JP2018131571A - Polyethylene resin composition and molded article and container thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyethylene resin composition capable of producing a molded article excellent in blow moldability, environmental stress-cracking resistance, impact resistance and excellent in appearance and to provide a molded article and a container comprising the same.SOLUTION: There is provided a polyethylene resin composition which comprises 10 mass% or more and 40 mass% or less of a specific polyethylene component (A), 5 mass% or more and 50 mass% of less of a specific polyethylene component (D) and 40 mass% or more and 85 mass% or less of a specific polyethylene component (E) and satisfies the following characteristics (1) to (5): (1) the MFR is 0.1 g/10 min or more and 1 g/10 min or less, (2) the HLMFR is 10 g/10 min or more and 50 g/10 min or less, (3) the melt flow rate ratio (HLMFR/MFR), which is a ratio of HLMFR to MFR, is 50 or more and 140 or less, (4) the density is 0.940 g/cmor more and 0.965 g/cmor less and (5) an inflection point of elongation viscosity caused by strain hardening is observed in a double logarithmic plot of elongation viscosity η(t) (unit: Pa sec) and elongation time t (unit: sec) measured at a temperature of 170°C and an elongation strain rate of 0.1 (unit: 1/sec.).SELECTED DRAWING: None

Description

  The present invention relates to a polyethylene resin composition, and a molded body and a container comprising the same.

In polyethylene hollow molding, injection molding, inflation molding, and extrusion molding, materials having good molding processability and physical properties are generally required. Especially for hollow bottles that are generally used as cosmetic containers, detergents, shampoos and rinse containers, or food containers such as edible oils, a polyethylene resin excellent in moldability, physical characteristics and chemical characteristics. Is widely used.
Furthermore, in recent years, there has been a demand for lighter and thinner hollow bottles in order to reduce costs. In these hollow bottle applications, particularly excellent properties such as environmental stress crack resistance and impact strength are required. Yes. As polyethylene that satisfies such requirements, those having a relatively high molecular weight and a wide molecular weight distribution are suitable.

Polyethylene polymerized using a chromium-based catalyst has a relatively wide molecular weight distribution and a molecular structure having a long-chain branched structure, which makes it easy to hollow-mold, specifically, a high melt tension and swell ratio. In addition, since the pinch-off part of the hollow bottle is easily thickened uniformly, it is generally widely used as a hollow molding material.
In addition, polyethylene that has been two-stage polymerized using a titanium-based catalyst can impart excellent environmental stress crack resistance by selectively copolymerizing a comonomer with a high molecular weight component, and low Since the molecular weight and molecular weight distribution can be adjusted by controlling the molecular weight component, it is generally widely used as a high environmental stress cracking grade suitable for hollow molding.
And the polyethylene polymer composition which mixed the polyethylene polymerized in two steps using the titanium-type catalyst and the polyethylene polymerized using the chromium-type catalyst, and made use of the mutual advantage is disclosed (for example, patent document) 1-7).
However, as the weight of containers and the diversification of designs continue to increase, it is necessary to increase the density of polyethylene if the rigidity of the container is to be secured while the container is thinned, that is, the amount of comonomer copolymerization is suppressed. Since there is a need and it is contrary to the maintenance of the environmental stress crack resistance, there is still a demand for a material that has an excellent balance between rigidity and environmental stress crack resistance and can cope with the thinning.

Therefore, a polyethylene resin composition composed of multiple components is disclosed which includes polyethylene using a metallocene catalyst and has improved rigidity and environmental stress crack resistance balance (see, for example, Patent Documents 8 to 13).
However, polyethylene using a metallocene-based catalyst has a relatively narrow molecular weight distribution and a molecular structure having a uniform comonomer distribution. Since the melt tension and the swell ratio are small, it is limited to the purpose of storing a specific content liquid or as a container having a specific shape.
Furthermore, as described in Patent Document 8, polyethylene using a metallocene-based catalyst has a low melting point and crystallization temperature corresponding to the same density, that is, it is easy to melt due to rigidity and is difficult to crystallize. The phenomenon that the speed is reduced is recognized, and there is a need to further increase the crystallization speed for high-speed molding.

And, including polyethylene using a metallocene catalyst, and further mixing polyethylene polymerized using a chrome catalyst, taking advantage of each other, it is excellent in balance between rigidity and environmental stress crack resistance and suitable for hollow moldability. The intended polyethylene polymer composition is disclosed (for example, Patent Documents 14 to 16).
However, Patent Document 14 discloses that a low gel is obtained by mixing a polyethylene using a high molecular weight metallocene catalyst and a polyethylene polymerized using a chromium catalyst, and having good mechanical strength and moldability and compatibility of each component. However, the composition has a very high viscosity and is not suitable for high-speed moldability, and its application is limited to a large hollow molded container.
In Patent Documents 15 and 16, a composition having both mechanical strength and formability is obtained by mixing a composition containing polyethylene using a high molecular weight metallocene catalyst and polyethylene polymerized using a chromium catalyst. Although the composition has been disclosed, the compatibility of each component has not been sufficiently studied, and the molecular weight of polyethylene using a high molecular weight metallocene catalyst is too high or contributes to compatibility. Since the blended amount of polyethylene polymerized using a chromium-based catalyst is small, sufficient compatibility cannot be obtained, and the appearance of the molded product is not always sufficient.

On the other hand, for the purpose of further enhancing the environmental stress crack resistance of polyethylene using a metallocene-based catalyst, an increase in molecular weight is extremely effective, while compatibility with other polyethylenes deteriorates, so polyethylene using a metallocene-based catalyst In the polyethylene resin composition containing, a resin design that achieves both compatibility and resistance to environmental stress cracking is important.
In view of such circumstances, while having the hollow moldability, high rigidity, impact resistance, etc. required for the conventional polyethylene resin composition for containers, the crystallization speed is fast, and high-speed molding high cycle can be achieved, Furthermore, there is a demand for a polyethylene material that is particularly excellent in the appearance of a molded product.

Therefore, the present applicant has found a polyethylene material having a high crystallization speed that can achieve further high-speed molding and high cycle while having hollow moldability, high rigidity, impact resistance, etc., and filed an application first. (Patent Documents 17 to 19). In Patent Documents 17 to 19, polymerized using a metallocene-based catalyst containing Ti, Zr or Hf with respect to 60 to 90% by mass of specific polyethylene, HLMFR and density are specific values, respectively, and long chain branching A polyethylene resin composition for containers which contains 10 to 40% by mass of a specific ethylene polymer having a structure and satisfies specific characteristics is disclosed.
In addition, in Japanese Patent Application Laid-Open No. 2004-228867, the present applicant has disclosed a polyethylene resin composition containing a specific amount of a polyethylene-based resin satisfying specific characteristics and a specific ethylene / α-olefin copolymer, and a molded product comprising the same. Disclosure.
However, the required performance required for products is increasing day by day, and further performance improvement is demanded in the problems of the prior art.

JP 59-196345 A JP 59-196346 A Japanese Unexamined Patent Publication No. 60-036547 JP 2004-059650 A JP 2004091739 A JP 2004-168817 A JP 2005-29881 A JP 08-283476 A Japanese Patent Laid-Open No. 08-283477 JP 2006-83370 A JP-A-11-106574 JP 11-199719 A JP 2009-7579 A JP 2003-213053 A Japanese Patent Laid-Open No. 11-138618 Special table 2009-506163 JP2013-204015A JP 2014-208749 A JP 2014-208750 A JP 2014-208817 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is excellent in hollow moldability, environmental stress crack resistance, impact resistance, thinner and lighter, and has a high crystallization speed. Excellent high-speed moldability, high cycle molding capability, high melt tension, excellent draw-down resistance, good pinch-off characteristics, hollow molding of complex shapes, and compatibility of resin components An object of the present invention is to provide a polyethylene resin composition that is high and has a particularly excellent appearance of a molded body, and a molded body comprising the same.

  As a result of intensive studies in order to solve the above problems, the present inventors contain a specific amount of a specific polyethylene component (A), a specific polyethylene component (D), and a specific polyethylene component (E), Polyethylene resin composition that satisfies specific characteristics is excellent in hollow moldability, environmental stress crack resistance and impact resistance, can be molded thinner and lighter, has a high crystallization speed, and has high moldability. Excellent, can be molded in a high cycle, has high melt tension, excellent draw-down resistance, good pinch-off characteristics, can be formed into a hollow complex shape, and has high compatibility with resin components. The present inventors have found that a polyethylene resin composition and a molded body comprising the same can be obtained, and the present invention has been completed.

That is, the polyethylene resin composition of the present invention comprises the following polyethylene component (A) of 10% by mass to 40% by mass, the following polyethylene component (D) of 5% by mass to 50% by mass, and the following polyethylene component (E). It contains 40 mass% or more and 85 mass% or less, and satisfies the following characteristics (1)-(5).
Polyethylene component (A); Characteristic (a1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.2 g / 10 min or more and 5 g / 10 min or less, and characteristic (a2): density is 0.915 g / cm ³ or more and 0.945 g / cm ³ or less, characteristic (a3): the following polyethylene component (B) and the following polyethylene component (C), (B) :( C) = 5: 95- Polyethylene containing at a ratio of 95: 5 (mass%).
Polyethylene component (B); Characteristic (b1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 kg is 0.2 g / 10 min or more and 2 g / 10 min or less, and characteristic (b2): density is 0.900 g / cm ³ or more 0.950 g / cm ³ polyethylene satisfy the following.
Polyethylene component (C); Characteristic (c1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.4 g / 10 min or more and 10 g / 10 min or less, and characteristic (c2): density is 0.900 g / cm ³ or more 0.970 g / cm ³ polyethylene satisfy the following.
Polyethylene component (D); Characteristic (d1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 2 g / 10 min or more and 20 g / 10 min or less. 945 g / cm ³ or more 0.965 g / cm ³ or less, the characteristics (d3): temperature 170 ° C., elongation strain rate 0.1: elongation viscosity measured at (in 1 / sec) eta (t) (unit: Polyethylene in which an inflection point of elongational viscosity due to strain hardening is observed in a logarithmic plot of Pa · second) and elongation time t (unit: second).
Polyethylene component (E); characteristic (e1): a melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg is 10 g / 10 min or more and 200 g / 10 min or less, and characteristic (e2): a density of 0.1. 960 g / cm ³ or more 0.980 g / cm ³ polyethylene satisfy the following.
Characteristic (1): MFR is 0.1 g / 10 min or more and 1 g / 10 min or less.
Characteristic (2): HLMFR is 10 g / 10 min or more and 50 g / 10 min or less.
Characteristic (3): Melt flow rate ratio (HLMFR / MFR) which is a ratio of HLMFR to MFR is 50 or more and 140 or less.
Characteristics (4): density of 0.940 g / cm ³ or more 0.965 g / cm ³ or less.
Characteristic (5): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed.

In the polyethylene resin composition of the present invention, it is preferable that the following property (6) is further satisfied.
Characteristic (6): Fracture time (FNCT) at 80 ° C. and 3.7 MPa by a full notch creep test is 285 hours or more.

In the polyethylene resin composition of the present invention, it is preferable that the following property (7) is further satisfied.
Characteristic (7): Tensile impact strength is 233 kJ / m ² or more.

  Moreover, according to this invention, the molded object created using the said polyethylene resin composition is provided.

  Moreover, according to this invention, the container created using the said polyethylene resin composition is provided.

The polyethylene resin composition of the present invention comprises a specific polyethylene component (B) which is a high molecular weight component, and a specific polyethylene component (C) having a low molecular weight relative to the component (B). A polyethylene component (A) having a structure obtained by multistage polymerization of (C), preferably a polyethylene component (A) having a structure obtained by multistage polymerization of component (B) and component (C) in this order; Since the polyethylene resin composition contains a specific amount of a specific polyethylene component (D) and a specific polyethylene component (E), for example, the viscosity of the high molecular weight component (B) is high and the molecular weight distribution is relatively Even in a narrow case, the component (C) present in the central part of the particle of the component (A) promotes dispersion of the component (B) when melt-kneaded with the material to be modified. Excellent There is an effect that a polyethylene resin composition.
Therefore, it contains relatively low molecular weight components with a relatively narrow molecular weight distribution, can be highly dispersed without significantly increasing the viscosity after blending with the material to be modified, hollow moldability, environmental stress crack resistance Excellent in heat resistance and impact resistance, can be molded thinner and lighter, has a high crystallization speed, excellent high-speed moldability, can be molded into a high cycle, has high melt tension, and is resistant to drawdown It is excellent in that it has excellent pinch-off characteristics, can be hollow-molded in a complex shape, has high compatibility with resin components, and can provide a polyethylene resin composition that is particularly excellent in the appearance of a molded product.
Moreover, according to this invention, there exists an effect that it can provide the molded object and container which are excellent in environmental stress crack resistance and impact resistance, are excellent in surface properties, and are excellent in an external appearance.

FIG. 1 is a plot diagram of typical elongation viscosity, and is a diagram for explaining a case where an inflection point of elongation viscosity is observed. FIG. 2 is a plot diagram of typical elongation viscosity, and is a diagram illustrating a case where an inflection point of elongation viscosity is not observed.

1. Polyethylene resin composition The polyethylene resin composition of the present invention comprises 10% by mass to 40% by mass of the following polyethylene component (A), 5% by mass to 50% by mass of the following polyethylene component (D), and the following polyethylene component (E 40% by mass or more and 85% by mass or less, and satisfy the following characteristics (1) to (5).
Polyethylene component (A); Characteristic (a1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.2 g / 10 min or more and 5 g / 10 min or less, and characteristic (a2): density is 0.915 g / cm ³ or more and 0.945 g / cm ³ or less, characteristic (a3): the following polyethylene component (B) and the following polyethylene component (C), (B) :( C) = 5: 95- Polyethylene containing at a ratio of 95: 5 (mass%).
Polyethylene component (B); Characteristic (b1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 kg is 0.2 g / 10 min or more and 2 g / 10 min or less, and characteristic (b2): density is 0.900 g / cm ³ or more 0.950 g / cm ³ polyethylene satisfy the following.
Polyethylene component (C); Characteristic (c1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.4 g / 10 min or more and 10 g / 10 min or less, and characteristic (c2): density is 0.900 g / cm ³ or more 0.970 g / cm ³ polyethylene satisfy the following.
Polyethylene component (D); Characteristic (d1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 2 g / 10 min or more and 20 g / 10 min or less. 945 g / cm ³ or more 0.965 g / cm ³ or less, the characteristics (d3): temperature 170 ° C., elongation strain rate 0.1: elongation viscosity measured at (in 1 / sec) eta (t) (unit: Polyethylene in which an inflection point of elongational viscosity due to strain hardening is observed in a logarithmic plot of Pa · second) and elongation time t (unit: second).
Polyethylene component (E); characteristic (e1): a melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg is 10 g / 10 min or more and 200 g / 10 min or less, and characteristic (e2): a density of 0.1. 960 g / cm ³ or more 0.980 g / cm ³ polyethylene satisfy the following.
Characteristic (1): MFR is 0.1 g / 10 min or more and 1 g / 10 min or less.
Characteristic (2): HLMFR is 10 g / 10 min or more and 50 g / 10 min or less.
Characteristic (3): Melt flow rate ratio (HLMFR / MFR) which is a ratio of HLMFR to MFR is 50 or more and 140 or less.
Characteristics (4): density of 0.940 g / cm ³ or more 0.965 g / cm ³ or less.
Characteristic (5): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed.

