High-density polyethylene modified material resistant to marlorol test as well as preparation method and application of high-density polyethylene modified material

Abstract

The invention belongs to the technical field of high polymer material modification, and particularly relates to a high-density polyethylene modified material resistant to a marlorol test as well as a preparation method and application of the high-density polyethylene modified material. The high-density polyethylene modified material resistant to the marlorol test is prepared from the following raw materials in parts by mass: 70 to 90 parts of high-density polyethylene resin, 4.5 to 25 parts of ethylene-vinyl acetate copolymer and 0.5 to 5 parts of processing aid, and the density of the high-density polyethylene resin is 0.945-0.965 g / cm < 3 >. The high-density polyethylene modified material resistant to the marlorol test has excellent impact resistance and environmental stress cracking resistance, especially high-temperature resistance and low-temperature impact resistance, and the phenomenon that the high-density polyethylene modified material is cracked or fractured under severe environments of sun exposure, rain exposure, temperature difference change and long-term load is avoided.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, specifically relating to a high-density polyethylene modified material resistant to marophenol testing, its preparation method, and its application. Background Technology

[0002] High-density polyethylene (HDPE) is widely used in high-speed rail rebound pads due to its excellent toughness and chemical corrosion resistance. However, HDPE used in high-speed rail rebound pads is prone to cracking or breakage when subjected to high-frequency, high-intensity cyclic impact loads, as well as in harsh environments such as sun exposure, rain, and temperature fluctuations. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a high-density polyethylene modified material resistant to marophenol testing, its preparation method and application. The high-density polyethylene modified material resistant to marophenol testing provided by the present invention has excellent impact resistance, environmental stress cracking resistance, and especially high temperature and low temperature impact resistance, avoiding cracking or breakage under harsh environments such as sun exposure, rain, temperature changes and long-term load.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a high-density polyethylene modified material resistant to marophenol testing, comprising the following raw materials by mass: 70-90 parts of high-density polyethylene resin; 4.5 to 25 parts of ethylene-vinyl acetate copolymer; Processing aids: 0.5-5 parts; The density of the high-density polyethylene resin is 0.945~0.965 g / cm³. 3 .

[0005] Preferably, the high-density polyethylene resin is one or more of CNOOC Shell 5021D, CNOOC Shell 5121B, and Dow KS10100UE.

[0006] Preferably, the ethylene-vinyl acetate copolymer is one or more of Formosa Plastics 7470M, Yanshan Petrochemical 18J3, and Yangzi BASF 5110J.

[0007] Preferably, the processing aid is one or more of antioxidants, nucleating agents, lubricants, and black masterbatches.

[0008] Preferably, the antioxidant is antioxidant 168 and / or antioxidant 1098.

[0009] Preferably, the nucleating agent is talc HTPultra5 L and / or nucleating agent P22.

[0010] Preferably, the lubricant is one or more of lubricant 540A, lubricant PETS-AP, and lubricant EBS-B50.

[0011] This invention also provides a method for preparing the high-density polyethylene modified material resistant to malophenol testing as described in the above technical solution, comprising the following steps: High-density polyethylene resin, ethylene-vinyl acetate copolymer, and processing aids are mixed to obtain the high-density polyethylene modified material resistant to marophenol testing.

[0012] Preferably, the equipment used for mixing is a high-low mixing machine or a twin-screw extruder.

[0013] The present invention also provides the application of the high-density polyethylene modified material resistant to marophenol test described in the above technical solution or the high-density polyethylene modified material resistant to marophenol test prepared by the preparation method described in the above technical solution in the preparation of insulating buffer pads and / or rebound pads in high-speed rail systems.

[0014] This invention provides a high-density polyethylene modified material resistant to marophenol testing, comprising the following raw materials by mass: 70-90 parts of high-density polyethylene resin; 4.5 to 25 parts of ethylene-vinyl acetate copolymer; Processing aids: 0.5-5 parts; The density of the high-density polyethylene resin is 0.945~0.965 g / cm³. 3 .

