Antistatic packing straps and their preparation method

Abstract

This invention relates to the field of polymer compound composition technology, and more particularly to an antistatic packing strap and its preparation method. The packing strap comprises the following components in parts by weight: 60-80 parts polypropylene, 5-10 parts toughening agent, 0.5-2 parts lubricant, 1-5 parts antioxidant, and 2-5 parts polymeric antistatic agent. The invention also provides its preparation method. Compared with the prior art, the packing strap prepared by this invention has a long-lasting antistatic effect, excellent antistatic properties, good mechanical properties, and is less prone to damage during use.

Description

Technical Field

[0001] This invention relates to the field of polymer compound composition technology, and more particularly to an antistatic packing strap and its preparation method. Background Technology

[0002] Polypropylene strapping (PP strapping) is a plastic binding material made from polypropylene fiber-grade resin. It possesses many excellent properties, including good plasticity, high tensile strength, resistance to flexural fatigue, low density, and excellent tensile impact resistance, making it widely used in various fields. PP strapping is lightweight, easy to handle and operate, and its good flexibility allows it to easily wrap items of different shapes. Furthermore, PP strapping has high tensile strength, ensuring secure packaging, and it is also corrosion-resistant, making it suitable for use in various environmental conditions. It is also very easy to operate and compatible with various strapping machines, including fully automatic, semi-automatic, and manual strapping machines. PP strapping is also an environmentally friendly material, recyclable. PP strapping can be classified in many ways, based on production process, raw material source, application scenario, whether it is printed, color, and other criteria. The production process of PP strapping includes steps such as melting plastic granules, pressing, molding, cooling, winding, packaging, and warehousing. During production, controlling temperature and stretch ratio are key factors in ensuring the quality of the strapping. PP strapping is an ideal choice for the packaging industry due to its lightweight, economy, ease of use, and good binding performance. However, polypropylene is a highly insulating material with a very high surface resistivity, making it prone to generating and accumulating static electricity during production and use. Static electricity accumulation can cause various hazards, such as dust attraction, discharge, breakdown, and even potential safety accidents like combustion or explosion. The problem is particularly severe in dry environments, potentially damaging products or disrupting production processes.

[0003] To reduce the risks and losses caused by static electricity, polypropylene strapping requires antistatic treatment. Antistatic treatment typically involves adding specific antistatic agents or conductive fillers to the PP material. These additives improve the material's conductivity, thereby reducing static electricity buildup. The antistatic agent's action includes uniform distribution during extrusion, migration to the surface, formation of a conductive layer, and adsorption of moisture from the air to eliminate static electricity. The antistatic properties of PP material significantly improve with increasing ambient humidity.

[0004] CN108359207A provides a high-strength antistatic polypropylene plastic strapping and its preparation method. The plastic strapping comprises the following components by weight: 80 parts polypropylene, 5-15 parts toughening agent, 5-15 parts filler, 0.1-0.3 parts coupling agent, and 1.7-4.1 parts composite antistatic agent. The preparation method includes the following steps: (1) stirring and drying the polypropylene to obtain dried polypropylene; (2) mixing the toughening agent, filler, coupling agent, and composite antistatic agent to obtain a mixture; (3) processing the dried polypropylene and the mixture in a single-screw extruder to obtain the above-mentioned plastic strapping. The addition of a composite antistatic agent to the raw materials of this invention gives the prepared plastic strapping excellent antistatic properties, high tensile strength, and impact resistance, and it can be used for extrusion stretching processes.

[0005] CN106633362A provides an antistatic, compression-resistant, and breakable packing strap, belonging to the field of packaging material technology. It is prepared from the following components in parts by weight: 100 parts polypropylene fiber resin, 12-18 parts polyethylene octene copolymer elastomer, 10-20 parts modified asphalt, 5-15 parts antistatic agent, 5-8 parts aromatic oil, 0.5-1.5 parts dispersant, 4-6 parts polyacetylene, 8-12 parts carbon fiber, 1-5 parts silane coupling agent, 0.8-1.4 parts C5 resin, and 1-5 parts antioxidant. The packing strap obtained by this invention has a simple structure, is energy-saving and environmentally friendly, has low cost, high strength, high breakage resistance, and good antistatic effect. It contains no harmful substances during production, does not stick together, and has high softness, strength, and toughness, thus possessing broad market potential.

