JPH05255440A - Production of ethylenic polymer - Google Patents

Abstract

PURPOSE:To obtain the subject polymer excellent in below moldability and in the balance between rigidity and environmental stress cracking resistance by performing an excellent three-stage polymerization in the presence of a specific catalyst. CONSTITUTION:When ethylene or its mixture with an alpha-olefin is polymerized or copolymerized in the presence of a catalyst comprising (A) a solid catalyst component containing a magnesium alkoxide, a Ti compound and an aluminum halide, (B) an organic Al compound and (C) an electron donor, the polymerization or copolymerization reaction is performed by the first step reaction under conditions comprising an eta1 of 7-20dl/p, a P1 of 10-20wt.% and an alpha1 of 0-5%, by the second step reaction under conditions comprising a eta2 of 0.5-1.5dl/g, a (p2+p3) of 80-90% and an alpha2 of 0-5% and satisfying the inequality, and subsequently by the third step reaction under conditions comprising an eta3 of 0.5-1.5dl/g and an alpha3 of 0-5%, wherein the P1, P2 and P3 are the amounts of the polymers produced in the first, second and third steps on the basis of the whole amount of the polymers, eta1, eta2 and eta3 are the intrinsic viscosities of the polymers, and the alpha1, alpha2 and alpha3 are the amounts of the alpha-olefin units in the polymers, respectively.

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 an ethylene polymer, which is preferably used as a molding material for hollow molded articles, by a multistage polymerization method.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
A two-step polymerization method is known as a means for producing polyethylene for blow molding having a wide molecular weight distribution. Polyethylene obtained by this two-step polymerization method has a better balance of rigidity and ESCR (environmental stress cracking) than polyethylene obtained by the one-step polymerization method, but the fusion strength of the pinch-off part of the hollow molded product Therefore, the tolerance of the pinch-off shape of the mold is narrow, the occurrence rate of product defects is high, the die swell is small, and the requirements are not sufficiently satisfied.

On the other hand, a three-step polymerization method has been proposed as a means for improving the above-mentioned drawbacks of the two-step polymerization method (Japanese Examined Patent Publication No. 59-10724). However, although the polyethylene produced by the three-stage polymerization method improves the die swell,
The pinch-off fusion property is not sufficiently improved, and the rigidity and E
There is a problem that the balance with the SCR becomes worse.

On the other hand, various attempts have been made to improve the catalyst for the purpose of obtaining polyethylene having good hollow moldability. For example, a method of polymerizing ethylene or copolymerizing ethylene with another α-olefin by using a catalyst system composed of a combination of an organomagnesium compound, a titanium compound, a zirconium compound and an aluminum halide compound has been proposed (special feature: Koho 55-8083). This catalyst system is capable of adjusting the molecular weight distribution of the polymer to be produced over a wide range, and is capable of producing polyethylene having improved pinch-off fusion strength and die swell. But,
The polyethylene obtained using the above catalyst system has rigidity and E
The balance with SCR is insufficient, and therefore it is not always satisfactory as a molding material for small and medium-sized hollow molded products.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a method for producing an ethylene polymer having excellent hollow moldability and excellent balance between rigidity and ESCR. The purpose is to

[0006]

In order to achieve the above-mentioned object, the present invention provides a homopolymerization of ethylene or ethylene and other α.
-Solid catalyst component containing the following (A) component, (B) component and (C) component (A) (a) magnesium alkoxide, (b) titanium compound and (c) aluminum halide for copolymerization with olefin (B) Organoaluminum compound (C) Using a catalyst composed of an electron donor, the following first step, second step and third step
Provided is a method for producing an ethylene-based polymer, which is characterized by carrying out by a multistage polymerization method comprising steps.

First step: a step of polymerizing so as to satisfy the following formulas I, II and III: 7 dl / g ≦ η1 ≦ 20 dl / g ... I 10 wt% ≦ P1 ≦ 20 wt%… II 0 wt% ≦ α1 ≦ 10% by weight ... III Second step: step of polymerizing so as to satisfy the following formulas IV, V, VI and VII 0.5 dl / g ≦ η2 ≦ 1.5 dl / g IV IV 0.5 dl / g ≦ (η2 + η3) / 2 ≤ 1.0 dl / g V 80 wt% ≤ P2 + P3 ≤ 90 wt% ... VI 0 wt% ≤ α2 ≤ 5 wt% VII Third step: to satisfy the following formulas VIII and IX and the above formulas V and VI 0.5 dl / g ≦ η3 ≦ 1.5 dl / g ... VIII 0% by weight ≦ α3 ≦ 5% by weight IX

