JPS59179507A - Preparation of ethylene copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer having wide molecular weight distribution, improved strength and moldability, by copolymerizing ethylene with an alpha-olefin in the presence of a catalyst prepared by blending a reaction product of a Mg alkoxide, halogenated hydrocarbon, and a Ti compound with an organoaluminum compound by two-stage copolymerization. CONSTITUTION:Ethylene is copolymerized with an alpha-olefin in the presence of a catalyst consisting of a catalytic component obtained by reacting a magnesium alkoxide with a halogenated hydrocarbon and titanium compound and an organoaluminum compound at the first stage to give 20-60wt% polymer having 0.001-1g/10min melt index (MI) and 0.900-0.940g/cm<3> density based on total copolymer, and ethylene is copolymerized with the alpha-olefin in the presence of the polymer in the second stage to give the desired polymer having 0.01-30g/10min MI, >=20 converted value (eta0.1/eta500)MI=1 calculated by turning a ratio eta0.1/eta500 of melt viscosity at 230 deg.C at 0.1rad/sec shear rate to melt viscosity at 230 deg.C at 500rad/sec shear rate into 1g/10minMI, and 0.910-0.940 density.

Description

[Detailed description of the invention] Technical field The present invention relates to a method for producing an ethylene copolymer.

More specifically, the present invention relates to a method for producing an ethylene copolymer having a wide molecular weight distribution and excellent moldability and mechanical properties by two-stage polymerization.

Background Art Low-density ethylene copolymers obtained by copolymerizing ethylene and α-olefins (e.g., propylene, phthene-1, hexene-1, octene-1,4-methylpentene-1, etc.) at low pressure are It has the same density as low-density polyethylene made using the conventional high-pressure method, but has excellent mechanical properties.
, is expected to expand into new fields.

However, low-pressure low-density polyethylene has poor melt rheological properties compared to high-pressure low-density polyethylene, and for example, requires a large amount of electrical energy during inflation processing and has a reduced discharge rate. Attempts have been made to deal with the problem (by modifying the creu, die, etc.), but these require a large amount of cost and it is clear that no fundamental solution has been reached. In order to improve such moldability, it is easy to think of broadening the molecular weight distribution, but in order to improve the essential rheological properties as mentioned above, it is necessary to increase the molecular weight from (ultra) high molecular weight components and low molecular weight components. However, a wide molecular weight distribution is required. Therefore,
Producing such (ultra) high molecular weight or low molecular weight low density polyethylene on an open channel scale has been considered impractical due to catalyst and process problems. In other words, in the gas phase method, since the amount of recycled gas is extremely large, it takes a lot of time to change the hydrogen partial pressure, which is a molecular weight regulator contained in this gas, and during that time, a large amount of substandard products are produced. Therefore, it is not economically realistic. Furthermore, when producing (ultra)high molecular weight polyethylene using the solution method, the viscosity of the solution increases significantly, so the polymer concentration must be controlled and diluted, which impairs productivity and is not practical. Furthermore, when producing low-density polyethylene using the slurry method, especially low-molecular-weight low-density polyethylene, a large amount of soluble polymer is produced in the dispersion medium, resulting in fouling in the reaction vessel and adhesion of polymer particles. Problem: At present, it is difficult to efficiently produce polyethylene with a sufficiently low density.

In order to obtain polyolefins with a wide molecular weight distribution, many methods have conventionally been used in which olefins are polymerized by two or more multistage reactions in the presence of a polymerization catalyst. Many of them are
A method is adopted in which a low molecular weight polyolefin is produced in the first stage and a high molecular weight polyolefin is produced in the second stage, or vice versa.

Recently, methods for producing low-density polyethylene copolymers with a wide molecular weight distribution by a two-stage reaction in the presence of a supported Ziegler catalyst have been proposed, for example, in JP-A-57-21409 and JP-A-57-12.
It is disclosed in Japanese Patent No. 6808. These methods are characterized by the combination of specific polymerization catalysts and two-stage polymerization. ) However, the catalyst used in JP-A No. 57-21409 did not have sufficient activity;
The method of No. 26808 is not sufficient in terms of molecular weight distribution.

Disclosure of the Invention Purpose of the Invention The present inventors have made extensive efforts with the aim of providing a method for efficiently producing an ethylene copolymer having a wide molecular weight distribution and excellent properties in both mechanical properties and moldability. As a result of studies, the present inventors have completed the present invention by discovering that the above object can be achieved by combining the catalyst for polyolefin production that the present inventors had previously invented and a two-stage polymerization method.

Summary of the Invention In other words, the gist of the present invention is that in the presence of a catalyst component made by contacting magnesium alkoxide, halogenated hydrocarbon hydrogen, and a titanium compound, and a catalyst made of an organoaluminum compound, Copolymerize and
Melt index 0.001-1t/10min, density 0
．． 900 to 0.94017 cm3 of polymer is produced from 2Ω to 60% by weight of the total copolymer, and in the second stage, ethylene and α-olefin are copolymerized in the presence of the polymer to obtain a melt index of 1XL01 to 3o7/ 1o minute, 23
Shear rate o1rad at 0° 7 seconds and 500rad
The value obtained by converting the ratio of melt viscosity at 7 seconds, ηo, 1/η500, into a melt index of 1y/1o (η., 1
/η5oo) Ml: -1 is 20 or more, density α910
The present invention provides a method for producing an ethylene and α-olefin copolymer of ~r3.94097 cm3. .

