Dupont paper composite wrapping material

Abstract

The application provides a Dupont paper composite packaging material and relates to the technical field of packaging materials. The Dupont paper composite packaging material comprises Dupont paper, and a reinforcing layer and a liquid blocking layer are sequentially compounded on one side of the Dupont paper from top to bottom. The reinforcing layer is compounded with the Dupont paper, and the reinforcing layer comprises a temperature-resistant agent filler. The Dupont paper composite packaging material can be applied to a high-temperature environment, effectively blocks liquid, reduces the occurrence of reverse osmosis of liquid, and has a certain strength and low cost.

Description

Technical Field

[0001] This application relates to the field of packaging technology, and more specifically, to a DuPont paper composite packaging material. Background Technology

[0002] Desiccants are substances that can adsorb or absorb water vapor from the surrounding environment. Their core function is to reduce humidity in enclosed or semi-enclosed spaces, thereby preventing items from deteriorating, corroding, clumping, or becoming moldy due to moisture. Desiccants are commonly used in long-distance transportation. In scenarios such as ocean shipping containers, the internal temperature can be maintained above 70°C for extended periods, and even reach 110-120°C under instantaneous exposure to sunlight. This can cause the desiccant packaging material to age faster, become brittle, lose strength, and even melt and stick together, leading to a risk of leakage.

[0003] Currently, some packaging materials (especially non-woven fabrics and ordinary composite films) are typically suitable for temperatures below 90°C and are prone to liquid backflow under pressure or high temperature conditions. Meanwhile, some high-strength materials (such as Tyvek®) are expensive. Utility Model Content

[0004] The purpose of this application is to provide a DuPont paper composite packaging material to improve the technical problems of existing packaging materials being unsuitable for high-temperature environments, prone to liquid backflow, and unable to balance strength and cost.

[0005] In a first aspect, embodiments of this application provide a DuPont paper composite packaging material, including DuPont paper, with a reinforcing layer and a liquid-blocking layer sequentially laminated on one side of the DuPont paper from top to bottom. The reinforcing layer is laminated with the DuPont paper, the liquid-blocking layer is used to contact the product to be packaged, and the reinforcing layer contains a heat-resistant filler.

[0006] In the above-described implementation process, this application forms a DuPont paper composite packaging material by sequentially combining DuPont paper, a composite reinforcing layer, and a liquid-blocking layer from top to bottom. DuPont paper inherently possesses certain mechanical strength and good liquid resistance, serving as the basic support for the entire composite material. The liquid-blocking layer also exhibits good liquid resistance. The DuPont paper and the liquid-blocking layer form a dual liquid-blocking structure, thereby synergistically enhancing the strength of the composite packaging material to a certain extent, while maintaining low cost and effectively blocking liquids. In addition, the reinforcing layer contains a heat-resistant filler, which can effectively improve the high-temperature resistance of the composite packaging material, making it suitable for high-temperature environments and effectively blocking liquids, reducing the occurrence of liquid backflow, while maintaining a certain level of strength at a low cost.

[0007] In one possible implementation, the thickness of the reinforcement layer is 12~25 μm.

[0008] This application uses a reinforcing layer of appropriate thickness, which can provide a certain strength and give full play to the advantages of high temperature resistance, while balancing an appropriate cost. Thus, the composite packaging material formed by combining DuPont paper and liquid-resistant layer has both a certain strength and high high temperature resistance, while the cost is low.

[0009] In one possible implementation, the heat-resistant filler accounts for 8% to 35% of the mass percentage of the reinforcing layer.

[0010] The reinforcing layer of this application contains a suitable quality of heat-resistant filler, which can effectively enhance high-temperature resistance while maintaining a certain strength, thus balancing a certain strength and high high-temperature resistance, while also being low in cost.

[0011] In one possible implementation, the heat-resistant filler is one of nano-silica, alumina, aluminum nitride, wollastonite, or polyimide.

