JPH05202140A - Production of ethylene copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer from ethylene and an alpha-olefin using a new catalytic system. CONSTITUTION:The objective copolymer having excellent physical properties can be obtained by stable polymerization using a catalytic system. This catalytic system is made up of (A) an organoaluminum component and (B) a solid component which can be prepared by the following method: a carrier, a reaction product of an aluminum halide, silicon compound and Grignard compound, are treated with a non-reductive compound followed by carrying a titanium compound and then successive treatment with an electron donor and an organometallic compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a copolymer of ethylene and α-olefin.

[0002]

2. Description of the Related Art Copolymerization of ethylene with .alpha.-olefins using a Ziegler-Natta type catalyst has hitherto been carried out by polymerization methods such as solution polymerization, bulk polymerization, slurry polymerization and gas phase polymerization. In recent years, a process in which the step of increasing the catalyst activity and separating the catalyst residue from the produced copolymerization is not required has become widespread, and for the purpose of preparing catalyst particles having high catalyst activation and good fluidity, an inorganic solid, Furthermore, titanium is added to the inorganic solid having a specific particle size.
Many highly active catalysts carrying a transition metal component such as vanadium have been disclosed. Japanese Patent Publication No. 54-129983, 5
No. 8-17206, No. 59-49242, Japanese Patent Fair 2-
In each of the publications of No. 33045, there is proposed a supported high activity catalyst for copolymerization of ethylene and α-olefin with which the present invention is concerned. When a copolymer of ethylene and α-olefin is produced by fluidized bed gas phase polymerization, a low molecular weight component having adhesiveness is produced, the fluidity of polymer particles is deteriorated, and therefore a lump of polymer is produced. Or the reaction tube may be blocked. In addition, if the randomness of the α-olefin in the copolymer is poor, that is, if the distribution of the α-olefin units is biased, a tacky copolymer is produced and the same problems as described above occur. Therefore, a stable copolymerization reaction for a long period of time cannot be performed.

Generally, in the copolymerization of ethylene and α-olefin, a copolymer having a lower density can be produced by increasing the content of α-olefin. However, when the low molecular weight component is generated in the polymerization reaction or the composition distribution of α-olefin in the copolymer becomes wide, that is, when the composition between polymer chains is not uniform, the surface of the molded film has tackiness. However, if the copolymer has a wide molecular weight distribution, the mechanical strength is lowered, and a thinner film cannot be produced. In the copolymerization of ethylene and α-olefin, in order to solve the above problems, in particular,
In order to narrow the composition distribution and suppress the formation of low molecular weight components, Zr-based catalysts (JP-A-62-121707, JP-A-62-121707 and JP-A-62-121207).
-121709, JP-A-3-234712, 3-
No. 223306, No. 3-217404), or
Use of electron donors in magnesium compound-supported catalysts (JP-A-61-271309, JP-A-61-271310,
No. 63-159411, No. 63-142008, No. 63-117019, and Japanese Patent Publication No. 1-49296) are proposed. However, the conventional techniques are not always satisfactory in terms of production and physical properties of the above-mentioned copolymer, and further improvement is desired.

[0004]

DISCLOSURE OF THE INVENTION The present invention improves the problems in the process for producing a copolymer of ethylene and an α-olefin, and particularly in the case of producing by a fluidized bed gas phase polymerization, a long-term stable polymerization reaction. And a method for producing a copolymer having excellent physical properties.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to aluminum halide and a compound of the formula R ¹ _m Si (OR ² ) _4-m (wherein R ¹ is an alkyl group having 1 to 8 carbon atoms or a phenyl group And R ² represents an alkyl group having 1 to 8 carbon atoms,
m is 0, 1, 2, or 3), in the reaction product with the organosilicon compound represented by the formula, R ³ MgX ¹ (wherein, R ³ represents an alkyl group having 1 to 8 carbon atoms, X ¹
Represents a halogen atom), and a carrier obtained by reacting the Grignard compound with the formula MX ² _p (OR ⁴ ) _q R ⁵ _r (wherein M is aluminum, magnesium, boron,
Represents silicon, carbon, or phosphorus, R ⁴ and R ⁵ represent an alkyl group having 1 to 8 carbon atoms or a phenyl group, and X ²
Represents a halogen atom, and p, q and r are p + q ≧ 1.
And r ≧ 0 and n is a valence of M, n =
After contact with the non-reducing compound represented by satisfying _{p + q + r), 4} -s ( wherein the formula _{^{Ti (OR 6) s X 3}} , R 6 is an alkyl group or phenyl group having 1 to 8 carbon atoms X ³ represents a halogen atom, s represents 0, 1,
2, 3 or 4), and a solid catalyst component (A) obtained by sequentially contacting a solid obtained by contacting the titanium compound with an electron donor and an organometallic compound. The present invention relates to a method for producing an ethylene copolymer, which comprises copolymerizing ethylene and an α-olefin in the presence of a catalyst obtained from the organoaluminum compound component (B).