Raw materials for preparing catalyst components Each raw material used in preparing the catalyst component used in the present invention will be explained.

(1) Magnesium alkoxide The magnesium alkoxide used in the present invention is represented by the general formula Mg(OR) (OR'). In the formula, R and R' are alkyl, alkenyl, cycloalkyl, aryl, or aralkyl groups having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Further, R and R' may be the same or different.

Examples of these compounds include: Mg(OOHa)z, Mg(OOzHs)z,
Mg (QC!H3) (002H5).

Mg(Ol-03H?)2 + Mg(oC3”
? )2 ; Mg(OCJ 119 )2 rM
g(Oi-C!4Hg)2. Mg(OC4H3)(
O1~C4H9) IMg (QC!4H9) (0,,,
04H9) r Mg(0(6H+3)2゜Mg(O
csax7)z, Mg(OO6H++)z, M
g(OC6Hs)z.

Mg(006H4(!H3)z, Mg(OCjHz
C6Hs)z, etc. can be mentioned.

When these magnesium alkoxides are used, it is desirable to dry them, and it is particularly desirable to dry them by heating under reduced pressure. Furthermore, it is preferable to use one that has been dried and then ground.

(2) Halogenated hydrocarbon The halogenated hydrocarbon used in the present invention has 1 to 1 carbon atoms.
Mono- and polyhalogen substituted products of two saturated or unsaturated aliphatic, alicyclic and aromatic hydrocarbons. Specific examples of these compounds include aliphatic compounds such as methyl chloride, dimethyl bromide, methyl iodide, methylene chloride, methylene bromide, methylene iodide, chloroporum, bromoform, iodoform, carbon tetrachloride, carbon tetrabromide, and carbon iodide, ethyl chloride,
Ethyl bromide, ethyl iodide, 1,2-dichloroethane, 1,2-dibromoethane, 1,2-SiE
-)' Ethane, methylchloroform, methylbromoform, methyliodoform, 1,1,2-trichloroethylene, 1.1.2-)lipromoethylene, 1,1,
2.2-tetrachloroethylene, pentachloroethane,
Hexachloroethane, hexabromoethane, n-propyl chloride, 1,2-dichloropropane, hexachloropropylene, occuchloropropane, decabromobutane, chlorinated paraffin, and alicyclic compounds such as chlorocyclopropane, tetrachlorocyclopentane, Hexachloroentazinine, hexachlorocyclohexane, aromatic compounds include chlorobenzene, bromobenzene, O-dichlorobenzene, p-dichlorobenzene, hexachlorobenzene, hexabromobenzene, pencitrichloride, p-chlorobenzene. Examples include chloride.

Not only one kind but also two or more kinds of these compounds may be used.

(3) Titanium compounds Titanium compounds are divalent, trivalent, and tetravalent titanium compounds, and examples thereof include titanium tetrachloride, titanium tetrabromide, trichloroethoxytitanium, dichlorobutoxytitanium, Examples include dichlorjetoxytitanium, dichlordibutoxytitanium, dichlordiphenoxytitanium, chlortriethoxytitanium, chlortributoxytitanium, tetrabutoxytitanium, titanium trichloride, and the like.

Among these, tetravalent titanium halides such as titanium tetrachloride, trichlorethoxytitanium, dichlorodibutoxytitanium, and dichlordiphenoxytitanium are preferred, and titanium tetrachloride is particularly preferred.

Preparation method of catalyst component The catalyst component used in the present invention can be obtained by contacting a magnesium alkoxide, a halogenated hydrocarbon, and a titanium compound. A method of contacting a hydrocarbon and then contacting a titanium compound, (
2) A method of simultaneously contacting a magnesium alkoxide, a halogenated hydrocarbon, and a titanium compound can be mentioned.

The method (1) will be explained below.

The magnesium alkoxide and the halogenated hydrocarbon can be brought into contact by mechanically co-pulverizing a solid or slurry mixture of the magnesium alkoxide and the solid or liquid halogenated hydrocarbon, or by simply stirring the mixture with an orange. This can be accomplished by other methods. Among these, a contact method of mechanical co-pulverization is preferred.

The halogenated hydrocarbon may be any of the compounds mentioned above, but polyhalides of hydrocarbons having 2 or more carbon atoms are preferred.

Examples of these include 1,2-dichloroethane, 1, 1.
2-) dichloroethane, 1.1.2-trichloroethylene, 1,1,2.2-tetrachloroethane, 1,2.
Examples include 2.2-tetrachloroethane, pentachloroethane, hexachloroethane, i,2-dichloropropane, hexachloropropylene, octachloropropane, and hexachlorobenzene.

