JP6836372B2 - Polyethylene resin composition, pipes and fittings - Google Patents

Description

The present invention relates to polyethylene resin compositions, pipes and fittings.

Polyethylene resin is excellent in creep characteristics, environmental stress crack resistance, impact characteristics, and flexibility, and has been widely used as a piping material in the past. In recent years, it has been demonstrated that polyethylene pipes are superior to pipe types such as steel pipes and ductile cast iron pipes in that they have characteristics such as the pipes extending following ground fluctuations even in the event of an earthquake. It is attracting attention as a piping material for water and sewage pipes, gas pipes, water supply pipes, etc.

When polyethylene pipe resin is used as a water distribution pipe for a long period of time, stress is applied due to water pressure from the inside of the pipe and soil pressure from the outside at the time of burying, so stress concentration occurs in the minute structural defect part in the pipe and brittleness occurs. Destruction may occur. Improvements have been made to provide a material that has good surface properties and does not cause brittle fracture cracking under such severe conditions where stress is applied over a long period of time.

When an internal pressure is applied to a pipe at a constant temperature, ductile fracture occurs in which swelling occurs and fracture occurs after a certain period of time. There is a stress-rupture time creep relationship between the fracture time of ductile rupture and the stress due to internal pressure, that the lower the stress, the longer the rupture time. It is known that the higher the test temperature, the lower the stress and the shorter the time, and the higher the density of the polyethylene resin, the higher the stress and the longer the time. In addition, chemical resistance is also important because brittle fracture accelerates due to contact with chemicals such as surfactants. As described above, a material that simultaneously satisfies long-term mechanical properties, brittleness fracture resistance, molding processability, surface property, and chemical resistance is desired.

On the other hand, conventionally, in order to maintain rigidity, have excellent long-term characteristics, elongation characteristics and impact resistance, and improve molding processability, the molecular weight distribution is limited to a specific molecular weight range and the molecular weight distribution is wide by two-stage polymerization. Chemical conversion and copolymerization comonomer are introduced as side chains at the time of polymerization. (See, for example, Patent Documents 1 to 6).

Japanese Unexamined Patent Publication No. 2000-109521 Japanese Unexamined Patent Publication No. 2008-101074 Japanese Unexamined Patent Publication No. 2014-43518 Japanese Unexamined Patent Publication No. 2014-227502 Japanese Unexamined Patent Publication No. 2014-129875 Japanese Unexamined Patent Publication No. 2014-133880

However, in Patent Documents 1 to 6, each ethylene polymer of the low molecular weight component and the high molecular weight component is uniformly mixed in the production process, and the molecular weight, melt flow rate, density, α-olefin content, and mixing are performed. By adjusting the ratio, etc., it is adjusted to the physical properties considered to be suitable as a material for pipes and joints. The strength of pipes and joints molded using a mixture of low molecular weight components and high molecular weight components does not maximize the resin strength originally possessed by each ethylene polymer, and is compatible with chemical resistance. Not enough.

The present invention has been made in view of the above problems, and in the ethylene polymer originally used as a raw material for pipes and a mixture thereof, the surface property and surface scratch property when made into a pipe or a joint, An object of the present invention is to provide a polyethylene resin composition, a pipe and a joint having excellent resistance to external stress and chemical resistance.

As a result of diligent studies to solve the above problems, the present invention is used for pipes and joints containing a polyethylene resin composition satisfying a specific constitutional condition or such a polyethylene resin composition, and the surface properties and surface scratches of the pipe and joint. We have found that it is excellent in adhesion, resistance to external stress, and chemical resistance, and have completed the present invention.

That is, the present invention is as follows.
[1]
A polyethylene resin composition containing 75 to 98 parts by mass of the following ethylene-based polymer A and 25 to 2 parts by mass of B.
(Ethylene polymer A)
An ethylene-based polymer containing an ethylene homopolymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms and satisfying the following (1) to (2);
(1) The melt flow rate (code D) (hereinafter referred to as "MFR2.16") is 0.04 g / 10 minutes or more and less than 0.15 g / 10 minutes.
(2) The molecular weight distribution is 15 or more and less than 40.
(Ethylene polymer B)
Ethylene, which contains an ethylene polymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and the ratio of MFR 2.16 to MFR 2.16 of ethylene polymer A is 300 or more and less than 600. System polymer.
[2]
A piping material containing the polyethylene resin composition according to [1].
[3]
The piping material according to [2], wherein the knee point in the FNTFT is 100,000 times or more.
[4]
The piping material according to [2] or [3], wherein the number of breaks at a stress of 10 MPa is 100,000 times or more in the FNTFT.
[5]
The piping material according to any one of [2] to [4], which is one or more selected from the group consisting of pipes and joints.

According to the present invention, it is possible to provide a polyethylene resin composition, a pipe and a joint having excellent surface properties, surface scratch resistance, resistance to external stress, and chemical resistance.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in more detail, but the present invention is not limited to this, and various aspects are not deviated from the gist thereof. It can be transformed.

[Polyethylene resin composition]
The polyethylene resin composition of the present embodiment is
A polyethylene resin composition containing 75 to 98 parts by mass of the following ethylene-based polymer A and 25 to 2 parts by mass of B.
(Ethylene polymer A)
An ethylene-based polymer containing an ethylene homopolymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms and satisfying the following (1) to (2);
(1) MFR2.16 is 0.04 g / 10 minutes or more and less than 0.15 g / 10 minutes.
(2) The molecular weight distribution is 15 or more and less than 40.
(Ethylene polymer B)
Ethylene, which contains an ethylene polymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and the ratio of MFR 2.16 to MFR 2.16 of ethylene polymer A is 300 or more and less than 600. System polymer.

[Ethylene polymer A]
The ethylene-based polymer A in the present embodiment is preferably one that can be used alone as a material for pipes and joints.

The ethylene-based polymer in the present embodiment contains an ethylene homopolymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.
The α-olefin having 3 to 20 carbon atoms in the present embodiment is not particularly limited, but specifically, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 3-methyl-1- Penten, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-icosene, cyclopentene, cyclohexene, cycloheptene, norbornene, Dicyclopentadiene, 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, 1,7-octadiene, cyclohexadiene and the like.

The MFR 2.16 of the ethylene polymer A in the present embodiment is 0.04 g / 10 minutes or more and less than 0.15 g / 10 minutes, preferably 0, from the viewpoint of mechanical properties, molding processability, impact resistance and the like. It is .04 g / 10 minutes or more and less than 0.12 g / 10 minutes, and more preferably 0.04 g / 10 minutes or more and less than 0.10 g / 10 minutes.
The MFR 2.16 of the ethylene-based polymer A can be controlled by the temperature at the time of polymerization, the amount of hydrogen added, and the like. Further, the MFR 2.16 can be measured by the method described in Examples.

[Molecular weight distribution]
The molecular weight distribution of the ethylene-based polymer A in the present embodiment is the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) determined by gel permeation chromatography, and has a molding processability and From the viewpoint of appearance, impact resistance, etc., it is 15 or more and less than 40, preferably 20 or more and less than 40, and more preferably 25 or more and less than 36.
The molecular weight distribution of the ethylene-based polymer A can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of hydrogen added, and the like. In addition, the molecular weight distribution can be measured by the method described in Examples.

The density of the ethylene polymer A in the present embodiment (JIS K7112-1999) is preferably 940~970kg / m ^3, more preferably from ^{945~960kg / m 3, 945~955kg / m} 3 Is more preferable. When the density is 940 kg / m ³ or more, the rigidity of the molded tube tends to be sufficient. Further, when the weight is 970 kg / m ³ or less, the ESCR and elongation characteristics under high temperature acceleration conditions are not deteriorated, and brittle fracture such as crack generation and low speed crack fracture due to long-term use is further suppressed. Tend to be.
The density of the ethylene-based polymer A can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of α-olefin added, and the like. In addition, the density can be measured by the method described in Examples.

The weight average molecular weight of the ethylene-based polymer A in the present embodiment is preferably 200,000 to 500,000, more preferably 200,000 to 450,000, and 250,000 to 400,000. It is more preferable to have. When the weight average molecular weight is 200,000 or more, the molding processability is good, the long-term characteristics of the FNTFT are good, and the impact resistance tends to be excellent. Further, when the weight average molecular weight is 500,000 or less, the mechanical properties tend to be sufficient and the molding processability tends to be good.
The weight average molecular weight of the ethylene-based polymer A can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of hydrogen added, and the like. In addition, the weight average molecular weight can be measured by the method described in Examples.

