JPH0629289B2 - Method for producing polyethylene - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an ethylene polymer in which the polymerization is carried out at a reaction temperature below the melting point of the polymer in the presence of a novel catalyst system.

[Conventional technology]

It is already known to use a catalyst system composed of a transition metal compound and an organometallic compound for low-pressure polymerization of ethylene, but recently, as a highly active catalyst, a reaction product of an inorganic or organomagnesium compound and a transition metal compound has been used. A catalyst system containing as a component is widely used. For example, JP-B-52-15110, JP-B-52-39714, JP-A-56-155205, JP-A-56-151704.
Japanese Patent Application No. 59-102661, Japanese Patent Application No. 59-118
No. 120, etc., obtained by reacting an aluminum halide with a magnesium metal hydroxide organic compound or an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound or a halide of a transition metal, a silicon compound, an organoaluminum compound, and an aluminum halide. Catalyst components
An extremely active catalyst system comprising (A) and a catalyst component (B) of an organometallic compound is used.

However, the polymerization carried out in the presence of these catalyst systems usually uses hydrogen as a molecular weight regulator, and a large amount of hydrogen is required especially when lowering the molecular weight. At this time, in these Ziegler type catalyst systems having a high activity, a reaction in which a part of ethylene is hydrogenated by hydrogen to industrially disadvantageously produce ethane occurs to a nonnegligible level,
It is inconvenient. That is, as a result, the polymer yield per raw material ethylene is reduced, and the productivity is deteriorated.

Regarding the copolymerization of ethylene with a small proportion of α-olefin, JP-A-59-71307 discloses that a solid component containing magnesium and titanium having a valence of 3 or more as essential components is reduced with an organometallic compound. Then, a method for producing an ethylene copolymer having a low melting point by halogenating with a non-reducing halogen compound is disclosed. That is, it is a method of producing a copolymer having a low melting point by reducing 30% or more of titanium in the solid component to divalent valence and then using the titanium. However, in a catalyst system obtained by reacting a magnesium metal with a hydroxylated organic compound or an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of a transition metal, and an aluminum halide, a by-product during ethylene polymerization by such a method is used. It is not only difficult to suppress ethane, but the polymerization activity of the catalyst is remarkably reduced, and the powder properties of the polymer are deteriorated. I can't.

[Problems to be solved]

The method of polymerizing ethylene at a reaction temperature lower than the melting point of the polymer results in industrially disadvantageous ethane as a by-product, resulting in a decrease in the polymer yield per raw material ethylene and a drawback that productivity is deteriorated. At the same time, waste ethane produced as a by-product accumulates in the polymerization system, and is discharged out of the system. Therefore, loss of raw materials such as ethylene is unavoidable. Therefore, the present inventors have conducted extensive studies for the purpose of providing a method for polymerizing ethylene in which ethane by-product is suppressed without impairing good characteristics such as catalytic activity and powder properties. As a result, they have found a method for producing an ethylene polymer in which the industrially disadvantageous ethane by-product is prevented by combining specific catalyst components.

[Means of solution]

That is, the present invention provides a Ziegler-type catalyst having high activity, and a method for producing polyethylene in which ethylene or ethylene and an α-olefin are polymerized at a reaction temperature lower than the melting point of the polymer in the presence of hydrogen, A) (i) a product obtained by reacting titanium tetraalkoxide with a reactant comprising metallic magnesium and at least one aliphatic alcohol, (ii) at least one organoaluminum dihalide and (iii) halogen , Interhalogen compounds and tin, lead,
Solid catalyst component (A) obtained by reacting at least one halogen-containing compound selected from the group of phosphorus, antimony and sulfur halogen compounds
And (B) a catalyst component (B) of an organoaluminum compound.

[Action]

In the reaction agent composed of metallic magnesium and an aliphatic alcohol for producing the solid catalyst component (A) used in the present invention, the metallic magnesium has various shapes, that is, powder, particles, foil, ribbon or the like. Shaped ones can also be used, and as the aliphatic alcohol, 1 to 1
Straight-chain or branched-chain aliphatic alcohols having 8 carbon atoms can be used. Examples include methanol, ethanol, n-propanol, i-propanol, n-butanol, n-hexanol, 2-ethylhexanol, n.
-Examples include octanol and ethylene glycol.

These aliphatic alcohols are used alone or as a mixture of two or more kinds. Of course, it may be used alone, but when it is used as a mixture of two or more kinds, it may produce a peculiar effect on the powder characteristics of the polymer.

In addition, when using metal magnesium to obtain the solid catalyst component (A) described in the present invention, for the purpose of promoting the reaction, a substance that reacts with metal magnesium or forms an addition compound, for example, Iodo group, mercuric chloride,
It is preferable to add polar substances such as alkyl halides, organic acid esters and organic acids, singly or in combination of two or more.

