JPH0570519A - Production of ultrahigh-molecular-weight polyethylene - Google Patents

Abstract

PURPOSE:To produce an ultrahigh-molecular-weight polyethylene with an intrinsic viscosity [eta] of at least 5dl/g and a good granular shape. CONSTITUTION:An ultrahigh-molecular-weight polyethylene is produced by the use of a catalyst system comprising a solid catalyst component and at least one member selected from organo-Al compounds. The solid catalyst component is produced by reacting at least one organo-Al halide with a homogeneous solution containing at least one member selected from the group consisting of metallic Mg, organic hydroxide compounds and organic oxygen compounds of Mg, at least one Zr compound selected from halogen compounds and organic oxygen compounds of Zr, and at least one Si compound selected from polysiloxanes and silanes.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing ultra high molecular weight polyethylene. More specifically, by using a novel solid catalyst component containing a magnesium compound and a zirconium compound and an organoaluminum compound, an ultrahigh molecular weight polyethylene having a good particle shape and an intrinsic viscosity [η] of 5 dl / g or more is produced. Regarding the method.

[0002]

2. Description of the Related Art In general, the solid physical properties of polyethylene change as the molecular weight increases, and ultra-high molecular weight polyethylene having an extremely large intrinsic viscosity [η] of 5 dl / g or more has an intrinsic viscosity [η] of less than 5 dl / g. Compared with other general polyethylene, it has excellent properties such as abrasion resistance, impact resistance, self-lubricating property and solvent resistance. Due to these characteristics, ultra high molecular weight polyethylene is used as one of engineering plastics. In particular, ultra-high-molecular-weight polyethylene has characteristics that it can be made lighter due to its low specific gravity, is superior in electrical insulation and low-temperature characteristics, and is cheaper than other engineering plastics. Also, regarding the problem of workability, which has been cited as a drawback of ultra-high molecular weight polyethylene in the past, due to the remarkable progress of processing methods in recent years, it is possible to supply various shapes of products to the market by press molding, injection molding, etc. Became. For these reasons, ultra high molecular weight polyethylene is used in a wide range of fields such as mining, food, agriculture, civil engineering machinery, sports, and leisure. Furthermore, the application of technology such as oriented crystallization from solution or wet spinning method, and its application as high strength and high elastic modulus fiber is drawing attention, and the demand for ultra high molecular weight polyethylene is expected to grow further in the future. It

[0003] Conventionally, for the production of ultrahigh molecular weight polyethylene, many systems using a solid catalyst component containing a magnesium compound and a titanium compound and an organometallic component are known.
Also, because ultra-high molecular weight polyethylene has poor flowability during molding, it is difficult to pelletize it like ordinary polyethylene, and the powder obtained during polymerization can be press-molded or extruded or dissolved in a solvent. After that, it is formed by a method of forming fibers by gel spinning. In this case, since the particle shape of the powder greatly contributes to the molding productivity, ultrahigh molecular weight polyethylene having a good particle shape is desired.

However, when the above titanium-based catalyst is used, it is difficult to obtain a sufficiently large molecular weight under the condition that the polymerization temperature, which is usually high in the art, and the polymerization temperature is 80 ° C. or higher. Therefore, with the titanium-based catalyst, it is unavoidable to produce ultra-high molecular weight polyethylene under the condition that the polymerization temperature is lowered at the expense of productivity. On the other hand, a catalyst system using zirconium instead of titanium can be used for the production of ultra-high molecular weight polyethylene, but conventional zirconium-based catalysts have poor powder shape, and therefore they can be used for the production of ultra-high molecular weight polyethylene. It was not suitable.

In order to improve the transparency and other qualities of polyethylene, an α-olefin such as butene-1 is usually reacted as a comonomer, but in general, co-monomer introduction causes chain transfer and termination of the growth reaction. The molecular weight of the polymer is lower than that of the homopolymer of ethylene under the same conditions. Therefore, it is desired to develop a catalyst for producing polyethylene having a molecular weight sufficient to exhibit the physical properties characteristic of ultra-high molecular weight polyethylene in copolymerization.

