JPS6352656B2 - - Google Patents

Description

Detailed Description of the Invention The present invention uses a plurality of polymerization vessels to produce polyethylene by a continuous multistage polymerization method in which a low molecular weight polymer is produced in the first stage polymerization system and a high molecular weight polymer is produced in the second stage polymerization system. This relates to a manufacturing method.

In the present invention, polyethylene refers to ethylene homopolymers as well as other small amounts of α-olefins that can be copolymerized with ethylene, such as propylene,
It includes copolymers with butene-1, hexene-1, 4-methyl-pentene-1, or dienes such as butadiene and dicyclopentadiene.

In the fields of extrusion molding and blow molding, which are the main uses of polyethylene, polyethylene is required to have a high molecular weight (low melt index), appropriate strength, and easy processing. Polyethylene with a low melt index has excellent strength, but has the disadvantage of poor fluidity during molding. As a means to solve this problem, a method of expanding the molecular weight distribution has been adopted. Polyethylene with a narrow molecular weight distribution is suitable for injection molding, but it is desirable for polyethylene used in extrusion molding or blow molding to have a wide molecular weight distribution. When a polymer with a narrow molecular weight distribution is blow-molded, the extrusion pressure during molding increases excessively, making molding impossible, and the appearance of the product is significantly impaired due to the occurrence of streaks, avatars, and melt fractures. In the case of extrusion molding, an excessive increase in extrusion pressure, increased molding instability, etc. can have fatal adverse effects, significantly reducing commercial value. In order to solve these problems, by broadening the molecular weight distribution of the polymer, processing productivity can be improved and products with excellent appearance can be obtained.

Methods to expand the molecular weight distribution include adding a third component to the polymerization system, using a mixture of two types of organoaluminum compounds that are one component of the catalyst, and using catalysts with various polymerization active sites. However, it is not always easy to produce a polymer with a sufficiently wide molecular weight distribution. On the other hand, a multi-stage polymerization method is known as a means for controlling the molecular weight distribution widely and arbitrarily, but this method is not satisfactory. For example, by combining a supported catalyst component and an organometallic compound, a low-molecular polymer is created in the first stage, then the polymerization gas is released, and a high-molecular polymer is created in the second stage. A polymerization method is disclosed in JP-A-51-47079. This method has disadvantages in that it is a high-temperature dissolution polymerization with a polymerization temperature of 120 to 250°C, and that it requires the use of a sufficient amount of solvent to dissolve the polymer, so that the amount of solvent used is quite large. In addition, in the special public official publication 48-42716,
A method is disclosed in which after the first stage polymerization is completed, the polymerization system is opened to release gas in the gas phase, and the polymerization conditions are newly set to perform the second stage polymerization.
Such a batch method has extremely poor polymerization productivity.

The purpose of the present invention is to solve these conventional problems by carrying out the continuous multi-stage polymerization of polyethylene, which produces a low-molecular polymer in the first stage and a high-molecular polymer in the second stage, at low temperatures and in a small amount of solvent. The purpose is to obtain polyethylene with a wide molecular weight distribution.

The present inventors have conventionally developed reaction products (hereinafter referred to as We have been researching catalyst components using solid products (referred to as ) as supports. The solid product () prepared from this solid product (), an electron donor compound, and a transition metal compound was itself combined with an organoaluminum compound as a solid catalyst component to catalyze the polymerization of α-olefin. It is used in Although this catalyst itself does not give an ethylene polymer with a wide molecular weight distribution, it was found that it has various effects when used in continuous multi-stage polymerization, and as a result of further research, it was found that the use of the catalyst of the present invention is even more effective. They discovered this and completed the manufacturing method of the present invention.

