High-density polyethylene composition, high-density polyethylene material, and preparation method and application of high-density polyethylene material

Abstract

The invention discloses a high-density polyethylene composition, a high-density polyethylene material as well as a preparation method and application of the high-density polyethylene material. The high-density polyethylene composition comprises ethylene / hexene-1 copolymer resin and a metallic soap stabilizer, wherein the weight ratio of the ethylene / hexene-1 copolymer resin to the metallic soap stabilizer is 100: (0.1-0.3); wherein the melt flow rate of the ethylene / hexene-1 copolymer resin is 12-18g / 10min, the density is 0.95-0.955 g / cm < 3 >, the weight-average molecular weight is 160000-220000, and the molecular weight distribution is 12-17. The high-density polyethylene material prepared from the high-density polyethylene composition has excellent rigidity-toughness balance performance and can be used for preparing a medical hollow blow molding material.

Description

Technical Field

[0001] This invention relates to the field of blow molding materials technology, specifically to high-density polyethylene compositions, high-density polyethylene materials, their preparation methods, and applications. Background Technology

[0002] As a crucial component of dialysis treatment, hemodialysis fluid containers require high safety and reliability. Traditionally, these containers are made of polyvinyl chloride (PVC), which has limitations in chemical resistance, high-temperature resistance, and impact resistance. To improve the overall performance of hemodialysis fluid containers and meet clinical needs, there is an urgent need for the market to provide a medical-grade hollow blow-molded material that offers a balance of rigidity and toughness, and is environmentally friendly and safe.

[0003] High-density polyethylene (HDPE), with its advantages of high molecular weight, good thermal stability, corrosion resistance, and ease of processing, has become the most widely used raw material resin for blow molding products. Its products have been applied in many packaging fields, including food, chemical, agricultural, and horticultural industries. However, dialysis fluid contains various chemical substances, such as acids, alkalis, and various inorganic salts. Under certain specific chemical environments, HDPE may corrode, dissolve, or deform and crack, thus affecting the performance and safety of hemodialysis fluid containers. During dialysis treatment, hemodialysis fluid containers may be subjected to external forces such as pressure, vibration, and impact, causing them to deform or rupture and leak. Therefore, the special material for hemodialysis fluid containers needs to possess sufficient mechanical strength and toughness to ensure the durability and reliability of the dialysis fluid containers, while ensuring the products are sealed, do not leach, and are clean and sterile.

[0004] Currently, most medical device companies use a blend of special hollow blow molding materials, HDPE film, and linear low-density polyethylene to produce hemodialysis fluid containers. This results in products with low cleanliness, poor rigidity-toughness balance, and inconsistent quality. Some products also exhibit problems such as softness, breakage upon drop, and failure to meet thermal oxidative aging standards. Given the problems in hemodialysis fluid container production and the lack of corresponding specialized material production technology, developing a rigidity-toughness balanced medical hollow blow molding material and its preparation method to overcome the challenges of raw material blending and improve the overall performance of the product is of great significance. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low product cleanliness, poor rigidity-toughness balance, and large product quality fluctuations in the existing technology, and to provide a high-density polyethylene composition, a high-density polyethylene material, a preparation method thereof, and its application. The high-density polyethylene material has excellent rigidity-toughness balance, high rigidity and toughness, and excellent resistance to environmental stress cracking, and can be used to prepare medical hollow blow molding materials.

[0006] To achieve the above objectives, the present invention provides a high-density polyethylene composition comprising an ethylene / hexene-1 copolymer resin and a metal soap stabilizer, wherein the weight ratio of the two is 100:0.1-0.3; wherein the ethylene / hexene-1 copolymer resin has a melt flow rate of 12-18 g / 10 min and a density of 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

[0007] The second aspect of this invention provides a method for preparing high-density polyethylene material, the method comprising: mixing ethylene / hexene-1 copolymer resin and a metal soap stabilizer, followed by melting, plasticizing, extrusion and granulation to obtain high-density polyethylene material;

[0008] The weight ratio of the ethylene / hexene-1 copolymer resin to the metal soap stabilizer is 100:0.1-0.3; the melt flow rate of the ethylene / hexene-1 copolymer resin is 12-18 g / 10 min, and the density is 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

[0009] A third aspect of the present invention provides a high-density polyethylene material prepared by the preparation method described in the second aspect above.

[0010] The fourth aspect of the present invention provides the application of the high-density polyethylene composition described in the first aspect or the high-density polyethylene material described in the third aspect in medical hollow blow molding materials or food packaging materials.