[However, in the above formulas I to IX, η1: the intrinsic viscosity of the polymer formed in the first step (dl /
g) η2: intrinsic viscosity of polymer produced in the second step (dl /
g) η3: intrinsic viscosity of polymer produced in the third step (dl /
g) P1: Proportion (% by weight) of the polymer produced in the first step with respect to the total amount P2: Proportion (% by weight) of the polymer produced in the second step with respect to the total amount P3: Produced in the third step with respect to the total amount Ratio of polymer (% by weight) α1: Ratio of α-olefin units other than ethylene in the polymer produced in the first step (% by weight) α2: α-olefin other than ethylene in polymer produced in the second step Unit ratio (wt%) α3: Ratio of α-olefin units other than ethylene in the polymer produced in the third step (wt%)]

Here, the above η1 to 3, P1 to 3 and α1 to
3 is a numerical value for the polymer produced in each step. η1 to 3 can be obtained by the following method. η1 is a value obtained by sampling the polymer at the end of the first step and measuring the [η] thereof as it is.
η2 is obtained as follows. η2 = (P1 + P2) ηII / P2-P1 · η1 / P2 (ηII is the intrinsic viscosity of the polymer at the end of the second step) η3 is determined as follows. η3 = 100 · ηIII / P3- (P1 + P2) ηII / P
3 (ηIII is the intrinsic viscosity of the polymer at the end of the third step)

The present invention will be described in more detail below. In the catalyst used in the present invention, as the component (A), (a)
A solid catalyst component composed of magnesium alkoxide, (b) titanium compound and (c) aluminum halide is used.

As the magnesium alkoxide (a) used for preparing the solid catalyst component (A), a compound represented by the following general formula (a) is preferably used. Mg (OR ¹ ) _m X ¹ _2-m (i) (In the formula, R ¹ is a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, X ¹ is a halogen atom, m is a number of 1 to 2, and when m is 2, R ¹ may be the same or different.

Examples of the magnesium alkoxide represented by the general formula (a) include methoxymagnesium chloride, ethoxymagnesium chloride, ethoxymagnesium bromide, ethoxymagnesium iodide and n-.
Alkoxy magnesium halides such as propoxy magnesium chloride, isopropoxy magnesium chloride, n-butoxy magnesium chloride, sec-butoxy magnesium chloride, isobutoxy magnesium chloride, t-butoxy magnesium chloride, pentyloxy magnesium chloride, hexyloxy magnesium chloride, dimethoxy magnesium, Diethoxymagnesium, di-n-propoxymagnesium, diisopropoxymagnesium, dialkoxymagnesium such as dibutoxymagnesium, diaryrloxymagnesium such as diphenoxymagnesium, diaulkyroxymagnesium such as dibenzyloxymagnesium, ethoxyphenoxy Al, such as magnesium and butoxyphenoxy magnesium Such as carboxymethyl aryloxy magnesium. Among these magnesium alkoxides, those having a lower alkoxy group, particularly dimethoxymagnesium and diethoxymagnesium are preferable. In addition, these magnesium alkoxides may be used alone or in combination of two or more kinds.

Further, instead of magnesium alkoxide, a reaction product of metallic magnesium, alcohol and halogen can be used. The shape of the metal magnesium used at this time is not particularly limited, and any shape of metal magnesium, for example, granular, ribbon-like, powder-like or the like can be used. In addition, the surface condition of metallic magnesium is not particularly limited,
It is advantageous that the surface is not coated with magnesium oxide or the like.

The type of alcohol is not particularly limited, but a lower alcohol having 1 to 6 carbon atoms is preferable, and ethanol is particularly preferable because it provides a solid catalyst component that improves the catalytic performance. The purity and the water content of the alcohol are not particularly limited, but when an alcohol having a high water content is used, magnesium hydroxide is formed on the surface of the metal magnesium, so that the water content is 1% by weight or less, particularly 2000 pp.
It is preferable to use an alcohol of m or less, and the smaller the water content, the more advantageous. Further, as the halogen, bromine or iodine is preferable. The form of halogen is not particularly limited, and it may be dissolved in an alcohol solvent and used as a solution.

The amount of alcohol used is usually 2 to 100 mol, preferably 5 to 50 mol per mol of magnesium metal.
It is selected in the molar range. If the amount of alcohol is too large, it tends to be difficult to obtain a magnesium compound having good morphology, and if it is too small, the reaction with metallic magnesium may not proceed smoothly. Further, halogen is usually 0.0 per mol of magnesium metal.
It is used in a proportion of 001 g atom or more, preferably 0.0005 g atom or more, and more preferably 0.001 g atom or more. When the amount of halogen used is less than 0.0001 g atom, the amount of supported titanium, the catalytic activity, and the morphology of the produced polymer are lowered when the obtained magnesium compound is used without pulverization. Therefore, it is not preferable since the obtained magnesium compound must be pulverized. Further, the upper limit of the amount of halogen used is not particularly limited, and may be appropriately selected within a range in which a desired magnesium compound is obtained. Further, the particle size of the obtained magnesium compound can be arbitrarily controlled by appropriately selecting the amount of halogen used.