The ethylene-based polymer A is preferably obtained by two-stage polymerization. It is preferably prepared by two-step polymerization, and (1) MFR2.16 is 0.04 g / 10 minutes or more and less than 0.15 g / 10 minutes, and (2) the molecular weight distribution is 15 or more and less than 40. The MFR 2.16 of the ethylene-based polymer A can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of hydrogen to be added, and the like. Further, the molecular weight distribution of the ethylene-based polymer A can be controlled by the catalyst used at the time of production, the polymerization temperature, the residence time of the polymerization tank, and the like.
Specifically, the two-stage polymerization is carried out by two polymerization tanks, and only ethylene is supplied as a monomer to the first-stage polymerization tank, and ethylene and an α-olefin having 3 to 20 carbon atoms are supplied to the second stage. It is preferable to supply and polymerize.
Further, the production amount of the polyethylene resin component composed of the ethylene homopolymer obtained in the first-stage polymerization tank is set to 30 to 60 wt%, and the production of the polyethylene resin component composed of the copolymer obtained in the second-stage polymerization tank is set to 30 to 60 wt%. The ratio of the amount is preferably 70 to 40 wt%.
The ratio of the production amount of the polyethylene resin component composed of the ethylene homopolymer obtained in the first-stage polymerization tank is 40 to 60 wt%, and the production amount of the polyethylene resin component composed of the copolymer obtained in the second-stage polymerization tank is set to 40 to 60 wt%. More preferably, the ratio is 60 to 40 wt%.
The ratio of the production amount of the polyethylene resin component composed of the ethylene homopolymer obtained in the first-stage polymerization tank is set to 50 to 60 wt%, and the production amount of the polyethylene resin component composed of the copolymer obtained in the second-stage polymerization tank is set to 50 to 60 wt%. It is more preferable that the ratio is 50 to 40 wt%.

[Ethylene polymer B]
As described above, it is preferable that the ethylene-based polymer A can be used alone as a material for pipes and joints, and the polyethylene resin composition of the present embodiment has a longer life for pipes and joints. It contains an ethylene polymer B to be used as a material for joints.
The ethylene-based polymer B contains an ethylene-based polymer and / or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and the ethylene-based polymer and ethylene in the ethylene-based polymer B. The definition of a copolymer of 3 to 20 carbon atoms and an α-olefin having 3 to 20 carbon atoms is the same as the definition of an ethylene polymer in ethylene-based polymer A and a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Is.

The ethylene-based polymer B can be obtained by polymerization in only one stage or by two-stage polymerization.
When the polymerization is carried out in only one stage, specifically, it is preferable to supply ethylene and an α-olefin having 3 to 20 carbon atoms to the polymerization tank for polymerization. The MFR 2.16 of the ethylene polymer B can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of hydrogen added, and the like.

In the polyethylene resin composition of the present embodiment, the ratio of the MFR 2.16 of the ethylene polymer A to the MFR 2.16 of the ethylene polymer B is important. The ratio of MFR 2.16 of ethylene polymer B to MFR 2.16 of ethylene polymer A (MFR 2.16 of ethylene polymer B / MFR 2.16 of ethylene polymer A) is 300 or more and less than 600. Yes, preferably 400 or more and less than 550, and more preferably 450 or more and less than 550. When the ratio of MFR 2.16 is in the above range, the strength of the molded product is improved. The reason why the strength of the molded product is improved when the ratio of MFR 2.16 is in the above range is not certain, but in the process of kneading the ethylene-based polymers A and B in the molding machine, the ethylene-based polymers A and B Is presumed to be mutually stretched and oriented. Even if the ethylene-based polymers A and B are compatible or separated, the strength of the molded product does not tend to improve, and the surface surface of the molded product is rough, especially under the condition that the ethylene-based polymers A and B are separated. Is easy to cause. The ratio of the MFR 2.16 of the ethylene polymer A to the MFR 2.16 of the ethylene polymer B is determined by the MFR 2.16 of the ethylene polymer A and the MFR 2.16 of the ethylene polymer B to be selected.

The MFR 2.16 of the ethylene polymer B in the present embodiment is not particularly limited as long as it satisfies the above MFR 2.16 ratio, and is preferably 10 to 100 g / 10 minutes, and is preferably 20 to 50 g / 10 minutes. Is more preferable, and 24 to 45 g / 10 minutes is even more preferable.
The MFR 2.16 of the ethylene-based polymer B can be controlled by the temperature at the time of polymerization, the amount of hydrogen added, and the like. Further, the MFR 2.16 can be measured by the method described in Examples.

The density of the ethylene-based polymer B according to the present embodiment is preferably 950~970kg / m ^3, more preferably from 955~965kg / m ^3, more preferably a 955~963kg / m ³ .. When the density is 950 kg / m ³ or more, sudden brittle fracture on the long-term side in the hot internal pressure creep characteristic is less likely to occur, and the long-term characteristic tends to be sufficient.
The density of the ethylene-based polymer B can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of α-olefin added, and the like. In addition, the density can be measured by the method described in Examples.

The weight average molecular weight of the ethylene-based polymer B in the present embodiment is preferably 20,000 to 100,000, more preferably 30,000 to 50,000, and 35,000 to 45,000. It is more preferable to have. When the weight average molecular weight of the ethylene-based polymer B is 20,000 or more, there is no stickiness or deterioration of long-term characteristics, and the dispersibility with the ethylene-based polymer A tends to be excellent. Further, when the weight average molecular weight of the ethylene polymer B is 100,000 or less, the moldability tends to be good.
The weight average molecular weight of the ethylene-based polymer B can be controlled by the catalyst used at the time of production, the polymerization temperature, the amount of hydrogen added, and the like. In addition, the weight average molecular weight can be measured by the method described in Examples.

[Mixing ratio of ethylene polymer]
The polyethylene resin composition of the present embodiment contains an ethylene-based polymer A and an ethylene-based polymer B, and the ethylene-based polymer A is 75 to 98 parts by mass, preferably 85 to 98 parts by mass. More preferably, it is 90 to 98 parts by mass. The ethylene-based polymer B is 25 to 2 parts by mass, preferably 15 to 2 parts by mass, and more preferably 10 to 2 parts by mass. By setting the proportion of ethylene-based polymer A to 98 parts by mass or less and the proportion of ethylene-based polymer B to 2 parts by mass or more, the surface properties when made into a pipe are superior, and especially when used as a water supply or hot water supply pipe. It is a high-quality product with suppressed surface roughness and unevenness during molding. Further, by setting the proportion of the ethylene-based polymer A to 75 parts by mass or more and the proportion of the ethylene-based polymer B to 25 parts by mass or less, the high molecular weight component becomes sufficient, and the long-term side of the hot internal pressure creep It tends to have sufficient life, elongation characteristics and impact resistance.

(Method for producing ethylene polymer)
The ethylene-based polymers A and B in the present embodiment are subjected to a Vessel-type slurry polymerization method using one or more selected from the group consisting of a Ziegler catalyst, a Phillips-type catalyst, and a supported geometrically constrained single-site catalyst. Can be manufactured. Among these, it is preferable to use a Ziegler catalyst and / or a supported geometrically constrained single-site catalyst.

The Ziegler catalyst is a catalyst for olefin polymerization containing a titanium chloride compound and an alkylaluminum compound as essential components (see, for example, P.836 of the 5th edition of the Physics and Chemistry Dictionary (Iwanami Shoten)). The method for producing the Ziegler catalyst is not particularly limited, but it is preferably produced by the following production method.
The ethylene-based polymers A and B in the present embodiment are preferably produced by a Ziegler catalyst containing a solid catalyst component [A] and an organoaluminum compound [B].

Here, the solid catalyst component [A] is 1 mol of the organic magnesium compound (i) soluble in the hydrocarbon solvent represented by the following formula (1) and the chlorosilane compound (ii) represented by the following formula (2) 0. A solid (A-1a) is obtained by reacting with 01 to 100 mol, and 0.01 to 1 mol of alcohol (A-2) is added to 1 mol of C-Mg bond contained in the solid (A-1a). The reaction is carried out to obtain a solid (A-1b), and the solid (A-1b) is further reacted with an organometallic compound (A-3) represented by the following formula (3) to form a solid (A-1c). A cheegler catalyst for olefin polymerization produced by further carrying an organometallic compound represented by the following formula (5) and a titanium compound (A-4) on the solid (A-1c), if necessary. Is preferable. The titanium compound is not particularly limited, but specifically, the titanium compound (A-4) represented by the following formula (4) is preferable.