Hereinafter, each component used in the preparation of the catalyst of the present invention and its conditions will be described in detail. In the present invention, the preparation and polymerization of the catalyst component are all carried out under an atmosphere of an inert gas such as nitrogen or argon. Further, it is desirable that the raw material for preparing the catalyst component is substantially anhydrous.

Specific examples of the aluminum halide in the present invention include aluminum chloride, aluminum bromide and aluminum iodide, and among them, aluminum chloride is preferably used.

Specific examples of the organosilicon compound represented by the formula R ¹ _m Si (OR ² ) _4-m include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, Tetra-isopentoxysilane, tetra-n-hexoxysilane, methyltrimethoxysilane, methyltriethoxysilane,
Methyltri-n-butoxysilane, methyltriisopentoxysilane, methyltri-n-hexoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltriisopentoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, Isopentyl triethoxysilane, Isopentyl tri-n
-Butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, dimethyldiisopentoxysilane, diethyldiethoxysilane, diethyldiisopentoxysilane, diisobutyldiisopentoxysilane, di-n-butyldiethoxysilane , Diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethylisopropoxysilane, tri-n-propylethoxysilane, tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltri Ethoxysilane, phenyltriisobutoxysilane, phenyltriisopentoxysilane, diphenyldiethoxysilane, diphenyldiisopentoxysilane, diphenyldioctoxysilane Triphenyl silane,
Examples thereof include triphenylethoxysilane, triphenylisopentoxysilane, benzyltriethoxysilane, benzyltributoxysilane, and dibenzyldiethoxysilane. Of these, alkylalkoxysilanes such as methyltriethoxysilane are preferably used.

The proportion of aluminum halide used in the reaction between the aluminum halide and the organosilicon compound is
It is preferably 0.1 to 10 mol, and particularly preferably 0.1 to 2 mol, per mol of the organosilicon compound. The reaction is usually carried out by stirring both compounds in an inert organic solvent at a temperature in the range of -50 to 100 ° C for 0.1 to 2 hours. The reaction proceeds exothermically and the reaction product is obtained as a solution in an inert organic solvent. The reaction product is subsequently subjected to reaction with a Grignard compound as a solution in an inert organic solvent.

Examples of the inert organic solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane and dodecane, and alicyclic compounds such as cyclopentane, cyclohexane and methylcyclohexane. Hydrocarbons or aromatic hydrocarbons such as toluene, benzene, xylene, etc. may be mentioned. These inert organic solvents can be similarly used in the following step of preparing the catalyst solid component (A) or the polymerization step.

The Grignard compound represented by the formula R ³ MgX ¹ is preferably an alkylmagnesium chloride in which X ¹ is a chlorine atom, and specific examples thereof include methylmagnesium chloride, ethylmagnesium chloride and n-butylmagnesium. Examples thereof include chloride and n-hexyl magnesium chloride. The amount of the Grignard compound used is preferably 0.05 to 4 mol, particularly 1 to 3 mol, per mol of the aluminum halide used for preparing the reaction product.

The method of reacting the reaction product of the aluminum halide and the organosilicon compound with the Grignard compound is not particularly limited, but an inert solvent solution of the reaction product may be added to an ether solution of the Grignard compound or an ether and an aroma. It is convenient to carry out by gradually adding a mixed solvent solution with a group hydrocarbon or by adding them in the reverse order. Specific examples of ethers include diethyl ether, diisopropyl ether,
Examples thereof include di-n-butyl ether and diisoamyl ether.