The contact ratio of magnesium alkoxide and halogenated hydrocarbon is 0.01 to 20 mol, preferably 0.1 to 2.0 mol, of halogenated hydrocarbon per mol of magnesium alkoxide.
It is 0 mole.

In the case of mechanical co-pulverization, the contact between the two may be carried out using a normal pulverizer used to obtain a pulverized product, such as a rotary ball mill, vibrating ball mill, impact mill, etc. be able to. The co-pulverization treatment can be carried out, if necessary, under reduced pressure or in an inert gas atmosphere, and in a state where moisture, oxygen, etc. are substantially absent.

In the case of mechanical co-pulverization, the contact temperature is 0 to 200°C, and the contact time is 0.5 to 100 hours. Further, in the case of a contact method of simply stirring, the contact temperature is 0 to 200°C, and the contact time is 0.5 to 100 hours.

The magnesium alkoxide may be contacted with a magnesium halide before contacting with the 710 hydrogenated hydrocarbon.

Examples of magnesium halides include magnesium cybaride, magnesium chloride, magnesium bromide,
Magnesium iodide is preferred, especially magnesium chloride.

For convenience of use, it is usually advantageous to use powdered magnesium halides with an average particle size of about 1 to 50 μm, but those with even larger particle sizes can also be used.

Further, these magnesium halides are desirably so-called anhydrous ones that do not substantially contain crystal water. Therefore, when using commercially available products, heat them at 200 to 600°C in the presence of an inert gas such as nitrogen, or at 100°C under reduced pressure before use.
Although it is preferable to heat the treatment at a temperature of ~400°C, etc., there is no particular limitation.

The contact between the magnesium alkoxide and the magnesium halide can be achieved by mixing and stirring them in the presence or absence of an inert hydrocarbon, mechanically co-pulverizing them, or the like.

Examples of inert hydrocarbons include hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, and the like.

The contact ratio between magnesium alkoxide and magnesium halide is 01 to 10 moles of magnesium halide per 1 mole of magnesium alkoxide, preferably 0.
．． It is 3 to 2.0 moles. In the case of contacting in the presence of an inert hydrocarbon, the hydrocarbon is added in an amount of 1 to 1 per 100 1 of the total amount of magnesium alkoxide and magnesium halide.
It is desirable to use 100 grams.

When mechanically co-pulverizing the magnesium alkoxide and the magnesium chloride, the contact temperature is between room temperature and 20D.
℃ for 11.1 to 100 hours, and when mixing and stirring in the presence of the hydrocarbon, it is desirable to carry out the mixing at room temperature to 200℃ for 1 to 100 hours.

Among these contact methods, a method of mechanical co-pulverization is particularly desirable. The mechanical co-pulverization method may be carried out in the same manner as the co-pulverization method in the method of contacting magnesium alkoxide and halogenated hydrocarbon.

Magnesium alkoxide, which has been previously treated with magnesium halide as described above, is brought into contact with a halogenated hydrocarbon as described above, but in this case, a halide of a hydrocarbon having one carbon number may also be used. obtain.

Alternatively, the magnesium alkoxide, the magnesium halide, and the halogenated hydrocarbon may be brought into contact at the same time.

(2) Contact with a titanium compound The contact product of the magnesium alkoxide and the halogenated hydrocarbon (hereinafter referred to as the contact product) is then brought into contact with a titanium compound to form the catalyst component of the present invention. The contact article may be cleaned with a suitable cleaning agent, such as the inert hydrocarbons mentioned above, before contacting with the titanium compound.

The contact material and the titanium compound may be brought into contact with each other for a while, but they may be mixed and stirred in the presence of a hydrocarbon and/or halogenated hydrocarbon, or mechanically co-pulverized. It is preferable to do so.

Examples of hydrocarbons include carbon atoms having 6 to 12 carbon atoms, such as hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene. Preferably, enclosing aliphatic, iQ wasofun type and aromatic hydrocarbons are used. Further, as the halogenated hydrocarbon, any compound can be used as long as it is used when brought into contact with the magnesium alkoxide.

The contact between the contact material and the titanium compound (the use of both in C) is carried out at a rate of 1 gram atom of magnesium in the contact material, 1 gram mole or more of the titanium compound α, preferably 1 to 5
Gram mole. In addition, the contact conditions are 0 to 2 when carried out in the presence of hydrocarbons and/or halogenated hydrocarbons.
0.5 to 20 hours at 00℃, preferably 60 to 150℃
It takes 1 to 5 hours.

The amount of hydrocarbons and/or halogenated hydrocarbons used.
1 per A of the liquid substance (hydrocarbon and/or liquid halogenated hydrocarbon and liquid titanium compound) in which the contact material is
It is preferable to use a value between 0 and 3002.

The solid substance obtained as described above is separated from the liquid substance, washed with an inert hydrocarbon such as hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, etc. as necessary, By drying, the catalyst component according to the present invention can be obtained.