<Polyethylene component (A)>
Characteristics (a1)
The polyethylene component (A) used in the present invention satisfies the following characteristics (a1) to (a3).
Characteristic (a1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.2 g / 10 min or more and 5 g / 10 min or less.
Characteristic (a2): Density is 0.915 g / cm ³ or more and 0.945 g / cm ³ or less.
Characteristic (a3): The following polyethylene component (B) and the following polyethylene component (C) are included in a ratio of (B) :( C) = 5: 95 to 95: 5 (mass%).
Polyethylene component (B); Characteristic (b1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 kg is 0.2 g / 10 min or more and 2 g / 10 min or less, and characteristic (b2): density is 0.900 g / cm ³ or more 0.950 g / cm ³ polyethylene satisfy the following.
Polyethylene component (C); Characteristic (c1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.4 g / 10 min or more and 10 g / 10 min or less, and characteristic (c2): density is 0.900 g / cm ³ or more 0.970 g / cm ³ polyethylene satisfy the following.

Characteristics (a1)
The polyethylene component (A) used in the present invention has a melt flow rate (HLMFR) of 0.2 g / 10 min or more and 5 g / 10 min or less at a temperature of 190 ° C. and a load of 21.6 kg from the point that the effects of the present invention are exhibited. Choose what is. The HLMFR of the polyethylene component (A) is preferably in the range of 0.3 g / 10 min or more and 1.0 g / 10 min or less, more preferably 0.4 g / 10 min or more and 0.7 g / 10 min or less. If this HLMFR is 0.2 g / 10 min or more, in the final resin composition, the HLMFR can be within the specified range, the fluidity is improved, and the compatibility is improved. Can be. On the other hand, when the HLMFR is 5 g / 10 min or less, the final resin composition can achieve the environmental stress crack resistance and can improve the long-term durability of the molded product.
In addition, in this specification, HLMFR of a polyethylene component and a polyethylene resin composition can be measured based on JISK6922-2: 1997.
The HLMFR of the polyethylene component (A) can be adjusted mainly by the amount of hydrogen and the polymerization temperature during the polymerization of the polyethylene component (A).

Characteristic (a2)
As the polyethylene component (A) used in the present invention, a polyethylene component having a density of 0.915 g / cm ³ or more and 0.945 g / cm ³ or less is selected from the point of achieving the effects of the present invention. The density of polyethylene component (A) is preferably 0.920 g / cm ³ or more 0.935 g / cm ³ or less, still more preferably 0.922 g / cm ³ or more 0.930 g / cm ³ or less. If the density is 0.915 g / cm ³ or more, the density range in the final resin composition can be achieved, and desired rigidity can be obtained. On the other hand, when the density is 0.945 g / cm ³ or less, desired environmental stress cracking resistance can be obtained in the final resin composition.
In addition, in this specification, the density of a polyethylene component and a polyethylene resin composition can be measured based on JISK6922-1,2: 1997.
The density of the polyethylene component (A) can be adjusted mainly by the amount of α-olefin during polymerization of the polyethylene component (A).

Characteristic (a3)
The polyethylene component (A) used in the present invention comprises the following polyethylene component (B) and the following polyethylene component (C) in a ratio of (B) :( C) = 5: 95 to 95: 5 (mass%). It is multimodal polyethylene to be included, and the proportion of the polyethylene component (B) is preferably 15 to 85% by mass, more preferably 35 to 75% by mass. Further, the polyethylene component (A) is preferably obtained by multistage polymerization, and more preferably obtained by multistage polymerization of the component (B) and the component (C) in this order.
Multimodal polyethylene refers to a polyethylene composition having two or more components. Each component differs in molecular weight, monomer composition, density, long chain branching concentration, long chain branching distribution or a combination thereof. In addition, the multimodal polyethylene may be composed of a plurality of different molecular weight fractions, may be composed of fractions resulting in a plurality of different comonomer contents, or may be composed of a plurality of different polymerization conditions. It may contain the polyethylene fraction produced below. The “multimodal” prefix “multi” means that the number of polymer fractions constituting the polyethylene composition is plural. Thus, for example, a composition consisting of two fractions is called “bimodal” and a composition consisting of three fractions is called “trimodal”.
Such a molecular weight distribution curve of multimodal polyethylene, ie a graph of the polymer weight fraction as a function of its molecular weight, shows a shape that has two or more maxima, or a shape that can be divided into multiple molecular weight distribution curves. Things.

<Polyethylene component (B)>
The polyethylene component (B) is a polyethylene that satisfies the following characteristics (b1) to (b2).
Characteristic (b1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.3 g / 10 min or more and 1 g / 10 min or less.
Characteristics (b2): density of 0.900 g / cm ³ or more 0.950 g / cm ³ or less.

Characteristic (b1)
The high load melt flow rate (HLMFR, temperature 190 ° C., load 21.60 kg) of the component (B) in the present invention needs to be 0.2 to 2 g / 10 min. Preferably it is 0.3-0.9 g / 10min, More preferably, it is 0.3-0.8 g / 10min. When HLMFR is 0.2 g / 10 min or more, desired mixing properties can be obtained. On the other hand, when the HLMFR is 2 g / 10 min or less, desired impact strength and the like can be obtained.
The HLMFR of the component (B) can be adjusted mainly by the amount of hydrogen during the production of the component (B).

Characteristic (b2)
The density of the component (B) in the present invention must be 0.900~0.950g / cm ^3, preferably 0.910 to 0.935 g / cm ^3, more preferably 0.915 to 0 935 g / cm ³ . A desired rigidity is obtained when the density is 0.900 g / cm ³ or more. On the other hand, when the density is 0.950 g / cm ³ or less, desired impact strength and the like can be obtained.
The density of a component (B) can be adjusted with the quantity of the alpha olefin at the time of manufacture of a component (B) mainly.

<Polyethylene component (C)>
The polyethylene component (C) is a polyethylene that satisfies the following characteristics (c1) to (c2).
Characteristic (c1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.4 g / 10 min or more and 10 g / 10 min or less.
Characteristics (c2): density of 0.900 g / cm ³ or more 0.970 g / cm ³ or less.
In addition, a polyethylene component (C) is polyethylene which has a low molecular weight with respect to a polyethylene component (B).

Characteristic (c1)
The high load melt flow rate (HLMFR, temperature 190 ° C., load 21.60 kg) of component (C) in the present invention needs to be 0.4 to 10 g / 10 min. Preferably it is 0.4-3g / 10min, More preferably, it is 0.4-2g / 10min. When HLMFR is 0.4 g / 10 min or more, desired mixing properties can be obtained. On the other hand, when the HLMFR is 10 g / 10 min or less, the desired dispersibility of the component (B) can be obtained.
The HLMFR of the component (C) can be adjusted mainly by the amount of hydrogen during the production of the component (C).

Characteristic (c2)
The density of the component (C) in the present invention must be 0.900~0.970g / cm ^3, preferably 0.910~0.965g / cm ^3, more preferably 0.915 to 0 965 g / cm ³ . A desired rigidity is obtained when the density is 0.900 g / cm ³ or more. On the other hand, when the density is 0.970 g / cm ³ or less, desired impact strength and the like can be obtained.
The density of a component (C) can be adjusted with the quantity of the alpha olefin at the time of manufacture of a component (C) mainly.

<Method for producing polyethylene component (A)>
The polyethylene component (A) used in the present invention is preferably obtained by multistage polymerization of the component (B) and the component (C), from the aspect of characteristics and work surface of the obtained resin composition. In view of this, it is preferable that the component (B) and the component (C) are obtained by multistage polymerization in this order. The multistage polymerization is more preferably a continuous multistage polymerization.
In general, the dispersibility of a high molecular weight component is influenced by the viscosity difference between components adjacent to the high molecular weight component at the time of mixing. The smaller the viscosity difference, the better the dispersibility of the high molecular weight component.
The polyethylene resin composition of the present invention satisfies the above specific physical properties and is produced by a specific production method in which the component (B) is first polymerized and then the specific component (C) is produced by multistage polymerization. Thus, the polyethylene component before melt kneading by the component (C) produced after the previously produced high molecular weight component (B) present on the outer surface of the polyethylene component (A) particles is present in the center. It is presumed that it is spread and diffused in the state of particles of (A).
The polyethylene component (A) has a high probability that the component (B) is present on the outer surface of the polyethylene component (A) particles, and the component (C) has a high probability in the center of the polyethylene component (A) particles. Those having an existing structure are preferred. The mass ratio of the component (B) and the component (C) in the polyethylene component (A) is as described above.
As a component adjacent to the high molecular weight component (B) at the time of melt kneading with the material to be reformed, the material to be reformed can be considered in addition to the component (C), but the component (B) with respect to the dispersibility of the component (B) ) And the difference in viscosity between the materials to be modified are considered to be small compared to the effect of the difference in viscosity between component (B) and component (C). This is because the component (B) has a high affinity with the component (C) produced by continuous polymerization, so the viscosity ratio with the component (C) is higher than the viscosity ratio with the material to be modified later. This is thought to be strongly influenced.
Thus, in the molded article of the composition using the polyethylene resin composition of the present invention, the component (B) which is a high molecular weight component is highly dispersed, the generation of high molecular weight gel is also suppressed, and the appearance is impaired. Therefore, it is considered that the mechanical strength such as impact strength and rigidity of the molded product can be highly improved.
Here, “highly dispersed” specifically means that when the fish eye is measured by the measurement method described below (<Mixability evaluation method>), the evaluation is 4 or less. Say.
Therefore, the molded product of the composition using the polyethylene resin composition of the present invention can suppress the generation of high molecular weight gel and contains a relatively small amount of high molecular weight components having a relatively narrow molecular weight distribution in order to improve physical properties. Even though the viscosity of the polyethylene resin composition as a whole of the present invention is far from that of the high molecular weight component, when formed into a molded product, unevenness due to high molecular weight gel resulting from poor dispersibility does not occur, and the appearance is It is estimated to be excellent.

<Mixability evaluation method>
The fish eye of the polyethylene resin composition of the present invention can be measured by the following method.
The sample to be measured is compressed at a temperature of 180 ° C. and a pressure of 100 kgf / cm ² in the first step by a mold having a thickness of 0.35 mm and two press molding machines for compression and cooling. In the second step, a press sheet having a thickness of 0.4 mm is formed by cooling at a temperature of 30 ° C. and a pressure of 50 kgf / cm ² . This press sheet is cut into test pieces of 50 × 50 × 0.4 mm.
Next, the test piece is stretched with a biaxial stretching apparatus. As the biaxial stretching apparatus, for example, a biaxial stretching apparatus SS-60 manufactured by Shibayama Scientific Instruments Co., Ltd. is used, and the test piece is stretched twice at a temperature of 150 ° C. and a stretching speed of 60 mm / min. The stretching procedure is such that a 1 cm portion of the end of the test piece is chucked by the four chuck portions of the biaxial stretching apparatus, and the unchucked central portion of the press sheet is set to a 30 × 30 mm square. Thereafter, the test piece is heated to a temperature of 130 to 170 ° C., biaxially stretched until the distance between diagonal chucks becomes 60 mm, and a sheet in which the center portion not chucked is stretched about twice is obtained. create.
The surface of a square area of 30 × 30 mm located almost at the center of the biaxially stretched sheet is imaged using a reflective 3D microscope. The magnification of the 3D microscope is 10 times, and the range (one field of view) of the photographed sheet is 10 × 10 mm. In order to increase the reliability of the measurement, the measurement is performed four times with respect to one sample in a 30 × 30 mm square range located in the center of the sheet so that the respective fields of view do not overlap. The photographed image is binarized into a fish eye part and a non-fish eye part (a uniform matrix part). The condition of the binarization process can be appropriately searched and set by the measurer.
The binarized image is read by a scanner and digitized to obtain image data.
The resolution of the scanner is 600 dpi or more, preferably 900 dpi or more. For example, a scanner GT-F670 (manufactured by EPSON, resolution: 4800 dpi) can be used as the scanner.
The analysis of image data is realized by, for example, a personal computer and a software program executed on the personal computer. By processing the image data with a personal computer, it is possible to calculate characteristic parameters such as the area of each particle, the perimeter, the major / minor diameter ratio, the particle diameter, and the circularity. In this case, the feature parameters can be calculated using commercially available image processing software. As commercially available image analysis software, for example, WinROOF manufactured by Mitani Corporation can be used.
The image data defines a threshold value for the color arrangement of the black and white portions of the image, and is binarized and processed at an appropriate level. The condition of the binarization process can be appropriately searched and set by the measurer.
Image analysis calculates the area, perimeter, maximum length, maximum length vertical length (length in the direction perpendicular to the maximum length), etc. of each particle using known means, and the various parameters of the particles are calculated for each particle. Can be calculated. The calculated parameters are the equivalent circle diameter of the particle (diameter of the circle with the area equal to the area of the image of the particle), circularity (ratio of the circumference of the circle with the area equal to the area of the image of the particle and the circumference of the image) ), Aspect ratio (ratio of maximum length of image of particle and maximum length of vertical length).
The equivalent circle diameter is equivalent circle diameter = (area value of particle image / π) ^1/2 × 2, and the circularity is circularity = (peripheral length of circle having area value of particle image) / ( The peripheral length of the particle image) and the aspect ratio are calculated by (maximum length of the particle image) / (maximum vertical length of the particle image).
In the present invention, as the measurement of fish eyes, the area ratio of fish eyes in the image is obtained. For the area ratio of one sample of fish eye, the average value of the measured values obtained for each of four fields of view taken on one test piece is calculated.
For example, when the area ratio of the fish eye in the image is 0.2% or less, “1”, when it is more than 0.2 to 0.5%, “2”, and more than 0.5 to 3.0% The case is “3”, the case of over 3.0 to 5.0% is “4”, the case of over 5.0 to 10.0% is “5”, and the case of over 10.0% is “6” Can be evaluated.

  According to the above measurement method, for example, a finer fish eye can be measured than when evaluated by the gloss of an injection-molded product, and therefore, it can be used as an advanced evaluation of dispersibility.

