JP2018009166A - Polyethylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition containing high density polyethylene for producing a film excellent in tearability, sealability and coating property.SOLUTION: A polyethylene resin composition has a density of 930-960 kg/mand a melt flow rate at 190°C and 2.16 kg of 1-20 g/10 min, where when TREF (temperature-rising elution fractionation method) measurement is performed using a CFC device on the following conditions, the polyethylene resin composition exhibits one or more peaks of an elution temperature-elution quantity curve at 80°C or lower and one or more peaks thereof at 90°C or higher, exhibits a peak becoming the maximum value (Wmax) of an elution amount at 90°C or higher, and has the maximum value of 10 wt.% or more with respect to the total elution amount. (1) weighing 20 mg of the polyethylene resin composition, and injecting 0.5 ml of o-dichlorobenzene to the polyethylene resin composition; (2) holding the polyethylene resin composition at 140°C for 120 minutes and completely dissolving the polyethylene resin composition, and introducing a solution to a TREF column; (3) decreasing the temperature from 140°C to 40°C at 0.5°C/min, precipitating the polyethylene resin composition to a column, and then holding the polyethylene resin composition at 40°C for 20 minutes; and (4) rising the temperature from 40°C to 140°C by 1°C and keeping the temperature for 15 minutes after rise of the temperature at each temperature, then performing the TREF measurement, and measuring the elution amount.SELECTED DRAWING: None

Description

  The present invention relates to a polyethylene resin composition.

  In general, polyethylene is used as a raw material for many films and sheets such as food packaging films, pharmaceutical packaging films, and agricultural sheets. Among them, many polyethylenes are used for individual packaging of retort food packaging materials, food wraps, and confectionery.

Polyethylene is roughly divided into two types depending on the production method. The first is polyethylene synthesized at a relatively low pressure by a catalyst, and can be classified into three types: high-density polyethylene, medium-density polyethylene, and linear low-density polyethylene. The second is a high-pressure low-density polyethylene synthesized at a relatively high pressure using a radical initiator.
Examples of the catalyst used for polyethylene synthesis include a Ziegler catalyst and a metallocene catalyst. Polyethylene synthesized with a metallocene catalyst is used in many fields, taking advantage of its narrow molecular weight distribution and composition distribution.

For example, the following Patent Document 1 describes an invention using a high-density polyethylene using a metallocene catalyst as a main raw material, but is insufficient in terms of tearability, and there is no mention of hand cutting properties. .
Moreover, although the literature (for example, refer patent document 2) of the extending | stretching film of an ethylene-type resin is seen by the point of tearability improvement, extending | stretching equipment is required and it is not desirable from the surface of equipment cost.
Furthermore, a technique for applying a material such as an antistatic agent is known for imparting a function of a polyethylene film, but unevenness and repelling of the material occur when applying, and problems remain in uniform application (for example, (See Patent Document 3).
In addition, for example, a multilayer laminate film often used in food packaging or the like as described in Patent Document 4 requires seal strength as the application spreads, and there are many requests for improvement.

Japanese Patent No. 5713438 Japanese Examined Patent Publication No. 61-41732 Japanese Patent Laid-Open No. 1-313532 JP2015-128894A

  An object of this invention is to provide the polyethylene resin composition for making the film excellent in tearability, hand tearability, sealability, and applicability | paintability with an unstretched film in view of the above situations.

As a result of conducting extensive research to solve the above-mentioned problems, the present inventors have found that a resin composition containing high-density polyethylene that satisfies predetermined physical property conditions solves the above-described problems, and has led to the present invention. .
That is, the present invention is as follows.

[1]
A polyethylene resin composition having a density of 930 to 960 kg / m ³ , a melt flow rate at 190 ° C. and 2.16 kg of 1 to 20 g / 10 min, and using a CFC apparatus under the following conditions, TREF (temperature rising elution) Fractionation method) When the measurement is performed, the peak of the elution temperature-elution amount curve appears at 1 or more at 80 ° C. or lower and at least 1 at 90 ° C. or higher, and the peak at the maximum elution amount (Wmax) is 90 ° C. A polyethylene resin composition which is expressed as described above, and whose maximum value is 10% by weight or more of the total elution amount.
(1) Weigh 20 mg of the polyethylene resin composition and inject 0.5 ml of o-dichlorobenzene;
(2) Hold at 140 ° C. for 120 minutes to completely dissolve the polyethylene resin composition, and introduce the solution into a TREF column;
(3) The temperature is decreased from 140 ° C. to 40 ° C. at 0.5 ° C./min, and deposited on the column, and then held at 40 ° C. for 20 minutes;
(4) Raise the temperature from 40 ° C to 140 ° C by 1 ° C, hold the temperature for 15 minutes or more after raising the temperature at each temperature, then perform TREF measurement and measure the elution amount [2]
The polyethylene resin according to [1], wherein the ratio of the maximum elution amount (Wmax) to the maximum elution amount (W1) at an elution temperature of 60 to 80 ° C. in TREF measurement, Wmax / W1 is 2.0 or more. Composition.
[3]
The polyethylene resin composition according to [1] or [2], comprising 30 to 80% by mass of the high-density polyethylene resin (A) and 20 to 70% by mass of the high-pressure method low-density polyethylene resin (B).
[4]
In DSC measurement, ½ isothermal crystallization time when melted at 180 ° C. for 5 minutes and measured at 1 ° C. above the extrapolation crystallization start temperature (Tic) under the condition of a temperature drop rate of 80 ° C./min. The polyethylene resin composition according to any one of [1] to [3], which is 0.7 minutes or longer.
[5]
The polyethylene resin composition according to [3] or [4], wherein the high-density polyethylene resin (A) is an ethylene homopolymer, an ethylene-propylene copolymer, or an ethylene-butene copolymer.
[6]
The high-density polyethylene resin (A) comprises (a) a carrier material; (b) an organoaluminum compound; (c) a transition metal compound having a cyclic η-bonding anion ligand; and (d) the cyclic η-bonding anion coordination. Polymerization using a supported metallocene catalyst (C) prepared from an activator capable of forming a complex that exhibits catalytic activity by reacting with a transition metal compound having a child, and a liquid promoter component (D) The polyethylene resin composition according to any one of [3] to [5], which is produced by
[7]
The polyethylene resin composition according to any one of [1] to [6], wherein a chlorine atom content is less than 2.0 mass ppm with respect to the polyethylene resin composition.

  According to the present invention, a non-stretched film has good tearability and hand cutting properties, is excellent in coating properties with an antistatic agent and in sealing properties when a multilayer film is formed, and produces a clean and low-staining film. A polyethylene resin composition can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to this embodiment, It can implement in various deformation | transformation within the range of the summary.

[Polyethylene resin composition]
The polyethylene resin composition of this embodiment has a density of 930 to 960 kg / m ³ , a melt flow rate of 1 to 20 g / 10 min at 190 ° C. and 2.16 kg, and TREF (increased) under the following conditions using a CFC device. (Warm elution fractionation method) When the measurement is carried out, the peak of the elution temperature-elution amount curve is one or more at 80 ° C. or less and one or more at 90 ° C. or more, and the peak of the elution amount is the maximum value (Wmax) It is a polyethylene resin composition that develops at 90 ° C. or more and has a maximum value of 10% by weight or more of the total elution amount.
(1) Weigh 20 mg of the polyethylene resin composition and inject 0.5 ml of o-dichlorobenzene;
(2) Hold at 140 ° C. for 120 minutes to completely dissolve the polyethylene resin composition, and introduce the solution into a TREF column;
(3) The temperature is decreased from 140 ° C. to 40 ° C. at 0.5 ° C./min, and deposited on the column, and then held at 40 ° C. for 20 minutes;
(4) Raise the temperature by 1 ° C from 40 ° C to 140 ° C, hold the temperature for 15 minutes or more after raising the temperature at each temperature, perform TREF measurement, and measure the elution amount

The composition of the polyethylene resin composition of this embodiment is shown below, but the present invention is not limited to the following two types of polyethylene. As an example of this embodiment, a manufacturing method using an extruder of a high density polyethylene resin (A) and a high pressure method low density polyethylene resin (B) will be described.
The manufacturing method of the polyethylene resin composition of the present embodiment comprises a high-density polyethylene resin (A) and a high-pressure method low-density polyethylene resin (B), a high-density polyethylene resin (A) and a high-pressure method low-density polyethylene resin (B). The MFR ratio (A) / (B) is 0.5 to 15 and the density ratio (A) / (B) of the high-density polyethylene resin (A) and the high-pressure low-density polyethylene resin (B) is 1. It is preferable to melt-knead a thing of 025 or more. When the MFR ratio (A) / (B) is lower than 0.5, the moldability is deteriorated, and when the MFR ratio (A) / (B) is larger than 15, poor dispersion occurs. When the MFR ratio and density ratio are in the above ranges, the compatibility with (B) tends to be improved while retaining the highly crystallized component of (A).
The blending ratio of the high density polyethylene resin (A) and the high pressure method low density polyethylene resin (B) is 30 to 80% by mass of the high density polyethylene resin (A) and 20 to 70% by mass of the high pressure method low density polyethylene resin (B). Preferably there is. More preferably, they are 40-70 mass% of high-density polyethylene resin (A), and 30-60 mass% of high-pressure method low-density polyethylene resins (B).

  The polyethylene resin composition of this embodiment can be prepared by kneading pellets of a high-density polyethylene resin (A) and a high-pressure method low-density polyethylene resin (B) with an extruder. The pellets of the high-density polyethylene resin (A) and the high-pressure method low-density polyethylene resin (B) include the weight of the high-density polyethylene resin (A) per piece and the high-pressure method low-density polyethylene resin (B) per piece. It is preferable to make the difference from the weight of the above so as to be in the range of ± 1.0 mg. The particle sizes of different types of pellets, that is, the weight per one, are uniform, and it becomes difficult to classify in the hopper directly above the extruder, and the dispersibility tends to be improved. In addition, let the weight per pellet be the average value which measured the weight of 20 pellets.