[0006]

Therefore, the present inventors have
As a result of intensive studies on a catalyst system capable of producing ultrahigh molecular weight polyethylene, a novel solid catalyst component containing a magnesium compound and a zirconium compound was found to have a polymerization temperature of 8%.
The present invention has been completed by finding a method for producing a polymer having a sufficient molecular weight as an ultrahigh molecular weight polyethylene in a good particle shape even if the polymerization is carried out at 0 ° C. or higher or in the presence of α-olefin. ..

That is, according to the present invention, in the production of ultra-high molecular weight polyethylene in the presence of a catalyst composed of a transition metal compound and an organometallic compound, (I) metal magnesium and a hydroxylated organic compound, magnesium At least one member selected from the group consisting of oxygen-containing organic compounds, (II) at least one zirconium compound selected from oxygen-containing organic compounds of zirconium and halogen-containing compounds, (III) selected from polysiloxanes and silanes At least one selected from an organoaluminum compound (IV) as a solid catalyst component prepared by reacting at least one organoaluminum halide with a homogeneous solution containing at least one silicon compound, and (B) a component. Using a catalyst system consisting of It is in a method for producing a characteristic ultrahigh molecular weight polyethylene.

[0008]

The following are examples of the above-mentioned (I) metal magnesium and a hydroxylated organic compound or an oxygen-containing organic compound of magnesium which are the reactants used in the present invention.

First, in the case of using metallic magnesium and an organic hydroxide compound, various forms of metallic magnesium can be used, that is, any shape such as powder, particles, foil or ribbon can be used. Suitable compounds are alcohols and organic silanols.

As the alcohol, an alcohol having a hydrocarbon group having 1 to 18 carbon atoms such as an alkyl group and a cycloalkyl group can be used. Examples include methanol, ethanol, n-propanol, i-
Propanol, n-butanol, i-butanol, n-
Hexanol, 2-ethylhexanol, n-octanol, n-stearyl alcohol, cyclopentanol, ethylene glycol and the like can be mentioned.

The organic silanol has at least one hydroxyl group, and the organic group has 1 to 12 hydroxyl groups.
Selected from compounds having a hydrocarbon group such as an alkyl group, a cycloalkyl group and an aryl group, each having 1 carbon atom, preferably 1 to 6 carbon atoms. Examples thereof include trimethylsilanol, triethylsilanol, triphenylsilanol, t-butyldimethylsilanol and the like.

These hydroxylated organic compounds are used alone or as a mixture of two or more kinds.

In addition, when the solid catalyst component of the component (A) described in the present invention is obtained by using metallic magnesium, it reacts with metallic magnesium or produces an addition compound for the purpose of promoting the reaction. Such substances, for example, polar substances such as iodine, alkyl halides, organic acid esters and organic acids are preferably added alone or in combination of two or more.

Next, as compounds belonging to the oxygen-containing organic compound of magnesium, magnesium alkoxides such as methylate, ethylate, isopropylate, decalate, cyclohexanolate and the like, magnesium alkylalkoxides such as ethyl ethylate and the like, enolates. Examples thereof include acetylacetonate and the like.

These oxygen-containing organomagnesium compounds are used alone or as a mixture of two or more kinds.

As the oxygen-containing organic compound of zirconium and the halogen-containing compound which are the reactants of (II), compounds represented by the general formula [ZrO _a (OR ¹ ) _b X ¹ _c ] _n are used. .. However, in the general formula, R ¹ represents a hydrocarbon such as an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, X ¹ represents a halogen atom, and F, Cl, Br,
Or I. a, b and c are a ≧ 0 and b ≧ 0,
It is a number compatible with the valence of zirconium when 4 ≧ c ≧ 0, and n is an integer. Above all, a is 0 ≦ a ≦ 1
It is desirable to use a compound in which n is 1 ≦ n ≦ 6.

