene copolymer with a bulk specific gravity of 0.38 g/ ^cm3 became 24.5
Kg/hr was obtained continuously. The obtained polyethylene has MI of 0.05, density of 0.955, w/n=
It was 13.4. This polyethylene was used to mold a 400ml cylindrical bottle using a blow molding machine.
Compared to Comparative Example 3, the moldability was very good, the appearance of the bottle was good, and no formation of fish eyes was observed, and the Izod impact strength by the press sheet was also excellent. Comparative Example 3 Using the same pressurized continuous polymerization apparatus as in Example 7, hexane 80/hr, triethylaluminum 80 mmol/hr, and the catalyst prepared in Example 1 were used in the same manner as in Example 7 at a concentration of 0.8 mmol/hr in terms of titanium. Continuously supplying 26 kg/hr of ethylene in the polymerization vessel,
When ethylene was polymerized under the conditions of continuous supply of butene at a rate of 1.5 kg/hr and hydrogen at a rate of 1200/hr, polymerization temperature of 80°C, total pressure of 8 kg/cm ² -G, and residence time of 1 hr, the bulk specific gravity was 0.39 g. / ^cm3 of ethylene copolymer is
It was obtained continuously at a rate of 26.0Kg/hr. The obtained polyethylene has an MI of 0.05, a density of 0.954, and a w/
n=6.8. When a 400 ml hollow bottle was molded using this polyethylene in the same manner as in Example 7, the moldability was poor and the bottle's appearance was slightly rough. The Izod impact strength of the press sheet was also worse than that of Example 7. Example 8 1.59mmφ in a stainless steel pot with an internal volume of 700ml
Fill 100 stainless steel balls with 20.0 g of commercially available anhydrous magnesium chloride and silicon tetrachloride.
2.0 g was sealed in a nitrogen gas atmosphere and pulverized with a vibration mill (7.8G) for 25 hours. After the pulverization was completed, the mixed and pulverized solid composition was taken out from the mill in a nitrogen box. Next, the mixed pulverized solid composition was transferred into a 300 ml flask purged with nitrogen, and 10
ml of titanium tetrachloride was added, and the reaction was carried out at 130°C for 2 hours. After the reaction was completed, titanium tetrachloride and the solid product were separated by thermal filtration and washed repeatedly with dehydrated and purified hexane. The composition of the obtained solid was 20 mg/g solid as Ti atoms, 690 mg/g solid as Cl atoms, and 240 mg/g solid as Mg atoms.
Each solid was present. Also, its specific surface area is 110
m ² /g. <Polymerization> Using the same autoclave 2 as in Example 1, add dehydrated and purified hexane 1, add 1.17 mmol of triisobutylaluminum, 0.33 mmol of aluminum chloride, and 0.01 mmol of the supported catalyst in terms of titanium atoms. The temperature was raised to ℃. Next, 4 kg/cm ² of hydrogen and 4 kg/cm ² of ethylene were charged, and polymerization was carried out for 2 hours while continuously adding ethylene to make the total pressure 8 kg/cm ^2. As a result, the bulk density was 0.29.
g/cm ³ , melt index 0.85 polyethylene
Obtained 245g. Catalytic activity is 24500g polymer/
Equivalent to mmolTi. Further, w/n, which is a measure of the molecular weight distribution of polyethylene, was 17.1. This shows that the molecular weight distribution is clearly broader than that of the polyethylene shown in Comparative Example 4. Examples 9 and 10 Polyethylene was obtained by polymerizing ethylene under the same polymerization conditions as in Example 8 except that the catalyst prepared in Example 8 was used and the molar ratio of aluminum alkyl and aluminum chloride was changed. The results are shown in Table 2. Comparative Example 4 Using the catalyst prepared in Example 8, ethylene was polymerized under the same polymerization conditions as in Example 8 except that triethylaluminum was used as the aluminum component ^. 261 g of polyethylene with an index of 3.1 was obtained. The catalytic activity corresponds to 26100 g polymer/mmolTi.
Also, w/n is a measure of the molecular weight distribution of a polymer.
= 8.0. Example 11 <Catalyst Preparation> In a nitrogen stream, 1 mol of commercially available metal magnesium was added to 500 ml of dehydrated hexane, 1 mol of tetraethoxysilane was added, and the temperature was raised to 65° C. with stirring. After raising the temperature, a small amount of methyl iodide and iodine were added dropwise, followed by 2 mols of n-butyl chloride.
After the dropwise addition over a period of time, the mixture was stirred for 3 hours at the boiling point of hexane. After the reaction was completed, it was washed repeatedly with hexane, filtered and dried. 15ml for 1g of this dry solid
The solid was added to titanium tetrachloride in a proportion of titanium tetrachloride, reacted at 130°C for 2 hours, filtered while hot, and the solid portion was repeatedly washed with hexane. Composition analysis of the solid compounds obtained revealed that each of them contained 63 titanium.
mg/g-solid, chlorine 610 mg/g-solid, magnesium 205 mg/g-solid, and OEt group 83 mg/g-solid. Further, its specific surface area was 195 m ² /g. <Polymerization> Pour 1 portion of dehydrated and purified solvent hexane into the same autoclave 2 as in Example 1, and after purging the system with ethylene gas, 1.17% of triisobutylaluminum was added.
mmool, 0.33 mmol of aluminum chloride, and 0.01 mmol of the supported catalyst in terms of titanium atoms were added, and the temperature was raised to 80°C. Next, 3.5Kg/cm ² of H ₂ and 4.5Kg/cm ² of ethylene were introduced, and polymerization was carried out for 1 hour while continuously adding ethylene so that the total pressure was 80Kg/cm ² , resulting in a bulk density of 0.35g. ³²⁹ g of polyethylene with a melt index of 4.5 was obtained. The catalytic activity corresponds to 32900 g polymer/mmolTi. Further, w/n, which is a measure of the molecular weight distribution of polyethylene, was 12.2. This shows that the molecular weight distribution is clearly broader than that of the polyethylene shown in Comparative Example 5. Comparative Example 5 When ethylene was polymerized using the catalyst prepared in Example 11 under the same polymerization conditions as in Example 11 except that triisobutylaluminum was used as the aluminum component, the bulk density was 0.36 g/cm ³ , 314 g of polyethylene with a melt index of 7.3 was obtained.
The catalytic activity corresponds to 31400 g polymer/mmolTi. Also, w/ is a measure of the molecular weight distribution of a polymer.
n=7.6.