[0011] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0012] (1) The high-density polyethylene material of the present invention has excellent rigidity and toughness balance performance, and at the same time has high rigidity and toughness, as well as excellent environmental stress cracking resistance, and can be used to prepare medical hollow blow molding materials.

[0013] (2) The high-density polyethylene material provided by the present invention can be used as a medical hollow blow molding material, which meets the requirements of medical device biological evaluation. It can be used as a special material for hemodialysis fluid buckets, filling the gap in special materials and production technology. It can effectively avoid the problems of low product cleanliness, poor rigidity and toughness balance, and large product quality fluctuation caused by the mixing of different raw materials and the addition of extra additives during the production of hemodialysis fluid buckets, thereby improving product reliability and ensuring the safety of patients' dialysis treatment. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] The first aspect of this invention provides a high-density polyethylene composition comprising an ethylene / hexene-1 copolymer resin and a metal soap stabilizer, wherein the weight ratio of the two is 100:0.1-0.3; wherein the ethylene / hexene-1 copolymer resin has a melt flow rate of 12-18 g / 10 min and a density of 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

[0016] In this invention, ethylene / hexene-1 copolymer resin refers to a resin formed by copolymerizing ethylene and hexene-1.

[0017] Unless otherwise specified, in this invention, the melt flow rate of ethylene / hexene-1 copolymer resin refers to the melt flow rate at a temperature of 190°C and a load of 2.16 kg, that is, the melt flow rate of ethylene / hexene-1 copolymer resin is 12-18 g / 10 min (190°C, 21.6 kg load).

[0018] In this invention, the unit of weight-average molecular weight is g / mol.

[0019] In some embodiments of the present invention, the content of the copolymer units formed by hexene-1 in the ethylene / hexene-1 copolymer resin is 0.1-0.5 mol%.

[0020] In this invention, the content of the copolymer units formed by hexene-1 refers to the molar percentage of hexene-1 entering the copolymer in the copolymer resin formed by copolymerization of ethylene and hexene-1.

[0021] In some embodiments of the present invention, the metal soap stabilizer is selected from one or more of calcium stearate, zinc stearate and magnesium stearate, preferably zinc stearate.

[0022] In some embodiments of the present invention, the high-density polyethylene composition further includes a primary antioxidant and a co-antioxidant, wherein the weight ratio of the ethylene / hexene-1 copolymer resin to the primary antioxidant and the co-antioxidant is 100:0.05-0.25:0.05-0.25.

[0023] In some preferred embodiments of the present invention, the primary antioxidant is selected from one or more of tert-butylphenol antioxidants; for example, in some specific embodiments, the tert-butylphenol antioxidant is pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate (antioxidant 1010) or 2,2'-methylenebis(6-tert-butyl-4-cresol) (antioxidant 2246) from Solvay Group, preferably pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate (antioxidant 1010).

[0024] In some preferred embodiments of the present invention, the auxiliary antioxidant is selected from one or more of phosphite antioxidants; for example, in some specific embodiments, the phosphite antioxidant is tris(2,4-di-tert-butyl)phosphite (antioxidant 168) or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (antioxidant 626) from Solvay Group, preferably tris(2,4-di-tert-butyl)phosphite (antioxidant 168).

[0025] In some preferred embodiments of the present invention, the ethylene / hexene-1 copolymer resin is prepared by a gas-phase method.

[0026] The second aspect of this invention provides a method for preparing high-density polyethylene material, the method comprising: mixing ethylene / hexene-1 copolymer resin and a metal soap stabilizer, followed by melting, plasticizing, extrusion and granulation to obtain high-density polyethylene material;

[0027] The weight ratio of the ethylene / hexene-1 copolymer resin to the metal soap stabilizer is 100:0.1-0.3; the melt flow rate of the ethylene / hexene-1 copolymer resin is 12-18 g / 10 min, and the density is 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

[0028] The high-density polyethylene material of the present invention can be prepared from the high-density polyethylene composition of the first aspect described above. The high-density polyethylene material of the present invention has excellent rigidity-toughness balance properties, and simultaneously possesses high rigidity and toughness, as well as excellent resistance to environmental stress cracking, and can be used to prepare medical hollow blow-molded materials.

[0029] In some embodiments of the present invention, the ethylene / hexene-1 copolymer resin is prepared by a gas-phase method.

[0030] In this invention, the gas phase method specifically refers to the gas phase polyethylene production process (GPE technology).