Examples of the titanium tetraalkoxide for producing the solid catalyst component (A) include titanium tetrapropoxide,
Examples include titanium tetrabutoxide.

Further, the component (A) may contain an organoaluminum compound or a silicon compound in order to give a polymer having good particle properties. Further, a transition metal component other than titanium may be contained in order to broaden the molecular weight distribution of the polymer.

Examples of the organoaluminum compound used to improve the particle properties include triethylaluminum, tri-i-butylaluminum, diethylaluminum chloride,
Examples thereof include ethyl aluminum sesquichloride, ethyl aluminum dichloride, i-butyl aluminum dichloride and the like.

As the silicon compound, polysiloxane and silanes can be used. Examples of polysiloxanes include dimethylpolysiloxane, methylhydropolysiloxane, diphenylpolysiloxane, and the like, and silanes include hexamethyldisilane, tetraethoxysilane, and
Examples thereof include diphenyldiethoxysilane.

Examples of the transition metal-containing reactive agent other than the titanium compound used to broaden the molecular weight distribution of the polymer include zirconium compounds such as zirconium tetrachloride, ethoxytrichlorozirconium, dibutoxydichlorozirconium, tributoxychlorozirconium, tetrabutoxyzirconium, Vanadium compounds such as vanadium trichloride, vanadium oxytrichloride, tributoxy vanadium and the like can be used in combination.

In the organoaluminum dihalide of (ii), the organic group represents a hydrocarbon group having 1 to 20, preferably 1 to 8 carbon atoms, and a straight chain or branched chain alkyl group,
It is preferably selected from a cycloalkyl group, an arylalkyl group, an aryl group and an alkylaryl group.

Specific examples of such an organoaluminum dihalide include ethylaluminum dichloride and i-butylaluminum dichloride, which can be used alone or as a mixture of two or more kinds.

Specific examples of the halogen-containing compound (iii) include:
Chlorine, bromine, iodine halogens, iodine monochloride, iodine trichloride, fluorine trichloride, interhalogen compounds such as chlorine bromide, stannous chloride, stannic chloride, lead tetrachloride, phosphorus trichloride,
Examples thereof include phosphorus oxytrichloride, phosphorus pentachloride, antimony pentachloride, thionyl chloride and sulfuryl chloride.

The solid catalyst component (A) used in the present invention is (i)
i) and then (iii)
It can be prepared by reacting (i) with (iii) and then with (ii). Alternatively, a mixture of (ii) and (iii) in advance can be reacted with (i) for preparation.

These reactions are preferably carried out in a liquid medium. Therefore, it should 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, and examples thereof include aliphatic, alicyclic or aromatic hydrocarbons or a mixture thereof, such as isobutane, hexane, heptane, cyclohexane, Benzene, toluene, xylene, chlorobenzene, 1,2-dichloroethane and the like are preferably used.

The amount of the above-mentioned reactant used is not particularly limited, but the atomic ratio of magnesium to titanium is 1: 0.001 to 1:20, preferably 1: 0.1 to 1: 5, and the atomic ratio of magnesium to aluminum is 1: 0.1 to. 1: 100, preferably 1: 1 to 1:20, magnesium and halogen, interhalogen compound and tin,
The atomic ratio of at least one halogen-containing compound selected from the group of lead, phosphorus, antimony and sulfur halogen compounds is 1: 0.001 to 1: 1000, preferably 1: 0.005 to 1:
Further, when using a silicon compound, it is preferable to select the amount of the reactant used so that the atomic ratio of magnesium to silicon is in the range of 1: 100 or less, preferably 1:10 or less. Out of these ranges, the catalytic activity during polymerization may be lowered and the powder property of the polymer may be deteriorated. Among them, the reaction step in (iii) is important, and (i) ) Or the reaction product of (i) and (ii) and (iii) are reacted, in the reaction product of (i) or (i) or (i) and (ii),
An increase in the amount of titanium having a valence of 2 in the total titanium deteriorates the catalytic activity and the powder property of the polymer. Particularly, when the valence of divalent titanium is 30% or more, this effect becomes remarkable, so that the content of divalent titanium is preferably less than 30%.

That is, for example, when (i) and (ii) are reacted and then (iii) is reacted, a trialkylaluminum such as triethylaluminum or tri-i-butylaluminum is used instead of (ii), or When a mixture of aluminum chloride and trialkylaluminum is used, if trialkylaluminum is used excessively and excessively reduced to increase divalent titanium, good results cannot be obtained.

When an organoaluminum compound is used prior to (ii) to improve the powder properties, the amount used is such that the equivalent ratio of the organic group of the organoaluminum compound to the titanium atom is 1: 120 or less, preferably Is less than 1:60, and when it goes out of this range and becomes large, the amount of divalent titanium increases,
It should be noted that the catalytic activity and powder properties will deteriorate.