[0006] While small antistatic agents and metal salt additives can exert their antistatic effect by migrating to the surface of polypropylene and absorbing moisture, these agents are susceptible to environmental conditions, causing them to gradually detach and thus weaken or lose their antistatic function. On the other hand, although black conductive inorganic materials can provide long-lasting antistatic properties, they require a large proportion of addition, which may adversely affect the material's mechanical properties and color selection. Therefore, there is an urgent need in the market to develop a polypropylene material that is both easy to produce and can provide long-term stable antistatic properties to meet the production and application needs of polypropylene strapping. Summary of the Invention

[0007] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide an antistatic packing strap and a method for preparing the same.

[0008] Polymer-based antistatic agents achieve their antistatic effect by forming conductive pathways within the polymer matrix. Compared to small-molecule antistatic agents, they are unaffected by environmental humidity and do not affect product color. Furthermore, polymer-based antistatic agents overcome the shortcomings of traditional antistatic agents. Instead of migrating to the surface to absorb moisture, they form a conductive network structure within the matrix, using this network as a pathway to dissipate charge and reduce resistance. Compared to traditional antistatic agents, their antistatic effect is more durable, unaffected by air humidity, and less susceptible to wiping and washing. This invention provides a hydrophilic polymer as an antistatic agent. Allylbenzene, N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and hydroxymethyl methacrylate are free-radical polymerized to obtain a hydrophilic polymer-based antistatic agent. After mixing with polypropylene resin, a network structure is formed within the matrix, allowing accumulated charge to be released through conductive pathways, effectively reducing the volume resistivity of the blend. This polymeric antistatic agent does not rely entirely on surface water absorption, so it is less affected by humidity. Furthermore, due to the polymer's relatively large molecular weight, it cannot easily migrate to the substrate surface and is unaffected by washing or wiping, resulting in a longer-lasting effect. N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, due to its good hydrophilicity, can better adsorb moisture from the air, thus exhibiting a direct antistatic effect. Allylbenzene has better compatibility with polypropylene, while hydroxymethyl methacrylate promotes the absorption of moisture and the dissociation of cations in the quaternary ammonium salt. Therefore, the resulting antistatic agent not only effectively reduces surface resistance but also has minimal impact on the properties of the matrix resin itself. The packing tape prepared by this invention has a long-lasting antistatic effect, excellent antistatic properties, good mechanical properties, and is not easily damaged during use.

[0009] To achieve the above objectives, the present invention provides an antistatic packing strap comprising the following components in parts by weight: 60-80 parts polypropylene, 5-10 parts toughening agent, 0.5-2 parts lubricant, 1-5 parts antioxidant, and 2-5 parts polymer-type antistatic agent.

[0010] Furthermore, the toughening agent is a polyethylene octene copolymer elastomer.

[0011] Furthermore, the lubricant is magnesium stearate.

[0012] Furthermore, the antioxidant is antioxidant 1010.

[0013] The preparation method of the polymer-type antistatic agent includes the following steps:

[0014] Allylbenzene, N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride and hydroxymethyl methacrylate were added to anhydrous ethanol, stirred and mixed evenly, and then an initiator was added. The mixture was heated and reacted for 4-8 hours. The mixture was then concentrated under reduced pressure to evaporate to 1 / 4 of its original volume. Toluene was then added until a precipitate appeared. The mixture was filtered, and the residue was dried to obtain a polymeric antistatic agent.

[0015] Furthermore, the molar ratio of allylbenzene, N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride to hydroxymethyl methacrylate is 10:5 to 10:1 to 5.

[0016] Furthermore, the initiator is azobisisobutyronitrile.

[0017] Furthermore, the amount of the initiator is 0.5 to 1 wt%.

[0018] Furthermore, the temperature range for the heating is 70–80°C.

