JP5026020B2 - Polyolefin production method and polyolefin resin composition - Google Patents

Description

  The present invention relates to a method for producing a polyolefin. More specifically, compared with conventionally known methods, a polyolefin production method excellent in the balance between the rigidity and long-term characteristics of polyolefin and further excellent in molding processability, and a polyolefin resin for piping materials produced by the production method The present invention relates to a composition and a polyolefin resin composition for hollow molding.

  Conventionally, polyethylene is excellent in creep characteristics, environmental stress crack resistance, impact resistance, and flexibility, and thus has been used in various applications such as piping materials and hollow molded articles. Examples of the piping material include water and sewage pipes, gas pipes, and water supply pipes, and examples of the hollow molded body include industrial chemical containers, high-purity chemical containers, and edible oil containers manufactured by blow molding.

The method for producing polyethylene can be roughly classified into single-stage polymerization and multi-stage polymerization. In single-stage polymerization, since a single polymerization vessel is used, it is relatively easy to control conditions during production. Moreover, although the obtained polyethylene is extremely excellent in impact resistance, it is known that the obtained polyethylene is inferior in creep characteristics and environmental stress crack resistance. On the other hand, since multistage polymerization uses a plurality of polymerization vessels, it is difficult to control conditions because there are many conditions to be controlled when producing polyethylene. Moreover, although the obtained polyethylene is excellent in creep characteristics and environmental stress crack resistance, it is known that it is slightly inferior in impact resistance.
Due to the difference in the physical properties of polyethylene by the above polymerization method, polyethylene with high creep properties, environmental stress crack resistance, impact resistance and flexibility for piping materials and hollow moldings should be produced by single-stage polymerization. Is generally difficult to produce, and is generally produced by multistage polymerization.

  For example, when used as a water and sewage pipe, stress such as water pressure from the inside of the pipe or earth pressure from the outside during burial is applied, so polyethylene with excellent long-term characteristics is required to withstand long-term stress It is. On the other hand, the pipe is required to have a large diameter, and this requires high rigidity in polyethylene. On the other hand, the water and sewage pipes require a joint, and since this joint is usually manufactured by injection molding, high moldability is required. Since the water and sewage pipe and the joint are used by fusing, it is desirable that the water and sewage pipe and the joint are made of the same polyethylene in order to improve the fusing property. However, it has been difficult to achieve both high long-term characteristics and high rigidity, as well as high moldability.

  For example, Patent Document 1 discloses a polyethylene made of polyethylene having two molecular weight distributions and having an MFR5 of 0.35 g / 10 min or less. However, although this polyethylene has a high molecular weight and such a material has excellent mechanical properties and may be PE100, its molding processability is poor, and in the production of pipes and joints by actual extrusion molding and injection molding, particularly in injection molding. Productivity is expected to be very poor.

Further, Patent Document 2 discloses a composition comprising two components having different intrinsic viscosities and densities. When a molded pipe is molded using this composition, a hot internal pressure creep test, a tensile property is used as a pipe characteristic. It has been proposed that creep tests, tensile fatigue tests, and the like are dramatically improved over conventional materials. According to this, the density and intrinsic viscosity of the two-component composition of low molecular weight, high density polyethylene and high molecular weight, low density polyethylene are 0.945 to 0.970 g / cm ³ , 2.41 to 6.3 dyne, respectively. / in the range of cm ^2, the composition characterized in that the shear rate at which the shear stress of the capillary at 190 ° C. is reached ^{2.4 × 10 6 dyne / cm 2} (FI) is 350Sec ^-1 or less It is said that it is possible to form a pipe excellent in moldability, pipe fatigue characteristics, etc. when it is made into a pipe molded body, but such compositions have a high molecular weight, etc., so pipes with fatigue characteristics etc. Properties are certainly high, but it means a composition that tends to be worse in terms of molding processability, especially in injection molding for forming joints.

  Further, when used as an industrial chemical container, generally, polyethylene having improved environmental stress crack resistance by broadening the molecular weight distribution, that is, excellent in long-term characteristics is used. However, in recent years, efforts to save resources have become stronger due to the response to environmental problems, and there has been an increasing demand for thinning the thickness of molded products such as hollow molded products, resulting in high impact strength, that is, high rigidity polyethylene. Is desired. On the other hand, high productivity is also pursued in the market, and polyethylene excellent in molding processability is desired. However, it has been difficult to achieve both environmental stress crack resistance and impact strength and high moldability.

JP-A-8-301933 JP-A-8-134285

  The present invention has been made in view of the prior art as described above, and has a high activity in multi-stage polymerization, and a method for producing a polyolefin excellent in impact resistance, long-term characteristics and molding processability, and excellent in these characteristics. An object is to provide a polyolefin resin composition for piping materials and a polyolefin resin composition for hollow molding.

As a result of intensive studies to improve the drawbacks of the prior art, the present inventors have obtained a polyolefin having high activity in multi-stage polymerization and excellent impact strength, long-term characteristics and moldability by using a specific catalyst. The inventors have found that it can be produced, and have come to achieve the present invention.
That is, the present invention is a method for producing a polyolefin and a polyolefin resin composition as described below.

1) In a method for producing a polyolefin by multistage polymerization of α-olefin, a low molecular weight component having a weight average molecular weight (Mw) of 5,000 to 100,000 and a weight average molecular weight (Mw) of 20 even if the multistage polymerization is small. In which the catalyst used for the polymerization is composed of a solid catalyst [A] and an organometallic compound [B], and the solid catalyst [A] Prepared by reaction of an organomagnesium compound (a-1) soluble in an inert hydrocarbon solvent represented by formula (1) with a chlorinating agent (a-2) represented by the following general formula (2) The carrier (A-1) is reacted with an alcohol (A-2), and then an organometallic compound (A-3) represented by the following general formula (3) is reacted. 4) The titanium compound (A-4) represented by Formula (3) an organometallic compound represented by (A-5) and reacted has been prepared by supporting, magnesium contained in the alcohol (A-2) of the carrier (A-1) atoms molar ratio is 0.2 to 0.5 relative to the organometallic compound (a-3) molar ratio of the alcohol (a-2) of Ri der 0.5 to 2.5, the organometallic compound [ B] belongs to the group consisting of an organoaluminum compound represented by the following general formula (5) and an organomagnesium compound soluble in an inert hydrocarbon solvent represented by the following general formula (6): Production method of polyolefin.
(M ¹ ) _α (Mg) _β (R ¹ ) _a (R ² ) _b (OR ³ ) _c (1)
(Wherein M1 is a metal atom belonging to the group consisting of lithium, sodium, potassium, beryllium, zinc, boron, and aluminum, and R ¹ , R ² and R ³ are each a hydrocarbon group having 2 to 20 carbon atoms. And α, β, a, b, and c are real numbers that satisfy the following relationship: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 <c, 0 <a + b, 0 <c / ( α + β) ≦ 2, kα + 2β = a + b + c (where k is the valence of M ¹ ))
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are numbers satisfying the following relationship: 1 ≦ d, 1 ≦ e, 2 ≦ d + e ≦ 4)
M ² R ⁵ _f Q _(h−f) (3)
(Lithium wherein M2 is sodium, potassium, beryllium, magnesium, boron, metals belonging to the group consisting of aluminum atom, ^{R 5} is a hydrocarbon group having 1 to 20 carbon atoms, Q is ^OR 6, OSiR ⁷ R ⁸ represents a group belonging to the group consisting of R ⁹ , NR ¹⁰ R ¹¹ , SR ¹² and halogen, and R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are a hydrogen atom or a hydrocarbon group F is a real number greater than 0 and h is the valence of M ² )
Ti (OR ¹³ ) _i X _(4-i) (4)
(In the formula, i is a real number of 0 or more and 4 or less, R ¹³ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)
R ¹⁴ _(3-j) AlQ ′ _j (5)
(Wherein R ¹⁴ is a hydrocarbon group having 1 to 12 carbon atoms, Q ′ is a group belonging to the group consisting of a hydrogen atom, a halogen atom, and OR ¹⁵ , and R ¹⁵ is a group having 1 to 20 carbon atoms. And j is a real number of 0 or more and 2 or less)
(M ³ ) _γ (Mg) _δ (R ¹⁵ ) _m (R ¹⁶ ) _n (6)
(In the formula, M ³ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹⁵ and R ¹⁶ each have 2 to 20 carbon atoms. The following hydrocarbon groups, γ, δ, m and n are real numbers satisfying the following relationship: 0 ≦ γ, 0 <δ, 0 ≦ m, 0 ≦ n, pγ + 2δ = m + n (where p is M Valence of ³ ))
2 ) A polyolefin resin composition produced by the production method described in 1 ) above .
3 ) A polyolefin resin composition for piping materials produced by the production method described in 1 ) above .
4 ) A polyolefin resin composition for hollow molded articles produced by the production method described in 1 ) above .

