JP2008179799A - Polyethylene resin composition for large-sized high purity chemical container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for a large-sized high purity chemical container, which is reduced in the amount of fine particles and eluting components, and excellent in surface roughing resistance during molding. <P>SOLUTION: The polyethylene resin composition essentially contains a polyethylene resin component composed of a low molecular weight component and a high molecular weight component, and has been produced by the multistage polymerization using a Ziegler catalyst. The low molecular weight component is an ethylene homopolymer or a copolymer of ethylene with a 3-20C α-olefin, having 3-50 g/10 min melt flow rate (MFR code D) and 960-974 kg/m<SP>3</SP>density. The high molecular weight component has 0.40-0.46 mass fraction to the composition. The composition has 955-965 kg/m<SP>3</SP>density, and 0.40-1.0 g/10 min MFR (code T); and contains substantially no additive. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polyethylene resin composition having a small amount of fine particles and eluted components and having excellent skin roughness during molding, and the polyethylene resin composition of the present invention is used for high-purity chemical containers that require cleanliness. Suitable as a resin material.

  In recent years, the demand for high-purity chemicals has increased with the remarkable development of the electronics industry. High-purity chemicals are used, for example, as chemicals indispensable for manufacturing electronic circuits such as large-scale and integrated LSIs. Specifically, sulfuric acid, hydrochloric acid, nitric acid, hydrogen fluoride are used for wafer cleaning / etching, wiring / insulating film etching, jig cleaning, developer, resist diluent, resist stripper, drying, etc. Acid, ammonium fluoride, hydrogen peroxide, 2-propanol, xylene, TMAH (tetramethylammonium hydroxide), methanol, acetic acid, phosphoric acid, aqueous ammonia, PGMEA (propylene glycol methyl ether acetate), DMSO (dimethyl sulfoxide) NMP (N-methylpyrrolidinone), ECA (ethyl cyanoacrylate), ethyl lactate and the like are used.

  Conventionally, polyethylene resins have been used as these materials for containers for high-purity chemicals in terms of chemical resistance, impact resistance, price, and the like. However, conventional containers made of polyethylene resin have a problem of contamination of the contents by contaminants such as eluate and deteriorated products of the resin due to chemicals, and have a limit for use in high-purity chemical containers. That is, with the miniaturization of the VLSI, the metal impurity concentration is conventionally required to be 1 PPB or less, but at present, it is required to be 0.1 PPB or less. Conventionally, fine particles having a size of 0.5 μm or more have been problematic, but fine quality of 0.2 μm or more is required to be 100 particles / ml or less, and more stringent quality is required. On the other hand, polyethylene resins are required to have characteristics required for general containers, for example, long-term characteristics such as ESCR (environmental stress crack resistance), impact strength, which is an index of safety when dropped. ing.

  On the other hand, when manufacturing a container made of polyethylene resin, moldability of the polyethylene resin is required. When a container is molded using a polyethylene resin with poor moldability, the surface of the container, particularly the inner surface, becomes rough and the surface area increases, resulting in a decrease in cleanliness due to an increase in elution components. . In order to improve the moldability, it is generally effective to widen the molecular weight distribution or lower the molecular weight in order to improve fluidity. However, these improved methods have a problem of deterioration of moldability such as drawdown in large-sized molded products as well as a decrease in cleanliness due to an increase in eluted components.

  That is, in order to improve the cleanliness of the resin itself, it is necessary to reduce the low molecular weight component contained in the resin. Therefore, if the molecular weight distribution of the resin is narrowed to reduce the low molecular weight component, the cleanliness of the resin itself is improved. However, if the molecular weight distribution is narrowed, the surface of the molded product tends to be rough. Therefore, in order to improve the rough skin, multistage polymerization is often performed in which another resin having a narrow molecular weight distribution is introduced into the high molecular weight region. However, adding only a high molecular weight component will increase the overall molecular weight, resulting in rough skin.If the overall molecular weight is lowered to match the molecular weight, cleanliness will deteriorate, and large blow molding will draw down. There was a problem that it could not be molded.

Several polyethylene resin compositions for high-purity chemical containers are disclosed.
For example, a resin composition is disclosed in which the molecular weight distribution (= weight average molecular weight / number average molecular weight) is extremely narrow to improve cleanliness and improve impact resistance (see, for example, Patent Document 1). However, this resin composition has improved cleanliness, but when the melt flow (MFR) is low, the skin becomes rough during extrusion, and when it is high, drawdown becomes remarkable, which makes it difficult to mold a large blow container. .

Moreover, the resin composition with narrow molecular weight distribution obtained by using two-stage polymerization is disclosed (for example, refer patent document 2). Although this resin composition has improved cleanliness and improved long-term stability, the rough skin property at the time of extrusion of the low MFR resin composition suitable for large blow has not been solved yet. Since you are added with a small amount of neutralizing agent and a heat stabilizer it was really caused the cleanness drops.
Moreover, the resin composition which improved the cleanliness using the single site catalyst is disclosed (for example, refer patent document 3). However, the rough skin property has not been improved, and there has been room for improvement in the drawdown property in large-sized molded product applications.
The large size here refers to a bottle whose internal capacity is 10L or more.

Japanese Patent Application Laid-Open No. 9-79721 Japanese Patent Laid-Open No. 11-80257 Japanese Patent Laid-Open No. 11-246714

  An object of the present invention is to provide a polyethylene resin composition for high-purity chemical containers that has few fine particles and elution components derived from polyethylene resin and has few elution components, is excellent in molding processability, particularly rough skin during molding, and has excellent ESCR. It is.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition having a specific melt flow and molecular weight distribution and substantially free of additives is suitable for a large high-purity chemical container. The headline and the present invention were made.
That is, the present invention is a polyethylene resin composition as described below and a large-sized high-purity chemical container using the same.

(1) The polyethylene resin composition contained in the polyethylene resin composition is a polyethylene resin composition produced using a Ziegler catalyst by a multistage polymerization method comprising at least a low molecular weight component and a high molecular weight component, wherein the low molecular weight component but the melt flow rate (JIS K7210-1999, code D) is 3 g / 10 min or more 50 g / 10 minutes or less, the density (JIS K7112-1999) is ethylene or less 960 kg / ^{m 3} or more 974kg / ^{m 3} homo- A polymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, wherein a mass fraction of the high molecular weight component to the polyethylene resin composition is 0.40 or more and 0.46 or less, polyethylene resin composition, density (JIS K7112-1999) is 955 kg / ^{m 3} or more 965k / ^{M 3} or less, a melt flow rate (JIS K7210-1999, code T) is not less than 1.0 g / 10 min or less 0.40 g / 10 min, a large height, characterized in that it is substantially free of additives Polyethylene resin composition for pure chemical containers.
(2) A large-sized high-purity chemical container formed by molding the polyethylene resin composition described in 1 above.