[0019] A method for preparing an antistatic packing strap includes the following steps:

[0020] S1. Mix polypropylene, toughening agent, lubricant, antioxidant, and polymeric antistatic agent and stir until homogeneous to obtain a mixture;

[0021] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0022] The beneficial effects of this invention are:

[0023] 1. Compared with existing technologies, this invention provides a hydrophilic polymer as an antistatic agent. Allylbenzene, N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and hydroxymethyl methacrylate are free-radical polymerized to obtain a hydrophilic polymeric antistatic agent. After being mixed with polypropylene resin, it forms a network structure in the matrix. The accumulated charge can be released through conductive pathways, effectively reducing the volume resistivity of the blend. This polymeric antistatic agent does not rely entirely on surface water absorption, so it is less affected by humidity. Furthermore, due to the polymer's relatively large molecular weight, it cannot easily migrate to the matrix surface and is not affected by washing or wiping, thus maintaining its effect for a longer period.

[0024] 2. The packing tape prepared by the present invention has a long-lasting antistatic effect, excellent antistatic properties, good mechanical properties, and is not easily damaged during use. Attached Figure Description

[0025] Figure 1 A photo of a sample of the packing tape produced. Detailed Implementation

[0026] This invention provides an antistatic packing strap, comprising the following components: polypropylene, toughening agent, lubricant, antioxidant, and polymeric antistatic agent. The packing strap is obtained by mixing the polypropylene, toughening agent, lubricant, antioxidant, and polymeric antistatic agent to obtain a mixture, followed by compounding and plasticizing, extrusion, cooling and shaping, winding, and packaging.

[0027] Polypropylene, as the matrix material, possesses excellent mechanical properties and chemical stability, and is the main component of strapping. It provides the basic physical properties of strapping, such as strength and durability.

[0028] Toughening agents are used to improve the impact resistance and toughness of polypropylene. They prevent brittle fracture of the material by absorbing and dispersing energy when it is subjected to impact.

[0029] The function of lubricant is to reduce friction between polypropylene and processing equipment during processing, thereby improving processing efficiency. At the same time, it reduces friction during the use of packing straps, making packing and unpacking easier.

[0030] Antioxidants are used to extend the service life of polypropylene by preventing its degradation due to oxidation during processing and use. They protect polypropylene from aging caused by heat and light by capturing free radicals, inhibiting oxidative chain reactions.

[0031] Polymer-type antistatic agents, as key components of antistatic strapping, are prepared by free radical polymerization of allylbenzene, N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and hydroxymethyl methacrylate. After being mixed with polypropylene resin, they form a network structure in the matrix. The accumulated charge can be released through conductive pathways, effectively reducing the volume resistivity of the blend and ensuring that the strapping has stable antistatic properties.

[0032] N,N,N-trimethyl-2-[(2-methylacryloyl)oxy]propan-2-aminium chloride, CAS No.: 93842-91-2.

[0033] Hydroxymethyl methacrylate, CAS No.: 21982-30-9.

[0034] Polypropylene, model: Formosa Plastics 1020 (Taiwan), Dongguan Gansheng Plastics Technology Co., Ltd.

[0035] Polyethylene octene copolymer elastomer, grade: DE2300, Foshan Ruisheng Plastics.

[0036] Example 1

[0037] A method for preparing an antistatic packing strap includes the following steps, in parts by weight:

[0038] S1. Mix 80 parts of polypropylene, 10 parts of polyethylene octene copolymer elastomer, 2 parts of magnesium stearate, 1 part of antioxidant 1010, and 4 parts of polymeric antistatic agent and stir evenly to obtain a mixture.

[0039] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0040] The preparation method of the polymer-type antistatic agent includes the following steps:

[0041] 11.8 parts of allylbenzene, 19.89 parts of N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and 1.16 parts of hydroxymethyl methacrylate were added to 150 parts of anhydrous ethanol. After stirring and mixing evenly, 0.2 parts of azobisisobutyronitrile were added, the temperature was raised to 75°C, and the reaction was carried out for 6 hours. The mixture was then concentrated under reduced pressure to evaporate the volume to 1 / 4 of the original volume. Four times the volume of toluene was then added until a precipitate appeared. The mixture was filtered, and the residue was dried to obtain the polymeric antistatic agent.