The method for producing polyethylene by continuous multi-stage polymerization of the present invention comprises combining a trivalent metal halide compound and a divalent metal hydroxide, oxide, carbonate, a double salt containing these, or a hydrate of a divalent metal compound. The solid product () obtained by the reaction is reacted with a transition metal compound of group a or group a of the periodic table in the presence of an electron donor compound, and the solid product () thus obtained is further reacted with ( Group A) a group a or group a transition metal compound containing a halogen (hereinafter referred to as a halogen-containing transition metal compound) and (group B) a group a or group a transition metal compound not containing a halogen (hereinafter referred to as a halogen-free transition metal compound) In the presence of a catalyst obtained by combining an organic aluminum compound with a solid product obtained by reacting at least two transition metal compounds selected from at least one from each group of In a solvent, in a state where a gas phase exists at the top of the polymerization vessel, under the conditions of a polymerization temperature of 50°C to 120°C and a polymerization pressure of 5 to 70 kg/ ^cm2 , the molar ratio of ethylene to hydrogen in the gas phase of the polymerization vessel is Hydrogen is supplied at a ratio of 1:0.1 to 3.0, and ethylene is supplied at a ratio of 30 to 90% of the total ethylene supply.
Stage polymerization is carried out, and after the first stage polymerization is completed, the polymer suspended in the solvent is brought to a pressure range of 1 to 30 kg/cm ² lower than the first stage polymerization pressure, and at least a portion of the hydrogen dissolved in the solvent is removed. At least a portion of the separated hydrogen is returned to the first stage polymerization system, and then the suspended polymer is heated at a polymerization temperature of 30°C to 100°C and a polymerization pressure of 5 to 70 kg/kg in the presence of a gas phase. ^cm2 , hydrogen is supplied so that the molar ratio of ethylene to hydrogen in the gas phase of the polymerization reactor is 1:0.001 to 0.5,
It is characterized in that the second stage polymerization is carried out by supplying all ethylene. Further, if necessary, α-olefin can be supplied to the first and/or second stage polymerization system to produce a copolymer of ethylene and α-olefin. In that case, the sum of the molar ratios of ethylene and α-olefin and the molar ratio of hydrogen may be the molar ratio of the first stage and/or the second stage.

In the production method of the present invention, polymerization is started by supplying a catalyst to the first stage polymerization system, and the polymerization temperature is 50°C or higher and 120°C in a saturated hydrocarbon solvent with a gas phase present at the top of the polymerization vessel. Below, preferably
The first stage polymerization is carried out at a temperature of 70 to 100° C. and a polymerization pressure of 5 to 70 kg/cm ² , preferably 10 to 50 kg/cm ² . The molecular weight of the produced polymer is determined by the molar ratio of ethylene to hydrogen in the gas phase of the polymerization vessel being 1:0.1 to 3.0.
It is adjusted by supplying ethylene and hydrogen so that it falls within the range of . The amount of polymer produced is controlled by feeding 30 to 90% of the total ethylene feed.

After the first stage polymerization is completed, the polymer suspended in the solvent is brought to a pressure range 1 to 30 kg/cm ² lower than the first stage polymerization pressure, and the first stage polymerization system is run while dissolved in the solvent. At least a portion of the released hydrogen is extracted from the polymerization system. At least a portion of the removed hydrogen is returned to the first stage polymerization system for reuse. The above-mentioned low pressure zone is usually provided in the middle of each stage, but it can also be incorporated into either one of the polymerization systems. 1st
The drop pressure difference between the stage polymerization system and the low pressure zone is determined by the amount of hydrogen required in the second stage polymerization system.

The polymer suspended in the solvent from which most of the hydrogen has been removed is guided to the second stage polymerization system by a transfer means such as a transfer pump. Newly set polymerization temperature of 30℃ or less,
The second stage polymerization is carried out under conditions of preferably 40 to 90 kg/cm ² , preferably 10 to 50 kg/cm ² , and preferably 10 to 50 kg/cm 2 in the presence of a gas phase in the upper part of the polymerization vessel. The molecular weight of the produced polymer is adjusted by supplying ethylene and hydrogen so that the molar ratio of ethylene to hydrogen in the gas phase is within the range of 1:0.001 to 0.5, and the amount of produced polymer is adjusted by supplying ethylene and hydrogen. is adjusted by supplying ethylene at 10 to 70% of the total ethylene supply. Usually, the second stage molecular weighting is carried out using only hydrogen dissolved in a solvent, but it is also possible to supply fresh hydrogen.

In the production method of the present invention, the catalyst is normally supplied only to the first stage polymerization system, but it can also be supplied to the second stage polymerization system if necessary.

In the multi-stage continuous polymerization of the present invention, a plurality of polymerization vessels are usually connected in series, but a plurality of polymerization vessels are connected in parallel (or some of them are parallel) to form the first stage and/or
Alternatively, it is also possible to use a second stage polymerization system.

The solvent used in the polymerization process of the present invention is a saturated hydrocarbon having 4 to 15 carbon atoms, such as butane, pentane, hexane, heptane, octane, kerosene, and the like.

The catalyst used in the production method of the present invention is a solid product () obtained by reacting a transition metal compound of Group A or Group A of the periodic table with a solid product () in the presence of an electron donor compound. , furthermore, (group A)
A solid product obtained by reacting two or more transition metal compounds selected from each of the halogen-containing transition metal compounds and (Group B) halogen-free transition metal compounds and an organoaluminum compound. It can be obtained by combining.