The reaction of magnesium metal, alcohol and halogen can be carried out by a known method. For example, metallic magnesium, alcohol, and halogen are usually added under reflux until hydrogen gas is no longer generated.
The desired magnesium compound is obtained by reacting for about 30 hours. Specifically, when iodine is used as the halogen, solid iodine is added to a mixture of metal magnesium and alcohol, and then heated and refluxed, an alcohol containing iodine in the mixture of metal magnesium and alcohol. A method of heating and refluxing after dropping the solution, a method of dropping an alcohol solution containing iodine while heating a mixture of magnesium metal and alcohol, and the like can be used. In any of the methods, it is preferable to use an inert organic solvent such as a saturated hydrocarbon such as n-hexane under an inert gas atmosphere such as nitrogen gas or argon gas in some cases.

Regarding the addition of magnesium metal and alcohol, it is not always necessary to add the whole amount to the reaction tank from the beginning, but it is also possible to add them separately. For example, there is a method in which the entire amount of alcohol is charged from the beginning and metallic magnesium is charged in several times. This method can prevent the temporary generation of a large amount of generated hydrogen gas, and is extremely desirable in terms of safety,
In addition, it is possible to reduce the size of the reaction tank, and it is possible to prevent the entrainment of alcohol and halogen caused by the temporary large generation of hydrogen gas. The number of divisions may be determined in consideration of the scale of the reaction tank and is not particularly limited, but in consideration of the complexity of the operation, it is usually selected in the range of 5 to 10 times.

The reaction itself may be either a batch type or a continuous type. As a modified method, a small amount of metallic magnesium is first added to the alcohol which is entirely charged from the beginning, and the product produced by the reaction is put into another tank. After separating and removing,
It is also possible to repeat the operation of adding a small amount of metallic magnesium again. The magnesium compound thus obtained can be used in the next step without pulverization or classification operation for making the particle size uniform.

As the titanium compound (b) used for preparing the solid catalyst component (A), a compound represented by the following general formula (II) is preferably used. Ti (OR ² ) _n X ² _4-n (B) (wherein R ² is a hydrocarbon group, X ² is a halogen atom, and n is a number from 0 to 4)

R ² in the general formula (b) is a hydrocarbon group, which may be a saturated group or an unsaturated group, and may be a linear or branched one, or a cyclic one. It may be present, and may be one having a hetero atom such as sulfur, nitrogen, oxygen, silicon or phosphorus, but preferable hydrocarbon groups are alkyl groups having 1 to 20 carbon atoms, alkenyl groups, cyclo Examples thereof include an alkyl group, a cycloalkenyl group, an aryl group and an aralkyl group. Specific examples of R ² include methyl group, ethyl group, n-
Propyl group, isopropyl group, n-butyl group, sec-
Butyl, isobutyl, ventil, hexyl, heptyl, octyl, decyl, octadecyl, allyl, butenyl, cyclopentyl, cyclohexyl, cyclohexenyl, phenyl, tolyl, benzyl, phenethyl Groups and the like.

X ² in the general formula (b) is a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Of these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable. Is.

Typical examples of the titanium compound represented by the general formula (b) include titanium tetrachloride and titanium tetrabromide when n is 0, and ethoxytrichlorotitanium when n is 1. n-propoxytrichlorotitanium, n
-Butoxytrichlorotitanium, etc., when n is 2, diethoxydichlorotitanium, di-n-propoxydichlorotitanium, di-n-butoxydichlorotitanium, etc., and when n is 3, triethoxymonochlorotitanium, tri-n -Propoxy monochloro titanium, tri-n-butoxy monochloro titanium, etc., when n is 4, tetraethoxy titanium,
Examples thereof include tetra-n-propoxy titanium, tetraisopropoxy titanium, and tetra-n-butoxy titanium.
Among these, those having a lower alkoxy group, particularly tetra-n-butoxytitanium, are preferable. These titanium compounds may be used alone or in combination of two or more.