  According to the present invention, it is possible to provide a polyethylene resin composition for a large-sized high-purity chemical container that has few fine particles and elution components derived from a polyethylene resin and additives, is excellent in molding processability, particularly rough skin during molding, and has excellent ESCR. it can.

The present invention will be specifically described below.
In the present invention, high-purity chemicals are used as chemicals indispensable for the manufacture of electronic circuits such as large-scale and integrated LSIs. For wafer cleaning / etching, wiring / insulating film etching It is used for cleaning jigs, developing solutions, resist diluents, resist strippers, and drying. The purity of the high purity chemical in the present invention is 99.9% or more. High purity chemicals include sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, ammonium fluoride, hydrogen peroxide, isopropyl alcohol, xylene, TMAH (tetramethylammonium hydroxide), methanol, acetic acid, phosphoric acid, aqueous ammonia, PGMEA (propylene glycol methyl ether acetate), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidinone), ECA (ethyl cyanoacrylate), ethyl lactate and the like can be mentioned.

The resin composition of the present invention is suitable for a large container having a capacity of 1 L or more, more preferably a large container of 5 L or more, and further suitable for a large container of 10 L or more.
The Ziegler catalyst in the present invention is an olefin polymerization catalyst containing a titanium chloride compound and an alkylaluminum compound as essential components (see, for example, P.836 of the Riken Dictionary 5th edition (Iwanami Shoten)). In the present invention, the Ziegler catalyst production method is not particularly limited, but is preferably a Ziegler catalyst produced by the following production method.

That is, the Ziegler catalyst in the present invention comprises a solid catalyst component [A] and an organometallic compound component [B], and the solid catalyst component [A] is an inert hydrocarbon solvent represented by the following general formula (1). A carrier (A-3) prepared by the reaction of a soluble organomagnesium compound (A-1) and a chlorinating agent (A-2) represented by the following general formula (2) has the following general formula (3 It is preferable that it is a Ziegler catalyst for olefin polymerization produced by carrying | supporting the titanium compound (A-4) represented by this.
(M ¹ ) _a (Mg) _b (R ¹ ) _c (R ² ) _d (OR ³ ) _e (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 and R ² each have 2 to 20 carbon atoms. R ³ is a hydrocarbon group having 1 to 20 carbon atoms, and a, b, c, d, and e are real numbers that satisfy the following relationship: 0 ≦ a, 0 <b , 0 ≦ c, 0 ≦ d, 0 ≦ e, 0 <c + d, 0 ≦ e / (a + b) ≦ 2, f × a + 2b = c + d + e (where f is the valence of M ¹ ))
H _h SiCl _i R ⁴ _{(4- (h + i))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and h and i are real numbers satisfying the following relationship: 0 <h, 0 <i, 0 <h + i ≦ 4)
Ti (OR ⁵ ) _j X _(4-j) (3)
(In the formula, j is a real number of 0 or more and 4 or less, R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)

First, the organomagnesium compound (A-1) will be described. (A-1) is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but includes all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds Is. The symbols a, b, c, d and e in the general formula (1) satisfy the relational expression: f × a + 2b = c + d + e, which indicates the stoichiometry between the valence of the metal atom and the substituent.
In the above formulae, the hydrocarbon groups represented by R ¹ to R ² are each an alkyl group, a cycloalkyl group or an aryl group, for example, methyl, ethyl, propyl, butyl, propyl, hexyl, octyl, decyl, cyclohexyl , A phenyl group, etc., preferably R ¹ and R ² are each an alkyl group. When a> 0, as the metal atom M ¹ , metal atoms other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table can be used. For example, lithium, sodium Potassium, beryllium, zinc, boron, aluminum and the like, and aluminum, boron, beryllium, and zinc are particularly preferable.

No particular limitation on the ratio b / a of magnesium to metal atom M ^1, but more preferably preferably 0.1 to 30, 0.5 to 10. Further, when a certain organomagnesium compound in which a = 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 (1), when a = 0, R ¹ and R ² are recommended to be any one of the following three groups (1), (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 R ¹ and R ² both 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 numbers, preferably R ¹ is an alkyl group having 2 or 3 carbon atoms, and R ² is an alkyl group having 4 or more carbon atoms. thing.
(3) At least one of R ¹ and R ² is a hydrocarbon group having 6 or more carbon atoms, preferably an alkyl group in which the sum of carbon atoms contained in R ¹ and R ² is 12 or more.

Hereinafter, these groups are specifically shown.
As the secondary or tertiary alkyl group having 4 to 6 carbon atoms in (1), 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 ethyl 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. The inert hydrocarbon solvent in the present invention includes aliphatic hydrocarbons such as pentane, hexane and heptane, aromatic hydrocarbons such as benzene and toluene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. .

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.

In the present invention, the synthesis method of (A-1) is not particularly limited, but from the general formulas R ¹ MgX and R ¹ ₂ Mg (R ¹ has the above-mentioned meaning and X is a halogen atom). And an organometallic compound belonging to the group consisting of the general formulas M ¹ R ² _f and M ¹ R ² _(f-1) H (M ¹ , R ² and f are as defined above) In an inert hydrocarbon solvent, the reaction is carried out at a temperature of 25 ° C. or more and 150 ° C. or less, and if necessary, an alcohol having a hydrocarbon group represented by R ³ (R ³ has the above-mentioned meaning) or A method of reacting with an alkoxymagnesium compound having a hydrocarbon group represented by R ³ and / or an alkoxyaluminum compound that is soluble in an inert hydrocarbon solvent is preferred.

  Among these, when reacting an organomagnesium compound soluble in an inert hydrocarbon solvent with an alcohol, the order of the reaction is not particularly limited, and a method of adding alcohol to the organomagnesium compound, organomagnesium in the alcohol Either a method of adding a compound or a method of adding both at the same time can be used. 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 has an The molar composition ratio e / (a + b) is 0 ≦ e / (a + b) ≦ 2, and preferably 0 ≦ e / (a + b) <1.

Next, the chlorinating agent (A-2) will be described. (A-2) is represented by the following general formula (2). At least one is a silicon chloride compound having a Si—H bond.
H _h SiCl _i R ⁴ _{(4- (h + i))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and h and i are real numbers satisfying the following relationship: 0 <h, 0 <i, 0 <h + i ≦ 4)
The hydrocarbon group represented by R ⁴ in the general formula (2) is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group such as methyl, ethyl, propyl, 1-methylethyl. , Butyl, pentyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Among them, an alkyl group having 1 to 10 carbon atoms is preferable, and 1 to 1 carbon atoms such as methyl, ethyl, propyl and 1-methylethyl groups are preferable. More preferred is an alkyl group of 3. H and i are numbers greater than 0 satisfying the relationship of h + i ≦ 4, and i is preferably 2 or more and 3 or less.