The solid product () includes trivalent metal halides and divalent metal hydroxides, oxides, carbonates, double salts containing these, or hydrates of divalent metal compounds (these are combined with divalent metal compounds). (generic name)). In order to carry out this reaction, it is desirable to mix and pulverize in advance for 5 to 100 hours in a ball mill or 1 to 10 hours in a vibration mill to obtain a sufficiently mixed state. The mixing ratio of the trivalent metal halide and the divalent metal compound, expressed as the atomic ratio of the divalent metal to the trivalent metal, is usually in the range of 0.1 to 20, preferably in the range of 1 to 10. The reaction temperature is usually 20-500°C, preferably 50-300°C. A suitable reaction time is 30 minutes to 50 hours, and if the reaction temperature is low, the reaction is allowed to proceed for a long time so that no unreacted trivalent metal remains.

As a specific method for preparing the solid product (2), the following embodiments can be adopted.

(1) Simultaneously mix and react the solid product () with an electron donor compound and a transition metal compound.

(2) Mix the solid product () and the electron donor compound, then add the transition metal compound and then react.

(3) Mix the solid product () and the transition metal compound, then add the electron donor compound and react.

(4) An electron donor compound and a transition metal compound are mixed, and then a solid product () is mixed into this mixture and reacted.

Both methods can be carried out in the presence or absence of a solvent. After the reaction is completed, the mixture is separated by a conventional method, washed repeatedly with a solvent to remove unreacted transition metal compounds and electron donor compounds, and dried to obtain a solid product (2).

The mixing ratio of the solid product (), electron donor compound and transition metal compound in the preparation of the solid product () is 10 to 10,000 g, preferably 20 to 10000 g of the electron donor compound per 100 g of the solid product ().
5000g, the transition metal compound is 1 to 1000g, preferably 10 to 500g, and the electron donor compound is
The transition metal compound is used in an amount of 2 to 2000 g, preferably 5 to 500 g, per 100 g. Mixing is preferably carried out with stirring, and the temperature is suitably between -50°C and +30°C, but most commonly at room temperature (about 20°C). After mixing, the mixture is reacted at 30 to 300°C, preferably 50 to 200°C, for 10 minutes to 30 hours while stirring.

When an electron donor compound and a transition metal compound are mixed and then a solid product () is mixed with this mixture and reacted, the mixture of the electron donor compound and a transition metal compound is a solid product (). Before mixing, warm the mixture to room temperature (approximately 20℃) or above 100℃.
℃ or less, preferably 60℃ or less for 1 minute to
You may leave it for 5 hours.

Solid product () is converted into solid product (),
(Group A) a group a or a halogen-containing transition metal compound; and (group B) a group a or a group a halogen-free transition metal compound.
It is obtained by reacting various transition metal compounds. (A
It is sufficient to use at least one transition metal compound selected from group B) and at least one transition metal compound selected from group B, and therefore two or more transition metal compounds selected from the same group and selected from other groups. It is also within the scope of the present invention to use them together.

The solid product () and a transition metal compound selected from each of (Group A) and (Group B) [hereinafter these may be referred to as (Group A) transition metal compound and (Group B) transition metal compound, respectively; (1) (Group A) transition metal compound and (Group B) transition metal compound Add the solid product () to the mixture and heat.

(2) After mixing the transition metal compound (group A) with the solid product (), the transition metal compound (group B) is added and heated.

(3) A transition metal compound (group A) is heated to react with the solid product (), and then a transition metal compound (group B) is added and heated.

There are various methods such as. Both reaction methods can be carried out with or without the presence of a solvent. After the above reaction is completed, it is separated by a conventional method, washed with a solvent such as an aliphatic hydrocarbon or an aromatic hydrocarbon at room temperature or preferably at 60°C or higher to remove unreacted transition metal compounds, and dried. ,
A solid product () is obtained.

(Group A) (Group B) The ratio of the usage amount of each transition metal compound (if two or more types from one group are used, the total amount) is the number of transition metal atoms contained in the (Group A) transition metal compound. The ratio of (group B) transition metal compound to that (hereinafter simply referred to as transition metal atomic ratio) is 10/1 to 1/10, preferably 5/1 to 1/5. The ratio of the total weight of the solid product () and the transition metal compound is 1 to 100 g of the solid product ().
~1000g is sufficient. Reaction temperature is 30~500℃,
Preferably the temperature is 50 to 300℃, and the reaction time is 10 minutes to
50 hours, preferably 30 minutes to 10 hours. When using a solvent, for 100 g of solid product (),
0 to 1000 ml is sufficient. The transition metal compound is thus supported on the solid product ().

