JPH04331206A - Production of polyethylene - Google Patents

Abstract

PURPOSE:To obtain a discoloration-free high-molecular weight polymer by (co)polymerizing ethylene above the melting point of the polymer in the presence of a highly active catalyst system comprising a solid transition metal catalyst component of a specified composition and an organoaluminum compound. CONSTITUTION:A solid transition metal catalyst component is produced by reacting a magnesium compound selected between an organic oxygen compound of magnesium and a magnesium halide and/or metallic magnesium and a hydroxylated organic compound with an organic oxygen compound of titanium or a titanium halide, an oxygen compound of zirconium or a zirconium halide, a polysilioxane or a silane and a halogenated organoalumium compound. Polyethylene is produced by (co)polymerizing ethylene above the melting point of the polymer by using a catalyst system comprising the above catalyst component and an organoaluminum compound of the formula (wherein R<1> and R<2> are each 1-20C alkyl; X is halogen; 0<j<=3; 0<=k<=2; and 0<j+k<=3).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyethylene using a novel catalyst. More specifically, the present invention relates to a method for producing polyethylene, which comprises polymerizing ethylene or copolymerizing ethylene and α-olefin using a novel catalyst with high catalytic activity at a temperature equal to or higher than the melting point of polyethylene.

Generally, ethylene polymers and ethylene/α-olefin copolymers polymerized by Ziegler type catalysts have a wide range of density, usually from 0.880 to 0.975 g/cm3, and are used in a wide range of applications such as films and molded products. It is used in

0003

[Prior Art] As a method for polymerizing ethylene using a Ziegler type catalyst at a temperature higher than the melting point of polyethylene,
Solution polymerization methods and high temperature/high pressure polymerization methods are known. Generally, in a solution polymerization method carried out in an inert solvent, the polymerization temperature is preferably higher from the viewpoint of reducing the viscosity of the solution and facilitating the removal of polymerization heat. Similarly, in the high-temperature, high-pressure method, the greater the temperature difference between the polymerization temperature and the feedstock, the better the ethylene conversion rate, and therefore the higher the polymerization temperature, the greater the economic benefit. On the other hand, in polymerization in these high temperature ranges, catalyst activity and activity persistence generally decrease as the polymerization temperature increases. When the catalyst activity is low, the amount of catalyst residue in the polymer increases, which tends to cause corrosion of process equipment, coloring of the polymer, and gel formation. Conventionally, many proposals have been made as catalysts that can be used in high-temperature polymerization. For example, a catalyst system in which a titanium halide is combined with an alkyl aluminum compound containing a halogen group and an organomagnesium compound was proposed in Japanese Patent Publication No. 1372/1983. However, it cannot be said that the catalytic activity of this catalyst system is satisfactory, and further improvement of the catalytic activity is desired.

[0004] In addition to simply high activity, it is also important to arbitrarily control the molecular weight of the produced polymer in response to diversification of quality. In particular, polymers with a high molecular weight are desired to have a high molecular weight because they are suitable for blow molding and film molding. However, when conventional Ziegler-type catalysts are used for high-temperature polymerization, they have the disadvantage that the molecular weight of the resulting polymer decreases. For this reason, it has been difficult to arbitrarily control the molecular weight of the produced polymer from a high molecular weight to a low molecular weight.

[0005] The inventors of the present invention have conducted intensive studies on a method for producing highly active and high molecular weight polyethylene even at high temperatures above the melting point of the polymer, and have finally completed the present invention.

[0006]

OBJECTS OF THE INVENTION It is an object of the present invention to provide polyethylene with high activity and long-lasting activity in a temperature range higher than the melting point of polyethylene, that is, in solution polymerization or high-temperature and high-pressure polymerization, without requiring a catalyst removal step. Able to produce polyethylene with excellent comonomer reactivity and high molecular weight.
The object of the present invention is to provide a catalyst system.