  INDUSTRIAL APPLICABILITY According to the present invention, a polyolefin production method having high activity in multistage polymerization and excellent in impact resistance, long-term characteristics and molding processability, and a polyolefin resin composition for a piping material and a polyolefin resin composition for hollow molding excellent in these characteristics Can be provided.

Hereinafter, the present invention will be described in detail.
First, the α-olefin used in the present invention will be described. Examples of the α-olefin used in the present invention include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, cyclopentene, cyclohexene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl-1.4,5.8-dimethano -1,2,3,4,4a, 5,8,8a-octahydronaphthalene, styrene, vinylcyclohexane, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene, Examples include 1,7-octadiene and cyclohexadiene. These α-olefins can be used in combination of two or more.

  Next, the multistage polymerization method in the present invention will be described. Examples of the multistage polymerization method in the present invention include, for example, Japanese Patent Publication No. 35-15246, Japanese Patent Publication No. 46-11349, Japanese Patent Publication No. 48-42716, Japanese Patent Publication No. 51-47079, Japanese Patent Publication No. 52-19788. This is a known technique reported in Japanese Patent Publication No. 2505752 and the like, and is a method in which an α-olefin is homopolymerized or copolymerized by a multistage polymerization apparatus in which a plurality of polymerization vessels are usually connected in series.

  Next, the low molecular weight component in the present invention will be described. In the present invention, the molecular weight of the low molecular weight component is not particularly limited, but the weight average molecular weight (Mw) is preferably from 5,000 to 100,000, and more preferably from 10,000 to 70,000. . When the Mw is 5000 or more, the low molecular weight component contributes to the improvement of the physical properties of the polyolefin, so the physical properties, particularly the impact strength is improved. When the Mw is 100,000 or less, the low molecular weight component improves the molding processability. Molding processability is improved to contribute. In the present invention, Mw was measured by gel permeation chromatography (GPC).

No particular limitation is imposed on the density of the low molecular weight component is preferably not more than 950 kg / ^{m 3} or more 985kg / ^{m 3,} more preferably not more than 960 kg / ^{m 3} or more 980 kg / ^{m 3.} In the present invention, the density was measured according to JIS K7112: 1999. Although there is no restriction | limiting in particular about molecular weight distribution of this low molecular weight component, It is preferable that ratio (Mw / Mn) of Mw measured by GPC and number average molecular weight (Mn) is 3-20, It is 4-13. More preferably.

Next, the high molecular weight component in the present invention will be described. In the present invention, the molecular weight of the high molecular weight component is not particularly limited, but Mw is preferably 200,000 to 2,000,000 and more preferably 300,000 to 1,500,000. When the Mw is 200,000 or more, the long-term characteristics are excellent, and when the Mw is 2 million or less, the moldability is excellent. No particular limitation is imposed on the density of the high molecular weight component is preferably not more than 890 kg / ^{m 3} or more 970 kg / ^{m 3,} more preferably not more than 895kg / ^{m 3} or more 960 kg / ^{m 3.}

  Next, the hydrogen concentration in the polymerization vessel in the present invention will be described. In the present invention, the hydrogen concentration in the polymerization vessel during the production of the low molecular weight component is 40 mol% or more and 90 mol% or less, and preferably 45 mol% or more and 80 mol% or less. If it is 40 mol% or more, it is possible to produce a polyolefin excellent in molding processability, the molecular weight can be sufficiently controlled, and if it is 90 mol% or less, improvement in impact strength can be expected. In the present invention, the hydrogen concentration in the polymerization vessel refers to the hydrogen concentration (unit: mol / liter) obtained by analyzing the gas phase portion in the polymerization vessel using gas chromatography and the α-olefin concentration ( Is a value calculated according to the following formula using the unit: mol / liter), and the unit is mol%. The concentration indicates the gas phase concentration.

  In olefin polymerization, the molecular weight is generally controlled by the hydrogen concentration (mol%) in the polymerization vessel, and the higher the hydrogen concentration (mol%) in the polymerization vessel, the lower the molecular weight of the polyolefin produced. Therefore, in order to produce a low molecular weight component by the above-described multistage polymerization method, it is necessary to increase the hydrogen concentration in the polymerization vessel.

Next, the solid catalyst [A] in the present invention will be described.
In the present invention, the solid catalyst [A] is represented by an organomagnesium compound (a-1) soluble in an inert hydrocarbon solvent represented by the following general formula (1) and the following general formula (2). The carrier (A-1) prepared by the reaction with the chlorinating agent (a-2) is reacted with alcohol (A-2), and then an organometallic compound represented by the following general formula (3) ( It is prepared by reacting A-3) and then supporting a titanium compound (A-4) represented by the following general formula (4).

(M ¹ ) _α (Mg) _β (R ¹ ) _a (R ² ) _b (OR ³ ) _c (1)
(In the formula, M ¹ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ , R ² and R ³ are each a carbon number. 2 or more and 20 or less, and α, β, a, b, and c are real numbers that satisfy the following relationship: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 <c, 0 <a + b, 0 <c / (α + β) ≦ 2, kα + 2β = a + b + c (where k is the valence of M ¹ ))
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are numbers satisfying the following relationship: 1 ≦ d, 1 ≦ e, 2 ≦ d + e ≦ 4)
M ² R ⁵ _f Q _(h−f) (3)
(Wherein M ² is a metal atom belonging to Groups I to III of the Periodic Table, R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and Q is OR ⁶ , OSiR ⁷ R ⁸ R ⁹ , NR ¹⁰ R. ¹¹ , SR ¹² and a group belonging to the group consisting of halogen, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are hydrogen atoms or hydrocarbon groups, and f is greater than 0 A real number and h is the valence of M ² )
Ti (OR ¹³ ) _i X _(4-i) (4)
(In the formula, i is a real number of 0 or more and 4 or less, R ¹³ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)

  Next, the inert hydrocarbon solvent in the present invention will be described. The inert hydrocarbon solvent in the present invention is an aliphatic hydrocarbon compound such as pentane, hexane or heptane, an aromatic hydrocarbon compound such as benzene or toluene, or an alicyclic hydrocarbon compound such as cyclohexane or methylcyclohexane. An aliphatic hydrocarbon is preferable.