The conditions of each reaction described above are not particularly limited, but -50 to 3
At a temperature of 00 ° C., preferably 0 to 200 ° C.,
It is carried out for 5 to 50 hours, preferably 1 to 6 hours in an inert gas atmosphere at atmospheric pressure or under pressure.

Examples of the organoaluminum compound that is the catalyst component (B) used in the present invention include organoaluminum compounds composed of aluminum and an organic group. As the organic group, an alkyl group can be mentioned as a representative. As this alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is used. Examples of the organoaluminum compound having such an organic group include trimethylaluminum, triethylaluminum and tri-aluminum.
Examples thereof include i-butylaluminum, tri-n-butylaluminum, tri-n-decylaluminum and the like.
Above all, it is preferable to use a trialkylaluminum having a linear or branched alkyl group having 1 to 10 carbon atoms.

In addition, as the component (B), an alkylaluminum hydride having an alkyl group having 1 to 20 carbon atoms can be used. As such a compound, specifically,
Examples thereof include di-i-butylaluminum hydride. Further, an alkylaluminum halide having an alkyl group having 1 to 20 carbon atoms such as ethylaluminum sesquichloride, diethylaluminum chloride, di-i-butylaluminum chloride or an alkylaluminum alkoxide such as diethylaluminum ethoxide can also be used. In addition, an organoaluminum compound obtained by a reaction of a trialkylaluminum having an alkyl group having 1 to 20 carbon atoms or a dialkylaluminum hydride with a diolefin having 4 to 20 carbon atoms, for example, a compound such as isoprenylaluminum is used. You can also do it.

Further, it is also possible to use an aluminoxane compound in which two or more aluminum atoms are bound via an oxygen atom or a nitrogen atom, for example, a polymer such as tetramethylaluminoxane or polymethylaluminoxane.

In carrying out the present invention, the amount of the catalyst component (A) used is the solvent 1
0.001 per atom of titanium per reactor
It is preferable to use in an amount corresponding to ˜2.5 mmol (mmol), and higher concentration can be used depending on the conditions.

The organoaluminum compound of component (B) is used in a concentration of 0.02 to 50 mmol, preferably 0.2 to 5 mmol, per solvent or reactor.

Polymerization of ethylene is performed in a liquid phase or a gas phase.

When the polymerization is carried out in the liquid phase, it is preferable to use an inert solvent. The inert solvent may be any of those commonly used in the art,
Particularly suitable are alkanes and cycloalkanes having 4 to 20 carbon atoms, such as isobutane, pentane, hexane, cyclohexane and the like.

The polymerization according to the present invention is not limited to homopolymerization of ethylene,
It also includes the copolymerization of ethylene and α-olefins. Examples of the α-olefin used for the copolymerization include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and mixtures thereof.

The polymerization conditions in the present invention are not particularly limited as long as the reaction temperature is lower than the melting point of the polymer, but specifically, the reaction temperature is 20 to 110 ° C. and the pressure is ^{2 to} 50 kg / cm ² G. The hydrogen concentration is the hydrogen partial pressure / ethylene concentration.
The ethylene partial pressure ratio is usually selected from 0.001 to 20.

The reactor used in the polymerization step can be appropriately used as long as it is usually used in the technical field.
For example, the polymerization operation can be carried out in any of a continuous system, a semi-batch system and a batch system by using a stirred tank reactor or a circulation reactor.

〔The invention's effect〕

According to the present invention, by using a catalyst obtained by further improving the conventional catalyst that gives high polymer activity and good polymer powder, it is possible to significantly reduce the amount of ethane produced as a by-product during ethylene polymerization. . That is, according to the present invention, industrially disadvantageous ethane by-product can be suppressed and polyethylene can be produced with higher productivity than ever before.

The second effect of the present invention is that the amount of ethane produced as a by-product can be suppressed to a very low level, so that the accumulation of unnecessary ethane in the polymerization system is extremely reduced, and it has been inevitable in the past to remove this. Emission of gas in the system can be proportionally extremely reduced. Therefore, the loss of raw materials such as ethylene and hydrogen due to this discharge is minimized, and the productivity is improved. When the prevention of ethylene loss and the prevention of ethane by-product are combined, the loss of raw material ethylene can be reduced by half or 10 minutes compared to the conventional case by properly selecting the type and addition amount of the halogen-containing compound of (iii). Can be reduced to 1 or less.

The third effect of the present invention is that ethylene can be polymerized without impairing the favorable properties such as catalytic activity and powder properties in the above-mentioned conventional method. That is, the catalytic activity is high and the yield of the polymer obtained per catalyst component is remarkably large, it is not necessary to take a special means from the polymer to remove the catalyst residue, and there is a problem such as deterioration or coloring of the polymer during molding. Can be avoided.