[0012] The reinforcing layer of this application contains a heat-resistant filler of suitable material, which can effectively enhance high-temperature resistance and balance a certain strength and low cost.

[0013] In one possible implementation, the thickness of the liquid-blocking layer is 20~60 μm.

[0014] This application uses a liquid-blocking layer of appropriate thickness, which can effectively block liquids while maintaining good air permeability. At the same time, it facilitates the excellent heat-sealing performance of subsequent packaging materials, thereby improving the leak-proof performance of the packaging materials after packaging the products to be packaged.

[0015] In one possible implementation, the reinforcing layer is also coated with a condensation film layer on the side closest to the liquid-blocking layer.

[0016] This application has a condensation film layer coated on the side of the reinforcing layer near the liquid barrier layer, which not only facilitates a stronger bond between the reinforcing layer and the liquid barrier layer, but also has a certain liquid barrier property. It can be combined with DuPont paper, the reinforcing layer and the liquid barrier layer to further assist in blocking liquid and reduce the occurrence of liquid backflow.

[0017] In one possible implementation, the pore density of the reinforcing layer, the condensate layer, and the liquid-blocking layer are all 8 to 60 pores / cm², and the average pore size is 0.3 to 1.2 mm.

[0018] This application sets appropriate pore density and average pore size in the reinforcing layer, condensate layer and liquid barrier layer, so as to make the packaging material formed with DuPont paper have good air permeability while meeting the leakage prevention requirements.

[0019] In one possible implementation, the area mass of DuPont paper is 35~90 g / m².

[0020] This application uses DuPont paper of suitable unit area weight as the base of the entire composite packaging material to achieve a certain mechanical strength, excellent liquid resistance, and a balanced and appropriate cost.

[0021] In one possible implementation, the total thickness of the DuPont paper composite packaging is 35–160 μm.

[0022] The DuPont paper composite packaging material of this application adopts an appropriate total thickness, and on the basis of taking into account an appropriate cost, the composite packaging material has better strength, high temperature resistance and liquid resistance, so as to balance a certain strength and an appropriate cost, while having good high temperature resistance and liquid resistance.

[0023] In one possible implementation, the base material of the reinforcing layer is polyethylene terephthalate.

[0024] The reinforcing layer of this application uses a suitable base material to have certain strength and temperature resistance. At the same time, when mixed with a heat-resistant filler, it can significantly improve the glass transition temperature and heat distortion temperature of the reinforcing layer material, effectively improving the long-term temperature resistance of the reinforcing layer. This allows the reinforcing layer to withstand high-temperature loads, suppressing the thermal shrinkage and deformation of the entire composite packaging material at high temperatures, and maintaining the structural stability of the entire composite packaging material.

[0025] In one possible implementation, the liquid barrier layer is made of low-density polyethylene or linear low-density polyethylene.

[0026] The liquid barrier layer of this application uses a suitable material that can form a double liquid barrier with DuPont paper, thereby facilitating efficient liquid barrier. Furthermore, the suitable material of the liquid barrier layer helps the subsequent packaging material to have excellent heat-sealing performance, thereby improving the leak-proof performance of the packaged product.

[0027] In one possible implementation, the condensation film layer is made of an aqueous acrylic resin containing nanoscale fumed silica.

[0028] The condensation layer of this application uses a suitable material, which not only facilitates a stronger bonding and composite of the reinforcing layer and the liquid-resistant layer, but also has a certain liquid-resistant property and a certain temperature resistance, in order to further improve the high-temperature resistance of the overall composite packaging material. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1This is a cross-sectional view of the DuPont paper composite packaging material provided in Embodiment 1 of this application; Figure 2 This is a cross-sectional view of the DuPont paper composite packaging material provided in Embodiment 3 of this application.

