Shielded anti-static ton bag inner liner bag and method of making same

Abstract

The application relates to the technical field of ton bag lining materials, and particularly discloses a shielding and antistatic ton bag lining bag and a preparation method thereof. The shielding and antistatic ton bag lining bag is made of a multilayer composite film with a structure of PET / antistatic layer / PA / PE, and the antistatic layer is made of raw materials containing the following components in parts by weight: resin 40-75 parts; filler 20-40 parts; color master batch 5-10 parts; antistatic agent 1-3 parts; dispersant 2-5 parts; antioxidant 0.2-0.4 parts; polyimide nanofiber 4-6 parts; and modified carbon nanotube 1-3 parts. The modified carbon nanotube is prepared by the following method: S1, pretreating carbon nanotube raw materials with concentrated nitric acid solution to obtain pretreated carbon nanotubes; and S2, dispersing the pretreated carbon nanotubes in dimethylbenzene, adding deionized water and p-toluenesulfonic acid, then adding aniline monomer, and adding ammonium persulfate for reaction, and obtaining the product after the reaction is completed. The shielding and antistatic ton bag lining bag can maintain stable antistatic performance under the influence of an environment with a sharp change in temperature.

Description

Technical Field

[0001] This application relates to the field of ton bag lining materials, and more specifically, it relates to a shielded antistatic ton bag lining and its preparation method. Background Technology

[0002] BOOM (Liquid Unit Bag) is a flexible transport packaging container with advantages such as moisture-proof, dust-proof, radiation-resistant, and robust safety. It also possesses sufficient structural strength. Because BOOMs are easy to load, unload, and handle, their efficiency is significantly improved, leading to rapid development in recent years. BOOMs typically have an inner liner bag inside, which enhances their load-bearing capacity, ensuring the safety of goods during transportation or storage and protecting them from external environmental contamination and damage.

[0003] The inner lining of ton bags is typically made of multiple co-extruded materials. Common materials for ton bag inner linings include multi-layer composite materials such as PET / Al / PA / PE, PA / Al / PE, PET / Al / PE, and PET / PA / PE. These materials combine the advantages of different materials through a composite process, resulting in a soft feel and low cost, making the inner lining widely applicable. Because ton bag inner linings are prone to static electricity, they can attract powdery substances during production, reducing the quality of the inner lining. Therefore, antistatic agents are added to address this issue. Currently, antistatic functionality is achieved through two methods: internal addition and external coating. Internal addition involves adding antistatic components to the inner lining, while external coating involves applying an antistatic agent to the outer layer of the inner lining.

[0004] Regarding the aforementioned technologies, the inventors believe that the inner lining of the ton bag is subject to drastic temperature changes during application. These drastic temperature changes can affect the migration and diffusion of antistatic agent molecules and may alter the molecular structure of the antistatic agent, leading to a significant loss in the antistatic performance of the inner lining of the ton bag. The overall application stability still needs to be improved.

[0005] Therefore, there is an urgent need to propose a solution to address the aforementioned technical problems. Summary of the Invention

[0006] In order to ensure that the antistatic properties of the inner liner of a ton bag can remain excellent and stable under the influence of drastic temperature changes, this application provides a shielded antistatic ton bag inner liner and its preparation method.

[0007] In a first aspect, this application provides a shielded antistatic ton bag liner, which adopts the following technical solution:

[0008] A shielded antistatic ton bag liner is made of a multi-layer composite film with a structure of PET / antistatic layer / PA / PE, wherein the antistatic layer is made of raw materials comprising the following parts by weight:

[0009] 40-75 parts of resin;

[0010] 20-40 parts of filler;

[0011] 5-10 parts of color masterbatch;

[0012] 1-3 parts antistatic agent;

[0013] 2-5 parts dispersant;

[0014] Antioxidant 0.2-0.4 parts;

[0015] 4-6 parts of polyimide nanofibers;

[0016] 1-3 parts of modified carbon nanotubes;

[0017] The modified carbon nanotubes were prepared by the following method:

[0018] S1. Take carbon nanotube raw material and place it in concentrated nitric acid solution. After ultrasonic dispersion, it is then subjected to high-temperature reflux, vacuum filtration and drying to obtain pretreated carbon nanotubes.