These compounds include HSiCl ₃ , HSiCl ₂ CH ₃ , HSiCl ₂ C ₂ H ₅ , HSiCl ₂ (C ₃ H ₇ ), HSiCl ₂ (2-C ₃ H ₇ ), 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 SiCl (CH ₃ ), H ₂ SiCl (C ₂ H ₅ ), HSiCl (CH ₃ ) ₂ , HSiCl (C ₂ H ₅ ) ₂ , HSiCl ( CH ₃ ) (2-C ₃ H ₇ ), HSiCl (CH ₃ ) (C ₆ H ₅ ), HSiCl (C ₆ H ₅ ) _{2 and the} like, and these compounds or these compounds A silicon chloride compound composed of a mixture of two or more selected from the above is used. Among these, trichlorosilane, monomethyldichlorosilane, dimethylchlorosilane, and ethyldichlorosilane are preferable, and trichlorosilane and monomethyldichlorosilane are more preferable.

  Next, the reaction between (A-1) and (A-2) will be described. In the reaction, (A-2) is preliminarily treated with an inert hydrocarbon solvent, chlorinated hydrocarbons such as 1,2-dichloroethane, o-dichlorobenzene and dichloromethane, or ether-based media such as diethyl ether and tetrahydrofuran, or these It is preferable to use after diluting with a mixed medium, and an inert hydrocarbon solvent is more preferable in view of the performance of the catalyst. Although there is no restriction | limiting in particular in the reaction ratio of (A-1) and (A-2), The silicon atom contained in (A-2) with respect to 1 mol of magnesium atoms contained in (A-1) is 0.01. It is preferably 100 mol or less, more preferably 0.1 mol or more and 10 mol or less.

  The reaction method of (A-1) and (A-2) is not particularly limited, and a method of simultaneous addition in which (A-1) and (A-2) are reacted while being simultaneously introduced into the reactor, A method in which (A-1) is introduced into the reactor after A-2) is charged in the reactor in advance, or (A-2) in the reactor after (A-1) is charged in the reactor in advance. Although any method of the method of introducing may be sufficient, the method of introducing (A-1) into a reactor after charging (A-2) into a reactor in advance is preferable. The carrier (A-3) obtained by the above reaction is preferably separated by filtration or decantation and then thoroughly washed with an inert hydrocarbon solvent to remove unreacted products or by-products. .

  Although there is no restriction | limiting in particular about the reaction temperature of (A-1) and (A-2), It is preferable that it is 25 to 150 degreeC, It is more preferable that it is 40 to 150 degreeC, 50 degreeC More preferably, it is 150 degrees C or less. In the method of simultaneous addition in which (A-1) and (A-2) are simultaneously introduced into the reactor and reacted, the temperature of the reactor is adjusted to a predetermined temperature in advance, The reaction temperature is preferably adjusted to the predetermined temperature by adjusting the temperature to the predetermined temperature. In the method in which (A-1) is introduced into the reactor after (A-2) is charged in the reactor in advance, the temperature of the reactor charged with the silicon chloride compound is adjusted to a predetermined temperature, and the organomagnesium The reaction temperature is preferably adjusted to a predetermined temperature by adjusting the temperature in the reactor to a predetermined temperature while introducing the compound into the reactor. In the method of introducing (A-2) into the reactor after charging (A-1) into the reactor in advance, the temperature of the reactor charged with (A-1) is adjusted to a predetermined temperature, and (A The reaction temperature is adjusted to a predetermined temperature by adjusting the temperature in the reactor to a predetermined temperature while introducing -2) into the reactor.

The reaction of (A-1) and (A-2) can also 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 oxides (ii) Inorganic carbonates, silicates, sulfates (iii) Inorganic hydroxides (iv) Inorganic halides (v) Double salts, solid solutions or mixtures comprising (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) 2SiO ₄ ] , Aluminum silicate [Al ₂ O ₃ .SiO ₂ ], calcium carbonate, magnesium chloride, magnesium iodide, and the like are preferable, and silica, silica / alumina, and magnesium chloride are particularly preferable. 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, the titanium compound (A-4) will be described. In the present invention, (A-4) is a titanium compound represented by the following general formula (3).
Ti (OR ⁵ ) _j X _(4-j) (3)
(Wherein j is a real number of 0 or more and 4 or less, R ⁶ is a hydrocarbon group of 1 to 20 carbon atoms, and X is a halogen atom.)
Examples of the hydrocarbon group represented by R ⁵ 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 represented by X include chlorine, bromine and iodine, with chlorine being preferred. (A-4) selected from the above can be used as a mixture of two or more.

Although there is no restriction | limiting in particular in the usage-amount of (A-4), 0.01-20 is preferable by molar ratio with respect to the magnesium atom contained in a support | carrier (A-3), and 0.05-10 is especially preferable.
Although there is no restriction | limiting in particular about the reaction temperature of (A-4), It is preferable to carry out in 25 to 150 degreeC.
In the present invention, there is no particular limitation on the method of supporting (A-4) with respect to (A-3), and there is a method of reacting excess (A-4) with (A-3) or a third component. A method of efficiently supporting (A-4) by use may be used, but a method of supporting by (A-4) and an organometallic compound (A-5) is preferred.

Next, the organometallic compound (A-5) will be described. As (A-5), what is represented by the following general formula (4) and general formula (5) is preferable.
(M ¹ ) _a (Mg) _b (R ¹ ) _c (R ² ) _d Y _e (4)
(Wherein M ¹ , R ¹ , R ² , a, b, c, d, e are as described above, Y is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁶ , R ⁷ , —SR ⁸ (wherein R ⁶ , R ⁷ and R ⁸ represent a hydrocarbon group having 1 to 20 carbon atoms. When e is 2 or more, Y may be different from each other), any one of β-keto acid residues, and a, b, c, d, and e are real numbers satisfying the following relationship: 0 ≦ a, 0 <b, 0 ≦ c, 0 ≦ d, 0 ≦ e , 0 <c + d, 0 ≦ e / (a + b) ≦ 2, f × a + 2b = c + d + e (where f is the valence of M ¹ ))
M ² R ⁹ _k Q _(m−k) (5)
(Wherein M ² is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12, Group 13 of the Periodic Table, R ⁹ is a hydrocarbon group having 1 to 20 carbon atoms, and Q is OR ¹⁰ , OSiR ¹¹ R ¹² R ¹³ , NR ¹⁴ R ¹⁵ , SR ¹⁶ and a group belonging to the group consisting of halogen, R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ are hydrogen atoms Or a hydrocarbon group, k is a real number greater than 0, and m is the valence of M ² )

Hereinafter, the organometallic compounds represented by the general formula (4) and the general formula (5) are referred to as (A-5a) and (A-5b), respectively.
First, (A-5a) will be described.
The amount of (A-5a) used is preferably 0.1 or more and 10 or less in terms of the molar ratio of magnesium atoms contained in (A-5a) to titanium atoms contained in (A-4). More preferably, it is 5 or less. Although there is no restriction | limiting in particular about the temperature of reaction with (A-4) and (A-5a), It is preferable that it is -80 degreeC or more and 150 degrees C or less, and it is the range of -40 degreeC or more and 100 degrees C or less. Further preferred.