[0007]

[Means for Solving the Problems] The gist of the present invention is that in the presence of a catalyst consisting of a transition metal compound and an organometallic compound,
A transition metal solid catalyst obtained by reacting the following compounds (i) to (v) when polymerizing ethylene or copolymerizing ethylene and at least one α-olefin at a reaction temperature higher than the melting point of the polymer. Ingredient (A) Ingredient (i)
At least one magnesium compound selected from an oxygen-containing organic compound of magnesium and a halogen-containing compound, and/or metallic magnesium, and an organic hydroxide compound (ii) An oxygen-containing organic compound of titanium and a halogen-containing compound , at least one titanium compound, (iii) at least one zirconium compound selected from zirconium oxygen-containing organic compounds and halogen-containing compounds, and (iv) polysiloxane, and silanes.
at least one silicon compound, and (v) at least one halogenated organoaluminium compound, and (B) component having the general formula AlR1j(OR2)kX3-k (wherein R1 and R2 are 1 to 20 carbon atoms X represents a halogen atom, j represents 0<j≦3, k represents 0≦k≦2, and represents a number such that 0<j+k≦3) Alternatively, there is provided a method for producing polyethylene, characterized in that a catalyst system comprising at least one organoaluminum compound from the group represented by aluminoxane is used. [Function] The above-mentioned (
Examples of the metal magnesium and the hydroxide organic compound and the oxygen-containing organic compound of magnesium in i) include the following.

First, when using magnesium metal and an organic hydroxide compound, magnesium metal can be used in various forms, such as powder, particles, foil, or ribbon. Suitable compounds include alcohols, organic silanols, and phenols.

As alcohols, linear or branched aliphatic alcohols, cycloaliphatic alcohols or aromatic alcohols having 1 to 18 carbon atoms can be used. Examples include methanol, ethanol, n-butanol, n-octanol, n-stearyl alcohol, cyclopentanol, ethylene glycol, and the like.

[0010] Furthermore, the organic silanol has at least one hydroxyl group, and the organic group is 1 to 12
alkyl groups, cycloalkyl groups, arylalkyl groups having 1 to 6 carbon atoms, preferably 1 to 6 carbon atoms;
selected from aryl groups and alkylaryl groups. For example, we can give the following example. trimethylsilanol,
Triethylsilanol, triphenylsilanol, t-
butyldimethylsilanol, etc.

[0011] Furthermore, as phenols, phenol,
Examples include cresol, xylenol, and hydroquinone.

In addition, when using metallic magnesium to obtain the solid component described in the present invention, for the purpose of promoting the reaction, a substance that reacts with metallic magnesium or purifies an addition compound, such as iodine, is added. It is preferable to add one or more polar substances such as mercuric chloride, alkyl halides, organic acid esters, and organic acids.

Compounds belonging to the oxygen-containing organic compounds of magnesium include magnesium alkoxides such as methylate, ethylate, isopropylate, decalate, and cyclohexanolate, magnesium alkyl alkoxides such as ethyl ethylate, magnesium hydroalkoxides such as Hydroxymethylates, magnesium phenoxides such as phenate, naphthenate, phenanthrenate and cresolate, magnesium carboxylates such as acetate, stearate, benzoate, phenylacetate, adipate, sebacate, phthalate, acrylate and oleate, oxygen-containing organomagnesiums Compounds that further contain nitrogen, i.e. magnesium-
Compounds having oxygen-nitrogen-organic radical bonds in this order, such as oximates, especially butyloximate, dimethylglyoximate and cyclohexyloximate, hydroxamates, hydroxylamine salts, especially N-nitroso-N-phenyl-hydroxyl Amine derivatives, magnesium chelates, that is, oxygen-containing organic compounds in which magnesium has at least one magnesium-oxygen-organic group bond in this order and further has at least one ligand bond to form a magnesium-containing heterocycle. , for example enolates, especially acetylacetonates, e.g. complexes obtained from phenol derivatives with an electron-donating group in the position ortho or meta to the hydroxyl group, especially 8-hydroxyquinolinate, as well as magnesium silanolates, i.e. magnesium- oxygen-silicon-
Examples include compounds containing hydrocarbon group bonds in this order, such as triphenylsilanolate. Of course, this series of oxygen-containing organic compounds also includes the following compounds: That is, compounds containing several different organic groups such as magnesium methoxyethylate, complex alkoxides of magnesium with other metals and phenoxides, such as Mg[Al(OC2H5)4]2 and Mg3[Al(OC2H5)6 ]2 is also included. These oxygen-containing organomagnesium compounds may be used alone or as a mixture of two or more.