[0019] S2. Disperse the pretreated carbon nanotubes obtained in step S1 in xylene, then add deionized water and p-toluenesulfonic acid to obtain a microemulsion; then add aniline monomer to the microemulsion under ice bath conditions, mix evenly, and then add ammonium persulfate to react. After the reaction is completed, filter, wash and dry to obtain modified carbon nanotubes.

[0020] By employing the above technical solution, modified carbon nanotubes are obtained by grafting polyaniline onto the surface of acidified carbon nanotubes. This results in excellent compatibility and dispersibility within the antistatic layer, as well as good interfacial bonding with the resin. Furthermore, by forming a conductive network, the modified carbon nanotubes can work in conjunction with the antistatic agent to exert excellent antistatic properties. Utilizing their excellent structural stability and thermal conductivity under varying temperature conditions, they can provide thermally coordinated protection against the antistatic agent, thus leading to excellent and stable antistatic performance. Meanwhile, polyimide nanofibers exhibit outstanding resistance to temperature changes, maintaining their mechanical properties over extreme temperature ranges and inhibiting changes in the molecular structure of the antistatic agent. Furthermore, under the influence of drastic temperature changes, it can improve the stability of antistatic performance to a certain extent. At the same time, polyimide nanofibers and modified carbon nanotubes can also exert excellent synergistic effects. The entanglement of modified carbon nanotubes by polyimide nanofibers provides structural support and adhesion protection. When carbon nanotubes form a conductive network to exert excellent antistatic effect and thermal coordination, they are less likely to be damaged by other raw material mixed matrix in the antistatic layer. This allows the antistatic layer to exert excellent antistatic performance. As a result, under the influence of drastic temperature changes, the antistatic performance of the shielded antistatic ton bag liner can maintain excellent and stable performance, and the overall application effect is significantly improved.

[0021] Preferably, in step S2, the weight ratio of pretreated carbon nanotubes to aniline monomers is 1:(4-6).

[0022] By adopting the above technical solution, when the pretreated carbon nanotubes and aniline react in step S2 at the above weight ratio, polyaniline can be grafted onto the surface of the carbon nanotubes more uniformly. This makes the conductive network formed between the modified carbon nanotubes stronger during application, and also enhances their own stability and thermal coordination protection under the influence of drastic temperature changes. Consequently, the antistatic layer can play its role more stably, which is beneficial to obtaining a shielded antistatic ton bag liner with better application stability.

[0023] Preferably, the weight ratio of the polyimide nanofibers to the modified carbon nanotubes is 5:3.

[0024] By adopting the above technical solution, when polyimide nanofibers and modified carbon nanotubes in the above weight ratio are used together, the compounding effect between them is excellent, enabling the antistatic layer to exert excellent and stable antistatic performance under the influence of drastic temperature changes, and ultimately resulting in a shielded antistatic ton bag inner liner with better application quality.

[0025] Preferably, the polyimide nanofibers have a diameter of 30-80 nm and a length of 6-10 μm; the carbon nanotube raw material has a diameter of 10-15 nm and a length of 1-2 μm.

[0026] By adopting the above technical solution, when the heavy-duty polyimide nanofibers and modified carbon nanotubes are used together, the synergistic effect is excellent. Both the conductive network formed between the modified carbon nanotubes and the entanglement between the polyimide nanofibers and modified carbon nanotubes are evenly distributed and interact completely. As a result, the antistatic layer exhibits excellent antistatic stability under the influence of drastic temperature changes, and a shielded antistatic ton bag liner with good application stability can be obtained.

[0027] Preferably, the raw material of the antistatic layer also contains 2-5 parts by weight of porous alumina.