〔Example〕

Hereinafter, the present invention will be shown by examples, but the present invention is not limited to these examples. In addition,
In Examples and Comparative Examples, HLMI / MI is high load melt index (HLMI, AXTM D-123).
8 Condition F) and melt index (MI, AST
MD-1238 (according to condition E), and the density was measured and determined by ASTM D-1505. Also,
By-produced ethane was quantified by gas chromatography, and the by-product rate [amount of by-produced ethane / amount of produced polymer × 10
0 (%)].

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

Valence divalent titanium can be found in the Journal of Polymer Science A-1, September 1971, p. 235 [J. Bo.
or, GA, Short, J.Polym, Soi., Part A-1, 9, 235
(1971)], the reaction product of (i) or the reaction product of the reaction product of (i) and the aluminum halide compound of (ii) is added with distilled water sufficiently substituted with nitrogen to generate at this time. It was quantified from the amount of hydrogen. Further, the divalent Ti / total Ti described in the following Examples and Comparative Examples is an atom in the reaction product of (i) or the reaction product of (i) with the aluminum halide compound (ii). The ratio (% by weight) of divalent titanium to total titanium is shown.

Example 1 a) Preparation of solid catalyst component (A) To a flask having a volume of 1 and equipped with a stirring device, under a nitrogen atmosphere, 4.9 g (0.20 mol) of magnesium metal powder and 27.2 g (0.08 mol) of titanium tetrabutoxide were added. , Raise the temperature to 80 ℃,
31.1 g of n-butanol in which 0.25 g of iodine was dissolved
(0.42 mol) was added dropwise over 1 hour and then heated to 120 ° C. for reaction. 340 ml of hexane was added to the reaction product thus obtained at room temperature, and then 50 wt.
124 g of ethyl aluminum dichloride diluted to 100%
(0.8 mol) was added dropwise at 45 ° C. over 2 hours. Hexane was added to this product and the product was washed by a gradient method. A small amount of this product was sampled to measure divalent titanium.
/ Total Ti was less than 1%. Then 5.6 g (0.024 mol) of iodine trichloride diluted to 5 wt% with 1,2-dichloroethane
Was added dropwise at 45 ° C., the temperature was raised to 70 ° C., and the mixture was reacted to obtain a solid catalyst component (A). The titanium content of this solid component is 9.2.
It was wt%.

b) The inside of the electromagnetic stirring reactor made of stainless steel with an internal volume of 2 was sufficiently replaced with nitrogen, hexane 1.2 was charged, and the internal temperature was adjusted to 80 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B) and 6 mg of the above component (A) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, add 13 kg / cm ² of hydrogen and perform polymerization for 1.5 hours while continuously adding ethylene so that the total pressure becomes 20 kg / cm ² G. It was After the polymerization was completed, a small amount of the gas phase portion and the liquid phase portion were sampled and the amount of ethane produced as a by-product was measured.
Further, polyethylene was taken out from the autoclave and separated from the solvent by filtration. As a result, 292 g of polyethylene was obtained, the catalytic activity was 48600, and the ethane byproduct rate was 0.009%. Also, MI is 41, HLMI
/ MI was 32 and the bulk density was 0.42 g / cm ³ .

Examples 2-3, Comparative Example 1 In the method of Example 1, an experiment was conducted by changing the amount of the component (C) iodine trichloride used. That is, in Examples 2 to 3, the amount of iodine trichloride used was changed, and in Comparative Example 1, the catalyst component (A) was prepared without using it, and the polymerization conditions were the same as in Example 1. The results are shown in Table 1.

Comparative Example 2 a) Preparation of solid catalyst component (A) In Example 1, halogenation was performed after excessive reduction of titanium using trialkylaluminum. That is, under a nitrogen atmosphere, 2.4 g (0.10 mol) of magnesium metal powder and 13.6 g (0.04 mol) of titanium tetrabutoxide were added to a flask with a capacity of 1 and equipped with a stirrer. 15.6 g (0.21 mol) of n-butanol in which iodine was dissolved was added dropwise over 1 hour, and then 12
The mixture was heated to 0 ° C. and reacted. 170 ml of hexane was added to the reaction product thus obtained at room temperature, and 62 g (0.4 mol) of ethylaluminum dichloride diluted to 50 wt% with hexane was added dropwise at 45 ° C over 2 hours. Hexane was added to this product and the product was washed by a gradient method, and then 99 g (0.5 mol) of tri-i-butylaluminum diluted to 30 wt% with hexane was added dropwise at 45 ° C over 2 hours to obtain a solid component. 82% of titanium in this solid component was reduced to divalent valence (divalent Ti / total Ti was 82%).
Equivalent to). Then, this solid component was added in the presence of hexane 20
Halogenation was carried out by supplying chlorine at 30 ° C. for 30 minutes. The titanium content of this catalyst component was 9.2 wt%. The divalent titanium in this catalyst component was reduced to 15%.

b) Polymerization The polymerization experiment of Example 1 was repeated, except that 15 mg of the above solid component was used. As a result, 226 g of polyethylene was obtained, the catalytic activity was 15100, and the ethane byproduct rate was 0.20.
It was 3%. Also, MI is 43 and bulk density is 0.34 g / c.
It was m ³ .