  Next, the organomagnesium compound that is soluble in the inert hydrocarbon solvent represented by the general formula (1) in the present invention will be described. This organomagnesium compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but encompasses all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds It is. The relational expression kα + 2β = a + b + c of the symbols α, β, a, b, c indicates the stoichiometry between the valence of the metal atom and the substituent.

In the general formula (1), the hydrocarbon group represented by R ¹ to R ² is an alkyl group, a cycloalkyl group or an aryl group, and examples thereof include methyl, ethyl, propyl, butyl, propyl, hexyl, octyl, Examples include decyl, cyclohexyl, and phenyl groups, and preferably R ¹ to R ² are alkyl groups. When α> 0, as the metal atom M ¹ , a metal element belonging to Groups I to III of the periodic table can be used, and examples thereof include lithium, sodium, potassium, beryllium, zinc, boron, aluminum and the like. However, aluminum, boron, beryllium, and zinc are particularly preferable.

The ratio β / α of magnesium to the metal atom M ¹ can be arbitrarily set, but is preferably in the range of 0.1 to 30, particularly 0.5 to 10. Further, when a certain organomagnesium compound in which α = 0 is used, for example, when R ¹ is 1-methylpropyl or the like, it is soluble in an inert hydrocarbon solvent, and such a compound is also used in the present invention. Gives favorable results.
In the general formula (M ¹ ) _α (Mg) _β (R ¹ ) _a (R ² ) _b (OR ³ ) _c , R ¹ and R ² when α = 0 are the following three groups (1), It is recommended that it is one of (2) and (3).

(1) At least one of R ¹ and R ² is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, preferably both R ¹ and R ² have 4 to 6 carbon atoms, At least one is a secondary or tertiary alkyl group.
(2) R ¹ and R ² are alkyl groups having different carbon atoms, preferably R ¹ is an alkyl group having 2 or 3 carbon atoms, and R ¹ is an alkyl having 4 or more carbon atoms. Be a group.
(3) At least one of R ¹ and R ² is a hydrocarbon group having 6 or more carbon atoms, preferably an alkyl group that becomes 12 or more when the number of carbon atoms contained in R ¹ and R ² is added. .

These groups are specifically shown below.
The secondary or tertiary alkyl group having 4 to 6 carbon atoms in (1) includes 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2-methylbutyl, 2-ethylpropyl, 2 , 2-dimethylpropyl, 2-methylpentyl, 2-ethylbutyl, 2,2-dimethylbutyl, 2-methyl-2-ethylpropyl group and the like are used, and 1-methylpropyl group is particularly preferable. Next, in (2), examples of the alkyl group having 2 or 3 carbon atoms include ethyl, 1-methylethyl, propyl and the like, and an ethyl group is particularly preferable. Examples of the alkyl group having 4 or more carbon atoms include butyl, pentyl, hexyl, heptyl, octyl group and the like, and butyl and hexyl groups are particularly preferable.

  Furthermore, examples of the hydrocarbon group having 6 or more carbon atoms in (3) include hexyl, heptyl, octyl, nonyl, decyl, phenyl, 2-naphthyl group and the like. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, hexyl and octyl groups are particularly preferable. In general, an increase in the number of carbon atoms contained in an alkyl group facilitates dissolution in an inert hydrocarbon solvent. However, the use of an unnecessarily long alkyl group is not preferred in terms of handling because the solution viscosity increases. The organomagnesium compound is used as an inert hydrocarbon solution, but it can be used as long as a trace amount of Lewis basic compounds such as ethers, esters, and amines are contained or remain in the solution.

Next, the alkoxy group (OR ³ ) will be described. The hydrocarbon group represented by R ³ is preferably an alkyl group or aryl group having 1 to 12 carbon atoms, and particularly preferably an alkyl group or aryl group having 3 to 10 carbon atoms. Specifically, for example, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 1,1-dimethylethyl, pentyl, hexyl, 2-methylpentyl, 2-ethylbutyl, 2-ethylpentyl, Examples include 2-ethylhexyl, 2-ethyl-4-methylpentyl, 2-propylheptyl, 2-ethyl-5-methyloctyl, octyl, nonyl, decyl, phenyl, naphthyl groups, and the like. Butyl, 1-methylpropyl, 2 -Methylpentyl and 2-ethylhexyl groups are particularly preferred.

These organomagnesium compounds include organomagnesium compounds belonging to the group consisting of general formulas R ¹ MgX and R ¹ ₂ Mg (R ¹ is as defined above and X is halogen), and general formula M ¹ R ² _k And an organometallic compound belonging to the group consisting of M ¹ R ² _(k−1) H (M ¹ , R ² , k are as defined above) in an inert hydrocarbon solvent at room temperature to 150 ° C. An alkoxymagnesium compound having a hydrocarbon group represented by R ³ that is soluble in an alcohol having an hydrocarbon group represented by R ³ or an inert hydrocarbon solvent, if necessary, and the like. It is synthesized by the method of reacting.

  Among these, when reacting an organomagnesium compound soluble in an inert hydrocarbon solvent with an alcohol, the order of the reaction is such that the alcohol is added to the organomagnesium compound, or the organomagnesium compound is added to the alcohol. Any method can be used, or a method of adding both at the same time. In the present invention, the reaction ratio between the organomagnesium compound soluble in the inert hydrocarbon solvent and the alcohol is not particularly limited, but as a result of the reaction, the alkoxy group-containing organomagnesium compound in the resulting alkoxy group-containing organomagnesium compound contains all of the alkoxy groups. The range of the molar composition ratio c / (α + β) is 0 ≦ c / (α + β) ≦ 2, and 0 ≦ c / (α + β) <1 is particularly preferable.

Next, the chlorinating agent in the present invention will be described. In the present invention, the chlorinating agent used when synthesizing (A-1) is represented by the following general formula (2), and at least one is a silicon chloride compound having a Si—H bond.
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are numbers satisfying the following relationship: 1 ≦ d, 1 ≦ e, 2 ≦ d + e ≦ 4)
In the above general formula (2), the hydrocarbon group represented by R ⁴ is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, for example, methyl, ethyl, propyl, 1 -Methylethyl, butyl, pentyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like can be mentioned, preferably an alkyl group having 1 to 10 carbon atoms, and a carbon number such as methyl, ethyl, propyl, 1-methylethyl group, etc. 1-3 alkyl groups are particularly preferred. D and e are one or more real numbers satisfying the relationship of 2 ≦ d + e ≦ 4, and e is particularly preferably 2 or more.