[0028] By adopting the above technical solution, porous alumina has excellent thermal conductivity. Based on its own porous characteristics, when applied in the antistatic layer, polyimide nanofibers and modified carbon nanotubes can partially enter the porous structure of porous alumina and form a network structure with porous alumina as the connecting node. This significantly improves stability and thermal coordination protection, avoids large thermal differences inside the antistatic layer under the influence of drastic temperature changes, and thus significantly improves the stability of the antistatic layer during application, thereby improving the overall application quality of the shielding antistatic ton bag liner.

[0029] Preferably, the porous alumina has a particle size of 300-500 nm, an average pore size of 100-200 nm, and a porosity of 30-50%.

[0030] By adopting the above technical solution, the porous alumina of the above specifications has a better effect when combined with polyimide nanofibers and modified carbon nanotubes. It also significantly improves the stability of the antistatic layer under the influence of drastic temperature changes, and the final shielded antistatic ton bag liner has better application quality.

[0031] Preferably, the dispersant is one or a combination of several of the following: stearamide, hexenyl bis-stearamide, glyceryl monostearate, glyceryl tristearate, microcrystalline wax, barium stearate, zinc stearate, calcium stearate, ethylene-acrylic acid copolymer, and ethylene-vinyl acetate copolymer.

[0032] By adopting the above technical solutions, the dispersant can ensure that the raw materials of each component are fully dispersed and combined, avoid agglomeration, and improve the processing performance of the antistatic layer, so that the raw materials used can play an excellent role. The above-mentioned dispersants are all suitable for the preparation of antistatic layers and can play the above-mentioned excellent role.

[0033] Preferably, the antioxidant is one or a combination of several of di-tert-butylphenol, triphenyl phosphate, o-phenylenediamine, and catechol.

[0034] By adopting the above technical solutions, antioxidants can effectively inhibit or reduce the rate of thermal oxidation reaction of resin macromolecules and delay the thermal and oxygen degradation process of resin, thereby significantly improving the heat resistance of resin. This helps to maintain the stability of the antistatic layer under the influence of drastic temperature changes. All of the above-mentioned antioxidants are suitable for the preparation of antistatic layers and can exert the above-mentioned excellent effects.

[0035] Secondly, this application provides a method for preparing a shielded antistatic ton bag liner, which adopts the following technical solution:

[0036] A method for preparing a shielded antistatic ton bag liner includes the following steps:

[0037] (1) Prepare raw materials containing resin, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube according to the formula;

[0038] (2) After uniformly mixing the resin material, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube in step (1), the mixture is extruded and granulated to obtain the antistatic layer material.

[0039] (3) Take the antistatic layer material obtained in step (2) and PET, PA and PE and perform four-layer co-extrusion blow molding to obtain a multi-layer composite film with the structure of PET / antistatic layer / PA / PE. Then, after bag making, a shielded antistatic ton bag liner is obtained.

[0040] By adopting the above technical solution, the above preparation method is simple to operate. In the preparation process of antistatic layer material, the raw materials are processed in one pot, which can ensure that the interaction between the raw materials can be well played, and the overall performance is better. It can finally obtain a shielding antistatic ton bag liner with excellent and stable quality, and it is also suitable for large-scale industrial production.

[0041] In summary, this application has the following beneficial effects:

[0042] 1. This application utilizes polyimide nanofibers and modified carbon nanotubes in the antistatic layer, and through the synergistic effect of their combination, it can exert excellent thermal coordination and electrostatic protection, enabling the antistatic layer to exhibit excellent antistatic performance. Consequently, under the influence of environments with drastic temperature changes, the antistatic performance of the shielding antistatic ton bag liner can maintain excellent and stable performance, significantly improving the overall application effect.

[0043] 2. This application utilizes porous alumina and leverages the excellent combination effect between porous alumina, polyimide nanofibers, and modified carbon nanotubes to achieve a synergistic enhancement effect, thereby significantly improving the stability of the antistatic layer during application and enhancing the overall application quality of the shielded antistatic ton bag liner. Detailed Implementation

[0044] The present application will be further described in detail below with reference to preparation examples, embodiments and comparative examples.