Example 4 a) Preparation of solid catalyst component (A) 70 g (0.94 mol) of n-butanol was placed in an autoclave of 1.6 equipped with a stirrer, and 0.55 of iodine was added thereto.
g, metallic magnesium powder 11 g (0.45 mol) and titanium tetrabutoxide 38 g (0.11 mol), and then hexane (770 ml) is added and the temperature is raised to 80 ° C. If the generated hydrogen gas is eliminated, it is kept under a nitrogen blanket for 1 hour. I was agitated. Then, the temperature is raised to 120 ° C and the reaction is performed for 2 hours.
A solution containing magnesium and titanium was obtained.

0.05 mol of the solution containing magnesium and titanium in terms of Mg was added to a flask having an internal volume of 500 ml, the temperature was raised to 45 ° C., and a hexane solution of diethylaluminum chloride (0.2 mol) was added over 1 hour. 1 at 60 ℃ after adding everything
I stirred the time. Next, methylhydropolysiloxane (2
6 ml (0.1 gram atom of silicon) of a viscosity of about 30 centistokes at 5 ° C. was added, and the mixture was reacted under reflux for 1 hour. After cooling to 45 ° C., 23.3 g (0.15 mol) of i-butylaluminum dichloride diluted to 50 wt% with hexane
Was added over 2 hours. After adding everything, stirring was carried out at 70 ° C. for 1 hour. Bivalent Ti / total Ti was 24%. Subsequently, 11.7 g (0.05 mol) of iodine trichloride diluted to 5 wt% with 1,2-dichloroethane was added dropwise at 45 ° C, and
The temperature was raised to 0 ° C. and the reaction was carried out to obtain a solid catalyst component (A).
The titanium content of this solid catalyst component (A) was 7.6 wt%. The divalent titanium in this catalyst component is 13
It had decreased to%.

b) Polymerization The polymerization experiment of Example 1 was repeated, except that the above solid catalyst component was used. As a result, 216 g of polyethylene was obtained, the catalytic activity was 36000, and the ethane byproduct rate was 0.037%. The MI was 38 and the bulk density was 0.43 g / cm ³ .

Comparative Example 3 0.05 mol of the magnesium- and titanium-containing solution prepared in Example 4 in terms of Mg was added to a flask having an internal volume of 500 ml, and the temperature was raised to 45 ° C. to obtain an excess amount of diethylaluminum chloride (0.875 mol) in hexane. Was added over 1 hour. The subsequent adjustment was performed in the same manner as in Example 4. That is, 6 ml of methylhydropolysiloxane (0.1 gram atom of silicon) and 23.3 g (0.15 mol) of i-butylaluminum dichloride were used to obtain a solid component. The divalent Ti / total Ti in this solid component was 48%. Then, a solid catalyst component was obtained with 11.7 g (0.05 mol) of iodine trichloride. The titanium content of this solid catalyst component was 7.4 wt%. The divalent titanium in this catalyst component is 27%.
Had decreased to.

The results of polymerization with this solid catalyst component are shown in Table 1.

Example 5 An experiment was performed in the same manner as in Example 1 except that iodine trichloride was diluted to 2 wt% with hexane instead of being diluted with 1,2-dichloroethane.

As a result, 271 g of polyethylene was obtained, the catalytic activity was 45200, and the ethane byproduct rate was 0.010%. The MI was 42 and the bulk density was 0.42 g / cm ³ .

Examples 6 to 12 Experiments were performed in the same manner as in Example 1 except that various halogen compounds shown in Table 2 were used instead of using iodine trichloride in Example 1. The results are shown in Table 2.