As a concrete example, Zr (OC ₂ H ₅ )
_{4, Zr (O-n-} C 3 H 7) 4, Zr (O-i-C 3
_{H 7) 4, Zr (O} -n-C 4 H 9) 4, ZrF 4, Z
_{rCl 4, ZrOF 2, ZrOCl 2} , Zr (O-n-
_{C 4 H 9) Cl 3,} Zr (O-n-C 4 H 9) 2 C
_{l 2, Zr (OC 2 H} 5) 3 Cl, Zr (O-i-C 3
H ₇₎ such as _{Cl 3, Zr (O-n} -C 3 H 7) Cl 3 and the like. Also within the scope of the invention is the use of compounds containing several different hydrocarbon groups.

The oxygen-containing organic compound and the halogen-containing compound of zirconium are used alone or as a mixture of two or more kinds.

As the silicon compound of the above (III),
The following polysiloxanes and silanes are used.

The polysiloxane may be represented by the general formula:-(Si (R ² ) (R ³ ) -O-) _1- (wherein R ² and R ³ are alkyl groups having 1 to 12 carbon atoms, aryl groups, etc. Represents a silicon-bondable atom or residue such as a hydrocarbon group, hydrogen, halogen, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group, and a fatty acid residue,
R ² and R ³ may be of the same kind or different kinds, and 1 usually represents an integer of 2 to 10000), and one or more kinds of repeating units represented by A siloxane polymer having a linear, cyclic or three-dimensional structure (provided that all R ² and R ³ are
Hydrogen hydrogen or halogen is excluded).

Specifically, hexamethyldisiloxane,
Octamethyltrisiloxane, dimethylpolysiloxane, methylhydropolysiloxane, ethylhydropolysiloxane, diphenylpolysiloxane, methylphenylpolysiloxane, dimethoxypolysiloxane, diethoxypolysiloxane, hexamethylcyclotrisiloxane, 2,4,6-trimethyl Examples thereof include cyclotrisiloxane and hexaphenylcyclotrisiloxane.

It is desirable that these polysiloxanes be liquid for handling, and have a viscosity at 25 ° C. of 1 to 100.
It is desirable to be in the range of 00 centistokes, preferably 1-1000 centistokes.

Examples of silanes include the general formula H _r Si
_s R ⁴ _t X ² _u (In the formula, R ⁴ is a hydrocarbon group such as an alkyl group having 1 to 12 carbon atoms or an aryl group, an alkoxy group having 1 to 12 carbon atoms, an allyloxy group, a silicon such as a fatty acid residue. Each R ⁴ may be different or the same kind, X ² represents a different kind or the same kind of halogen, and is F, Cl, Br or I.
r, t, and u are integers of 0 or more, and s is a natural number).

Specifically, silane hydrocarbons such as trimethylphenylsilane and allyltrimethylsilane,
Chain-like and cyclic organic silanes such as hexamethyldisilane and octaphenylcyclotetrasilane, organic silanes such as methylsilane, dimethylsilane and trimethylsilane, silicon halides such as silicon tetrachloride and silicon tetrabromide, dimethyldichlorosilane, diethyl Alkyl and aryl halogenosilanes such as dichlorosilane, diphenyldichlorosilane, triethylfluorosilane, dimethyldibromosilane, dimethyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, diphenyldiethoxysilane, triphenylethoxysilane, dimethyltetraethoxydisilane, etc. Alkoxysilanes, dichlorodiethoxysilane, dichlorodiphenylsilane, tribromoethoxysilane and other haloalkoxy and phenoxysilanes Acetoxytrimethylsilane, diethyl diacetoxy silane, silane compounds containing fatty acid residue such as ethyltriacetoxysilane, and the like.

The above organosilicon compounds may be used alone, or two or more kinds may be mixed or reacted and used.