[0045] Unless otherwise specified, all raw materials used in the preparation examples, embodiments, and comparative examples of this application are commercially available.

[0046] The metallocene linear polyolefin resin was purchased from MVLDPE (metallocene) Pryman Japan SP0540.

[0047] Low-density polyethylene resin was purchased from Qatar Petrochemical LA0710;

[0048] The color masterbatch was purchased from Jinan Dahua Plastics Processing Plant as black masterbatch;

[0049] The antistatic agent was purchased from Croda Antistatic Agent 129V in the UK.

[0050] Preparation examples of raw materials and / or intermediates

[0051] Preparation Example 1

[0052] A modified carbon nanotube was prepared by the following method:

[0053] S1. Take carbon nanotube raw material and place it in concentrated nitric acid solution with a material-to-liquid ratio of 1g:20mL. After ultrasonic dispersion for 30min, reflux at 110℃ for 1h and filter and dry to obtain pretreated carbon nanotubes.

[0054] S2. Disperse the pretreated carbon nanotubes obtained in step S1 in xylene, then add deionized water and p-toluenesulfonic acid. The weight ratio of pretreated carbon nanotubes, xylene, deionized water and p-toluenesulfonic acid is 0.1:20:60:2 to obtain a microemulsion. Then, under ice bath conditions, add aniline monomer to the microemulsion, mix evenly, and then add ammonium persulfate solution with a mass fraction of 0.03 g / mL to react. The mixing ratio of aniline monomer and ammonium persulfate solution is 1 g:80 mL. After the reaction is completed, filter, wash and dry to obtain modified carbon nanotubes.

[0055] Note: In step S2, the weight ratio of pretreated carbon nanotubes to aniline monomers is 1:5; the diameter of the carbon nanotube raw material is 12.5 nm and the length is 1.5 μm.

[0056] Preparation Example 2

[0057] A modified carbon nanotube differs from preparation example 1 in that, in step S2, the weight ratio of pretreated carbon nanotubes to aniline monomer is 1:4.

[0058] Preparation Example 3

[0059] A modified carbon nanotube differs from preparation example 1 in that, in step S2, the weight ratio of pretreated carbon nanotubes to aniline monomer is 1:6.

[0060] Preparation Example 4

[0061] A modified carbon nanotube, which differs from Preparation Example 1 in that the carbon nanotube raw material has a diameter of 10 nm and a length of 1 μm.

[0062] Preparation Example 5

[0063] A modified carbon nanotube, which differs from Preparation Example 1 in that the carbon nanotube raw material has a diameter of 15 nm and a length of 2 μm.

[0064] Example

[0065] Example 1

[0066] A shielded antistatic ton bag liner is made from a multi-layer composite film with a structure of PET / antistatic layer / PA / PE. The raw materials used to prepare the antistatic layer and their corresponding weights are shown in Table 1. The shielded antistatic ton bag liner is prepared through the following steps:

[0067] (1) Prepare raw materials containing resin, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube according to the formula;

[0068] (2) After uniformly mixing the resin material, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube in step (1), the mixture is extruded and granulated to obtain the antistatic layer material.

[0069] (3) Take the antistatic layer material obtained in step (2) and PET, PA and PE and perform four-layer co-extrusion blow molding to obtain a multi-layer composite film with the structure of PET / antistatic layer / PA / PE. Then, after bag making, a shielded antistatic ton bag liner is obtained.

[0070] Note: In the above operation, the resin material is composed of metallocene linear polyolefin resin and low-density polyethylene resin in a weight ratio of 3:2; the filler is talc; the dispersant is stearamide; the antioxidant is di-tert-butylphenol; the polyimide nanofibers have a diameter of 55 nm and a length of 8 μm; and the modified carbon nanotubes were obtained in Preparation Example 1.

[0071] Example 2-3

[0072] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the raw materials used to prepare the antistatic layer and their corresponding weights are shown in Table 1.

[0073] Table 1. Raw materials and their weight percentages (kg / part) used in the preparation of the antistatic layer in Examples 1-3.