Although there is no restriction | limiting in particular about the density | concentration at the time of use of (A-5a), It is preferable that it is 0.1 mol / l or more and 2 mol / l or less on the basis of the magnesium atom contained in (A-5a). More preferably, it is 5 mol / l or more and 1.5 mol / l or less. In addition, it is preferable to use an inert hydrocarbon solvent for the dilution of (A-5a).
There is no restriction | limiting in particular in the addition order of (A-4) and (A-5a) with respect to (A-3), (A-5a) is added following (A-4), (A-5a) is followed. (A-4) and (A-4) and (A-5a) can be added at the same time, but (A-4) and (A-5a) can be added simultaneously. The method of adding is preferable. The reaction between (A-4) and (A-5a) is carried out in an inert hydrocarbon solvent, but it is preferable to use an aliphatic hydrocarbon solvent such as hexane or heptane. The catalyst thus obtained is used as a slurry solution using an inert hydrocarbon solvent.

Next, (A-5b) will be described.
In the above general formula (5), M ² is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12, Group 13 of the Periodic Table, for example, lithium, sodium, potassium, beryllium, magnesium , Boron, aluminum, zinc and the like, magnesium, boron and aluminum are preferable. The hydrocarbon group represented by R ⁹ 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. It is preferably a group. Q represents a group belonging to the group consisting of OR ¹⁰ , OSiR ¹¹ R ¹² R ¹³ , NR ¹⁴ R ¹⁵ , SR ¹⁶ and halogen, and R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ Is a hydrogen atom or a hydrocarbon group, and Q is preferably a halogen atom. As the compound name of (A-5b), 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 bromide , Diethyla Minium ethoxide, ethylaluminum dichloride, ethylaluminum sesquichloride, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, etc. preferable. Moreover, it is also possible to mix and use these compounds. k is a real number larger than 0, and is preferably a real number larger than 0.5.

The amount of (A-5b) used is preferably 0.1 or more and 10 or less in terms of a molar ratio of M ³ atoms contained in (A-5b) to titanium atoms contained in (A-4). More preferably, it is 5 or more and 5 or less. Although there is no restriction | limiting in particular about the temperature of reaction of (A-4) and (A-5b), It is preferable that it is 20 to 150 degreeC, and it is more preferable that it is 40 to 100 degreeC.
No particular limitation is imposed on the concentration at the time of use (A-5b), preferably not more than (A-5b) INCLUDED ^{M 2} atomic basis in 0.1 mol / l or more 2 mol / l, 0 More preferably, it is 5 mol / l or more and 1.5 mol / l or less. In addition, it is preferable to use an inert hydrocarbon solvent for the dilution of (A-5b).

  There is no restriction | limiting in particular in the addition method of (A-4) and (A-5b) with respect to (A-3), First, (A-4) is added, and this is followed by the method of adding (A-5b) First, (A-5b) is added, and then either (A-4) is added, or (A-4) and (A-5b) are added simultaneously. However, it is preferable to add (A-5b) first and then add (A-4). The reaction between (A-4) and (A-5b) is carried out in an inert hydrocarbon solvent, but it is preferable to use an aliphatic hydrocarbon solvent such as hexane or heptane. The catalyst thus obtained is used as a slurry solution using an inert hydrocarbon solvent.

When (A-5b) is used, (A-3) is reacted with alcohol in advance before adding (A-4) and (A-5b) to (A-3). Further, it is preferable to react with (A-5b).
As the alcohol, those having 1 to 10 carbon atoms are preferable, and specifically, methanol, ethanol, propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-methyl. -2-propanol, 1-pentanol, 1-hexanol, 1-octanol, 2-ethyl-1-hexanol, decanol, and the like. As the alcohol, those having 2 to 6 carbon atoms are more preferable, and ethanol, propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-methyl-2-propanol, 1 More preferred are pentanol and 1-hexanol. Although there is no restriction | limiting in particular about the usage-amount of alcohol, It is preferable that it is 0.01-1 in molar ratio with respect to the magnesium atom contained in (A-3), and it is 0.05-0.5. Further preferred. Although there is no restriction | limiting in particular about the density | concentration at the time of use of alcohol, It is preferable to use it diluting 0.1M or more and 2M or less using an inert hydrocarbon solvent. Although there is no restriction | limiting in particular about the temperature of reaction with (A-3) and alcohol, It is preferable that it is 25 to 150 degreeC, and it is more preferable that it is 40 to 80 degreeC.

The reaction between (A-3) and (A-5b) after reacting with alcohol will be described. Although there is no restriction | limiting in particular about the usage-amount of (A-5b), It is preferable that it is 0.1 or more and 10 or less by molar ratio with respect to the used alcohol, and it is still more preferable that it is 0.5 to 5 times. No particular limitation is imposed on the concentration at the time of use (A-5b), preferably not more than (A-5b) INCLUDED ^{M 2} atomic basis in 0.1 mol / l or more 2 mol / l, 0 More preferably, it is 5 mol / l or more and 1.5 mol / l or less. In addition, it is preferable to use an inert hydrocarbon solvent for the dilution of (A-5b). Although there is no restriction | limiting in particular about the temperature of reaction with (A-3) and (A-5b) after making it react with alcohol, It is preferable that it is 25 to 150 degreeC, and it is 40 to 80 degreeC. More preferably it is.

Next, the organometallic compound component [B] in the present invention will be described. The solid catalyst component [A] of the present invention becomes a highly active polymerization catalyst when combined with the organometallic compound component [B]. The organometallic compound component [B] is preferably a compound containing a metal belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, particularly organoaluminum compounds and / or Or an organomagnesium compound is preferable.
As the organoaluminum compound, a compound represented by the following general formula (6) is preferably used alone or in combination.
AlR ¹⁷ _n Z _(3-n) (6)
Wherein R ¹⁷ is a hydrocarbon group having 1 to 20 carbon atoms, Z is a group belonging to the group consisting of hydrogen, halogen, alkoxy, allyloxy and siloxy groups, and n is a number of 2 to 3. In the above general formula 6, the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹⁷ includes aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons. Trialkylaluminum such as aluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum, tripentylaluminum, tri (3-methylbutyl) aluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, Diethylaluminum chloride, ethylaluminum Aluminum halide compounds such as mudichloride, bis (2-methylpropyl) aluminum chloride, ethylaluminum sesquichloride, diethylaluminum bromide, alkoxyaluminum compounds such as diethylaluminum ethoxide, bis (2-methylpropyl) aluminum butoxide, dimethylhydrosiloxy Siloxyaluminum compounds such as aluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminum diethyl and mixtures thereof are preferred, and trialkylaluminum compounds are particularly preferred.