The temperature of the reaction is usually -50 to 100 ° C,
It is preferably -20 to 25 ° C. The reaction time is not particularly limited, but is usually 5 minutes or longer. The carrier precipitates as the reaction progresses. The carrier thus obtained can be subjected to the following treatment as a reaction mixture, but after separating the carrier in advance and washing with an inert organic solvent,
It is preferably subjected to a contact treatment with a non-reducing compound represented by the following formula MX ² _p (OR ⁴ ) _q R ⁵ _r .

Specific examples of the non-reducing compound include aluminum chloride, aluminum chloride ethoxide, aluminum ethoxide, diethoxymagnesium, chloroethoxymagnesium, boron trichloride, ethoxyborondichloride, ethylborondichloride, and diethylboron chloride. , Tetramethoxysilane, tetraethoxysilane, tetra-n
-Propoxysilane, tetra-n-butoxysilane, tetraisopentoxysilane, tetra-n-hexoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, methyltriisopentoxysilane, methyltri-n -Hexoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltriisopentoxysilane, n-
Butyltriethoxysilane, isobutyltriethoxysilane, isopentyltriethoxysilane, isopentyltri-n-butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, dimethyldiisopentoxysilane, diethyldiethoxysilane, diethyl Diisopentoxysilane, diisobutyldiisopentoxysilane, di-n-butyldiethoxysilane, diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethylisopropoxysilane, tri-
n-propylethoxysilane, tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltriethoxysilane, phenyltriisobutoxysilane, phenyltriisopentoxysilane, diphenyldiethoxysilane, diphenyldiisopentoxysilane,
Diphenyldioctoxysilane, triphenylmethoxysilane, triphenylethoxysilane, triphenylisopentoxysilane, benzyltriethoxysilane, benzyltributoxysilane, dibenzyldiethoxysilane, trimethoxychlorosilane, triethoxychlorosilane, tri- n-Butoxycyclosilane, ethyldiethoxychlorosilane, methyldiethoxychlorosilane, ethyldiisopropoxycyclosilane, ethyldi-n-butoxycyclosilane, dichlorodiethoxysilane, dichlorodi-n-butoxysilane, dichlorodiisopentoxy Silane, diethylethoxychlorosilane, trichloromethoxysilane, trichloroethoxysilane, trichloroisobutoxysilane, dimethylisopropoxycyclolsilane, tetrac Rushiran, tetrachloromethane, and the like phosphorus trichloride.

Among them, silane compounds such as chlorosilane and alkoxysilane can be preferably used. Among the compounds represented by the formula MX ² _p (OR ⁴ ) _q R ⁵ _r , aluminum and magnesium alkyl or phenyl compounds are reducing compounds and are excluded from the non-reducing compounds of the present invention.

The amount of the non-reducing compound used is preferably 1 mol or more, particularly 2 to 100 mol, per 1 mol of the Grignard compound used when preparing the carrier. The contact treatment between the carrier and the non-reducing compound can be performed by the following method. The carrier is contacted with the non-reducing compound in the presence or absence of an organic solvent at a temperature of 20 to 200 ° C., preferably 60 to 140 ° C. for 0.5 to 3 hours, after which the reaction mixture is removed. Separate the solid and wash with organic solvent as needed.

Examples of the organic solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane and dodecane, and alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane. , Or toluene, benzene,
Examples thereof include aromatic hydrocarbons such as xylene, diethyl ether, diisopropyl ether, di-n-butyl ether, diisoamyl ether. This contact treatment can be continuously performed multiple times.

The solid obtained by the contact treatment with the carrier and the non-reducing compound thus obtained can be subjected to the following contact treatment with the titanium compound. Specific examples of titanium compounds include methoxytrichlorotitanium, dimethoxydichlorotitanium, trimethoxychlorotitanium, ethoxytrichlorotitanium, diethoxydichlorotitanium, propoxytrichlorotitanium, dipropoxydichlorotitanium, butoxytrichlorotitanium, dibutoxydichlorotitanium. , Phenoxytrichlorotitanium, diphenoxydichlorotitanium, methoxytribromotitanium, phenoxytribromotitanium, methoxytriiodotitanium, phenoxytriiodotitanium, tetrachlorotitanium, tetrabromotitanium, tetraiodotitanium, tetramethoxytitanium, tetraethoxytitanium , Tetrapropoxy titanium and the like.