The catalyst component prepared as described above may be subjected to ethylene copolymerization (C), but prior to use, it is brought into contact with an olefin and a specific aluminum compound (hereinafter referred to as pretreatment). You may also use the following.

Pretreatment can be carried out in the presence of an inert hydrocarbon,
It is desirable to first contact the catalyst component with the olefin and then with the organoaluminum compound. The treatment temperature is usually 0 to 80°C.

Shibolimer is generated by the pretreatment and coexists with the catalyst component by being added to the catalyst component, but it is desirable that the amount thereof is 0.05 to 107 parts per 12 parts of the catalyst component.

The pretreatment has the effect of preventing the catalyst component and the final polymer from becoming fine, making it easier to adjust the particle size, and improving the mechanical strength of the catalyst component.

Ethylene Copolymerization Catalyst The polymerization catalyst used in the present invention is a combination of a catalyst component and an organoaluminum compound.

The organoaluminum compound to be combined with the organoaluminum compound catalyst component has the general formula Rn1X3-n (wherein R is an alkyl group or an aryl group, and X is a hydrogen atom), a rogen atom, an alkoxy group, or a hydrogen atom, and n is 1 < n < , , is any number in the range of 5. ) and has 1 to 18 carbon atoms, such as trialkylaluminum, dialkylaluminum monomonolide, monoalkylaluminum dino\lide, alkylaluminum sesquinolide, dialkylaluminum monoalkoxide, and dialkylaluminum monohydride. , preferably 2 carbons
Particularly preferred are 6 to 6 alkyl aluminum compounds or mixtures or complexes thereof. Specifically, trimethylaluminum, triethylaluminum, trif 0? :”/l/l/ trialkylaluminum such as fluminate trialkylaluminum and trihexylaluminum, dialkylaluminum monohalide such as dimethylaluminum chloride, diethylaluminum chloride, diethylaluminium bromide, diethylaluminium iodide, diisobutylaluminum chloride, methyl Aluminum dichloride, ethylaluminum dichloride, ethyl 7A, monoalkylaluminum civalide such as minium cyfuromide, ethylaluminum diiodide, isobutylaluminum dichloride, alkylaluminum sesquihalide such as ethylaluminum sesquichloride, dimethylaluminum methoxide, diethyl Dialkyl aluminum monoalkoxide such as aluminum nidoxide, diethylaluminium phenoxide, dipropyl aluminum ethoxide, diimbutyl aluminum ethoxide, diisobutyl aluminum phenoxide, dimethyl aluminum hydride, diethyl aluminum hydride, dipropyl aluminum hydride, diisobutyl aluminum Dialkyl aluminum hydride such as hydride is praised.

Among these, trialkylaluminum is preferred, particularly triethylaluminum and triisobutylaluminum. These trialkylaluminums may also be combined with other organoaluminum compounds such as industrially easily available diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum ethoxide, diethylaluminum hydride, or mixtures or complexes thereof. It can be used in combination with other compounds.

Furthermore, the organoaluminum compound may be used alone or in combination with an electron-donating compound. Examples of electron-donating compounds include carboxylic acids, carboxylic esters, alcohols, ethers, ketones, amines, amides, nitriles, aldehydes, alcoholates, and those bonded to organic groups via carbon or oxygen. phosphorus,
Examples include arsenic and antimony compounds, phosphoamides, thioethers, thioesters, and carbonate esters, and among these, carboxylic acid esters, alcohols, and ethers are preferred.

Specific examples of carboxylic acid esters include butyl formate, ethyl acetate, butyl acetate, ethyl acrylate, ethyl butyrate, isobutyl isobutyrate, methyl methacrylate, diethyl maleate, diethyl tartrate, ethyl cyclohexanecarboxylate, ethyl benzoate, Ethyl p-methoxybenzoate, methyl p-methylbenzoate, ethyl p-tertiary butylbenzoate, dibutyl phthalate, diallyl phthalate, α
Examples include, but are not limited to, -ethyl naphthoate. Among these, alkyl esters of aromatic carboxylic acids, particularly alkyl esters of benzoic acid or nuclear substituted benzoic acids having 1 to 8 carbon atoms such as p-methylbenzoic acid and p-methoxybenzoic acid, are preferably used. Alcohols are represented by the general formula ROH. In the formula, R is alkyl, alkenyl, cycloalkyl, aryl, or aralkyl having 1 to 12 carbon atoms. Specific examples thereof include methanol, ethanol, propatool, impropatol, butanol, imbutanol, pentanol, hexanol, octatool, 2-ethylhexanol, cyclohexanol, benzyl alcohol, allyl alcohol, and the like. Ethers are represented by the general formula ROR'. In the formula, R and R' are alkyl, alkenyl, cycloalkyl, aryl, and aralkyl having 1 to 12 carbon atoms, and R and R' may be the same or different. Specific examples thereof include diethyl ether, diisopropyl ether, dibutyl ether, diyne butyl ether, diisoamyl ether, di-2-ethylhexyl ether, sialyl ether, ethyl allyl ether, butyl allyl ether, diphenyl ether, anisole, ethylphenyl ether, etc. .

