A desiccant packaging material

Abstract

The present application relates to a kind of desiccant packaging materials, the packaging material includes the barrier substrate layer, intermediate layer, heat-seal layer of laminated arrangement;The thickness of barrier substrate layer is 0.010-0.032mm;Barrier substrate layer is at 30 DEG C, 90%RH, moisture permeability is 2-100g·(m 2 ·24h) ‑1 ;The thickness of the intermediate layer is 0.035-0.23mm, grammage is 8.0-56.0g / m 2 , air permeation is 55~6500L / m 2 s;The thickness of heat-seal layer is 0.01-0.06mm, material includes at least one of polyethylene, polypropylene, and heat-seal layer is provided with through hole, porosity is 0.01-30%, the average pore size of the through hole is 0.05-0.75mm.The desiccant packaging material of the present application considers low moisture permeability, light transmittance, barrier dustproof and high service life, and the expansion degree of the dry bag made is small when heated.

Description

Technical Field

[0001] This invention belongs to the field of thin film materials technology, and specifically relates to a desiccant packaging material. Background Technology

[0002] As video surveillance cameras and car headlights are used for longer periods, moisture from the external environment can seep into them, affecting the clarity of the surveillance footage, reducing headlight brightness, and causing glare, thus compromising driving safety.

[0003] Existing desiccant packaging materials generally aim for higher moisture permeability and faster drying speeds. For example, patent application CN107225826A discloses a desiccant packaging material comprising a PE film, a breathable film, and a fabric base material. The breathable film is bonded to the inner surface of the fabric base material with an adhesive, and the PE film is bonded to the inner surface of the breathable film with an adhesive. The PE film has several through-holes for ventilation. However, this material is only suitable for food applications and cannot be used in special occasions. Patent CN212147826U discloses a waterproof, high-permeability film that facilitates moisture regulation, comprising a first non-woven fabric layer, a polypropylene high-permeability film, and a linear low-density polyethylene layer bonded sequentially. The high-permeability film and the polyethylene layer have microporous structures and through-holes, respectively. While this material can be used in the food desiccant field, it also cannot meet the requirements of special occasions.

[0004] For desiccants used in video surveillance cameras and automotive headlights, there are even higher requirements for moisture permeability. When the moisture permeability of the desiccant packaging material is too low, it can only absorb moisture slowly, resulting in more moisture seeping in from the outside than being absorbed by the desiccant. This causes the humidity inside the device cavity to rise, reducing the humidity difference between the inside and outside. This results in a balance between the moisture seeping in from the outside and the limited moisture absorbed by the desiccant, leading to an even greater increase in humidity inside the device cavity. This can cause the device to fog up easily during use, resulting in unclear video surveillance cameras, significantly reduced monitoring effectiveness, or reduced headlight brightness, affecting driving safety.

[0005] When the moisture permeability of the desiccant packaging material is too high, the desiccant will quickly absorb moisture, and the amount of moisture that seeps in from the outside will be less than the amount absorbed by the desiccant. As a result, the humidity inside the equipment cavity decreases, and the humidity difference between it and the outside increases, so that the moisture that seeps in from the outside is balanced with the moisture absorbed by the desiccant. When the humidity inside the equipment cavity decreases, the equipment is very unlikely to fog up during use, and the effect is excellent. However, at this time, the desiccant also absorbs more moisture from the outside due to the increased humidity difference between the inside and outside in the same amount of time. Although it can dry quickly, the desiccant's drying performance is consumed quickly, and its lifespan is shortened, requiring timely replacement. However, most video surveillance cameras are installed at high altitudes, making desiccant replacement difficult, impractical and uneconomical. As for vehicle lights, replacement is expensive and inconvenient to replace frequently.

[0006] In summary, for desiccants used in video surveillance lenses and automotive headlights, the degree of humidity control within the device's internal cavity is related to the moisture permeability data of the desiccant packaging material, the moisture permeability data of the device's casing, and the average humidity of the external environment. Conventional desiccant packaging materials are not suitable for the scenarios of video surveillance lenses and automotive headlights.