Examples of the halogen-containing magnesium compound include anhydrous or hydrated magnesium dihydrides, MgCl2, MgCl2.6H2O, MgCl2.4
H2O and MgCl2.2H2O, compounds containing inorganic groups, such as hydroxy groups, which are bonded to magnesium via oxygen in addition to the magnesium-halogen bond;
For example, it contains Mg(OH)Cl and Mg(OH)Br, a hydrolysis product of magnesium halides (preferably chloride) that leaves a magnesium-halogen bond, a halogen-containing compound of magnesium, and an oxygen-containing compound. , mixed composition [Typical examples of these compositions include basic magnesium halides (preferably chlorides), such as MgCl2.MgO.H2O, MgCl2.MgO.H2O,
gCl2.3MgO.7H2O and MgBr2.3M
gO・6H2O, etc.). These halogen-containing magnesium compounds may be used alone or as a mixture of two or more.

As the titanium oxygen-containing organic compound (ii), a compound represented by the general formula [TiOa(OR3)bXc]m is used. However, in the general formula, R3 represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, such as a straight chain or branched alkyl group, cycloalkyl group, arylalkyl group, aryl group, alkylaryl group, represents a halogen atom.

[0016] a, b and c are a≧0, b>0, 4>
c≧0, which is a number compatible with the valence of titanium, and m
is an integer. Above all, a is 0≦a≦1 and m is 1≦
It is desirable to use an oxygen-containing organic compound in which m≦6.

[0017] As a specific example, Ti(OC2H5)
4, Ti(O-n-C3H7)4, Ti(O-i-C3
H7)4, Ti(O-n-C4H9)4, Ti2O(O
-i-C3H7)6, Ti(OC2H5)2Cl2, T
i(OC2H5)3Cl, etc. The use of oxygen-containing organic compounds containing several different hydrocarbon groups is also within the scope of the invention. It is also within the scope of the present invention to use these titanium oxygen-containing compounds alone or in a mixture of two or more.

As the zirconium oxygen-containing compound (iii), a compound represented by the general formula [ZrOd(OR4)e]n is used. However, in the general formula, R4 represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, such as a linear or branched alkyl group, cycloalkyl group, aryl group, or alkylaryl group, and d and e is a number compatible with the valence of zirconium such that d≧0 and e>0, and n is an integer. In particular, it is desirable to use an oxygen-containing compound in which d satisfies 0≦d≦1 and n satisfies 1≦n≦6.

A specific example is Zr(O-n-C4H9)
4, Zr (OC6H5) 4, Zr (OCH3) [OC(
CH3)3]3, Zr[OZr(OC2H5)3]4, etc. It also contains several different hydrocarbon groups,
The use of oxygen-containing organic compounds is also within the scope of this invention. These zirconium oxygen-containing organic compounds may be used alone or as a mixture of two or more.

Further, as the halogen-containing compound of zirconium, halides such as ZrCl4, ZrF4,
Oxyhalides, such as ZrOF2, ZrOCl2,
and halogenoalkoxides, such as Zr(O-n
-C4H9)Cl3, Zr(O-n-C4H9)2Cl
2, Zr(OC2H4)3Cl, Zr(O-i-C3H
7) Examples include Cl3, Zr(O-n-C3H7)Cl3, and the like. Also within the scope of this invention are zirconium halogen-containing compounds containing several different organic groups. These may be used alone or as a mixture of two or more.