The organomagnesium compound is preferably an organomagnesium compound that is soluble in an inert hydrocarbon solvent represented by the following general formula (1).
(M ¹ ) _a (Mg) _b (R ¹ ) _c (R ² ) _d (OR ³ ) _e (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 and R ² each have 2 or more carbon atoms. A hydrocarbon group having 20 or less, R ³ is a hydrocarbon group having 1 to 20 carbon atoms, and a, b, c, d and e are real numbers satisfying the following relationship: 0 ≦ a, 0 < b, 0 ≦ c, 0 ≦ d, 0 ≦ e, 0 <c + d, 0 ≦ e / (a + b) ≦ 2, f × a + 2b = c + d + e (where f is the valence of M ¹ ))

This organomagnesium compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but encompasses all dialkylmagnesium compounds and complexes of this compound with other metal compounds. is there. Since this organomagnesium compound is preferably a compound having high solubility in an inert hydrocarbon solvent, b / a is preferably 0.5 or more and 10 or less, and more preferably a compound in which M ¹ is aluminum.

  The method for adding the solid catalyst component [A] and the organometallic compound component [B] to the polymerization system under the polymerization conditions is not particularly limited, and both may be added separately to the polymerization system. You may add in a polymerization system, after making both react. Moreover, there is no restriction | limiting in particular in the ratio of both to combine, but it is preferable that organometallic compound [B] is 1 to 3000 millimoles with respect to 1 g of solid catalyst component [A].

In the present invention, a polyethylene resin composition based on a Ziegler-based catalyst achieves desired cleanliness, rough skin, extruding properties such as draw-down properties, impact resistance, and a specific numerical range by a specific polymerization method. It is necessary to have a polyethylene composition having the following physical properties.
In the present invention, the polyethylene resin contained in the polyethylene resin composition for high-purity chemical containers is a polyethylene resin composition produced by a multistage polymerization method comprising at least a low molecular weight component and a high molecular weight component.

  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 ethylene is homopolymerized or ethylene and olefin are copolymerized by a multistage polymerization apparatus in which a plurality of polymerization vessels are usually connected in series. In the present invention, an ethylene polymer having a low molecular weight component of Mw of 5000 or more and 100,000 or less is produced in at least one polymerization vessel, and a high molecular weight component of Mv is 1 million or more and 4 million in at least one polymerization vessel. It is necessary to produce an ultra high molecular weight ethylene polymer that is: In addition, in a polymerization vessel other than the polymerization vessel for producing these low molecular weight components and high molecular weight components, an ethylene polymer having a molecular weight of Mw of 5000 or more and Mv of 4 million or less can be produced. In the present invention, the polymerization vessel for producing the low molecular weight component is not particularly limited, and may be a first-stage polymerization vessel, an intermediate polymerization vessel, or a final-stage polymerization vessel. It may be a multi-polymerizer of two or more stages, but is preferably a first-stage or intermediate polymerizer. There is no particular limitation on the polymerization vessel for generating the high molecular weight component, which may be a first-stage polymerization vessel, an intermediate polymerization vessel, or a final-stage polymerization vessel, A multi-polymerizer having two or more stages may be used, but an intermediate or final-stage polymerizer is preferable.

  The low molecular weight component of the polyethylene resin contained in the polyethylene resin composition for high-purity chemical containers in the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. An ethylene homopolymer or a copolymer of ethylene and an α-olefin having 4 to 8 carbon atoms is more preferable, and an ethylene homopolymer is more preferable.

  Next, the molecular weight of the low molecular weight component of the polyethylene resin composition will be described. In the present invention, the molecular weight of the low molecular weight polyethylene resin is 3 g / 10 min or more and 50 g / 10 min or less in terms of melt flow rate (MFR) measured according to JIS K7210-1999, code D, and 5 g / 10 min or more. It is preferably 50 g / 10 min or less, more preferably 10 g / 10 min or more and 50 g / 10 min or less, more preferably 20 g / 10 min or more and 45 g / 10 min or less, more preferably 30 g / 10 min or more. It is particularly preferred that it is 45 minutes or less. When the melt flow rate is 3 g / 10 min or more, the molecular weight distribution becomes wide and the moldability is good, such as rough skin is less likely to occur. By setting the melt flow rate to 50 g / 10 min or less, the generation of particles can be almost suppressed and the cleanness can be reduced. In addition to no reduction, molding defects due to drawdown when molding large molded products are less likely to occur.

The density of the low molecular weight component of the polyethylene resin in the present invention will be described. In the present invention, the density of the low molecular weight component of the polyethylene resin composition, 974kg / ^{m 3} or less 960 kg / ^{m 3} or more for the density of the low molecular weight component in has been determined the present invention in accordance with JIS K7112-1999 it is preferably, and more preferably not more than 963kg / ^{m 3} or more 970 kg / ^{m 3.} The density is defined by the amount of comonomer introduced into the polyethylene resin, and the density decreases as the amount of comonomer increases. However, by limiting the comonomer amount by setting the density to 960 kg / m ³ or more, the cleanliness increases dramatically.

  The high molecular weight component of the polyethylene resin contained in the polyethylene resin composition for high-purity chemical containers in the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. More preferably, it is a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms, and is a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms. More preferably it is. In the present invention, the mass fraction of the high molecular weight component to the polyethylene resin composition is 0.40 or more and 0.46 or less, preferably 0.40 or more and 0.43 or less. When the MFR of the composition is fixed, if the mass fraction becomes small, the molecular weight of the high molecular weight component becomes relatively large, which causes the generation of gel. On the other hand, when the mass fraction is large, the difference in molecular weight between the high molecular weight component and the low molecular weight component is small, and moldability such as rough skin is deteriorated. When the mass fraction is 0.40 or more, no gel is generated. When the mass fraction is 0.46 or less, the molecular weight distribution is wide, and the moldability is good.

Next, the density of the polyethylene resin composition in the present invention will be described. Density of 955 kg / ^{m 3} or more 965 kg / ^{m 3} or less of the resin composition in the present invention. If the density of the polyethylene resin composition is 955 kg / m ³ or more, the low-density component to be eluted is sufficiently small, and if the density is 965 kg / m ³ or less, the long-term characteristics of the polyethylene resin composition are sufficiently high.

  Next, the molecular weight of the polyethylene resin composition in the present invention will be described. In the present invention, the molecular weight of the polyethylene resin composition is 0.4 g / 10 min or more and 1.0 g / 10 min or less as a melt flow rate (MFR) measured according to JIS K7210-1999, code T. If the MFR of the polyethylene resin composition is 0.4 g / 10 min or more, the moldability is good, and if the MFR is 1.0 g / 10 min or less, the high purity produced using the resin composition The mechanical properties of the chemical container, such as ESCR and impact strength, are sufficiently high. The MFR of the polyethylene resin composition is preferably 0.45 g / 10 min to 0.9 g / 10 min, more preferably 0.5 g / 10 min to 0.9 g / 10 min, It is especially preferable that it is 0.55 g / 10 min or more and 0.85 g / 10 min or less.