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By optimizing the molecular structure of high-density polyethylene material through ethylene-vinyl acetate copolymer and processing aids, the impact resistance of the material is significantly improved, and the low-temperature impact performance of the material in the cold environment is improved, effectively solving the problem that traditional materials are prone to cracking or breaking under low-temperature conditions.

[0016] 2. This invention uses processing aids such as antioxidants, nucleating agents, and lubricants to improve material properties while maintaining the material's resistance to environmental stress cracking, effectively preventing cracking or fracture under long-term load.

[0017] 3. By precisely controlling the proportions of each component, an optimized balance of material properties is achieved, ensuring both high strength and chemical corrosion resistance while reducing the release of harmful substances and improving the material's environmental performance.

[0018] 4. The modified material of the present invention has excellent processing performance and product appearance performance, which can meet the application needs of different fields, and is particularly suitable for insulating buffer pads and rebound pads in high-speed rail systems. Attached Figure Description

[0019] Figure 1 Here is a photograph of the high-speed rail rebound pad prepared according to the present invention; Figure 2 This is a graph showing the relationship between the vinyl acetate (VA) content in the product and the marophenol resistance test time. Detailed Implementation

[0020] This invention provides a high-density polyethylene modified material resistant to marophenol testing, comprising the following raw materials by mass: 70-90 parts of high-density polyethylene resin; 4.5 to 25 parts of ethylene-vinyl acetate copolymer; Processing aids: 0.5-5 parts; The density of the high-density polyethylene resin is 0.945~0.965 g / cm³. 3 .

[0021] Unless otherwise specified, the present invention does not have special requirements on the source of raw materials used, and commercially available products well known to those skilled in the art can be used.

[0022] The raw materials for preparing the high-density polyethylene modified material resistant to marophenol testing provided by the present invention include 70 to 90 parts by weight of high-density polyethylene resin, specifically 78, 83, 88, or 90 parts in the embodiments.

[0023] In one embodiment, the density of the high-density polyethylene resin is 0.945~0.965 g / cm³. 3 In a specific embodiment, the value is 0.953 g / cm³. 3 The high-density polyethylene resin is one or more of CNOOC Shell 5021D, CNOOC Shell 5121B and Dow KS10100UE, and in a specific embodiment it is Dow KS10100UE.

[0024] The raw materials for preparing the high-density polyethylene modified material resistant to marophenol testing provided by the present invention include 4.5 to 25 parts by weight of ethylene-vinyl acetate copolymer, specifically 8, 10, 15 or 20 parts in the embodiments.

[0025] In one embodiment, the ethylene-vinyl acetate copolymer is one or more of Formosa Plastics 7470M, Yanshan Petrochemical 18J3, and Yangzi BASF 5110J, with Formosa Plastics 7470M being a specific example.

[0026] The raw materials for preparing the high-density polyethylene modified material resistant to marophenol testing provided by the present invention include 0.5 to 5 parts by weight of processing aids, specifically 2 to 4 parts in the embodiment.

[0027] In one embodiment, the processing aid is one or more of antioxidants, nucleating agents, lubricants, and black masterbatches, specifically antioxidants, nucleating agents, lubricants, and black masterbatches; the antioxidant is antioxidant 168 and / or antioxidant 1098, specifically antioxidant 168 and antioxidant 1098; the chemical name of antioxidant 168 is tris(2,4-di-tert-butylphenyl) phosphite, and the chemical name of antioxidant 1098 is N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide); the nucleating agent is talc HTPultra5 L and / or nucleating agent P22, specifically nucleating agent P22; talc HTPultra5 L... The chemical composition of L includes SiO2 with a mass fraction of ≥60% and MgO with a mass fraction of ≥30%; the nucleating agent P22 is a fine powder mixture of organic and inorganic components; the lubricant is one or more of lubricant 540A, lubricant PETS-AP, and lubricant EBS-B50, with lubricant 540A being used in a specific embodiment; lubricant 540A is a polymer of 2-acrylic acid and ethylene, lubricant PETS-AP is chemically named pentaerythritol stearate, and lubricant EBS-B50 is chemically named N,N'-ethylene bis-stearamide; the black masterbatch is a black masterbatch with a carbon black content of more than 50% and a polyethylene (PE) carrier.