These electron-donating compounds may be used when the organoaluminum compound is used in combination with a catalyst component, or may be used after being brought into contact with the organoaluminum compound in advance.

The amount of organoaluminum compound used relative to the catalyst component is
Per gram atom of titanium in the catalyst component, usually 1 to 20
0 gmol, especially 20 to 500 gmol is desirable. The ratio of the organoaluminum compound to the electron donating compound is such that the organoaluminum compound is carried as aluminum in an amount of 0.1 to 40, preferably 1 to 25, gram atom per mole of the electron donating compound.

Method for Producing Ethylene Copolymer Ethylene and α-olefin are copolymerized in two stages using the catalyst component thus obtained and a catalyst comprising an organoaluminum compound.

In the first stage, a high molecular weight ethylene copolymer is produced, and in the second stage, a low molecular weight ethylene copolymer is produced.

In the method of producing low-molecular-weight ethylene copolymer in the first stage, it is necessary to increase the concentration of hydrogen, which is a molecular weight regulator, so that unreacted dissolved hydrogen flows into the second stage, reducing the amount of polymer produced in the second stage. It is not possible to reduce the molecular weight and produce an ethylene copolymer with a sufficiently wide molecular weight. Therefore, a means for removing dissolved hydrogen between the first stage and the second stage is required.

In addition, when producing a high molecular weight ethylene copolymer in the first stage, there is no problem like the above, but since a large amount of hydrogen is added in the second stage to reduce the molecular weight, the catalyst activity is reduced due to hydrogen and the As the catalyst activity deteriorates over time due to the reaction in the first stage, the catalyst polymerization activity in the second stage decreases significantly, resulting in a decrease in productivity due to restrictions on the quantitative ratio of the polymers in the first stage and the second stage. If the molecular weight adjustment effect of hydrogen is small, the partial pressure of hydrogen must be increased in order to produce a polymer with a high melt index in the second stage, and the total pressure in the second stage must be high. Inconveniences arise, such as having to increase the pressure in the stages more than necessary or installing a pressure booster between the first and second stages to transfer the first stage reaction product.

Furthermore, when attempting to lower the density of the resulting copolymer, a large amount of wax-like polymer is produced in both the first and second stages.
There are problems such as fouling of the reaction vessel, and it is necessary to suppress the amount of waxy polymer produced.

For this reason, it is necessary to use a polymerization catalyst that exhibits high catalytic activity, and in particular, the catalytic activity in the second stage must be at least 150%.
．． Of・Polymer/7・Catalyst component・Time・Ethylene partial pressure (
A polymerization catalyst having a catalytic performance of Kq/cm2) or higher is required.

The catalyst used in the present invention satisfies these conditions.2. The amount of wax-like polymer produced is small, and stable, long-term continuous operation is possible.

The present invention is to produce a copolymer with a wide molecular weight distribution by greatly changing the melt index of the copolymers obtained in the first and second stages, but each melt index is the same as that obtained in the first stage. Copolymer is 0001~10f/
10 minutes, the copolymer obtained in the second stage is 50~2ooor
/10 minutes.

The melt index of the copolymer obtained in the first stage is 00
If the time is less than 710 minutes, the overall melt index decreases and moldability decreases. Moreover, if it exceeds 1r/1o, the molecular weight distribution will not be widened and the effect of improving moldability will not be sufficient.

The melt index of the copolymer obtained in the second stage is so
If it is less than 2ooor/1o, the molecular weight distribution will not be widened and the moldability improvement effect will not be sufficient.
When the amount of o is increased, the amount of low molecular weight polymer increases,
This causes fouling within the reactor, significantly deteriorating operability.

The melt index of the copolymer can be adjusted by supplying hydrogen and adjusting the supply amount.

The densities of the copolymers obtained in the first and second stages need to be 0900 to 0940 f/cfn3 in the first stage and 0.910 to 0 and 95097 cm3 in the second stage, respectively. If it is below this range, the final copolymer will become sticky, and if it is above this range, physical properties such as iMM boundary stress cracks will deteriorate. Density can be adjusted by the amount of α-olefin copolymerized with ethylene.

The quantitative ratio of the ethylene copolymer polymerized in the first stage and the second stage is
The weight ratio is 2'0:80 to 60:40.

Outside this range, it becomes difficult to sufficiently widen the molecular weight distribution.

Examples of the α-olefin used in the copolymerization include propylene, 1-butene, 4-methyl-1-pentyl, 1-hexene, and 1-octene.

The polymerization reaction can be carried out either continuously or batchwise, but a continuous method is preferred.

The polymerization reaction is preferably carried out in a liquid phase of inert hydrocarbon in both the first and second stages, and can be carried out in the presence or absence of a gas phase.

Examples of inert hydrocarbons include saturated aliphatic hydrocarbons such as normal butane, isobutane, normal pentane, impentane, hexane, heptane, and octane; saturated alicyclic hydrocarbons such as cyclobencune and cyclohexane; benzene;
Aromatic hydrocarbons such as toluene and xylene are mentioned, and mixtures thereof can also be used. Considering the solubility of the inert hydrocarbon copolymer and the difficulty of separation operation, light saturated aliphatic hydrocarbons such as rut, normal butane, and isobutane are preferable.