Among them, tetrachlorotitanium, methoxytrichlorotitanium, dimethoxydichlorotitanium, ethoxytrichlorotitanium, diethoxydichlorotitanium, propoxytrichlorotitanium, dipropoxydichlorotitanium,
Butoxytrichlorotitanium and dibutoxydichlorotitanium are preferably used. Two or more kinds of these titanium compounds may be used in combination.

The amount of the titanium compound used is preferably 1 mol or more, particularly 2 to 100 mol, per 1 mol of the Grignard compound used when preparing the carrier. The contact treatment with the titanium compound can be performed by the following method. The contact-treated solid of the carrier and the non-reducing compound,
20 to 20 in the presence or absence of an inert organic solvent
0.5 to 3 at a temperature of 0 ° C., preferably 60 to 140 ° C.
Contact with the titanium compound for a period of time, after which the solid is separated from the reaction mixture and optionally washed with an inert organic solvent. The contact treatment with the titanium compound can be continuously performed a plurality of times. The solid obtained by the contact treatment with the carrier and the titanium compound thus obtained can be subjected to the following contact treatment with the electron donor.

The electron donor used in the present invention includes organic acid esters, inorganic acid esters, acid halides,
Ethers, acid amides, N, N-dialkyl acid amides, amines, nitriles, acid anhydrides, alkoxysilanes, ketones, alcohols, aldehydes, carboxylic acids, isocyanates and the like can be used.

Specific examples of the organic acid esters include methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate and dichloro. Ethyl acetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, toluic acid Methyl, amyl toluate, ethyl ethyl benzoate, methyl anisate, n-butyl maleate, diisobutyl methylmalonate, di-n-hexyl cyclohexenecarboxylic acid, diethyl nadic acid, diisopropyi tetrahydrophthalate, phthalic acid Ethyl, diisobutyl phthalate, di -n- butyl phthalate, di-2-ethylhexyl, diheptyl phthalate, .gamma.-butyrolactone, .delta.-valerolactone, coumarin, phthalide, and the like ethylene carbonate.

Specific examples of acid halides include acetyl chloride, toluic acid chloride, anisic acid chloride and the like. Specific examples of ethers include diisopropyl ether, dibutyl ether, diamyl ether, tetrahydrofuran, anisole, diphenyl ether epoxy-p-menthane and the like. Specific examples of the acid amides include acetic acid amide, benzoic acid amide,
Examples thereof include toluic acid amide. Specific examples of N, N-dialkylamides include dimethylformamide,
Examples thereof include dimethylacetamide.

Specific examples of amines include methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline and tetramethylenediamine. Specific examples of nitriles include acetonitrile,
Examples thereof include benzonitrile and tolunitrile. Specific examples of the acid anhydride include acetic anhydride, phthalic anhydride, benzoic anhydride and the like.

Specific examples of the alkoxysilanes include tetramethoxysilane, tetraethoxysilane and tetra-silane.
n-propoxysilane, tetra-n-butoxysilane,
Tetraisopentoxysilane, tetra-n-hexoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, methyltriisopentoxysilane, methyltri-n-hexoxysilane, ethyltriethoxysilane, ethyltriisobromine Poxysilane, ethyltriisopentoxysilane, n
-Butyltriethoxysilane, isobutyltriethoxysilane, isopentyltriethoxysilane, isopentyltri-n-butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, dimethyldiisopentoxysilane, diethyldiethoxysilane, Diethyldiisopentoxysilane, diisobutyldiisopentoxysilane, di-n-butyldiethoxysilane, diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethylisopropoxysilane, tri-
n-propylethoxysilane, tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltriethoxysilane, phenyltriisobutoxysilane, phenyltriisopentoxysilane, diphenyldiethoxysilane, diphenyldiisopentoxysilane,
Diphenyldioctoxysilane, triphenylmethoxysilane, triphenylethoxysilane, triphenylisopentoxysilane, benzyltriethoxysilane, benzyltributoxysilane, dibenzyldiethoxysilane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxy Examples thereof include silane, 2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, and tricyclopentylethoxysilane.