[0031] Icons: 1-DuPont paper; 2-Reinforcing layer; 21-Cloth film layer; 3-Liquid barrier layer. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this application, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] This application aims to address the technical problems of existing packaging materials being unsuitable for high-temperature environments, prone to liquid backflow, and unable to balance strength and cost. It proposes a DuPont paper-based composite packaging material, such as... Figure 2 As shown, it includes DuPont paper 1, with a reinforcing layer 2 and a liquid barrier layer 3 sequentially laminated on one side of the DuPont paper 1 from top to bottom. The reinforcing layer 2 is laminated with the DuPont paper 1. The liquid barrier layer 3 is used to contact the product to be packaged. The reinforcing layer 2 contains a heat-resistant filler.

[0039] The DuPont paper 1, composite reinforcement layer 2, and liquid barrier layer 3 are sequentially laminated from top to bottom to form the DuPont paper 1 composite packaging material. DuPont paper 1 inherently possesses certain mechanical strength and good liquid barrier properties, serving as the foundation support for the entire composite material. Liquid barrier layer 3 also exhibits good liquid barrier properties. DuPont paper 1 and liquid barrier layer 3 form a dual liquid barrier, synergistically enhancing the strength of the composite packaging material at a relatively low cost, while also effectively blocking liquids. Furthermore, reinforcement layer 2 contains a heat-resistant filler, effectively improving the high-temperature resistance of the composite packaging material, making it suitable for high-temperature environments and effectively blocking liquids, reducing backflow, while maintaining a certain level of strength at a low cost. Additionally, the high-temperature resistance of reinforcement layer 2 can suppress thermal shrinkage and deformation of the entire composite packaging material at high temperatures, thus maintaining the stability of the overall composite packaging structure.

[0040] In some embodiments, the thickness of the reinforcing layer 2 is 12-25 μm. For example, the thickness of the reinforcing layer 2 can be, but is not limited to, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, or 25 μm. Using a reinforcing layer 2 of suitable thickness provides a certain level of strength while also offering advantages in high-temperature resistance, balancing a suitable cost. This results in a composite packaging material formed by combining the reinforcing layer 2 with DuPont paper 1 and the liquid-resistant layer 3, possessing both sufficient strength and high high-temperature resistance, while maintaining a low cost.

[0041] In some embodiments, the heat-resistant filler accounts for 8% to 35% of the mass percentage of the reinforcing layer 2. For example, the heat-resistant filler percentage of the reinforcing layer 2 may be, but is not limited to, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, or 35%. The reinforcing layer 2 contains a suitable amount of heat-resistant filler, which can effectively enhance high-temperature resistance while maintaining a certain strength, thus balancing a certain strength with high high-temperature resistance, while also being cost-effective.

[0042] In some embodiments, the heat-resistant filler is one of nano-silica, alumina, aluminum nitride, wollastonite, and polyimide. Specifically, the heat-resistant filler is nano-silica. The reinforcing layer 2 contains a heat-resistant filler of suitable material, which can effectively enhance high-temperature resistance and balance strength and low cost. It should be noted that the reinforcing layer containing the heat-resistant filler is derived from...

[0043] In some embodiments, the thickness of the liquid-blocking layer 3 is 20~60 μm. For example, the thickness of the liquid-blocking layer 3 can be, but is not limited to, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, and 60 μm. Using a liquid-blocking layer 3 of suitable thickness can effectively block liquids while maintaining good air permeability, and also facilitates excellent heat-sealing performance of subsequent packaging materials, thereby improving the leak-proof performance of the packaged product.