The polymerization temperature is usually -20°C to +150°C, preferably 5°C.
The temperature is 0 to 100°C, and the polymerization pressure is usually 1 to 60 atm.

By doing this, the melt index is 0.01 to 3.
or/1o min, shear rate 0.1 racl at 260°C
Ratio η of melt viscosities at 7 seconds and 500 rad, 7 seconds. , 1/ηsoo is the melt index 17/
Value converted to 10 minutes (ηo, 1/η500) M knee 1 (hereinafter abbreviated as [η]) 20 or more, density 0, 9
A copolymer of ethylene and α-olefin of 10 to 0.940 ff7cm3 can be produced.

Note that [η] is a value obtained using the following equation.

When the melt index is less than o, o 1y / 1o min, the effect of improving moldability is small even if the molecular weight distribution is widened, and when it exceeds 30 y / 1o min, the mechanical properties deteriorate. Moreover, if [η] is less than the above value, the moldability will not be sufficient.

Effects of the Invention The ethylene copolymer with a wide molecular weight distribution obtained by the method of the present invention has both the excellent mechanical properties of the high molecular weight component and the good fluidity during molding of the low molecular weight component, and has strong tear strength. Good moldability.

In addition, the catalyst component used in the present invention exhibits high catalytic activity and has a large molecular weight control effect with hydrogen, so that a polymer with a high melt index can be easily obtained.
Catalytic activity does not decrease even under high hydrogen partial pressure, and high catalytic activity can be maintained even in the second stage polymerization reaction.

Furthermore, there is little formation of wax-like polymers, and there is little fouling of the reactor during polymerization, allowing stable operation for long periods of time even in continuous polymerization.

EXAMPLES Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In addition, the percentages (%) shown in Examples and Comparative Examples
By weight unless otherwise specified.

Polymer melt index (M) is determined by ASTM
According to D 1238, temperature 190°C, load 2.16
Measured at 7. The normal hexane soluble content (nHxs), which indicates the proportion of solvent-soluble polymer in the polymer, is the proportion of dissolved polymer when the polymer is extracted with boiling normal hexane for 95 hours using a modified Nxhlet extractor.

The specific activity (R3P, ) of the catalyst indicates the amount of polymer produced (7) per catalyst component 17, polymerization time 1 hour, ethylene concentration 1 mole during polymerization, and ethylene partial pressure 1 atmosphere. When a pretreated catalyst component was used, the specific activity was calculated in terms of the catalyst component before pretreatment.

The bulk density (BD) of the ethylene copolymer is ASTM D 1
Measured according to 895-69 Method A. The density of the ethylene copolymer was determined by the density gradient tube method according to J.K. SK-6760.

Environmental stress fracture resistance (ESCR) is ASTM D1693-
70, the measurement was carried out at 60°C using a 10% nonionic aqueous solution. Tear strength was measured according to ASTM D1922-/+7. The sample piece used was a film with a thickness of 100 μm. The tear strength is the value corrected by the thickness (f
/mil: 1 mil-25,4μ).

The tensile test was performed according to ASTM D-638 at a tensile rate of 5
It was run at crn/min.

The melt viscosity was measured using a melt viscoelasticity measuring device manufactured by Leonodric at a temperature of 230°C and varying the shear rate. [η] was determined from this measurement result.

Example 1 Preparation of catalyst component (1) Commercially available magnesium jetoxide 58f and anhydrous magnesium chloride 481 were mixed in a nitrogen gas atmosphere in a stainless steel (SUS 32) After co-pulverizing by shaking for 2 hours,
Hexachloroethane 52 y CMg(ogt)z/
Mgctz/OzC! t6 (molar ratio) - t o /
to/0.24] and co-pulverized for 15 hours to obtain a co-pulverized product.

The co-pulverized product 12f obtained above was treated in a nitrogen gas atmosphere,
Put it in a 500 m flask and add 200 m of toluene to it.
1 and 100 ml of titanium tetrachloride, and heated at 110°C for 2 hours.
After stirring and contacting for a period of time, excess liquid was removed. Next, the solid material was washed six times with 100 rM n-heptane at 65°C and dried under reduced pressure at 50°C for 1 hour to obtain a solid component (1) with a titanium content of Z8%.

This solid component (1) s, o r was replaced with nitrogen.
, put it in a 6t autoclave and add 150rn of n-heptane! , to make a slurry. While stirring this slurry at 150 revolutions/min, ethylene was introduced to bring the solid component (1) into contact with the ethylene, and the pressure of the autoclave was set at 1.2 Kq/cm2G. After that, a solution of 1.1 mmol of diethylaluminium chloride dissolved in n-heptane was added, and the system temperature was raised to 40.
Adjust the autoclave pressure to 1.2℃/
Ethylene was continuously supplied to react so that crn2G was obtained. After about 10 minutes, purge unreacted ethylene,
The gas phase was replaced with total nitrogen gas. After that, stirring was stopped, and the catalyst components were allowed to settle and separate from the slurry.
The catalyst component (1) was obtained by washing with 4 ml of n-hebutane.