As a kind of polyethylene component of a component (B) and a component (C), it is preferable that it is a homopolymer of ethylene and / or a copolymer of ethylene and an alpha olefin, ie, it is an ethylene-type polymer. However, in order to further improve the mechanical strength, the component (B) and the component (C) are more preferably an ethylene / α-olefin copolymer.
Component (B) and component (C) are homopolymerization of ethylene or ethylene and an α-olefin having 3 to 12 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1- It can be obtained by copolymerization with pentene, 1-octene or the like. Also, copolymerization with a diene for the purpose of modification is possible. Examples of the diene compound used at this time include butadiene, 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene, and the like.
In addition, although the comonomer content rate in the case of superposition | polymerization of a component (B) and a component (C) can be selected arbitrarily, for example, in the case of copolymerization with ethylene and a C3-C12 alpha olefin. The α-olefin content in the ethylene / α-olefin copolymer is 0 to 40 mol%, preferably 0 to 30 mol%.
The ethylene polymer used in the polyethylene resin composition of the present invention may be one using ordinary ethylene as a raw material, or one using ethylene obtained from plant-derived ethanol or the like as a raw material.

Although the polymerization catalyst of the polyethylene component of component (B) and component (C) is not particularly limited, a metallocene catalyst or a Ziegler catalyst is preferably used from the balance of HLMFR and density in the scope of the present invention, and more preferably metallocene. A catalyst is used.
The Ziegler catalyst includes a Ziegler-Natta catalyst as an olefin coordination polymerization catalyst comprising a combination of a transition metal compound and a typical metal alkyl compound, in particular, a solid catalyst component in which a titanium compound is supported on a magnesium compound and an organoaluminum compound. See the so-called combined Mg-Ti Ziegler catalysts (for example, “Catalyst Application Dictionary; Issued by the 2004 Industrial Research Committee”, “Application System Diagram—Transition of Olefin Polymerization Catalysts; Published by the Invention Association of 1995”). ) Is suitable because it is inexpensive, highly active and excellent in polymerization process suitability.
Among them, an inert carrier material-supported Mg / Ti catalyst as described in JP 54-142192 A and JP 54-148093 A, for example, anhydrous MgCl ₂ in tetrahydrofuran and TiCl ₃ or A catalyst obtained by impregnating porous silica previously treated with triethylaluminum with a uniform mixed solution of TiCl ₄ and drying and drying, or an organic aluminum as described in JP-A-63-117019. A catalyst obtained by subjecting a Mg / Ti catalyst to olefin prepolymerization in the presence of, for example, a solid component obtained by the reaction of MgCl ₂ , Ti (OnBu) ₄ and methylhydropolysiloxane is mixed with TiCl ₄ and methyl hydrodiene. The catalyst obtained by introducing the mixed solution of empolysiloxane is treated with triethylaluminum. Ethylene prepolymerized prepolymerized catalyst thus obtained, and the like.
Further, a catalyst component containing a low-valence titanium atom obtained by reacting a magnesium-aluminum complex and a tetravalent titanium compound as described in JP-A-60-195108 and organoaluminum A catalyst for olefin polymerization in combination with a compound, ethylaluminum sesquichloride, etc. to a homogeneous mixture of magnesium ethoxide, tri-n-butoxymonochlorotitanium, n-butanol as described in JP-A-56-61406, etc. Examples thereof include a solid catalyst obtained by dropping, a solid catalyst for olefin polymerization containing magnesium, halogen, titanium and an electron donor as described in JP-A No. 2001-139635.
In the present invention, an ethylene polymer having a narrow molecular weight distribution or copolymer composition distribution can be produced with high activity, and is preferably selected from the group of magnesium compounds represented by the following general formula (a). And a Mg—Ti Ziegler catalyst characterized by comprising at least a compound selected from the group of titanium compounds represented by the following general formula (b).

General formula (a): Mg, MgO, or MgX ¹ _m R ¹ _n (OR ² ) _2-mn
Here, X ¹ is a halogen atom, preferably a chlorine atom, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 6 carbon atoms, more preferably methyl, ethyl, propyl, butyl, R ² is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 6 carbon atoms, more preferably methyl, ethyl, propyl, butyl. m and n are numbers satisfying 0 ≦ m ≦ 2, 0 ≦ n ≦ 2, and 0 ≦ m + n ≦ 2, respectively.

An example of a preferable embodiment of the general formula (a) is Mg, MgO, MgClR ¹ _n (OR ² ) _1-n , MgCl ₂ , MgX ¹ _m R ¹ _1-m (OR ² ), Mg (OR ² ) ₂ However, 0 ≦ m ≦ 1, 0 ≦ n ≦ 1, and an example of a more preferable embodiment is Mg, MgO, MgClR ¹ , MgCl ₂ , MgX ¹ (OR ² ), Mg (OR ² ) ₂ , An example of a particularly preferred embodiment is MgCl ₂ or Mg (OR ² ) ₂ . However, the definitions of R ¹ , R ² and X ¹ are as described above.

Specifically, the magnesium compound contained in the said general formula (a) can be enumerated below.
_{(1) Mg, MgO, MgF} 2, MgCl 2, MgBr 2, MgI 2, MgClF, MgBrCl, MgClI like,
(2) Mg (CH ₃ ) ₂ , Mg (C ₂ H ₅ ) ₂ , Mg (C ₃ H ₇ ) ₂ , Mg (C ₄ H ₉ ) ₂ , Mg (C ₆ H ₁₃ ) ₂ , Mg (C _{8 H 17) 2, Mg (C} 10 H 21) 2, Mg (C 3 H 5) 2, Mg (C 6 H 11) 2, Mg (C 6 H 5) 2, Mg (C 6 H 4 -CH 3 ) ₂ , Mg (C ₆ H ₄ -C ₂ H ₅ ) ₂ , Mg (C ₆ H ₄ -C ₄ H ₉ ) ₂ , Mg (C ₆ H ₃ (CH ₃ ) ₂ ) ₂ , Mg (CH ₂ — _{C 6 H 5) 2, Mg} (C 2 H 4 -C 6 H 5) 2, Mg (CH 3) (C 2 H 5), Mg (C 2 H 5) (C 4 H 9), Mg (CH _{3) (C 4 H 9)} , Mg (C 4 H 9) (C 6 H 5) or the like,
_{(3) Mg (OH) 2} , Mg (OCH 3) 2, Mg (OC 2 H 5) 2, Mg (OC 3 H 7) 2, Mg (OC 4 H 9) 2, Mg (OC 6 H 13) ₂ , Mg (OC ₆ H ₁₁ ) ₂ , Mg (OC ₆ H ₅ ) ₂ , Mg (OCH ₂ C ₆ H ₅ ) ₂ , Mg (OH) (OC ₂ H ₅ ), Mg (OC ₂ H ₅ ) ( _{OC 4 H 9), Mg (} OC 6 H 4 CH 3) 2 or the like,
Mg (C ₂ H ₅ ) Cl, Mg (C ₂ H ₅ ) Br, Mg (C ₂ H ₅ ) I, Mg (C ₄ H ₉ ) Cl, (4) Mg (C ₄ H ₉ ) Br, Mg ( C ₄ H ₉ ) I etc.
(5) Mg (OH) Cl , Mg (OH) Br, Mg (OH) I, Mg (OC 2 H 5) Cl, Mg (OC 2 H 5) Br, Mg (OC 2 H5) I, Mg (OC ₄ H ₉ ) Cl, Mg (OC ₄ H ₉ ) Br, Mg (OC ₄ H ₉ ) I, etc.
_{(6) Mg (C 2 H} 5) (OC 2 H 5), Mg (C 2 H 5) (OC 3 H 7), Mg (C 2 H 5) (OC 4 H 9), Mg (C 2 H ₅ ) (OC ₆ H ₁₃ ) etc.

Among them, Mg, MgO, MgCl ₂ , MgBr ₂ , MgI ₂ , Mg (CH ₃ ) ₂ , Mg (C ₂ H ₅ ) ₂ , Mg (C ₃ H ₇ ) ₂ , Mg (C ₄ H ₉ are preferable. ) ₂ , Mg (C ₂ H ₅ ) (C ₄ H ₉ ), Mg (OCH ₃ ) ₂ , Mg (OC ₂ H ₅ ) ₂ , Mg (OC ₃ H ₇ ) ₂ , Mg (OC ₄ H ₉ ) ₂ Mg (OC ₆ H ₁₃ ) ₂ , Mg (C ₂ H ₅ ) Cl, Mg (C ₂ H ₅ ) Br, Mg (C ₂ H ₅ ) I, Mg (C ₄ H ₉ ) Cl, Mg (C ₄ H ₉ ) Br, Mg (C ₄ H ₉ ) I, Mg (OC ₂ H ₅ ) Cl, Mg (OC ₂ H ₅ ) Br, Mg (OC ₂ H ₅ ) I, more preferably MgO, MgCl ₂ , Mg (C ₂ H ₅ ) ₂ , Mg (C ₄ H ₉ ) ₂ , Mg (C ₂ H ₅ ) (C ₄ H ₉ ), Mg (OCH ₃ ) ₂ , Mg (OC ₂ H ₅ ) ₂ , Mg (OC ₃ H ₇ ) ₂ , Mg (OC ₄ H ₉ ) ₂ , particularly preferably MgCl ₂ , Mg (C ₂ H ₅ ) ₂ , Mg (C ₄ H ₉ ) ₂ , Mg (C ₂ H ₅ ) (C ₄ H ₉ ), Mg (OC ₂ H ₅ ) ₂ .

Formula _{^{(b): TiX 2 p (}} OR 3) 4-p
Here, X ² is a halogen atom, preferably a chlorine atom, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 6 carbon atoms, more preferably methyl, ethyl, propyl, It is butyl, and p is a number that satisfies 0 ≦ p ≦ 4.
An example of a preferable aspect of the general formula (b) is TiCl (OR ³ ) ₃ , TiCl ₂ (OR ³ ) ₂ , TiCl ₃ (OR ³ ), TiCl ₄ , and an example of a more preferable aspect is TiCl (OR ³⁾ _3, is TiCl _4.
However, the definition of R ³ is as described above. When p = 0, that is, when Ti (OR ³ ) ₄ is used, a halogenating agent is used in combination.
Here, the halogenating agent is not particularly limited as long as it is a compound having an action of substituting one or more hydrocarbon oxy groups (OR ³ ) of Ti (OR ³ ) ₄ with halogen. Among the magnesium compounds, aluminum compounds, and silicon compounds described in the above, compounds containing halogen atoms, or halogens in elemental state, hydrogen halides such as hydrogen chloride, haloalkanes such as chloroform, thionyl chloride, phosphorus oxychloride, Oxyhalides such as acyl chloride, non-metallic halides such as phosphorus trichloride, phosphorus pentachloride, ammonium chloride, boron chloride, sodium chloride, calcium chloride, zirconium chloride, vanadium chloride, chromium chloride, manganese chloride, iron chloride, chloride Metal halides such as nickel, tin chloride, and zinc chloride are used.

Specific examples of the titanium compound included in the general formula (b) can be listed below.
(1) TiF ₄ , TiCl ₄ , TiBr ₄ , TiI ₄ , TiFCl ₃ , TiBrCl ₃ , TiBr ₂ Cl ₂ , TiBr ₃ Cl, TiBrCl ₂ I, etc.
(2) Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (OC ₃ H ₇ ) ₄ , Ti (OC ₄ H ₉ ) ₄ , Ti (OC ₆ H ₁₃ ) ₄ , Ti (OC ₆₎ H ₁₁ ) ₄ , Ti (OC ₆ H ₅ ) ₄ , Ti (OC ₈ H ₁₇ ) ₄ , Ti (OC ₁₀ H ₂₁ ) ₄ , Ti (OCH ₂ C ₆ H ₅ ) ₄ , Ti (OCH ₂ C ₃ H ₅ ) ₄ , Ti (OCH ₂ C ₆ H ₁₁ ) ₄ , Ti (OC ₃ H ₅ ) ₄ , Ti (OC ₂ H ₅ ) (OC ₄ H ₉ ) ₃ , Ti (OC ₂ H ₅ ) ₂ (OC _{4 H 9) 2, Ti (OC} 2 H 5) 3 (OC 4 H 9), Ti (OC 6 H 4 CH 3) 4, Ti (OC 2 H 5) (OC 4 H 9) (OC 6 H 13) _2nd ,
(3) Ti (OCH ₃ ) Cl ₃ , Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OCH ₃ ) ₃ Cl, Ti (OC ₂ H ₅ ) Cl ₃ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₃ Cl, Ti (OC ₂ H ₅ ) (OC ₄ H ₉ ) Cl ₂ , Ti (OC ₂ H ₅ ) Br ₃ , Ti (OC ₂ H ₅ ) I ₃ , Ti (OC ₂ H _{5) Cl 2 Br, Ti (} OC 2 H 5) Cl 2 I, Ti (OC 2 H 5) ClBrI, Ti (OC 3 H 7) Cl 3, Ti (OC 3 H 7) 2 Cl 2, Ti (OC _{3 H 7) 3 Cl, Ti} (OC 4 H 9) Cl 3, Ti (OC 4 H 9) 2 Cl 2, Ti (OC 4 H 9) 3 Cl, Ti (OC 4 H 9) Br 3, Ti ( OC ₄ H ₉ ) I ₃ , Ti (OC ₅ H ₁₁ ) ₃ Cl, Ti (OC ₆ H ₁₃ ) ₃ Cl, Ti (OC ₆ H ₅ ) ₃ Cl, Ti (OC ₆ H ₅ ) ₂ Cl ₂ , Ti (OC ₆ H ₅ ) Cl _3, etc.

Among them, TiCl ₄ , Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (OC ₃ H ₇ ) ₄ , Ti (OC ₄ H ₉ ) ₄ , Ti (OC ₆ H ₁₃ ) are preferable. ₄ , Ti (OC ₆ H ₁₁ ) ₄ , Ti (OC ₆ H ₅ ) ₄ , Ti (OCH ₃ ) Cl ₃ , Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OCH ₃ ) ₃ Cl, Ti (OC ₂ H ₅ ) Cl ₃ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₃ Cl, Ti (OC ₃ H ₇ ) Cl ₃ , Ti (OC ₃ H ₇ ) ₂ Cl ₂ , Ti (OC _{3 H 7) 3 Cl, Ti} (OC 4 H 9) Cl 3, Ti (OC 4 H 9) 2 Cl 2, Ti (OC 4 H 9) 3 Cl, Ti (OC 5 H 11) 3 Cl, Ti ( _{OC 6 H 13) 3 Cl,} Ti (OC 6 H _{) 3 Cl, Ti (OC 6} H 5) 2 Cl 2, Ti (OC 6 H 5) is Cl _3, more _{preferably, TiCl 4, Ti (OC 2} H 5) 4, Ti (OC 3 H 7) ₄ , Ti (OC ₄ H ₉ ) ₄ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₃ Cl, Ti (OC ₃ H ₇ ) Cl ₃ , Ti (OC ₃ H ₇ ) ₂ Cl ₂ , Ti (OC ₃ H ₇ ) ₃ Cl, Ti (OC ₄ H ₉ ) Cl ₃ , Ti (OC ₄ H ₉ ) ₂ Cl ₂ , Ti (OC ₄ H ₉ ) ₃ are Cl, particularly _{preferably, TiCl 4, Ti (OC 2} H 5) 4, Ti (OC 3 H 7) 4, Ti (OC 4 H 9) 4, Ti (OC 2 H 5) 3 Cl, _{Ti (OC 3 H 7) 3} Cl, Ti (OC 4 H 9) 3 A l.