These compounds include HSiCl ₃ , HSiCl ₂ CH ₃ , HSiCl ₂ C ₂ H ₅ , HSiCl ₂ C ₃ H ₇ , HSiCl ₂ (1-CH ₃ C ₂ H ₅ ), HSiCl ₂ C ₄ H ₉ , HSiCl _{2 C 6 H 5, HSiCl 2 (} 4-Cl-C 6 H 4), HSiCl 2 CH = CH 2, HSiCl 2 CH 2 C 6 H 5, HSiCl 2 (1-C 10 H 7), HSiCl 2 CH 2 CH = CH ₂ , H ₂ SiClCH ₃ , H ₂ SiClC ₂ H ₅ , HSiCl (CH ₃ ) ₂ , HSiCl (C ₂ H ₅ ) ₂ , HSiClCH ₃ (1-CH ₃ C ₂ H ₅ ), HSiClCH ₃ (C _{6 H 5), HSiCl (C 6} H 5) 2 and the like, of two or more selected from these compounds or their compounds Silicon chloride compounds are used consisting of compounds. As the silicon chloride compound, trichlorosilane, monomethyldichlorosilane, dimethylchlorosilane, and ethyldichlorosilane are preferable, and trichlorosilane and monomethyldichlorosilane are particularly preferable.

  Next, the reaction between the organomagnesium compound and the chlorinating agent in the present invention will be described. In the present invention, in the reaction of the organomagnesium compound and the chlorinating agent, a chlorinating agent is previously added as a reaction solvent body, for example, a chlorine such as an inert hydrocarbon solvent, 1,2-dichloroethane, o-dichlorobenzene, dichloromethane, etc. It is preferably used after diluting with a hydrofluoric hydrocarbon or an ether-based medium such as diethyl ether or tetrahydrofuran, or a mixed medium thereof. In particular, in view of the performance of the catalyst, an inert hydrocarbon solvent is preferable. In the present invention, the reaction temperature is not particularly limited, but is preferably carried out at a temperature not lower than the boiling point of the silicon chloride compound used as a chlorinating agent or not lower than 40 ° C. for the progress of the reaction. Although there is no restriction | limiting in particular also in the reaction ratio of an organomagnesium compound and a silicon chloride compound, Usually, it is 0.01-100 mol of silicon chloride compounds with respect to 1 mol of organomagnesium compounds, Preferably, with respect to 1 mol of organomagnesium compounds, It is the range of 0.1-10 mol of silicon chloride compounds.

  With respect to the reaction method in the present invention, a method of simultaneous addition in which an organomagnesium compound and a silicon chloride compound are simultaneously introduced into the reactor, and a reaction is performed, and after the silicon chloride compound is charged in the reactor in advance, the organomagnesium compound is added to the reactor. There is a method of introducing or a method of introducing an organomagnesium compound into the reactor in advance and then introducing a silicon chloride compound into the reactor. However, the organomagnesium compound is introduced into the reactor after the silicon chloride compound is introduced into the reactor in advance. The method of introducing into is preferable. The solid component obtained by the above reaction is preferably separated by filtration or decantation, and then sufficiently washed with an inert hydrocarbon solvent to remove unreacted products or by-products.

In the present invention, the reaction between the organomagnesium compound and the silicon chloride compound can be performed in the presence of a solid. This solid may be either an inorganic solid or an organic solid, but it is preferable to use an inorganic solid. The following are mentioned as an inorganic solid.
(I) Inorganic oxide (ii) Inorganic carbonate, silicate, sulfate (iii) Inorganic hydroxide (iv) Inorganic halide (v) Double salt, solid solution or mixture of (i) to (iv)

Specific examples of the inorganic solid include silica, alumina, silica / alumina, hydrated alumina, magnesia, tria, titania, zirconia, calcium phosphate, barium sulfate, calcium sulfate, magnesium silicate, magnesium / calcium, aluminum silicate [(Mg / Ca ) O · Al ₂ O ₃ · 5SiO ₂ · nH ₂ O], potassium silicate · aluminum [K ₂ O · 3Al ₂ O ₃ · 6SiO ₂ · 2H ₂ O], magnesium iron silicate [(Mg · Fe) ₂ SiO ₄ ], Aluminum silicate [Al ₂ O ₃ · SiO ₂ ], calcium carbonate, magnesium chloride, magnesium iodide, and the like, and particularly preferred are silica, silica / alumina and magnesium chloride. The specific surface area of the inorganic solid is preferably 20 m ² / g or more, particularly preferably 90 m ² / g or more.

  Next, alcohol (A-2) in this invention is demonstrated. In the present invention, the alcohol (A-2) is preferably a saturated or unsaturated alcohol having 1 to 20 carbon atoms. Such alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 1-pentanol, Examples include hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, cyclohexanol, phenol, cresol, and the like, and linear alcohols having 3 to 8 carbon atoms are particularly preferable. It is also possible to use a mixture of these alcohols.

  In the present invention, the amount of alcohol (A-2) to be used is not particularly limited, but it is preferably more than 0.05 and 10 or less in terms of a molar ratio with respect to magnesium atoms contained in the carrier (A-1). 0.1 to 1 is more preferable, and 0.2 to 0.5 is more preferable. When the amount of alcohol (A-2) used is greater than 0.05 in terms of the molar ratio to the magnesium atom contained in the support (A-1), the Si-containing component contained in the catalyst support is efficiently removed. This is preferable because the catalytic properties are improved. Moreover, when the usage-amount of alcohol (A-2) is 10 or less by the molar ratio with respect to the magnesium atom contained in a support | carrier (A-1), an excess alcohol remains in a catalyst, and catalyst characteristics are obtained. This is preferable because the phenomenon of lowering can be suppressed. Furthermore, when the amount of alcohol (A-2) used is 0.2 or more and 0.5 or less in terms of a molar ratio to the magnesium atom contained in the carrier (A-1), the catalyst characteristics are improved. This is preferable because an appropriate amount of alcohol remaining in the catalyst remains in the catalyst. The reaction of the carrier (A-1) and the alcohol (A-2) can be carried out in the presence or absence of an inert hydrocarbon solvent. Although there is no restriction | limiting in particular in the temperature at the time of reaction, It is preferable to implement in 25 to 200 degreeC.

Next, the organometallic compound (A-3) in the present invention will be described. In the present invention, the organometallic compound (A-3) is represented by the following general formula (3).
M ² R ⁵ _f Q _(h−f) (3)
(Wherein M ² is a metal atom belonging to Groups I to III of the Periodic Table, R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and Q is OR ⁶ , OSiR ⁷ R ⁸ R ⁹ , NR ¹⁰ R. ¹¹ , SR ¹² and a group belonging to the group consisting of halogen, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are hydrogen atoms or hydrocarbon groups, and f is greater than 0 A real number and h is the valence of M ² )

In the present invention, M ² is a metal atom belonging to Groups I to III of the Periodic Table, and examples thereof include lithium, sodium, potassium, beryllium, magnesium, boron, and aluminum. Particularly preferred. The hydrocarbon group represented by R ⁵ is an alkyl group, a cycloalkyl group or an aryl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a cyclohexyl group and a phenyl group. Is an alkyl group.
Q represents a group belonging to the group consisting of OR ⁶ , OSiR ⁷ R ⁸ R ⁹ , NR ¹⁰ R ¹¹ , SR ¹² and halogen, and R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² Is a hydrogen atom or a hydrocarbon group, and Q is particularly preferably a halogen.

Examples of the organometallic compound (A-3) in the present invention include methyllithium, butyllithium, methylmagnesium chloride, methylmagnesium bromide, methylmagnesium iodide, ethylmagnesium chloride, ethylmagnesium bromide, ethylmagnesium iodide, butylmagnesium. Chloride, butylmagnesium bromide, butylmagnesium iodide, dibutylmagnesium, dihexylmagnesium, triethylboron, trimethylaluminum, dimethylaluminum bromide, dimethylaluminum chloride, dimethylaluminum methoxide, methylaluminum dichloride, methylaluminum sesquichloride, triethylaluminum, diethylaluminum Chloride, diethylaluminum Romido, diethylaluminum ethoxide, ethylaluminum dichloride, ethylaluminum sesquichloride, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, etc., organic aluminum Compounds are particularly preferred.
It is also possible to use a mixture of these compounds.