Stainless steel (SUS) with an internal volume of 1.51 and equipped with an ethylene copolymerization stirrer
52) in an autoclave under nitrogen gas atmosphere.
Catalyst component (1) 12■, triisobutylaluminum 0
．． 7 mmol and 7 o of isobutane.

ml, and the temperature of the polymerization system was raised to 75°C. Next, hydrogen gas was introduced so that the hydrogen partial pressure became l 2 f/crtt2, then ethylene was introduced until the ethylene partial pressure became 3.0 Ky/1 m 2 , and 151 1-butene was further added.

Polymerization was carried out for 22 minutes while continuously supplying ethylene to keep the total pressure of the polymerization system constant. The result is 1o11
of polymer was produced.

Subsequently, the second stage polymerization was carried out by changing the reaction conditions.

That is, hydrogen was introduced so that the hydrogen partial pressure became 43 Kg/cm2, 15 f of 1-butene was added, and ethylene was introduced until the ethylene partial pressure became 3 Ky/cm2.

Polymerization was carried out for 99 minutes while continuously supplying ethylene to keep the total pressure of the polymerization system constant. After the polymerization was completed, isobutane in the polymerization system, unreacted ethylene, and 1-butene were removed to form a white powder. A polymer of the form was separated. The polymer was dried under reduced pressure at 70°C for 10 hours to give Mll, 2y/
1o min, BDo, 30ri/c7n3, density 0.918
? /Cm3, 2027 ethylene-1-butene copolymers with [η]26 were obtained.

The polymerization results and the evaluation results of the obtained copolymers are shown in Tables 1 and 2.

Examples 2 to 5 Ethylene copolymerization was carried out in the same manner as in Example 1 except that the ethylene copolymerization conditions were as shown in Table 1, and the results are shown in Tables 1 and 2.

Example 6 Example 1 except that 0.15 mmol of diethyl ether as an electron donating compound was added during copolymerization of ethylene.
Copolymerize ethylene in the same manner as above, and use the results as the first
It is shown in Table and Table 2.

Example 7 Preparation of catalyst component (2) 1.16 kg of commercially available magnesium jetoxide and 0.96 kg of anhydrous magnesium chloride were mixed in a nitrogen gas atmosphere in a stainless steel (SUS32) M ball 9800 with a diameter of 12.
Stainless steel (SUS 52) with an internal volume of 221
) and co-pulverized by shaking for 7 hours.
g(OEt)2 / Mg04 / (4C!4 (molar ratio) = t o / t o / 0.24) was added and co-pulverized for 15 hours.The obtained co-pulverized product 2.5K9 In a nitrogen gas atmosphere, the mixture was placed in a 50 t stainless steel (BUS32) reaction vessel equipped with a stirrer, 11.5 kg of toluene and 11.2 kg of titanium tetrachloride were added thereto, and the mixture was stirred at 105°C for 2 hours. After contacting, excess liquid was removed.The solid material was then washed 6 times with 20 portions of n-hebutane at 65 DEG C. to obtain a solid component.

This solid component 3K9 was slurried with n-heptane, placed in a Sat stainless steel reactor equipped with a stirring opportunity, and ethylene was introduced while entraining at 100 rpm.
The solid component and ethylene are brought into contact, and the pressure in the reaction vessel is reduced to 1
．． 2 K97cm2G was set. After this, add 100 ml of 100 mmol of diethyl aluminum chloride!
was added as an n-hebutane solution, and while adjusting the system temperature to 40°C, the pressure in the reaction vessel was increased to 1.2 g/cm2G.
Ethylene is continuously supplied so that the solid component 12
0477 ethylene was reacted. After the reaction was completed, unreacted ethylene was immediately purged and the gas phase was replaced with nitrogen gas (3).Then, stirring was stopped, and the catalyst components were separated from the slurry by sedimentation. −
The catalyst component (2) was obtained by washing with hebutane four times.

A first stage reaction vessel made of stainless steel with an internal volume of 100 tons for copolymerization of ethylene was filled with isobutane, and wasobutane was added at a rate of 120 tons/hour, triisobutylaluminum at a rate of 120 mmol/hour, and catalyst component (2) at a rate of '5.01/hour. 1 at 75° C. while continuously discharging the contents of the reaction vessel.
1:2Kg of diethylene per hour, 14Nt of hydrogen, 1-
Butene was fed at a rate of 1.3 K9 and polymerization was carried out continuously (average residence time 1 hour). The pressure of the reaction vessel was maintained at 42 Ky/1yn2G. The hydrogen/ethylene (mole ratio) in the liquid phase is o, 02.1-butene/ethylene (
molar ratio) was 045. The amount of polymer produced in the first stage was 50% by weight of the total polymer.