[0028] As one embodiment, the tensile strength of the high-density polyethylene modified material subjected to the marophenol test is ≥16MPa, and the marophenol test time is ≥120h.

[0029] This invention provides a method for preparing the high-density polyethylene modified material resistant to malophenol testing as described in the above technical solution, comprising the following steps: High-density polyethylene resin, ethylene-vinyl acetate copolymer, and processing aids are mixed to obtain the high-density polyethylene modified material resistant to marophenol testing.

[0030] In one embodiment, the mixing equipment is a high-low mixing machine or a twin-screw extruder, specifically a high-low mixing machine. When the mixing equipment is a high-low mixing machine, the mixing time is 20-30 minutes, specifically 20-25 minutes in this embodiment; when the mixing equipment is a twin-screw extruder, the mixing is melt blending; the melt blending temperature is 180-220°C, specifically 200°C in this embodiment; the screw length-to-diameter ratio (L / D) of the twin-screw extruder is 20-40:1, specifically 32:1 in this embodiment, and the screw speed of the twin-screw extruder during processing is 300-500 rpm, specifically 400 rpm in this embodiment.

[0031] The high-density polyethylene modified material prepared by this invention has excellent impact resistance, especially low-temperature impact resistance in harsh environments, effectively solving the problem of traditional materials being prone to cracking or breaking under low-temperature conditions. It also has excellent creep resistance, weather resistance, fatigue resistance, high-temperature resistance and environmental stress cracking resistance, and is particularly suitable for insulating buffer pads and rebound pads in high-speed rail systems.

[0032] The present invention also provides the application of the high-density polyethylene modified material resistant to marophenol test described in the above technical solution or the high-density polyethylene modified material resistant to marophenol test prepared by the preparation method described in the above technical solution in the preparation of insulating buffer pads and / or rebound pads in high-speed rail systems.

[0033] In one embodiment, the insulating buffer pads and / or rebound pads in the high-speed rail system are injection molded from high-density polyethylene modified material that is resistant to marophenol testing.

[0034] In one embodiment, the injection temperature includes 180~210℃ for the feed section, 200~230℃ for the intermediate section, and 200~220℃ for the nozzle section; in a specific embodiment, the feed section is 200℃, the intermediate section is 220℃, and the nozzle section is 210℃.

[0035] In one embodiment, the injection pressure is 90~130MPa, specifically 95MPa, and the holding pressure is 50~90MPa, specifically 80MPa.

[0036] In one embodiment, the temperature of the mold used for injection molding is 40~60℃, specifically 50℃, and the back pressure is 10~15MPa, specifically 13MPa.

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0038] Example 1 A method for preparing high-density polyethylene modified materials resistant to marophenol testing includes the following steps: High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 3 90 parts of ethylene-vinyl acetate copolymer (Formosa Plastics 7470M), 8 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were thoroughly mixed in a high and low mixer for 20 minutes to obtain a uniformly dispersed modified resin.

[0039] Example 2 A method for preparing high-density polyethylene modified materials resistant to marophenol testing includes the following steps: High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 3 88 parts of ethylene-vinyl acetate copolymer (Formosa Plastics 7470M), 10 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were thoroughly mixed in a high and low mixing machine for 20 minutes to obtain a uniformly dispersed modified resin.

[0040] Example 3 A method for preparing high-density polyethylene modified materials resistant to marophenol testing includes the following steps: High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 3 83 parts of ethylene-vinyl acetate copolymer (Formosa Plastics 7470M), 15 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were thoroughly mixed in a high and low mixing machine for 20 minutes to obtain a uniformly dispersed modified resin.

[0041] Example 4 A method for preparing high-density polyethylene modified materials resistant to marophenol testing includes the following steps: High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 378 parts of ethylene-vinyl acetate copolymer (Formosa Plastics 7470M), 20 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were thoroughly mixed in a high-low mixer for 20 minutes to obtain a uniformly dispersed modified resin.

[0042] Example 5 A method for preparing high-density polyethylene modified materials resistant to marophenol testing includes the following steps: High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 3 78 parts of ethylene-vinyl acetate copolymer (Formosa Plastics 7470M), 20 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were melt-blended in a twin-screw extruder at 200°C. The length-to-diameter ratio (L / D) of the twin-screw extruder was 32:1, and the screw speed of the twin-screw extruder during processing was 400 rpm to obtain the modified resin.