  In the present invention, the amount of the organometallic compound (A-3) used is not particularly limited, but is preferably 0.01 or more and 20 or less in terms of a molar ratio to the alcohol (A-2). It is more preferably 10 or less and more preferably 0.5 or more and 2.5 or less. If the amount of the organometallic compound (A-3) used is 0.01 or more in terms of the molar ratio with respect to the alcohol (A-2), excess alcohol can be efficiently removed. If the amount of compound (A-3) used is 20 or less in molar ratio to alcohol (A-2), the organometallic compound (A-3) reacts with the organometallic compound (A-3) reaction in the catalyst production process. Does not adversely affect subsequent processes. Furthermore, if the amount of the organometallic compound (A-3) used is 0.5 or more and 2.5 or less in terms of a molar ratio to the alcohol (A-2), the alcohol necessary for improving the catalyst characteristics is catalyzed. It is possible to leave on. In the present invention, the molar ratio with respect to the magnesium atom contained in the carrier (A-1) is preferably 0.01 or more and 20 or less, and more preferably 0.1 or more and 10 or less. Although there is no restriction | limiting in particular about the temperature of reaction, The range which is 25 degreeC or more and 200 degrees C or less and less than the boiling point of a reaction medium is preferable.

Next, the titanium compound (A-4) in the present invention will be described. In the present invention, a titanium compound represented by the following general formula (4) is used as the titanium compound (A-4).
Ti (OR ¹³ ) _i X _(4-i) (4)
(In the formula, i is a real number of 0 or more and 4 or less, R ¹³ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)
Examples of the hydrocarbon group represented by R ¹³ include aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, decyl, and allyl groups, cyclohexyl, and 2-methylcyclohexyl. , An alicyclic hydrocarbon group such as cyclopentyl group, and an aromatic hydrocarbon group such as phenyl and naphthyl group. An aliphatic hydrocarbon group is preferable. Examples of the halogen atom represented by X include chlorine, bromine and iodine, with chlorine being preferred. Specifically, titanium tetrachloride is preferable. Two or more kinds of titanium compounds (A-4) selected from the above can be mixed and used.

  In the present invention, the amount of the titanium compound (A-4) used is not particularly limited, but the amount supported on the carrier (A-1) is the molar ratio to the magnesium atom contained in the carrier (A-1). 0.01 or more and 20 or less are preferable, and 0.05 or more and 10 or less are particularly preferable. If the amount of the titanium compound (A-4) supported on the carrier (A-1) is too small, the polymerization activity per catalyst is low, and if it is too large, the polymerization activity per titanium tends to be low. If the amount of the titanium compound (A-4) supported on the carrier (A-1) is 0.01 or more in terms of the molar ratio to the magnesium atom contained in the carrier (A-1), the polymerization activity per catalyst is sufficiently high. If it is high and 20 or less, the polymerization activity per titanium is sufficiently high. In the present invention, the reaction temperature during the loading is not particularly limited, but it is preferably carried out in the range of 25 ° C. or more and 150 ° C. or less.

  In this invention, when carrying | supporting a titanium compound (A-4), it carries | supports by making a titanium compound (A-4) and an organometallic compound (A-5) react. This organometallic compound (A-5) is a compound represented by the aforementioned general formula (3), and may be the same as or different from the aforementioned organometallic compound (A-3).

  The order of the reaction between (A-4) and (A-5) is not particularly limited, and (A-5) is added following (A-4). Following (A-5), (A- Any method of adding 4) and adding (A-4) and (A-5) at the same time is possible, and (A-4) is preferably added following (A-4). The molar ratio of (A-5) to (A-4) is preferably 0.1 to 10, particularly preferably 0.5 to 5. The reaction between (A-2) and (A-5) is carried out in an inert hydrocarbon solvent, but it is preferable to use an aliphatic hydrocarbon solvent such as hexane or heptane. Although there is no restriction | limiting in particular about the temperature of reaction, The range which is 25 degreeC or more and 200 degrees C or less and less than the boiling point of a reaction medium is preferable.

Next, the organometallic compound [B] in the present invention will be described. The organometallic compound [B] belongs to the group consisting of an organoaluminum compound represented by the following general formula (5) and an organomagnesium compound that is soluble in an inert hydrocarbon solvent represented by the following general formula (6). The organoaluminum compound in the present invention is represented by the following general formula (5).
R ¹⁴ _(3-j) AlQ ′ _j (5)
(Wherein R ¹⁴ is a hydrocarbon group having 1 to 12 carbon atoms, Q ′ is a group belonging to the group consisting of a hydrogen atom, a halogen atom, and OR ¹⁵ , and R ¹⁵ is a group having 1 to 20 carbon atoms. And j is a real number of 0 or more and 2 or less)
Examples of R ¹⁴ include methyl, ethyl, propyl, butyl, 2-methylpropyl, pentyl, 3-methylbutyl, hexyl, octyl, decyl, phenyl, tolyl, and the like. Of these, an ethyl group and a 2-methylpropyl group are particularly preferable. Two or more kinds of these hydrocarbon groups may be contained. j is preferably from 0.05 to 1.5, particularly preferably from 0.1 to 1.2.

Next, the organomagnesium compound in the present invention is represented by the following general formula (6).
(M ³ ) _γ (Mg) _δ (R ¹⁵ ) _m (R ¹⁶ ) _n (6)
(In the formula, M ³ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹⁵ and R ¹⁶ each have 2 to 20 carbon atoms. The following hydrocarbon groups, γ, δ, m and n are real numbers satisfying the following relationship: 0 ≦ γ, 0 <δ, 0 ≦ m, 0 ≦ n, pγ + 2δ = m + n (where p is M Valence of ³ ))
This organomagnesium compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but encompasses all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds It is. The relationship between the symbols γ, δ, m and n, pγ + 2δ = m + n, indicates the stoichiometry between the valence of the metal atom and the substituent.

In the general formula (6), the hydrocarbon group represented by R ¹⁵ and R ¹⁶ is an alkyl group, a cycloalkyl group, or an aryl group. For example, methyl, ethyl, propyl, butyl, propyl, hexyl, octyl, decyl, cyclohexyl, phenyl and the like, and preferably ^{R 15} and ^{R 16} alkyl groups. When γ> 0, as the metal atom M ³ , metal elements belonging to Groups I to III of the periodic table can be used, and examples thereof include lithium, sodium, potassium, beryllium, zinc, boron, aluminum and the like. However, aluminum, boron, beryllium, and zinc are particularly preferable.

In the present invention, the ratio δ / γ of magnesium to the metal atom M ³ is not particularly limited, but is preferably 0.1 or more and 30 or less, and more preferably 0.5 or more and 10 or less. In addition, when an organomagnesium compound in which γ = 0 is used, for example, when R ¹⁵ is 1-methylpropyl or the like, it is soluble in an inert hydrocarbon solvent, and such a compound also has preferable results in the present invention. give. In the general formula (6), it is recommended that R ¹⁵ and R ^{16 in} the case of γ = 0 are any one of the following three groups (1), (2), and (3).