The catalyst of the present invention is obtained by combining the solid product () obtained by the above method with an organoaluminum compound.

Examples of the trivalent metal halide include aluminum trichloride (anhydrous) and iron trichloride (anhydrous).
Examples of divalent metal hydroxides include Mg
Hydroxides like (OH) ₂ , Ca(OH) ₂ , Zn(OH) ₂ , Mn(OH) ₂ , oxides like MgO, CaO, ZnO, MnO _{, MgAl2O4} , _{Mg2SlO 4} , complex oxides containing divalent metals such as _{Mg6MnO8 , MgCO3} ,
Carbonates such as MnCO ₃ , CaCO ₃ , SnCl ₂ .
_2H2O , _MgCl2・_6H2O , _NlCl2・_6H2O ,
Halide hydrates such as _MnCl2・_4H2O , _KMgCl3・_6H2O , hydrates of double salts containing oxides and halides such as 8MgO・_MgCl2・_15H2O ,
Hydrates of double salts containing divalent metal oxides such as 3MgO・2SlO ₂・2H ₂ O, 3MgCO ₃・Mg(OH) ₂・
Hydrates of carbonate and hydroxide double salts such as 3H ₂ O, and 2 such as Mg ₆ Al ₂ (OH) ₁₆ CO ₃ 4H ₂ O
Examples include hydrates of hydroxide carbonates containing valence metals.

As an electron donor compound, ether (RO
-R') Esters (RCO ₂ R'), aldehydes (RCHO), ketones (RCOR'), carboxylic acids (RCO ₂ H), acid anhydrides (R-CO ₂ CO-R'), acid amides (RCONH ₂ ), oxygenated electron donors such as
Nitrogen-containing electron donors such as amines (RnNH _3-o , n=1-3), nitriles (RCN), phosphine (RnPR′ _3-o , n=1-3), phosphorus oxytrichloride (POCl ₃ ) and sulfur-containing electron donors such as thioether (RnSR' _2-o , n=1 to 2) are used. These electron donors can be used alone or in combination of two or more, and polysiloxane can also be used as the electron donor compound.

In each of the above general formulas, R and R' are hydrocarbon groups, more specifically, aliphatic hydrocarbons having 1 to 50 carbon atoms, unsaturated hydrocarbons, monocyclic hydrocarbon groups without substituents, and There are monocyclic hydrocarbon groups, fused polycyclic hydrocarbon groups, etc. Examples of linear aliphatic hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, and octyl, and branched examples include isopropyl, isobutyl, isopentyl, isohexyl, isooctyl, and 2-methylpentyl. , 3-methylpentyl, 5-methylhexyl, etc. Unsaturated hydrocarbon groups include alkenyl groups and alkadienyl groups, which include not only those with terminal unsaturated bonds but also those with internal unsaturated bonds, such as vinyl, allyl, isopropenyl, 1-propenyl, 2-butenyl, 1 , 3-butadienyl, etc. Monocyclic hydrocarbon groups include alicyclic and aromatic hydrocarbon groups, examples without substituents include alicyclic hydrocarbon groups such as cyclopropyl, cyclohexyl, 2-cyclopenten-1-yl, etc. , and a phenyl group. Some examples of substituents include tolyl, xylyl, mesityl, cuyumyl, benzyl, diphenylmethyl, phenethyl, styryl, and the like. Examples of fused polycyclic hydrocarbon groups include naphthyl, anthryl, phenanthryl, 2-indenyl, and 1-pyrenyl.

Polysiloxane has the general formula [-(R ₁ R ₂ SlO-) _o (n
= 3 to 10,000)], where each R represents the same or different type of residue that can be bonded to silicon, and among them, hydrogen, alkyl groups, aryl groups, etc. Those consisting of one type of hydrocarbon residue, halogen, alkoxy group or aryloxy group, fatty acid residue, etc., and those in which two or more of these types are distributed and bonded within the molecule in various ratios are used. . It is desirable that the polysiloxane used be in liquid form, with a suitable viscosity (at 25°C) of 10 to 10,000 centistokes.
Preferably, it is in the range of 10 to 1000 centistokes.