The following polysiloxanes and silanes are used as the silicon compound as the reactant (iv).

The polysiloxane has the general formula

002
3]

[Formula 1] (wherein R5 and R6 are hydrocarbon groups such as alkyl groups and aryl groups having 1 to 12 carbon atoms, hydrogen, halogen, alkoxy groups having 1 to 12 carbon atoms, allyloxy groups, fatty acid residues, etc.) Represents an atom or residue capable of bonding to silicon, R
5 and R6 may be the same or different; n usually represents an integer from 2 to 10,000), and the molecule contains one or more repeating units in various ratios and distributions. A siloxane polymer having a chain, cyclic or three-dimensional structure (provided that all R5 and R6 are
(excluding hydrogen or halogen).

Specifically, examples of chain polysiloxane include hexamethyldisiloxane, octamethyltrisiloxane, dimethylpolysiloxane, diethylpolysiloxane, methylethylpolysiloxane, methylhydropolysiloxane, ethylhydropolysiloxane, butyl Hydropolysiloxane, hexaphenyldisiloxane,
Octaphenyltrisiloxane, diphenylpolysiloxane, phenylhydropolysiloxane, methylphenylpolysiloxane, 1,5-dichlorohexamethyltrisiloxane, 1,7-dichlorooctamethyltetrasiloxane, dimethoxypolysiloxane, diethoxypolysiloxane, diphenoxy Examples of cyclic polysiloxanes such as polysiloxane include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, 2,4,6-trimethylcyclotrisiloxane, 2,4,6,8-tetramethyl Examples include cyclotetrasiloxane, triphenyltrimethylcyclotrisiloxane, tetraphenyltetramethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, and octaphenylcyclotetrasiloxane.

Examples of polysiloxanes having a three-dimensional structure include those obtained by heating the above-mentioned chain or cyclic polysiloxanes to have a crosslinked structure.

These polysiloxanes are desirably liquid in handling, and have a viscosity of 1 to 100 at 25°C.
00 centistokes, preferably in the range of 1 to 1000 centistokes. However, it is not necessary to limit it to a liquid form, and a solid substance generally referred to as silicone grease may also be used.

The silanes have the general formula HpSiqR7r.
Xs (wherein R7 represents a hydrocarbon group such as an alkyl group having 1 to 12 carbon atoms or an aryl group, a group capable of bonding to silicon such as an alkoxy group having 1 to 12 carbon atoms, an allyloxy group, or a fatty acid residue, Each R7 may be different or the same, X represents a halogen different or the same, and p
is 0 or more and less than 4, r and s are integers of 0 or more, q is a natural number, and p+r+s=2q+2 or p+r+s=2
Examples include silicon compounds represented by q).

Specifically, silahydrocarbons such as trimethylphenylsilane and allyltrimethylsilane, linear and cyclic organic silanes such as hexamethyldisilane and octaphenylcyclotetrasilane, methylsilane,
Organic silanes such as dimethylsilane and trimethylsilane,
Silicon halides such as silicon tetrachloride and silicon tetrabromide,
dimethyldichlorosilane, diethyldichlorosilane, n
- Alkyl and aryl halogenosilanes such as butyltrichlorosilane, diphenyldichlorosilane, triethylfluorosilane, dimethyldibromosilane, trimethylmethoxysilane, dimethyldiethoxysilane, tetramethoxysilane, diphenyldiethoxysilane, tetramethyldiethoxysilane, dimethyltetra Alkoxysilanes such as ethoxydisilane, haloalkoxy and phenoxysilanes such as dichlorodiethoxysilane, dichlorodiphenylsilane, tribromoethoxysilane,
Examples include silane compounds containing fatty acid residues such as trimethylacetoxysilane, diethyldiacetoxysilane, and ethyltriacetoxysilane.

The above silicon compounds may be used alone, or two or more of them may be mixed or reacted.