(Al) _a (Mg) _b (R ¹ ) _c (R ² ) _d (OR ³ ) _e ... (1)

(In the formula (1), R ¹ , R ² and R ³ are hydrocarbon groups having 2 to 20 carbon atoms, and a, b, c, d and e are numbers satisfying the following relationship: 0 ≦ a. , 0 <b, 0 ≦ c, 0 ≦ d, 0 ≦ e, 0 <c + d, 0 ≦ e / (a + b) ≦ 2, 3a + 2b = c + d + e)

H _h SiCl _i R ⁴ _{(4- (h + i))}・ ・ ・ ・ ・ (2)

(In the formula (2), R ⁴ is a hydrocarbon group having 1 to 20 carbon atoms, and h and i are numbers satisfying the following relationship. 0 <h, 0 <i, h + i ≦ 4)

AlR ⁵ _s Q _3-s ... (3)

In formula (3), R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and Q is selected from the group consisting ^{of OR 6} , OSiR ⁷ R ⁸ R ⁹ , NR ¹⁰ R ¹¹ , SR ^{12 and halogen.} Representing a group, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are hydrogen atoms or hydrocarbon groups, and s is a number that satisfies the following relationship. 0 <s <3. )

Ti (OR ⁵ ) _j X _(4-j)・ ・ ・ ・ ・ (4)

(In formula (4), j is a real number from 0 to 4, R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and X is a halogen atom.)

First, the organic magnesium compound (i) will be described. The organic magnesium compound (i) is shown in the form of a complex of organic magnesium soluble in an inert hydrocarbon solvent, but includes all of the dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds. It is something to do. The symbols a, b, c, d and e of the formula (1) satisfy the relational expression 3a + 2b = c + d + e, which indicates the stoichiometry of the valence of the metal atom and the substituent.

In the above formula (1), ^{the hydrocarbon group having 2 to 20 carbon atoms represented by R 1} and R ² is not particularly limited, and specific examples thereof include an alkyl group, a cycloalkyl group and an aryl group, respectively. Examples thereof include methyl, ethyl, propyl, butyl, propyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Of these, R ¹ and R ² are preferably alkyl groups, respectively.

The ratio b / a of magnesium to aluminum is not particularly limited, but is preferably 0.1 to 30, more preferably 0.5 to 10. Further, when a = 0, for example, R ¹ is preferably 1-methylpropyl or the like, whereby the organic magnesium compound (i) tends to be more soluble in an inert hydrocarbon solvent. Further, in the equation (1), when a = 0, R ¹ and R ² satisfy any one of the following three groups (1), (2), and (3). preferable.

Group (1) it is preferable that at least one of R ^1, R ² is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, R ^1, R ² are both 4-6 carbon atoms, at least More preferably, one is a secondary or tertiary alkyl group.
Group (2) R ¹ and R ² are preferably alkyl groups having different ^{carbon atoms, 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. More preferably.
Preferably the group (3) at least one of R ^1, R ² is a hydrocarbon group having 6 or more carbon atoms, that the sum of the number of carbon atoms contained in R ^1, R ² is an alkyl group of 12 or more More preferred.

Hereinafter, these groups will be specifically shown. Specific examples of the secondary or tertiary alkyl group having 4 to 6 carbon atoms in the group (1) include 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2-methylbutyl, and 2 -Ethylpropyl, 2,2-dimethylpropyl, 2-methylpentyl, 2-ethylbutyl, 2,2-dimethylbutyl, 2-methyl-2-ethylpropyl group and the like can be mentioned. Of these, a 1-methylpropyl group is preferable.
Next, examples of the alkyl group having 2 or 3 carbon atoms in the group (2) include ethyl, 1-methylethyl, propyl group and the like, and an ethyl group is preferable. The alkyl group having 4 or more carbon atoms is not particularly limited, and specific examples thereof include butyl, pentyl, hexyl, heptyl, and octyl groups. Of these, butyl and hexyl groups are preferable.

The hydrocarbon group having 6 or more carbon atoms in the group (3) is not particularly limited, and specific examples thereof include hexyl, heptyl, octyl, nonyl, decyl, phenyl, and 2-naphthyl group. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, a hexyl group and an octyl group are particularly preferable.

Generally, as the number of carbon atoms contained in the alkyl group increases, it tends to be more soluble in the inert hydrocarbon solvent, but in order to increase the viscosity of the solution, it is preferable to use an alkyl group having a chain length as needed. The organic magnesium compound (i) is used in the state of an inert hydrocarbon solution, but even if the solution contains or remains a trace amount of Lewis basic compounds such as ether, ester, and amine. It can be used without any problem. The inert hydrocarbon solvent is not particularly limited, but specifically, aliphatic hydrocarbons such as pentane, hexane and heptane; aromatic hydrocarbons such as benzene and toluene; and cyclohexane, methylcyclohexane and the like. Aliphatic hydrocarbons and the like can be mentioned.

Next, the alkoxy group (OR ³ ) will be described. The hydrocarbon group represented by R ³ having 2 to 20 carbon atoms is not particularly limited, but specifically, an alkyl group having 2 to 20 carbon atoms or an aryl group is preferable, and an alkyl group having 3 to 10 carbon atoms is preferable. Alternatively, an aryl group is more preferable. The alkyl group or aryl group having 2 to 20 carbon atoms is not particularly limited, but specifically, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 1,1-dimethylethyl, pentyl. , Hexil, 2-methylpentyl, 2-ethylbutyl, 2-ethylpentyl, 2-ethylhexyl, 2-ethyl-4-methylpentyl, 2-propylheptyl, 2-ethyl-5-methyloctyl, octyl, nonyl, decyl, Examples include phenyl and naphthyl groups. Of these, butyl, 1-methylpropyl, 2-methylpentyl and 2-ethylhexyl groups are more preferred.

The method for synthesizing the organic magnesium compound (i) is not particularly limited, but is ^{a group consisting of the formulas R 1} MgX and R ¹ ₂ Mg (R ¹ is a group similar to the above, and X is a halogen atom). An organic magnesium compound selected from the ^{above and an organic metal compound selected from the group consisting of the formulas AlR 2} ₃ and Al ^{R 2} ₂ H (R ² is the same group as described above) are mixed in an inert hydrocarbon solvent at 25 ° C. It can be obtained by reacting at a temperature of ~ 150 ° C. If necessary, following this reaction, ^{an alcohol having a hydrocarbon group represented by R 3} (R ³ is a group similar to the above), R ^{3 soluble in an inert hydrocarbon solvent.} A method of reacting with an alkoxymagnesium compound having a hydrocarbon group represented by and / or an alkoxyaluminum compound is preferable.

Of these, when the organic magnesium compound soluble in the inert hydrocarbon solvent is reacted with the alcohol, the order of the reactions is not particularly limited, and the method of adding the alcohol to the organic magnesium compound and the organic magnesium in the alcohol Either a method of adding the compound or a method of adding both at the same time can be used. The reaction ratio of the organic magnesium compound soluble in the inert hydrocarbon solvent to the alcohol is not particularly limited, but the molar composition ratio of the alkoxy group to all metal atoms in the alkoxy group-containing organic magnesium compound obtained as a result of the reaction e. / (A + b) is 0 ≦ e / (a + b) ≦ 2, and 0 ≦ e / (a + b) <1 is preferable.

Next, the chlorosilane compound (ii) will be described. The chlorosilane compound (ii) is a silicon chloride compound represented by the formula (2) and having at least one Si—H bond.
H _h SiCl _i R ⁴ _{(4- (h + i))}・ ・ ・ ・ ・ Equation (2)
(In the formula (2), R ⁴ is a hydrocarbon group having 1 to 20 carbon atoms, and h and i are numbers satisfying the following relationship. 0 <h, 0 <i, h + i ≦ 4)

^{The hydrocarbon group having 1 to 20 carbon atoms represented by R 4} in the formula (2) is not particularly limited, but specifically, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon. Examples include hydrogen groups such as methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl, hexyl, octyl, decyl, cyclohexyl and phenyl groups. Among these, an alkyl group having 1 to 10 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl, propyl and 1-methylethyl groups is more preferable. Further, h and i are numbers larger than 0 that satisfy the relationship of h + i ≦ 4, and i is preferably 2 to 3.

Such chlorosilane compound (ii) is not particularly limited, but specifically, 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, etc. Be done. Among these, HSiCl ₃ , HSiCl ₂ CH ₃ , HSiCl (CH ₃ ) ₂ , and HSiCl ₂ C ₂ H ₅ are preferable, and HSiCl ₃ and HSiCl ₂ CH ₃ are more preferable. The chlorosilane compound may be used alone or in combination of two or more.

Next, the reaction between the organic magnesium compound (i) and the chlorosilane compound (ii) will be described. In the reaction, the chlorosilane compound (ii) is previously added to an inert hydrocarbon solvent; chlorinated hydrocarbons such as 1,2-dichloroethane, o-dichlorobenzene and dichloromethane; ether-based media such as diethyl ether and tetrahydrofuran; or a mixed medium thereof. It is preferable to use it after diluting it with, and an inert hydrocarbon solvent is more preferable in terms of the performance of the catalyst. The reaction ratio between the organic magnesium compound (i) and the chlorosilane compound (ii) is not particularly limited, but the silicon atom contained in the chlorosilane compound (ii) is 0.01 mol or more with respect to 1 mol of the magnesium atom contained in the organic magnesium compound (i). It is preferably 100 mol or less, and more preferably 0.1 mol to 10 mol.