(1) At least one of R ¹⁵ and R ¹⁶ is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, preferably both R ¹⁵ and R ¹⁶ have 4 to 6 carbon atoms. Yes, and at least one is a secondary or tertiary alkyl group.
(2) R ¹⁵ and R ¹⁶ are alkyl groups having different carbon atoms, preferably R ¹⁵ is an alkyl group having 2 or 3 carbon atoms, and R ¹⁶ is an alkyl group having 4 or more carbon atoms. Be a group.
(3) At least one of R ¹⁵ and R ¹⁶ is a hydrocarbon group having 6 or more carbon atoms, preferably an alkyl group that becomes 12 or more when the number of carbon atoms contained in R ¹⁵ and R ¹⁶ is added. .

These groups are specifically shown below. Examples of the secondary or tertiary alkyl group having 4 to 6 carbon atoms in (1) include 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2-methylbutyl, 2-ethylpropyl, 2,2-dimethylpropyl, 2-methylpentyl, 2-ethylbutyl, 2,2-dimethylbutyl, 2-methyl-2-ethylpropyl group and the like are used, and 1-methylpropyl group is particularly preferable.
Next, examples of the alkyl group having 2 or 3 carbon atoms in (2) include ethyl, 1-methylethyl, propyl and the like, and an ethyl group is particularly preferable. Examples of the alkyl group having 4 or more carbon atoms include butyl, pentyl, hexyl, heptyl, octyl group and the like, and butyl and hexyl groups are particularly preferable.
Furthermore, examples of the hydrocarbon group having 6 or more carbon atoms in (3) include hexyl, heptyl, octyl, nonyl, decyl, phenyl, 2-naphthyl group and the like. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, hexyl and octyl groups are particularly preferable. In general, an increase in the number of carbon atoms contained in an alkyl group facilitates dissolution in an inert hydrocarbon solvent. However, the use of an unnecessarily long alkyl group is not preferred in terms of handling because the solution viscosity increases. The organomagnesium compound is used as an inert hydrocarbon solution, but it can be used as long as a trace amount of Lewis basic compounds such as ethers, esters, and amines are contained or remain in the solution.

These organomagnesium compounds include an organomagnesium compound belonging to the group consisting of the general formulas R ¹⁵ MgX and R ¹⁵ ₂ Mg (R ¹⁵ is as defined above, X is a halogen), and the general formula M ³ R ¹⁶ _p And an organometallic compound belonging to the group consisting of M ³ R ¹⁶ _(p-1) H (M ³ , R ¹⁶ , p is as defined above) in an inert hydrocarbon solvent at a temperature of 25 ° C. or higher and 150 ° C. or lower. It is synthesized by the method of reacting between them.

In the present invention, the polyolefin production method is not particularly limited, and can be applied to any of the commonly used solution methods, high-pressure methods, high-pressure bulk methods, gas methods, and slurry methods.
For example, the polymerization pressure is from 0.1 MPa to 200 MPa as the gauge pressure, the polymerization temperature is from 25 ° C. to 250 ° C., and propane, butane, isobutane, hexane, cyclohexane or the like is used as the solvent.

In the present invention, it is preferable to produce the following polyolefin using the aforementioned catalyst.
-The produced low molecular weight component MFR 2.16 is 100 to 400 g / 10 min or less,
The density of low molecular weight components (JIS K7112-1999) is 967-977 kg / m ³ ,
-The MFR5 of the polyolefin produced by multistage polymerization is 0.25 to 0.50 g / 10 minutes,
Density (JIS K7112-1999) is 943~957kg / ^{m 3,}
-Mw / Mn is 25-40,
The mass ratio of the high molecular weight component (B) to the sum of the low molecular weight component amount and the high molecular weight component amount is 0.43 to 0.48,
Is a polyolefin.

If the low molecular weight component MFR 2.16 is 100 g / 10 min or more, the molding processability is excellent, and if it is 300 or less, good impact resistance is exhibited. If the density of the low molecular weight component is 967 kg / m ³ or more, the tensile creep property, which is one of the long-term characteristics, is good, and 977 kg / m ³ is the limit for increasing the density of the polyolefin. If the MFR5 of the polyolefin produced by multistage polymerization is 0.25 g / 10 min or more, the moldability is excellent, and if it is 0.50 g / 10 min or less, the thermal tube internal pressure creep property, which is an indicator of long-term characteristics, and High fatigue resistance. If the density of the polyolefin produced by multistage polymerization is 943 kg / m ³ or more, the heat pipe internal pressure creep property at high stress, which is one of the indicators of long-term characteristics, is good, and if it is 957 kg / m ³ or less, The thermal tube internal pressure creep property at low stress, which is one of the long-term characteristics, is good. If the Mw / Mn of the polyolefin produced by multistage polymerization is 25 or more, the moldability is excellent, and if it is 40 or less, the tensile fatigue resistance, which is one of the indicators of long-term characteristics, is good. If the mass ratio of the high molecular weight component (B) to the sum of the low molecular weight component amount and the high molecular weight component amount is 0.43 or more, the tensile fatigue resistance, which is one of the long-term characteristics, is good. If it is 0.48 or less, the heat pipe internal pressure creep property, which is one of the indicators of long-term characteristics, is good.

FIG. 1 shows a flow sheet for explaining the outline of the method for producing a polyolefin of the present invention.
The polyolefin obtained by the present invention has high rigidity, excellent long-term characteristics, and excellent molding processability, and therefore is suitably used for water pipes.
Next, the present invention will be described more specifically based on examples and reference examples, but the present invention is not limited to these examples.

First, the measurement method used in the examples will be described.
[Measurement of polymerization activity]
The polymerization activity in the examples was calculated from the amount of catalyst introduced into the polymerization vessel, the amount of polymer produced, the average residence time, and the pressure in the polymerization vessel. The solid catalyst component 1 g, the average residence time 1 hour, the polymerization It represents the amount of polymer produced (g) per 1 MPa pressure in the vessel.
[Measurement of MFR]
MFR 2.16 was measured according to JIS K7210-1999, code D. MFR5 was measured according to JIS K7210-1999, code T.

[Measurement of molecular weight distribution (Mw / Mn)]
The apparatus used for the measurement was Waters 150-C ALC / GPC. The columns used were one Shodex AT-807S manufactured by Showa Denko KK and two TSK-gelGMH-H6 manufactured by Tosoh Corporation, first passing through one Shodex AT-807S and then two TSK-gelGMH. -Used in series connected through H6. As the mobile phase solvent, 1,2,4-trichlorobenzene containing 10 ppm by weight of pentaerythrityl tetrakis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] was used. The measurement temperature was 140 ° C. The mobile phase solvent flow rate was 1.0 ml / min. A measurement sample was prepared by dissolving 20 mg of polymer in 20 ml of 1,2,4-trichlorobenzene containing 0.1% by mass of 2,6-di-t-butyl-4-methylphenol. The detector was Perkin Elmer FT-IR 1760X. The number average molecular weight (Mn) is 0.43 (polyethylene Q factor / polystyrene Q factor) using a calibration curve prepared using a monodispersed polystyrene manufactured by Tosoh Corporation as a standard substance. = 17.7 / 41.3). The weight average molecular weight (Mw) is 0.43 (polyethylene Q factor / polystyrene Q factor) using a calibration curve prepared using a monodisperse polystyrene manufactured by Tosoh Corporation as a standard substance. = 17.7 / 41.3). The value of Mw / Mn, which is a measure of molecular weight distribution, was calculated by dividing the value of Mw calculated by the above method by the value of Mn.