  Next, in the present invention, the molecular weight of 1000 or less as measured by gel permeation chromatography (GPC) is preferably 0.5 w% or less, more preferably 0.4 w% or less, and even more preferably 0.3 w% or less. The amount indicates the amount of low molecular weight components and wax contained in polyethylene, and the low molecular weight components and wax are eluted in high-purity chemicals to cause fine particles and deteriorate cleanliness.

  In this invention, an additive is not included substantially. “Substantially free” means that no additive is intentionally added. Generally, a polyethylene resin is added with a heat stabilizer for preventing thermal deterioration and a lubricant for neutralization and slipperiness improvement. In the present invention, additives that can be eluted in high-purity chemicals include all additives that can be eluted in high-purity chemicals. Specifically, hindered phenols, sulfurs, etc. Examples include heat stabilizers such as acid esters and antioxidants, weathering stabilizers such as benzotriazoles, hindered amines, triazines, and benzophenones, UV absorbers, antistatic agents, lubricants, and antiblocking agents. The feature is that these additives are not added. On the other hand, pigments, light-shielding agents, etc. that do not elute into high-purity chemicals can be used as long as the desired effects are not impaired.

As described above, the expected cleanliness, rough skin, and extrudability are achieved only when the MFR, density, and resin composition mass fraction of these low molecular weight components are within the specified ranges and do not substantially contain additives. can do.
In order to mold the resin composition of the present invention, general molding methods, blow molding, injection molding, injection blow molding, sheet molding, vacuum molding, extrusion molding, rotational molding and the like can be considered, but blow molding is preferable.

The present invention will be described based on examples.
First, the measurement method used in the examples will be described.
1) Melt flow rate (MFR): JIS K7210-1999, the low molecular weight component of polyethylene resin was measured according to Condition Code D, and the polyethylene resin composition was measured according to Condition Code T.
2) Density: Measured in accordance with JIS K7112-1999 (Method D). The strand extruded from the standard melt indexer at 190 ° C. was cooled, immersed in a 120 ° C. oil bath for 1 hour in a nitrogen atmosphere, cooled in a constant temperature room at 23 ° C. for 1 hour, and then measured with a density gradient tube.
3) Mass fraction: It was adjusted by controlling the mass of ethylene added to the polymerization vessel per unit time.

4) Gel permeation chromatography (GPC): Waters GPCV2000 type, using 1,2,4-trichlorobenzene at 140 ° C. as a solvent, flow rate 1.0 ml / min, sample concentration 20 mg / 15 ml, injection The amount was 413 μl, the sample dissolution temperature was 140 ° C., and the sample dissolution time was 2 hours. As the column, one Shodex UT-807 manufactured by Showa Denko KK and two TSK-GEL GMHHR-H (S) HT manufactured by Tosoh Corporation were connected in series.

5) Roughness of the skin: using a Plako SB55 blow molding machine, the die diameter is 62φ / 61φ, the temperature is set to cylinders 1, 2, 3, adapters, dice 1, 2 in order of 180, 200, 220, 220, 220, 180 ° C. The die head heater was turned off. The parison was extruded with a clearance of 0.5 mm and a screw rotation speed of 75 rpm, and the rough surface of the parison surface was observed. A sample having a smooth parison surface was marked with ◯, a sample with fine irregularities was marked with △, and a sample with large stripes was marked with ×.

6) Formability: Using a SB55 blow molding machine manufactured by Plako, the die diameter is 47φ / 46φ, the temperature is set to cylinders 1, 2, 3, adapters, dies 1, 2, and die head in the order of 180, 200, 200, 200, 200, 200, 200 ° C. A 2L round bottle was molded to confirm moldability such as bottle shapeability, bottle pinch-off fusing property, and fleshiness. As for the fleshiness, ◯ indicates that the meat circumference is good and the bottle bottom corner has a sufficient thickness, and △ indicates that the meat circumference is poor and the bottle bottom corner thickness is thin.

7) Measurement of cleanness (i) Bottle molding Using a blow molding machine with a 50 mm diameter screw, a round container having a capacity of 200 ml was molded at a cylinder temperature of 180 ° C and a mold temperature of 20 ° C.
(Ii) Measurement of the number of leached fine particles 100 ml of ultrapure water (Trepure LV-10T (manufactured by Toray Industries, Inc.) (registered trademark)) was put into a molded container, and washed with shaking for 15 seconds to be drained. This shaking washing was repeated 5 times. The container was again filled with 100 ml of ultrapure water and stored as it was at room temperature for 4 weeks. After 4 weeks, 5 ml was collected from this filling water, and the number of fine particles of 0.2 μm or more leached into it was measured with a particle counter (KL-22 (manufactured by Lion Co., Ltd.)). The number of fine particles contained in water can be obtained by the following equation (7), which is defined as the cleanness.

When the degree of cleanness was 500 pieces / ml or less, the judgment was “good”, and when the degree of cleanliness was more than 500 pieces / ml and 750 pieces / ml or less, the judgment was made Δ.
8) Additive extraction analysis: The extruded polyethylene composition pellets were frozen and ground. Additives were extracted from 10 g of the polyethylene pulverized product thus obtained using a Soxhlet extractor. As the extraction solvent, 720 ml of chloroform was used. Extraction was performed by refluxing for 8 hours. The chloroform extract was concentrated to 20 ml and subjected to qualitative and quantitative HPLC (LC-10A, manufactured by Shimadzu Corporation). In addition, the qualitative and quantitative determination of the additive was performed using a sample. The column was μ-Porasil, the developing solvent was hexane, and detection was performed with UV (210 nm).

[Example 1]
(1) Synthesis of titanium catalyst 4 liters of trichlorosilane as a 2 mol / liter heptane solution was charged into a 15 liter reactor sufficiently purged with nitrogen, kept at 65 ° C. with stirring, and the composition formula AlMg ₆ (C ₂ H ₅ ) ₃ (C ₄ H ₉ ) _6.4 (OC ₄ H ₉ ) 9 liters of a heptane solution of an organic magnesium component represented by _5.6 (6.5 mol in terms of magnesium) was added over 1 hour, and The reaction was carried out at 65 ° C. for 1 hour with stirring. After completion of the reaction, the supernatant was removed and washed 4 times with 7 liters of hexane to obtain a solid material slurry. This solid was separated, dried and analyzed. As a result, it contained 7.42 mmol of magnesium per gram of the solid.
The amount of the slurry containing 500 g of solid was adjusted to 13 liters with hexane, and reacted with 0.93 liter of hexane solution of 1 mol / liter of butanol at 50 ° C. for 1 hour with stirring. After completion of the reaction, the supernatant was removed and washed once with 7 liters of hexane. This slurry was kept at 50 ° C., and 0.84 liter of hexane solution of 1 mol / liter of diethylaluminum chloride was added with stirring and reacted for 1 hour. After completion of the reaction, the supernatant was removed and washed twice with 7 liters of hexane. The slurry was kept at 50 ° C., 60 ml of diethylaluminum chloride 1 mol / liter hexane solution and 60 ml of hexane solution 1 mol / liter titanium tetrachloride were added and reacted for 2 hours. After completion of the reaction, the supernatant was removed and the solid catalyst was isolated and washed with hexane until no free halogen was detected. The solid catalyst had 0.6 wt% titanium.