Specific examples of the ketones include methyl ethyl ketone, acetylacetone, methyl isobutyl ketone,
Examples include acetophenone and benzophenone. Specific examples of alcohols include methanol, ethanol, propanol, butanol, hexanol, octanol, dodecanol, and benzyl alcohol.

Two or more kinds of these electron donors may be used in combination. Further, the contact-treated solid of the carrier and the titanium compound may be subjected to the contact treatment by using the electron donor stepwise twice or more. The amount of the electron donor used is preferably 1 to 50% by weight, and more preferably 5 to 30% by weight, based on the solid treated by contact between the carrier and the titanium compound. The contact treatment method with an electron donor is preferably carried out in an inert organic solvent at a temperature of 0 to 200 ° C, particularly 5 to 150 ° C. The time is not particularly limited, but usually 5 minutes or more. The thus obtained contact-treated solid with an electron donor can be subjected to the following contact treatment with an organometallic compound.

Examples of the organometallic compound include alkyl lithium, dialkyl magnesium, alkyl magnesium halide, dialkyl zinc, trialkyl aluminum,
Although dialkyl or monoalkyl aluminum halides can be used, trialkyl aluminum is preferable, and specific examples thereof include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum and the like. Any of the above organometallic compounds can be used as a mixture. Also,
Polyaluminoxane obtained by the reaction of alkylaluminum and water can be used as well.

Two or more kinds of these organometallic compounds may be used in combination. Further, the titanium compound-treated carrier may be contact-treated by using the organometallic compound stepwise twice or more.

The amount of the organometallic compound used is preferably such that the metal / Ti molar ratio is 0.1 to 1000, particularly 0.5 to 500, relative to the titanium atom in the titanium compound-treated carrier. As a contact treatment method with an organometallic compound,
In an inert organic solvent, the reaction temperature is preferably 0 to 100 ° C., particularly 5 to 60 ° C., and the contact time is not particularly limited, but is usually 5 minutes or longer.

The Ti valence in the titanium compound-supported solid is reduced to less than 4 by the organometallic compound. Therefore,
By using the solid catalyst component (A) treated with an organometallic compound, the polymerization activity does not change significantly at the initiation of polymerization, the control of the polymerization reaction is facilitated, and an ethylene copolymer can be obtained with high catalyst efficiency. it can. The component (A) is separated from the thus-obtained mixture containing the treated solids by filtration, decantation, etc., and washed with an inert organic solvent if necessary. As the inert organic solvent, the same one as used in the treatment with the titanium compound can be used. The solid catalyst component (A) obtained by the above method can be used together with the organoaluminum compound (B) for the polymerization reaction.

Specific examples of the organoaluminum compound component (B) include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, diethyl aluminum chloride,
Dibutyl aluminum chloride, diethyl aluminum bromide, ethyl aluminum sesquichloride, ethyl aluminum sesquibromide, ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dichloride, ethyl aluminum dibromide,
Propyl aluminum dibromide, butyl aluminum dibromide, diethyl aluminum hydride, dibutyl aluminum hydride, ethyl aluminum dihydride, propyl aluminum dihydride, butyl aluminum dihydride, ethyl aluminum ethoxy chloride, ethyl aluminum butoxycyclolide, ethyl aluminum ethoxy bromide, etc. Be done. Also, isopropenylaluminum obtained by the reaction of diisobutylaluminum hydride and isoprene can be used. Further, for example, an alkylalumoxane obtained by a reaction of trialkylaluminum with water dispersed in a solvent or a reaction of water of crystallization of an inorganic compound can be used. Among them, trialkyl aluminums such as triethyl aluminum and triisobutyl aluminum are preferably used.

The amount of the organoaluminum compound component (B) used is usually 1 to 1000 mol per 1 gram atom of titanium in the solid catalyst component (A). In addition, two or more kinds of organoaluminum compounds can be used together.