[0031] In some preferred embodiments of the present invention, the method for preparing the ethylene / hexene-1 copolymer resin includes: in a gas-phase polyethylene production process in which the condenser is in a circulating state, reacting ethylene, hexene-1 and hydrogen in the presence of a polymerization catalyst to obtain the ethylene / hexene-1 copolymer resin.

[0032] In this invention, hydrogen is added as a molecular weight regulator in the reaction of ethylene and hexene-1 to adjust the molecular weight of the copolymer.

[0033] In some preferred embodiments of the present invention, the reaction is carried out in a fluidized bed reactor at a temperature of 104-110°C, a pressure of 2-2.2 MPa, and an ethylene partial pressure of 0.75-0.95 MPa.

[0034] In some embodiments of the present invention, the mass ratio of hexene-1 to ethylene is 0.002-0.01:1; for example, 0.002:1, 0.003:1, 0.004:1, 0.005:1, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, and any value within the range of any two values, preferably 0.004-0.008:1.

[0035] In this invention, the mass ratio of hexene-1 to ethylene of 0.002-0.01:1 refers to the raw material concentration ratio in the reactor.

[0036] In some embodiments of the present invention, the mass ratio of hydrogen to ethylene is 0.00001-0.00004:1; for example, 0.00001:1, 0.00002:1, 0.00003:1, 0.00004:1, and any value within the range of any two values, preferably 0.00001:1-0.00002:1.

[0037] In some embodiments of the present invention, the condenser is isopentane, preferably, the partial pressure ratio of isopentane to ethylene is 0.3-0.5:1; for example, 0.3:1, 0.4:1, 0.5:1, and any value in the range of any two values, such as 0.3-0.4:1.

[0038] The preferred specifications for the ethylene described in this invention are: ethylene purity ≥ 99.95%, C2H2 ≤ 5 × 10⁻⁶. -6 CO≤2×10 -6 CO2≤5×10 -6 O2≤2×10 -6 H2O≤5×10 -6 COS≤0.02×10 -6 .

[0039] The preferred specifications for hexene-1 in this invention are: hexene-1 purity ≥ 99.2%, H2O ≤ 20 × 10⁻⁶. -6 Carbonyl compounds ≤2×10 -6 Internal olefins ≤ 0.8 × 10 -6 Peroxides ≤ 1 × 10 -6 Total sulfur ≤ 1×10 -6 .

[0040] The preferred specifications for isopentane in this invention are: isopentane purity ≥ 95.0%, unsaturated hydrocarbons ≤ 500 × 10⁻⁶. -6 Total sulfur ≤ 5 × 10 -6 H2O≤20×10 -6 CO≤5×10 -6 CO2≤5×10 -6 .

[0041] The preferred specifications for the hydrogen gas described in this invention are: hydrogen purity ≥ 95.0%, H2O ≤ 2 × 10⁻⁶. -6 CO≤0.03×10 -6 CO2 ≤ 0.4 × 10 -6 O2≤5×10 -6 Total sulfur ≤ 1×10 -6 .

[0042] In some embodiments of the present invention, the polymerization catalyst is an inorganic chromium-based catalyst. Preferably, the mass ratio of the polymerization catalyst to ethylene is 0.00006-0.00012:1, for example, 0.00006:1, 0.00007:1, 0.00008:1, 0.00009:1, 0.0001:1, 0.00011:1, 0.00012:1, and any value within the range of any two values, preferably 0.00008-0.0001:1.

[0043] In some embodiments of the present invention, the content of the copolymer units formed by hexene-1 in the ethylene / hexene-1 copolymer resin is 0.1-0.5 mol%.

[0044] In some embodiments of the present invention, the metal soap stabilizer is selected from one or more of calcium stearate, zinc stearate and magnesium stearate, preferably zinc stearate.

[0045] In some embodiments of the present invention, during the mixing of ethylene / hexene-1 copolymer resin and metal soap stabilizer, a primary antioxidant and a co-antioxidant are also added, wherein the weight ratio of ethylene / hexene-1 copolymer resin to primary antioxidant and co-antioxidant is 100:0.05-0.25:0.05-0.25.

[0046] In some preferred embodiments of the present invention, the primary antioxidant is selected from one or more of tert-butylphenol antioxidants, more preferably pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate.

[0047] In some preferred embodiments of the present invention, the antioxidant is selected from one or more of phosphite antioxidants, more preferably tris(2,4-di-tert-butyl)phosphite.