  The dispersibility of the resins (A) and (B) in the polyethylene resin composition of the present embodiment affects the tear strength. That is, when the dispersibility is low and unevenness occurs in the mixed state of the resins (A) and (B), the film obtained from the polyethylene resin composition becomes a film having poor tearability. Moreover, in the film obtained from the polyethylene resin composition having low dispersibility, there is a defect that the film is torn in a zigzag pattern or in an oblique direction without tearing straight during the hand cutting test. Therefore, it is desirable that the resins (A) and (B) are thoroughly mixed at the molecular level.

  Examples of the extruder used for kneading the pellets of the high-density polyethylene resin (A) and the high-pressure low-density polyethylene resin (B) include a single-screw or twin-screw extruder, and any of these extruders May be used.

  The polyethylene resin composition of the present embodiment has a maximum elution amount (Wmax) of 10% by weight or more of the total elution amount when measured by TREF (temperature rising elution fractionation method) using a CFC apparatus under the following conditions. When the TREF measurement is performed, the maximum value of the elution amount being 10% by weight or more indicates that the melting point distribution of the polyethylene resin composition is narrow. That is, it shows that crystals having a relatively uniform size are generated when cooled. The uniform crystal size in the film indicates that the tear cracks are likely to propagate when tearing, and exhibits good tearability. The maximum elution amount is preferably 12% by weight or more, and more preferably 13 to 17.5% by weight.

  Furthermore, it is preferable that the temperature which shows the maximum value of elution amount is 90 degreeC or more from a viewpoint of the tearability of a film. 92-105 degreeC is preferable and the temperature which shows the maximum value has more preferable 93-100 degreeC.

  In TREF measurement, the ratio between Wmax and the mass fraction (W1) of the maximum elution amount at a temperature of 60 to 80 ° C. in TREF measurement with respect to the total elution amount, Wmax / W1 is an index indicating the optimum value of tearability. That is, when Wmax / W1 is less than 2.0, the resin (A) decreases, the number of crystals having a relatively uniform size decreases, and the resin (B) with many branches increases. As a result, the tear strength is increased and the tearability is lowered. Therefore, Wmax / W1 is preferably 2.0 or more, and more preferably 2.3 or more. Although the upper limit of Wmax / W1 is not limited, it is assumed that it does not exceed 6 in view of the content of the resin (B) defined in this patent.

  When the polyethylene resin composition of the present embodiment is measured at 1 ° C. above the extrapolation crystallization start temperature (Tic) under the conditions of melting at 180 ° C. for 5 minutes and decreasing the temperature at a temperature decrease rate of 80 ° C./min in DSC measurement. The ½ isothermal crystallization time is preferably 0.7 minutes or more. Even more preferably, it is 0.8 minutes or more. At the time of film formation from the above polyethylene resin composition, the resin melted in the extruder is extruded from the lip opening of the T die and cooled instantaneously by the cooling roll, but the crystallization speed at that time is slow. The proportion of crystallized polyethylene in is low. In particular, the crystallization ratio of the crystallized polyethylene derived from the resin (A) is lowered. The crystal part of the crystallized polyethylene is relatively hard. When the proportion of such crystals decreases, the amorphous part having a relatively low strength increases. Therefore, tearing is easily propagated by the amorphous part, so that tearability is improved.

The chlorine content of the polyethylene resin composition is preferably 2.0 mass ppm or less, more preferably 1.0 mass ppm or less, based on the polyethylene resin composition. When the chlorine content of the polyethylene resin composition is 2.0 mass ppm or less with respect to the polyethylene resin composition, corrosion of a molding machine or the like can be suppressed, and the amount of metal components contained in the polymer can be reduced. . Furthermore, even when it is used as a surface protective film for a protected material such as a metal that is easily affected by chlorine and hydrochloric acid, rust of the protected material tends to be suppressed. Furthermore, since there is little chlorine content, the addition to the polyethylene composition of the neutralizing agent represented by the fatty acid salt can be avoided. As a result, it is possible to prevent the neutralizing agent from bleeding out of the molded body, the formation of eyes and particles during molding, and a clean molded product with low contamination can be obtained.
The chlorine content of the polyethylene resin composition can be controlled by appropriately adjusting the polymerization conditions and the like using a catalyst described later. Moreover, the chlorine content of a polyethylene resin composition can be measured by the method as described in an Example.

[High-density polyethylene (A)]
The high-density polyethylene (A) in the present embodiment is specifically a polyethylene homopolymer or ethylene and α-olefin copolymer, and from the viewpoint of tearability when the polyethylene resin composition is used as a film, An ethylene homopolymer, an ethylene-propylene copolymer or an ethylene-butene copolymer is preferred.
The high-density polyethylene (A) in the present embodiment can be produced by the following production method using a supported metallocene catalyst (C) (hereinafter also referred to as a supported geometrically constrained metallocene catalyst). The high-density polyethylene resin (A) in this embodiment is preferably (a) an inorganic carrier material; (b) an organoaluminum compound; (c) a transition metal compound having a cyclic η-bonding anion ligand; D) a supported metallocene catalyst (C) prepared from an activator capable of reacting with a transition metal compound having the cyclic η-bonding anion ligand to form a complex that exhibits catalytic activity; and a liquid promoter It manufactures by superposing | polymerizing using a component (D).

The density (JIS K7112) of the high-density polyethylene resin (A) of the present embodiment is preferably 940 kg / m ³ or more, more preferably 942 kg / m ² from the viewpoint of tearability when the polyethylene resin composition is used as a film. m ³ or more, more preferably 945 kg / m ³ or more.
The upper limit of the density of the high-density polyethylene resin (A) is not particularly limited, but is preferably 970 kg / m ³ or less.
The density of the high density polyethylene resin (A) can be controlled by the content of α-olefin in the high density polyethylene resin. It can be controlled by the manufacturing conditions. Moreover, the density of a high-density polyethylene resin (A) can be measured by the method as described in an Example.

The high-density polyethylene resin (A) of this embodiment has a melt flow rate (JIS K7210) of 190 ° C. and 2.16 kg of preferably 1 to 70 g / 10 minutes, more preferably 8 to 50 g / 10 minutes, Preferably it is 12-40 g / 10min.
When the MFR of the high-density polyethylene resin (A) is 1 g / 10 min or more, a film having a melt viscosity that can be processed without being too high in tear strength can be formed. Moreover, since the high-density polyethylene of 70 g / 10 min or more has a viscosity at the time of melting that is too low, it is difficult to mold it as a film. Specifically, in the T-die molding, there is a problem that the neck-in between the T-die and the cooling roll is too large and a wide film cannot be obtained, and in the inflation molding, the parison is deformed and does not stand up.
The melt flow rate of the high-density polyethylene resin (A) can be adjusted by changing the polymerization temperature or using hydrogen as a chain transfer agent. The melt flow rate of the high-density polyethylene resin (A) can be measured by the method described in the examples.

  The molecular weight distribution Mw / Mn of the high-density polyethylene resin (A) of this embodiment is preferably 2 to 6, more preferably 2.5 to 5.5, still more preferably 3 to 3, from the viewpoint of processability. 5. The molecular weight distribution Mw / Mn of the high-density polyethylene resin (A) can be controlled by the production conditions.

  The supported geometrically constrained metallocene catalyst (C) that can be used in the production process of the high-density polyethylene (A) is not particularly limited, but at least (a) an inorganic carrier material (hereinafter referred to as “component (a)”, “( A) "), (a) an organoaluminum compound (hereinafter also referred to as" component (a) "," (a) "), (c) a transition metal compound having a cyclic η-bonding anion ligand (Hereinafter also referred to as “component (U)” and “(U)”)), and (d) forming a complex that exhibits catalytic activity by reacting with a transition metal compound having the cyclic η-bonding anion ligand. It can be prepared using a possible activator (hereinafter also referred to as “component (D)” or “(D)”).

(A) The inorganic carrier material is not particularly limited, and examples thereof include oxides such as SiO ₂ (silica), Al ₂ O ₃ , MgO, and TiO ₂ ; halogen compounds such as MgCl ₂ . Of these, the preferred support material is SiO ₂ .
(A) The average particle size of the inorganic carrier substance is 1.0 μm or more and 50 μm or less, preferably 2.0 μm or more and 40 μm or less, more preferably 3.0 μm or more and 30 μm or less. The average particle diameter of the inorganic carrier substance is an average particle diameter in terms of volume in a measuring method by a laser light scattering method. Specifically, it can be measured using “SALD-2100” manufactured by Shimadzu Corporation.
(A) The compressive strength of the inorganic carrier material is 1 MPa or more and 30 MPa or less, preferably 2 MPa or more and 25 MPa or less, more preferably 3 MPa or more and 20 MPa or less.
(A) The compressive strength of the inorganic carrier material is an index of ease of cracking, and the lower the value, the easier it is to crack. Specifically, the compressive strength of the inorganic carrier material is determined by measuring the crushing strength of 10 or more particles arbitrarily selected using “Micro Compression Tester MCT-510” manufactured by Shimadzu Corporation, and calculating the average value. It can be a compressive strength.
(A) Since the average particle diameter and compressive strength of the inorganic carrier material are within the above-mentioned ranges, the surface is partially crushed by increasing the number of stirring revolutions during catalyst preparation, and the catalyst active point is supported inside the carrier material. When the catalyst is subjected to polymerization, polyethylene having high crystallinity tends to be generated inside the catalyst.

(A) The inorganic carrier material is preferably treated with (a) an organoaluminum compound as necessary.
Here, the “treatment” means that the inorganic carrier substance is stirred and dispersed in an inert solvent while (i) the organoaluminum compound is added dropwise and stirred at 0 ° C. to 70 ° C. for 30 minutes or longer to obtain the inorganic carrier substance. It means that the active hydrogen on the surface reacts with the organoaluminum compound.
Preferred (a) organoaluminum compounds include, but are not limited to, for example, alkylaluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum; diethylaluminum hydride, diisobutylaluminum Examples include alkylaluminum hydrides such as hydride; aluminum alkoxides such as diethylaluminum ethoxide and dimethylaluminum methoxide; and alumoxanes such as methylalumoxane, isobutylalumoxane, and methylisobutylalumoxane.
Among these, trialkylaluminum and aluminum alkoxide are preferable, and trimethylaluminum, triethylaluminum, and triisobutylaluminum are more preferable.