In the present invention, ethylene and α-olefin are copolymerized by using a catalyst composed of the components (A) and (B). Specific examples of α-olefins include:
Propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1 and the like can be mentioned.

In the present invention, if necessary, the catalyst comprising the components (A) and (B) may be prepolymerized with ethylene or a mixture of ethylene and α-olefin. When carrying out the prepolymerization, it is preferred to carry out the polymerization until a particulate polymer containing 0.0125 to 0.04 mmol of Ti atoms per gram of the prepolymer is obtained. An inert organic solvent may be used as a polymerization solvent, or a liquid α-olefin itself may be used.

As a preferable condition for producing the prepolymer, the polymerization pressure is usually atmospheric pressure to 10 kg / cm.
^{2. The} polymerization temperature is 100 ° C. or lower, usually 20 to 70 ° C. The polymerization time is usually 30 minutes to 15 hours, preferably 2 to
10 hours. The ratio of the component (A) and the component (B) in the prepolymerization or the main polymerization described later is the molar ratio of Ti and Al, and is usually Al / Ti = 0.1-1.
000, preferably 0.5 to 200. When an excessive amount of the component (B) is used in the prepolymerization, the copolymer can be produced without additionally using the component (B) in the main polymerization. The prepolymer is a polymerization solvent, for example, evaporated with inert gas, dried and removed to obtain a powder,
It can be subjected to main polymerization.

The main polymerization reaction can be carried out in the same manner as the α-olefin polymerization reaction using a conventional Ziegler-Natta type catalyst. The main polymerization reaction can be carried out in the liquid phase or the gas phase using the solid catalyst component (A) or the prepolymer.
Examples of the gas phase polymerization reaction include a fluidized bed polymerization method and a stirring polymerization method.

In particular, when performing the fluidized bed polymerization method, it is possible to copolymerize gaseous ethylene and α-olefin in the fluidized bed polymerization reactor in the presence of the prepolymer produced as described above. preferable. The α-olefin used in the main polymerization may be the same as or different from that used in the preparation of the prepolymer. In the main polymerization, at the same time that the prepolymer is fluidized by the monomer gas,
The heat of polymerization is removed by the monomer gas, usually 50 to 1
Polymerization is carried out at 10 ° C. In the main polymerization, when a prepolymer is used as a catalyst, an organoaluminum compound (B) can be used together.

When the polymerization reaction is carried out in a liquid phase, an inert organic solvent may be used as a polymerization solvent, or a liquid α-olefin itself may be used. The concentration of the catalyst in the polymerization solvent is not particularly limited, but generally 1 L of the polymerization solvent is used.
Therefore, the solid catalyst component (A) is 0.001 to 1 milligram atom in terms of titanium metal, and the organoaluminum compound component (B) is 0.01 to 100 mmol.

The polymerization reaction is carried out with water and oxygen substantially removed. The polymerization temperature is usually 30 to 100 ° C., and the polymerization pressure is usually 1 to 80 Kg / cm ² . Further, hydrogen can be made to coexist as a molecular weight regulator of the produced polymer.

[0041]

According to the present invention, in particular, in the fluidized bed gas phase polymerization method, since the polymerization activity is high, a deashing step of the produced copolymer is unnecessary. Furthermore, the proportion of low-molecular-weight tacky products is small, and since there is almost no formation of an α-olefin block copolymer by copolymerization, good polymer fluidity is maintained in the present polymerization method, and the particles are kept together. It is possible to stably carry out the polymerization reaction for a long period of time without the formation of agglomerates and the attachment to the reactor. In addition, since the produced copolymer has a narrow composition distribution and molecular weight distribution, even if the α-olefin content is increased and the density is reduced, the surface tackiness of the molding film is small, and the mechanical strength of the molding is low. It has excellent physical properties such as being large.