Specific examples of the above electron donor compounds are given below.
Ethers include diethyl ether, dipropyl ether, dibutyl ether, di(isoamyl)
Ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diphenyl ether, tetrahydrofuran, etc. Esters include ethyl acetate, butyl acetate, amyl acetate,
Vinyl butyrate, vinyl acetate, methyl propionate,
Methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, butyl toluate, 2-ethylhexyl toluate, methyl anisate, anisic acid Ethyl, propyl anisate, methyl naphthoate,
Ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, etc. Aldehydes include butyraldehyde, propionaldehyde, benzaldehyde, etc. Ketones include methyl ethyl ketone, diethyl ketone, acetylacetone, acetophenone, benzophenone, etc. Carboxylic acids include Acetic acid, propionic acid, benzoic acid, etc. Acid anhydrides include acetic anhydride, butyric anhydride, benzoic anhydride, etc. Acid amides include formamide, acetamide, benzamide, etc. Amines include methylamine, dimethylamine, trimethylamine, amylamine, aniline , methylaniline, pyridine, etc. Nitriles include acetonitrile, propionitrile, benzonitrile, etc. Phosphines include triethylphosphine, triphenylphosphine, etc. Thioethers include diethyl sulfide, diphenyl sulfide, etc. . In addition, as polysiloxane, octamethyltrisiloxane
Lower polymers such as CH ₃ [Sl(CH ₃ ) ₂ O] ₂ Sl(CH ₃ ) ₃ , octaethylcyclotetrasiloxane [Sl(C ₂ H ₅ ) ₂ O] ₄ , and dimethylpolysiloxane [Sl
(CH ₃ ) ₂ O〕 _o , ethylpolycyclosiloxane [SlH
(C ₂ H ₅ )O] _o , methylethylpolysiloxane [Sl
Alkylsiloxane polymers such as (CH ₃ ) ₍ C _{2 H 5 ) O ]} Arylsiloxane polymers such as (C ₆ H ₅ ) ₂ O] _o , and diphenyl octamethyltetrasiloxane (CH ₃ ) ₃ SlO [Sl(CH ₃ ) (C ₆ H ₅ )
Examples include alkylarylsiloxane polymers such as O] ₂ Sl(CH ₃ ) ₃ and methylphenylpolysiloxane [Sl(CH ₃ )(C ₆ H ₅ )O] _o . Other examples include alkyl hydrogen siloxane polymers, haloalkyl siloxanes, haloaryl siloxane polymers, and polysiloxanes in which each R is an alkoxy or aryloxy group or a fatty acid residue. Also,
These various polysiloxanes can also be used in combination.

Examples of transition metal compounds include titanium, vanadium halides, oxyhalides, alcoholates, alkoxyhalides, and acetoxyhalides, such as titanium tetrachloride, titanium tetrabromide, tetraethoxytitanium, tetrabutoxytitanium, monochlorobutoxytane, and dichloro. Examples include dibutoxytitanium, trichloromonoethoxytitanium, vanadium tetrachloride, vanadium oxytrichloride, and the like.

(Group A) halogen-containing transition metal compounds include compounds such as titanium, vanadium halides, oxyhalides, alkoxyhalides, and acetoxyhalides, such as titanium tetrachloride, titanium tetrabromide, trichlormonoisopropocytitanium, and dichlordiisopropylene. Examples include poxytitanium, monochlorotriisopropoxytitanium, trichlormonobutoxytitanium, dichlorodibutoxytitanium, monochlorotributoxytitanium, vanadium tetrachloride, and vanadium oxytrichloride.

(Group B) halogen-free transition metal compounds include alkoxides of titanium and vanadium, such as tetramethyl orthotitanate (tetramethoxytitanium), tetraethyl orthotitanate (tetraethoxytitanium), and tetraisopropyl orthotitanate ( tetraisopropoxy titanium),
Tetra-n-butyl orthotitanate (tetra-n-
tetraalkyl orthotitanate (tetraalkoxytitanium) such as butoxytitanium), vanadyl triethylate (VO(OC ₂ H ₅ ) ₃ ), vanadyl triisopropylate (VO(OCH(CH ₃ ) ₂ ) ₃ ), vanadyl trin -There are vanadyl trialcholates such as butyrate (VO(OC ₄ H ₉ ) ₃ ). As the compound of (Group B), a polytitanate ester represented by the general formula RO-[Tl(OR) ₂ -O-] _nR can be used. (In the formula, m is an integer of 2 or more, preferably 2
~10, R represents an alkyl group, an aryl group, or an aralkyl group, and all R's do not need to be the same type of group. The number of carbon atoms in R is preferably 1 to 10, but
It is not particularly limited, and a part of the alkoxy group may be a hydroxyl group. )in particular,
Methyl polytitanate, ethyl polytitanate, isopropyl polytitanate, n-propyl polytitanate, n-butyl polytitanate, n- polytitanate
Hexyl etc.