[Density measurement]
The density of polyolefin was measured by a density gradient tube method (23 ° C.) in accordance with JIS K7112-1999.
[Create specimen]
The test piece used for the measurement of Charpy impact strength and the measurement of ESCR was performed according to JIS K6922-2-1997.
[Measurement of Charpy impact strength]
Charpy impact strength was measured as a measure of impact resistance. The measurement was performed according to JIS K7111-1996.
[Measurement of b-ESCR]
B-ESCR was measured as a measure of long-term properties. The measurement was performed according to JIS K6922-2 appendix. As a test solution, a 10% by weight aqueous solution of Liponox NC-140 (registered trademark) manufactured by Lion Corporation was used.

[ Catalyst Preparation Reference Example 1]
Preparation of solid catalyst [A-1] (1) Synthesis of carrier {(A-1) -1} 1460 ml of 1 mol / l trichlorosilane hexane solution was charged into a fully nitrogen-substituted 8 l stainless steel autoclave at 50 ° C. 1864 ml (equivalent to 1336 mmol of magnesium) of a hexane solution of an organomagnesium compound represented by the composition formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OC ₂ H ₅ ) ₂ was added dropwise over ₄ h while stirring at 50 ° C. The reaction was allowed to stir for 1 h. After completion of the reaction, the supernatant was removed and washed 4 times with 1800 ml of hexane. As a result of analyzing this support, the amount of magnesium contained per 1 g of the support was 8.72 mmol.

(2) Preparation of solid catalyst [A-1] 140 ml of 1 mol / l 2-butanol hexane solution was added over 20 minutes to 3500 ml of hexane slurry containing 160 g of the above support while stirring at 50 ° C. The molar ratio of 2-butanol to magnesium atoms contained in the carrier {(A-1) -1} was 0.10. After the addition, the reaction was continued at 50 ° C. for 1 hour. After completion of the reaction, 1800 ml of the supernatant was removed, 1128 ml of hexane was added, 700 ml of a 1 mol / l diethylaluminum chloride hexane solution was added over 1 hour and 30 minutes at a temperature of 65 ° C. The molar ratio of diethylaluminum chloride to magnesium atoms contained in the carrier {(A-1) -1} was 0.50, and the molar ratio of diethylaluminum chloride to 2-butanol was 5.0. After the addition, the reaction was continued at 65 ° C. for 1 hour. After completion of the reaction, 1800 ml of the supernatant was removed and washed 4 times with 1800 ml of hexane. 168 ml of the supernatant of the slurry after washing was removed, and 86 ml of 1 mol / l diethylaluminum chloride hexane solution was added over 5 minutes while stirring at 50 ° C., followed by 5 ml of 86 ml of 1 mol / l titanium tetrachloride hexane solution. Added over minutes. After the addition, the reaction was continued at 50 ° C. for 2 hours. After completion of the reaction, 1800 ml of the supernatant was removed, and the solid catalyst component [C] was prepared by washing 4 times with 1800 ml of hexane. The amount of titanium contained in 1 g of this solid catalyst component was 0.52 mmol.

[ Catalyst Preparation Reference Example 2]
Preparation of solid catalyst [A-2] The carrier {(A-1) -1} was used as a carrier. A catalyst was prepared in the same manner as in Catalyst Preparation Reference Example 1 except that the 2-butanol hexane solution used was 350 ml and the diethylaluminum chloride solution used immediately after the 2-butanol hexane solution was 490 ml. The molar ratio of 2-butanol to magnesium atoms contained in the carrier {(A-1) -1} was 0.25. The molar ratio of diethylaluminum chloride to magnesium atoms contained in the carrier {(A-1) -1} was 0.35, and the molar ratio of diethylaluminum chloride to 2-butanol was 1.4. The amount of titanium contained in 1 g of this solid catalyst component was 0.50 mmol.

[ Catalyst Preparation Reference Example 3]
Preparation of solid catalyst [A-3] 3910 ml of 0.64 mol / l butylethylmagnesium hexane solution and 1.0 mol / l triisobutylaluminum hexane solution in a fully nitrogen-substituted 8 l stainless steel autoclave 830 ml was mixed. This solution was concentrated 3 times, and the concentration of the solution was adjusted to 1.0 mol / l in terms of the sum of magnesium atoms and aluminum atoms.
To 400 ml of the above solution containing 30 mmol of magnesium atoms, 82 ml of 1-butanol was added together with 82 ml of hexane while adjusting the reaction temperature to 35 ° C., and the mixture was aged at 50 ° C. for 1 hour. Furthermore, 30 ml of 1 mol / l tetra-n-butoxytitanium was added dropwise. The solution obtained by this reaction was uniform and colorless and transparent, and the magnesium concentration in the solution was 0.5 mol / l.
To the titanium-containing magnesium solution obtained by the above reaction, 710 ml of 1.7 mol / l ethylaluminum dichloride was added while adjusting the reaction temperature to 25 ° C., followed by aging at 50 ° C. for 2 hours. A slurry was obtained. The resulting slurry was washed with hexane by decantation until the liquid phase aluminum component became 1/64. The amount of titanium contained in 1 g of this solid catalyst component was 0.71 mmol.

[ Reference Example 1 ]
(1) Polymerization First, in the first stage polymerization, a stainless polymerizer 1 having a reaction volume of 300 liters was used to produce a low molecular weight component. The sum of the volume of the solvent in the polymerization vessel and the volume of the polyolefin measured by a liquid level meter using γ-rays is 170 L, and the rate per volume at which the solvent and the polyolefin are regularly extracted from the polymerization vessel is 51 L. Liter / h. Therefore, the average residence time in the first stage was 3.3 hours. Low molecular weight components were withdrawn from the polymerization vessel 1 at a rate of 10 kg / h. Under the conditions of a polymerization temperature of 83 ° C. and a polymerization pressure of 1 MPa, the catalyst was the above solid catalyst [A-1] in terms of Ti atom, 1.4 mmol / h, and the organometallic compound [B] in terms of triisobutylaluminum in terms of Al atom. 20 mmol / h and hexane were introduced at a rate of 40 l / h. Hydrogen was used as a molecular weight modifier, and polymerization was carried out by supplying ethylene and hydrogen so that the gas phase concentration of hydrogen was 78 mol%. Further, the gas phase concentration of hydrogen is a value calculated by the following equation using a value obtained by gas phase analysis using gas chromatography. Note that the concentration in the following formula represents the gas phase concentration.

The polymerization activity in the polymerization vessel 1 was 3100 g / g / h. The low molecular weight component MFR2.16 produced in the polymerization vessel 1 was 300 g / 10 min, and the density was 976 kg / m ³ .
In order to remove hydrogen in the polymer slurry, the polymer slurry solution in the polymerizer 1 is led to a flash drum having a pressure of 0.1 MPa and a temperature of 75 ° C. at a rate of 51 liter / h, and unreacted ethylene and hydrogen are separated. Then, the polymer slurry solution was mixed at a rate of 51 liter / h and hexane was mixed at a rate of 95 liter / h and introduced into the polymerization vessel 2 in the next stage after being pressurized.