As the metallocene catalyst, examples of polymerization catalysts suitable for the multistage polymerization of the component (B) and the component (C) include metallocene catalysts (for example, “metallocene catalysts” which are olefin polymerization catalysts comprising a metallocene transition metal compound and a promoter component. Next-generation polymer industrialization technology (up / down volume; published by InterResearch, Inc., 1994)) is relatively inexpensive, highly active, excellent in polymerization process, and has a narrow molecular weight distribution and copolymer composition distribution. It is used because an ethylene polymer is obtained.
Among them, a catalyst system for olefin polymerization comprising a so-called metallocene complex and an alumoxane as described in JP-A-60-35007, JP-A-8-34809, JP-A-8-127613, etc. A catalyst system using a promoter component other than alumoxane as described in JP-A-11-193306, JP-A-2002-515522, and the like is preferably used. As the metallocene complex, Ti, Zr, and Hf whose central metal is Group 4 of the periodic table are preferably used because they exhibit high activity for ethylene polymerization. Various structures of these ligands of the central metal are currently known, and the polymerization performance such as the molecular weight of the produced polyethylene and the α-olefin copolymerizability is investigated.
As described above, the polyethylene component (B) used in the present invention is preferably one having no long-chain branched structure or containing only a small amount, as mentioned above. The ring structure ligand is preferably a so-called non-crosslinked complex that is not crosslinked with another ligand by a crosslinking group. For example, the following general formula [1] as disclosed in JP-A-11-310612 , [2], [3] or [4], the compound [1] and the compound [3] are preferable, and the compound [1] is more preferable. However, it is said that the higher the concentration of ethylene or α-olefin in the polymerization field and the shorter the polymerization reaction time, the more disadvantageous for the generation of the long chain branched structure. Needless to say, these are limited to relative ones assuming that they are implemented under the same conditions. Further, metallocene complexes described in JP-A-5-132518, JP-A-2000-154196, JP-A-2004-161760 and the like are also preferably used, and for example, described in JP-T-2002-535339. A metallocene complex having a monocyclic or polycyclic heteroaromatic group containing a heteroatom as a substituent on a conjugated five-membered ring structure ligand is also preferably used.

Wherein A ^{1 to} A ⁴ are ligands having a conjugated five-membered ring structure (A ^{1 to} A ⁴ may be the same or different in the same compound), and Q ¹ is two conjugated five-membered members. A bonding group that bridges the ring ligand at an arbitrary position, Z ¹ and Z ² are a ligand containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom, or a sulfur atom bonded to M, a hydrogen atom , A halogen atom or a hydrocarbon group, Q ² is a bonding group that bridges Z ² with any position of the conjugated five-membered ring ligand, M is a metal atom selected from Group 4 of the periodic table, and X And Y represents a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a phosphorus-containing hydrocarbon group or a silicon-containing hydrocarbon group bonded to M, respectively. The above detailed definition shall be in accordance with the publication. ]

In the present invention, as an example of a suitable metallocene complexes, for reasons that it is possible to produce high molecular weight and and molecular weight distribution and the copolymer composition narrow ethylene polymer with high polymerization activity of distribution, the above-mentioned A ¹ ~ A ligand having a conjugated five-membered ring structure represented as A ⁴ , that is, at least one of the five H atoms on the cyclopentadienyl ring ligand is halogen, a hydrocarbon group having 1 to 20 carbon atoms, 1 to 18 carbon-containing silicon-containing hydrocarbon group containing 1 to 6 silicon, 1 to 20 halogenated hydrocarbon group or 1 to 20 hydrocarbon-substituted silyl group, 1 carbon containing oxygen -20 hydrocarbon group (including an alkoxy group directly bonded to the ring by an oxygen atom, etc., sulfur, nitrogen and phosphorus are also the same hereinafter), a C 1-20 hydrocarbon group containing sulfur, and a carbon containing nitrogen Number 1 0 hydrocarbon group include metallocene complex, characterized in that it is substituted by a substituent selected from a hydrocarbon group having 1 to 20 carbon atoms containing phosphorus. The substituents on these cyclopentadienyl rings may form a ring together with the carbon atoms of the cyclopentadienyl ring to which they are bonded, in which case A ^{1 to} A ⁴ are an indenyl ring, an azulenyl ring, It can be a ligand having a secondary ring represented by a benzoindenyl ring, a fluorenyl ring, etc., and is more preferable in that a higher molecular weight ethylene polymer can be obtained.

  As the production process, the component (B) and the component (C) can be produced by a production process such as a gas phase polymerization method, a solution polymerization method, and a slurry polymerization method, and are compared as in the polyethylene resin composition of the present invention. A gas phase polymerization method or a slurry polymerization method is desirable in terms of excellent productivity since the viscosity of the reaction system does not increase even when polyethylene having a low HLMFR, that is, a high molecular weight is produced. Among the polymerization conditions for the ethylene polymer, the polymerization temperature can be selected from the range of 0 to 300 ° C. In the case of gas phase polymerization, the polymerization is performed at a temperature lower than the melting point of the produced polymer. The polymerization pressure can be selected from the range of atmospheric pressure to about 4 MPa. It can be produced by conducting vapor phase polymerization of ethylene and α-olefin in the absence of a solvent in a state where oxygen, water and the like are substantially cut off. An inert hydrocarbon having a relatively low boiling point such as propane, butane, pentane, and hexane may coexist as long as the flow of the polymer powder in the reactor is not hindered.

The hydrogen supplied to the polymerization vessel in the slurry polymerization is consumed as a chain transfer agent, determines the average molecular weight of the produced ethylene-based polymer, and partly dissolves in a solvent and is discharged from the polymerization vessel. The solubility of hydrogen in the solvent is small, and the hydrogen concentration near the polymerization active point of the catalyst is low unless a large amount of gas phase is present in the polymerization vessel. Therefore, if the hydrogen supply amount is changed, the hydrogen concentration at the polymerization active point of the catalyst changes rapidly, and the molecular weight of the produced ethylene polymer changes following the hydrogen supply amount in a short time. Therefore, a more homogeneous product can be produced by changing the hydrogen supply rate in a short cycle. For these reasons, it is preferable to employ a slurry polymerization method as the polymerization method. In addition, the aspect of changing the hydrogen supply amount is preferably changed discontinuously rather than continuously because the effect of broadening the molecular weight distribution can be obtained.
In the component (B) and the component (C) used in the present invention, as described above, it is important to change the hydrogen supply amount, but other polymerization conditions such as polymerization temperature, catalyst supply amount, ethylene, etc. It is also important to change the supply amount of olefin, the supply amount of a comonomer such as 1-hexene, the supply amount of a solvent, etc., at the same time as the change of hydrogen or separately.

As for the suitable manufacturing method of the polyethylene resin composition of this invention, it is preferable that the process of superposing | polymerizing a component (B) and the process of polymerizing a component (C) satisfy the following conditions (J) and conditions (K).
Condition (J): In the step of polymerizing component (B), the molar ratio of hydrogen to ethylene in the gas phase part in the polymerization reactor (H ₂ / C _{2 [gas phase part B]} ) is 0.00-0. .40.
Condition (K): average molar ratio of hydrogen and ethylene in the gas phase in the polymerization reactor in the step of polymerizing component (B) (H ₂ / C _{2 [gas phase B average]} ), and component (C) The ratio of the average molar ratio of hydrogen to ethylene (H ₂ / C _{2 [gas phase C average]} ) ([H ₂ / C _{2 [gas phase C average} ) in the polymerization reactor in the step of polymerizing _] / [H ₂ / C _{2 [vapor phase B average]} ]) is 0.90 to 10.0.
_{[H 2} / _C 2 _{[gas phase C Average]] / [H 2 / C} 2 [ _{gas phase average B]]} is more preferably from 1.10 to 7.0, more preferably 1.10 to 6 .0. At this time, H ₂ / C _{2 [gas phase average]} refers to an average value of measured values at the initial 10 minutes and at the end of each polymerization step. Difference in molecular weight between component (B) and component (C) because [H ₂ / C _{2 [gas phase part C average]} ] / [H ₂ / C _{2 [gas phase part B average]} ] is 0.90 or more. Is not too small, and the compatibility improving effect with the material to be modified is likely to be exhibited, which is preferable. Further, since [H ₂ / C _{2 [gas phase part C average]} ] / [H ₂ / C _{2 [gas phase part B average]} ] is 10.0 or less, component (B) and component (C) The difference in molecular weight does not become excessively large, the dispersion of the component (B) does not become insufficient, and the compatibility improving effect with the material to be modified is easily exhibited, which is preferable. In the case of slurry polymerization using a polymerization liquid-filled loop reactor, which will be described later, there may be a case where the gas phase portion does not exist in the polymerization reactor, but usually a method for measuring the gas composition obtained by vaporizing the reaction liquid is employed. Therefore, it goes without saying that the definition of H ₂ / C _{2 [gas phase part]} in the present invention can be applied as it is.

As a method for producing the polyethylene resin composition of the present invention, a case where the step of polymerizing the component (B) and the step of polymerizing the component (C) satisfy the following conditions (L) and (M) is a suitable method. It can also be mentioned.
Condition (L): Ethylene homopolymerization or ethylene / α-olefin copolymerization is carried out using an olefin polymerization catalyst containing the following components (a), (b) and (c).
Component (a): 1 to 18 carbon atoms in which at least one of the 5 H atoms on the cyclopentadienyl ligand contains halogen, a hydrocarbon group having 1 to 20 carbon atoms, or 1 to 6 silicon atoms. A silicon-containing hydrocarbon group, a halogenated hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon-substituted silyl group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms containing oxygen (directly bonded with an oxygen atom) Including an alkoxy group bonded to a ring, etc. Hereinafter, sulfur, nitrogen and phosphorus are also included), a hydrocarbon group having 1 to 20 carbon atoms containing sulfur, a hydrocarbon group having 1 to 20 carbon atoms containing nitrogen and phosphorus. Ti, Zr or Hf metallocene compound having a structure substituted with a group selected from hydrocarbon groups having 1 to 20 carbon atoms Component (b): reacting with the metallocene compound of component (a) to form a cationic metallocene compound Compound to be generated Minute (c): Fine particle carrier Condition (M): Mass ratio of the produced ethylene polymer and the olefin polymerization catalyst described in the above condition (L) (ethylene polymer mass (g) / olefin polymerization) The mass (g) of the catalyst for use is 3000-50000.

Here, the component (a) refers to the metallocene compound described above, and more preferably on the ligand having a conjugated five-membered ring structure represented by the above-mentioned A ^{1 to} A ⁴ , that is, on the cyclopentadienyl ring ligand. At least 2 or more, more preferably 3 or more, and particularly preferably 4 or more of the five H atoms in the above group are halogen, a hydrocarbon group having 1 to 20 carbon atoms, or a carbon number containing 1 to 6 silicon atoms. 1-18 silicon-containing hydrocarbon group, C1-C20 halogenated hydrocarbon group or C1-C20 hydrocarbon group-substituted silyl group, C1-C20 hydrocarbon group containing oxygen (oxygen atom In addition, an alkoxy group directly bonded to the ring is also included.Sulfur, nitrogen and phosphorus are also the same), a hydrocarbon group having 1 to 20 carbon atoms containing sulfur, a hydrocarbon group having 1 to 20 carbon atoms containing nitrogen, C1-C20 hydrocarbon containing phosphorus A substituent selected from a group, more preferably a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, and a halogenated carbonization having 1 to 20 carbon atoms. A hydrogen group or a C1-C20 hydrocarbon group-substituted silyl group, a C1-C20 hydrocarbon group containing oxygen, a C1-C20 hydrocarbon group containing sulfur, more preferably a C1-C20 20 hydrocarbon group, silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, hydrocarbon group having 1 to 20 carbon atoms including oxygen, particularly preferably hydrocarbon having 1 to 20 carbon atoms It is substituted with a group, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms containing 1 to 6 silicon atoms, or a hydrocarbon group having 1 to 20 carbon atoms containing oxygen.

The substituents on these cyclopentadienyl rings may form a ring together with the carbon atoms of the cyclopentadienyl ring to which they are bonded, in which case A ^{1 to} A ⁴ are an indenyl ring, an azulenyl ring, It is possible to be a ligand having a secondary ring typified by a benzoindenyl ring, a fluorenyl ring and the like, and is more preferable in that a higher molecular weight ethylene polymer can be obtained, and an indenyl ring is further preferable. When the ring is an indenyl ring, a compound represented by the above general formula [2], that is, a bridged bisindenyl complex structure is preferable, and the two indenyl rings are a known carbon bridge group or Si bridge group at the 1-position. A crosslinked structure is more preferable, and in addition, the above-described halogen at the 2-position, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, C1-C20 halogenated hydrocarbon group or C1-C20 hydrocarbon group-substituted silyl group, C1-C20 hydrocarbon group containing oxygen (an alkoxy group bonded directly to the ring with an oxygen atom, etc.) Hereinafter, sulfur, nitrogen and phosphorus are also the same), a hydrocarbon group having 1 to 20 carbon atoms containing sulfur, a hydrocarbon group having 1 to 20 carbon atoms containing nitrogen, and a carbon group having 1 to 20 carbon atoms containing phosphorus. With substituents selected from hydrogen groups A compound is more preferable, and in addition, the above-described halogen at the 4-position, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, 20 halogenated hydrocarbon groups or hydrocarbon group-substituted silyl groups having 1 to 20 carbon atoms, hydrocarbon groups having 1 to 20 carbon atoms including oxygen (including alkoxy groups directly bonded to the ring by oxygen atoms, etc.) , Sulfur, nitrogen and phosphorus as well), a hydrocarbon group having 1 to 20 carbon atoms including sulfur, a hydrocarbon group having 1 to 20 carbon atoms including nitrogen, and a hydrocarbon group having 1 to 20 carbon atoms including phosphorus. Are particularly preferred, and the substituents at the 2-position and 4-position are hydrocarbon groups having 1 to 20 carbon atoms and silicon-containing hydrocarbon groups having 1 to 18 carbon atoms including 1 to 6 silicon atoms. , Selected from oxygen-containing hydrocarbon groups having 1 to 20 carbon atoms Compounds having a substituent that is most preferred.

  Regarding the component (b) and the component (c), together with the method for producing an olefin polymerization catalyst, a method described in JP2011-137146A (paragraphs [0044] to [0069]) and other known techniques are used. Is applicable.

  As a suitable production method for the polyethylene resin composition of the present invention to exhibit its modification performance, it is desired that the amount of ethylene polymer produced per olefin polymerization catalyst is sufficiently high. A more preferable range of the mass ratio (ethylene polymer mass (g) / mass of olefin polymerization catalyst (g)) is 5000 to 30000, and a more preferable range is 7000 to 25000. If the mass ratio is lower than 3000, the catalyst itself may cause a poor appearance or prevent mixing of the component (B), which is not preferable. On the other hand, if the mass ratio is higher than 50,000, it is difficult to control the production ratio of the component (B) and the component (C), or the mixing of the component (B) and the component (C) is unfavorable. .