  The supported geometrically constrained metallocene catalyst includes (c) a transition metal compound having a cyclic η-bonding anion ligand (hereinafter also simply referred to as “transition metal compound”). The “transition metal compound” is not particularly limited, and can be represented by, for example, the following formula (1).

L _l MX _p X ' _q (1)

In formula (1), M represents a transition metal belonging to Group 4 of the periodic table having an oxidation number of +2, +3, or +4 and having η5 bond with one or more ligands L.
In the formula (1), each L independently represents a cyclic η-bonding anion ligand.
The cyclic η-bonding anion ligand is, for example, a cyclopentadienyl group, an indenyl group, a tetrahydroindenyl group, a fluorenyl group, a tetrahydrofluorenyl group, or an octahydrofluorenyl group, and these groups are represented by 20 Hydrocarbon groups, halogens, halogen-substituted hydrocarbon groups, aminohydrocarbyl groups, hydrocarbyloxy groups, dihydrocarbylamino groups, hydrocarbylphosphino groups, silyl groups, aminosilyl groups, hydrocarbyloxysilyl groups and halosilyls containing up to 1 non-hydrogen atom Optionally having 1 to 8 substituents each independently selected from a group, and two Ls containing up to 20 non-hydrogen atoms hydrocarbadiyl, halohydrocarbadiyl, hydrocarbyleneoxy , Hydrocarbyleneamino, siladiyl, halosiladi Le, may be linked by a divalent substituent such as an amino Sila-diyl.
In formula (1), each X is independently a monovalent anionic σ-bonded ligand having up to 60 non-hydrogen atoms, or a divalent anionic σ-bonded bond that binds to M in a divalent manner. A ligand or a divalent anionic σ-bonded ligand that binds to M and L with a monovalent valence each is shown.
In the formula (1), X ′ each independently represents a neutral Lewis base coordination compound selected from phosphine, ether, amine, olefin and conjugated diene, each having 4 to 40 carbon atoms.
In formula (1), l represents an integer of 1 or 2.
In the formula (1), p represents an integer of 0, 1 or 2, and X is a monovalent anionic σ-bonded ligand or a divalent bond which binds to M and L at a valence of 1 each. When an anionic σ-bonded ligand is represented, p represents an integer of 1 or more less than the formal oxidation number of M, and X is a divalent anionic σ-bonded ligand that binds to M in a divalent manner. P represents an integer that is 1 + 1 or more less than the formal oxidation number of M.
In the formula (1), q represents an integer of 0, 1 or 2.

  As for l in the (c) transition metal compound represented by Formula (1), 1 is preferable.

  (U) A suitable example of the transition metal compound is a compound represented by the following formula (2).

In the formula (2), M represents titanium, zirconium or hafnium having a formal oxidation number of +2, +3 or +4.
In formula (2), each R ¹ independently represents hydrogen, a hydrocarbon group, a silyl group, a germyl group, a cyano group, a halogen, or a composite group thereof, each of which is up to 20 non-hydrogens. It may have an atom, and adjacent R ¹ may be combined to form a divalent derivative such as hydrocarbadiyl, siladiyl, or germanadyl, and may be cyclic.
In formula (2), X ″ each independently represents a halogen, a hydrocarbon group, a hydrocarbyloxy group, a hydrocarbylamino group or a silyl group, each having up to 20 non-hydrogen atoms, Two X ″ may form a neutral conjugated diene or divalent derivative having 5 to 30 carbon atoms.
In formula (2), Y represents —O—, —S—, —NR ³ — or —PR ³ —, and Z represents —SiR ³ ₂ —, —CR ³ ₂ —, —SiR ³ ₂ —SiR. _{^{3 2 -, - CR 3 2}} -CR 3 2 -, - CR 3 = CR 3 -, - CR 3 2 -SiR 3 2 -, or, -GeR ³ ₂ - shows, where R ³ are each independently Represents an alkyl group having 1 to 12 carbon atoms or an allyl group.
Moreover, in Formula (2), n shows the integer of 1-3.

  (C) More preferable examples of the transition metal compound are compounds represented by the following formula (3) and the following formula (4).

In formulas (3) and (4), each R ¹ independently represents hydrogen, a hydrocarbon group, a silyl group, a germyl group, a cyano group, a halogen, or a composite group thereof, each of up to 20 Can have non-hydrogen atoms.
In the formulas (3) and (4), M represents titanium, zirconium or hafnium.
In the formulas (3) and (4), Z and Y are the same as those shown in the formula (2).
In the formulas (3) and (4), X and X ′ are the same as those represented by X ″ in the formula (2).
In formulas (3) and (4), p represents 0, 1 or 2, and q represents 0 or 1, respectively. When p is 2 and q is 0, the oxidation number of M is +4 and X is halogen, hydrocarbon group, hydrocarbyloxy group, dihydrocarbylamide group, dihydrocarbyl phosphide group, hydrocarbyl sulfide group, silyl group A group or a composite group thereof having up to 20 non-hydrogen atoms.
In the formulas (3) and (4), when p is 1 and q is 0, the oxidation number of M is +3 and X is an allyl group, 2- (N, N-dimethylaminomethyl) phenyl A stabilized anionic ligand selected from the group and 2- (N, N-dimethyl) -aminobenzyl group; whether the oxidation number of M is +4 and X represents a derivative of a divalent conjugated diene M and X together form a metallocyclopentene group.
In formulas (3) and (4), when p is 0 and q is 1, respectively, the oxidation number of M is +2, and X ′ is a neutral conjugated or non-conjugated diene, optionally It may be substituted with one or more hydrocarbon groups and X ′ may contain up to 40 carbon atoms, forming a π-type complex with M.

  (C) Further preferred examples of the transition metal compound are compounds represented by the following formulas (5) and (6).

In formula (5) and formula (6), each R ¹ independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms. M represents titanium, and Y represents —O—, —S—, —NR ³ —, or —PR ³ —.
In the formula (5) and (6), Z _{^{is, -SiR 3 2 -, - CR}} 3 2 -, - SiR 3 2 -SiR 3 2 -, - CR 3 2 -CR 3 2 -, - CR 3 = CR ³ —, —CR ³ ₂ —SiR ³ ₂ —, or —GeR ³ ₂ — is represented, and each R ³ independently represents hydrogen, a hydrocarbon group, a hydrocarbyloxy group, a silyl group, or a halogenated alkyl group. , An allyl halide group, or a composite group thereof, which can have up to 20 non-hydrogen atoms, and optionally, two R ³ in Z or R in Z ³ and R ^{3 in} Y may be combined to form a ring.
In Formula (5) and Formula (6), X and X ′ are the same as those shown in Formula (3) or Formula (4).
In formulas (5) and (6), p represents 0, 1 or 2, and q represents 0 or 1, respectively. However, when p is 2 and q is 0, the oxidation number of M is +4, and X each independently represents a methyl group or a benzyl group. When p is 1 and q is 0, the oxidation number of M is +3 and X represents 2- (N, N-dimethyl) aminobenzyl or the oxidation number of M is +4. X represents 2-butene-1,4-diyl. When p is 0 and q is 1, the oxidation number of M is +2, and X ′ represents 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene. These dienes are examples of asymmetric dienes that form metal complexes, and are actually a mixture of geometric isomers.

  The (U) transition metal compound is, for example, [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium dimethyl, [(Nt-butylamide) (tetramethyl-η5- Cyclopentadienyl) dimethylsilane] titanium dichloride, [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium 1,3-pentadiene, and [(Nt-butyramide) ( Tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium diphenyl and the like are preferable, and [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium dimethyl is more preferable.

The supported geometrically constrained metallocene catalyst is an activator (hereinafter simply referred to as “(d) activator”, “activator”) that can form a complex that exhibits catalytic activity by reacting with (d) a transition metal compound. ").
In general, in a metallocene catalyst, a complex formed by (c) a transition metal compound and the above (d) activator exhibits high olefin polymerization activity as a catalytically active species.
In the method for producing high-density polyethylene (A) in the present embodiment, (d) the activator is not particularly limited, and examples thereof include a compound represented by the following formula (7).

[L−H] _d ⁺ [M _m Q _p ] _d ⁻ (7)

In formula (7), [L—H] _d ⁺ represents a proton-providing Bronsted acid, and L represents a neutral Lewis base.
In Formula (7), [M _m Q _p ] _d ⁻ represents a compatible non-coordinating anion, and M represents a metal or metalloid selected from Groups 5 to 15 of the periodic table. , Q each independently represents a hydride, a dialkylamide group, a halide, an alkoxy group, an allyloxy group, a hydrocarbon group, or a substituted hydrocarbon group having up to 20 carbon atoms, and Q that is a halide is 1 or less It is.
In formula (7), m represents an integer of 1 to 7, p represents an integer of 2 to 14, d represents an integer of 1 to 7, and pm = d.

  (D) A more preferred example of the activator is a compound represented by the following formula (8).

[L−H] _d ⁺ [M _m Q _n (G _q (T−H) _r ) _z ] _d ⁻ (8)

In formula (8), [L—H] _d ⁺ represents a proton-providing Bronsted acid, and L represents a neutral Lewis base.
In the formula (8), [M _m Q _n (G _q (T−H) _r ) _z ] _d ⁻ represents a compatible non-coordinating anion, and M represents Group 5 to 5 of the periodic table. Represents a metal or metalloid selected from Group 15, and each Q independently represents a hydride, a dialkylamide group, a halide, an alkoxy group, an allyloxy group, a hydrocarbon group, or a substituted hydrocarbon group having up to 20 carbon atoms, Moreover, Q which is a halide is 1 or less.
In the formula (8), G represents a polyvalent hydrocarbon group having a valence of r + 1 bonded to M and T, and T represents O, S, NR, or PR. Here, R represents hydrocarbyl, trihydrocarbylsilyl group, trihydrocarbylgermyl group or hydrogen.
In formula (8), m represents an integer of 1 to 7, n represents an integer of 0 to 7, q represents an integer of 0 or 1, and r represents an integer of 1 to 3. Z represents an integer of 1 to 8, d represents an integer of 1 to 7, and n + z−m = d.