[0043] Comparative Example 1 High-density polyethylene resin (Dow KS10100UE, density 0.953 g / cm³) was used. 3 98 parts and 2 parts of processing aids (antioxidant 168 and antioxidant 1098, nucleating agent (nucleating agent P22), lubricant (lubricant 540A) and black masterbatch in a mass ratio of 0.5:0.5:0.5:1) were thoroughly mixed in a high-low mixer for 20 minutes to obtain a uniformly dispersed modified resin.

[0044] Application Example 1 Using an injection molding machine, the modified resin prepared in Example 1 was injection molded. The injection temperatures were 200°C at the feed section, 220°C at the intermediate section, and 210°C at the nozzle section. The injection pressure was 95 MPa, the holding pressure was 80 MPa, the mold temperature was 50°C, and the back pressure was 13 MPa, resulting in a high-speed rail springback pad (the actual object is shown in the image). Figure 1 (as shown) and standard tensile specimens (used to test the mechanical strength of products).

[0045] Application Examples 2-5 and Comparative Application Example 1 The difference from Application Example 1 is that the modified resin prepared in Example 1 was replaced with the modified resin prepared in Examples 2-5 and Comparative Example 1, respectively.

[0046] Performance testing The samples (high-speed rail rebound pad and standard tensile specimen) prepared for corresponding use cases 1 to 5 and comparative application example 1 were subjected to tensile strength and marophenol tests, and the results are shown in Table 1.

[0047] The tensile strength test method refers to ISO 527-2, and the tensile strength test should be carried out strictly in accordance with this standard; The marophenol reagent (CAS No. 127087-87-0, or 37205-87-1) specified as NP9.5 is used in the marophenol test, and the NP9.5 content in the marophenol test solvent preparation is 5%. The test condition is 60℃. The specific test steps are as follows: Step 1: Equipment and Reagent Preparation Two sealable stainless steel or glass containers with sufficient volume to hold the test sample are required, along with a high-temperature drying oven, rubber gloves, at least one or two beakers (200mL and 1000mL), and an electronic scale (with a weighing capacity of approximately 2000g). Depending on the shape and quantity of the sample, prepare some metal blocks to hold the test sample in place.

[0048] Marophenol reagent (CAS No. 127087-87-0, or 37205-87-1) in specified specifications (e.g., NP10, NP9.5), distilled water.

[0049] Step 2: Preparation of marophenol aqueous solution Based on the size of the sample and container, estimate the volume required to completely submerge the sample, and estimate the required weight of the aqueous solution, generally in grams and rounded to the nearest hundred.

[0050] Calculate the required amount of marophenol reagent, weigh it in a small beaker and pour it into the prepared solution container. Because the reagent has a high viscosity, it is difficult to dissolve in water at room temperature or low temperature, so it is difficult to pour it out completely and cannot be rinsed clean with the water to be added. Therefore, the beaker can be placed directly into the solution preparation container.

[0051] Calculate the required amount of water (distilled water) according to the required concentration, weigh it in a large beaker and pour it into the solution preparation container.

[0052] Stir appropriately, then cover with a sealed lid and place the container in a high-temperature drying oven (note that if the oven uses bottom heating wires, the container cannot be placed directly on the bottom plate of the oven; at least one supporting plate is required to prevent the actual temperature of the bottom plate from being significantly higher than the required set temperature due to direct heat radiation from the heating wires). Heat at the specified temperature (generally 40~60℃) to ensure that marophenol dissolves well in water and that the solution reaches the temperature required for testing.

[0053] Step 3: Sample Placement Place the test sample into the test container. Sample placement rules: A. If prestressing or pre-deformation is required, fix the specified sample strip to the fixture with the required curvature. The sample strip should be exposed as much as possible to ensure full contact with the solvent. If there are multiple fixtures, they must not be directly stacked to avoid subjecting the sample to additional stress. B. If prestressing or pre-deformation is not required, place the sample directly into the test container. If there are multiple samples, they must not be directly stacked; a sample holder or support can be used for isolation. The sample should have as much surface area as possible in contact with the solvent. Parts of the sample with high stress, such as the main testing areas, bending or arc transition surfaces, and areas with abrupt changes in thickness, must not be directly overlapped or touched to ensure full contact with the solvent and avoid additional forces.