[0074] raw material Example 1 Example 2 Example 3 resin material 57.5 40 75 filler 30 20 40 Masterbatch 7.5 5 10 Antistatic agent 2 1 3 dispersant 3.5 2 5 antioxidants 0.3 0.2 0.4 Polyimide nanofibers 5 4 6 Modified carbon nanotubes 2 1 3

[0075] Example 4

[0076] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the polyimide nanofibers have a diameter of 30 nm and a length of 6 μm.

[0077] Example 5

[0078] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the polyimide nanofibers have a diameter of 80 nm and a length of 10 μm.

[0079] Example 6

[0080] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the modified carbon nanotubes are obtained in Preparation Example 2.

[0081] Example 7

[0082] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the modified carbon nanotubes are obtained in Preparation Example 3.

[0083] Example 8

[0084] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the modified carbon nanotubes are obtained in Preparation Example 4.

[0085] Example 9

[0086] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the modified carbon nanotubes are obtained in Preparation Example 5.

[0087] Example 10

[0088] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the raw material of the antistatic layer also contains 3.5 parts by weight of porous alumina, and the porous alumina is added together with other raw materials in step (2); wherein, the porous alumina has a particle size of 400nm, an average pore size of 150nm, and a porosity of 40%.

[0089] Example 11

[0090] A shielded antistatic ton bag liner bag, which differs from Example 10 in that the porous alumina added is 2 parts by weight.

[0091] Example 12

[0092] A shielded antistatic ton bag liner bag, which differs from Example 10 in that the porous alumina added is 5 parts by weight.

[0093] Example 13

[0094] A shielded antistatic ton bag liner bag, which differs from Example 10 in that the porous alumina has a particle size of 300 nm, an average pore size of 100 nm, and a porosity of 30%.

[0095] Example 14

[0096] A shielded antistatic ton bag liner bag, which differs from Example 10 in that the porous alumina has a particle size of 500 nm, an average pore size of 200 nm, and a porosity of 50%.

[0097] Example 15

[0098] A shielded antistatic ton bag liner bag differs from Example 1 in that the total amount of polyimide nanofibers and modified carbon nanotubes remains unchanged, but the weight ratio of the two is adjusted to 5:3.

[0099] Comparative Example

[0100] Comparative Example 1

[0101] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the antistatic layer does not use polyimide nanofibers in its raw material.

[0102] Comparative Example 2

[0103] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the antistatic layer does not use modified carbon nanotubes in its raw material.

[0104] Comparative Example 3

[0105] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the antistatic layer does not use polyimide nanofibers and modified carbon nanotubes in its raw materials.

[0106] Comparative Example 4

[0107] A shielded antistatic ton bag liner bag, which differs from Example 1 in that the modified carbon nanotubes are replaced with carbon nanotube raw materials.

[0108] Comparative Example 5

[0109] A shielded antistatic ton bag liner bag, which differs from Comparative Example 1 in that the modified carbon nanotubes are replaced with carbon nanotube raw materials.

[0110] Comparative Example 6

[0111] A shielded antistatic ton bag liner bag, which differs from Example 10 in that the antistatic layer does not use polyimide nanofibers and modified carbon nanotubes in its raw materials.

[0112] Performance testing test samples: The shielded antistatic ton bag liner obtained in Examples 1-15 was used as test samples 1-15, and the shielded antistatic ton bag liner obtained in Comparative Examples 1-6 was used as control samples 1-6; wherein, the size of the shielded antistatic ton bag liner is 1.2m×1.2m×1.5m, and the thickness of each layer of its structure PET / antistatic layer / PA / PE is 15μm, 30μm, 20μm, and 100μm, respectively.

[0113] Test method: For the inner lining of the shielded antistatic ton bag, the test was conducted according to the method in GB / T 14447-1993 "Test Method for Electrostatic Properties of Plastic Films - Half-life Method" to obtain the half-life time, which is denoted as T1;

[0114] The principle of charge half-life testing is to measure the time required for the surface potential of a thin film to decay to half of its initial value over time in an electrostatic field. The shorter the half-life, the faster the static electricity dissipates, indicating better antistatic performance.