As the halogenated organoaluminum compound which is the reaction agent of the above (IV), the general formula AlR ⁵ _k X ^{3 is used.}
Those indicated by _3-k can be used. However, in the general formula, R ⁵ is a hydrocarbon group containing 1 to 20, preferably 1 to 6 carbon atoms, X ³ represents halogen, and is F, Cl, Br or I. k is 0
<K <3. Preferably R ⁵ is selected from linear or branched alkyl, alkoxy groups, cycloalkyl groups, aryl groups and the like.

The above-mentioned aluminum halide compounds can be used alone or as a mixture of two or more kinds.

Specific examples of the halogenated organoaluminum compound (IV) include ethyl aluminum dichloride, n-propyl aluminum dichloride, n-butyl aluminum dichloride, i-butyl aluminum dichloride, sesquiethyl aluminum chloride and sesqui-i. -Butyl aluminum chloride, diethyl aluminum chloride, di-i-propyl aluminum chloride, di-i-butyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide and the like.

Reactants (I) (II) used in the present invention
The amount of (III) (IV) used is not particularly limited,
The molar ratio of the magnesium atom of the reactant (I) to the zirconium atom of the reactant (II) is 1: 0.01 to 1:20,
In particular, it is preferable to select the usage amount so as to be 1: 0.05 to 1: 5.

The ratio of the magnesium atom of the reactant (I) to the silicon atom of the reactant (III) is 1: 0.01 to 1: 2.
It is preferable to select the amount used so as to be 0, preferably 1: 0.05 to 1: 5.

The molar ratio of the magnesium atom of the reactant (I) to the aluminum atom of the reactant (IV) is 1: 0.1.
It is preferred to choose the amount of reactants to be in the range of 1: 100, preferably 1: 1 to 1:20.

The catalyst preparation reaction is preferably carried out in a liquid medium. Therefore, it can 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 reactant is insufficient. As the inert organic solvent, any of those usually used in the art can be used, but aliphatic,
Examples thereof include alicyclic or aromatic hydrocarbons, halogen derivatives thereof, and mixtures thereof. For example, isobutane, hexane, heptane, cyclohexane, benzene, toluene, xylene, monochlorobenzene and the like are preferably used.

Reactants (I), (II) and (III)
The reaction condition for obtaining a homogeneous solution is usually -50 to 30.
At a temperature of 0 ° C., preferably 0 to 200 ° C.,
It is carried out at normal pressure or under pressure in an inert gas atmosphere for 5 to 50 hours, preferably 1 to 6 hours. Furthermore, the reaction agent (I
In the reaction of V), the temperature is generally -50 to 200 ° C, preferably -30 to 100 ° C, and 0.2 to 50.
The solid catalyst component (A) by performing the reaction in an inert gas atmosphere or under pressure for a time, preferably 0.5 to 5 hours.
Becomes

The solid catalyst component (A) may be used as it is, but generally, the remaining unreacted substances and by-products are removed by filtration or decantation, and then washed with an inert solvent several times. After that, it is preferably used by suspending it in an inert solvent. In addition, it is also possible to use a product which is isolated after washing and heated under normal pressure or reduced pressure to remove the solvent.

Further, in using the solid catalyst component (A), 0.01 to 50 g of ethylene or an α-olefin having 3 or more carbon atoms is added to 1 g of the solid catalyst component (A) in an inert hydrocarbon solvent. It is desirable to pre-polymerize. The monomers used in the prepolymerization may be used alone or in combination of two or more.
Prepolymerization can be carried out sequentially or simultaneously. In the prepolymerization, the organoaluminum compound is preferably used in a proportion of 0.1 to 1000 with respect to the titanium atom in the solid catalyst component (A). Further, the electron donating compound is added in an amount of 0.01 to 10 relative to the titanium atom in the solid catalyst component (A).
It can also be used in the ratio.

In the present invention, an organoaluminum compound is used as the catalyst component (B).