Next, in the second stage polymerization, a stainless polymerizer 2 having a reaction volume of 300 liters was used to produce a high molecular weight component. The polymer slurry solution and hexane were combined and introduced into the polymerization vessel 2 at a rate of 146 l / h. The sum of the volume of the solvent in the polymerization vessel and the volume of the polyolefin measured by a liquid level gauge using γ-rays is 146 liters, and the rate per volume at which the solvent and polyolefin are constantly extracted from the polymerization vessel is It was 157 liter / h. Therefore, the average residence time of the second stage was 0.93 hours.
In the polymerization vessel 2, triisobutylaluminum was introduced as the organometallic compound [B] at 47 mmol / h in terms of Al atoms under the conditions of a temperature of 70 ° C. and a pressure of 0.5 MPa. Ethylene, hydrogen and 1-butene were introduced so that the gas phase concentration of hydrogen was 3.2 mol% and the gas phase concentration of 1-butene was 12 mol%. The high molecular weight component was polymerized so that the mass ratio of the high molecular weight component produced in the polymerization vessel 2 to the sum of the molecular weight component and the high molecular weight component produced in the polymerization vessel 2 was 0.45. The gas phase concentration of hydrogen was calculated using Equation (2) above. The gas phase concentration of 1-butene is a value calculated by the following mathematical formula (3). Note that the concentration in the following formula represents the gas phase concentration.
A polyolefin composition comprising a low molecular weight component and a high molecular weight component was withdrawn from the polymerization vessel 2 at a rate of 20 kg / h. The polymerization activity in the polymerization vessel 2 was 9300 g / g / h. The obtained slurry was dried to obtain polyolefin powder.

(2) Physical property measurement The pellet was obtained by granulating the polyolefin powder obtained by the said superposition | polymerization. Physical properties were measured using this pellet. The results are shown in Table 1.

[ Example 1 ]
(1) Polymerization The solid catalyst [A-2] is used as a catalyst, the gas phase concentration of hydrogen in the first stage polymerization vessel is 75 mol%, and the gas phase concentration of hydrogen in the second stage polymerization vessel is 3. Polymerization was carried out in the same manner as in Reference Example 1 except that the gas phase concentration of 9 mol% and 1-butene was changed to 11.5 mol%. The polymerization activities in the polymerization vessel 1 and the polymerization vessel 2 were 3000 g / g / h and 9100 g / g / h, respectively.
(2) Physical property measurement
Physical properties were measured in the same manner as in Reference Example 1 . The results are shown in Table 1.

[ Comparative Example 1 ]
(1) Polymerization Using the solid catalyst [A-3] as the solid catalyst, the gas phase concentration of hydrogen in the first stage polymerization vessel is 85 mol%, and the gas phase concentration of hydrogen in the second stage polymerization vessel is 4 Polymerization was carried out in the same manner as in Reference Example 1 except that the gas phase concentration of 1 mol. The polymerization activity in the polymerization vessel 1 was 3400 g / g / h, and the polymerization activity in the polymerization vessel 2 was 10200 g / g / h.
(2) Physical property measurement
Physical properties were measured in the same manner as in Reference Example 1 . The results are shown in Table 1.

From Table 1, all polyolefins have MFR5 of 0.25 g / 10 min or more, so the moldability is good, and b-ESCR is 50 hours or more, so the long-term characteristics are at a high level. It was confirmed that the polyolefin of the comparative example had a very low Charpy impact strength of 10 kg · cm / cm ² and was inferior in impact resistance.

  INDUSTRIAL APPLICABILITY The present invention can provide a method for producing a polyolefin having high activity in multistage polymerization and excellent in impact resistance, long-term characteristics and molding processability, and is particularly suitable for producing a polyolefin suitable for pipes.

It is a flow sheet figure explaining the outline of the manufacturing method of polyolefin of the present invention.

Claims (4)

In the method for producing a polyolefin by multistage polymerization of α-olefin, a low molecular weight component having a weight average molecular weight (Mw) of 5,000 to 100,000 and a weight average molecular weight (Mw) of 200,000 or more even if the multistage polymerization is small. And a polymer used for the polymerization is composed of a solid catalyst [A] and an organometallic compound [B], and the solid catalyst [A] is represented by the following general formula ( 1) prepared by a reaction of an organomagnesium compound (a-1) soluble in an inert hydrocarbon solvent represented by 1) and a chlorinating agent (a-2) represented by the following general formula (2) The carrier (A-1) is reacted with the alcohol (A-2), then the organometallic compound (A-3) represented by the following general formula (3) is reacted, and then the following general formula (4) The titanium compound (A-4) represented by It has been prepared by organometallic compound (A-5) is reacted with supported represented by the formula (3), to magnesium atoms contained in the carrier of the alcohol (A-2) (A- 1) molar ratio is 0.2 to 0.5, an organometallic compound (a-3) molar ratio of the alcohol (a-2) of Ri der 0.5 to 2.5, the organometallic compound [B ] Belonging to the group consisting of an organoaluminum compound represented by the following general formula (5) and an organomagnesium compound soluble in an inert hydrocarbon solvent represented by the following general formula (6) Manufacturing method.
(M ¹ ) _α (Mg) _β (R ¹ ) _a (R ² ) _b (OR ³ ) _c (1)
(Wherein M ¹ is a metal atom belonging to the group consisting of lithium, sodium, potassium, beryllium, zinc, boron and aluminum, and R ¹ , R ² and R ³ are each a hydrocarbon group having 2 to 20 carbon atoms. And α, β, a, b, and c are real numbers that satisfy the following relationships: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 <c, 0 <a + b, 0 <c / (Α + β) ≦ 2, kα + 2β = a + b + c (where k is the valence of M ¹ ))
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are real numbers satisfying the following relationship: 1 ≦ d, 1 ≦ e, 2 ≦ d + e ≦ 4)
M ² R ⁵ _f Q _(h−f) (3)
(Wherein M ² is a metal atom belonging to the group consisting of lithium, sodium, potassium, beryllium, magnesium, boron and aluminum, R 5 is a hydrocarbon group having 1 to 20 carbon atoms, and Q is OR ⁶ , OSiR ⁷ R ⁸ represents a group belonging to the group consisting of R ⁹ , NR ¹⁰ R ¹¹ , SR ¹² and halogen, and R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are a hydrogen atom or a hydrocarbon group F is a real number greater than 0 and h is the valence of M ² )
Ti (OR ¹³ ) _i X _(4-i) (4)
(In the formula, i is a real number of 0 or more and 4 or less, R ¹³ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)
R ¹⁴ _(3-j) AlQ ′ _j (5)
(Wherein R ¹⁴ is a hydrocarbon group having 1 to 12 carbon atoms, Q ′ is a group belonging to the group consisting of a hydrogen atom, a halogen atom, and OR ¹⁵ , and R ¹⁵ is a group having 1 to 20 carbon atoms. And j is a real number of 0 or more and 2 or less)
(M ³ ) _γ (Mg) _δ (R ¹⁵ ) _m (R ¹⁶ ) _n (6)
(In the formula, M ³ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹⁵ and R ¹⁶ each have 2 to 20 carbon atoms. The following hydrocarbon groups, γ, δ, m and n are real numbers satisfying the following relationship: 0 ≦ γ, 0 <δ, 0 ≦ m, 0 ≦ n, pγ + 2δ = m + n (where p is M Valence of ³ )) A polyolefin resin composition produced by the production method according to claim 1 . The polyolefin resin composition for piping materials manufactured by the manufacturing method of Claim 1 . A polyolefin resin composition for a hollow molded article produced by the production method according to claim 1 .

Images