[0042]

EXAMPLES Examples and comparative examples of the present invention will be described below. In the examples, the “polymerization activity” is a copolymer yield (kg) per 1 g of Ti component of the solid catalyst used in the polymerization reaction. "MI" means ASTM D-1
190 under a load of 2.16 kg / cm ² according to 238
It is the melt index of the polymer measured at ° C. The titanium content of the catalyst solid component was measured by a colorimetric method. The molecular weight distribution was determined by GPC using polystyrene as a standard substance, was evaluated by the ratio of the number average molecular weight M _w and the weight average molecular weight M _n M _{w /} M _n. The content of α-olefin was measured by NMR. Density was measured by a density gradient tube. The composition distribution of the copolymer was evaluated by the relationship between the α-olefin content and the density. That is, in general, α
For the same olefin content, the more random the copolymer, the smaller the density and therefore the narrower the composition distribution.

Example 1 (1) Preparation of solid catalyst component Toluene suspension 4 containing 15 mmol of anhydrous aluminum chloride
After adding 15 mmol of methyltriethoxysilane to 0 ml and reacting at 25 ° C. for 0.5 hours, the temperature was raised to 60 ° C. and further reaction was performed for 1 hour. The reaction product mixture was cooled to −5 ° C., 18 ml of a solution of 30 mmol of n-butylmagnesium chloride in diisopropyl ether was added to the reaction product mixture in 0.5 hours, and then the temperature was raised to 30 ° C. and the reaction was carried out for 1 hour. The precipitated solid was filtered off and washed with toluene. 30 ml of a toluene suspension containing 4.90 g of the obtained solid.
To the above, 10 ml of tetrachlorosilane was added, and contact treatment was performed at 40 ° C. for 1 hour. The contact-treated solid was filtered off at 90 ° C. and washed with 30 ml of toluene three times. 4.90 g of the obtained carrier
30 ml of toluene suspension of tetrachlorotitanium 15
0 mmol was added and contact treatment was carried out at 90 ° C. for 1 hour. The contact-treated solid was filtered off at 90 ° C. and then washed 3 times with 30 ml of toluene. Next, 1.2 mmol of di-n-heptyl phthalate was added to 30 ml of the obtained suspension of the contact-treated solid in toluene, and contact-treated at 90 ° C. for 1 hour. The treated solid was filtered off at 90 ° C. and then washed 3 times with 30 ml of toluene. To 30 ml of the toluene slurry of the contact-treated solid obtained above, triethylaluminum was added to Al / T.
It was introduced so that the i molar ratio was 10, and contact treatment was carried out at 40 ° C. for 1 hour. The treated solid is filtered off, then n-heptane 3
After washing 5 times with 0 ml, a slurry of 80 ml of n-heptane was prepared. The titanium content of the solid catalyst component was 3.98% by weight.

(2) Prepolymerization 800 ml of heptane was added to a 2 L autoclave made of SUS and purged with nitrogen gas, and 10.0 mmol of tri-n-octylaluminum and catalyst solid (Ti = 2.5 mmol) were introduced. After 1.5 kg / cm ² of hydrogen was injected under pressure, the temperature was raised to 60 ° C. and ethylene was introduced to initiate polymerization. Maintained at 68 ° C during polymerization, ethylene flow rate was 0.93
L / min. Polymerize for 2 hours as 0.0
A prepolymer containing 18 mmol Ti atoms was obtained.

(3) Gas phase copolymerization of ethylene with 1-butene 500 g of polyethylene powder prepared in advance has a diameter of 2
0 cm, 50 cm in length stirring type gas phase polymerization reactor,
While stirring the powder at 300 rpm, ethylene / butene-1 / hydrogen (3
/1/0.2 molar ratio) of the mixed gas at 45 ° C of 20 cm /
It was raised at a speed of sec and circulated. The copolymerization is carried out by introducing the prepolymer produced in (2) above at 10 g / hour,
Polymerization temperature about 75 to 85 ° C, polymerization pressure 2 kg / cm ² , A
It was carried out continuously for 10 hours at an atomic ratio of 1 / Ti of 10. During that time, ethylene / butene-1 copolymer was continuously extracted,
The activity and physical properties were evaluated. The results are shown in Table 1.

Example 2 The molar ratio of the mixed gas in the main polymerization was changed to (ethylene / butene-1).
/Hydrogen=2/1/0.2 molar ratio)
An ethylene / butene-1 copolymer was obtained in the same manner as in. The results are shown in Table 1.