As the organic group of the catalyst component (B), an alkyl group can be mentioned as a representative. As this alkyl group, an alkyl group having 1 to 20 carbon atoms is used.
Specific examples include trimethylaluminum, triethylaluminum, tri-i-butylaluminum, tri-n-butylaluminum, tri-n-decylaluminum and the like. Above all, carbon number 1-10
Preference is given to using trialkylaluminiums having an alkyl group of Further, an alkylaluminum halide having an alkyl group having 1 to 20 carbon atoms such as sesquiethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride or an alkylaluminum alkoxide such as diethylaluminum ethoxide can be used.

These organoaluminum compounds are used alone or as a mixture of two or more kinds.

In the practice of the present invention, the solid catalyst component (A) is used in an amount corresponding to 0.001 to 2.5 mmol of titanium atom per liter of solvent or per liter of reactor internal volume. Is preferred, and higher concentrations may be used depending on the conditions.

The organoaluminum compound as the catalyst component (B) is added per 1 l of the solvent or 1 l of the internal volume of the reactor.
It is used at a concentration of 0.02 to 50 mmol, preferably 0.2 to 5 mmol.

Polymerization of ethylene or ethylene with another α-olefin is carried out in a liquid phase or a gas phase. Polymerization is carried out in the presence or absence of an inert gas with oxygen and water being substantially cut off.

When the polymerization is carried out in the liquid phase, it is preferable to use an inert solvent. This inert solvent may be any of those commonly used in the art, in particular alkanes having 4 to 20 carbon atoms, cycloalkanes such as isobutane, pentane, hexane, heptane, cyclohexane and the like. Is appropriate. When the polymerization is carried out in the gas phase, it is carried out at a temperature below the melting point of the polymer.

As the reactor used in the polymerization step, a fluid bed type reactor, a stirring tank type reactor or the like which is commonly used in the art can be appropriately used. When using a fluidized bed reactor in gas phase polymerization,
By blowing a gaseous olefin and, if necessary, an inert gas into the system, the reaction system is kept in a fluid state. When a stirring tank reactor is used, various types of stirrers such as an Ikari type stirrer, a screw type stirrer, and a ribbon type stirrer can be used as the stirrer.

The polymerization of the present invention includes not only homopolymerization of ethylene but also copolymerization of ethylene with other α-olefins. Examples of the α-olefin used for the copolymerization include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and mixtures thereof. In addition, 2 of the above α-olefin
Copolymerization can also be carried out using a mixture of one or more species.
The amount of the α-olefin used must be selected according to the density of the target polymer. The density of the polymer according to the present invention can be manufactured in the range of 0.900 to 0.950 g / cm ³ .

The polymerization operation of the present invention can be carried out not only in the usual one-step polymerization carried out under one polymerization condition, but also in the multi-step polymerization carried out under a plurality of polymerization conditions.

The polymerization conditions in the present invention are a polymerization temperature below the melting point of the polymer, for example, a polymerization temperature of 20 to 100 ° C., and a polymerization pressure of ^{2 to} 50 kg / cm ² G in the form of a slurry or a gas phase method. The molecular weight can be adjusted by a known method, that is, by allowing a suitable amount of hydrogen to exist in the reaction system.

[0047]

EXAMPLES The present invention will be shown below with reference to examples, but the present invention is not limited to these examples.

The activity represents a polymer production amount (g) per 1 g of the solid catalyst component (A).

The molecular weight of ultra-high molecular weight polyethylene is determined as the intrinsic viscosity [η] in decalin at 135 ° C. The larger this value, the larger the molecular weight of polyethylene.

The degree of short chain branching was quantified by a Fourier transform infrared spectrophotometer (FT-IR) from a peak derived from a methyl group appearing near 1378 cm ^-1 . Density is JI
It measured according to SK-6760.