[0048] In some embodiments of the present invention, the melting, plasticizing, extrusion, and granulation are carried out in a twin-screw extruder. During the compounding and granulation process in the twin-screw extruder, the temperature of the first section of the barrel is adjusted to 140°C, the temperature of the second section to 200°C, and the temperature of the third section to 240°C. The temperature of the heat transfer oil heating the twin-screw extruder is set to 250°C, and the temperature of the cooling water is adjusted to 50-70°C, with a cooling water flow rate of 500-700 m³ / h. 3 / h.

[0049] According to a particularly preferred embodiment of the present invention, the preparation method includes the following steps:

[0050] (1) In the gas-phase polyethylene production process where the condenser is in a circulating state, ethylene, hexene-1, and hydrogen enter the fluidized bed reactor and react under the action of the polymerization catalyst to produce a melt flow rate of 12-18 g / 10 min (190℃, 21.6 kg load) and a resin density of 0.95-0.955 g / cm³. 3 The content of the copolymer units formed by hexene-1 is 0.1-0.5 mol%, the weight average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

[0051] (2) Take ethylene / hexene-1 copolymer resin, main antioxidant, co-antioxidant and metal soap stabilizer, mix them evenly and add them to a twin-screw extruder for melting, plasticizing, extrusion and granulation to obtain granular high-density polyethylene hollow blow molding material.

[0052] A third aspect of the present invention provides a high-density polyethylene material prepared by the preparation method described in the second aspect above.

[0053] In this invention, by controlling the parameters of the ethylene / hexene-1 copolymer resin and adjusting its internal molecular structure, a high-density polyethylene material with excellent rigidity-toughness balance is obtained, which can be used to prepare medical hollow blow molding materials.

[0054] The high-density polyethylene material provided by this invention can be used as a medical hollow blow molding material, meeting the requirements for biological evaluation of medical devices. It can be used as a special material for processing hemodialysis fluid buckets, filling the gap in special materials and production technology. It can effectively avoid problems such as low product cleanliness, poor rigidity-toughness balance, and large product quality fluctuations caused by the mixing of different raw materials and the addition of extra additives during the production of hemodialysis fluid buckets, thereby improving product reliability and ensuring the safety of patients' dialysis treatment.

[0055] The fourth aspect of the present invention provides the application of the high-density polyethylene composition described in the first aspect or the high-density polyethylene material described in the third aspect in medical hollow blow molding materials or food packaging materials.

[0056] In some embodiments of the present invention, the medical hollow blow molding material includes a special material for preparing hemodialysis fluid tanks.

[0057] The medical hollow blow molding material provided by this invention has a moderate hexene-1 content, a wide molecular weight distribution, high melt strength, high rigidity, good toughness, and excellent resistance to environmental stress cracking. The material meets the requirements for biological evaluation of medical devices and can be used as a special material for processing hemodialysis fluid tanks, filling the gap in special materials and production technology.

[0058] Using the medical hollow blow molding material provided by this invention can effectively avoid problems such as low product cleanliness, poor rigidity-toughness balance, and large product quality fluctuations caused by the mixing of different raw materials and the addition of extra additives during the production of hemodialysis fluid containers, thereby improving product reliability and ensuring the safety of patients' dialysis treatment.

[0059] The present invention will be described in detail below through preparation examples and embodiments, but the scope of protection of the present invention is not limited to the following description.

[0060] Unless otherwise specified in the following preparation examples, embodiments, and comparative examples, all conditions should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0061] The polymerization catalyst is SLH-611, an inorganic chromium-based catalyst produced by Shanghai Lide Catalyst Co., Ltd.

[0062] The test methods used in the examples and comparative examples are as follows:

[0063] Melt flow rate: Tested according to GB / T3682.1-2018, with a weight of 21.6 kg and a temperature of 190℃;

[0064] Density: Tested according to GB / T 1033.2-2010;

[0065] Weight-average molecular weight and molecular weight distribution: determined by gel permeation chromatography (GPC);

[0066] Yellow Index: Tested according to HG / T 3862-2006;

[0067] Tensile yield strength and nominal strain at tensile fracture: tested according to GB / T 1040.2-2022;

[0068] Flexural modulus: Tested according to GB / T 9341-2008;

[0069] Notched impact strength of simply supported beams: tested according to GB / T 1043.1-2008;

[0070] Environmental stress cracking time: According to condition B of GB / T 1842-2008;

[0071] Oxidation induction time: Tested according to GB / T 19466.6-2009;

[0072] Hexane extract content: tested according to GB / T 5009.58-2003.