As the halogenated organic aluminum compound (v), those represented by the general formula AlR8tX3-t are used. However, in the general formula, R8 is 1
~20 hydrocarbon groups, X represents halogen, F, Cl
, Br, or I. t is a number satisfying 1≦t<3. Preferably R8 is selected from straight chain or branched alkyl, cycloalkyl, arylalkyl, aryl, alkylaryl groups.

The above halogenated organoaluminum compounds can be used alone or as a mixture of two or more. Specific examples of halogenated organoaluminum compounds include trimethylaluminum, triethylaluminum, tri-i-propylaluminum, tri-i-
-butylaluminum, ethylaluminum dichloride, n-propylaluminum dichloride, n-butylaluminum dichloride, i-butylaluminum dichloride, sesquiethylaluminum chloride,
sesqui-i-butylaluminum chloride, sesqui-i-butylaluminum chloride
i-propylaluminum chloride, sesqui-n-propylaluminum chloride, diethylaluminum chloride, di-i-propylaluminum chloride, di-n-propylaluminum chloride, di-i-
Examples include butylaluminum chloride, diethylaluminum bromide, diethylaluminum iodide, and the like.

[0032] These reactions are preferably carried out in a liquid medium. This can therefore be carried out in the presence of an inert organic solvent, especially if these reactants themselves are not liquid under the operating conditions or if the amount of liquid reactants is insufficient. As the inert organic solvent, any solvent commonly used in the art can be used, including aliphatic, alicyclic, or aromatic hydrocarbons, their halogen derivatives, or mixtures thereof, such as isobutane, Hexane, heptane, cyclohexane, benzene, toluene, xylene, monochlorobenzene and the like are preferably used.

Reactants (i) and (ii) used in the present invention
(iii) (iv) There is no particular restriction on the amount of (v) used, but the ratio of magnesium atom (i) to titanium atom (ii) is 1:0.01 to 1:20, preferably 1: 0.1
It is preferable to select the amount to be used so that the ratio is ~1:5. The ratio of magnesium atoms to zirconium atoms (iii) is 1
:0.01~1:20, preferably 1:0.05~1:
It is preferable to select the amount to be used so that the amount is 5. The ratio of magnesium atoms to silicon atoms in the silicon compound (iv) is 1:0.01 to 1:20, preferably 1:0.1 to
Preferably, the amount of reactant is chosen to be in the range 1:5. The ratio of magnesium atoms to aluminum atoms in the halogenated organic aluminum compound (v) is 1:0.0
It is preferred to select the amount of reactant so that it is in the range of 1 to 1:100, preferably 1:0.02 to 1:20. In particular, a range of 1:0.05 to 1:1 is suitable. Outside these ranges, the polymerization activity will be low.

The reaction conditions for obtaining a homogeneous solution using reactants (i) and (ii) are -50 to 300°C, preferably 0 to 300°C.
It is carried out at a temperature in the range of 200 DEG C. for 0.5 to 50 hours, preferably 1 to 6 hours, under normal or elevated pressure in an inert gas atmosphere.

Furthermore, reactant (iv) and reactant (v)
-50 to 200°C, preferably -30°C during the reaction.
The reaction is carried out at a temperature in the range from 100 DEG C. to 100 DEG C. for 0.2 to 50 hours, preferably 0.5 to 5 hours, in an inert gas atmosphere or under pressure.

The solid component (A) thus obtained is a particle insoluble in the solvent used as a diluent, and residual unreacted substances and by-products are removed by filtration or decanting, and then the solid component (A) is dissolved in an inert solvent. After washing several times, you can get it. Catalyst component (A) may be used as it is, but generally, residual unreacted substances and by-products are removed by filtration or decanting, and after washing with an inert solvent several times, it is inactivated. Use by suspending in a solvent. It is also possible to use a product obtained by isolating it after washing and heating it under normal pressure or reduced pressure to remove the solvent.