[0042] Example 2

[0043] A method for preparing an antistatic packing strap includes the following steps, in parts by weight:

[0044] S1. Mix 80 parts of polypropylene, 10 parts of polyethylene octene copolymer elastomer, 2 parts of magnesium stearate, 1 part of antioxidant 1010, and 2 parts of polymeric antistatic agent and stir evenly to obtain a mixture.

[0045] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0046] The preparation method of the polymer-type antistatic agent includes the following steps:

[0047] 11.8 parts of allylbenzene, 19.89 parts of N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and 1.16 parts of hydroxymethyl methacrylate were added to 150 parts of anhydrous ethanol. After stirring and mixing evenly, 0.2 parts of azobisisobutyronitrile were added, the temperature was raised to 75°C, and the reaction was carried out for 6 hours. The mixture was then concentrated under reduced pressure to evaporate the volume to 1 / 4 of the original volume. Four times the volume of toluene was then added until a precipitate appeared. The mixture was filtered, and the residue was dried to obtain the polymeric antistatic agent.

[0048] Example 3

[0049] A method for preparing an antistatic packing strap includes the following steps, in parts by weight:

[0050] S1. Mix 80 parts of polypropylene, 10 parts of polyethylene octene copolymer elastomer, 2 parts of magnesium stearate, 1 part of antioxidant 1010, and 3 parts of polymeric antistatic agent and stir evenly to obtain a mixture.

[0051] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0052] The preparation method of the polymer-type antistatic agent includes the following steps:

[0053] 11.8 parts of allylbenzene, 19.89 parts of N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and 1.16 parts of hydroxymethyl methacrylate were added to 150 parts of anhydrous ethanol. After stirring and mixing evenly, 0.2 parts of azobisisobutyronitrile were added, the temperature was raised to 75°C, and the reaction was carried out for 6 hours. The mixture was then concentrated under reduced pressure to evaporate the volume to 1 / 4 of the original volume. Four times the volume of toluene was then added until a precipitate appeared. The mixture was filtered, and the residue was dried to obtain the polymeric antistatic agent.

[0054] Example 4

[0055] A method for preparing an antistatic packing strap includes the following steps, in parts by weight:

[0056] S1. Mix 80 parts of polypropylene, 10 parts of polyethylene octene copolymer elastomer, 2 parts of magnesium stearate, 1 part of antioxidant 1010, and 5 parts of polymeric antistatic agent and stir evenly to obtain a mixture.

[0057] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0058] The preparation method of the polymer-type antistatic agent includes the following steps:

[0059] 11.8 parts of allylbenzene, 19.89 parts of N,N,N-trimethyl-2-[(2-methacryloyl)oxy]prop-2-ammonium chloride, and 1.16 parts of hydroxymethyl methacrylate were added to 150 parts of anhydrous ethanol. After stirring and mixing evenly, 0.2 parts of azobisisobutyronitrile were added, the temperature was raised to 75°C, and the reaction was carried out for 6 hours. The mixture was then concentrated under reduced pressure to evaporate the volume to 1 / 4 of the original volume. Four times the volume of toluene was then added until a precipitate appeared. The mixture was filtered, and the residue was dried to obtain the polymeric antistatic agent.

[0060] Compare with Example 1

[0061] A method for preparing an antistatic packing strap includes the following steps, in parts by weight:

[0062] S1. Mix 80 parts of polypropylene, 10 parts of polyethylene octene copolymer elastomer, 2 parts of magnesium stearate, 1 part of antioxidant 1010, and 4 parts of ethoxylated octadecylamine and stir until uniform to obtain a mixture.

[0063] S2. After the mixture is kneaded and plasticized, it is extruded, cooled and shaped, wound up and packaged to obtain antistatic packing straps.

[0064] Test Example 1

[0065] The resistivity of the packing tape sample surface after cooling and molding for 2 hours in the control example and the embodiment was tested using a resistivity meter. The sample surface resistivity was then tested again after being placed at a relative humidity of 80% for 1, 2 and 4 weeks. After 4 weeks, the sample was washed with water and the surface resistivity of the packing tape sample was tested again. The specific results are shown in Table 1.