  (D) A more preferred example of the activator is a compound represented by the following formula (9).

[L-H] ⁺ [BQ ₃ Q ₁ ] ^- (9)

In the formula (9), [L—H] ⁺ represents a proton-providing Bronsted acid, and L represents a neutral Lewis base.
In the formula (9), [BQ ₃ Q ₁ ] ⁻ represents a compatible non-coordinating anion, B represents a boron element, Q ³ represents a pentafluorophenyl group, and Q ¹ represents And a substituted allyl group having 6 to 20 carbon atoms having one OH group as a substituent.

  Examples of the proton-providing Bronsted acid in the formulas (7), (8), and (9) include, but are not limited to, triethylammonium, tripropylammonium, tri (n-butyl) ammonium, trimethylammonium, Tributylammonium, tri (n-octyl) ammonium, diethylmethylammonium, dibutylmethylammonium, dibutylethylammonium, dihexylmethylammonium, dioctylmethylammonium, didecylmethylammonium, didodecylmethylammonium, ditetradecylmethylammonium, dihexadecyl Such as methylammonium, dioctadecylmethylammonium, diicosylmethylammonium, and bis (hydrogenated tallow alkyl) methylammonium Trialkyl group-substituted ammonium cation; N, N-dimethylanilinium, N, N-diethylanilinium, N, N-2,4,6-pentamethylanilinium, N, N-dimethylbenzylanilinium, etc. Such N, N-dialkylanilinium cations; and triphenylcarbonium cations. Among these proton-providing Bronsted acids, a trialkyl group-substituted ammonium cation is preferable, and bis (hydrogenated tallow alkyl) methylammonium is more preferable.

  Examples of the compatible non-coordinating anion in the formulas (7), (8) and (9) include, but are not limited to, triphenyl (hydroxyphenyl) borate, diphenyl-di (hydroxyphenyl) borate, Triphenyl (2,4-dihydroxyphenyl) borate, tri (p-tolyl) (hydroxyphenyl) borate, tris (pentafluorophenyl) (hydroxyphenyl) borate, tris (2,4-dimethylphenyl) (hydroxyphenyl) borate , Tris (3,5-dimethylphenyl) (hydroxyphenyl) borate, tris (3,5-di-trifluoromethylphenyl) (hydroxyphenyl) borate, tris (pentafluorophenyl) (2-hydroxyethyl) borate, tris (Pentafluoropheny ) (4-hydroxybutyl) borate, tris (pentafluorophenyl) (4-hydroxy-cyclohexyl) borate, tris (pentafluorophenyl) (4- (4′-hydroxyphenyl) phenyl) borate, and tris (pentafluorophenyl) ) (6-hydroxy-2-naphthyl) borate. These compatible non-coordinating anions are also referred to as “borate compounds”.

  From the viewpoint of catalytic activity and the viewpoint of reducing the total content of Al, Mg, Ti, Zr and Hf, the activator of the supported geometrically constrained metallocene catalyst contains a borate compound as a compatible non-coordinating anion. It is preferable. Preferred borate compounds include tris (pentafluorophenyl) (4-hydroxyphenyl) borate.

  (D) As the activator, an organometallic oxy compound having a unit represented by the following formula (10) can also be used.

In formula (10), M ² represents a metal of Group 13 to Group 15 of the periodic table, or a metalloid, and each R independently represents a hydrocarbon group having 1 to 12 carbon atoms or a substituted hydrocarbon group. , N represents the valence of the metal M2, and m represents an integer of 2 or more.

  (D) Another preferred example of the activator is an organoaluminum oxy compound containing a unit represented by the following formula (11).

  In formula (11), R shows a C1-C8 alkyl group, m shows the integer of 2-60.

  (D) A more preferred example of the activator is methylalumoxane containing a unit represented by the following formula (12).

  In formula (12), m shows the integer of 2-60.

Moreover, in the manufacturing method of the high-density polyethylene (A) in this embodiment, in addition to the supported geometrically constrained metallocene catalyst using the components (a) to (d), an organoaluminum compound is catalyzed as necessary. Can also be used.
Although it does not specifically limit as said organoaluminum compound, For example, the compound represented by following formula (13) is mentioned.

AlR _n X _3-n (13)

  In formula (13), R represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or an allyl group having 6 to 20 carbon atoms, X represents a halogen, hydrogen or alkoxyl group, n shows the integer of 1-3. The organoaluminum compound may be a mixture of compounds represented by formula (13).

The supported geometrically constrained metallocene catalyst described above can be obtained by supporting the component (a), the component (c), and the component (d) on the component (a) described above.
As a method of supporting component (a), component (c), and component (d), component (a) is added to a suspension in which component (a) is dispersed in an inert solvent, By stirring at 70 ° C. for 30 minutes or longer, the active hydrogen on the surface of the support material is reacted with the organoaluminum compound. Next, 20-50% by mass of the total charged amount is simultaneously added dropwise at 40-50 ° C. to the suspension of component (a) after reacting component (c) and component (d) with component (b). The remaining 50 to 80% by mass is preferably dropped simultaneously at 10 to 15 ° C. As a result, catalytic active sites can be formed inside the component (a), and by subjecting the catalyst to polymerization, polyethylene having high crystallinity tends to be generated inside the catalyst.

The component (c) and the component (d) are preferably liquid or solid.
In addition, component (a), component (c), and component (d) may be used after being diluted with an inert solvent during loading. Examples of the inert solvent include, but are not limited to, aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclohexane and methylcyclopentane; Aromatic hydrocarbons such as benzene, toluene and xylene; and mixtures thereof. The inert solvent is preferably used after removing impurities such as water, oxygen and sulfur using a desiccant, an adsorbent and the like.

The relative component (A) 1.0 g, the component (b) is preferably 1.0 × 10 ^-5 ~1.0 × 10 ^-1 mol in terms of Al atom, more preferably 1.0 × 10 ^{- 4 to} 5.0 × 10 ⁻² mol, and the component (c) is preferably 1.0 × 10 ^{−7 to} 1.0 × 10 ⁻³ mol, more preferably 5.0 × 10 ^{−7 to} 5.0. × 10 ⁻⁴ mol and component (d) are preferably 1.0 × 10 ^{−7 to} 1.0 × 10 ⁻³ mol, more preferably 5.0 × 10 ^{−7 to} 5.0 × 10 ⁻⁴ mol. Range.

The amount of each component used and the loading method are determined by activity, economy, powder characteristics, scale in the reactor, and the like. The obtained supported geometrically constrained metallocene catalyst was washed by a method such as decantation or filtration using an inert solvent for the purpose of removing organoaluminum compounds, borate compounds and titanium compounds not supported on the carrier. You can also
The series of operations such as dissolution, contact, and washing described above are preferably performed at a temperature of −30 ° C. or more and 80 ° C. or less selected for each unit operation. A more preferable range of such temperature is 0 ° C. or more and 50 ° C. or less. The series of operations for obtaining the supported geometrically constrained metallocene catalyst is preferably performed in a dry inert atmosphere.

The supported geometrically constrained metallocene catalyst alone can be used in the copolymerization process of ethylene and α-olefin in the production process of the high-density polyethylene (A) in the present embodiment. In order to prevent poisoning, an organoaluminum compound can be used together as the liquid promoter component (D).
Examples of the organoaluminum compound as the liquid promoter component (D) include, but are not limited to, alkyl aluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; diethylaluminum hydride, And alkylaluminum hydrides such as diisobutylaluminum hydride; aluminum alkoxides such as diethylaluminum ethoxide; and alumoxanes such as methylalumoxane, isobutylaluminoxane, and methylisobutylalumoxane. Among these, trialkylaluminum and aluminum alkoxide are preferable. More preferred is triisobutylaluminum.

The polymerization method in the production process of the high-density polyethylene (A) in this embodiment is preferably a slurry polymerization method. In the case of performing polymerization, generally, the polymerization pressure is preferably 0.1 MPa or more and 10 MPa or less, more preferably 0.3 MPa or more and 3.0 MPa or less.
The polymerization temperature is preferably 20 ° C. or higher and 115 ° C. or lower, more preferably 50 ° C. or higher and 85 ° C. or lower.
The solvent used in the slurry polymerization method is preferably an inert solvent used for dilution with an inert solvent used for diluting component (ii), component (c) and component (d) during the above-described loading, Inert hydrocarbon solvents are more preferred. Examples of the inert hydrocarbon solvent include hydrocarbon solvents having 6 to 8 carbon atoms, specifically, aliphatic hydrocarbons such as hexane, heptane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclopentane; Of the mixture.

  The polymerization method in the production process of the high-density polyethylene (A) in this embodiment is preferably a continuous polymerization. By continuously supplying ethylene gas, solvent, catalyst, etc. into the polymerization system and continuously discharging it together with the generated high-density polyethylene (A), partial high-temperature conditions due to rapid ethylene reaction can be suppressed. The polymerization system tends to become more stable. When ethylene reacts in a uniform state, the broadening of the molecular weight distribution tends to be suppressed.

  Also, when copolymerizing ethylene and α-olefin, after removing a certain amount of ethylene, hydrogen, and α-olefin in the flash tank after the polymerization vessel, keep the raw material in the buffer tank under the specified conditions. It is preferable to do. The lower limit of the temperature of the buffer tank is preferably 65 ° C. or higher, more preferably 68 ° C. or higher, and further preferably 70 ° C. or higher. Further, the upper limit of the temperature of the buffer tank is preferably 80 ° C. or less, and more preferably 75 ° C. or less. The flash tank is a facility that removes a certain amount of ethylene, hydrogen, and α-olefin by lowering the pressure from the polymerization vessel, but hydrogen with the smallest molecular weight is most easily removed, and it is removed in the order of ethylene and α-olefin. Ease changes. Therefore, the raw material composition in the flash tank is greatly changed from that in the polymerization vessel, and the concentrations of ethylene and α-olefin are relatively high. By being held in the buffer tank with its composition, unlike the polymerization vessel, the polymerization proceeds slowly in a state where the catalyst is not deactivated under the condition that the raw material concentration is low and the chain transfer agent concentration is low, There is a tendency that crystals having a uniform size are formed inside the high density polyethylene powder. Usually, the ethylene-α-olefin copolymer tends to decrease in crystallinity depending on the amount of α-olefin, but high crystallinity can be maintained by using the above production method.