The reaction method between the organic magnesium compound (i) and the chlorosilane compound (ii) is not particularly limited, and a method of simultaneous addition in which the organic magnesium compound (i) and the chlorosilane compound (ii) are simultaneously introduced into the reactor and reacted. , A method of introducing the organic magnesium compound (i) into the reactor after charging the chlorosilane compound (ii) in the reactor in advance, and the chlorosilane compound (ii) after charging the organic magnesium compound (i) into the reactor in advance. Any method may be used, but a method in which the chlorosilane compound (ii) is charged in the reactor in advance and then the organic magnesium compound (i) is introduced into the reactor is preferable. The solid (A-1a) obtained by the above reaction is preferably separated by filtration or decantation method, and then thoroughly washed with an inert hydrocarbon solvent to remove unreacted products or by-products. ..

The reaction temperature of the organic magnesium compound (i) and the chlorosilane compound (ii) is not particularly limited, but is preferably 25 ° C to 150 ° C, more preferably 40 ° C to 150 ° C, and 50 ° C to 50 ° C. It is more preferably 150 ° C. In the method of simultaneous addition in which the organic magnesium compound (i) and the chlorosilane compound (ii) are simultaneously introduced into the reactor and reacted, the temperature of the reactor is adjusted to a predetermined temperature in advance, and the inside of the reactor is added while the simultaneous addition is performed. The reaction temperature is preferably adjusted to a predetermined temperature by adjusting the temperature of the above to a predetermined temperature. In the method in which the chlorosilane compound (ii) is charged into the reactor in advance and then the organic magnesium compound (i) is introduced into the reactor, the temperature of the reactor charged with the chlorosilane compound (ii) is adjusted to a predetermined temperature, and the organic magnesium compound (i) is introduced into the reactor. It is preferable to adjust the reaction temperature to a predetermined temperature by adjusting the temperature inside the reactor to a predetermined temperature while introducing the magnesium compound (i) into the reactor. In the method of introducing the chlorosilane compound (ii) into the reactor after charging the organic magnesium compound (i) into the reactor in advance, the temperature of the reactor charged with the organic magnesium compound (i) is adjusted to a predetermined temperature. The reaction temperature can be adjusted to a predetermined temperature by adjusting the temperature inside the reactor to a predetermined temperature while introducing the chlorosilane compound (ii) into the reactor.

The reaction between the organic magnesium compound (i) and the chlorosilane compound (ii) can also be carried out 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. Examples of the inorganic solid include the following.
(I) Inorganic oxide (II) Inorganic carbonate, silicate, sulfate (III) Inorganic hydroxide (IV) Inorganic halide (V) A double salt, solid solution, or mixture consisting of (I) to (IV).

Specific examples of the inorganic solid are not particularly limited, but specifically, silica, alumina, silica / alumina, hydrated alumina, magnesia, tria, titania, zirconia, calcium phosphate / barium sulfate, calcium sulfate, magnesium silicate, magnesium silicate. 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 silicate Examples thereof include iron [(Mg · Fe) 2SiO ₄ ], aluminum silicate [Al ₂ O ₃ · SiO ₂ ], calcium carbonate, magnesium chloride, magnesium iodide and the like. Of these, silica, silica-alumina, and magnesium chloride are preferable. The specific surface area of the inorganic solid is preferably 20 m ² / g or more, and more preferably 90 m ² / g or more.

The solid (A-1a) obtained as described above is further reacted with an alcohol (A-2) to obtain a solid (A-1b). The alcohol (A-2) used at this time is not particularly limited, and specific examples thereof include saturated or unsaturated alcohols having 1 to 20 carbon atoms, such as methyl alcohol and ethyl alcohol. Propyl alcohol, iso-propyl alcohol, butyl alcohol, iso-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, iso-amyl alcohol, sec-amyl alcohol, tert-amyl alcohol, hexyl alcohol, cyclo Hexanol, phenol, cresol and the like can be mentioned. Of these, C ₃ to C ₈ linear alcohols, iso-butyl alcohols, and iso-amyl alcohols are preferable.

Next, the amount of the alcohol (A-2) used is preferably 0.01 to 1 mol, more preferably 0.05 to 0.5 mol, per 1 mol of the C-Mg bond contained in the solid (A-1a). It is more preferably in the range of 0.1 to 0.25 mol. The reaction of the solid (A-1a) with the alcohol (A-2) can be carried out in the presence or absence of an inert medium. As the inert medium, any of the above-mentioned aliphatic, aromatic, and alicyclic hydrocarbons may be used. The temperature at the time of reaction is not particularly limited, but it can be preferably carried out at room temperature to 200 ° C.

Next, the solid (A-1b) obtained by the reaction of the solid (A-1a) with the alcohol (A-2) is reacted with the organometallic compound (A-3) represented by the following formula (3). The solid (A-1c) can be obtained.
AlR ⁵ _s Q _3-s・ ・ ・ ・ ・ Expression (3)
In formula (3), R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and Q is selected from the group consisting ^{of OR 6} , OSiR ⁷ R ⁸ R ⁹ , NR ¹⁰ R ¹¹ , SR ^{12 and halogen.} Representing a group, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are hydrogen atoms or hydrocarbon groups, and s is a number that satisfies the following relationship. 0 <s <3. ).

The organic metal compound (A-3) is not particularly limited, but specifically, trimethylaluminum, triethylaluminum, trin-propylaluminum, trin-butylaluminum, triiso-butylaluminum, trin-amyl. Trialkylaluminum such as aluminum, triiso-amylaluminum, trin-hexylaluminum, trin-octylaluminum, trin-decylaluminum; diethylaluminum chloride, ethylaluminum dichloride, diiso-butylaluminum chloride, ethylaluminum sesquichloride , Aluminum halides such as diethylaluminum bromide; alkoxyaluminums such as diethylaluminum ethoxide, diiso-butylaluminum butoxide; siloxyalkylaluminums such as dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminumdiethyl; And a mixture thereof and the like. Of these, aluminum halide is preferable, and dimethylaluminum chloride, methylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride, dipropylaluminum chloride, and dibutylaluminum chloride are more preferable.

For the reaction between the solid (A-1b) obtained by the reaction of the solid (A-1a) and the alcohol (A-2) and the organometallic compound (A-3), an inert reaction medium is preferably used. Can be done. Such an inert reaction medium is not particularly limited, but specifically, an aliphatic hydrocarbon such as hexane or heptane; an aromatic hydrocarbon such as benzene or toluene; an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane. Examples include hydrogen. Of these, aliphatic hydrocarbons are preferable. The amount of the organometallic compound (A-3) used is preferably 0.5 mol or less, more preferably 0.1 mol or less, per 1 mol of the C-Mg bond contained in the solid component (A-1a). The reaction temperature is not particularly limited, but it is preferably carried out in the range of room temperature to 150 ° C.

Next, the titanium compound (A-4) will be described. The titanium compound (A-4) is preferably a titanium compound represented by the above formula (4).

Ti (OR ⁵ ) _j X _(4-j)・ ・ ・ ・ ・ Equation (4)

(In formula (4), j is a real number from 0 to 4, R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and X is a halogen atom.)

The hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵ is not particularly limited, but specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, decyl, and the like. Examples thereof include aliphatic hydrocarbon groups such as allyl groups; alicyclic hydrocarbon groups such as cyclohexyl, 2-methylcyclohexyl and cyclopentyl groups; aromatic hydrocarbon groups such as phenyl and naphthyl groups. Of these, an aliphatic hydrocarbon group is preferable. Examples of the halogen represented by X include chlorine, bromine and iodine, but chlorine is preferable. The titanium compound (A-4) can be used alone or in combination of two or more.

The amount of the titanium compound (A-4) used is not particularly limited, but the molar ratio of the titanium compound (A-1c) to the magnesium atom is preferably 0.01 to 20, more preferably 0.05 to 10. ..

The reaction temperature of the solid (A-1c) and the titanium compound (A-4) is not particularly limited, but is preferably carried out in the range of 25 ° C. to 150 ° C.

The method of supporting the titanium compound (A-4) with respect to the solid (A-1c) is not particularly limited, and the method of reacting the excess titanium compound (A-4) with the solid (A-1c) and the third component You may use the method of efficiently supporting the titanium compound (A-4) by using the above, but the method of supporting by the reaction of the titanium compound (A-4) and the organic metal compound (A-5) is used. preferable.