As the aluminum halide (c) used for preparing the solid catalyst component (A), a compound represented by the following general formula (C) is preferably used. AlR ³ _k X ³ _3-k (C) (wherein R ³ is a hydrocarbon group, X ³ is a halogen atom, and k is a number of 1 to 2)

R ³ in the general formula (c) is a hydrocarbon group, which may be a saturated group or an unsaturated group, and may be a linear group, a branched group, or a cyclic group. It may be present, and may be one having a hetero atom such as sulfur, nitrogen, oxygen, silicon or phosphorus, but preferable hydrocarbon groups are alkyl groups having 1 to 20 carbon atoms, alkenyl groups, cyclo Examples thereof include an alkyl group, a cycloalkenyl group, an aryl group, and an aralkyl group. Specific examples of R ³ are the same as those exemplified for R ² in the general formula (b). Further, X ³ in the general formula (C) is a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable.

Typical examples of the organic aluminum halide represented by the general formula (C) include methylaluminum dichloride, ethylaluminum dichloride, n-propylaluminium dichloride, isopropylaluminum dichloride, and n when k is 1. -Butylaluminum dichloride, isobutylaluminum dichloride, etc., when k is 2, dimethylaluminum monochloride, diethylaluminum monochloride, di-n
-Propyl aluminum monochloride, diisopropyl aluminum monochloride, di-n-butyl aluminum monochloride, diisobutyl aluminum monochloride and the like. Of these, lower alkyl aluminum halides, particularly ethyl aluminum dichloride, are preferred. These organic aluminum halides may be used alone or in combination of two or more.

The solid catalyst component used as the component (A) of the catalyst of the present invention can be prepared by bringing the above-mentioned (a) magnesium alkoxide, (b) titanium compound and (c) aluminum halide into contact with each other. In this case, there is no particular limitation on the quantitative relationship among the components (a), (b) and (c), but the molar ratio of aluminum halide / magnesium alkoxide is 1
To 100, preferably 3 to 40, and the molar ratio of magnesium alkoxide / titanium compound is 1 to 1
It is desirable to prepare it in the range of 00, preferably 2 to 40.

In preparing the solid catalyst component (A), a zirconium compound (d) may be added as a transition metal compound, if desired. Examples of the zirconium compound include zirconium tetrachloride, monoethoxytrichlorozirconium, mono-n-propoxytrichlorozirconium, mono-n-butoxytrichlorozirconium, diethoxydichlorozirconium, di-n-propoxydichlorozirconium and di-n-butoxy. Examples thereof include dichlorozirconium, triethoxy monochloro zirconium, tri-n-propoxy monochloro zirconium, tri-n-butoxy monochloro zirconium, tetraethoxy zirconium, tetra-n-propoxy zirconium, and tetra-n-butoxy zirconium. These zirconium compounds may be used alone or in combination of two or more. In this case, the zirconium / titanium atomic ratio is preferably in the range of 0.5 to 20.

The order of contacting each of the above-mentioned components is not particularly limited, but a method of sequentially contacting the components (a), (b), and optionally (d) and (c), or ( a) component, (d) component used as desired,
A method of sequentially contacting the component (b) and the component (c) is preferably used. This contact is usually performed in an inert solvent. Examples of the inert solvent include pentane,
One or more hydrocarbon solvents selected from hexane, cyclohexane, heptane and the like are preferably used. Further, the aluminum halide of the component (c) is
While maintaining the system temperature in the range of 10 to 50 ° C., it is preferable to add gradually so that the reaction proceeds uniformly.

In this way, the solid catalyst component of the component (A) in the present invention is obtained in a slurry state in the reaction product liquid. This slurry-like reaction product liquid may be used as it is as a catalyst component for ethylene polymerization, or after the solid catalyst component is separated and recovered from the reaction product liquid, washed as needed and used as a catalyst component for ethylene polymerization. May be.
As the separation method at this time, a known method such as a centrifugation method or a filtration method can be used, and the washing is
It can be carried out using an inert hydrocarbon solvent such as pentane, hexane, cyclohexane or heptane.

In the present invention, the organoaluminum compound used as the component (B) is, for example, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylaluminum monochloride, diisopropylaluminium monochloride, diisobutylaluminum monochloride, Dioctyl aluminum monochloride, diethyl aluminum monoethoxide, dimethyl aluminum monoethoxide, diethyl aluminum monobutoxide,
Diethyl aluminum monophenoxide, ethyl aluminum dichloride, isopropyl aluminum dichloride, methyl aluminum sesquichloride, ethyl aluminum sesquichloride and the like can be mentioned. These compounds may be used alone or in combination of two or more.

In the present invention, examples of the electron donor used as the component (C) include carboxylic acid esters,
Esters such as carbonic acid ester and orthoester, silanes such as alkoxysilane and aryloxysilane, ethers, ketones, acid anhydrides, acid halides,
Oxygen-containing compounds such as acid amides and phosphite esters,
Examples thereof include nitrogen-containing compounds such as tertiary amines and nitriles, and among these, ethers, particularly aromatic alkoxy compounds are preferable.