[0054] After the sample is placed, since HDPE has a lower specific gravity than the solution, to prevent the sample from floating after being added, a metal weight needs to be placed on top of the sample. The weight should not be placed on the main testing area or the area with high stress.

[0055] Table 1. Test results of samples prepared in Application Examples 1-5 and Comparative Application Example 1.

[0056] Note: The NP9.5 content in the marophenol experimental solvent preparation was 5%, and the test conditions were 60℃.

[0057] Figure 2 The graph shows the relationship between the vinyl acetate (VA) content of the product and the time required for the marophenol resistance test. The VA content is 0% for the control application example 1, 1.3% for the application example 1, 2.6% for the application example 2, 3.9% for the application example 3, and 5.2% for the application example 4.

[0058] From Table 1 and Figure 2 As can be seen from Application Examples 4 and 5, when the proportions of high-density polyethylene resin, ethylene-vinyl acetate copolymer, and processing aids are the same, the modified resin prepared by a twin-screw extruder exhibits significantly reduced tensile strength and marophenol test time. This is because during the twin-screw extrusion process, some resin decomposes under high temperature and shear force. Therefore, when processing such products, a high-low mixing mill should be selected for preparation.

[0059] By comparing Application Example 1, Application Example 2, Application Example 3, and Application Example 4, it was found that in the material system, as the VA content increases, the tensile strength of the product gradually decreases, and the marophenol resistance test time gradually increases. Moreover, when the VA content is between 1.3% and 5.2%, the marophenol resistance test time is ≥144h.

[0060] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A high-density polyethylene modified material resistant to malophenol testing, characterized in that, The following raw materials are included in the preparation by mass parts: 70-90 parts of high-density polyethylene resin; 4.5 to 25 parts of ethylene-vinyl acetate copolymer; Processing aids: 0.5-5 parts; The density of the high-density polyethylene resin is 0.945~0.965 g / cm³. 3 .

2. The high-density polyethylene modified material according to claim 1, characterized in that, The high-density polyethylene resin is one or more of CNOOC Shell 5021D, CNOOC Shell 5121B, and Dow KS10100UE.

3. The high-density polyethylene modified material resistant to malophenol testing according to claim 1, characterized in that, The ethylene-vinyl acetate copolymer is one or more of Formosa Plastics 7470M, Yanshan Petrochemical 18J3, and Yangzi BASF 5110J.

4. The high-density polyethylene modified material resistant to malophenol testing according to claim 1, characterized in that, The processing aid is one or more of antioxidants, nucleating agents, lubricants, and black masterbatches.

5. The high-density polyethylene modified material resistant to malophenol testing according to claim 4, characterized in that, The antioxidant is antioxidant 168 and / or antioxidant 1098.

6. The high-density polyethylene modified material resistant to malophenol testing according to claim 4, characterized in that, The nucleating agent is talc HTPultra5 L and / or nucleating agent P22.

7. The high-density polyethylene modified material resistant to malophenol testing according to claim 4, characterized in that, The lubricant is one or more of lubricant 540A, lubricant PETS-AP, and lubricant EBS-B50.

8. A method for preparing the high-density polyethylene modified material resistant to malophenol testing as described in any one of claims 1 to 7, characterized in that, Includes the following steps: High-density polyethylene resin, ethylene-vinyl acetate copolymer, and processing aids are mixed to obtain the high-density polyethylene modified material resistant to marophenol testing.

9. The preparation method according to claim 8, characterized in that, The equipment used for mixing is a high-low mixing machine or a twin-screw extruder.

10. The application of the high-density polyethylene modified material resistant to marophenol test as described in any one of claims 1 to 7, or the high-density polyethylene modified material resistant to marophenol test prepared by the preparation method described in claim 8 or 9, in the preparation of insulating buffer pads and / or rebound pads in high-speed rail systems.

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