Catalyst component (B) used in the present invention
As, the general formula AlR1j(OR2)kX3-k (wherein R1 and R2 represent an alkyl group having 1 to 20 carbon atoms, X represents a halogen atom, and j and k are 0
<j≦3, preferably 0<j<3, 0≦k≦2, 0<j
+k≦3) or aluminoxane, at least one type of organoaluminum compound can be mentioned. Specific examples of the organic aluminum compound represented by the above general formula AlR1j(OR2)kX3-k include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, etc. trialkylaluminum, diethylaluminum monochloride, diisopropylaluminium monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum monobromide, diisopropylaluminum monobromide, alkylaluminum halides, dimethylaluminum ethoxide, diethyl Alkylaluminum alkoxides such as aluminum ethoxide, diethylaluminum propoxide, diethylaluminum butoxide, diethylaluminum phenoxide, and ethylaluminum diethoxide can be mentioned.

As the aluminoxane, it is also possible to use aluminoxane compounds in which two or more aluminum atoms are bonded via oxygen atoms or nitrogen atoms, such as multimers such as tetramethylaluminoxane and polymethylaluminoxane.

These organoaluminum compounds may be used alone or as a mixture of two or more. Although it is of course possible to use them alone, it is preferable to use them as a mixture of two or more types, which brings about further effects in improving polymerization activity and copolymerizability.

The amount of component (B) used is in the range of 1 to 1000 mol, preferably 1 to 100 mol, per gram atom of titanium contained in catalyst component (A).

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

Polymerization of ethylene occurs at temperatures above the melting point of the resulting polymer;
The polymerization is preferably carried out at a temperature in the range of 130 to 300°C, and an inert solvent or the monomer itself is used as the polymerization medium.

In solution polymerization using an inert solvent, aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, undecane, dodecane and mixtures thereof, aromatic hydrocarbons such as benzene and toluene, Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are used. Polymerization pressure is 1-200k
g/cm2, preferably from 10 to 50 kg/cm2, and the residence time ranges from 1 minute to 6 hours, preferably from 4 minutes to 3 hours.

In high-temperature, high-pressure polymerization in which the monomer itself is used as the polymerization medium, a high-pressure radical polymerization apparatus for ethylene can generally be used, and the polymerization pressure is 200 to 25%.
00kg/cm2, preferably 400-1500kg/
cm2, residence time 5-600 seconds, preferably 10-15
This is done within a range of 0 seconds.

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

[0046]

Effects of the Invention The first effect of the present invention is that a polymer can be obtained which has extremely high polymerization activity per transition metal and per solid catalyst and does not require a deashing step for the purpose of removing the catalyst. Because it is highly active, there is no need to worry about coloring or odor of the product, and there is no need to generate polymers, making it extremely economical.

The second effect of the present invention is that the catalyst has excellent thermal stability. Therefore, it has a relatively long active life even at high temperatures.

The third effect of the present invention is that the molecular weight of the obtained copolymer can be increased. Therefore, for blow molding,
A polymer suitable for film molding can be obtained, and the surface properties of the molded product can also be improved.

The fourth effect of the present invention is that copolymerizability with other α-olefins (comonomers) is good;
The polymerization conversion rate of comonomer is high compared to other catalyst systems. (A small amount of copolymerized α-olefin is required.)

[0050]

[Examples] The present invention will be illustrated by examples below, but the present invention is not limited to these examples in any way unless the gist of the invention is exceeded.

In the examples, MI stands for melt index, which was measured based on JIS K-6760 under the conditions of 190° C. and a load of 2.16 kg. Density was measured according to JISK-6760.

Polymerization activity is determined by the amount of polymer produced (kg) per 1 g of solid catalyst component (A) and the amount of polymer produced per 1 g of solid catalyst component (A).
It represents the amount of polymer produced (kg) per gram of transition metal component in the composition.