[0044] In some embodiments, such as Figure 1 As shown, a condensation layer 21 is also coated on the side of the reinforcing layer 2 closest to the liquid-blocking layer 3. Coating the reinforcing layer 2 with the condensation layer 21 on the side of the reinforcing layer 2 closest to the liquid-blocking layer 3 facilitates a stronger bond between the reinforcing layer 2 and the liquid-blocking layer 3, while also providing some liquid-blocking properties. This allows it to be combined with DuPont paper 1, the reinforcing layer 2, and the liquid-blocking layer 3 to further assist in blocking liquid and reducing backflow. It should be noted that the condensation layer 21 is a thin film formed by curing the material. After bonding the reinforcing layer 2 and the liquid-blocking layer 3, it adheres to the surfaces of the reinforcing layer 2 and the liquid-blocking layer 3, and its thickness is negligible. In some embodiments, the pore density of the reinforcing layer 2, the condensation film layer 21, and the liquid-blocking layer 3 is all 8 to 60 pores / cm², and the average pore size is all 0.3 to 1.2 mm. As an example, the pore density of the reinforcing layer 2, the condensation film layer 21, and the liquid-blocking layer 3 may be, but is not limited to, 8 pores / cm², 10 pores / cm², 12 pores / cm², 15 pores / cm², 18 pores / cm², 20 pores / cm², 22 pores / cm², 25 pores / cm², 28 pores / cm², 30 pores / cm², 32 pores / cm², 35 pores / cm², 38 pores / cm², 40 pores / cm², 42 pores / cm², 45 pores / cm², 48 pores / cm², 50 pores / cm², 52 pores / cm², 55 pores / cm², 58 pores / cm², or 60 pores / cm². The average pore size can be, but is not limited to, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. The reinforcing layer 2, the condensing film layer 21, and the liquid-blocking layer 3 are all provided with suitable pore density and average pore size to ensure good air permeability of the packaging material formed with DuPont paper 1 while meeting leakage prevention requirements. In some embodiments, the pore density and average pore size of the reinforcing layer 2, the condensing film layer 21, and the liquid-blocking layer 3 can be the same. In other embodiments, the pore density and average pore size of the reinforcing layer 2, the condensing film layer 21, and the liquid-blocking layer 3 can also be different. In some embodiments, the spacing between adjacent micropores is the same, and the spacing between adjacent micropores is 1 to 3 mm. As an example, the spacing between adjacent micropores can be, but is not limited to, 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm. Specifically, the spacing between adjacent micropores is 2 mm. In other embodiments, the row spacing between each row of micropores is different from the column spacing between each column of micropores, with the row spacing between each row of micropores being 1-3 mm and the column spacing between each column of micropores being 2-4 mm. In other embodiments, the micropores in adjacent rows are arranged alternately.

[0045] In some embodiments, the area mass of DuPont paper 1 is 35~90 g / m². As an example, the area mass of DuPont paper 1 can be, but is not limited to, 35 g / m², 40 g / m², 45 g / m², 50 g / m², 55 g / m², 60 g / m², 65 g / m², 70 g / m², 75 g / m², 80 g / m², 85 g / m², and 90 g / m². Using DuPont paper 1 with a suitable area mass as the base of the entire composite packaging material provides a certain level of mechanical strength, excellent liquid resistance, and a balanced cost. It should be noted that domestically produced flash-processed high-density polyethylene DuPont paper can be selected, which offers a certain level of mechanical strength and excellent liquid resistance at a lower cost, thereby reducing the overall cost of the composite packaging material.

[0046] In some embodiments, the total thickness of the DuPont Paper 1 composite packaging material is 35~160 μm. As an example, the total thickness of the DuPont Paper 1 composite packaging material can be, but is not limited to, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, 155 μm, and 160 μm. The DuPont Paper 1 composite packaging material employs a suitable total thickness to achieve better strength, high-temperature resistance, and liquid resistance while considering appropriate cost, thus balancing a certain level of strength with a suitable cost, while also possessing good high-temperature resistance and liquid resistance.