Specific examples of the aromatic alkoxy compound include m-methoxytoluene, o-methoxyphenol, m-methoxyphenol, 2-methoxy-4-methylphenol, vinylanisole, p- (1-propenyl) anisole, p-allylanisole, 1,3-bis (p-methoxyphenyl) -1-pentene, 5-allyl-2-methoxyphenol, 4-allyl-2-methoxyphenol, 4-hydroxy-3-methoxybenzyl alcohol, methoxybenzyl Alcohols, monoalkoxy compounds such as nitroanisole and nitrophenetole, o-dimethoxybenzene, m-dimethoxybenzene, p-dimethoxybenzene, 3,4-dimethoxytoluene, 2,6-dimethoxyphenol, 1-allyl-
Dialkoxy compounds such as 3,4-dimethoxybenzene and 1,3,5-trimethoxybenzene, 5-allyl-
1,2,3-trimethoxybenzene, 1,2,3-trimethoxy-5- (1-propenyl) benzene, 1,2,
4-trimethoxy-5- (1-propenyl) benzene,
Examples thereof include trialkoxy compounds such as 1,2,3-trimethoxybenzene and 1,2,4-trimethoxybenzene. Among these, dialkoxy compounds and trialkoxy compounds are preferable. These alkoxy group-containing aromatic compounds may be used alone,
You may use it in combination of 2 or more type.

The polymerization catalyst of the present invention contains the solid catalyst component (A), the organoaluminum compound (B), and the electron donor (C) prepared as described above. However, the order of addition of each of these components is not particularly limited, and the components (A), (B) and (C) may be contacted at the same time, or the components (B) and (C) may be contacted. May be brought into contact with the component (A), or the components (A) and (C) may be brought into contact with each other and then brought into contact with the component (B). In preparing the catalyst, the ratio of aluminum atoms to titanium atoms in the solid catalyst component is usually 1 to 1000 in atomic ratio.
In particular, it is preferable to prepare it so as to be 10 to 200.
The ratio of the (A) solid catalyst component to the (C) electron donor used is 7 mol times or less, preferably 1 to 6 mol times, of the titanium atom in the solid catalyst component. , And more preferably, it can be used in a ratio of 1 to 3 times by mole.

In the method of the present invention, a predetermined amount of each of the solid catalyst component (A), the organoaluminum compound (B) and the electron donor (C) is preferably added in an inert solvent such as pentane, hexane, cyclohexane or heptane. In addition to a hydrocarbon solvent such as the above, the desired ethylene-based polymer can be obtained by carrying out the polymerization in the order of the following first step, second step and third step in the presence of this catalyst.

Next, each step will be described. The first step η1 is 7 to 20 dl / g, preferably 10 to 15 dl / g.
g, P1 is 10 to 20% by weight, preferably 12 to 18% by weight, α1 is 0 to 10% by weight, preferably 0 to 5% by weight
Polymerization is performed so that When η1 is less than 7 dl / g, the pinch-off fusion bondability and toughness of the polymer become insufficient,
When it exceeds 20 dl / g, the impact resistance decreases and fish eyes are likely to occur. If P1 is less than 10% by weight, the pinch-off fusion bondability becomes insufficient and the ESC
When R is reduced and exceeds 20% by weight, hollow moldability is reduced. When α1 exceeds 10% by weight, soluble components increase,
Continuous drivability deteriorates.

Second and Third Steps In the second and third steps, both η2 and η3 are 0.5 to 1.5 dl / g, preferably 0.7 to 1.
2 dl / g, the average value of η2 and η3 is 0.5 to 1.0 d
1 / g, preferably 0.7-0.9 dl / g, P2 and P
Polymerization is carried out such that the sum of 3 and 3 is 80 to 90% by weight, preferably 82 to 88% by weight, and α2 and α3 are both 0 to 5% by weight, preferably 0 to 1% by weight. When η2 and η3 are less than 0.5 dl / g, the soluble component increases and continuous operability deteriorates, and when it exceeds 1.5 dl / g, fluidity and rigidity decrease. When (η2 + η3) / 2 is less than 0.5 dl / g, the soluble component increases and continuous operability deteriorates,
If it exceeds 1.0 dl / g, the fluidity and rigidity deteriorate. P
When 2 + P3 is less than 80% by weight, the hollow moldability is deteriorated, and when it exceeds 90% by weight, the pinch-off fusion bondability becomes insufficient. If α2 and α3 exceed 5% by weight, the rigidity cannot be secured.