  Examples of the solvent separation method in the method for producing high-density polyethylene (A) in the present embodiment include a decantation method, a centrifugal separation method, a filter filtration method, and the like, but the separation efficiency between the high-density polyethylene (A) and the solvent is high. High centrifugation is more preferred. The amount of the solvent contained in the high-density polyethylene (A) after the solvent separation is not particularly limited, but is preferably 50% by mass or more and 90% by mass or less, more preferably based on the mass of the high-density polyethylene (A). It is 55 mass% or more and 85 mass% or less, More preferably, it is 60 mass% or more and 80 mass% or less.

  As a deactivation method of the catalyst used for synthesizing the high density polyethylene (A), it is preferable to carry out after separating the high density polyethylene (A) and the solvent. Although it does not specifically limit as a chemical | medical agent which deactivates a catalyst, For example, oxygen, water, alcohols are mentioned.

The drying in the method for producing the high-density polyethylene (A) in the present embodiment is preferably performed in a state where an inert gas such as nitrogen or argon is circulated. Further, the drying temperature is preferably 50 ° C. or higher and 150 ° C. or lower, more preferably 50 ° C. or higher and 140 ° C. or lower, and further preferably 50 ° C. or higher and 130 ° C. or lower. If the drying temperature is 50 ° C. or higher, efficient drying tends to be possible. On the other hand, if the drying temperature is 150 ° C. or lower, it tends to be possible to dry in a state where decomposition and crosslinking of the high-density polyethylene (A) are suppressed.
In addition to the above-described components, other known components that are useful can be included in the production of the high-density polyethylene (A).

[High pressure low density polyethylene resin (B)]
The density (JIS K7112) of the high pressure method low density polyethylene resin (B) of this embodiment is preferably 910 to 930 kg / m ³ , more preferably 912 to 927 kg / m ³ , and even more preferably 915 to 925 kg. / M ³ When the density of the high-pressure method low-density polyethylene resin (B) is 910 kg / m ³ or more, an appropriate hardness can be maintained and a tearable film is obtained. Moreover, when the density of the high-pressure method low-density polyethylene resin (B) is 930 kg / m ³ or less, the melting point is kept moderate and the sealing performance can be maintained. The density of the high pressure method low density polyethylene (B) tends to decrease when the polymerization reaction peak temperature is increased, and tends to increase when the polymerization pressure is increased. Moreover, the density of the high-pressure method low-density polyethylene resin (B) can be measured by the method described in Examples.

  The 190 ° C., 2.16 kg melt flow rate (JIS K7210) of the high-pressure method low-density polyethylene resin (B) of the present embodiment is preferably 1 to 20 g / 10 minutes, more preferably 1.5 to 15 g / 10 minutes, more preferably 2 to 10 g / 10 minutes. When the MFR of the high-pressure method low-density polyethylene resin (B) is 1 g / 10 min or more, the drawdown property at the time of T-die molding can be maintained, and FE tends to be further suppressed. Moreover, it exists in the tendency which can suppress the neck-in at the time of T-die shaping | molding more because MFR of a high-pressure method low density polyethylene resin (B) is 20 g / 10min or less. The MFR of the high-pressure low-density polyethylene (B) tends to increase when the polymerization reaction peak temperature is increased, and tends to decrease when the polymerization pressure is increased. The melt flow rate of the high-pressure method low-density polyethylene resin (B) can be measured by the method described in the examples.

  The molecular weight distribution Mw / Mn of the high-pressure low-density polyethylene resin (B) of the present embodiment is preferably 2 to 30, more preferably 3 to 25, and still more preferably 5 to 20 from the viewpoint of processability. is there. The molecular weight distribution Mw / Mn of the high-pressure low-density polyethylene resin (B) can be controlled by the production conditions.

  The high-pressure low-density polyethylene (B) in this embodiment can be obtained by radical polymerization of ethylene in an autoclave type or tubular type reactor. When using an autoclave type reactor, the polymerization conditions may be set to, for example, a polymerization temperature of 200 to 300 ° C. and a polymerization pressure of 100 to 250 MPa in the presence of a peroxide acting as an initiator. On the other hand, when a tubular type reactor is used, the polymerization conditions are, for example, a polymerization temperature of 180 to 400 ° C., a polymerization of 100 to 400 MPa, preferably 200 to 350 ° C. in the presence of a peroxide and a chain transfer agent. What is necessary is just to set temperature and the superposition | polymerization pressure of 150-350 Mpa.

  Although it does not specifically limit as said peroxide, For example, methyl ethyl ketone peroxide, peroxyketals (specifically, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1, 1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valate, 2,2-bis (t -Butylperoxy) butane, etc.), hydroperoxides (specifically, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3, 3-tetramethylbutyl hydroperoxide, etc.), dialkyl peroxides ( Specifically, di-t-butyl peroxide, dicumyl peroxide, bis (t-butylperoxyisopropyl) benzene, t-butylcumyl peroxide, 2,5-di (t-butylperoxy) hexane, 2,5-dimethyldi (t-butylperoxy) hexane), diacyl peroxide (specifically, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide) Benzoyl peroxide), peroxydicarbonates (specifically, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxycarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethylperoxide) Oxycarbonate, dimethoxy Isopropyl peroxydicarbonate, dimethoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl peroxydicarbonate, diallyl peroxydicarbonate, etc.), peroxyesters (specifically, t-butylperoxydicarbonate) Oxyacetate, t-butylperoxyisobutyrate, t-butylperoxypivalate, t-butylperoxyoctate, t-butylperoxyneodecanoate, t-butylperoxyneodecanoate, cumylper Oxyneodecanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-3,5,6-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate , T-Butylperoxyisopropyl Carbonate, cumylperoxyoctoate, t-hexylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxyneohexanoate, t-hexylperoxyneohexanoate, cumylperoxyneo Hexanoate, etc.), acetylcyclohexylsulfonyl peroxide, t-butylperoxyallyl carbonate and the like.

The peroxide is preferably fed to the polymerization reactor in a state diluted with an isoparaffin solvent, and the concentration of the peroxide is preferably 5% by mass or more and 35% by mass or less. The isoparaffinic solvent is not particularly limited. For example, a solvent having 10 to 15 carbon atoms is preferable, and specifically, isodecane, isoundecane, isododecane, and the like are preferable. By diluting and feeding in an isoparaffin solvent, isoparaffin, which can be a chain transfer agent, is added into the polymerization system in contact with the initiator peroxide at a high concentration. This is likely to occur. Furthermore, the peroxide tends to cause a long-chain branching start point by using two or more different starting temperatures in combination. When the long chain branching is increased, the molding process is stabilized and the dispersion state with the high density polyethylene is improved, which contributes to the improvement of the tearability.
Although it does not specifically limit as a chain transfer agent for molecular weight adjustment, For example, C3-C6 paraffin, an olefin, and ketones are mentioned, Specifically, propane, butane, isobutane, pentane, Examples include isopentane, hexane, isohexane, propylene, butene, pentene, hexene, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, and dipropyl ketone.

  Hereinafter, the present embodiment will be described in more detail based on examples, but the present embodiment is not limited to the following examples. First, the physical properties and measurement methods for evaluation and evaluation criteria will be described below.

(Physical property 1) MFR
The MFR of the polyethylene obtained in the production example was measured at 190 ° C. under a load of 2.16 kg according to ASTM-D-1238.

(Physical property 2) Density The density of the polyethylene obtained in the production example was measured by a density gradient tube method in accordance with JIS K6760.

(Physical property 3) TREF (temperature rising elution fractionation method) measurement About the polyethylene composition manufactured by the Example and the comparative example, the elution temperature-elution amount curve by TREF (temperature rising elution fractionation method) measurement was measured as follows, The amount of elution at each temperature, the integrated amount of elution, and the weight fraction Wmax of the maximum elution amount, and the weight fraction W1 of the local maximum elution amount between 60 ° C. and 80 ° C. were determined.
First, a sample solution in which 20 mg of a polyethylene composition was dissolved in 0.5 ml of orthodichlorobenzene was prepared and introduced into the sample chamber. Thereafter, the temperature of the sample chamber was raised from room temperature to 140 ° C. at 40 ° C./min and held for 120 minutes. Next, the temperature of the sample chamber was lowered to 40 ° C. at a temperature drop rate of 0.5 ° C./min, and then held for 20 minutes to deposit the sample on the surface of the filler in the sample chamber.
Thereafter, the temperature of the sample chamber and the column was sequentially increased from 40 ° C. to 120 ° C. at a temperature increase rate of 20 ° C./min. At the time of temperature increase, each temperature was maintained at the corresponding temperature for 21 minutes, and then the temperature was increased to the next temperature. The concentration of the sample (polyethylene composition) eluted at each temperature was detected. And the elution temperature-elution amount curve is measured from the value of the elution amount weight fraction (mass%) of the sample (polyethylene composition) and the temperature in the column (° C.) at that time, and the elution amount at each temperature Asked.

The measurement conditions were as follows.
-Apparatus: Automated 3D analyzer CFC-2 manufactured by Polymer ChAR
Column: Stainless steel microball column (outer diameter 3/8 inch, length 150 mm)
Eluent: o-dichlorobenzene (for high performance liquid chromatograph)
Sample solution concentration: Sample (ethylene polymer) 20 mg / o-dichlorobenzene 0.5 mL
・ Injection volume: 0.5 mL
Pump flow rate: 1.0 mL / min Detector: Infrared spectrophotometer IR4 manufactured by Polymer ChAR
・ Detected wave number: 3.42 μm
-Sample dissolution conditions: 140 ° C x 120 minutes

(Physical property 4) 1/2 isothermal crystallization time (DSC measurement)
1/2 isothermal crystallization time (DSC measurement) is 8 to 9 mg of sample, and after measuring the extrapolation crystallization start temperature using DSC8000 manufactured by PERKIN ELMER, isothermal crystallization is performed at a temperature 1 ° C. higher than the temperature. The value was measured.