  Component (B) and component (C) can be composed of a plurality of components. Component (B) and component (C) may be a polymer continuously polymerized in a multistage polymerization reactor using one type of catalyst, and are produced in a multistage polymerization reactor using a plurality of types of catalysts. It may be a polymer.

The component (B) and the component (C) are preferably used in a so-called multistage polymerization method in which polymerization is continuously performed in a plurality of reactors connected in series. However, continuous multi-stage polymerization is preferred for reasons of stability of the catalyst used and sustained activity. And after the process of polymerizing component (B), it is a manufacturing method which transfers the reaction system containing component (B) to the reaction conditions of component (C) as it is and performs the process of polymerizing component (C). In terms of preventing catalyst poisoning and preventing diffusion of solvents and raw materials, it is more preferable.
In addition, the component (B) and / or the component (C) is a polyethylene resin containing the component (B) with a higher molecular weight component so that the polyethylene resin composition of the present invention exhibits better resin modification performance. In order to increase the melt fluidity while maintaining the excellent resin modification performance of the polyethylene resin composition of the present invention for the purpose of designing as a polyethylene, the component (C) is a polyethylene containing a lower molecular weight component. For the purpose of designing as a resin, it can be obtained by multistage polymerization of two or more stages.
A specific preferable polymerization method is the following method. That is, a metallocene catalyst and two reactors are used, ethylene and α-olefin are introduced into the first-stage reactor, and a low-density polymer having a high molecular weight component is produced. In this method, the polymer extracted from the vessel is transferred to the second-stage reactor, and ethylene and hydrogen are introduced into the second-stage reactor to produce a high-density, low-molecular-weight polymer. .
In the case of multistage polymerization, the amount of ethylene-based polymer produced in the second and subsequent polymerization zones and its properties are determined by determining the amount of polymer produced in each stage (which can be determined by analysis of unreacted gas, etc.) The physical properties of the polymer extracted after each stage can be measured, and the physical properties of the polymer produced at each stage can be determined based on the additivity.

<Reformer for resin>
The polyethylene component (A) used in the present invention is an ethylene polymer that is excellent in compatibility with the material to be modified, highly disperses the high molecular weight component, and enhances the physical properties of the molded product without impairing the appearance. Can be suitably used as a resin modifier. Polyethylene component (A) is a resin modifier and has flow characteristics, extrudability, thickness uniformity during blow molding, drawdown properties, etc., moldability, impact strength, rigidity, and other mechanical strength. In addition, it can be used for the purpose of expressing the smoothness of the appearance.
When it is used as a resin modifier, an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, an antifogging agent, an antiblocking agent, a processing aid, a coloring content, a crosslinking agent, a foaming agent, Components such as ordinary additives such as inorganic or organic fillers and flame retardants can be added.
The resin modifier of the present invention can be applied to various resins such as other olefin polymers and rubbers. Among them, the resin modifier is preferably applied to ethylene-based polymers. In the present invention, the following explanation will be given. It is necessary to apply to the specific polyethylene components (D) and (E) to form the polyethylene resin composition of the present invention.

<Polyethylene component (D)>
The polyethylene component (D) used in the polyethylene resin composition of the present invention is a polyethylene that satisfies the following characteristics (d1) to (d3).
Characteristic (d1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 2 g / 10 min or more and 20 g / 10 min or less.
Characteristic (d2): Density is 0.945 g / cm ³ or more and 0.965 g / cm ³ or less.
Characteristic (d3): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed.
The polyethylene component (D) used in the present invention is preferably produced with a chromium catalyst. As the chromium catalyst, a catalyst in which a chromium compound is supported on an inorganic oxide support and at least a part of chromium element is hexavalent is used. The detailed description of the chromium catalyst is as described in publicly known documents including, for example, Japanese Patent Application Laid-Open No. 2011-190437.

Characteristic (d1)
The high load melt flow rate (HLMFR) of the polyethylene component (D) used in the present invention is 2 to 20 g / 10 min. Preferably it is 3-10 g / 10min, More preferably, it is 4-7 g / 10min. An HLMFR of 2 g / 10 min or more is preferable because the fluidity is improved and desired extrusion characteristics can be obtained. On the other hand, it is preferable that HLMFR is 20 g / 10 min or less because desired durability can be obtained.
The HLMFR of the polyethylene component (D) can be adjusted mainly by the amount of hydrogen during the production of the component (D).

Characteristic (d2)
The density of the polyethylene component (D) used in the present invention needs to be 0.945 to 0.965 g / cm ³ , and preferably 0.950 to 0.960 g / cm ³ . It is preferable that the density is 0.945 g / cm ³ or more because desired rigidity can be obtained. On the other hand, it is preferable that the density is 0.965 g / cm ³ or less because desired durability can be obtained.
The density of the polyethylene component (D) can be controlled mainly by changing the α-olefin content of the component (D), and the α-olefin content is a polymerization reaction during the production of the component (D). It can be controlled by changing the ratio of the amount of α-olefin and the amount of ethylene in the vessel.

Characteristic (d3)
The polyethylene component (D) has an elongation viscosity η (t) (unit: Pa · second) and an elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second). In the log-log plot, an inflection point of elongational viscosity due to strain hardening is observed, and the strain hardening degree (λmax) is usually preferably from 1.05 to 5.00.
In addition, it is preferable that the polyethylene component (D) used for this invention has a long chain branched structure. When the polyethylene component (D) has a long chain branched structure, in the polyethylene resin composition of the present invention, it becomes easy to observe the inflection point of the extensional viscosity due to strain hardening. By observing the inflection point, in the polyethylene resin composition, there is an effect that the crystallization rate can be extremely effectively increased and the molding cycle is improved.
In the present specification, the presence or absence of an inflection point of elongational viscosity due to strain hardening can be observed in the measurement of the strain hardening degree.
Regarding the method for measuring the strain hardening degree, the same value can be obtained in principle by any method as long as the uniaxial elongation viscosity can be measured. Details are described.

In the measurement of polyethylene according to the present invention, preferable measurement methods and measuring instruments include the following.
Measuring method:
・ Device: Ares manufactured by Rheometrics
-Jig: EXTENSIONAL VISUALITY FIXTURE, manufactured by TA Instruments
・ Measurement temperature: 170 ℃
-Strain rate: 0.1 / second-Preparation of test piece: Press-molded to produce a sheet of 18 mm x 10 mm and a thickness of 0.7 mm.

The inflection point of elongation viscosity and strain hardening degree (λmax) resulting from strain hardening can be obtained as follows.
Calculation method:
The elongational viscosity at 170 ° C. and a strain rate of 0.1 / second is plotted as a log-log graph of time t (second) on the horizontal axis and elongation viscosity η (Pa · second) on the vertical axis. On the log-log graph, the maximum elongation viscosity until strain becomes 4.0 after strain hardening is η _Max (t1) (t1 is the time when the maximum elongation viscosity is shown), and the extension viscosity before strain hardening. when the approximate line and η _linear (t), defines the value calculated as _{η Max (t1) / η linear} (t1) strain hardening degree and (.lambda.max). The presence / absence of strain hardening is determined by whether or not there is an inflection point at which the extensional viscosity changes from an upward convex curve to a downward convex curve over time.

1 and 2 are typical plots of elongational viscosity. FIG. 1 shows a case where an inflection point of elongational viscosity is observed, and η _Max (t1) and η _Linear (t1) are shown in the figure. FIG. 2 shows a case where an inflection point of elongational viscosity is not observed.

Moreover, it is preferable that a polyethylene component (D) satisfies the following characteristic (d4).
Characteristic (d4): Molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is more than 7 and 50 or less, preferably more than 7 and 40 or less, more preferably more than 7 and 30 or less. is there.
The molecular weight distribution (Mw / Mn) measured by GPC is related to improvements in various physical properties and moldability of the polymer, and is also related to improvements in the appearance of the molded product.
When the molecular weight distribution (Mw / Mn) of the polyethylene component (D) used in the present invention is within the above range, more excellent hollow molding processability can be exhibited. Further, when the molecular weight distribution (Mw / Mn) exceeds 7, the viscosity of the polyethylene component (D) in the low strain rate region becomes high, and the viscosity of the final resin composition in the low strain rate region can be increased. The compatibility with the polyethylene component (A) is improved and the product appearance is excellent. The resin pressure at the time of extrusion is appropriate, making it difficult to cause fluid instability such as sharkskin, resulting in poor appearance. It is preferable from the viewpoint of easy suppression. On the other hand, when the molecular weight distribution (Mw / Mn) is 50 or less, it is easy to suppress deterioration of the pinch-off shape of the molded product, and the impact strength as a hollow molded product is easily improved.
The molecular weight distribution within a predetermined range can be achieved by employing a catalyst capable of controlling the molecular weight distribution and appropriate polymerization conditions. In the case of a bimodal or multimodal polymer, it can be controlled by adjusting the molecular weight of each component.

The molecular weight (weight average molecular weight Mw, number average molecular weight Mn) and molecular weight distribution measured by gel permeation chromatography (GPC) can be measured under the following conditions.
[Measurement condition]
Model used: Alliance GPCV2000 manufactured by Japan Waters Co., Ltd. Measurement temperature: 145 ° C
Solvent: orthodichlorobenzene (ODCB)
Column: Showex Denko Shodex HT-806M x 2 + HT-G
Flow rate: 1.0 mL / min Injection rate: 0.3 mL

[Preparation of sample]
A 3 mL sample and 3 mL of orthodichlorobenzene (containing 0.1 mg / mL 1,2,4-trimethylphenol) were weighed into a 4 mL vial, and capped with a resin screw cap and a Teflon (registered trademark) septum. Then, it melt | dissolves for 2 hours using the SSC-9300 type | mold high temperature shaker by Senshu Scientific which set the temperature to 150 degreeC. After completion of dissolution, it is visually confirmed that there are no insoluble components.
[Create calibration curve]
Four 4 mL glass bottles are prepared, and 0.2 mg each of monodisperse polystyrene standard samples or n-alkanes of the combinations (1) to (4) below are weighed, followed by orthodichlorobenzene (0.1 mg / mL). SSC-9300 type manufactured by Senshu Kagaku Co., Ltd., which was set at a temperature of 150 ° C. after weighing 3 mL of (including 1,2,4-trimethylphenol) and capping with a resin screw cap and a Teflon (registered trademark) septum. Dissolve for 2 hours using a high temperature shaker.
(1) Shodex S-1460, S-66.0, n-eicosane (2) Shodex S-1950, S-152, n-tetracontane (3) Shodex S-3900, S-565, S -5.05
(4) Shodex S-7500, S-1010, S-28.5
The vial containing the sample solution is set in the apparatus, the measurement is performed under the above-mentioned conditions, and the chromatogram (retention time and differential refractometer detector response data set) is recorded at a sampling interval of 1 second. From the obtained chromatogram, the retention time (peak apex) of each polystyrene standard sample is read and plotted against the logarithmic value of the molecular weight. Here, the molecular weights of n-eicosane and n-tetracontane are 600 and 1200, respectively. A nonlinear least square method is applied to this plot, and the obtained quartic curve is used as a calibration curve.

[Calculation of molecular weight]
Measure under the above conditions and record the chromatogram at a sampling interval of 1 second.
From this chromatogram, Sadao Mori “Size Exclusion Chromatography” (Kyoritsu Shuppan), Chapter 4, p. The differential molecular weight distribution curve and average molecular weight values (Mn, Mw, and Mz) are calculated by the method described in 51-60. However, in order to correct the molecular weight dependency of dn / dc, the height H from the baseline in the chromatogram is corrected by the following equation. Chromatogram recording (data acquisition) and average molecular weight calculation are performed using an in-house program (created with Microsoft Visual Basic 6.0 from Microsoft) on a PC in which Microsoft Windows (registered trademark) XP is installed.
H ′ = H / [1.032 + 189.2 / M (PE)]
In addition, the following formula is used for molecular weight conversion from polystyrene to polyethylene.
M (PE) = 0.468 × M (PS)

<Method for producing polyethylene component (D)>
The polyethylene component (D) is a homopolymer of ethylene or ethylene and an α-olefin having 3 to 12 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1- Obtained by copolymerization with octene or the like. Also, copolymerization with a diene for the purpose of modification is possible. Examples of the diene compound used at this time include butadiene, 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene, and the like.
The comonomer content in the polymerization of the polyethylene component (D) can be arbitrarily selected. For example, the α-olefin content in the ethylene polymer is 0 to 20 mol%, preferably 0. -10 mol%.

  As described above, a chromium catalyst is used as the polymerization catalyst for the polyethylene component (D).

  As a production process, the polyethylene component (D) can be produced by a production process such as a gas phase polymerization method, a solution polymerization method, or a slurry polymerization method, and among these, a gas phase polymerization method or a slurry polymerization method is desirable. Among the polymerization conditions for the ethylene polymer, the polymerization temperature can be selected from the range of 0 to 300 ° C. In slurry polymerization, polymerization is performed at a temperature lower than the melting point of the produced polymer. The polymerization pressure can be selected from the range of atmospheric pressure to about 10 MPa. It is selected from aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, etc. in a state where oxygen and water are substantially cut off. It can be produced by slurry polymerization of ethylene and α-olefin in the presence of an inert hydrocarbon solvent.

The hydrogen supplied to the polymerization vessel in the slurry polymerization is consumed as a chain transfer agent, determines the average molecular weight of the polyethylene component (ethylene polymer) produced, and partly dissolves in the solvent and is discharged from the polymerization vessel. The The solubility of hydrogen in the solvent is small, and the hydrogen concentration near the polymerization active point of the catalyst is low unless a large amount of gas phase is present in the polymerization vessel. Therefore, if the hydrogen supply amount is changed, the hydrogen concentration at the polymerization active point of the catalyst changes rapidly, and the molecular weight of the polyethylene component to be generated changes following the hydrogen supply amount in a short time. Therefore, a more homogeneous product can be produced by changing the hydrogen supply rate in a short cycle. For these reasons, it is preferable to employ a slurry polymerization method as the polymerization method. In addition, the aspect of changing the hydrogen supply amount is preferably changed discontinuously rather than continuously because the effect of broadening the molecular weight distribution can be obtained.
In the polyethylene component (D) used in the present invention, as described above, it is important to change the hydrogen supply amount, but other polymerization conditions such as the polymerization temperature, the catalyst supply amount, and the supply amount of olefins such as ethylene. It is also important to change the supply amount of a comonomer such as 1-hexene, the supply amount of a solvent, and the like, simultaneously with hydrogen change or separately.

  The polyethylene component (D) can be composed of a plurality of components. The polyethylene component (D) may be a polymer successively polymerized in a multistage polymerization reactor using one type of catalyst, or a polymer produced in a multistage polymerization reactor using a plurality of types of catalysts. But you can.