[0115] Then, the inner liner of the shielded ton bag was placed in a high and low temperature alternating test chamber with an initial temperature of 25℃. The temperature was first increased to 80℃ at 3℃ / min, then decreased to -20℃ at 1.5℃ / min, and then increased to 25℃ at 2℃ / min. This was recorded as 1 cycle. After 20 cycles, the half-life time was obtained by testing according to the above method and recorded as T2.

[0116] Finally, the growth rate of the half-life time is calculated as follows: growth rate of half-life time = (T2-T1) / T1. The larger the growth rate of the half-life time, the worse the stability of the shielded antistatic ton bag liner under the influence of temperature changes.

[0117] Following the above method, after testing the test samples 1-15 and the control samples 1-6 in sequence, the experimental results are recorded in Table 2.

[0118] Table 2 Test results of test samples 1-15 and control samples 1-6

[0119] sample Growth rate of half-life (%) Test sample 1 3.2 Test sample 2 4.1 Test sample 3 3.8 Test sample 4 4.0 Test sample 5 3.7 Test sample 6 3.9 Test sample 7 3.6 Test sample 8 4.2 Test sample 9 3.5 Test sample 10 1.1 Test sample 11 1.5 Test sample 12 1.4 Test sample 13 1.6 Test sample 14 1.3 Test sample 15 2.8 Control sample 1 10.9 Control sample 2 12.8 Control sample 3 15.6 Control sample 4 8.9 Control sample 5 11.7 Control sample 6 14.2

[0120] Based on Examples 1-3 and Comparative Examples 1-3, and in conjunction with Table 2, it can be seen that the use of polyimide nanofibers and modified carbon nanotubes in the antistatic layer can significantly improve the antistatic stability of the shielded antistatic ton bag liner. In the above tests, after undergoing drastic stability changes, the growth rate of the half-life time was relatively low, showing excellent performance. However, if either polyimide nanofibers or modified carbon nanotubes are used alone, although they can improve the antistatic stability, the improvement is limited, and the sum of the improvement effects brought by using them alone is far less than the improvement effect brought by the combination of the two. Therefore, it can be seen that the combination of polyimide nanofibers and modified carbon nanotubes can play an excellent synergistic role. Combined with Comparative Examples 4-5 and Table 2, it can be seen that if the modified carbon nanotubes are replaced with carbon nanotube raw materials, the growth rate of the tested half-life time will increase significantly. Moreover, the combination of carbon nanotube raw materials and polyimide nanofibers can only bring about a simple superposition of effects, and cannot exert an excellent compound synergistic effect. It can be seen that the use of modified carbon nanotubes can exert a more significant effect with polyimide nanofibers, thereby improving the antistatic stability of the shielded antistatic ton bag liner.

[0121] Combining Examples 1 and 4-9 with Table 2, it can be seen that in the preparation of modified carbon nanotubes, controlling the weight ratio of pretreated carbon nanotubes to aniline monomers to be 1:(4-6), and selecting carbon nanotube raw materials with a diameter of 10-15 nm and a length of 1-2 μm, the resulting modified carbon nanotubes all exhibit excellent and stable performance. Simultaneously, polyimide nanofibers with a diameter of 30-80 nm and a length of 6-10 μm can also form excellent synergy with the modified carbon nanotubes, enabling the antistatic layer to exhibit excellent and stable antistatic properties under the influence of drastic temperature changes, ultimately resulting in shielded antistatic ton bag liner bags with better application quality. Specifically, when the weight ratio of polyimide nanofibers to modified carbon nanotubes is 5:3, it is beneficial to obtain shielded antistatic ton bag liner bags with better application stability.