Examples of organic aluminum compounds include trialkylaluminum such as triethylaluminum, triisobutylaluminum, and trihexylaluminum, dialkylaluminum monochloride such as diethylaluminum monochloride, and ethylaluminum sesquichloride, as well as monoethoxydiethylaluminum, diethoxymonochloride, etc. There are alkoxyalkylaluminums such as ethylaluminum.

In the catalyst preparation of the present invention, solvents used during the reaction and for washing after the reaction include aliphatic hydrocarbons such as hexane, heptane, octane, nonane, and decane, and aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene. Examples include hydrocarbons, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene, and halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloroethane, trichlorethylene, tetrachlorethylene, and carbon tetrabromide. .

A feature of the present invention is that the special polymerization catalyst shown in the present invention is used in a continuous multi-stage polymerization method in which a low-molecular-weight polymer is produced in the first stage polymerization system, and then a high-molecular-weight polymer is produced in the second stage polymerization system. This made it possible to perform low-temperature polymerization (slurry polymerization) below 120°C. Therefore, compared to known continuous high-temperature melt polymerization, this method has the advantage of excellent economic efficiency in that less solvent is used during polymerization, and it also has the advantage that the polymer can be obtained in powder form. In addition, in the polymerization of the present invention, there is no or very little polymer adhesion to the walls of the polymerization vessel.
It is characterized by the ability to perform stable multi-stage polymerization over a long period of time. The catalyst used in the present invention is different from known catalysts and has extremely high polymerization activity, making it possible to eliminate the step of removing the residual catalyst in the polymer, that is, the deashing step after the reaction is completed.

Another feature of the present invention is that the resulting polyethylene has a much broader molecular weight distribution than conventional continuous high temperature melt polymerizations. Therefore, the flow characteristics during molding are good, the resin pressure during molding is low, high-speed molding is possible, and the appearance of the molded product is good because melt fracture does not occur. For film production,
It has appropriate strength and opacity, has no visible fish eyes, has a smooth film surface, and has stable moldability over a long period of time. In addition, the bulk specific gravity of the polyethylene powder obtained by the present invention is 0.35 to 0.43, and the shape of the powder particles is good, so the production efficiency per unit volume of the polymerization vessel and per hour is high, and the piping of the polymer powder is Fewer problems occur during transportation,
It also has the characteristic of being easy to granulate powder.

Hereinafter, the features of the present invention will be specifically explained with reference to Examples. In the examples, the melt index is
In accordance with ASTM D-1238(E). _W / _N ( _W is the weight average molecular weight, _N is the number average molecular weight) was determined by gel permeation chromatography using GPC-200 manufactured by Waters.

Example 1 (1) Production of transition metal catalyst component 76 kg of magnesium hydroxide and 90 kg of aluminum chloride (anhydrous) were mixed in advance in a vibration mill for 5 hours, pulverized, and then reacted at 150° C. for 5 hours.
After that, it is cooled and pulverized to produce a solid product ().
I got it.

173 kg of titanium tetrachloride and 100 kg of linear dimethylpolysiloxane (viscosity 100 centistokes) were added to 150 kg of toluene and mixed. Next, 100 kg of the above solid product (2) was added and reacted at 110°C for 2 hours. After the reaction is complete, evaporate according to the usual method,
The solid product is washed with hexane until unreacted titanium tetrachloride and unreacted polysiloxane are no longer detected in the liquid, and after drying under reduced pressure, the solid product ()
I got it.

87 kg of titanium tetrachloride and 65 kg of tetraisopropyl orthotitanate were added and mixed in 200 g of toluene, and then 100 kg of the above solid product (2) was added and reacted at 90°C for 1 hour and then at 120°C for 2 hours. After the reaction is completed, the solution is washed repeatedly with hexane until no titanium compound is detected in the solution, followed by drying under reduced pressure to obtain a solid product ().
I got it. The titanium atoms in 1 kg of solid product () are
It was 2.2 mol.

(2) Multistage continuous polymerization of ethylene In the first stage polymerization vessel with an internal volume of 10, the solid product () was converted into titanium atoms per hour.
0.088mmol triethylaluminum per hour
0.4 mmol and hexane were fed at a rate of 3 per hour, and at 80°C, butene-1 was added to 5% (volume % ) containing ethylene at 360N per hour and hydrogen in the polymerizer gas phase where the molar ratio of ethylene (including butene) to hydrogen is 1:1.6.
The first stage polymerization was carried out continuously at a total pressure of 40 Kg/cm ² (gauge pressure) while supplying the polymer so as to achieve the following.