A specific preferable polymerization method of the polyethylene component (D) is the following method. That is, this is a method for producing a polymer by using a chromium catalyst and a single tank or a multi-tank reactor and introducing ethylene and α-olefin into the reactor.
In the case of multistage polymerization, the amount of ethylene-based polymer produced in the second and subsequent polymerization zones and its properties are determined by determining the amount of polymer produced in each stage (which can be determined by analysis of unreacted gas, etc.) The physical properties of the polymer extracted after each stage can be measured, and the physical properties of the polymer produced at each stage can be determined based on the additivity.

<Polyethylene component (E)>
The polyethylene component (E) used in the polyethylene resin composition of the present invention is a polyethylene that satisfies the following characteristics (e1) to (e2).
Characteristic (e1): Melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg is 10 g / 10 min or more and 200 g / 10 min or less.
Characteristics (e2): density of 0.960 g / cm ³ or more 0.980 g / cm ³ or less.
The polyethylene component (E) of the present invention is produced by a metallocene catalyst or a Ziegler catalyst. As a metallocene catalyst or a Ziegler catalyst, it is as having mentioned above, The thing similar to what is used for manufacture of a polyethylene component (A) can be used.
The polyethylene component (E) is a polyethylene produced by a metallocene catalyst, and the molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is usually 2 to 25, and produced by a Ziegler catalyst. As the polyethylene, the molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is usually 6 to 25, and the polyethylene produced by the metallocene catalyst and the polyethylene produced by the Ziegler catalyst are In both logarithmic plots of elongational viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at 170 ° C. and elongational strain rate of 0.1 (unit: 1 / second) Polyethylene in which the inflection point of the resulting extensional viscosity is not observed is preferable.

Characteristic (e1):
The melt flow rate (MFR) of the polyethylene component (E) at a temperature of 190 ° C. and a load of 2.16 kg is 10 g / 10 min or more and 200 g / 10 min. Preferably it is 10-100 g / 10min, More preferably, it is 10-30 g / 10min. An MFR of 10 g / 10 min or more is preferable because fluidity is improved and desired extrusion characteristics can be obtained. On the other hand, when the MFR is 200 g / 10 min or less, the desired durability can be obtained, which is preferable.
In addition, in this specification, MFR of a polyethylene component and a polyethylene resin composition can be measured based on JISK6922-2: 1997.
The MFR of the polyethylene component (E) can be adjusted mainly by the amount of hydrogen during the production of the component (E).

Characteristic (e2):
Density polyethylene component (E) is required to be 0.960~0.980g / cm ^3, preferably 0.960~0.975g / cm ^3, more preferably 0.960~0.970g / Cm ³ . A density of 0.960 g / cm ³ or more is preferable because desired rigidity can be obtained. On the other hand, it is preferable that the density is 0.980 g / cm ³ or less because desired durability can be obtained.
The density of the polyethylene component (E) can be adjusted mainly by the amount of α-olefin at the time of producing the component (E).

<Method for producing polyethylene component (E)>
The polyethylene component (E) is a homopolymer of ethylene or ethylene and an α-olefin having 3 to 12 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1- Obtained by copolymerization with octene or the like. Also, copolymerization with a diene for the purpose of modification is possible. Examples of the diene compound used at this time include butadiene, 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene, and the like.
The comonomer content during the polymerization of the polyethylene component (E) can be arbitrarily selected. For example, the α-olefin content in the polyethylene component (E) is 0 to 40 mol%, preferably It is 0-30 mol%.

  As described above, a metallocene catalyst or a Ziegler catalyst is used as the polymerization catalyst for the polyethylene component (E).

  As a production process, the polyethylene component (E) can be produced by a production process such as a gas phase polymerization method, a solution polymerization method, or a slurry polymerization method, and among these, a gas phase polymerization method or a slurry polymerization method is desirable. Among the polymerization conditions for the polyethylene component (E), the polymerization temperature can be selected from the range of 0 to 300 ° C. In slurry polymerization, polymerization is performed at a temperature lower than the melting point of the produced polymer. The polymerization pressure can be selected from the range of atmospheric pressure to about 10 MPa. It is selected from aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, etc. in a state where oxygen and water are substantially cut off. It can be produced by slurry polymerization of ethylene and α-olefin in the presence of an inert hydrocarbon solvent.

In the slurry polymerization, hydrogen supplied to the polymerization vessel is consumed as a chain transfer agent, determines the average molecular weight of the polyethylene component to be produced, and partly dissolves in a solvent and is discharged from the polymerization vessel. The solubility of hydrogen in the solvent is small, and the hydrogen concentration near the polymerization active point of the catalyst is low unless a large amount of gas phase is present in the polymerization vessel. Therefore, if the hydrogen supply amount is changed, the hydrogen concentration at the polymerization active point of the catalyst changes rapidly, and the molecular weight of the polyethylene component to be generated changes following the hydrogen supply amount in a short time. Therefore, a more homogeneous product can be produced by changing the hydrogen supply rate in a short cycle. For these reasons, it is preferable to employ a slurry polymerization method as the polymerization method. In addition, the aspect of changing the hydrogen supply amount is preferably changed discontinuously rather than continuously because the effect of broadening the molecular weight distribution can be obtained.
In the polyethylene component (E), as described above, it is important to change the hydrogen supply amount, but other polymerization conditions such as polymerization temperature, catalyst supply amount, supply amount of olefins such as ethylene, 1-hexene, etc. It is also important to appropriately change the supply amount of the comonomer, the supply amount of the solvent, etc. simultaneously or separately with the change of hydrogen.

  The polyethylene component (E) can be composed of a plurality of components. The polyethylene component (E) may be a polymer successively polymerized in a multistage polymerization reactor using one type of catalyst, or a polymer produced in a multistage polymerization reactor using a plurality of types of catalysts. But you can.

Another specific preferable polymerization method of the polyethylene component (E) is the following method. That is, a Ziegler catalyst containing a titanium-based transition metal compound and an organoaluminum compound and a single reactor are used, and ethylene, hydrogen and, if necessary, an α-olefin are introduced into the reactor to have a predetermined density and MFR. It is a method for producing a polymer.
In the case of multi-stage polymerization, the amount of polyethylene component produced in the polymerization zone from the second stage onward and its properties are determined by determining the amount of polymer produced at each stage (which can be determined by analysis of unreacted gas). Thereafter, the physical properties of the polymer extracted from each step can be measured, and the physical properties of the polymer produced at each stage can be determined based on the additivity.

<Polyethylene resin composition>
In the polyethylene resin composition of the present invention, the polyethylene component (A) is 10% by mass to 40% by mass, the polyethylene component (D) is 5% by mass to 50% by mass, and the polyethylene component (E) is 40% by mass. % To 85% by mass and satisfy the following characteristics (1) to (5).
Characteristic (1): MFR is 0.1 g / 10 min or more and 1 g / 10 min or less.
Characteristic (2): HLMFR is 10 g / 10 min or more and 50 g / 10 min or less.
Characteristic (3): Melt flow rate ratio (HLMFR / MFR) which is a ratio of HLMFR to MFR is 50 or more and 140 or less.
Characteristics (4): density of 0.940 g / cm ³ or more 0.965 g / cm ³ or less.
Characteristic (5): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed.

  In the polyethylene resin composition of the present invention, the blending ratio of the polyethylene component (A) to the polyethylene components (D) and (E) is 10% by mass or more and 40% by mass or less of the polyethylene component (A). 5% by mass or more and 50% by mass or less, and polyethylene component (E) by 40% by mass or more and 85% by mass or less. Preferably, the polyethylene component (A) is 15% by mass or more and 40% by mass or less, and the polyethylene component (D ) Is 10% by mass or more and 30% by mass or less, and the polyethylene component (E) is 40% by mass or more and 70% by mass or less. More preferably, the polyethylene component (A) is 20% by mass or more and 40% by mass or less. D) is a composition containing 10% by mass to 25% by mass and a polyethylene component (E) of 40% by mass to 70% by mass. When the component (A) is 10% by mass or more, the content of the high molecular weight component in the polyethylene resin composition is improved, and desired impact strength, stress crack resistance, and the like can be obtained. On the other hand, when the component (A) is 40% by mass or less, fluidity is improved and desired extrudability is obtained, which is preferable.

Characteristics (1)
The polyethylene resin composition of the present invention has an MFR of 0.1 g / 10 min or more and 1 g / 10 min or less. The MFR is preferably 0.15 g / 10 min or more and 0.8 g / 10 min or less, more preferably 0.2 g / 10 min or more and 0.6 g / 10 min or less, particularly preferably 0.25 g / 10 min. The range is 0.50 g / 10 min or less.
If the MFR is 0.1 g / 10 min or more, the fluidity is improved, and flow instability phenomena such as sharkskin and melt fracture are less likely to occur, so the appearance of the molded product can be improved. .
On the other hand, when the MFR is 1 g / 10 min or less, impact resistance and environmental stress crack resistance can be achieved, and the drop impact resistance and long-term durability of the molded product are improved.
The MFR of the polyethylene resin composition can be adjusted by the respective hydrogen amounts and temperatures during polymerization of the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E), and the blending amount of each component.
MFR can be measured in the same manner as described above.

Characteristic (2)
The polyethylene resin composition of the present invention has an HLMFR of 10 g / 10 min or more and 50 g / 10 min or less. The HLMFR is preferably in the range of 20 g / 10 min or more and 35 g / 10 min or less, more preferably 25 g / 10 min or more and 30 g / 10 min or less.
If the HLMFR is 10 g / 10 min or more, the fluidity can be improved to reduce the heat generated by the extruder motor during molding and the resin heat generated by shearing, and the fluidity such as sharkskin and melt fracture can be reduced. Since it becomes difficult for a stable phenomenon to occur, the appearance of the molded product can be improved.
On the other hand, when the HLMFR is 50 g / 10 min or less, impact resistance and environmental stress crack resistance can be achieved, and the drop impact resistance and long-term durability of the molded product can be improved.
The HLMFR of the polyethylene resin composition can be adjusted by the respective hydrogen amounts and temperatures during polymerization of the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E), and the blending amount of each component.
HLMFR can be measured in the same manner as described above.

Characteristic (3)
The polyethylene resin composition of the present invention has a melt flow rate ratio (HLMFR / MFR) that is a ratio of HLMFR to MFR of 50 or more and 140 or less. The melt flow rate ratio is preferably in the range of 51 to 130, more preferably 52 to 120.
HLMFR / MFR has a strong correlation with the molecular weight distribution. When HLMFR / MFR takes a large value, the molecular weight distribution becomes wide. When HLMFR / MFR takes a small value, the molecular weight distribution becomes narrow. When HLMFR / MFR is 140 or less, the compatibility of each component is improved, and effects such as improvement in pinch-off moldability and impact resistance are obtained. Further, when HLMFR / MFR is 50 or more, effects such as improvement of melt tension, difficulty in occurrence of flow instability such as shark skin, and improvement of ESCR are obtained.
The control method of HLMFR / MFR can be performed mainly according to the control method of molecular weight distribution.

Characteristic (4)
Polyethylene resin composition of the present invention, density of 0.940 g / cm ³ or more 0.965 g / cm ³ or less. The density is preferably in the range of 0.950 g / cm ³ or more and 0.960 g / cm ³ or less.
If the density is 0.940 g / cm ³ or more, desired rigidity can be obtained. On the other hand, when the density is 0.965 g / cm ³ or less, durability can be improved.
The density can be adjusted mainly by the amount of α-olefin during polymerization of the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E), and can be adjusted by the blending amount of each component. it can.
The density can be measured in the same manner as described above.

Characteristic (5)
The polyethylene resin composition of the present invention has an elongational viscosity η (t) (unit: Pa · second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) and an elongation time t (unit: unit). (Second) logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed.
The presence or absence of an inflection point of elongational viscosity due to strain hardening can be observed in the measurement of the strain hardening degree, and can be measured by the same method as the measurement method of the strain hardening degree of the polyethylene component (D) described above. it can.

Characteristic (6)
It is preferable that the polyethylene resin composition of the present invention further satisfies the following property (6).
Characteristic (6): Fracture time (FNCT) at 80 ° C. and 3.7 MPa by a full notch creep test is 285 hours or more.
The longer the full notch creep test (FNCT), the better the long-term durability such as environmental stress crack resistance. A fracture time (FNCT) of 285 hours or more is preferable from the viewpoint of particularly excellent balance between rigidity (density) and long-term durability such as environmental stress crack resistance. The fracture time (FNCT) is obtained from the following relational expression (1).
log (FNCT) ≧ −257.5 × (density) +247.9 Relational expression (1)
The full notch creep test can be performed according to ISO DIS 16770. A sample is prepared by preparing a test piece having a cross section of 4 mm × 4 mm in which a 1 mm notch is made with a razor blade on the entire circumference of a 6 mm × 6 mm × 11 mm prism. Among them, a tensile stress corresponding to 3.7 MPa is given to the specimen, and the time until the specimen breaks is measured to obtain the FNCT breaking time.
In order for the polyethylene resin composition of the present invention to satisfy the characteristic (6), the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E) having specific physical properties are mixed at a predetermined blending ratio. It is preferable to do.

Characteristic (7)
The polyethylene resin composition of the present invention preferably further satisfies the following property (7).
Characteristic (7): Tensile impact strength is 233 kJ / m ² or more. Preferably it is 250 kJ / m ² or more, more preferably 280 kJ / m ² or more.
The polyethylene resin composition of the present invention preferably has a tensile impact strength of 233 kJ / m ² or more. The tensile impact strength here is measured based on ASTM D1822-68. When the tensile impact strength is 233 kJ / m ² or more, the impact resistance as a container tends to be improved. The tensile impact strength can be adjusted by the density of polyethylene, and the tensile impact strength can be increased by reducing the density. Further, the tensile impact strength can be adjusted by MFR and HLMFR of the polyethylene resin composition, and the tensile impact strength can be increased by lowering MFR and HLMFR.

The polyethylene resin composition of the present invention preferably further satisfies the following property (8) from the viewpoint of hollow moldability such as drawdown resistance.
Characteristic (8): The melt tension (MT) measured at 190 ° C. is 40 mN or more.
The melt tension is more preferably 65 mN or more. Moreover, the melt tension corresponding to HLMFR is high, preferably satisfying the following relational expression (2), and more preferably satisfying the following relational expression (3).
MT> −22.45 × ln (HLMFR) +137.82 Relational expression (2)
MT> −22.45 × ln (HLMFR) +157.82 Relational expression (3)
Here, MT (mN) is the melt tension, and HLMFR (g / 10 min) is the melt flow rate at a temperature of 190 ° C. and a load of 21.6 Kg.
In the present invention, when HLMFR is taken on the horizontal axis, melt tension is taken on the vertical axis, and the example data of the present invention is plotted, the relational expression (2) is an equation for distinguishing the preferred range of the present invention from the prior art. Yes, relational expression (3) is a mathematical expression for defining a more preferable range of the present invention.
The melt tension is determined by measuring the stress when the molten ethylene polymer is stretched at a constant speed, and can be measured under the following conditions.
[Measurement condition]
Model used: Toyo Seiki Seisakusho, Capillograph 1B
Nozzle diameter: 2.095mm
Nozzle length: 8.0mm
Inflow angle: 180 ° (flat)
Extrusion speed: 15 mm / min Take-off speed: 6.5 m / min Measuring temperature: 190 ° C.
In order for the polyethylene resin composition of the present invention to satisfy the characteristic (8), the polyethylene component (A), the polyethylene component (D), and the polyethylene component (E) having specific physical properties are mixed at a predetermined blending ratio. It is preferable.