Example 13 a) Preparation of solid catalyst component (A) 31.1 g (0.42 mol) of n-butanol was placed in an autoclave of 1.6 equipped with a stirrer, and 0.24 of iodine was added thereto.
g, 4.86 g (0.20 mol) of magnesium metal powder and 27.2 g (0.08 mol) of titanium tetrabutoxide were added, and 200 ml of hexane was further added, and then the temperature was raised to 80 ° C. under a nitrogen blanket while eliminating generated hydrogen gas. Stirred for 1 hour. Subsequently, the temperature was raised to 120 ° C. and the reaction was carried out for 1 hour. Then at 120 ℃ dimethyl polysiloxane (25 ℃
Viscosity of about 50 centistokes) at 153 g (0.2 gram atom of silicon) was pumped by nitrogen,
Reacted for hours. After the reaction, add 300 ml of hexane and 45
After cooling to [deg.] C, 186 g (1.2 mol) of i-butylaluminum dichloride diluted to 50 wt% with hexane was added over 3 hours. After adding everything, stirring was carried out at 60 ° C. for 1 hour. A small amount of this product was collected and the divalent titanium was measured, and it was less than 1%. Then 1.35 g of iodine trichloride diluted to 5 wt% with 1,2-dichloroethane
(5.8 mmol) was added dropwise at 45 ° C., and the temperature was raised to 70 ° C. for reaction to obtain a solid catalyst component (A). The titanium content of this solid catalyst component (A) is 8.5 wt% and the divalent Ti / total Ti is 1%.
Was less than.

b) Polymerization The polymerization experiment of Example 1 was repeated, except that 7 mg of the above solid component was used. As a result, 255 g of polyethylene was obtained, the catalytic activity was 36400 ethane, and the by-product rate was 0.012%.
Met. Also, the MI is 45 and the bulk density is 0.44 g / cm ^3.
Met.

Example 14 a) Preparation of solid catalyst component (A) In a flask in a container 1 equipped with a stirrer under a nitrogen atmosphere, 4.9 g (0.20 mol) of magnesium metal powder, 17 g (0.05 mol) of titanium tetrabutoxide and tetrachloride of tetrachloride were prepared. Zirconium 11.65
Add g (0.05mol) and heat up to 80 ℃, then 0.20g
64.1 g (0.80 mol) of n-butanol in which iodine was dissolved was added dropwise over 1 hour, and then heated to 120 ° C. for reaction. 200 ml of hexane was added to the reaction product thus obtained at room temperature, and then 300 g (1.2 mol) of ethylaluminum dichloride diluted to 50 wt% with hexane was added to the reaction product.
The mixture was added dropwise at 5 ° C over 2 hours. When a small amount of this product was collected, divalent Ti / total Ti was less than 1%. Then, 1.35 g (5.8 mmol) of iodine trichloride diluted to 5 wt% with 1,2-dichloroethane was added dropwise at 45 ° C. and the temperature was raised to 70 ° C. for reaction to obtain a solid catalyst component (A). The titanium content of this solid catalyst component (A) was 5.1 wt%.

b) Polymerization The inside of the electromagnetic stirring reactor made of stainless steel with an internal volume of 2 was sufficiently replaced with nitrogen, hexane 1.2 was charged, and the internal temperature was adjusted to 70 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B) and 18 mg of the above component (A) were sequentially added. 1kg / c in the reactor
After adjusting to m ² G, add 13.3 kg / cm ² of hydrogen to bring the total pressure to 20.
Polymerization was carried out for 1.5 hours while ethylene was continuously added so that the concentration became kg / cm ³ G. After the polymerization was completed, a small amount of the gas phase portion and the liquid phase portion were sampled and the amount of ethane produced as a by-product was measured. Further, polyethylene was taken out from the autoclave and separated from the solvent by filtration. As a result, the catalytic activity obtained from 218 g of polyethylene was 12100, and the ethane by-product rate was 0.007%. Also, MI is 0.05, HLMI
/ MI was 165 and the bulk density was 0.39 g / cm ³ .

Comparative Example 5 The same experiment as in Example 14 was carried out except that the catalyst component (A) was prepared in the method of Example 14 without using iodine trichloride. The amount of polyethylene obtained was 194 g, and the ethane by-product rate was 0.71%. Also, MI is 0.08, HLMI
/ MI was 140 and the bulk density was 0.37 g / cm ³ .

Example 15 a) Preparation of solid catalyst component (A) 2.4 g (0.10 mol) of magnesium metal powder and 13.6 g (0.04 mol) of titanium tetrabutoxide were added to a flask having a volume of 1 and equipped with a stirrer under a nitrogen atmosphere. , N-butanol in which 0.12 g of iodine was dissolved by heating to 80 ° C
15.6 g (0.21 mol) was added dropwise over 1 hour and then 120
The mixture was warmed to ℃ and reacted. 170 ml of hexane was added to the reaction product thus obtained at room temperature, and then 20.8 g (0.10 m) of phosphorus pentachloride diluted to 5% with 1,2-dichloroethane.
ol) was added dropwise at 45 ° C. over 2 hours. A small amount of this reaction product was sampled to measure divalent titanium.
Valence Ti / total Ti was 0%. Then 50 with hexane
Ethyl aluminum dichloride 23.3 diluted to wt%
g (0.15 mol) was added dropwise at 45 ° C. over 2 hours to prepare a solid catalyst component (A).

b) Polymerization The polymerization experiment of Example 1 was repeated, except that 7 mg of the above solid component was used. As a result, 254 g of polyethylene was obtained, the catalytic activity was 36300, and the ethane byproduct rate was 0.01.
It was 2%. Also, MI is 45 and bulk density is 0.41 g / c.
It was m ³ .