After the first stage polymerization was completed, the polymer suspended in the solvent was introduced into a degassing tank maintained at an internal pressure of 2 kg/cm ² (gauge pressure) to separate most of the hydrogen dissolved in hexane. The separated hydrogen was recycled and reused so that the ratio of ethylene to hydrogen in the gas phase of the first stage polymerization vessel could be maintained at a predetermined ratio.

The polymer slurry leaving the degassing tank has an internal volume of 10
The entire amount was introduced into the second stage polymerization vessel, and the contents were heated to 75°C while draining the contents of the polymerization vessel so that the liquid level in the polymerization vessel was maintained at 80% without adding hydrogen or the chemical medium.
Ethylene was supplied at a rate of 340 N per hour, and the second stage polymerization was carried out continuously at a total pressure of 40 Kg/cm ² (gauge pressure). The molar ratio of ethylene to hydrogen in the gas phase of the second stage polymerizer was 1:0.07.

The above multi-stage polymerization was carried out continuously for 120 hours, but
The operation is extremely stable, and after drying without deashing, the polymer powder 102 has a melt index of 0.05, a bulk specific gravity of 0.38, a density of 0.950, and a molecular weight distribution of M _w /M _N of 29.
Got Kg. When a film was manufactured using this polyethylene, it was found that the film formability was stable, the film had appropriate strength and opacity, no visible fissures were observed, and the surface condition was good, which is satisfactory. Ta.

Example 2 (1) Production of transition metal catalyst component 75 g of magnesium oxide and 80 g of aluminum chloride (anhydrous) were mixed in a ball mill for 24 hours, pulverized, heated at 200°C for 3 hours, cooled and pulverized,
A solid product () was obtained.

150 g of solid product () in 200 ml of heptane,
Chain methylethyl polysiloxane 80g (viscosity 500
centistokes) and 130 g of titanium tetrachloride were added at the same time, mixed, and reacted at 80° C. for 3 hours.
After that, washing with hexane was performed to obtain a solid product (2).

In 400 ml of toluene, 100 g of the solid product () and 87 g of titanium tetrachloride were added and mixed, then 47 g of isopropyl polytitanate (pentamer) was added,
The reaction was carried out at 110°C for 3 hours. Thereafter, washing was performed in the same manner as in Example 1 to obtain a solid product (2). The amount of titanium atoms in 1 g of the solid product ( ) was 2.1 mmol.

(2) Multi-stage continuous polymerization of ethylene. Add 210N of ethylene per hour to the first stage polymerization vessel.
, hydrogen was supplied to the second stage polymerization vessel such that the molar ratio of ethylene to hydrogen in the gas phase of the polymerization vessel was 1:1.3.
Multistage continuous polymerization of ethylene was carried out in the same manner as in Example 1, except that 200 N of ethylene was supplied per hour at 70°C, and the molar ratio of ethylene to hydrogen in the gas phase of the polymerization reactor was adjusted to 1:0.17. do the
After 150 hours of continuous operation, 127 kg of polymer powder was obtained.
This polyethylene has a melt index of 0.30,
The bulk specific gravity is 0.36, the density is 0.954M _w / M _N 26, and when the bottle is molded by blow molding, the resin pressure during molding is low and high speed molding is possible, the surface of the molded product is good, and the weight of the molded product is low. Also, the lack of uneven thickness was also satisfactory.

Example 3 70 g of hydrotalcite and 80 g of aluminum chloride (anhydrous) were mixed, pulverized, and reacted simultaneously while heating at 170° C. for 3 hours in a vibrating mill to obtain a solid product ().

Mix 100 g of titanium tetrachloride and 100 g of solid product () in 200 ml of toluene, followed by
130 g of butyl ether was added and reacted at 100° C. for 3 hours, and after washing with hexane, a solid product () was obtained.

In 400 ml of xylene, 100 g of the solid product (2) and 114 g of titanium tetrachloride were added and mixed, and the mixture was reacted at 80°C for 3 hours. After that, 58 g of tetra-n-butyl orthotitanate was added and reacted at 130°C for 2 hours. Thereafter, washing was performed in the same manner as in Example 1 to obtain a solid product (2). Titanium atoms in 1g of solid product () are
It was 1.9 mmol.