The reaction product extracted from the first stage was supplied as it was to a stainless steel second stage reaction vessel having an internal volume of 200 t due to the pressure difference between the first stage and the second stage.

The second stage reaction vessel was also filled with imbutane, and without feeding any new catalyst, wasobutane was added at 47 t/h, ethylene at 12.5 [y/h, hydrogen at a 7 Nm'' for 7 h, and 1-butene at 2.0 t/h. Supply at a rate of 6Kq/hour, 75
Polymerization was carried out continuously at a temperature of 1.0 hours at an average residence time of 1.0 hours so that the amount of polymer produced in the second stage was 50 weight tel of the total polymer. The second stage polymerization pressure is 41Kg
/cm2G/ζ5. The hydrogen/ethylene (molar ratio) in the liquid phase was 0.30.1-butene/ethylene (molar ratio) 0.65. The reaction product from the second stage was continuously withdrawn and dried after flashing off the isobutane. Polymerization was carried out continuously for 150 hours, but stable operation continued with no visible damage to the container or other parts.

The physical properties and evaluation results of the obtained ethylene copolymer are shown in Table 2. The specific activity of the catalyst was 4580 in the first stage and 1.710 in the second stage. Also, the M engineering IC of polyethylene produced in the first stage is 1,0016? /10 minutes, density fi 0.9
It was 22 f'/crn3.

Comparative Examples 1 to 6 Ethylene copolymerization was carried out using catalyst component (1) under the conditions shown in Table 1 in the same manner as in Example 1, and the results are shown in Tables 1' and 2. However, in Comparative Example 1, the amount of hydrogen used in the second stage was reduced to lower the M factor, and in Comparative Example 3, the M factor in the first stage was increased, so the molecular weight distribution was not sufficiently widened in both cases. The fluidity shown by [η] is not good.

Furthermore, in Comparative Example 2, the EScR was significantly reduced due to the high density of the copolymer.

Examples 8 and 9 The solid component (1) prepared in Example 1 was converted into the catalyst component (3).
Copolymerization of ethylene was carried out in the same manner as in Example 1 under the conditions shown in Table 1. The results are shown in Tables 1 and 2.

Example 10 When preparing catalyst component (1) in Example 1, catalyst component (4) prepared in the same manner as in Example 1 except that magnesium chloride was not used was used, and the catalyst components shown in Table 1 were prepared. Ethylene copolymerization was carried out under the same conditions as in Example 1. The results are shown in Tables 1 and 2.

Example 11 During the preparation of the catalyst component (4) in Example 10, the solid component obtained without pretreatment was used as the catalyst component (5), and the same procedure as in Example 1 was carried out under the conditions shown in Table 1. The results are shown in Table 1 and Section 2. Comparative Example 4 Commercially available magnesium jetoxide 201i+ was copolymerized with Example 1.
The mixture was placed in the same mill pot and shaken for 15 hours. The obtained pulverized product 121 was mixed with titanium tetrachloride 5 in the presence of toluene.
Contact was carried out by stirring at 0 m and 110° C. for 2 hours. Excess liquid was removed, washed 6 times with n-hexane, and dried to prepare catalyst component (6). 5. Copolymerization of ethylene Using the catalyst component (6) obtained above, the first Ethylene copolymerization was carried out in the same manner as in Example 1 under the conditions shown in the table.

The results are shown in Tables 1 and 2.

Comparative Example 5 Preparation of Catalyst Component (7) Anhydrous magnesium chloride 201 and titanium tetrachloride 61 were placed in the mill pot used in Example 1 and shaken for 15 hours. In the presence of toluene, 100-
of pyridine was added dropwise. After stirring at 80°C for 2 hours, 2
A solution of 0rd triisobutylaluminum dissolved in toluene was gradually added dropwise. After the dropwise addition, the temperature was raised to 60°C, and contact was carried out by stirring for 2 hours. Excess liquid was removed, washed six times with n-hexane, and then dried to prepare catalyst component (7).

Ethylene Copolymerization Ethylene copolymerization was carried out in the same manner as in Example 1 using the catalyst component (7) obtained above under the conditions shown in Table 1.

The results are shown in Tables 1 and 2.

Claims (1)

[Scope of Claims] 1) In the presence of a catalyst component made by contacting a magnesium alkoxide, a hydrogenated hydrocarbon, and a titanium compound, and a catalyst made of an organoaluminum compound, Copolymerize and
Melt index 0.001-1v/10min, density 0
．． In the second stage, ethylene and α-olefin are copolymerized in the presence of the polymer with a melt index of 0. .01~sop/1o min, 260
Shear rate at ° 0.1 racL 7 seconds and 500 ra
a Ratio η of melt viscosity at 7 seconds. ,! /ηsoo
value converted to melt index 1 f/10 min (ηo, 1/η50G) M knee 1 is 20 or more, density Q, 910 to 0.94017 cm3 of ethylene and α
- A method for producing a copolymer of olefins. 2) The method according to claim 1), which comprises carrying out the copolymerization in an inert hydrocarbon.