Example 1 (a) [Preparation of Mg-Zr homogeneous solution] 3 l equipped with a stirrer, a reflux condenser, a dropping pipe and a thermometer
25g of magnesium metal powder (1.03
mol), and iodine 1.25 g, n-butanol 152.6 g (2.06 mol) and zirconium tetrabutoxide 80% n-butanol solution 19
7.8g (zirconium tetrabutoxide 0.41mo
85 ° C. after adding 1,3, n-butanol 0.53 mol)
The temperature was raised up to, and the mixture was stirred for 2 hours under a nitrogen blanket while removing generated hydrogen gas. Continue to raise the temperature to 140 ℃,
The reaction was carried out for 2 hours under a nitrogen blanket. Next, after cooling to 110 ° C., 48.6 g (0.32 mo) of tetramethoxysilane
l) and 66.2 g of tetraethoxysilane (0.32 mo
After adding the solution obtained by mixing 1), the temperature was raised to 140 ° C.,
The reaction was carried out for 2 hours under a nitrogen blanket. The temperature was lowered to 110 ° C., and 1750 ml of hexane was added to obtain a homogeneous solution containing magnesium and zirconium (Mg—Zr solution). (B) [Preparation of solid catalyst component (A)] Then, the obtained homogeneous solution was converted into Mg in an amount of 0.163 mol.
Was placed in a 1-liter flask and heated to 45 ° C., and 393 ml of a 50% hexane solution of i-butylaluminum dichloride was added.
(1.06 mol) was added over 2 hours. After adding all, the temperature was raised, the temperature was raised to 70 ° C., and the reaction was performed for 1 hour. Hexane was added to the product and washed 5 times to obtain a solid catalyst component (A). (C) [Polymerization] A stainless steel electromagnetic stirring type reactor having an internal volume of 2 l was sufficiently replaced with nitrogen, 1.2 l of hexane was charged, and the internal temperature was adjusted to 80 ° C. Then, 0.578 g of triisobutylaluminum and 64 mg of the solid catalyst component (A) were sequentially added as the catalyst component (B). After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen, polymerization was carried out for 1.5 hours while ethylene was continuously added so that the internal pressure of the autoclave became 7.0 kg / cm ² G. After completion of the polymerization, the mixture was cooled, unreacted gas was expelled, polyethylene was taken out, separated from the solvent by filtration and dried.

As a result, 322 g of polyethylene was obtained, and the activity was 5000 g / g catalyst. The measured [η] of the polymer was 30.1 dl / g, and the density was
It was 0.934 g / cm ³ . The bulk density is 0.3
It was 7 g / cm ³ and had good particle size distribution and good fluidity.

When this polymer was press-molded at 150 ° C., the surface was smooth and the transparency was good.

Comparative Example 1 A solid catalyst component was prepared by using a titanium compound instead of the zirconium compound as the reactant (II). That is, 11 g (0.45 mol) of metal magnesium powder was put into a 1.6 l autoclave equipped with a stirrer,
0.55 g of iodine and 70 g of n-butanol (0.
94 mol) and 61 g of titanium tetrabutoxide
(0.18 mol) was added, the temperature was raised to 80 ° C., and the mixture was stirred for 1 hour under a nitrogen blanket while eliminating generated hydrogen gas. Subsequently, the temperature was raised to 120 ° C. and the reaction was carried out for 1 hour. Furthermore, at 120 ° C., methylhydropolysiloxane (2
Viscosity at 5 ℃ about 30 centistokes) 26 ml
(0.45 gram atom of silicon) is press-fitted with nitrogen,
A reaction product was obtained by reacting at 20 ° C. for 1 hour.

Part of the above reaction product (0.053 m in terms of Mg)
ol and Si corresponding to 0.053 gram atom) 5
Into a 00 ml flask, the temperature was raised to 45 ° C. and 50% hexane solution of i-butylaluminum dichloride in hexane 10
8 ml (0.29 mol) was added over 2 hours, after adding all, it heated up and stirred at 70 degreeC for 1 hour. Hexane was added to the product and washed 15 times by the gradient method to obtain a solid catalyst component.

Using this solid catalyst component and triisobutylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1. The results are shown in Table 1, and the molecular weight was lower than when the zirconium compound was used.

When this polymer was press-molded at 150 ° C., the surface was uneven and the moldability was poor.