In addition, the polyethylene component (A), the polyethylene component (D), the polyethylene component (E) or the polyethylene resin composition is an additive that is added to a normal polyolefin as necessary, as long as the object of the present invention is not impaired. It may contain. These additives can be used alone or in combination of two or more.
Examples of the additive include a stabilizer such as a heat stabilizer, a weather stabilizer, a crosslinking agent, a crosslinking aid, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, a lubricant, a dye, a pigment, a filler, Examples include mineral oil softeners, petroleum resins, and waxes.

According to the polyethylene resin composition of the present invention, since it is a polyethylene material having the above characteristics (1) to (4), it is excellent in hollow moldability, environmental stress crack resistance and impact resistance, and is thinner and lighter. It can be molded, has excellent high-speed moldability, can be molded in a high cycle, has good pinch-off characteristics, has high compatibility with resin components, and is particularly suitable for the appearance of the molded body. It is possible to obtain an excellent molded body.
Furthermore, preferably, in addition to the above characteristics (1) to (4), a polyethylene resin composition having one or more of the above characteristics (5) to (8) exhibits the above-described effects better.
Further, by using the specific polyethylene component (A) together with the specific polyethylene component (D) and the component (E), an ethylene polymer composition using a conventional chromium catalyst or a Ziegler catalyst can be obtained. The environmental stress crack resistance can be further improved from the ethylene polymer composition used and the ethylene polymer composition in which they are mixed.

In general, polyethylene is processed into an industrial product by a molding method that passes through a molten state such as film molding, blow molding, foam molding, etc., but at this time, elongation flow characteristics represented by the above-mentioned elongation viscosity and strain hardening degree are used. It is well known that has a great influence on the ease of molding.
That is, polyethylene having a narrow molecular weight distribution and no long chain branching has poor moldability due to low melt strength, whereas polyethylene having an ultrahigh molecular weight component or long chain branching component is strain-hardened (strain Hardening), that is, polyethylene having a characteristic that the extensional viscosity rapidly increases on the high strain side, and it is said that polyethylene exhibiting this characteristic is excellent in moldability. Polyethylene resin having such elongation flow characteristics can prevent, for example, uneven thickness and blow-through of products in film molding and hollow molding, enables high-speed molding, and can increase the closed cell ratio during foam molding. There are benefits, such as improved strength of the molded product, improved design, lighter weight, improved molding cycle, improved heat insulation, etc. The strength anisotropy presumed to be caused by the orientation causes inconveniences such as a reduction in impact strength of the molded product.
On the other hand, according to the present invention, as described above, the polyethylene component (D) and the component (E) satisfying the specific physical property balance are used, and the polyethylene component (A) having specific physical properties is used in the composition. By using it as a low melt flow component, that is, a high molecular weight component of the product, it contributes to improvement in rigidity and environmental stress crack resistance and impact resistance, as well as molding processing characteristics, particularly drawdown resistance and pinch-off moldability. It is also excellent in hollow moldability, can be molded with a thinner and lighter weight, has high melt tension and excellent draw-down resistance, and can be used for complex-shaped hollow molding.

Since the polyethylene component (D) and the component (E) satisfying the specific physical property balance are used, the polyethylene resin composition is excellent in compatibility of each resin component in the resin composition and particularly excellent in the appearance of the molded body. It becomes a thing.
In particular, when the polyethylene component (A) has a long-chain branched structure, the melt flow rate ratio is specific, and thus the polyethylene component (A) is highly dispersed in the polyethylene component (D) and the component (E). Therefore, the compatibility is good. Therefore, in the molded product, the surface properties become smooth and the appearance is particularly excellent.
Since the polyethylene resin composition of the present invention is a polyethylene resin composition having the above physical properties, it is excellent in moldability, high fluidity, odor, food safety, rigidity, heat resistance and the like.

<Method for producing polyethylene resin composition>
There is no restriction | limiting in particular as a manufacturing method of the polyethylene resin composition of this invention, A well-known method is applicable. For example, a polyethylene component (A), a polyethylene component (D), and a polyethylene component (E) are produced individually, and these are usually used in the above proportions, such as an extruder, a Banbury mixer, a roll, a Brabender plastograph, a kneader, etc. It can be produced by melt-kneading using a kneader. The temperature for melting and kneading is not particularly limited as long as the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E) are melted, but it is usually produced by kneading in the range of 180 to 350 ° C. it can. Among these kneaders, a single-screw or twin-screw extruder or a continuous kneader can be used, and it is particularly preferable to produce using a twin-screw extruder. After being pelletized by typical melt mixing, it can be molded by various molding machines to obtain a desired molded product.

Since the polyethylene resin composition of the present invention produces a molded product, other olefinic polymers contained in a molded product made of a normal polyolefin, if necessary, within a range that does not impair the object of the present invention, In addition to rubber, etc., antioxidants (phenolic, phosphorus, sulfur), UV absorbers, light stabilizers, lubricants, antistatic agents, antifogging agents, antiblocking agents, processing aids, coloring pigments, pearl pigments One or more known additives such as a polarizing pearl pigment, a crosslinking agent, a foaming agent, a neutralizing agent, a thermal stabilizer, a crystal nucleating agent, an inorganic or organic filler, and a flame retardant can be blended.
Examples of the organic filler include carbon fiber, carbon black, and carbon nanotube. Examples of the inorganic filler include silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon, water. Aluminum oxide, magnesium hydroxide, dolomite, calcium sulfate, potassium titanate, barium sulfate, talc, clay, mica, glass flake, glass beads, glass fiber, aluminum silicate, calcium silicate, montmorillonite, bentonite, molybdenum sulfide, graphite Etc.
As the filler, calcium carbonate, talc, metal powder (aluminum, copper, iron, lead, etc.), silica, diatomaceous earth, alumina, gypsum, mica, clay, asbestos, graphite, carbon black, titanium oxide, etc. can be used. .
In any case, various additives may be blended with the polyethylene resin as necessary, and the mixture may be kneaded with a kneading extruder, a Banbury mixer, or the like to obtain a molding material.

2. A molded object and a container The molded object of this invention is a molded object created using the polyethylene resin composition which concerns on the said this invention.
Moreover, the container of this invention is a container created using the polyethylene resin composition which concerns on the said this invention.
The polyethylene resin composition of the present invention can be obtained by molding by a known molding method.
Using the polyethylene resin composition of the present invention as a raw material, a molded product can be produced by various molding methods. Preferably, it is mainly molded by a hollow molding method or the like, and various molded products such as a hollow container are preferably obtained.

  The polyethylene resin composition of the present invention is suitable for uses such as containers that require such characteristics, and in particular, cosmetic containers, detergents, shampoos and rinse containers, or edible oils that are required to have good appearance. It can use suitably for uses, such as a container for foodstuffs.

  In particular, a container which is a molded body using the polyethylene resin composition of the present invention can be molded at a high speed and can be cycled, has excellent product characteristics, and is economically advantageous, such as detergents, shampoos and rinses. It is suitable as a container.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

1. Measurement method The measurement methods used in the examples are as follows.
(1) Melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg:
Measured according to JIS K6922-2: 1997.
(2) Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 kg:
Measured according to JIS K6922-2: 1997.
In addition, the HLMFR of the component (B) or the component (C) was obtained by correlating the hydrogen concentration during the production of the polyethylene polymer with the HLMFR of the polyethylene polymer in the case of a small amount of batch polymerization.
When polymerizing in large quantities, the polyethylene polymer was extracted from the reaction vessel of the first reaction step, and the HLMFR of the polyethylene polymer of component (B) was measured. Subsequently, the polyethylene polymer is extracted from the reaction vessel of the second reaction step, the HLMFR of the polyethylene polymer of component (A) is measured, and the weight percentage is between the HLMFR after the second reaction step and the HLMFR after the first reaction step. We demanded that additivity about
(3) Density:
It measured based on JIS K6922-1,2: 1997.
In addition, the density of the component (B) or the component (C) was determined by correlating the α-olefin concentration during the production of the polyethylene polymer with the density of the polyethylene polymer in the case of a small amount of batch polymerization.
When polymerizing in large quantities, the polyethylene polymer was extracted from the reaction vessel of the first reaction step, and the density of the polyethylene polymer of component (B) was measured. Next, the polyethylene polymer is withdrawn from the reaction vessel of the second reaction step, the density of the polyethylene polymer of the polyethylene resin composition is measured, and mass% between the density after the second reaction step and the density after the first reaction step. We demanded that additivity about

(4) Content ratio of polyethylene component (B) In the production process of polyethylene component (A) described later, polyethylene is determined from the ratio of the amount of ethylene and comonomer as raw materials consumed in the first stage reactor and the second stage reactor. The content ratio of the polyethylene component (B) contained in the component (A) was calculated.

(5) Fracture time in full notch creep test (FNCT) (measured at 80 ° C. and 3.7 MPa):
The measurement was performed at 80 ° C. and 3.7 MPa in accordance with the all-around notch tensile creep test of JIS K6774 (1995) Appendix 1. The test piece was cut from a 6 mm thick compression molded sheet prepared under the conditions of JIS K6922-2 (1997) Table 2 and notched all around (test piece thickness 6 mm, notch depth 1 mm, full circumference). It was used. Pure water was used as a test solution for immersing the sample.

(6) Melt tension:
The melt tension (MT) was determined by measuring the stress when the molten ethylene polymer was stretched at a constant speed, and was measured under the following conditions.
[Measurement condition]
Model used: Toyo Seiki Seisakusho, Capillograph 1B
Nozzle diameter: 2.095mm
Nozzle length: 8.0mm
Inflow angle: 180 ° (flat)
Extrusion speed: 15 mm / min Take-off speed: 6.5 m / min Measuring temperature: 190 ° C.

(7) Tensile impact strength (TIS)
A 1.5 mm compression molded sheet was prepared according to JIS K6922-2, and a test piece punched out with an S-type dumbbell was prepared according to ASTM D1822. Impact strength (unit: kJ / m ² ) was measured.

(8) Pinch-off characteristics:
The measurement of tan δ at 150 ° C. and 100 rad / sec measured with a rheometer is performed using a sample adjusted by a hot press, and using a rheometer (Ales manufactured by Rheometrics), the storage elastic modulus G ′ at 150 ° C. and an angular velocity of 100 rad / sec. And loss elastic modulus G ″ were measured, and tan δ (= G ″ / G ′) was calculated. The measurement conditions are described below.
[Measurement condition]
Apparatus: Ales manufactured by Rheometrics
Jig: 25mm diameter parallel plate, plate spacing approx. 1.7mm
Measurement temperature: 150 ° C
Distortion: 10%

(9) Hollow moldability With a single-layer direct blow molding machine (manufactured by BRENS Co., Ltd., screw diameter = φ70 mm, L / D = 24, compression ratio (CR) = 3.0) so as to have a constant pinch-off width. Using a straight die with an arbitrary die core diameter, adjusting the molding resin temperature to about 210 ° C. under the condition of a screw rotation speed of 10 rpm, extruding a parison, and forming a flat container shape of about 400 ml (length: about 19 cm, width: about 7 cm, maximum depth: about A blow mold (a mold having a cavity surface blasting finish and a cavity surface roughness Ra value of 0.7 μm), a mold having a diameter of 5 cm and a container having a screw-shaped mouth portion having an outer diameter of about 2 cm and a height of about 2 cm. Blow molding was performed at a mold temperature of 20 ° C., a blow pressure of 6 kg / cm 2, a container mass of about 30 g, and a molding cycle of approximately 10 to 12 seconds. A container with the above conditions can be molded with a hollow moldability of “Good (○)”, and a molded product with a uniform wall thickness distribution can be obtained by making a hole in the fusion interface during blow-up or by drawing down significantly. What was difficult was defined as “bad (×)”.

(10) Appearance of molded product The appearance of the container, which is a blow-molded product obtained by the hollow molding evaluation, is evaluated by visual judgment, and the state is evaluated with no unevenness and a uniform skin feel that is "good ( ○) ”, other than that, for example, those with a flow mark or those with no uniform skin feeling, those with poor air venting in the mold cavity, those having melt fracture in the parison, and the surface of the parison Finely rough skins, those whose mold cavity surface was transferred and whose transparency was lowered, etc. were defined as “defects (x)”.

(11) Presence / absence of long-chain branched structure (presence / absence of elongational viscosity):
Measurement of elongational viscosity at 170 ° C. and strain rate of 0.1 / second using a rheometer (Ales manufactured by Rheometrics) using a test piece formed into a sheet of 18 mm × 10 mm and thickness 0.7 mm by press molding The presence or absence of a long chain branched structure was confirmed by the presence or absence of rising of the extensional viscosity (presence or absence of strain hardening).
[Measurement condition]
Apparatus: Ales manufactured by Rheometrics
Jig: EXTENSIONAL VISUALITY FIXTURE, manufactured by TA Instruments
Measurement temperature: 170 ° C
Strain rate: 0.1 / second Preparation of test piece: A sheet of 18 mm × 10 mm and a thickness of 0.7 mm was formed by press molding.
[Calculation method]
The elongational viscosity at 170 ° C. and strain rate of 0.1 / second was plotted on a logarithmic graph with time t (unit: second) on the horizontal axis and elongation viscosity η (t) (unit: Pa · second) on the vertical axis. On the log-log graph, the maximum elongation viscosity until strain becomes 4.0 after strain hardening is η _Max (t1) (t1 is the time when the maximum elongation viscosity is shown), and the extension viscosity before strain hardening. when the approximate line was η _linear (t), defines the value calculated as _{η Max (t1) / η linear} (t1) strain hardening degree and (.lambda.max). The presence or absence of strain hardening was determined by whether or not there was an inflection point at which the extensional viscosity changed from an upward convex curve to a downward convex curve over time.
1 and 2 are typical plots of elongational viscosity. FIG. 1 shows a case where an inflection point of elongational viscosity is observed, and η _Max (t1) and η _Linear (t1) are shown in the figure. FIG. 2 shows a case where an inflection point of elongational viscosity is not observed.

(12) Comprehensive evaluation The hollow moldability as an ethylene / α-olefin copolymer and the suitability as a hollow molded article were comprehensively evaluated. That is, “good (◯)” was satisfied for any of the following items, and “bad (×)” for other items.
1) In the evaluation of pinch-off characteristics, tan δ is 0.50 to 0.80.
2) The tensile impact strength is 233 kJ / m ² or more.
3) FNCT is 285 hours or more.
4) The hollow moldability is good.
5) Appearance of the molded product is good.