Next, the organometallic compound (A-5) will be described. As (A-5), those represented by the following formula (5) or formula (6) are preferable.

(M ¹ ) _a (Mg) _b (R ¹ ) _c (R ² ) _d Y _e ... (5)

(In the formula (5), M ¹ is a metal atom other than magnesium selected from the group consisting of the first group, the second group, the twelfth group and the thirteenth group of the periodic table, and R ¹ and R ² are described above. Y is alkoxy, siloxy, allyloxy, amino, amide, -N = C-R ⁶ , R ⁷ , -SR ⁸ , β-keto acid residues (where R ⁶ , R ⁷ and R ^8). Represents a hydrocarbon group having 1 to 20 carbon atoms. When e is 2 or more, Y may be different from each other), and a, b, c, d and e are as follows. It is a real number that satisfies the 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 (here, f is the valence of ^{M 1.))}

M ² R ⁹ _k Q _(mk)・ ・ ・ ・ ・ (6)

(In formula (6), M ² is a metal atom selected from the group consisting of Group 1, Group 2, Group 12, and Group 13 of the periodic table, and R ⁹ is a hydrocarbon having 1 to 20 carbon atoms. Group, Q represents a group selected from the group consisting ^{of OR 10} , OSiR ¹¹ R ¹² R ¹³ , NR ¹⁴ R ¹⁵ , SR ^{16 and halogen, R 10} , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen atoms or hydrocarbon groups, k is a real number greater than 0, and m is the valence of ^{M 2.)}

Hereinafter, the organometallic compounds represented by the above formulas (5) and (6) are referred to as an organometallic compound (A-5a) and an organometallic compound (A-5b), respectively.

First, the organometallic compound (A-5a) will be described. The amount of the organometallic compound (A-5a) used is 0.1 to 10 in terms of the molar ratio of the magnesium atom contained in the organometallic compound (A-5a) to the titanium atom contained in the titanium compound (A-4). It is preferably 0.5 to 5, and more preferably 0.5 to 5. The temperature of the reaction between the titanium compound (A-4) and the organometallic compound (A-5a) is not particularly limited, but is preferably -80 ° C to 150 ° C, and is in the range of -40 ° C to 100 ° C. Is more preferable.
The concentration of the organometallic compound (A-5a) when used is not particularly limited, but may be 0.1 mol / L to 2 mol / L based on the magnesium atom contained in the organometallic compound (A-5a). It is preferably 0.5 mol / L to 1.5 mol / L, and more preferably 0.5 mol / L to 1.5 mol / L. It is preferable to use an inert hydrocarbon solvent for diluting the organometallic compound (A-5a).

The order of addition of the titanium compound (A-4) and the organic metal compound (A-5a) to the solid (A-1c) is not particularly limited, and the titanium compound (A-4) is followed by the organic metal compound (A-5a). ), The organic metal compound (A-5a) followed by the titanium compound (A-4), and the titanium compound (A-4) and the organic metal compound (A-5a) are added at the same time. Although a method is also possible, a method in which the titanium compound (A-4) and the organic metal compound (A-5a) are added at the same time is preferable. The reaction between the titanium compound (A-4) and the organic metal compound (A-5a) is carried out in an inert hydrocarbon solvent, and 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, the organometallic compound (A-5b) will be described. The organometallic compound (A-5b) is an organometallic compound represented by the formula (6). In the above formula (6), M ² is a metal atom selected from the group consisting of Group 1, Group 2, Group 12, and Group 13 of the periodic table, and is not particularly limited, but specifically, lithium. , Sodium, potassium, beryllium, magnesium, boron, aluminum, zinc and the like. Of these, magnesium, boron and aluminum are preferable. The hydrocarbon group having 1 to 20 carbon atoms represented by R ⁹ is not particularly limited, and specific examples thereof include an alkyl group, a cycloalkyl group and an aryl group, and examples thereof include methyl, ethyl, propyl and butyl. , Pentyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Among these, the hydrocarbon group having 1 to 20 carbon atoms represented by R9 is preferably an alkyl group.

Q represents a group selected from the group consisting of OR ¹⁰ , OSiR ¹¹ R ¹² R ¹³ , NR ¹⁴ R ¹⁵ , SR ^{16 and halogen, R 10} , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ^{Reference numeral 16} is a hydrogen atom or a hydrocarbon group, and Q is preferably a halogen.

Such an organic metal compound (A-5b) is not particularly limited, but specifically, methyllithium, butyllithium, methylmagnesium chloride, methylmagnesium bromide, methylmagnesium iodide, ethylmagnesium chloride, ethylmagnesium bromide. , Ethyl Magnesium Iodide, Butyl Magnesium Chloride, Butyl Magnesium Bromide, Butyl Magnesium Iodide, Dibutyl Magnesium, Dihexyl Magnesium, Triethyl Boron, trimethyl Aluminum, Dimethyl Aluminum Bromide, Dimethyl Aluminum Chloride, Dimethyl Aluminum Cymode, Methyl Aluminum Dichloride, Methyl Aluminum Sesquichloride, triethylaluminum, diethylaluminum chloride, diethylaluminum bromide, diethylaluminum ethoxide, ethylaluminum dichloride, ethylaluminum sesquichloride, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum, trihexylaluminum, trioctyl Examples thereof include aluminum and tridecyl aluminum. Of these, organoaluminum compounds are preferable. Further, these compounds may be used alone or in combination of two or more. k is a real number greater than 0, preferably a real number greater than 0.5.

The amount of the organometallic compound (A-5b) used is 0.1 to 10 in ^{terms of the molar ratio of M 2} atoms contained in the organometallic compound (A-5b) to the titanium atoms contained in the titanium compound (A-4). It is preferably present, and more preferably 0.5 to 5. The temperature of the reaction between the titanium compound (A-4) and the organometallic compound (A-5b) is not particularly limited, but is preferably 20 ° C to 150 ° C, more preferably 40 ° C to 100 ° C. ..

The concentration of the organometallic compound (A-5b) when used is not particularly limited, but it should be ^{0.1 mol / L to 2} mol / L based on the M 2 atom contained in the organometallic compound (A-5b). Is preferable, and 0.5 mol / L to 1.5 mol / L is more preferable. It is preferable to use an inert hydrocarbon solvent for diluting the organometallic compound (A-5b).

The method of adding the titanium compound (A-4) and the organic metal compound (A-5b) to the solid (A-1c) is not particularly limited. First, the titanium compound (A-4) is added, and then the organic compound (A-4) is added. A method of adding a metal compound (A-5b), a method of first adding an organic metal compound (A-5b), and then a method of adding a titanium compound (A-4), a method of adding a titanium compound (A-4) and an organic compound. Either method of adding the metal compound (A-5b) at the same time is possible, but first the organic metal compound (A-5b) is added, and then the titanium compound (A-4) is added. The method of doing is preferable. The reaction between the titanium compound (A-4) and the organic metal compound (A-5b) is carried out in an inert hydrocarbon solvent, and 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 the organometallic compound (A-5b) is used, before adding the titanium compound (A-4) and the organometallic compound (A-5b) to the solid (A-1c), the solid (A-5b) is used. It is preferable that A-1c) is reacted with an alcohol in advance and further reacted with an organometallic compound (A-5b).

Such alcohol is not particularly limited, but specifically, one having 1 to 10 carbon atoms is preferable, and for example, methanol, ethanol, propanol, 2-propanol, 1-butanol, 2-butanol, 2- Examples thereof include methyl-1-propanol, 1-methyl-2-propanol, 1-pentanol, 1-hexanol, 1-octanol, 2-ethyl-1-hexanol, decanol and the like. Among these, those having 2 to 6 carbon atoms are more preferable, and for example, ethanol, propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-methyl-2-propanol, etc. Examples thereof include 1-pentanol and 1-hexanol. The amount of alcohol used is not particularly limited, but the molar ratio to the magnesium atom contained in the solid (A-1c) is preferably 0.01 to 1, and more preferably 0.01 to 0.5. .. The concentration of alcohol at the time of use is not particularly limited, but it is preferable to dilute it to 0.1 M to 2 M with an inert hydrocarbon solvent before use. The temperature of the reaction between the solid (A-1c) and the alcohol is not particularly limited, but is preferably 25 ° C to 150 ° C, more preferably 40 ° C to 80 ° C.