1. Measurement of extrapolation crystal start temperature The extrapolation crystal start point was measured according to the following procedure.
・ Temperature profile (1) Hold at 50 ° C for 1 minute (2) Temperature rise from 50 ° C to 180 ° C at 200 ° C / minute (3) Hold at 180 ° C for 5 minutes (4) 180 ° C to 50 ° C at 10 ° C / minute The temperature drop and extrapolation crystallization start temperature were calculated from the above results by a method according to JIS K7121.

2. 1/2 Isothermal Crystallization 1/2 isothermal crystallization time was measured according to the following procedure.
Measurement procedure (1) Hold at 50 ° C for 1 minute (2) Temperature rise from 50 ° C to 180 ° C at 200 ° C / minute (3) Hold at 180 ° C for 5 minutes (4) Extrapolation from 180 ° C at 80 ° C / minute Decrease in temperature to crystallization temperature + 1 ° C (5) Hold for 5 minutes at extrapolation crystallization temperature + 1 ° C (6) Define the time at which the exothermic curve peaks as 1/2 isothermal crystallization time

(Physical property 5) Elmendorf tear strength Using a polyethylene resin composition, a Hokushin φ40 mm extruder (screw diameter 40 mm, die 300 mm width, lip opening 0.6 mm), cylinder temperature 230 ° C., die temperature 230 ° C., extrusion amount 10 kg A film made of a polyethylene resin having a width of 25 cm and a thickness of 35 μm was formed. The thickness of the obtained film was measured, and the tear strength was measured according to JIS K7128-2. The tear strength obtained was converted per 1 cm thickness.

(Physical property 6) Hand cutting property About the hand cutting property, the film was torn in the MD direction by hand and evaluated according to the following criteria.
◯: A film that was torn straight was considered good.
Δ: A film that was torn while being zigzag was made slightly good.
X: A film that could not be torn straight and was torn obliquely was regarded as defective.

(Physical property 7) Coating property The film formed in the above (Physical property 5) was cut into a 20 cm × 20 cm square, placed on a flat plate after corona treatment. A 5% solution of Chukyo Yushi Resem P-677 (non-silicone mold release agent) was applied to the film with a wire bar (No. 50). When the area where the solution was repelled from the film surface on the coated film surface was less than 1%, it was rated as ◎, when it was 1-5%, it was rated as Δ, and when it was larger than 5%, x It was evaluated.

(Physical Property 8) Sealing Property The sealing property was evaluated by extrusion laminating the polyethylene resin composition on a 20 μm aluminum thin film, and measuring the sealing property of the obtained film with a tensile tester.
Extrusion laminating method: A uniaxial extruder equipped with a straight manifold type as a die was used, and the lip width was set to 400 mm and the lip clearance was set to 0.7 mm. The resin was extruded at a resin temperature of 310 ° C., and laminated on an aluminum foil fed from a feeding machine through an air gap of 140 mm. Then, it cooled with the semi-mirror specification cooling roll, and wound up the laminate film on the winder.
Heat seal strength: The laminated film obtained by the above extrusion laminating method was heat sealed using a heat sealer (manufactured by Tester Sangyo Co., Ltd.) at a seal temperature of 100 ° C., a seal pressure of 2 kg / cm ² , and a seal time of 1 second. The peel strength of the seal portion was measured using a tensile tester (manufactured by Orientec Co., Ltd.) under conditions of a tensile speed of 300 mm / min.
When the heat seal strength was larger than 4N / 15 mm, it was judged as good, when it was 3-4N / 15 mm, it was good, and when it was less than 3N, it was judged as bad.

(Physical property 9) Chlorine content measurement method About 0.05 g of each polyethylene resin composition obtained in the examples and comparative examples is put in a quartz boat and burned with an automatic combustion apparatus AQF-100 manufactured by Mitsubishi Analitech Co., Ltd. It was. The generated combustion gas was absorbed in an absorption solution to which tartaric acid had been added in advance, and the chlorine content was quantified by an internal standard method using tartaric acid as an internal standard substance with an ion chromatograph analyzer ICS-1500 manufactured by Dionex. The unit was ppm by mass.

  In Examples and Comparative Examples, resin materials produced by the following method were used.

[Preparation of catalyst]
(1) Preparation of supported geometrically constrained metallocene catalyst [A] Silica for catalyst carrier (average particle size 15 μm, compressive strength 3 MPa) dehydrated at 600 ° C. in a nitrogen atmosphere in a 1.8 L autoclave And dispersed in 800 mL of hexane to obtain a slurry. The obtained slurry was kept at 25 ° C., and 84 mL of a hexane solution of triethylaluminum (concentration 1 mol / L) was added while stirring. Thereafter, the mixture was stirred for 2 hours to react triethylaluminum with the surface hydroxyl group of silica to obtain a hexane slurry of component [a1] in which the surface hydroxyl group of silica was capped with triethylaluminum.
On the other hand, 200 mmol of [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium dimethyl (hereinafter referred to as “titanium complex”) was added to Isopar E (registered trademark) (Exxon Chemical Co., Ltd.). (US) Hydrocarbon mixture trade name) Dissolved in 1000 mL, added 20 mL of 1 mol / L hexane solution of n-butylethylmagnesium, further added hexane to adjust the titanium complex concentration to 0.1 mol / L, Component [b1] was obtained.
Further, 5.7 g of bis (hydrogenated tallow alkyl) methylammonium-tris (pentafluorophenyl) (4-hydroxyphenyl) borate (hereinafter referred to as “borate compound”) was added to 50 mL of toluene and dissolved, A 100 mmol / L toluene solution of the borate compound was obtained. To the toluene solution of the borate compound, 5 mL of a 1 mol / L hexane solution of diethylaluminum ethoxide was added at room temperature, and further hexane was added so that the borate compound concentration in the solution was 70 mmol / L. Then, it stirred at room temperature for 1 hour and obtained reaction mixture [c] containing a borate compound.
After raising the temperature of the [a1] slurry to 45 to 50 ° C., the stirring speed was 600 rpm, and 9.2 mL of [c] and [6.4] of [b1] were simultaneously added dropwise to the [a1] slurry over 20 minutes. Then, the catalyst active species were infiltrated into the silica by stirring at 50 ° C. for 1 hour. Thereafter, the supernatant containing the unreacted borate compound / titanium complex in the obtained reaction mixture was removed by decantation, whereby the catalytically active species were supported inside the silica. Further, after the temperature was lowered to 10 to 15 ° C., 36.8 mL of [c] and 25.6 mL of [b1] were simultaneously added dropwise over 80 minutes, and then stirred at 15 to 20 ° C. for 3 hours, whereby the titanium complex and borate Was reacted and precipitated to physically adsorb the catalytically active species on the silica surface. Thereafter, the supernatant containing the unreacted borate compound / titanium complex in the obtained reaction mixture is removed by decantation, whereby the supported geometrically constrained metallocene in which the catalytically active species are formed on the silica surface and inside is obtained. A catalyst [A] (simply indicated as [A] in [Preparation of polyethylene] described later) was obtained.

(2) Preparation of supported geometrically constrained metallocene catalyst [B] Silica for catalyst carrier (average particle size 15 μm, compressive strength 35 MPa) dehydrated at 500 ° C. in an autoclave having a capacity of 1.8 L under a nitrogen atmosphere. 40 g of this dehydrated silica was dispersed in 800 mL of hexane to obtain a slurry. While maintaining the resulting slurry at 25 ° C. with stirring, 84 mL of a hexane solution of triethylaluminum (concentration: 1 mol / L) was added, and then stirred for 2 hours to react triethylaluminum with the surface hydroxyl group of silica to obtain the surface hydroxyl group of silica. A hexane slurry of component [a2] capped with triethylaluminum was obtained.
On the other hand, 200 mmol of [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium dimethyl (hereinafter referred to as “titanium complex”) was added to Isopar E (registered trademark) (Exxon Chemical Co., Ltd.). (US) Hydrocarbon mixture trade name) 1 mol / L hexane solution of AlMg ₆ (C ₂ H ₅ ) ₃ (n-C ₄ H ₉ ) ₁₂ dissolved in 1000 mL and previously synthesized from triethylaluminum and dibutylmagnesium 20 mL, and further hexane was added to adjust the titanium complex concentration to 0.1 mol / L to obtain a component [b2] slurry.
After the temperature of the above component [a2] slurry was raised to 20 to 25 ° C., the stirring rotation speed was 300 rpm, and 46 mL of the reaction mixture [c] containing the borate compound in (1) and 32 mL of [b2] were added to the [a2] slurry. The solution was added dropwise over a period of time and stirred for another 3 hours to allow the titanium complex and borate to react and precipitate, thereby physically adsorbing the catalytically active species on the silica surface. Thereafter, the supernatant containing the unreacted borate compound / titanium complex in the obtained reaction mixture is removed by decantation, whereby the supported geometrically constrained metallocene catalyst in which the catalytically active species is formed on the silica surface [ B] (simply referred to as [B] in [Preparation of polyethylene] described later).

(3) Preparation of Ziegler-Natta catalyst [C] 1) Synthesis of carrier A 1 mL of 2 mol / L hexane solution of trichlorosilane was charged in a fully nitrogen-substituted 8 L stainless steel autoclave and stirred at 65 ° C for AlMg. ₅ 550 mL (equivalent to 2.68 mol of magnesium) of a hexane solution of an organomagnesium compound represented by ₅ (C ₄ H ₉ ) ₁₁ (OC ₄ H ₉ ) ₂ was added dropwise over 4 hours, and the mixture was further stirred at 65 ° C. for 1 hour. The reaction was continued while. After completion of the reaction, the supernatant was removed and washed 4 times with 1,800 mL of hexane. As a result of analyzing this solid, magnesium contained per gram of the solid was 8.31 mmol.
2) Preparation of Ziegler-Natta catalyst [C] While stirring at 10 ° C. to 1,970 mL of hexane slurry containing 110 g of the above carrier, 110 mL of 1 mol / L titanium tetrachloride hexane solution and 1.0 mol / L AlMg ₅ (C 110 mL of a hexane solution of an organomagnesium compound represented by ₄ H ₉ ) ₁₁ (OSiH) ₂ was simultaneously added over 1 hour. After the addition, the reaction was continued for 1 hour at 10 ° C. After completion of the reaction, the supernatant liquid is removed by decantation and washed twice with hexane, so that it is simply indicated as [C] in the Ziegler-Natta catalyst [C] (preparation of polyethylene described later) as a solid catalyst component. ) Was prepared.