2. Materials Used (1) Synthesis of Metallocene Catalyst A cylindrical flask fully equipped with nitrogen and equipped with an induction stirrer was charged with silica having an average particle diameter of 11 μm (average particle diameter of 11 μm, surface area of 313 m ² / g, pore volume of 1. 6 g ³ / g) was charged, 3 ml of toluene was added, and the mixture was heated to 75 ° C. with an oil bath. In a separate flask, 8.0 ml of a toluene solution of methylaluminoxane (Albemarle, 3.0 mol-Al / L) was collected. Dimethylsilylenebis [1,1 ′-{2- (2- (5-methyl) furyl) -4- (p-isopropylphenyl) -indenyl}] zirconium dichloride (63.4 mg, 75 μmol) in toluene solution (15 ml) Was added to a toluene solution of methylalumoxane at room temperature, heated to 75 ° C., and stirred for 1 hour. Subsequently, this toluene solution was added to a toluene slurry of silica heated to 75 ° C. while stirring and held for 1 hour. Thereafter, 175 ml of n-hexane was added with stirring at 23 ° C., and after 10 minutes, stirring was stopped and the mixture was allowed to stand. After the catalyst was sufficiently settled, the supernatant was removed and 200 ml of n-hexane was added. After stirring once, it was allowed to stand again to remove the supernatant. This operation was repeated 3 times to remove components liberated in n-hexane. Furthermore, the solvent was distilled off under reduced pressure while being heated at 40 ° C. After the degree of vacuum became 0.8 mmHg or less, vacuum drying was further continued for 15 minutes to obtain a silica-supported metallocene catalyst.

(2) Synthesis of Ziegler catalyst 20 g (17.8 mmol) of commercially available magnesium ethylate (average particle size 860 μm) in a nitrogen atmosphere in a pot (crushing vessel) with a volume of about 1 700 mm magnetic balls having a diameter of 10 mm in a nitrogen atmosphere. ), 1.64 g (12.3 mmol) of granular aluminum trichloride and 2.40 g (8.81 mmol) of diphenyldiethoxysilane. Next, co-grinding was performed for 3 hours using a vibration ball mill under conditions of an amplitude of 6 mm and a frequency of 30 Hz. After co-grinding, the contents were separated from the magnetic balls in a nitrogen atmosphere.
10.0 g of the co-ground product obtained as described above and 40 ml of heptane were added to a 200 ml three-necked flask. While stirring, 10.0 g (52.7 mmol) of titanium tetrachloride was added dropwise at room temperature, the temperature was raised to 90 ° C., and stirring was continued for 90 minutes. Subsequently, after cooling the reaction system, the supernatant was extracted and hexane was added. This operation was repeated three times. The obtained pale yellow solid was dried at 50 ° C. under reduced pressure for 6 hours to obtain 15.6 g of a solid catalyst.
The hexane slurry solution of this solid catalyst is put into a polymerization reactor equipped with an induction stirrer, the temperature is maintained at 40 ° C., 0.27 mmol of triisobutylaluminum is added, and the hydrogen partial pressure is 0.074 MPa and the ethylene partial pressure is 0.20 MPa. Thus, prepolymerization was performed to obtain a prepolymerized Ziegler catalyst having a polymer production amount of 0.46 g per 1 g of the solid catalyst.

(3) Synthesis of Chromium Catalyst Detailed description of the synthesis of the chromium catalyst can be found in publicly known documents including, for example, Japanese Patent Application Publication No. 2011-190437.
For example, an example is shown below. That is, 50 g of silica gel (for example, product name C-952 manufactured by Grace; trade name C-952) and 200 mL of ion-exchanged water were added to a 1 L flask equipped with a stirrer, and an aqueous solution in which 2.2 g of chromium (III) acetate was dissolved in 70 mL of ion-exchanged water was added. Then, the silica compound was thoroughly impregnated into the silica gel. Next, heating was performed to distill off the entire amount of water to obtain a greenish-white fluidity chromium catalyst precursor particle. By performing calcination activation (activation) in a calcination electric furnace in a fluidized state by a dry air stream, the chrome catalyst precursor particles can obtain an orange chrome catalyst indicating that hexavalent chromium is contained. . The firing temperature for activation is generally 350 ° C. to 850 ° C.

(4) Production of polyethylene component (D) A polymerization apparatus having a polymerization liquid-filled loop reactor is continuously supplied with dehydrated and purified isobutane, the chromium catalyst obtained in (3) above, and ethylene at 105 ° C. The component (D) was produced by polymerizing. The HLMFR of component (D) was adjusted by supplying an appropriate amount of hydrogen.

(5) Production of polyethylene component (E) In a two-tank continuous polymerization apparatus in which two polymerization liquid-filled loop reactors are connected in series, dehydrated and purified isobutane, triisobutylaluminum, and prepolymerization obtained in (2) above. The component (E) was produced by continuously supplying a Ziegler catalyst and ethylene to polymerize ethylene at 95 ° C. The HLMFR of component (E) was adjusted by supplying an appropriate amount of hydrogen.

3. Examples and Comparative Examples [Example 1]
Production of polyethylene component (B);
Component (B) was produced by carrying out ethylene / 1-hexene copolymerization using the silica-supported metallocene catalyst. That is, 800 mL of isobutane, 1.0 mL of 1-hexene, 0.10 mmol of triisobutylaluminum, Stadis450 (a mixture of polysulfone copolymer, polymer polyamine, and oil-soluble sulfonic acid) manufactured by The Associated Octel, in a 2 L autoclave with an induction stirrer Toluene dilution (2 g / L) 0.8 ml was added, the temperature was raised to 80 ° C., 50 mL of hydrogen was added, and ethylene was further introduced to keep the ethylene partial pressure at 1.0 MPa. Next, 24 mg of the metallocene catalyst was injected with nitrogen, and polymerization was continued for 32 minutes while maintaining an ethylene partial pressure of 1.0 MPa and a temperature of 80 ° C. During the polymerization reaction, H ₂ and 1-hexene were additionally supplied at a supply rate proportional to the ethylene consumption rate. The HLMFR of component (B) obtained at this time was 0.72 g / 10 min, and the density was 0.9190 g / cm ³ .

Production of polyethylene component (C);
After the component (B) was produced as described above, 130 mL of hydrogen was quickly added while maintaining the temperature and pressure, and ethylene / 1-hexene copolymerization was further continued for 88 minutes to produce the component (C). During the polymerization reaction, H ₂ and 1-hexene were additionally supplied at a supply rate proportional to the ethylene consumption rate. The HLMFR of component (C) obtained at this time was 0.72 g / 10 min, and the density was 0.9270 g / cm ³ .

Production of polyethylene component (A);
The component (B) and the component (C) were produced as described above, and 247 g of a polyethylene component (A) as a two-stage polymer was produced by continuous polymerization. The HLMFR of the component (A) was 0.72 g / 10 min, and the density was 0.9230 g / cm ³ .

Production of polyethylene resin compositions;
Three components of the polyethylene component (A), the polyethylene component (D) and the polyethylene component (E) were melt-mixed at the ratio shown in Table 1 under the following kneading conditions to produce a polyethylene resin composition. The composition had an HLMFR of 28 g / 10 min and a density of 0.9544 g / cm ³ .
[Kneading conditions]
Equipment used: Laboplast mill roller mixer manufactured by Toyo Seiki Seisakusho (mixer model: R100 / blade shape: roller type R100B)
Additive formulation: 2,000 ppm of IRGANOX B225 manufactured by BASF Japan and 1,000 ppm of calcium stearate manufactured by Tannan Chemical Industry Co., Ltd. Filling amount: 70 g / batch
Kneading temperature: 190 ° C
Blade rotation speed: 40rpm
Preheating time: 5 minutes Kneading time: 2 minutes

<Manufacture of polyethylene resin composition for molding evaluation>
In the composition having the blending ratio described in Example 1 in Table 1, 1,000 ppm of IRGANOX B225 manufactured by BASF Japan, and 500 ppm of calcium stearate manufactured by Tamnan Chemical Industry Co., Ltd. Using TEM26SX (screw diameter: 26 mm, L / D = 64), pelletization was performed under the conditions of a set temperature: 200 ° C., a screw rotation speed: 200 rpm, and a discharge amount: 15 kg / hr.
The physical properties and evaluation results of the polyethylene resin composition are shown in Table 1. The resulting composition has good compatibility of each component, excellent flowability and high melt tension, excellent hollow moldability, long break time, high tensile impact strength, and appearance of the molded product. Was good.

[Examples 2 to 4]
The same procedure as in Example 1 was performed except that the conditions were set so as to obtain the composition shown in Table 1.
In addition, in manufacture of the said polyethylene component (A), except having changed conditions about the amount of ethylene which is a main raw material, and the amount of hydrogen which is a chain transfer agent so that it may become a polymer shown in Table 1, of the said polyethylene component (A). The polyethylene component (A) of Examples 2 to 4 was obtained in the same manner as in the production.
The evaluation results of the obtained polyethylene resin composition are shown in Table 1. The obtained polyethylene resin composition had good compatibility of each component, long breaking time, high tensile impact strength, good hollow moldability, and good appearance of the molded product.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the conditions were set so as to obtain the composition shown in Table 1. However, in Comparative Example 1, polyethylene component (B) and (C) were not included as polyethylene component (A), and it was produced by single-stage polymerization. The evaluation results of the obtained polyethylene resin composition are shown in Table 1. The obtained polyethylene resin composition had a short break time and an insufficient tensile impact strength.

[Comparative Example 2]
The same procedure as in Example 1 was performed except that the conditions were set so as to obtain the composition shown in Table 1.
In addition, in manufacture of the said polyethylene component (A), except having changed conditions about the amount of ethylene which is a main raw material, and the amount of hydrogen which is a chain transfer agent so that it may become a polymer shown in Table 1, of the said polyethylene component (A). The polyethylene component (A) of Comparative Example 2 was obtained in the same manner as in the production.
The evaluation results of the obtained polyethylene resin composition are shown in Table 1. The obtained polyethylene resin composition had a short rupture time, a low tensile impact strength, a poor hollow moldability, and an appearance of a molded product was not good.

[Comparative Example 3]
The same procedure as in Example 1 was performed except that the conditions were set so as to obtain the composition shown in Table 1.
In addition, in manufacture of the said polyethylene component (A), except having changed conditions about the amount of ethylene which is a main raw material, and the amount of hydrogen which is a chain transfer agent so that it may become a polymer shown in Table 1, of the said polyethylene component (A). The polyethylene component (A) of Comparative Example 3 was obtained in the same manner as in the production.
The evaluation results of the obtained polyethylene resin composition are shown in Table 1. The obtained polyethylene resin composition had a short rupture time, a low tensile impact strength, a poor hollow moldability, and an appearance of a molded product was not good.

  It can be seen that Examples 1 to 4 have a longer fracture time and a higher tensile impact strength than Comparative Examples 1 to 3. Moreover, it turns out that Examples 1-4 are excellent in the hollow moldability and the external appearance of a molded article compared with Comparative Examples 2-3.

According to the present invention, it is excellent in hollow moldability, environmental stress crack resistance and impact resistance, can be molded thinner and lighter, has a high crystallization speed, excellent high-speed moldability, and has a high molding cycle. It is possible to provide a polyethylene resin composition having good pinch-off characteristics, high compatibility of resin components, and particularly excellent appearance of the molded article, and a molded article comprising the same.
Further, the polyethylene resin composition of the present invention is excellent in high fluidity during molding, and the molded product of the present invention is excellent in odor, food safety, rigidity, heat resistance and the like.
Therefore, the polyethylene resin composition of the present invention and the molded product thereof are suitable for uses such as containers that require such characteristics, and in particular, cosmetic containers, detergents, shampoos and rinse containers with excellent appearance, edible oils, etc. It can use suitably for uses, such as a food container.
Furthermore, containers using the polyethylene resin composition of the present invention can be molded at a high speed and have a high cycle, have excellent product characteristics, and are economically advantageous, such as cosmetic containers, detergents, shampoos and rinses. Suitable as a container.
Further, since the polyethylene resin composition of the present invention is excellent in performance as described above, it can be suitably used for kerosene cans, chemical containers, and the like that require such characteristics in addition to the above containers. This is very useful in industry.

Claims (5)

10 mass% to 40 mass% of the following polyethylene component (A), 5 mass% to 50 mass% of the following polyethylene component (D), 40 mass% to 85 mass% of the following polyethylene component (E), A polyethylene resin composition satisfying the following characteristics (1) to (5).
Polyethylene component (A); Characteristic (a1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.2 g / 10 min or more and 5 g / 10 min or less, and characteristic (a2): density is 0.915 g / cm ³ or more and 0.945 g / cm ³ or less, characteristic (a3): the following polyethylene component (B) and the following polyethylene component (C), (B) :( C) = 5: 95- Polyethylene containing at a ratio of 95: 5 (mass%).
Polyethylene component (B); Characteristic (b1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 kg is 0.2 g / 10 min or more and 2 g / 10 min or less, and characteristic (b2): density is 0.900 g / cm ³ or more 0.950 g / cm ³ polyethylene satisfy the following.
Polyethylene component (C); Characteristic (c1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 0.4 g / 10 min or more and 10 g / 10 min or less, and characteristic (c2): density is 0.900 g / cm ³ or more 0.970 g / cm ³ polyethylene satisfy the following.
Polyethylene component (D); Characteristic (d1): Melt flow rate (HLMFR) at a temperature of 190 ° C. and a load of 21.6 Kg is 2 g / 10 min or more and 20 g / 10 min or less. 945 g / cm ³ or more 0.965 g / cm ³ or less, the characteristics (d3): temperature 170 ° C., elongation strain rate 0.1: elongation viscosity measured at (in 1 / sec) eta (t) (unit: Polyethylene in which an inflection point of elongational viscosity due to strain hardening is observed in a logarithmic plot of Pa · second) and elongation time t (unit: second).
Polyethylene component (E); characteristic (e1): a melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg is 10 g / 10 min or more and 200 g / 10 min or less, and characteristic (e2): a density of 0.1. 960 g / cm ³ or more 0.980 g / cm ³ polyethylene satisfy the following.
Characteristic (1): MFR is 0.1 g / 10 min or more and 1 g / 10 min or less.
Characteristic (2): HLMFR is 10 g / 10 min or more and 50 g / 10 min or less.
Characteristic (3): Melt flow rate ratio (HLMFR / MFR) which is a ratio of HLMFR to MFR is 50 or more and 140 or less.
Characteristics (4): density of 0.940 g / cm ³ or more 0.965 g / cm ³ or less.
Characteristic (5): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 0.1 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed. Furthermore, the polyethylene resin composition of Claim 1 which satisfies the following characteristic (6).
Characteristic (6): Fracture time (FNCT) at 80 ° C. and 3.7 MPa by a full notch creep test is 285 hours or more. Furthermore, the polyethylene resin composition of Claim 1 or 2 which satisfies the following characteristic (7).
Characteristic (7): Tensile impact strength is 233 kJ / m ² or more.   The molded object created using the polyethylene resin composition as described in any one of Claims 1-3.   The container created using the polyethylene resin composition as described in any one of Claims 1-3.