Comparative Example 2 1 liter equipped with a stirrer, a reflux condenser, a dropping pipe and a thermometer
In a flask of 9g, 9g of metal magnesium powder (0.37m
ol), 0.45 g of iodine, 57.7 g (0.78 mol) of n-butanol and 70.3 g of an 80% n-butanol solution of zirconium tetrabutoxide.
(Zirconium tetrabutoxide 0.15 mol, n-
(Butanol 0.19 mol) was added, and the temperature was raised to 85 ° C.
Stir for hours. Subsequently, the temperature was raised to 140 ° C. and the reaction was carried out for 2 hours under a nitrogen blanket. The temperature was lowered to 110 ° C., and hexane 630 was added without adding the silicon compound as the reactant (III).
ml was added to obtain a uniform solution containing magnesium and zirconium (Mg-Zr solution).

Then, the obtained homogeneous solution was converted into Mg of 0.
Place 131 mol in a 1 liter flask, bring to 45 ° C., and
273 ml (0.73 mol) of a 50% hexane solution of butyl aluminum dichloride was added over 2 hours.
After adding all, the temperature was raised, the temperature was raised to 70 ° C., and the mixture was stirred for 1 hour. Hexane was added to the solid component and washed 5 times to obtain a solid catalyst component (A).

Using this solid catalyst component (A) and triisobutylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1. The results are shown in Table 1, but the bulk density was low and the particle shape was poor.

Example 2 0.041 mol of the Mg-Zr homogeneous solution obtained in Example 1 (a) in terms of Mg was added to a 500 ml flask and the temperature was raised to 45 ° C. to obtain 152 ml of a 50% hexane solution of i-butylaluminum dichloride ( 0.41 mol) was added over 2 hours. After adding everything, heat up to 70
The temperature was raised to 0 ° C. and the mixture was stirred for 1 hour. Hexane was added to the product and washed 5 times to obtain a solid catalyst component (A). Using the solid catalyst component (A) and triisobutylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1. The results are shown in Table 1.

Example 3 By the same method as in Example 1 except that dimethylpolysiloxane (viscosity of 200 centistokes at 25 ° C.) was used as the compound of the reaction agent (III) used for producing the solid catalyst component (A). A solid catalyst component (A) was prepared.
Using the solid catalyst component (A) and triisobutylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1. The results are shown in Table 1.

Examples 4 to 5 The solid catalyst component (A) was prepared in the same manner as in Example 1 except that the compound of the reactant (IV) used for producing the solid catalyst component (A) was changed. That is, the solid catalyst component (A) was prepared using ethyl aluminum dichloride in Example 4 and sesquiethyl aluminum chloride in Example 5. Using these solid catalyst components (A) and triisobutylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1.

Example 6 1 liter equipped with a stirrer, a reflux condenser, a dropping pipe and a thermometer
In a flask of 7g, metal magnesium powder 7g (0.29m
ol), 0.35 g of iodine, 60.0 g (0.29 mol) of tetraethoxysilane and 75.0 g (1.01 mol) of n-butanol were added thereto, and then the temperature was raised to 85 ° C. to generate hydrogen. Stirred under a nitrogen blanket for 2 hours with exclusion of gas. Subsequently, the temperature was raised to 120 ° C., and the reaction was performed for 2 hours under a nitrogen blanket. Then, after cooling to 60 ° C., 26.9 g (0.12 mol) of zirconium tetrachloride
After adding, the temperature was raised again to 120 ° C. and the reaction was carried out for 1 hour. 200 ml of hexane was added to obtain a homogeneous solution containing Mg and zirconium (Mg-Zr solution). The subsequent operation is performed in the same manner as in Example 1, and the solid catalyst component (A) is used.
Got Using this solid catalyst component (A) and triethylaluminum, ethylene was polymerized under the same conditions as in (c) of Example 1. The results are shown in Table 1. Example 7 1.88 g of the solid catalyst component (A) obtained in Example 1
After suspending in 00 ml of hexane, 1.81 g of triethylaluminum and 0.23 g of diphenyldimethoxysilane were added. Subsequently, the pressure is 1 to ² kg / cm ² at 30 ° C.
Propylene was supplied while maintaining G, and propylene was 5.6.
4 g was reacted and the solid catalyst component (A) was prepolymerized with propylene.