(2-1) Polymerization of polyethylene resin composition First, in order to produce a low molecular weight component in the first stage polymerization, a stainless polymerizer 1 having a reaction volume of 300 liters was used, with a polymerization temperature of 83 ° C and a polymerization pressure of 1 MPa. Under the conditions, the above catalyst was introduced at a rate of 4.2 mmol / hr in terms of Ti atom, triethylaluminum at 20 mmol / hr in terms of Al atom, and hexane at a rate of 40 liter / hr. Hydrogen was used as a molecular weight regulator, and polymerization was carried out by supplying the hydrogen so that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) with respect to the sum of ethylene and hydrogen was 54 mol%. The melt flow rate (code D) of the low molecular weight component produced in the polymerization vessel 1 was 40 g / 10 min, and the density was 966 kg / m ³ .
The polymer slurry solution in the polymerization vessel 1 is led to a flash drum having a pressure of 0.1 MPa and a temperature of 75 ° C. After separating unreacted ethylene and hydrogen, the pressure is increased by a slurry pump to a stainless polymerizer 2 having a reaction volume of 250 liters. Introduced. In the polymerization vessel 2, triethylaluminum was introduced at a rate of 7.5 mmol / hr and hexane was introduced at a rate of 40 l / hr under the conditions of a temperature of 80 ° C. and a pressure of 0.2 MPa. To this, ethylene, hydrogen, 1-butene, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 2.6 mol%, and the sum of ethylene and 1-butene The gas phase molar concentration of 1-butene (1-butene / (ethylene + 1-butene)) was introduced so as to be 1.5 mol%, and the mass of the low molecular weight component produced in the polymerizer 1 and the polymerizer 2 Ratio of mass of high molecular weight component generated in polymerizer 2 to sum of mass of generated high molecular weight component (mass of high molecular weight component generated in polymerizer 2 / (mass of low molecular weight component generated in polymerizer 1+ The high molecular weight component is polymerized so that the mass of the high molecular weight component produced in the polymerization vessel 2 is 0.42, and the melt flow rate (code T) is 0.45 g / 10 min and the density is 957 kg / m ³ of polyethylene. A resin composition was produced.

(3-1) Production of polyethylene resin composition The polyethylene resin composition produced as described above was used with a twin-screw extruder having a cylinder diameter of 44 mm (TEX44HCT-49PW-7V manufactured by Nippon Steel Co., Ltd.). Extrusion was carried out while kneading at an extrusion rate of 35 kg / hour to obtain a polyethylene resin composition.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and the cleanness was satisfactory.
When the additive extraction analysis was performed on the extruded polyethylene resin composition, no additive was detected.
As for rough skin, the parison surface was smooth. Formability was slightly inferior, and the bottom corner was thin.

[Example 2]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-2) Polymerization of polyethylene resin composition Polymerization was carried out in the polymerization vessel 1 in the same manner as in Example 1. The melt flow rate (code D) of the low molecular weight component produced in the polymerization vessel 1 was 40 g / 10 min, and the density was 966 kg / m ³ .
In the polymerization vessel 2, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 3.3 mol%, and the gas phase mole of 1-butene relative to the sum of ethylene and 1-butene. Polymerizer 2 with a concentration (1-butene / (ethylene + 1-butene)) of 1.3 mol%, the sum of the mass of the low molecular weight component produced in polymerizer 1 and the mass of the high molecular weight component produced in polymerizer 2 The ratio of the mass of the high molecular weight component produced in (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) is 0. Polymerization was carried out in the same manner as in Example 1 except that the high molecular weight component was polymerized so as to be .45, and the resulting polyethylene resin composition had a melt flow rate (code T) of 0.45 g / 10 min. Was 957 kg / m ³ .
(3-2) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the polyethylene resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.4%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, fine irregularities were observed on the parison surface. Formability was slightly inferior, and the bottom corner was thin.

[Example 3]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-3) Polymerization of polyethylene resin composition Polymerization was carried out in the polymerization vessel 1 in the same manner as in Example 1. The melt flow rate (code D) of the low molecular weight component produced in the polymerization vessel 1 was 40 g / 10 min, and the density was 966 kg / m ³ .
The gas phase molar concentration of hydrogen (hydrogen / (ethylene + hydrogen)) with respect to the sum of ethylene and hydrogen is 3.3 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 1.4 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) was 0.42. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.59 g / 10 min and a density of 958 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-3) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1, using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for the rough skin, the parison surface was smooth and the moldability was satisfactory.

[Example 4]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-4) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 49 mol% Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 20 g / 10 minutes, and the density was 964 kg / m ³ .
Further, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 3.0 mol%, and the gas phase molar concentration of 1-butene relative to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 1.4 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) was 0.42. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.46 g / 10 min and a density of 957 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-4) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, fine irregularities were observed on the parison surface. Formability was slightly inferior, and the bottom corner was thin.

[Example 5]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-5) Polymerization of polyethylene resin composition Polymerization was carried out in the polymerization vessel 1 in the same manner as in Example 1. The melt flow rate (code D) of the low molecular weight component produced in the polymerization vessel 1 was 40 g / 10 min, and the density was 966 kg / m ³ .
Further, the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 4.5 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 1.4 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) was 0.42. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.67 g / 10 min and a density of 957 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-5) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, the parison surface was smooth and had no problem, and there was no problem with moldability.

[Example 6]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-6) Polymerization of polyethylene resin composition Polymerization was carried out in the polymerization vessel 1 in the same manner as in Example 1. The melt flow rate (code D) of the low molecular weight component produced in the polymerization vessel 1 was 40 g / 10 min, and the density was 966 kg / m ³ .
Further, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 3.0 mol%, and the gas phase molar concentration of 1-butene relative to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 1.4 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) was 0.42. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.78 g / 10 min and a density of 957 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-6) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, the parison surface was smooth and had no problem, and there was no problem with moldability.

[Comparative Example 1]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-7) Polymerization of polyethylene resin composition Polymerization was carried out in the polymerization vessel 1 in the same manner as in Example 1. The melt flow rate (code T) of the low molecular weight portion produced in the polymerization vessel 1 was 40 g / 10 minutes, and the density was 966 kg / m ³ .
In addition, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 2.5 mol%, and the gas phase molar concentration of 1-butene relative to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 2.2 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) is 0.45. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) MFR of 0.35 g / 10 min and a density of 957 kg. / M ³ polyethylene tree A fat composition was produced.
(3-7) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.4%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, a large striped pattern was generated on the parison surface. Formability was slightly inferior, and the bottom corner was thin.