In the present invention, homopolymerization of ethylene or copolymerization of ethylene with other α-olefin is carried out by the above multistage polymerization. In this case, the type of α-olefin other than ethylene is not limited, but propylene, butene-
One or two or more of 1, pentene-1, octene-1,4-methylpentene-1, vinylcyclohexane and the like can be preferably used.

The polymerization method is not particularly limited, and the solution polymerization method,
Any method such as a suspension polymerization method and a gas phase polymerization method can be adopted. Further, the multistage polymerization of the present invention may be carried out continuously or batchwise. The molecular weight of the product in each step can be adjusted by adjusting the polymerization temperature, the catalyst concentration, the ratio of the catalyst and the monomer, the hydrogen concentration, etc., but the adjustment of the hydrogen concentration is particularly effective. Target. Further, the intrinsic viscosity of the final product (product in the third step) in the present invention is 2.0 to 3.
5 dl / g, especially 2.3 to 3.2 dl / g, density of 0.
955 to 0.970 g / cm ³ , especially 0.960 to 0.
966 g / cm ³ , and melt index (MI) of 0.
It is preferable to set 1 to 1.0 g / 10 minutes.

[0039]

EXAMPLES Next, the present invention will be specifically shown by Examples and Comparative Examples, but the present invention is not limited to the following Examples. Example 1 (1) Preparation of solid catalyst component 10 g of Mg (OEt) _{2 having} an average particle diameter of 12 μm was stirred.
50 ml of hexane in which 6.5 mmol of tetrabutoxyzirconium and 6.5 mmol of tetrabutoxytitanium were dissolved in 150 ml of hexane slurry containing 20 ° C.
After adding dropwise over 15 minutes at
92 ml of 50 wt% hexane diluted with Cl ₂ was added dropwise at 35 ° C. over 120 minutes. Then, the mixture was reacted for 120 minutes under reflux. Next, it was washed with dry hexane until chlorine was not detected in the liquid, and the total volume was adjusted to 500 ml with hexane to obtain a solid catalyst component.

(2) Production of ethylene copolymer 3 liters of n-hexane was added to an autoclave with a stirrer having a capacity of 7 liters, which was sufficiently replaced with nitrogen, and the temperature was 60 ° C.
After the temperature was raised to 0.75, 0.75 kg / cm ² · G of ethylene was introduced, and 13.3 g of butene-1 was charged. Then
Titanium 0.10 prepared in (1) above in an autoclave
After adding a solid catalyst component containing mmol, 3.0 mmol triisobutylaluminum and 0.15 mmol 1-allyl-3,4-dimethoxybenzene as an electron donor, the total pressure was 2.0 kg / cm ² · G. While supplying ethylene so as to maintain the above, 15.0% by weight of the total polymerization amount was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1 were removed from the autoclave. Then, put it in the autoclave.
-Add 2 liters of hexane and raise the temperature to 80 ° C, hydrogen 5.0 kg / cm ² · G, ethylene 1.45 kg / cm ² ·
After introducing G, while feeding ethylene so as to maintain the total pressure at 9.5 kg / cm ² · G, the total polymerization amount of 42.5
Weight percent was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and hydrogen gas were removed from the autoclave. Finally, the autoclave was heated to 85 ° C., after introducing the hydrogen 4.0kg / cm ² · G, and ethylene 2.2kg / cm ² · G, to hold the total pressure 8.5kg / cm ² · G While feeding ethylene in this manner, 42.5 wt% of the total amount of polymerization was polymerized to obtain an ethylene-based copolymer.

Example 2 3 liters of n-hexane was added to the same autoclave as in Example 1 and the temperature was raised to 60 ° C., then 0.8 kg of ethylene was added.
/ Cm ² · G was introduced, and 13.4 g of butene-1 was further charged. Then, titanium 0.
Solid catalyst component containing 10 mmol, 3.0 mmol triisobutylaluminum and 1-as electron donor
After adding 0.15 mmol of allyl-3,4-dimethoxybenzene, 15% by weight of the total polymerization amount was polymerized while feeding ethylene so as to maintain the total pressure at 2.0 kg / cm ² · G. .. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1 were removed from the autoclave. Then, put it in the autoclave.
-Add 2 liters of hexane, raise the temperature to 80 ° C, and add hydrogen 5.5 kg / cm ² · G and ethylene 1.5 kg / cm ² ·.
After introducing G, while feeding ethylene so as to maintain the total pressure at 9.0 kg / cm ² · G, the total polymerization amount of 42.5
Weight percent was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and hydrogen gas were removed from the autoclave. Finally, the autoclave was heated to 80 ° C., hydrogen of 6.0 kg / cm ² · G and ethylene of 2.1 kg / cm ² · G were introduced, and then the total pressure was maintained at 9.5 kg / cm ² · G. While feeding ethylene in this manner, 42.5 wt% of the total amount of polymerization was polymerized to obtain an ethylene-based copolymer.