[0047] In some embodiments, the base material of the reinforcing layer 2 is polyethylene terephthalate. The reinforcing layer 2 adopts a suitable base material to have certain strength and temperature resistance. Specifically, the material of the reinforcing layer 2 is a blend of PET raw material and nano-silica, which significantly improves the glass transition temperature and heat distortion temperature of the reinforcing layer 2 material, effectively improving the long-term temperature resistance of the reinforcing layer 2, enabling the reinforcing layer 2 to withstand high temperature loads, suppressing the thermal shrinkage and deformation of the entire composite packaging material at high temperatures, and maintaining the structural stability of the entire composite packaging material. Specifically, the reinforcing layer is a composite PET material containing 20% ​​nano-silica (this material is the material disclosed in Fu Hongyan, Zeng Xiaofei, Wang Guoquan, Chen Jianfeng. Study on mechanical properties and crystallization properties of PET / SO2 nanocomposite materials [J]. Journal of Beijing University of Chemical Technology (Natural Science Edition), 2010, 37(2):34-38.).

[0048] In some embodiments, the liquid barrier layer 3 is made of low-density polyethylene or linear low-density polyethylene. The suitable material of the liquid barrier layer 3 allows it to form a double liquid barrier with the DuPont paper 1, thereby facilitating efficient liquid barrier. Furthermore, the suitable material of the liquid barrier layer 3 helps to give the subsequent packaging material excellent heat-sealing properties, thus improving the leak-proof performance of the packaged product.

[0049] In some embodiments, the condensation layer 21 is made of an aqueous acrylic resin containing nano-sized fumed silica. The use of a suitable material for the condensation layer 21 facilitates a stronger bond between the reinforcing layer 2 and the liquid-blocking layer 3, while also providing some liquid-blocking properties and temperature resistance to further improve the overall high-temperature resistance of the composite packaging material. It should be noted that the condensation layer 21 is a thin film formed by curing the aqueous acrylic resin containing nano-sized fumed silica. After the condensation layer 21 is bonded to the reinforcing layer 2 and the liquid-blocking layer 3, it adheres to the surfaces of both layers, and its thickness is negligible. It should also be noted that the aqueous acrylic resin containing nano-sized fumed silica was purchased from Wanhua Chemical's Cryso 6318.

[0050] A suitable thickness of reinforcing layer 2 containing a heat-resistant filler is coated with an aqueous acrylic resin containing nano-sized fumed silica on one side. The liquid-blocking layer 3 is then hot-pressed onto the side of reinforcing layer 2 coated with the aqueous acrylic resin containing nano-sized fumed silica. This process combines good high-temperature resistance and liquid-blocking properties. After hot-pressing, the aqueous acrylic resin containing nano-sized fumed silica cures to form a gel film layer 21, which more firmly bonds the reinforcing layer 2 and the liquid-blocking layer 3 together and further enhances the liquid-blocking performance. Finally, an array of dotted hot melt adhesive is applied to one side of DuPont paper 1, allowing the DuPont paper 1 to bond with the reinforcing layer 2 and the liquid-blocking layer 3 bonded together through the gel film layer 21. The surface of the reinforcing layer 2 is composited with a dotted hot melt adhesive array to form a composite material consisting of DuPont paper 1, composite reinforcing layer 2, condensation film layer 21, and liquid-resistant layer 3 from top to bottom. The reinforcing layer 2, condensation film layer 21, and liquid-resistant layer 3 are then directly punctured with cold needles to form suitable average pore size and pore density. The edges of the pores are then melted and flanged using hot air or infrared instantaneous heating to melt and smooth the burrs, reducing material fuzzing or shedding, and forming smooth pore edges. This creates low-resistance vapor channels with good air permeability. This results in a DuPont paper packaging material that has good air permeability, good high-temperature resistance, liquid resistance, and relatively low cost while maintaining a certain strength.

[0051] Example 1 This embodiment provides a DuPont paper composite packaging material, such as... Figure 1As shown, the product includes DuPont paper (domestic flash-processed high-density polyethylene DuPont paper). A reinforcing layer and a liquid-blocking layer are sequentially laminated from top to bottom on one side of the DuPont paper. The reinforcing layer is laminated with the DuPont paper, and the liquid-blocking layer is used to contact the product to be packaged. The reinforcing layer contains 20% by mass of nano-silica. A condensation film layer is coated on the side of the reinforcing layer closest to the liquid-blocking layer. The DuPont paper has a thickness of 80 μm and a unit area mass of 40 g / m². The reinforcing layer has a thickness of 20 μm, and the liquid-blocking layer has a thickness of 30 μm. The pore density of the reinforcing layer, condensation film layer, and liquid-blocking layer is 25 pores / cm², and the average pore diameter is 0.7 mm. The base material of the reinforcing layer is polyethylene terephthalate, the liquid-blocking layer is linear low-density polyethylene, and the condensation film layer is an aqueous acrylic resin containing nano-sized fumed silica.