[0073] Examples 1-8

[0074] A gas-phase polyethylene process is employed, with isopentane as the condenser continuously circulating. Ethylene, hexene-1, and hydrogen are injected separately into a fluidized bed reactor, and an inorganic chromium-based catalyst is added to react and obtain ethylene / hexene-1 copolymer powder. The ethylene / hexene-1 copolymer powder, antioxidant, auxiliary antioxidant, and metal soap stabilizer are then mixed uniformly and added to a twin-screw extruder for melting, plasticizing, extrusion, and granulation to obtain granular high-density polyethylene hollow blow molding material. The extruder barrel temperature is 140℃ in the first section, 200℃ in the second section, and 240℃ in the third section. The heat transfer oil heating the extruder is at 250℃, and the cooling water temperature is adjusted to 50-70℃ with a flow rate of 500-700 m³ / h. 3 / h.

[0075] The preparation conditions of the hollow blow-molded materials in Examples 1-8 are detailed in Table 1, and the performance characterization results of the obtained hollow blow-molded materials are detailed in Table 2.

[0076] Example 9

[0077] Hollow blown material was prepared according to the method in Example 3, except that the reaction temperature in the reactor was 105℃. The performance characterization results of the obtained hollow blown material are detailed in Table 3.

[0078] Example 10

[0079] Hollow blown material was prepared according to the method in Example 3, except that the mass ratio of hexene-1 to ethylene in the reactor was 0.01:1. The performance characterization results of the obtained hollow blown material are detailed in Table 3.

[0080] Comparative Example 1

[0081] Hollow blown material was prepared according to the method in Example 3, except that the content of hexene-1 in the reactor was 0, and homopolymer polyethylene resin powder was obtained; the performance characterization results of the obtained hollow blown material are detailed in Table 3.

[0082] Comparative Example 2

[0083] Hollow blown material was prepared according to the method in Example 3, except that zinc stearate was replaced with an equal mass of light stabilizer poly[1,6-hexanediamine,N,N'-bis(2,2,6,6-tetramethyl-4-pyridyl)-morpholine-2,4,6-trichloro-1,3,5-triazine]. The performance characterization results of the obtained hollow blown material are detailed in Table 3.

[0084] Comparative Example 3

[0085] Hollow blow molding materials were prepared according to the method of Example 3, except that the ethylene / hexene-1 copolymer polyethylene powder described in Example 3 was replaced with homopolymer polyethylene powder and linear low-density polyethylene powder in Comparative Example 1. The mass ratio of homopolymer polyethylene powder to linear low-density polyethylene powder was 1:1, the melt flow rate of the linear low-density polyethylene powder was 87.5 g / 10 min, and the density was 0.935 g / cm³. 3 The weight-average molecular weight is 75,000, and the molecular weight distribution is 4.5. The performance characterization results of the hollow blow-molded material are detailed in Table 3.

[0086] Table 1. Preparation conditions of hollow blow-molded materials in Examples 1-8

[0087]

[0088]

[0089] Table 2 Characterization results of hollow blow-molded materials in Examples 1-8

[0090]

[0091]

[0092] In the table, the content of hexene-1 unit specifically refers to the content of structural units formed by hexene-1 in the obtained ethylene / hexene-1 copolymer powder.

[0093] Table 3 Characterization results of hollow blow-molded materials from Examples 9-10 and Comparative Examples 1-3

[0094]

[0095] In the table, the content of hexene-1 unit specifically refers to the content of structural units formed by hexene-1 in the obtained ethylene / hexene-1 copolymer powder.

[0096] The results in Tables 2 and 3 show that the hollow blow-molded materials prepared in Examples 1-10, compared with the hollow blow-molded materials prepared in Comparative Examples 1-3, as well as small hollow special materials, HDPE film materials, and linear low-density polyethylene that need to be blended in the market, exhibit superior and more balanced rigidity and toughness properties. Furthermore, they possess higher oxidation induction time and lower n-hexane extract content, resulting in significant improvements in all indicators. Therefore, the hollow blow-molded material provided by this invention features adjustable molecular structure, high tensile yield strength, good impact resistance, and excellent resistance to environmental stress cracking and thermo-oxidative aging.

[0097] This invention employs a gas-phase polyethylene production process (GPE technology) and provides a method and conditions for preparing medical hollow blow molding materials based on the requirements for special materials used in hemodialysis fluid containers, filling a gap in special materials and production technologies.