Example 1 [Preparation of solid catalyst component (A)] Stirring device, reflux condenser,
Put 7 g (0.29 mol) of metallic magnesium powder into a 1 liter flask equipped with a dropping tube and thermometer, add 0.35 g of iodine, and 29.3 g (0.49 mol) of butanol.
) and isopropanol 36.3g (0.49mol
) and zirconium tetrachloride 26.9g (0.12mol)
was added, and further 24.5 g of titanium tetrabutoxide (0
．． After adding 072 mol), the temperature was raised to 90°C, and the mixture was stirred for 2 hours under a nitrogen blanket while excluding generated hydrogen gas. Subsequently, the temperature was raised to 140°C and reaction was carried out for 2 hours to obtain a solution containing magnesium, titanium, and zirconium (Mg-Ti-Zr solution).

[0054] Then, the Mg equivalent of the obtained solution was 0.06
2 mol was placed in a 500 ml flask, heated to 45°C, 6.5 g (0.031 mol) of tetraethoxysilane was added, stirred for 1 hour, heated to 70°C, and reacted for 1 hour. Next, at 45°C, 184.4 ml (0.50 mo
After adding l), the temperature was raised to 60°C and stirred for 1 hour, and hexane was added and washed five times to obtain a solid catalyst component (A). A catalyst slurry was prepared by dispersing 1.0 g of the obtained solid catalyst component (A) in 100 ml of a solvent (IP-1620 manufactured by Idemitsu Petrochemical Co., Ltd.) whose main component is isoparaffin having 10 to 11 carbon atoms. [Ethylene polymerization] A stainless steel autoclave with an internal volume of 1 liter and equipped with an induction stirrer was replaced with nitrogen, and IP-162
0 was added thereto, and the temperature was raised to 220° C. with stirring. The vapor pressure of the solvent is about 1.0 kg/cm2G in the system, but ethylene is charged until the total pressure reaches 7.0kg/cm2G, and the catalyst slurry of the solid catalyst component (A) is 6.4 kg/cm2G.
1 mg (0.02 mmol) and 0.2 mmol of triethylaluminum as catalyst component (B) were added to start polymerization.

When ethylene was continuously introduced and polymerization was carried out for 4 minutes while keeping the total pressure constant, 33.3 g of polymer was obtained. Polymerization activity per catalyst is 5.20 kg/g
It was a catalyst. Activity per transition metal component is 24.0k
g/g (Ti+Zr). MFR is 0.16
g/10 minutes.

Examples 2 and 3 Except for using dimethylpolysiloxane in Example 2 and methylhydropolysiloxane in Example 3 instead of tetraethoxysilane, which is the silicon compound (iv) used in Example 1, respectively. A solid catalyst component (A) was prepared under the same conditions as in Example 1, and ethylene was polymerized using the catalyst component (B). The results are shown in Table 2.

Examples 4 and 5 In Example 4, the zirconium compound used in Example 1 (
Example 1 except that tetrabutoxyzirconium is used instead of zirconium tetrachloride, which is iii).
It was prepared under the same conditions. In Example 5, the solid catalyst component (A) was prepared under the same conditions as in Example 2, except that tetrabutoxyzirconium was used instead of zirconium tetrachloride, which was the zirconium compound (iii) used in Example 1. was prepared, and ethylene was polymerized using the catalyst component (B).

Example 6 The solid catalyst component (
A) was prepared, and ethylene was polymerized using the catalyst component (B). Example 7 Magnesium chloride (2
Solid catalyst component (A) was prepared under the same conditions as in Example 1, except that 7.6 g) was used, and ethylene polymerization was carried out using catalyst component (B).

Comparative Example 1 A solid catalyst component (A) was prepared under the same conditions as in Example 1, except that zirconium tetrachloride, which is the zirconium compound (iii) used in Example 1, was not used. Polymerization of ethylene was carried out using component (B).

Examples 8 and 9 In Example 8, the solid catalyst component (A) obtained in Example 1
Copolymerization with ethylene/1-butene was carried out for 20 minutes using the catalyst component (B). In Example 9, Example 8
Copolymerization was carried out using 1-hexene instead of the 1-butene used in .

[0061] The catalyst activity lasted for 20 minutes, indicating a long lifetime of activity. The results are shown in Table 3.