[0052] Example 2 This embodiment provides a DuPont paper composite packaging material, such as... Figure 2 As shown, the difference from Example 1 is that the side of the reinforcing layer near the liquid-blocking layer is not coated with a gel film layer, but instead uses a dotted hot melt adhesive array to composite the reinforcing layer and the liquid-blocking layer; the dotted hot melt adhesive array is distributed with adhesive dots having a diameter of 0.5 mm and a spacing of 2 mm.

[0053] Comparative Example This embodiment provides a DuPont paper composite packaging material, which differs from Embodiment 1 in that it does not include a reinforcing layer and a condensation film layer.

[0054] Experimental Example 1 This experimental example involves performance testing of the packaging materials prepared in Examples 1-2 and the comparative example; specifically: High temperature resistance: The test is conducted in accordance with ASTM D2732-14, "Standard Test Method for Free Linear Heat Shrinkage of Plastic Films and Sheets". Each packaging material sample is cut to 100mm×100mm, heated to 260℃ for 30 min, and the length is measured after cooling. The shrinkage rate (%) is calculated as (original length - length after heating) / original length × 100%.

[0055] Liquid resistance: Cover each packaging material sample with the mouth of a container filled with water, apply a pressure of 5 kPa, and check the liquid backflow after 24 hours. Record the amount of water leakage (g).

[0056] Tensile strength: The test was conducted in accordance with ASTM D882, "Standard Test Method for Tensile Properties of Sheets of Plastic". A tensile testing machine was used to stretch each packaging sample at a speed of 50 mm / min. The tensile strength (MPa) at which each packaging sample broke was recorded.

[0057] The results are shown in Table 1.

[0058] Table 1 Packaging Material Performance

[0059] As shown in Table 1, the DuPont paper composite packaging material provided in Example 1 of this application includes DuPont paper, a reinforcing layer, and a liquid-blocking layer arranged sequentially from top to bottom. A gel film layer is coated on the side of the reinforcing layer closest to the liquid-blocking layer. The reinforcing layer contains a heat-resistant filler. The reinforcing layer and the liquid-blocking layer have suitable pore density and average pore size, resulting in low thermal shrinkage under high-temperature conditions and zero liquid leakage over 24 hours, indicating good liquid resistance. It also possesses certain tensile strength and good air permeability. In Example 2, the DuPont paper composite packaging material does not have a gel film layer coated on the side of the reinforcing layer closest to the liquid-blocking layer. Instead, a dotted hot melt adhesive array is used to composite the reinforcing layer and the liquid-blocking layer. Slight liquid leakage occurs over 24 hours; however, the dotted hot melt adhesive array effectively introduces "rivets" between the reinforcing layer and the liquid-blocking layer for toughening, and the dotted bonding reduces stress concentration, thus maintaining high tensile strength.

[0060] This application demonstrates that the DuPont paper composite packaging material provided is suitable for high-temperature environments, effectively blocks liquids, reduces the occurrence of liquid backflow, and has a low cost while maintaining a certain strength.

[0061] Experimental Example 2 In this experimental example, the packaging materials prepared in Examples 1-2 and the comparative example were hot-pressed at 160°C to seal three sides of the DuPont paper composite packaging material, forming a cavity. 10g of magnesium chloride granules were filled into the cavity, and then the cavity was sealed again at 160°C to form a desiccant. The performance of the desiccants prepared from the packaging materials provided in Examples 1-2 and the comparative example was tested; specifically: Leakage amount: Place each desiccant sample on a vibration table and vibrate at a frequency of 10 Hz and an amplitude of 2 mm for 30 min. Collect the released particulate matter and weigh it to record the leakage amount (mg).