A stainless steel electromagnetic stirring type reactor having an internal volume of 2 liters was sufficiently replaced with nitrogen, and 200 g of salt dried at 200 ° C. for 30 hours was added as a dispersion medium to adjust the internal temperature to 80 ° C. Then, 113 mg of catalyst obtained by prepolymerizing 0.31 g of triisobutylaluminum as the catalyst component (B) and the above-mentioned solid catalyst component (A) with propylene.
(Including 28 mg of the solid catalyst component (A)) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen, the butene-1 / ethylene (molar ratio) in the gas phase was adjusted to 0.
The internal pressure of the autoclave is 1 while adjusting to 35.
Polymerization was carried out for 1.5 hours while ethylene and butene-1 were continuously added so as to obtain 7.0 kg / cm ² G. After the completion of the polymerization, the mixture was cooled, unreacted gas was expelled, and a mixture of the produced polymer and salt was taken out. The mixture was washed with pure water, dissolved in sodium chloride and then dried to obtain a polymer.

As a result, 123 g of a polymer was obtained, and the activity was 4,400 g / g catalyst. [Η] of the polymer was measured to be 14.4 dl / g, and the density was 0.922 g / c.
At m ³ , the number of ethyl branches was 13.1 per 1000C. Further, the bulk density was 0.31 g / cm ³ , and the fluidity was narrow and the particle size distribution was good.

When this polymer was press-molded at 150 ° C., its surface was smooth and its transparency was good. Furthermore,
The gloss was superior to that of ethylene homopolymer.

[0068]

[Table 1]

[0069]

The effect of the present invention is that, firstly, the molecular weight of the polymer obtained is extremely large, and an ultrahigh molecular weight polyethylene excellent in abrasion resistance, impact resistance, self-lubricating property, solvent resistance and the like. Can be manufactured. Further, even when the α-olefin is copolymerized as a comonomer, a polymer having a sufficiently large molecular weight can be obtained, and therefore,
It is possible to produce ultra-high molecular weight polyethylene having excellent properties of linear low density polyethylene (LLDPE), such as transparency, gloss and ESCR.

The second effect of the present invention is that the powder characteristics of the polymer are remarkably excellent, and it is suitable for slurry polymerization and gas phase polymerization. That is, according to the present invention, a polymer having a narrow particle size distribution and a high bulk density can be obtained, and the dispersibility of the polymer in the polymerization system is good. These things have industrially great significance. That is, in the polymerization step, the formation of deposits in the polymerization apparatus is prevented, the polymer is easily separated, and the fine particles of the polymer are prevented from scattering outside the system. Further, in the transfer process, there is no occurrence of bridges in the silo, and transfer troubles are eliminated. Further, it becomes possible to provide a polymer having a certain quality.

The third effect of the present invention is that the workability is good, press molding is possible even at a temperature of about 150 ° C., and a molded product with a good surface condition can be obtained.

[Brief description of drawings]

FIG. 1 is a catalyst preparation diagram (flow chart) in the present invention.
Indicates.

Claims (1)

[Claims] 1. When producing ultrahigh molecular weight polyethylene in the presence of a catalyst composed of a transition metal compound and an organometallic compound, as component (A), (I) metal magnesium and a hydroxylated organic compound, an oxygen-containing organic compound of magnesium At least one member selected from the group consisting of compounds, (II) at least one zirconium compound selected from oxygen-containing organic compounds of zirconium and halogen-containing compounds, (III) at least one selected from polysiloxanes and silanes From a solid catalyst component prepared by reacting at least one kind of organoaluminum halide with a uniform solution containing the silicon compound of (4) and at least one kind selected from organoaluminum compounds as the component (B). Ultra-high molecular weight characterized by using a different catalyst system Method for producing polyethylene.