Example 3 To the same autoclave as in Example 1, 3 liters of n-hexane was added, and the temperature was raised to 70 ° C., after which 0.75 k of ethylene was added.
g / cm ² · G was introduced, and 8.2 g of butene-1 was further charged. Then, titanium 0.
Solid catalyst component containing 10 mmol, 3.0 mmol triisobutylaluminum and 1-as electron donor
After adding 0.15 mmol of allyl-3,4-dimethoxybenzene, 15% by weight of the total polymerization amount was polymerized while feeding ethylene so as to maintain the total pressure at 2.0 kg / cm ² · G. .. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1 were removed from the autoclave. Then, put it in the autoclave.
-Add 2 liters of hexane and raise the temperature to 80 ° C, hydrogen 4.5 kg / cm ² · G and ethylene 1.5 kg / cm ² ·
After introducing G, while feeding ethylene so as to maintain the total pressure at 8.0 kg / cm ² · G, the total polymerization amount of 42.5
Weight percent was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and hydrogen gas were removed from the autoclave. Finally, the autoclave was heated to 90 ° C., after introducing the hydrogen 4.0kg / cm ² · G, and ethylene 2.2kg / cm ² · G, to hold the total pressure 9.2kg / cm ² · G While feeding ethylene in this manner, 42.5 wt% of the total amount of polymerization was polymerized to obtain an ethylene-based copolymer.

Comparative Example 1 3 liters of n-hexane was added to an autoclave with a stirrer having a capacity of 7 liters, which was sufficiently replaced with nitrogen, and the mixture was heated to 45 ° C.
After the temperature was raised to 0.3, 0.35 kg / cm ² · G of ethylene was introduced, and 13.3 g of butene-1 was charged. Then
The titanium prepared in Example 1 (1) was added to an autoclave.
After adding the solid catalyst component containing 10 mmol and 3.0 mmol triisobutylaluminum, the total pressure is 1.
While supplying ethylene so as to maintain 5 kg / cm ² · G, 15.0% by weight of the total amount of polymerization was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1 were removed from the autoclave. Next, 2 liters of n-hexane was added to the autoclave, the temperature was raised to 80 ° C., and hydrogen of 5.5 kg / cm ² ·
After introducing G and ethylene 0.9 kg / cm ² · G, 42.5 wt% of the total polymerization amount was polymerized while feeding ethylene so as to maintain the total pressure at 8.0 kg / cm ² · G. It was
Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and hydrogen gas were removed from the autoclave. Finally, the temperature of the autoclave was raised to 85 ° C, hydrogen 4.0 kg / cm ² · G and ethylene 1.6 kg.
/ Cm ² · G is introduced, the total pressure is 8.0 kg / cm ² · G
While feeding ethylene so as to keep the content at 4%, 42.5% by weight of the total polymerization amount was polymerized to obtain an ethylene-based copolymer.

Comparative Example 2 3 liters of n-hexane was added to the same autoclave as in Example 1 and the temperature was raised to 60 ° C., after which 0.75 k of ethylene was added.
g / cm ² · G was introduced and 5.5 g of butene-1 was charged. Then, in the autoclave, a solid catalyst component containing 0.10 mmol of titanium prepared in Example 1 (1), 3.0 mmol of triisobutylaluminum, and 0.15 of 1-allyl-3,4-dimethoxybenzene as an electron donor. After adding millimolar, total pressure is 2.0 kg / c
While supplying ethylene so as to maintain m ² · G, 15.0 wt% of the total amount of polymerization was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1 were removed from the autoclave. Next, add 2 liters of n-hexane to the autoclave,
After raising the temperature to 80 ° C. and introducing hydrogen 5.5 kg / cm ² · G and ethylene 1.2 kg / cm ² · G, the total pressure is 9.2 kg.
/ Cm ² · G while supplying ethylene so as to maintain
42.5% by weight of the total amount of polymerization was polymerized. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and hydrogen gas were removed from the autoclave.
Finally, the temperature of the autoclave was raised to 85 ° C. and hydrogen was adjusted to 6.0.
After introducing kg / cm ² · G, and ethylene 2.5kg / cm ² · G, while supplying ethylene to keep the total pressure at 9.8kg / cm ² · G, 42.5 of the total polymerization amount weight%
Was polymerized to obtain an ethylene-based copolymer.