[Preparation of polyethylene]
(1) High density polyethylene (A)
[Production of high-density polyethylene (A-1)]
High density polyethylene was obtained by the continuous slurry polymerization method shown below. Specifically, continuous polymerization was performed using a Bessel type 340L polymerization reactor equipped with a stirrer under conditions of a polymerization temperature of 80 ° C., a polymerization pressure of 0.98 MPa, and an average residence time of 3.2 hours. The polymerization rate was 10 kg / hour, dehydrated normal hexane 40 L / hour as a solvent, [A] as a catalyst at 1.4 mmol / hour in terms of Ti atom, and triisobutylaluminum as a liquid promoter component at 20 mmol / hour. In addition, hydrogen for molecular weight adjustment is supplied at 0.25 mol% with respect to the gas phase concentration of ethylene and 1-butene, and 1-butene is supplied at 0.37 mol% with respect to the gas phase concentration of ethylene. Ethylene and 1-butene were copolymerized. The slurry concentration was 27% by weight. The catalyst was supplied from near the liquid level of the polymerization vessel, and ethylene and 1-butene were supplied from the bottom of the polymerization vessel. The polymerization slurry in the polymerization reactor is led to a flash tank with a pressure of 0.05 MPa and a temperature of 70 ° C. so that the level of the polymerization reactor is kept constant, and a certain amount of unreacted ethylene, 1-butene and hydrogen are separated. did. Thereafter, the sample was introduced into a buffer tank having a pressure of 0.30 MPa and a temperature of 65 ° C. under an average residence time of 1.0 hour. Next, the slurry was continuously sent to a centrifuge so that the level of the buffer tank was kept constant, and the powder and other solvents were separated. The separated high density polyethylene powder was dried at 85 ° C. while blowing nitrogen. In this drying step, the catalyst and the cocatalyst were deactivated by spraying steam on the powder.
The obtained high-density polyethylene powder was used without using additives such as a neutralizing agent and an antioxidant, and was manufactured by Nippon Steel Works TEX-44 (screw diameter 44 mm, L / D = 35. L: raw material supply port Using a twin-screw extruder with a distance from the outlet to the outlet (m), D: inside diameter (m)), and melt-kneaded at a temperature of 200 ° C. with an extrusion rate of 30 kg / hour. It was used and cut and granulated under the conditions of 12 cutter blades and 550 rpm to obtain high-density polyethylene (A-1). The average weight of one pellet was 18.5 mg. Table 1 shows the evaluation results of MFR and density of the high-density polyethylene (A-1).

[Production of high-density polyethylene (A-2)]
A high density polyethylene (A--) was used except that hydrogen was supplied at 0.32 mol% with respect to the gas phase concentration of ethylene and 1-butene, and 1-butene was supplied at 0.21 mol% with respect to the gas phase concentration of ethylene. High density polyethylene (A-2) was obtained by the same operation as in the production of 1). The average weight of one pellet was 17.5 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-3)]
A high density polyethylene (A--) was used except that hydrogen was supplied at 0.56 mol% with respect to the gas phase concentration of ethylene and 1-butene and 1-butene was supplied at 0.06 mol% with respect to the gas phase concentration of ethylene. High density polyethylene (A-3) was obtained by the same operation as in the production of 1). The average weight of one pellet was 18.0 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-4)]
The production of high density polyethylene (A-1) except that hydrogen was supplied to 0.47 mol% with respect to the gas phase concentration of ethylene, 1-butene was not supplied, and the buffer tank was not used. High density polyethylene (A-4) was obtained by the same operation. The average weight of one pellet was 17.7 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-5)]
The production of high-density polyethylene (A-1) except that hydrogen was supplied at 0.17 mol% with respect to the gas phase concentration of ethylene, 1-butene was not supplied, and no buffer tank was used. High density polyethylene (A-4) was obtained by the same operation. The average weight of one pellet was 18.3 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-6)]
The polymerization temperature is 83 ° C., the polymerization pressure is 0.80 MPa, [C] is used as a catalyst, hydrogen is 44.33 mol% with respect to the vapor phase concentration of ethylene and 1-butene, and 1-butene is vapor phase concentration of ethylene. The polymer was polymerized by the same operation as in the production of high density polyethylene (A-1) except that the buffer tank was not used, and a high density polyethylene powder was obtained. The resulting high density polyethylene powder was high density except that 300 mass ppm of pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was added as an antioxidant. Granulation was performed in the same manner as in the production of polyethylene (A-1) to obtain high-density polyethylene (A-6). The average weight of one pellet was 16.0 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-7)]
Operation similar to the production of high-density polyethylene (A-6) except that the polymerization temperature was 85 ° C., the polymerization pressure was 1.0 MPa, hydrogen was 64 mol% with respect to the gas phase concentration of ethylene, and 1-butene was not supplied. As a result, high-density polyethylene (A-7) was obtained. The average weight of one pellet was 17.2 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-8)]
High density except that the polymerization temperature is 85 ° C., the polymerization pressure is 0.95 MPa, hydrogen is 27.5 mol% with respect to the gas phase concentration of ethylene and propylene, and propylene is 3.3 mol% with respect to the gas phase concentration of ethylene. High density polyethylene (A-8) was obtained by the same operation as in the production of polyethylene (A-6). The average weight of one pellet was 16.5 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-9)]
Except for setting the polymerization temperature to 85 ° C., the polymerization pressure to 0.95 MPa, hydrogen to 58 mol% with respect to the gas phase concentration of ethylene and propylene, and propylene to 1.6 mol% with respect to the gas phase concentration of ethylene, high density polyethylene ( High density polyethylene (A-9) was obtained by the same operation as in the production of A-6). The average weight of one pellet was 19.0 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-10)]
A polymerization temperature of 75 ° C., a polymerization pressure of 0.8 MPa, an average residence time of 1.6 hours, [B] is used as a catalyst, and hydrogen for molecular weight adjustment is 0.21 mol relative to the gas phase concentration of ethylene and 1-butene. % And 1-butene were supplied so as to be 0.27 mol% with respect to the gas phase concentration of ethylene, thereby polymerizing ethylene and 1-butene. In addition, dehydrated normal hexane is supplied from the bottom of the polymerization vessel, hydrogen is supplied from the catalyst introduction line together with the catalyst in advance for contact with the catalyst, and ethylene is supplied from the middle between the liquid level and the bottom of the polymerization vessel, and ethylene is supplied from the bottom of the polymerization vessel. Supplied. The polymerization slurry in the polymerization reactor was led to a flash tank having a pressure of 0.08 MPa and a temperature of 75 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene, 1-butene and hydrogen were separated.
Next, the polymerization slurry was continuously sent to a centrifuge so that the level of the polymerization reactor was kept constant, and the polymer and other solvents were separated.
The separated high density polyethylene powder was dried at 85 ° C. while blowing nitrogen. In this drying step, the catalyst and the cocatalyst were deactivated by spraying steam on the polymerized powder.
The obtained high-density polyethylene powder was granulated by the same operation as high-density polyethylene (A-1) to obtain high-density polyethylene (A-10). The average weight of one pellet was 17.9 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-11)]
A high density polyethylene (A--) was used except that hydrogen was supplied at 0.12 mol% with respect to the gas phase concentration of ethylene and 1-butene, and 1-butene was supplied at 0.011 mol% with respect to the gas phase concentration of ethylene. High density polyethylene (A-11) was obtained by the same operation as in the production of 10). The average weight of one pellet was 17.5 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-density polyethylene (A-12)]
Operation similar to the production of high density polyethylene (A-6) except that the polymerization temperature is 86 ° C., the polymerization pressure is 1.0 MPa, hydrogen is 46 mol% with respect to the gas phase concentration of ethylene, and 1-butene is not supplied. As a result, high-density polyethylene (A-12) was obtained. The average weight of one pellet was 19.3 mg. Table 1 shows the evaluation results of MFR and density.

(2) High pressure low density polyethylene (B)
[Production of high-pressure low-density polyethylene (B-1)]
In an autoclave reactor, a polymerization temperature of 256 ° C., a polymerization pressure of 168 MPa, and t-butyl peracetate and t-butyl peroctate diluted as isododecane at a molar ratio of 2: 8 to 11% by mass are used. , After feeding ethylene isobutane as a chain transfer agent to 1.85 mol% with respect to ethylene and polymerizing ethylene, the mixture was melt kneaded at a temperature of 180 ° C. with an extrusion rate of 50 kg / hour, Using a strand cutter made by TOSHIBA MACHINE, cutting was performed under the conditions of 16 cutter blades and 700 rpm, and granulated to obtain a high-pressure low-density polyethylene resin. The average weight of one pellet was 17.5 mg. Table 1 shows the evaluation results of MFR and density of the obtained high-pressure low-density polyethylene resin (B-1).