[0062] Water absorption rate: The samples that have undergone leakage testing will be subjected to water absorption rate testing. First, weigh each desiccant sample before the test and record the weight as m1. Place each desiccant sample in an environment of 40 ℃ and 90% RH for 72 hours and then weigh it and record the weight as m2. Water absorption rate (%) = (m2-m1) / m1×100. Record the time it takes for the water absorption rate to reach 80%.

[0063] The results are shown in Table 2.

[0064] Table 2 Desiccant Performance

[0065] As shown in Table 2, the desiccant formed by coating desiccant particles with the DuPont paper composite packaging materials provided in Examples 1-2 of this application has a leakage amount of less than 10 mg, meeting the leak-proof requirements. The water absorption rate after 72 hours is all above 80%, demonstrating good air permeability. Furthermore, the time required to reach 80% water absorption is no more than 70 hours, indicating good water absorption efficiency. The DuPont paper composite packaging material provided in the comparative example does not include a reinforcing layer or a condensation layer, and lacks reinforcing layer support. After vibration during the leakage test, micro-cracks of 0.2-0.4 mm appear at the seal. Some MgCl2 absorbs moisture and forms MgCl2·6H2O crystals, further clogging the paper pores. This leads to a sharp drop in the water absorption rate in the middle and later stages. Furthermore, due to the loss of some MgCl2 particles caused by leakage, the water absorption rate is prematurely terminated at 72%.

[0066] This application demonstrates that the DuPont paper composite packaging material provided in this application is used for desiccants, meeting both leak-proof requirements and possessing good air permeability and water absorption efficiency.

[0067] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A DuPont paper composite packaging material, characterized in that, The product includes DuPont paper, on one side of which a reinforcing layer and a liquid-blocking layer are sequentially laminated from top to bottom. The reinforcing layer is laminated with the DuPont paper, and the liquid-blocking layer is used to contact the product to be packaged. The reinforcing layer contains a heat-resistant filler.

2. The DuPont paper composite packaging material according to claim 1, characterized in that, The thickness of the reinforcing layer is 12~25 μm.

3. The DuPont paper composite packaging material according to claim 1 or 2, characterized in that, The heat-resistant filler accounts for 8% to 35% of the mass percentage of the reinforcing layer.

4. The DuPont paper composite packaging material according to claim 3, characterized in that, The heat-resistant filler is one of nano-silica, alumina, aluminum nitride, wollastonite, and polyimide.

5. The DuPont paper composite packaging material according to claim 1, characterized in that, The thickness of the liquid-blocking layer is 20~60 μm.

6. The DuPont paper composite packaging material according to claim 1, characterized in that, The reinforcing layer is also coated with a condensation film layer on the side near the liquid-blocking layer.

7. The DuPont paper composite packaging material according to claim 6, characterized in that, The pore density of the reinforcing layer, the condensation film layer, and the liquid-blocking layer are all 8~60 pores / cm², and the average pore diameter is 0.3~1.2 mm.

8. The DuPont paper composite packaging material according to claim 1, characterized in that, The DuPont paper has a unit area mass of 35~90 g / m².

9. The DuPont paper composite packaging material according to claim 8, characterized in that, The total thickness of the DuPont paper composite packaging material is 35~160 μm.

10. The DuPont paper composite packaging material according to claim 7, characterized in that, The base material of the reinforcing layer is polyethylene terephthalate.

11. The DuPont paper composite packaging material according to claim 7, characterized in that, The liquid-blocking layer is made of low-density polyethylene or linear low-density polyethylene.

12. The DuPont paper composite packaging material according to claim 7, characterized in that, The material of the condensation film layer is an aqueous acrylic resin containing nano-sized fumed silica.

Images