The reaction between the solid (A-1c) and the organometallic compound (A-5b) after the reaction with the alcohol will be described. The amount of the organometallic compound (A-5b) used is not particularly limited, but the molar ratio to the alcohol used is preferably 0.1 to 10, more preferably 0.5 to 5 times. The concentration of the organometallic compound (A-5b) when used is not particularly limited, but is preferably 0.1 mol / L to 2 mol / L based on the M2 atom contained in the organometallic compound (A-5b). , 0.5 mol / L to 1.5 mol / L, more preferably. It is preferable to use an inert hydrocarbon solvent for diluting the organometallic compound (A-5b). The temperature of the reaction between the solid (A-1c) and the organometallic compound (A-5b) after the reaction with the alcohol is not particularly limited, but is preferably 25 ° C. to 150 ° C. or lower, preferably 40 ° C. to 80 ° C. More preferably, it is ° C.

Next, the organometallic compound component [B] will be described. The solid catalyst component [A] becomes a highly active polymerization catalyst when combined with the organometallic compound component [B]. The organometallic compound component [B] is not particularly limited, but specifically, it is a compound containing a metal selected from the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table. It is preferably present, and more preferably an organic aluminum compound and / or an organic magnesium compound.

As such an organoaluminum compound, it is preferable to use the compound represented by the following formula (7) alone or in combination.

AlR ¹⁷ _n Z _(3-n)・ ・ ・ ・ ・ (7)

(In the formula, R ¹⁷ is a group selected from the group consisting of hydrocarbon groups having 1 to 20 carbon atoms, Z is a group consisting of hydrogen, halogen, alkoxy, allyloxy, and siloxy groups, and n is a number of 2 to 3.)

In the above formula (7), ^{the hydrocarbon group having 1 to 20 carbon atoms represented by R 17} is not particularly limited, but specifically, an aliphatic hydrocarbon, an aromatic hydrocarbon, or an alicyclic hydrocarbon. Examples include those containing hydrogen. The compound represented by the formula (7) is not particularly limited, and is, for example, trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum, tripentylaluminum, and tri (tri). 3-Methylbutyl) aluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum and other trialkylaluminum; diethylaluminum chloride, ethylaluminum dichloride, bis (2-methylpropyl) aluminum chloride, ethylaluminum sesquichloride, diethylaluminum bromide and the like. Aluminum halide compounds; alkoxyaluminum compounds such as diethylaluminum ethoxide and bis (2-methylpropyl) aluminum butoxide; syroxyaluminum compounds such as dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl and ethyldimethylsiloxyaluminum diethyl; And mixtures thereof are preferred. Of these, trialkylaluminum compounds are more preferred.

As the organic magnesium compound, an organic magnesium compound that is soluble in an inert hydrocarbon solvent represented by the formula (8) is preferable.

(M ¹ ) _a (Mg) _b (R ¹ ) _c (R ² ) _d (OR ³ ) _e ... Equation (8)

(In the formula, M ¹ is a metal atom other than magnesium selected from the group consisting of Group 1, Group 2, Group 12 and Group 13 of the periodic table, and R ¹ and R ² have 2 to 2 carbon atoms, respectively. There are 20 hydrocarbon groups, 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 atomic value of ^{M 1))}

Further, such an organic magnesium compound is shown as a complex compound of organic magnesium soluble in an inert hydrocarbon solvent, but all of the dialkylmagnesium compound and the complex of this compound and another metal compound. It includes. Since this organic magnesium compound is preferably a compound having high solubility in an inert hydrocarbon solvent, b / a is preferably 0.5 to 10 and more preferably a compound in which ^{M 1 is aluminum.}

The method of adding the solid catalyst component [A] and the organometallic compound component [B] into the polymerization system under the polymerization conditions is not particularly limited, and both may be added separately into the polymerization system or in advance. After reacting both, it may be added into the polymerization system. The ratio of the two to be combined is not particularly limited, but the amount of the organometallic compound [B] is preferably 1 mmol to 3,000 mmol with respect to 1 g of the solid catalyst component [A].

The organic aluminum compound [B] used together with the solid catalyst component [A] is not particularly limited, but specifically, trimethylaluminum, triethylaluminum, trin-propylaluminum, trin-butylaluminum, triiso-butylaluminum. , Tri-n-amyl aluminum, tri-iso-amyl aluminum, tri-n-hexyl aluminum, tri-n-octyl aluminum, tri-n-decyl aluminum and other trialkyl aluminum; diethylaluminum chloride, ethylaluminum dichloride, diiso-butylaluminum chloride Aluminum halides such as ethylaluminum sesquichloride and diethylaluminum bromide; alkoxyaluminum such as diethylaluminum ethoxide and diiso-butylaluminum butoxide; dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminum diethyl and the like. Syloxyalkylaluminum; and mixtures thereof are used, with trialkylaluminum being particularly preferred as it achieves the highest activity.

The solid catalyst component [A] and the organoaluminum compound may be added into the polymerization system under polymerization conditions, or may be mixed in advance prior to polymerization. The ratio of both components to be combined is defined by the molar ratio of Ti in the solid catalyst component [A] and Al in the organoaluminum compound [B], and is preferably Al / Ti = 0.3 to 1000.

As the polymerization solvent, a hydrocarbon solvent usually used for slurry polymerization is used. Specific examples thereof include aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as benzene, toluene and xylene; and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. These hydrocarbon solvents may be used alone or in combination of two or more. The polymerization temperature is usually in the range of room temperature to 100 ° C., preferably 50 ° C. to 90 ° C. The polymerization pressure is such that the polyethylene concentration in the slurry (mixed state of the solvent and the ethylene-based polymer particles) at the time of polymerization is less than 50%, preferably less than 40%. Usually, it is carried out in the range of normal pressure to 100 atm. The molecular weight of the obtained polymer can be adjusted by the presence of hydrogen in the polymerization system or by changing the polymerization temperature. Further, a method of producing by a vessel-type slurry polymerization method using a supported geometrically constrained single-site catalyst can also be preferably used. Further, in the step of separating the slurry into the ethylene polymer and the solvent, there is a step of volatilizing and removing the solvent, and further, the liquid content of the solvent with respect to the ethylene polymer is separated into less than 60 parts by weight before the volatilization step. To do.

The polyethylene resin composition thus obtained is particularly preferable in that the amount of comonomer introduced into the high molecular weight polyethylene resin component can be increased, so that the high molecular weight polyethylene resin component easily forms tie molecules.

(Other ingredients)
Additives, fillers and the like may be added to the polyethylene resin composition of the present embodiment, if necessary. The additives used are not particularly limited, but specifically, various antioxidants such as phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants; HALS-based photostabilizers and benzophenone-based additives. Various light stabilizers such as light stabilizers and benzotriazole UV absorbers; neutralizers such as fatty acid metal salts and hydrotalcites; heat stabilizers; weathering agents; pigments; lubricants such as calcium stearate can be used. it can. The filler is not particularly limited, and specific examples thereof include talc, silica, carbon, mica, calcium carbonate, magnesium carbonate, and wood flour. If desired, titanium oxide or organic pigments can be added in a masterbatch for use.
The various additives may be added as a masterbatch blended with / or one of the ethylene-based polymer A and the ethylene-based polymer B.
Further, the coloring component is preferably added as a masterbatch blended with the ethylene-based polymer B from the viewpoint of dispersibility. By adding in a masterbatch, additives and coloring components can be dispersed in the resin in advance, and improvement in dispersibility in the molded product at the time of molding can be expected.

[Use]
The polyethylene resin composition of the present embodiment can be used for various purposes, but has long-term creep characteristics particularly when used as a piping material (for example, one or more selected from the group consisting of piping and fittings). It is classified as PE100 described in the ISO9800 standard, has a high minimum guaranteed stress after 100 years, and is excellent in molding workability. Further, the piping material of the present embodiment is excellent in long-term characteristics, elongation characteristics, impact resistance, and moldability, and also tends to be excellent in surface properties such as longevity enhancement of SCG and surface roughening characteristics.

Here, "PE100" means that in the hot internal pressure creep test described in ISO9080, the stress-rupture time curve is measured at least 9000 at three different levels where the maximum temperature and the minimum temperature are separated by 50 ° C. or more. The LPL value of the value estimated by extrapolation of the minimum guaranteed stress after 50 years at 20 ° C. by multiple correlation averaging is 10 MPa or more and 11.19 MPa or less in the classification table specified in ISO12162. Refers to polyethylene having a minimum guaranteed stress of 10 MPa.

The "100-year warranty" refers to a polyethylene resin composition having a minimum guaranteed stress of 10 MPa or more due to extrapolation after 100 years at 20 ° C. by the same method as the above "PE100".
The polyethylene resin composition used in the present embodiment is superior in the longevity enhancement and surface properties of SCG as compared with the conventional resin composition for polyethylene piping material, and the piping material obtained from this is dramatically improved in long-term characteristics and produced. The sex is also very high.