Comparative Example 2 The solid catalyst component (A) and catalyst component (B) used in Comparative Example 1 were
) under the same conditions as in Example 8. As a result, the density was 0.929 g/cm3, which was higher than in Example 8, and the copolymerizability was poor. Furthermore, the persistence of activity was not good.

Examples 10 to 14 In Example 10, the same procedure as in Example 8 was used except that a mixture of triethylaluminum and diethylaluminium chloride (molar ratio 1/1), which was the catalyst component (B), was used. Copolymerization was carried out under the following conditions. In Example 11, the ratio of triethylaluminum and diethylaluminum chloride used in Example 10 was changed (molar ratio 4/1). In Example 12, the mixture was changed to diethylaluminium chloride and diethylaluminium ethoxide (molar ratio 1/1). Further, in Example 13, triisobutylaluminum and diethylaluminum chloride (molar ratio 1/1)
In Example 14, except for changing to triethylaluminum and methylalumoxane (molar ratio 1/1),
Copolymerization was carried out under the same conditions as in Example 8.

Examples 15 and 16 In Example 15, copolymerization was carried out in the same manner as in Example 9, except that the same catalyst component (B) as in Example 10 was used. Example 1
In Example 6, the same solid catalyst component (A) and catalyst component (B) as in Example 8 were used, and the amount of 1-butene was doubled for copolymerization.

Examples 17 to 19 Example 17 is the same as Example 10, Example 18 is the same as Example 1.
Example 19 had the same catalyst components as Example 12 (B
), and using the same solid catalyst component (A) as in Example 4, ethylene/1-butene copolymerization was carried out.

Example 20 Zirconocene dichloride (1.2
g), and then toluene was distilled off under reflux to obtain a solid catalyst component (A).

[0067] The above solid catalyst component (A) 6.00 mg (0
．． When polymerization was carried out under the same conditions as in Example 1 using 020 mmol), 15.6 g of polymer was obtained. The polymerization activity per catalyst was 2.60 kg/g catalyst, corresponding to 11.2 kg/g per transition metal component (Ti+Zr). MFR was 0.08 g/g 10 minutes.

Example 21 6.60 mg of solid catalyst component (A) used in Example 20
(0.022 mmol) and methylalumoxane (0.022 mmol) instead of triethylaluminum as the catalyst component (B).
Polymerization was carried out under the same conditions as in Example 1, except that 2.0 mmol) was used. The obtained polymer weighed 34.6g.
The polymerization activity per catalyst was 5.24 kg/g catalyst, and the polymerization activity per transition metal component was 22.6 kg/g (Ti+Zr
). MFR was 10.3 g/g 10 minutes.

[Brief explanation of drawings]

[Figure 1] Catalyst preparation diagram (flow chart) in the present invention
shows.

[Table 1]

[Table 2]

[Table 3]

Claims (1)

[Claims] Claim 1: In polymerizing ethylene or copolymerizing ethylene with at least one α-olefin in the presence of a catalyst consisting of a transition metal compound and an organometallic compound at a reaction temperature higher than the melting point of the polymer, the following method is used: (i) ~ (v
Component (A) is a transition metal solid catalyst component obtained by reacting a compound of organic compound (ii) at least one titanium compound selected from an oxygen-containing organic compound of titanium and a halogen-containing compound; (iii) at least one zirconium compound selected from an oxygen-containing compound of zirconium and a halogen-containing compound; (iv) selected from polysiloxane and silanes;
at least one silicon compound, and (v) at least one halogenated organoaluminium compound, and (B) component having the general formula AlR1j(OR2)kX3-k (wherein R1 and R2 are 1 to 20 carbon atoms X represents a halogen atom, j represents 0<j≦3, k represents 0≦k≦2, and represents a number such that 0<j+k≦3) A method for producing polyethylene, characterized in that a catalyst system comprising at least one organoaluminum compound from the group represented by aluminoxane or aluminoxane is used.