[0066] Table 1 Surface resistivity of antistatic strapping at different times

[0067]

[0068]

[0069] As shown in Table 1, the surface resistivity of the packing tape in the examples took four weeks to stabilize compared to the control example, while the packing tape in the control example remained essentially unchanged after two weeks. This is because traditional antistatic agents have relatively low molecular weights and are not fully compatible with the plastic matrix when added to polypropylene. During use, the antistatic agent continuously migrates from the interior, absorbing moisture from the air through its end hydrophilic groups, dissipating static charge, and reducing the surface resistivity of the plastic matrix. This precipitation rate is relatively fast, hence the surface resistance of the control example stabilized more quickly. In contrast, the polymeric antistatic agent in the examples has a larger molecular weight and better compatibility with the matrix, making it less prone to precipitation. Moreover, its surface resistivity did not increase after water washing, while the surface resistivity of the control example sample increased significantly after water washing, which may be due to the loss of surface-precipitated antistatic agent. Compared with Examples 2-4, Example 1 had a different amount of polymeric antistatic agent added. Because the polymeric antistatic agent has a larger molecular weight and forms a network structure in the matrix during compatibility with the matrix, the accumulated charge is released through the conductive path, effectively reducing the volume resistivity of the blend. When the amount added increases, it is beneficial for the polymer to form a continuous network. However, when the amount added is too large, it will aggregate inside the polypropylene, which will make it difficult for it to migrate to the sample surface. Therefore, the decrease in surface resistivity gradually tends to be stable, and this aggregation may further affect the mechanical properties of the sample.

[0070] Test Example 2

[0071] The performance of the samples in the examples and control examples was tested according to the test methods in QB / T3811-1999 "Plastic Straps". The specific results are shown in Table 2.

[0072] Table 2 Performance Test Results of Antistatic Strapping

[0073]

[0074] As can be seen from Table 2, the antistatic packing tape prepared by the present invention has good mechanical properties and is not prone to cracking or breakage during use. However, due to the different amounts of polymer antistatic agent added in the examples, the mechanical properties of the samples are slightly different. Overall, the amount added in Example 1 is relatively optimal.

[0075] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An antistatic packing tape, characterized by comprising: The polypropylene 60~80 parts, the toughening agent 5~10 parts, the lubricant 0.5~2 parts, the antioxidant 1~5 parts and the polymer antistatic agent 4~5 parts by weight are mixed to obtain the mixture. The preparation method of the polymer antistatic agent comprises the following steps: The allyl benzene, N,N,N-trimethyl-2-[(2-methacryl)oxy]propyl-2-ammonium chloride and hydroxymethyl methacrylate are added into anhydrous ethanol, and the initiator is added after stirring and mixing uniformly, the amount of the initiator is 0.5~1wt%, the temperature is increased to 70~80℃, the reaction is carried out for 4~8h, then the volume is evaporated to 1 / 4 of the original volume under reduced pressure, then toluene is added until the precipitation appears, then the mixture is filtered, and the residue is dried to obtain the polymer antistatic agent. The molar ratio of the allyl benzene, N,N,N-trimethyl-2-[(2-methacryl)oxy]propyl-2-ammonium chloride and hydroxymethyl methacrylate is 10:5~10:1~5.

2. The anti-static stretch wrap film of claim 1, wherein, The lubricant is magnesium stearate.

3. The anti-static stretch wrap film of claim 1, wherein, The antioxidant is antioxidant 1010.

4. The anti-static stretch wrap film of claim 1, wherein, The toughening agent is polyethylene octene copolymer elastomer.

5. The anti-static stretch wrap film of claim 1, wherein, The initiator is azobisdimethyl isobutyronitrile.

6. A method of producing the anti-static packing tape as claimed in any one of claims 1 to 5, characterized by, The preparation method comprises the following steps: S1, the polypropylene, the toughening agent, the lubricant, the antioxidant and the polymer antistatic agent are mixed and stirred uniformly to obtain the mixture; S2, the mixture is plasticized and extruded, then cooled, shaped, wound, packaged to obtain the antistatic packaging belt.

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