The piping material is not particularly limited, and examples thereof include one or more selected from the group consisting of pipes and joints, and preferably water pipes or water joints. In particular, when the piping material of the present embodiment is used as a pipe, the pipe is excellent in long-term characteristics, rigidity, elongation characteristics, impact resistance, and molding processability under high temperature acceleration conditions, and is also excellent in surface properties. Further, when the piping material of the present embodiment is used as a joint, the joint has excellent long-term characteristics, rigidity, elongation characteristics, impact resistance, and surface properties under high temperature acceleration conditions, and also has excellent molding processability such as injection molding. Is also excellent.

Taking polyethylene pipe for water supply as an example of piping material for tap water, so-called chlorine-resistant water is used because when tap water is used in Japan, bubbles are generated by chlorine water and the surface layer is peeled off due to this. Performance is required. Usually, when producing polyethylene pipes and joints, they are usually provided in a colored form together with a coloring pigment in order to limit the use as a pipe. As described above, if the polyethylene pipe containing the coloring pigment and the resin for the joint have a large amount of ash (component derived from the coloring pigment), it is considered that the chlorine water resistance is lowered. Therefore, it is described in the polyethylene pipe for water supply of JIS K6762 that the ash content is limited to a predetermined amount or less. The ash content of the pipe and the joint of the pipe of the present embodiment is preferably 0.07% by mass or less, and more preferably 0.05% by mass or less.

〔Characteristic〕
The material for pipes is required to have excellent long-term fatigue characteristics of pipes. As a test for evaluating the long-term fatigue characteristics of a pipe, there is a repeated tensile fatigue test (FNTFT: Full-Notch Tensile Fitness Test). For this, a test piece obtained by cutting out a prism piece of 6 mm × 6 mm × 110 mm from a polyethylene pipe is used, and a notch having a depth of 0.5 mm is inserted in the center of the test piece with a sharp razor all around. Examples of the test device include a hydraulic fatigue tester manufactured by SUM Electro Mechanics (servo component FT series, model: FT-10 / SC-05-50-5B) and the like. The measurement conditions were a temperature condition of 80 ° C., the conditions were mode: ST / DY, center: -22.0 mm, amplitude: 19.0 mm, waveform: user wave, frequency: 2.00 Hz, and waveform was SINE. Repeated tensile stress (σ;) is applied to the test piece in the range of 3 to 20 MPa, and the number of breaks (N) with respect to the applied repeated tensile stress (σ) is measured. However, the applied stress is a swing from zero stress to the specified stress. The applied stress is obtained by dividing the applied load by the cross-sectional area of the sample after the test is completed. The cross-sectional area of the sample is obtained by subtracting the notch size from the size of the prism piece.

From σ and N obtained in such a test, a σ-LogN correlation diagram is created, and a correlation approximation straight line between σ and LogN is obtained. In general, the correlation approximate straight line is an approximate straight line in which a bending point (knee point) is observed in the region where the fracture type shifts from the ductile fracture mode (fracture mode on the high applied stress side) to the brittle fracture mode (fracture mode on the low applied stress side). The slope of is changed. Based on the approximate straight line of the σ-LogN correlation diagram, the number of times the knee point was observed and the number of repetitions until fracture at an applied stress of 10 MPa (N10 MPa) were obtained, and this was used as the long-term fatigue characteristic of the polyethylene resin composition. To do.

When the polyethylene resin composition of the present embodiment is used as a piping material, the number of times knee points are observed is 100,000 times or more, and the number of repetitions (N10 MPa) until fracture under an applied stress of 10 MPa is 100,000 times or more. Is preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.
The symbols and measurement methods shown in the present invention and the following Examples and Comparative Examples are as follows.

(1) MFR2.16:
Representing the melt index, the polyethylene resin on the low molecular weight side was measured by JIS K7210 under the conditions of a temperature of 190 ° C. and a load of 2.16 kg. The unit was g / 10 min.

(3) Density:
The low molecular weight polyethylene resin, the high molecular weight polyethylene resin, and the polyethylene resin composition were measured according to JIS K7112. The unit was kg / m ³ .

(4) Molecular weight distribution (Mw / Mn):
The polyethylene resin composition was measured by high temperature gel permeation chromatography (GPC), and was determined from the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in the obtained molecular weight distribution chart. Waters' Alliance GPCV2000 was used for high temperature GPC measurement, and Showa Denko's AT-807S (1) and Toso Co., Ltd.'s GMHHR-H (S) HT (2) were used for the columns. Conditions of orthodichlorobenzene (ODCB), column temperature 140 ° C., flow rate 1.0 mL / min, sample concentration 20 mg / solvent (ODCB) 10 mL, sample dissolution temperature 140 ° C., sample dissolution time 1 hour, connected in series. I went below.

(5) FNTFT:
(5-1) Pipe molding In the measurement of the physical properties of a pipe, the pipe was molded as follows using a polyethylene resin composition and subjected to a test. The pipe uses an extruder with a diameter of 65 mm (manufactured by Toshiba Plastic Engineering Co., Ltd.), melts the resin composition at 220 ° C., extrudes it into a cylinder from a die with an outer diameter of 80 mm and an inner diameter of 68 mm attached to the extruder, and a sizing plate in a sizing tank. A pipe that forms an outer diameter by passing through a pipe, cools the sizing tank water temperature at 25 ° C as primary cooling, and then cools at a water temperature of 20 ° C as secondary cooling in the next water tank after leaving the sizing tank. Was molded. This pipe was picked up by a pick-up machine so that the outer diameter / wall thickness ratio was 11, and a tubular pipe having an outer diameter of 63 mm and a wall thickness of 5.8 mm was formed.
(5-2) Sample Preparation The test sample is a prism piece of 6 mm × 6 mm × 110 mm cut out from a polyethylene pipe, and a notch with a depth of 0.5 mm is cut into the center of the test piece with a sharp razor. It was used.

(5-3) FNTFT measurement A hydraulic fatigue tester manufactured by Sam Electronics (Servo Component FT series, model: FT-10 / SC-05-50-5B) is used as the test device, and the test is performed under a temperature condition of 80 ° C. The conditions are mode: ST / DY, center: -22.0 mm, amplitude: 19.0 mm, waveform: user wave, frequency: 2.00 Hz, waveform is SINE, and repeated tensile stress (σ;) is applied. It was applied to the test piece in the range of 3 to 20 MPa, and the number of breaks (N) with respect to the applied repeated tensile stress (σ) was measured. However, the applied stress was a double swing from zero stress to the specified stress. The applied stress was determined by dividing the applied load by the cross-sectional area of the sample after the test was completed. The cross-sectional area of the sample was determined by subtracting the notch size from the size of the prism piece.

(5-4) Judgment of knee point From the obtained σ and N, a σ-LogN correlation diagram was created, and a correlation approximation straight line between σ and LogN was obtained. Correlation approximate straight lines are generally approximated by observing bending points (knee points) in the region where the fracture type transitions from ductile fracture mode (fracture mode on the high applied stress side) to brittle fracture mode (fracture mode on the low applied stress side). The slope of the straight line changes. The number of knee points observed was evaluated based on the approximate straight line of the σ-LogN correlation diagram.

(5-5) Number of breaks at 10 MPa The number of repetitions (N10 MPa) until breakage under an applied stress of 10 MPa was determined, and the long-term fatigue characteristics of polyethylene, which is a material for pipes, were evaluated.

(6) Pipe surface:
Visually check the surface of the pipe obtained in (5-1) above, and if there are stripes or irregularities due to melt fracture, it is ×, if it is slightly rough, it is △, and if it is smooth, it is ○. And said.

(7) Scratch on the surface of the pipe:
The durometer hardness (JIS K7215) of the pipe surface obtained in (5-1) above was measured.

(8) External stress resistance of pipe:
The flexural modulus (JIS K7171) of the pipe surface obtained in (5-1) above was measured.

(9) ESCR (Unit: hr):
According to JIS-K6761, the test piece was not annealed, and the water temperature in the constant temperature water tank was 50 ° C. As the test solution, a 10 wt% aqueous solution of polyoxyethylene nonylphenyl ether (Igepal CO-630) was used.

[Example 1]
[Catalyst preparation]
(Preparation of solid catalyst component [A])
(1) Synthesis of Magnesium-Containing Solid by Reaction with Chlorosilane Compound _{2740 mL of trichlorosilane (HSiCl 3} ) (component (ii)) as a 2 mol / L n-heptane solution is charged into a sufficiently nitrogen-substituted 15 L reactor. The temperature was kept at 65 ° C. with stirring, and the organic magnesium component (component (i) _{represented by the formula AlMg 6} (C ₂ H _{5 ) 3} (i-C ₄ H ₉ ) _10.8 (Oi-C ₄ H ₉ ) _{1.2 was added to this.} )) 7L of n-heptane solution (5 mol in terms of magnesium) was added over 1 hour, and the reaction was further carried out at 65 ° C. for 1 hour with stirring. After completion of the reaction, the supernatant was removed and washed with 7 L of n-hexane four times to obtain a solid slurry. The solid (A-1a) separated and dried was analyzed by solid per 1g, contained Mg8.62mmol, Cl17.1mmol, i- butoxy group _{(Oi-C 4 H 9)} 0.84mmol.