Example 16 a) Preparation of solid catalyst component (A) 2.4 g (0.10 mol) of metallic magnesium powder and 13.6 g (0.04 mol) of titanium tetrabutoxide were added to a flask having a volume of 1 and equipped with a stirrer under a nitrogen atmosphere. N-Butanol 1 in which 0.12 g of iodine was dissolved and heated to 80 ° C
5.6g (0.21mol) was added dropwise over 1 hour, then 120 ℃
The mixture was heated up to the reaction. 170 ml of hexane was added to the reaction product thus obtained at room temperature, and then 11.7 g (0.05 m of iodine trichloride diluted with 5% of 1,2-dichloroethane).
ol) was added dropwise at 45 ° C. over 1 hour. A small amount of this reaction product was sampled to measure divalent titanium.
Valence Ti / total Ti was 0%. Then 50 with hexane
Ethyl aluminum dichloride 62 diluted to wt%
g (0.40 mol) was added dropwise at 45 ° C. over 2 hours to prepare a solid catalyst component (A).

b) Polymerization The polymerization experiment of Example 1 was repeated, except that 7 mg of the above solid component was used. As a result, 248 g of polyethylene was obtained, the catalytic activity was 35400, and the by-product rate of ethane was 0.012.
%Met. Also, MI is 45 and bulk density is 0/42 g / cm.
^{Was 3} .

Example 17 Using the solid catalyst component (A) prepared in Example 1, multistage polymerization was carried out.

Two stainless steel electromagnetic stirring type reactors with an internal capacity of 5 were used, and one reactor was charged with 3 hexanes to adjust the internal temperature to 85 ° C, and then tri-i was used as the catalyst component (B).
-Butyl aluminum 1.7g (8.5mmol), solid catalyst component
(A) 180 mg was added. After adjusting the internal pressure of the reactor to 1 kg / cm ² G with nitrogen gas, a hydrogen partial pressure of 19.0 kg / cm ² was added, further total pressure 25 kg / cm ² so that the G continuously ethylene were added 65 minutes Polymerization was carried out to produce a low molecular weight polymer. A small amount of each of the gas phase portion and the liquid phase portion of this reactor was sampled, and the molecular weight of the polymer and the amount of ethane produced as a by-product were measured.

Hexane 3 was charged into the other reactor, and tri-i-
1.7 g (8.8 mmol) of butylaluminum and 90 mg of solid catalyst component (A) were added. After adjusting the internal pressure of the reactor to 1 kg / cm ² G with nitrogen gas, hydrogen partial pressure of 0.1 kg / cm ² was added, and ethylene was continuously added so that the total pressure became 4.0 kg / cm ² G. Polymerization was carried out for a minute to produce a high molecular weight polymer.

Next, the reaction mixture containing these polymers was pressure-fed to a stirring reactor having an internal volume of 10 through a connecting pipe. The internal temperature of the gas phase of this reactor replaced with nitrogen was 80 ° C, and the internal pressure was 1.0k.
g / cm ² G, hydrogen partial pressure 1.2 kg / cm ² G was added, and ethylene was continuously fed so that the total pressure became 5.2 kg / cm ² G, and polymerization was performed for 45 minutes to prepare a reaction mixture. It was filtered and dried.
The amount of the polymer obtained was 2430 g. The production amount in each stage was grasped by the ethylene flow rate, and the production ratio was 40 wt% for the low molecular weight polymer in the preceding stage, 40 wt% for the high molecular weight polymer and 20 wt% in the latter stage.

The by-product rate of ethane was 0.023%, which was very low. In addition, the polymer powder obtained is screw diameter 25 mm.
Pelletized with the extruder of
0.058, HLMI / MI 190, density 0.956g / cm ³
Met. In addition, when the pellets were formed into a film by a balance film forming machine, the fish eyes were less likely to occur, the film had a thickness of 30 μ, and the fish eyes having a diameter of 0.2 mm or more were about 2300 pieces / m ² , and were excellent. It became a film.

Example 18 Two-step polymerization was carried out using the solid catalyst component (A) prepared in Example 1.

The inside of the electromagnetic stirring reactor made of stainless steel with an internal volume of 10 was sufficiently replaced with nitrogen, and hexane 6.0 was charged.
The internal temperature was adjusted to 85 ° C. Then, 1.19 g (6.0 mmol) of tri-i-butylaluminum as the catalyst component (B) and 75 mg of the component (A) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, the hydrogen partial pressure was 16.0 k
Polymerization was carried out for 60 minutes while adding g / cm ² and continuously adding ethylene so that the total pressure was 20 kg / cm ² G to produce a low molecular weight polymer. A small amount of each of the gas phase portion and the liquid phase portion of this reactor was sampled, and the molecular weight of the polymer and the amount of ethane produced as a by-product were measured.