Examples 3 and 4 The solid catalyst component was prepared under the same conditions and method as in Example 1 except that ethyl benzoate was used instead of di-n-heptyl phthalate, and the titanium content was determined. To obtain 4.10% by weight of a solid catalyst component (A). Then, prepolymerization was carried out in the same manner to obtain a prepolymer containing 0.017 mmol of Ti atom per gram. Further, copolymerization was carried out under the same conditions and methods as in Examples 1 and 2 to obtain ethylene /
A butene-1 copolymer was obtained. The results are shown in Table 1.

Examples 5 and 6 Solid catalyst components were prepared under the same conditions and methods as in Example 1 except that trioctylaluminum was used in place of triethylaluminum, and the titanium content was 4.21.
% Solid catalyst component (A) was obtained. Then, prepolymerization was carried out in the same manner to obtain a prepolymer containing 0.018 mmol of Ti atom per gram. Further, copolymerization was carried out under the same conditions and methods as in Examples 1 and 2 to obtain an ethylene / butene-1 copolymer. The results are shown in Table 1.

Examples 7 and 8 Solid catalyst components were prepared under the same conditions and methods as in Example 1 except that dimethylformamide was used instead of di-n-heptyl phthalate, and the titanium content was 4.13% by weight of solid catalyst component (A) was obtained. Then, prepolymerization was carried out in the same manner to obtain a prepolymer containing 0.017 mmol of Ti atom per gram. Further, copolymerization was carried out under the same conditions and methods as in Examples 1 and 2 to obtain an ethylene / butene-1 copolymer. The results are shown in Table 1.

Comparative Examples 1 and 2, without treatment with tetrachlorosilane, and with di-phthalic acid
A solid catalyst component (A) having a titanium content of 5.50% by weight was obtained in the same manner as in Example 1 except that n-heptyl and triethylaluminum were not used. next,
Prepolymerization was performed in the same manner to obtain a prepolymer containing 0.019 mmol of Ti atom per gram. Further, copolymerization was carried out under the same conditions and methods as in Examples 1 and 2 to obtain an ethylene / butene-1 copolymer. The results are shown in Table 1.

As can be seen from the examples and the comparative examples, in the examples, both have the same composition and lower densities, butene-1 is randomly copolymerized with ethylene. Further, no production of adhesive particles due to butene chain or low molecular weight components was observed, and therefore the fluidity of the polymer particles was good.

[Brief description of drawings]

FIG. 1 is a flow chart showing a polymerization method of the present invention and a step of preparing a catalyst solid component used in the polymerization.

[Table 1]

Claims (1)

[Claims] 1. An aluminum halide and a formula R ¹ _m Si (OR ² ) _4-m (wherein R ¹ represents an alkyl group having 1 to 8 carbon atoms or a phenyl group, and R ² has 1 to 1 carbon atoms). 8 represents an alkyl group,
m is 0, 1, 2, or 3), in the reaction product with the organosilicon compound represented by the formula, R ³ MgX ¹ (wherein, R ³ represents an alkyl group having 1 to 8 carbon atoms, X ¹
Represents a halogen atom), and a carrier obtained by reacting the Grignard compound is represented by the formula MX ² _p (OR ⁴ ) _q R ⁵ _r (wherein M is aluminum, magnesium, boron,
Represents silicon, carbon, or phosphorus, R ⁴ and R ⁵ represent an alkyl group having 1 to 8 carbon atoms or a phenyl group, and X ²
Represents a halogen atom, and p, q and r are p + q ≧ 1.
And r ≧ 0 and n is a valence of M, n =
After contacting with a non-reducing compound represented by the formula: satisfying p + q + r), a compound represented by the formula: Ti (OR ⁶ ) _s X ³ _4-s (wherein R ⁶ is an alkyl group having 1 to 8 carbon atoms or a phenyl group) X ³ represents a halogen atom, s represents 0, 1,
2, 3 or 4), and a solid catalyst component (A) obtained by sequentially contacting a solid obtained by contacting the titanium compound with an electron donor and an organometallic compound. A method for producing an ethylene copolymer, which comprises copolymerizing ethylene and an α-olefin in the presence of a catalyst obtained from the organoaluminum compound component (B).