[0122] Combining Examples 1 and 10-14 with Table 2, it can be seen that the addition of porous alumina can further improve the antistatic stability of the antistatic layer under the influence of drastic temperature changes, and the growth rate of the half-life time obtained by testing is also further reduced. Furthermore, combining Comparative Examples 2 and 6 with Table 2, it can be seen that if polyimide nanofibers and modified carbon nanotubes are lacking in the antistatic layer, the improvement effect brought by porous alumina will be greatly reduced. This indicates that porous alumina has a synergistic effect with polyimide nanofibers and modified carbon nanotubes, thereby significantly improving the application stability of the antistatic ton bag liner.

[0123] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A shielded antistatic ton bag inner liner, characterized in that, It is made from a multilayer composite film with a structure of PET / antistatic layer / PA / PE, wherein the antistatic layer is made from raw materials comprising the following parts by weight: 40-75 parts of resin; 20-40 parts of filler; 5-10 parts of color masterbatch; 1-3 parts antistatic agent; 2-5 parts dispersant; Antioxidant 0.2-0.4 parts; 4-6 parts of polyimide nanofibers; 1-3 parts of modified carbon nanotubes; The modified carbon nanotubes were prepared by the following method: S1. Take carbon nanotube raw material and place it in concentrated nitric acid solution. After ultrasonic dispersion, it is then subjected to high-temperature reflux, vacuum filtration and drying to obtain pretreated carbon nanotubes. S2. Disperse the pretreated carbon nanotubes obtained in step S1 in xylene, then add deionized water and p-toluenesulfonic acid to obtain a microemulsion; then add aniline monomer to the microemulsion under ice bath conditions, mix evenly, and then add ammonium persulfate to react. After the reaction is completed, filter, wash and dry to obtain modified carbon nanotubes. The antistatic agent was purchased from Croda Antistatic Agent 129V in the UK; The resin material is composed of metallocene linear polyolefin resin and low-density polyethylene resin in a weight ratio of 3:

2. The filler is talc.

2. The shielded antistatic ton bag liner according to claim 1, characterized in that: In step S2, the weight ratio of pretreated carbon nanotubes to aniline monomers is 1:(4-6).

3. The shielded antistatic ton bag liner according to claim 1, characterized in that: The weight ratio of the polyimide nanofibers to the modified carbon nanotubes is 5:

3.

4. The shielded antistatic ton bag liner according to claim 1, characterized in that: The polyimide nanofibers have a diameter of 30-80 nm and a length of 6-10 μm; the carbon nanotube raw material has a diameter of 10-15 nm and a length of 1-2 μm.

5. The shielded antistatic ton bag liner according to claim 1, characterized in that: The raw material of the antistatic layer also contains 2-5 parts by weight of porous alumina.

6. The shielded antistatic ton bag liner according to claim 5, characterized in that: The porous alumina has a particle size of 300-500 nm, an average pore size of 100-200 nm, and a porosity of 30-50%.

7. The shielded antistatic ton bag liner according to claim 1, characterized in that: The dispersant is one or a combination of several of the following: stearamide, hexenyl bis-stearamide, glyceryl monostearate, glyceryl tristearate, microcrystalline wax, barium stearate, zinc stearate, calcium stearate, ethylene-acrylic acid copolymer, and ethylene-vinyl acetate copolymer.

8. The shielded antistatic ton bag liner according to claim 1, characterized in that: The antioxidant is one or a combination of several of the following: di-tert-butylphenol, triphenyl phosphate, o-phenylenediamine, and catechol.

9. The method for preparing the shielded antistatic ton bag liner as described in claim 1, characterized in that: Includes the following steps: (1) Prepare raw materials containing resin, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube according to the formula; (2) After the resin, filler, color masterbatch, antistatic agent, dispersant, antioxidant, polyimide nanofiber and modified carbon nanotube in step (1) are mixed evenly, they are extruded and granulated to obtain antistatic layer material; (3) Take the antistatic layer material obtained in step (2) and PET, PA and PE and perform four-layer co-extrusion blow molding to obtain a multi-layer composite film with the structure of PET / antistatic layer / PA / PE. Then, after bag making, a shielded antistatic ton bag liner is obtained.