[Table] Example 12 Solvent hexane 8/hr, triethylaluminum dehydrated and purified using 20 continuous polymerization reactors
3 mmol/hr, aluminum chloride 1 mmol/hr, converting the catalyst composition obtained in Example 1 into titanium.
0.02 mmol/hr was continuously supplied, and at the same time in the polymerization vessel, ethylene was continuously supplied at a rate of 40 mol/hr and hydrogen was 20/hr, the polymerization temperature was 140°C, and the total pressure was 30 Kg/cm ²
When ethylene was polymerized under the conditions of G and residence time of 1 hr, polyethylene with a melt index of 5.6 and w/n = 8.9, which is a measure of molecular weight distribution, was continuously obtained. This polyethylene is Comparative Example 6
The molecular weight distribution was clearly broader than that of . Examples 13 to 16 Using the same continuous polymerization apparatus as in Example 12, ethylene was polymerized under the same polymerization conditions as in Example 12, except that the ratios of various aluminum alkyls and aluminum chloride were changed. The obtained polymerization results are shown in Table 3. Comparative Example 6 Using the same continuous polymerization apparatus as in Example 12, ethylene was polymerized in exactly the same manner as in Example 12, except that triethylaluminum was used as the aluminum component. The melt index of the obtained polyethylene was 4.1, and w/n = 4.7. Comparative Example 7 In Example 16, triethylaluminum and
Instead of feeding _AlCl3 separately, pre-prepared ethyl aluminum sesquichloride was added at 8.0 mol/hr.
The same procedure as in Example 16 was carried out except that the solution was supplied with Activity is 7500g-polyethylene/mmolTi・hr, MI is
7.6, w/n was 3.1.

【table】

Claims (1)

[Scope of Claims] 1 (A) Contains at least titanium, magnesium and halogen obtained by reacting a magnesium compound and a titanium compound, and has a titanium content of about
0.2 to about 18% by weight, halogen/titanium (molar ratio) about 4 to about 300, specific surface area about 10 m ² /g
The above solid catalyst component is a highly active titanium catalyst component, (B) an organoaluminum compound, and (C) aluminum trihalide, and the above (B) component and (C) component are each separately fed into a polymerization vessel. and polymerizing or copolymerizing ethylene or ethylene with about 10 mol% or less of other α-olefins and/or polyenes in the presence of a catalyst made by contacting with the highly active titanium catalyst component (A). Characteristic ethylene polymerization or copolymerization method. 2 The organoaluminum compound ( _{B )} has ^the formula R ¹ _n Al (OR ^{2 )} _o H p X is
Indicates halogen, 0<m≦3, 0≦n<3, 0≦
The method according to claim 1, wherein the compound is a compound represented by m+n+p+q=3, where p<3 and 0≦q<3. 3. The method according to claim 1, wherein the polymerization or copolymerization is carried out by suspension polymerization or copolymerization or gas phase polymerization or copolymerization. 4. The method according to claim 3, wherein the atomic ratio of Al in component (B)/Al in component (C) is about 1/2 to about 100/1. 5. The method according to claim 1, wherein the polymerization or copolymerization is carried out by solution polymerization or copolymerization. 6. The method according to claim 5, wherein the Al in component (B)/Al in component (C) (atomic ratio) is from 1/3 to 100/1. 7. The method according to any one of claims 1 to 6, wherein the polymerization or copolymerization is carried out in the presence of hydrogen.