Using this solid product (2), multistage continuous polymerization of ethylene was carried out in the same manner as in Example 1 (2), and 102 kg
A polymer powder was obtained. Melt index 0.03,
M _w /M _N was 27, and a satisfactory film could be produced in the same manner as in Example 1.

Example 4 90 kg of aluminum chloride (anhydrous) and 110 kg of Magsia cement were mixed in a ball mill for 48 hours and ground.
After heating at 250°C for 2 hours, the mixture was cooled and ground to obtain a solid product ().

100 kg of solid product () and 60 kg of n-butyl acetate were mixed in xylene 200, followed by adding 100 kg of titanium tetrachloride and reacting at 120° C. for 2 hours. After washing with hexane, solid product () was obtained.

In 400 g of toluene, 100 kg of the solid product () and 84 kg of n-butyl polytitanate were added and mixed, and then 174 kg of titanium tetrachloride was added and reacted at 120° C. for 2 hours. After that, wash in the same manner as in Example 1,
A solid product () was obtained. Solid product () 1Kg
The amount of titanium atoms in it was 1.8 mol.

Using this solid product (2), multistage continuous polymerization of ethylene was carried out in the same manner as in Example 2 (2), and 127 kg
A polymer powder was obtained. This polyethylene had a melt index of 0.35 and M _w /M _N of 24, and a satisfactory bottle could be produced in the same manner as in Example 2.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the catalyst according to the production method of the present invention.

Claims (1)

[Scope of Claims] 1. A method for producing polyethylene by continuous multistage polymerization in the presence of a solvent and hydrogen using a catalyst obtained by combining a transition metal compound catalyst component and an organometallic compound catalyst component. (i) Electron-donating to a solid product obtained by reacting an aluminum halide with a magnesium hydroxide, oxide, carbonate, a double salt containing these, or a hydrate of a magnesium compound. A titanium compound is reacted in the presence of a titanium compound, and the thus obtained solid product () further contains (group A) a halogen-containing titanium compound (hereinafter referred to as a halogen-containing titanium compound) and (B group) a halogen-containing titanium compound. A solid product obtained by reacting at least two titanium compounds selected from each group of halogen-free titanium compounds (hereinafter referred to as halogen-free titanium compounds) and an organic aluminum compound. In the presence of a catalyst, in a saturated hydrocarbon solvent, in the presence of a gas phase at the top of the polymerization vessel, the polymerization temperature is 50°C or higher at 120°C.
℃ or less and a polymerization pressure of 5 to 70 kg/cm ² , hydrogen is supplied so that the molar ratio of ethylene to hydrogen in the gas phase of the polymerizer is 1:0.1 to 3.0, and 30% of the total ethylene supply amount is The first stage polymerization is carried out by supplying ~90% ethylene; (ii) After the first stage, the polymer suspended in the solvent is heated at a pressure of 1 to 30 Kg/cm ² below the first stage polymerization pressure. (iii) introducing the suspended polymer into a low pressure zone, separating at least a portion of the hydrogen dissolved in the solvent, and returning at least a portion of the separated hydrogen to the first stage polymerization system; , hydrogen is supplied so that the molar ratio of ethylene to hydrogen in ^the gas phase of the polymerization vessel is 1:0.001 to 0.5 under the conditions of a polymerization temperature of 30°C to 100°C and a polymerization pressure of 5 to 70 kg/cm 2 . , supplying 10 to 70% of the total ethylene amount,
A method for producing polyethylene by continuous multi-stage polymerization, characterized by carrying out a second stage polymerization. 2. Polyethylene according to claim 1, characterized in that a small amount of α-olefin is supplied to the first stage polymerization system and/or the second stage polymerization system to produce a copolymer with ethylene. Production method. 3. The manufacturing method according to claim 1, wherein the electron donor compound is an ether, ester, aldehyde, ketone, acid anhydride, or polysiloxane. 4 Solid product () is 100g of solid product ()
The manufacturing method according to claim 1, wherein the amount of the electron donor compound is 20 to 1000 g and the titanium compound is 10 to 500 g, and the amount of the titanium compound is 30 to 500 g per 100 g of the electron donor compound. 5 The ratio of the number of titanium atoms contained in each of the halogen-containing titanium compound (Group A) and the halogen-free titanium compound (Group B) in the solid product () is 10/
1 to 1/10, and the total amount of both compounds is 1 to 1000 g per 100 g of solid product ().
The manufacturing method according to claim 1, obtained by reacting at a reaction temperature of 30 to 500°C.