[0098] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A high-density polyethylene composition, characterized in that, The high-density polyethylene composition comprises an ethylene / hexene-1 copolymer resin and a metal soap stabilizer, with a weight ratio of 100:0.1-0.3; wherein the ethylene / hexene-1 copolymer resin has a melt flow rate of 12-18 g / 10 min and a density of 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

2. The high-density polyethylene composition according to claim 1, wherein, In the ethylene / hexene-1 copolymer resin, the content of copolymer units formed by hexene-1 is 0.1-0.5 mol%.

3. The high-density polyethylene composition according to claim 1 or 2, wherein, The metal soap stabilizer is selected from one or more of calcium stearate, zinc stearate and magnesium stearate, preferably zinc stearate.

4. The high-density polyethylene composition according to any one of claims 1-3, wherein, The high-density polyethylene composition further includes a primary antioxidant and a co-antioxidant, wherein the weight ratio of the ethylene / hexene-1 copolymer resin to the primary antioxidant and the co-antioxidant is 100:0.05-0.25:0.05-0.25; Preferably, the primary antioxidant is selected from one or more of tert-butylphenol antioxidants, more preferably pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate; Preferably, the antioxidant is selected from one or more of phosphite antioxidants, more preferably tris(2,4-di-tert-butyl)phosphite.

5. The high-density polyethylene composition according to any one of claims 1-4, wherein, The ethylene / hexene-1 copolymer resin was prepared by a gas-phase method.

6. A method for preparing a high-density polyethylene material, characterized in that, The preparation method includes: mixing ethylene / hexene-1 copolymer resin and metal soap stabilizer, followed by melting, plasticizing, extrusion and granulation to obtain high-density polyethylene material; The weight ratio of the ethylene / hexene-1 copolymer resin to the metal soap stabilizer is 100:0.1-0.3; the melt flow rate of the ethylene / hexene-1 copolymer resin is 12-18 g / 10 min, and the density is 0.95-0.955 g / cm³. 3 The weight-average molecular weight is 160,000-220,000, and the molecular weight distribution is 12-17.

7. The preparation method according to claim 6, wherein, The ethylene / hexene-1 copolymer resin was prepared by a gas-phase method. Preferably, the method for preparing the ethylene / hexene-1 copolymer resin includes: in a gas-phase polyethylene production process where the condenser is in a circulating state, reacting ethylene, hexene-1 and hydrogen in the presence of a polymerization catalyst to obtain the ethylene / hexene-1 copolymer resin. More preferably, the reaction is carried out in a fluidized bed reactor at a temperature of 104-110°C, a pressure of 2-2.2 MPa, and an ethylene partial pressure of 0.75-0.95 MPa. More preferably, the mass ratio of hexene-1 to ethylene is 0.002-0.01:1; More preferably, the mass ratio of hydrogen to ethylene is 0.00001-0.00004:1; More preferably, the condenser is isopentane, and preferably, the partial pressure ratio of isopentane to ethylene is 0.3-0.5:1; More preferably, the polymerization catalyst is an inorganic chromium-based catalyst, and preferably, the mass ratio of the polymerization catalyst to ethylene is 0.00006-0.00012:

1.

8. The preparation method according to claim 6 or 7, wherein, In the ethylene / hexene-1 copolymer resin, the content of the copolymer units formed by hexene-1 is 0.1-0.5 mol%. And / or, the metal soap stabilizer is selected from one or more of calcium stearate, zinc stearate and magnesium stearate, preferably zinc stearate; And / or, during the mixing of ethylene / hexene-1 copolymer resin and metal soap stabilizer, a primary antioxidant and a co-antioxidant are also added, wherein the weight ratio of ethylene / hexene-1 copolymer resin to primary antioxidant and co-antioxidant is 100:0.05-0.25:0.05-0.25; Preferably, the primary antioxidant is selected from one or more of tert-butylphenol antioxidants, more preferably pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate; Preferably, the antioxidant is selected from one or more of phosphite antioxidants, more preferably tris(2,4-di-tert-butyl)phosphite.

9. A high-density polyethylene material prepared by the preparation method according to any one of claims 6-8.

10. The use of the high-density polyethylene composition according to any one of claims 1-5 or the high-density polyethylene material according to claim 9 in medical hollow blow molding materials or food packaging materials.

11. The application according to claim 10, wherein, The medical hollow blow molding material is used to manufacture hemodialysis fluid containers.

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