[Production of high-pressure low-density polyethylene (B-2)]
In a tubular reactor, an average polymerization temperature of 305 ° C., a polymerization pressure of 191 MPa, di-t-butyl peroxide as an initiator is used undiluted, and propylene as a chain transfer agent is 0.3 mol% with respect to ethylene. The high pressure method low density polyethylene (B-2) was obtained by operation similar to manufacture of the high pressure method low density polyethylene (B-1) except having performed. The average weight of one pellet was 17.5 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-3)]
In an autoclave reactor, the polymerization temperature was 256 ° C., the polymerization pressure was 168 MPa, and t-butyl peracetate was used as an initiator undiluted. A method low density polyethylene (B-3) was obtained. The average weight of one pellet was 21.3 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-4)]
In an autoclave reactor, a polymerization temperature of 258 ° C., a polymerization pressure of 120 MPa, and t-butyl peracetate and t-butyl peroctate diluted as isododecane in a molar ratio of 1: 9 to 25% by mass are used. Except for the above, high pressure method low density polyethylene (B-4) was obtained by the same operation as the production of high pressure method low density polyethylene (B-1). The average weight of one pellet was 18.6 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-5)]
In an autoclave reactor, a polymerization temperature of 190 ° C., a polymerization pressure of 126 MPa, and t-butyl peroxybivalate and t-butyl peracetate as initiators diluted with isododecane in a molar ratio of 7: 3 to 25% by mass. A high-pressure method low-density polyethylene (B-5) was obtained by the same operation as in the production of the high-pressure method low-density polyethylene (B-1) except that it was used. The average weight of one pellet was 16.5 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-6)]
In an autoclave reactor, the polymerization temperature was 183 ° C., the polymerization pressure was 191 MPa, and t-butyl peroxybivalate and t-butyl peroctate were diluted as initiators in a molar ratio of 5: 5 to 13% by mass in isododecane. The high-pressure low-density polyethylene (B) was prepared in the same manner as in the production of the high-pressure low-density polyethylene (B-1) except that methyl ethyl ketone was 0.71 mol% with respect to ethylene as a chain transfer agent. -6) was obtained. The average weight of one pellet was 18.7 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-7)]
In an autoclave reactor, a polymerization temperature of 230 ° C., a polymerization pressure of 201 MPa, and t-butyl peroctate and t-butyl peracetate diluted as isododecane at a molar ratio of 6: 4 to 10% by mass are used. The high pressure method low density polyethylene (B-7) was prepared in the same manner as in the production of the high pressure method low density polyethylene (B-1) except that isobutane was 3.85 mol% with respect to ethylene as the chain transfer agent. ) The average weight of one pellet was 18.0 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure method low-density polyethylene (B-8)]
In a tubular reactor, a polymerization temperature of 300 ° C., a polymerization pressure of 255 MPa, di-t-butyl peroxide as an initiator was used undiluted, and propylene as a chain transfer agent was adjusted to 1.1 mol% with respect to ethylene. Except for the above, a high pressure method low density polyethylene (B-8) was obtained by the same operation as in the production of the high pressure method low density polyethylene (B-1). The average weight of one pellet was 18.0 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-9)]
In a tubular reactor, chain transfer using an average polymerization temperature of 285 ° C., a polymerization pressure of 265 MPa, and di-t-butyl peroxide and t-butyl peroctate diluted to isododecane at a molar ratio of 4: 6 as initiators. The high pressure method low density polyethylene (B-9) was obtained by the same operation as the production of the high pressure method low density polyethylene (B-1) except that propylene was adjusted to 1.0 mol% with respect to ethylene. It was. The average weight of one pellet was 16.9 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure method low-density polyethylene (B-10)]
In an autoclave reactor, a polymerization temperature of 256 ° C., a polymerization pressure of 122 MPa, and t-butyl peracetate and t-butyl peroctate diluted as isododecane at a molar ratio of 1: 9 to 30% by mass are used. A high pressure method low density polyethylene (B-10) was obtained in the same manner as in the production of the high pressure method low density polyethylene (B-1) except that the above method was used. The average weight of one pellet was 17.3 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure low-density polyethylene (B-11)]
In an autoclave reactor, a polymerization temperature of 208 ° C., a polymerization pressure of 112 MPa, and t-butyl peroxybivalate and t-butyl peroctate as an initiator diluted at a molar ratio of 5: 5 to 30% by mass in isododecane A high-pressure low-density polyethylene (B-11) was obtained by the same operation as in the production of the high-pressure low-density polyethylene (B-1) except that was used. The average weight of one pellet was 18.6 mg. Table 1 shows the evaluation results of MFR and density.

[Production of high-pressure method low-density polyethylene (B-12)]
In an autoclave reactor, except that the polymerization temperature was 245 ° C., the polymerization pressure was 170 MPa, and t-butyl peroxyacetate was used as an initiator without dilution, the same operation as in the production of the high-pressure method low-density polyethylene (B-1), High pressure method low density polyethylene (B-12) was obtained. The average weight of one pellet was 15.3 mg. Table 1 shows the evaluation results of MFR and density.

(3) Polyethylene resin composition [Example 1]
A-1 is used as the high-density polyethylene resin, B-7 is used as the high-pressure method low-density polyethylene resin, and a single screw extruder (screw diameter 65 mm, L / D = 28) manufactured by Nippon Steel Co., Ltd. is used. Performed by melt kneading at an extrusion rate of 30 kg / hour and 200 ° C. so that 1 and B-7 are 40% by mass and 60% by mass, respectively, and cutting and granulating under the conditions of 12 cutter blades and 600 rpm. The polyethylene resin composition PE-1 was obtained. The evaluation results are shown in Table 1.

[Example 2]
A polyethylene resin composition PE-2 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1 except that A-2 and B-9 were 45% by mass and 55% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 3]
A polyethylene resin composition PE-3 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-3 and B-1 were 50% by mass and 50% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 4]
A polyethylene resin composition PE-4 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-4 and B-1 were 60% by mass and 40% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 5]
A polyethylene resin composition PE-5 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-5 and B-4 were 80% by mass and 20% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 6]
A polyethylene resin composition PE-6 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-2 and B-5 were 70% by mass and 30% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 7]
A polyethylene resin composition PE-7 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-3 and B-6 were 80% by mass and 20% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 8]
A polyethylene resin composition PE-8 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-4 and B-10 were 80% by mass and 20% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Example 9]
A polyethylene resin composition PE-9 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-5 and B-11 were 30% by mass and 70% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 1]
A polyethylene resin composition PE-10 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-6 and B-1 were 54% by mass and 46% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 2]
A polyethylene resin composition PE-11 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-7 and B-2 were 45% by mass and 55% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 3]
A polyethylene resin composition PE-12 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-8 and B-8 were 80% by mass and 20% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 4]
A polyethylene resin composition PE-13 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-9 and B-3 were 20% by mass and 80% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 5]
A polyethylene resin composition PE-14 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-10 and B-12 were 50% by mass and 50% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 6]
A polyethylene resin composition PE-15 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-11 and B-12 were 60% by mass and 40% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 7]
A polyethylene resin composition PE-16 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-12 and B-1 were 20% by mass and 80% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 8]
A polyethylene resin composition PE-17 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-6 and B-1 were 80% by mass and 20% by mass, respectively. Obtained. The evaluation results are shown in Table 1.

[Comparative Example 9]
A polyethylene resin composition PE-17 was prepared in the same manner as in the production of the polyethylene resin composition PE-1 of Example 1, except that A-3 and B-12 were 50% by mass and 50% by mass, respectively. Obtained. The evaluation results are shown in Table 1. The difference in weight between the pellets of high-density polyethylene and high-pressure low-density polyethylene is large and the particle size is not uniform. It was low.

  Since the polyethylene resin composition of the present invention is excellent in tearability, hand cutting property and high cleanliness, it can be used as a base material for food, easy-to-cut packaging materials for pharmaceuticals, and adhesive tape that can be cut in the horizontal direction by hand. It can be used as a packaging material for rice balls, especially for applications that take advantage of easy-cutting and cleanliness (non-contamination). Furthermore, since the chlorine content is extremely small, it can also be used as a packaging material for electronic parts such as semiconductors and parts transport trays that are not susceptible to malfunction due to adhesion of chlorine atoms.

Claims (7)

A polyethylene resin composition having a density of 930 to 960 kg / m ³ , a melt flow rate at 190 ° C. and 2.16 kg of 1 to 20 g / 10 minutes,
When TREF (Temperature Elution Fractionation) measurement is performed using a CFC device under the following conditions, one or more elution temperature-elution amount curve peaks appear at 80 ° C or lower, and at least one at 90 ° C or higher. A polyethylene resin composition in which the peak of the maximum amount (Wmax) appears at 90 ° C. or more, and the maximum value is 10% by weight or more of the total elution amount.
(1) Weigh 20 mg of the polyethylene resin composition and inject 0.5 ml of o-dichlorobenzene;
(2) Hold at 140 ° C. for 120 minutes to completely dissolve the polyethylene resin composition, and introduce the solution into a TREF column;
(3) The temperature is decreased from 140 ° C. to 40 ° C. at 0.5 ° C./min, and deposited on the column, and then held at 40 ° C. for 20 minutes;
(4) Raise the temperature by 1 ° C from 40 ° C to 140 ° C, hold the temperature for 15 minutes or more after raising the temperature at each temperature, perform TREF measurement, and measure the elution amount   2. The polyethylene resin according to claim 1, wherein a ratio between the maximum value (Wmax) of the elution amount and the maximum elution amount (W1) at an elution temperature of 60 to 80 ° C. in TREF measurement, Wmax / W1 is 2.0 or more. Composition.   The polyethylene resin composition of Claim 1 or 2 comprised from 30-80 mass% of high density polyethylene resins (A) and 20-70 mass% of high-pressure method low density polyethylene resins (B).   In DSC measurement, ½ isothermal crystallization time when melted at 180 ° C. for 5 minutes and measured at 1 ° C. above the extrapolation crystallization start temperature (Tic) under the condition of a temperature drop rate of 80 ° C./min. The polyethylene resin composition in any one of Claims 1-3 which is 0.7 minutes or more.   The polyethylene resin composition according to claim 3 or 4, wherein the high-density polyethylene resin (A) is an ethylene homopolymer, an ethylene-propylene copolymer, or an ethylene-butene copolymer.   The high-density polyethylene resin (A) comprises (a) a carrier material; (b) an organoaluminum compound; (c) a transition metal compound having a cyclic η-bonding anion ligand; and (d) the cyclic η-bonding anion coordination. Polymerization using a supported metallocene catalyst (C) prepared from an activator capable of forming a complex that exhibits catalytic activity by reacting with a transition metal compound having a child, and a liquid promoter component (D) The polyethylene resin composition in any one of Claims 3-5 which is manufactured by this.   The polyethylene resin composition according to any one of claims 1 to 6, wherein a chlorine atom content is 2.0 mass ppm or less with respect to the polyethylene resin composition.