(2) Preparation of solid catalyst A slurry containing 500 g of the solid (A-1a) was mixed with 2,160 mL of an n-hexane solution of 1 mol / L of iso-butyl alcohol (component (A-2)) at 50 ° C. under stirring. Was reacted for 1 hour. After completion of the reaction, the supernatant was removed and washed once with 7 L of n-hexane to obtain a solid slurry (A-1b). The solid slurry (A-1b) was kept at 50 ° C., and 970 mL of a 1 mol / L n-hexane solution of diethylaluminum chloride (component (A-3)) was added under stirring and reacted for 1 hour. After completion of the reaction, the supernatant was removed and washed twice with 7 L of n-hexane to obtain a solid slurry (A-1c). Keep this solid slurry (A-1c) at 50 ° C., and add 270 mL of an n-hexane solution of 1 mol / L diethylaluminum chloride and 270 mL of an n-hexane solution of 1 mol / L titanium tetrachloride (component (A-4)). Reacted for 2 hours. After completion of the reaction, the supernatant was removed, and the mixture was washed 4 times with 7 L of n-hexane while maintaining the internal temperature at 50 ° C. to obtain a solid catalyst component (component [A]) as a hexane slurry solution. The chlorine ion concentration in the supernatant of this solid catalyst slurry solution was 2.5 mmol / L, and the aluminum ion concentration was 4.5 mmol / L.

(3) Polymerization A continuous slurry polymerization method using a polymerization catalyst containing the solid catalyst component [A] and triethylaluminum (component [B]) obtained above, and two-stage polymerization using two polymerization tanks connected in series. Was done. The comonomer used was 1-butene. Only ethylene is supplied as a monomer to the first-stage polymerization tank, and ^{polymerization is carried out at a temperature of 85 ° C., a pressure of 9.5 kg / cm 3} G, a hydrogen concentration of 70%, and a slurry concentration of 35%, and ethylene is used in the second stage. And 1-butene were supplied and polymerized at 70 ° C., 2.6 kg / cm ³ G, hydrogen concentration 4.8%, and 1-butene concentration 12.5%. The ratio of the production amount of the polyethylene resin component made of the ethylene homopolymer obtained in the first stage polymerization tank is 53 wt%, and the ratio of the production amount of the polyethylene resin component made of the copolymer obtained in the second stage polymerization tank is 47 wt%. By setting to%, a polyethylene-based polymer powder was obtained.
The powder obtained by the above polymerization was separated so that the liquid content was 45%, and then the solvent was volatilized and dried, and tri (2,4-di-t) was used as a secondary antioxidant with respect to 100 parts by mass of the powder. -Butylphenyl) phosphate 1,000 ppm, tetrakis (3- (4'-hydroxy-3', 5'-di-t-butylphenyl) propionate) methane as a heat-resistant stabilizer 1500 ppm, 2- (2- (4'-hydroxy-3', 5'-di-t-butylphenyl) propionate) as a weather resistant agent 3-t-Butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole 400ppm, calcium stearate 800ppm, Japan Steel Works TEX-44 type extruder (screw diameter 44mm, L / D = 42) setting An ethylene polymer A was obtained by extrusion granulation at a temperature of 200 ° C. and a resin extrusion rate of 40 kg / hr. The MFR 2.16 of the pellet was 0.09 g / 10 minutes and the density was 950 kg / m ³ .

Ethylene and 1-butene were supplied to the polymerization tank, polymerized at a temperature of 85 ° C., a pressure of 10 kg / cm ² G, and a hydrogen concentration of 58%. The obtained powder was dried, and calcium stearate was extruded and granulated at 1,000 ppm based on 100 parts by mass of the powder to obtain an ethylene polymer ^{having an MFR 2.16 of 42 g / 10 minutes and a density of 961 kg / m 3.} B was obtained.
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene-based polymer A and the ethylene-based polymer B at a ratio of 95: 5, and the physical properties of the pipe were measured. The results are shown in Table 1. When the surface of the pipe was visually confirmed, no rough skin was observed and the pipe was smooth.

[Example 2]
The first-stage polymerization tank was polymerized at a hydrogen concentration of 77%, ethylene and 1-butene were supplied to the second stage, and the polymerization was carried out at a hydrogen concentration of 2.7% and a 1-butene concentration of 11.5%. The ratio of the production amount of the low molecular weight component (A) made of the ethylene homopolymer obtained in the first stage polymerization tank is 52 wt%, and the proportion of the high molecular weight component (B) made of the copolymer obtained in the second stage polymerization tank is 52 wt%. ^{A powder having an MFR 2.16 of 0.79 g / 10 minutes and a density of 951 kg / m 3} was obtained in the same manner as in Example 1 except that the ratio of the production amount was set to 48 wt%. Further, this was extruded and granulated in the same manner as in Example 1 to obtain an ethylene polymer A having an MFR 2.16 of 0.30 g / 10 minutes and a density of 951 kg / m ^3. The results are shown in Table 1.

The same as in Example 1 except that the polymerization is carried out at a hydrogen concentration of 53% in the polymerization tank, the obtained powder is dried, and calcium stearate is extruded at 1,000 ppm and granulated with respect to 100 parts by mass of the powder. As a result, an ethylene polymer B having an MFR 2.16 of 42 g / 10 minutes and a density of 961 kg / m ^{3 was obtained.}
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene-based polymer A and the ethylene-based polymer B at a ratio of 95: 5, and the physical properties of the pipe were measured.

[Comparative Example 1]
A pipe having an outer diameter of 63 mm was formed using only the ethylene polymer A of Example 1, and the physical properties of the pipe were measured. The results are shown in Table 1.

[Comparative Example 2]
A pipe having an outer diameter of 63 mm was formed using only the ethylene polymer A of Example 2, and the physical properties of the pipe were measured. The results are shown in Table 1.

[Comparative Example 3]
An attempt was made to form a pipe having an outer diameter of 63 mm using only the ethylene-based polymer B of Example 1, but the pipe could not be formed. The results are shown in Table 1.

[Comparative Example 4]
An attempt was made to form a pipe having an outer diameter of 63 mm using only the ethylene-based polymer B of Example 2, but the pipe could not be formed. The results are shown in Table 1.

[Comparative Example 5]
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene polymer A of Example 1 and the ethylene polymer B of Example 2 at a ratio of 95: 5, and the physical properties of the pipe were measured. The results are shown in Table 1.

[Comparative Example 6]
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene polymer A of Example 2 and the ethylene polymer B of Example 1 at a ratio of 95: 5, and the physical properties of the pipe were measured. The results are shown in Table 1.

[Comparative Example 7]
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene polymer A of Example 1 and the ethylene polymer B of Example 1 at a ratio of 50:50, and the physical properties of the pipe were measured. The results are shown in Table 1.

[Comparative Example 8]
A pipe having an outer diameter of 63 mm was formed using pellets obtained by mixing the ethylene polymer A of Example 2 and the ethylene polymer B of Example 2 at a ratio of 50:50, and the physical properties of the pipe were measured. The results are shown in Table 1.

The piping material containing the polyethylene resin composition of the present invention is excellent in physical properties when used as a pipe or a joint, particularly long-term characteristics, moldability and surface properties, and is excellent in water supply, sewerage, agricultural pipe and various transportation pipe pipes and joints, etc. It is the best material for.

Claims (5)

A polyethylene resin composition containing 75 to 98 parts by mass of the following ethylene-based polymer A and 25 to 2 parts by mass of B.
(Ethylene polymer A)
Ethylene homopolymer, comprising a copolymer of及beauty et styrene and 1-butene, ethylene-based polymer satisfying the following (1) to (2);
(1) The melt flow rate (code D) (hereinafter referred to as "MFR2.16") is 0.04 g / 10 minutes or more and less than 0.15 g / 10 minutes.
(2) The molecular weight distribution is 15 or more and less than 40.
(Ethylene polymer B)
Comprises a copolymer of d styrene and 1-butene, 600 less than the ratio of MFR2.16 over 300 for MFR2.16 of ethylene polymer A, an ethylene polymer. A piping material containing the polyethylene resin composition according to claim 1. The piping material according to claim 2, wherein the knee point in the FNTFT is 100,000 times or more. The piping material according to claim 2 or 3, wherein in the FNTFT, the number of breaks at a stress of 10 MPa is 100,000 times or more. The piping material according to any one of claims 2 to 4, which is one or more selected from the group consisting of pipes and fittings.