[Comparative Example 2]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-8) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 49 mol% Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 20 g / 10 minutes, and the density was 964 kg / m ³ .
Further, the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 2.9 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 0.2 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2 The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerizer 2 / (the mass of the low molecular weight component produced in the polymerizer 1 + the mass of the high molecular weight component produced in the polymerizer 2)) is 0.45. Except that the high molecular weight component was polymerized, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.35 g / 10 min and a density of 956 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-8) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.3%, and there was no problem with cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, a large striped pattern was generated on the parison surface. Formability was slightly inferior, and the bottom corner was thin.

[Comparative Example 3]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-9) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 40 mol% Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 5 g / 10 minutes, and the density was 963 kg / m ³ .
In addition, the gas phase molar concentration of hydrogen relative to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 13.8 mol%, and the gas phase molar concentration of 1-butene relative to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 0.8 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerization vessel 2 / (the mass of the low molecular weight component produced in the polymerization vessel 1 + the mass of the high molecular weight component produced in the polymerization vessel 2)) is 0.50. Except that the high molecular weight component was polymerized, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 1.50 g / 10 min and a density of 957 kg / min. m ³ polyethylene resin set A composition was produced.
(3-9) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.2%, and the cleanness was satisfactory.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
The surface roughness of the parison surface was smooth, but the drawdown was severe and a large molded product could not be obtained.

[Comparative Example 4]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-10) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 64 mol%. Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 180 g / 10 minutes, and the density was 974 kg / m ³ .
Further, the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 4.5 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 3.2 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerization vessel 2 / (the mass of the low molecular weight component produced in the polymerization vessel 1 + the mass of the high molecular weight component produced in the polymerization vessel 2)) was 0.47. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 1.05 g / 10 min and a density of 956 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-10) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 1.2%, and the cleanness was too high to measure due to too many particles.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
The rough surface of the parison surface was smooth and the moldability was satisfactory.

[Comparative Example 5]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-11) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 52 mol%. Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 30 g / 10 minutes, and the density was 965 kg / m ³ .
In addition, the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 3.5 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 2.8 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2 The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerization vessel 2 / (the mass of the low molecular weight component produced in the polymerization vessel 1 + the mass of the high molecular weight component produced in the polymerization vessel 2)) is 0.50. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.45 g / 10 min and a density of 951 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-11) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1000 or less by GPC measurement was 0.6%, and many particles were measured for cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, a large striped pattern was generated on the parison surface. Formability is slightly thinner at the bottom corner.

[Comparative Example 6]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-12) Polymerization of polyethylene resin composition Polymerizer as in Example 1 except that the gas phase molar concentration (hydrogen / (ethylene + hydrogen)) of hydrogen with respect to the sum of ethylene and hydrogen is 40 mol% Polymerization was carried out in 1. The melt flow rate (code D) of the low molecular weight portion produced in the polymerization vessel 1 was 5 g / 10 minutes, and the density was 963 kg / m ³ .
The gas phase molar concentration of hydrogen (hydrogen / (ethylene + hydrogen)) with respect to the sum of ethylene and hydrogen is 4.6 mol%, and the gas phase molar concentration of 1-butene with respect to the sum of ethylene and 1-butene (1 -Butene / (ethylene + 1-butene)) was 3.2 mol%, produced in the polymerizer 2 with respect to the sum of the mass of the low molecular weight component produced in the polymerizer 1 and the mass of the high molecular weight component produced in the polymerizer 2. The mass ratio of the high molecular weight component (the mass of the high molecular weight component produced in the polymerization vessel 2 / (the mass of the low molecular weight component produced in the polymerization vessel 1 + the mass of the high molecular weight component produced in the polymerization vessel 2)) is 0.50. Except for polymerizing the high molecular weight component, polymerization was performed in the polymerization vessel 2 in the same manner as in Example 1. This polymerization resulted in a melt flow rate (code T) of 0.62 g / 10 min and a density of 950 kg / min. m ³ polyethylene resin composition The thing was manufactured.
(3-12) Production of polyethylene resin composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1,000 or less by GPC measurement was 0.3%, and a large number of particles were measured for cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, a large striped pattern was generated on the parison surface. There was no problem with moldability.

[Comparative Example 7]
Polyethylene was produced using the catalyst prepared in Example 1.
(2-13) Polymerization of polyethylene resin composition The gas phase molar concentration of hydrogen with respect to the sum of ethylene and hydrogen (hydrogen / (ethylene + hydrogen)) is 26 mol%, and 1-butene with respect to the sum of ethylene and 1-butene. The polymerization was carried out only in the polymerization vessel 1 at a gas phase molar concentration (1-butene / (ethylene + 1-butene)) of 2.0 mol%. In the table, “Single” is indicated, and the polyethylene resin obtained in the polymerization vessel 1 is indicated in the column of the polyethylene resin composition.
By this polymerization, a polyethylene resin composition having a melt flow rate (code T) of 0.69 g / 10 min and a density of 950 kg / m ³ was produced.
(3-13) Production of Polyethylene Resin Composition A polyethylene resin composition was obtained in the same manner as in Example 1 using the resin composition produced as described above.
The ratio of the molecular weight of 1,000 or less by GPC measurement was 0.3%, and a large number of particles were measured for cleanliness.
When the additive extraction analysis was performed on the extruded composition, no additive was detected.
As for rough skin, a large striped pattern was generated on the parison surface, and at the same time, the drawdown was severe and it was difficult to mold a large molded product.

  The composition of the present invention is suitable for containers that are used for applications requiring cleanliness, such as large-sized high-purity chemical containers.

Claims (2)

The polyethylene resin component contained in the polyethylene resin composition is a polyethylene resin composition manufactured using a Ziegler catalyst by a multistage polymerization method comprising at least a low molecular weight component and a high molecular weight component, wherein the low molecular weight component is a melt flow rate (JIS K7210-1999, code D) is 3 g / 10 min or more 50 g / 10 minutes or less, the density (JIS K7112-1999) is ethylene or less 960 kg / ^{m 3} or more 974kg / ^{m 3} homopolymer or ethylene And an α-olefin having 3 to 20 carbon atoms, wherein the mass fraction of the high molecular weight component to the polyethylene resin composition is 0.40 or more and 0.46 or less, and the polyethylene resin composition things, density (JIS K7112-1999) is 955 kg / ^{m 3} or more 965 kg / m Hereinafter, a melt flow rate (JIS K7210-1999, code T) is not more than 0.40 g / 10 min or more 1.0 g / 10 min, large high purity chemicals container, wherein substantially free of additives Polyethylene resin composition.   A large-sized high-purity chemical container formed by molding the polyethylene resin composition according to claim 1.