Comparative Example 3 3 liters of n-hexane was added to the same autoclave as in Example 1 and the temperature was raised to 60 ° C., after which 0.75 k of ethylene was added.
g / cm ² · G was introduced, and butene-1 was added to 13.3 g.
I prepared it. Then, a solid catalyst component containing 0.10 mmol of titanium prepared in Example 1 (1), 3.0 mmol of triisobutylaluminum, and 0.15 mmol of 1-allyl-3,4-dimethoxybenzene as an electron donor. After the addition, 15% by weight of the total polymerization amount was polymerized while feeding ethylene so as to maintain the total pressure at 2.0 kg / cm ² · G. Then, the inside of the autoclave was sufficiently replaced with nitrogen, and the remaining ethylene gas and butene-1
Was removed from the autoclave. Next, 2 liters of n-hexane was added to the autoclave, the temperature was raised to 80 ° C., and 4.0 kg / cm ² · G hydrogen and 1.5 kg / cm ethylene.
After introduction of ² · G, while supplying ethylene to keep the total pressure at 8.0kg / cm ² · G, the total polymerization amount 42.
5% by weight was polymerized. Finally, autoclave 80
℃ heated, after hydrogen was introduced 2.5kg / cm ² · G, and ethylene 2.3kg / cm ² · G, 8.0kg the total pressure
/ Cm ² · G while supplying ethylene so as to maintain
An ethylene copolymer was obtained by polymerizing 42.5% by weight of the total amount of polymerization.

Table 1 shows the intrinsic viscosity, the polymerization rate, the proportion of α-olefin units other than ethylene, the density, the intrinsic viscosity and the ESCR of the obtained ethylene copolymer in each of the above Examples and Comparative Examples. Show. The physical properties shown in Table 1 were determined as follows. (1) Intrinsic viscosity: measured in decalin at 135 ° C. (2) Density: Obtained according to JIS K-7112. (3) ESCR: Obtained in accordance with ASTM D-1693. In this case, the F50 value was obtained at a temperature of 50 ° C. using a 10 wt% aqueous solution of Nissan Nonion as a surfactant.

[0047]

[Table 1]

[0048]

As described above, according to the present invention,
It is possible to obtain an ethylene polymer having excellent hollow moldability and having a good balance between rigidity and ESCR.

Claims (2)

[Claims] 1. A homopolymerization of ethylene or a copolymerization of ethylene with another α-olefin is carried out by the following components (A) and (B).
Component and (C) Component (A) Solid catalyst component containing (a) magnesium alkoxide, (b) titanium compound and (c) aluminum halide (B) Organoaluminum compound (C) Using catalyst composed of electron donor , The following first step, second step and third step
Step 1st step: Step of polymerizing so as to satisfy the following formulas I, II and III 7 dl / g ≦ η1 ≦ 20 dl / g ... I 10 wt% ≦ P1 ≦ 20 wt%… II 0 wt% ≦ α1 ≦ 10 wt % ... III Second step: step of polymerizing so as to satisfy the following formulas IV, V, VI and VII 0.5 dl / g ≦ η2 ≦ 1.5 dl / g ... IV 0.5 dl / g ≦ (η2 + η3) / 2 ≦ 1.0 dl / g V 80% by weight ≦ P2 + P3 ≦ 90% by weight VI 0% by weight ≦ α2 ≦ 5% by weight VII Third step: Polymerization to satisfy the following formulas VIII and IX and the above formulas V and VI 0.5 dl / g ≦ η3 ≦ 1.5 dl / g VIII 0% by weight ≦ α3 ≦ 5% by weight IX [wherein, in the above formulas I to IX, η1: polymer produced in the first step Intrinsic viscosity (dl /
g) η2: intrinsic viscosity of polymer produced in the second step (dl /
g) η3: intrinsic viscosity of polymer produced in the third step (dl /
g) P1: Proportion (% by weight) of the polymer produced in the first step with respect to the total amount P2: Proportion (% by weight) of the polymer produced in the second step with respect to the total amount P3: Produced in the third step with respect to the total amount Ratio of polymer (% by weight) α1: Ratio of α-olefin units other than ethylene in the polymer produced in the first step (% by weight) α2: α-olefin other than ethylene in polymer produced in the second step Unit ratio (wt%) α3: ratio of α-olefin units other than ethylene (wt%) in the polymer produced in the third step], the production of an ethylene-based polymer characterized by the following: Method. 2. The method according to claim 1, wherein (A)
As the component (a), a reaction product of metallic magnesium, an alcohol, and a halogen is used in place of the magnesium alkoxide, and the method for producing an ethylene polymer.