Next, the gas phase of this reactor was replaced with nitrogen, and the internal temperature was adjusted to 75
℃, the internal pressure was 1.0kg / cm ² G, hydrogen partial pressure 1.0kg / cm ² was added, and further ethylene was continuously fed so that the total pressure became 5.0kg / cm ² G, and polymerization was carried out for 45 minutes. Performed and the reaction mixture was filtered and dried. The amount of the polymer obtained was 2520 g.
The production amount in each stage was grasped by the ethylene flow rate, and the production ratio was 50 wt% for the low molecular weight polymer in the front stage and 50 wt% for the high molecular weight polymer in the rear stage.

The ethane by-product rate during polymerization was 0.004%, which was extremely low. Furthermore, pelletization was carried out by the same method as in Example 1, but the MI of this pellet was 0.061, the HLMI / MI was 190, and the density was 0.956 g / cm ³ . In addition, when the pellets were formed into a film by a balance film forming machine, the fish eyes were less likely to occur, and the film had a thickness of 30μ and the fish eyes with a diameter of 0.2 mm or more had about 2000.
A Ke / m ^2, and was a good film.

Example 19 In the method of Example 1, an experiment was conducted by using triethylaluminum in place of the component (B), tri-i-butylaluminum. That is, 7 mg of the solid catalyst component (A) prepared in Example 1 and 0.14 g of triethylaluminum (1.
Polymerization was carried out under the same conditions using (2 mmol).

As a result, 216 g of polyethylene was obtained, the catalytic activity was 30,100, and the ethane by-product rate was 0.039%. Also, MI is 42, HLMI / MI is 32, and bulk density is
It was 0.41 g / cm ³ .

Example 20 An experiment was performed in the same manner as in Example 1 except that a small amount of 1-butene was added during the polymerization.
That is, the solid catalyst component (A) and tri-i-butylaluminum prepared in Example 1 were used in the same manner as in Example 1, and 20 g of 1-butene was further used to carry out a polymerization experiment.

As a result, 235 g of polyethylene was obtained, the catalytic activity was 33600, and the ethane by-product rate was 0.011%.
The MI was 47, the HLMI / MI was 28, and the bulk density was 0.40 g / cm ³ .

Example 21 Polymerization was carried out in the gas phase using the solid catalyst component (A) prepared in Example 1. 50 g of polyethylene powder having an MI of 12 was charged into an electromagnetic stirring type reaction vessel made of stainless steel having an internal volume of 2 and dried at 70 ° C. for 2 hours, and then the internal temperature was adjusted to 60 ° C. Then, 0.46 g (2.4 mmol) of tri-i-butylaluminum as the catalyst component (B) and 25 mg of the component (A) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, 2 kg / cm ² of hydrogen was added, and ethylene was continuously added so that the total pressure became 5 kg / cm ² G, and polymerization was carried out for 1.5 hours. It was After the polymerization was completed, a small amount of the gas phase portion was collected and the amount of ethane produced as a by-product was measured. In addition, when polyethylene was taken out from the autoclave, 114 g
Was obtained, and the ethane by-product rate was 0.037%. The MI was 9 and the HLMI / MI was 32.

Comparative Example 6 The same experiment as in Example 21 was carried out except that 20 mg of the solid catalyst prepared in Comparative Example 1 was used as the component (A) in the method of Example 21. 103 g of polyethylene obtained
The ethane by-product rate was 0.267%. MI is 1
1, the HLMI / MI was 32.

[Brief description of drawings]

FIG. 1 is a flowchart showing a catalyst preparation process according to the present invention.

Claims (2)

[Claims] 1. A process for producing polyethylene in which ethylene or ethylene and an α-olefin are polymerized at a reaction temperature lower than the melting point of the polymer in the presence of a Ziegler type catalyst having high activity and hydrogen, the catalyst comprising: A) (i) a product obtained by reacting titanium tetraalkoxide with a reactant comprising metallic magnesium and at least one aliphatic alcohol, (ii) at least one organoaluminum dihalide and (iii) halogen , Interhalogen compounds and tin, lead,
Solid catalyst component (A) obtained by reacting at least one halogen-containing compound selected from the group of phosphorus, antimony and sulfur halogen compounds
And (B) an organoaluminum compound catalyst component (B). 2. A reaction product of (i) or a reaction product of the reaction product of (i) with a compound of (ii), before reacting the halogen-containing compound of (iii), The manufacturing method according to claim 1, which contains less than 30% of divalent titanium when expressed as a percentage of total titanium.