[0007] Currently, the desiccant packaging materials commonly used in video surveillance lenses and automotive lights primarily consist of a multi-layered composite transparent plastic film structure. Their moisture permeability is achieved through perforations in the transparent film. However, this design has a significant drawback: due to the presence of these perforations, the desiccant, after powdering, easily leaks through the holes, affecting the operation of the surveillance equipment and automotive lights. Another common packaging material uses breathable membranes. These membranes typically achieve their breathability by adding fillers such as calcium carbonate to polyethylene (PE) or polypropylene (PP) particles, or by employing a special stretching process. However, these breathable membranes are generally opaque, making it impossible to visually determine whether the desiccant needs replacement. This results in expired desiccants not being replaced in time, reducing their drying effectiveness.

[0008] Because irreversible desiccants (such as quicklime and phosphorus pentoxide) react violently and release heat, and cannot be regenerated by simple physical means, existing desiccants generally use reversible desiccants that can desorb moisture by heating. In high-temperature environments, the water absorbed by the desiccant desorbs and generates water vapor. Due to the large amount of water vapor generated in a short time, there is competition for water vapor to escape, and the movement of water vapor cannot be as smooth as when it enters the drying bag. In addition, the drying bag is not completely filled with desiccant and contains some gases (oxygen, nitrogen, carbon dioxide). The water vapor and gases cause the drying bag to bulge, causing other devices in the small, enclosed space to shift, affecting the normal use of video surveillance or vehicle lights. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to overcome at least one of the above-mentioned technical defects of existing conventional desiccant packaging materials and to provide a desiccant packaging material.

[0010] This invention provides the following technical solution:

[0011] A desiccant packaging material, characterized in that the desiccant packaging material is used in camera equipment or vehicle lights, and the desiccant packaging material comprises a barrier substrate layer, an intermediate layer, and a heat-sealing layer stacked together;

[0012] The thickness of the barrier substrate layer is 0.010-0.032 mm;

[0013] The barrier substrate layer has a moisture permeability of 2-100 g·(m³) at 30°C and 90% RH.2 ·24h) -1 ;

[0014] The thickness of the intermediate layer is 0.035-0.23 mm, and the basis weight is 8.0-56.0 g / m³. 2 Air permeability is 55~6500L / m 2 s;

[0015] The thickness of the heat-sealing layer is 0.01-0.06 mm;

[0016] The heat-sealing layer is made of at least one of polyethylene and polypropylene.

[0017] The heat-sealing layer has through holes, the porosity of the heat-sealing layer is 0.01-30%, and the average pore size of the through holes is 0.05-0.75 mm.

[0018] The technical solution of this invention has the following advantages:

[0019] The desiccant packaging material claimed in this invention has excellent barrier properties through the synergistic effect of the barrier substrate layer, the intermediate layer, and the heat-sealing layer, which can prevent desiccant leakage. In the parallel direction of the packaging material, due to the suitable loose and porous structure of the specific material of the intermediate layer, gas and water vapor can escape from the side of the intermediate layer, avoiding excessive expansion and bulging of the desiccant bag. This makes the desiccant bag suitable for use in specific scenarios such as camera equipment, such as video surveillance lenses, and vehicle lights. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the desiccant packaging material of Example 1;

[0022] Figure 2 This is a structural diagram of the desiccant packaging material in Comparative Example 1.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1-Barrier substrate layer; 2-Intermediate layer; 3-Heat-sealing layer. Detailed Implementation

[0025] In this invention, polyethylene terephthalate corresponds to PET, stretched polypropylene corresponds to OPP, polyamide corresponds to PA, the polyethylene corresponds to PE, and cast polypropylene corresponds to CPP.

[0026] In a preferred embodiment, the desiccant packaging material has a moisture permeability of 2.0-80.0 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 Preferably, it is 5.0-70.0 g·(m 2 ·24h) -1 More preferably, it is 7.0-60.0 g·(m 2 ·24h) -1 The optimal value is 8.0-50.0 g·(m 2 ·24h) -1 It can also be specifically 10 g·(m 2 ·24h) -1 12 g·(m 2 ·24h) -1 15 g·(m 2 ·24h) -1 20 g·(m 2 ·24h) -1 25 g·(m 2 ·24h) -1 30 g·(m 2 ·24h) -1 35 g·(m 2 ·24h) -1 40 g·(m 2 ·24h) -1 45 g·(m 2 ·24h) -1 50 g·(m 2 ·24h) -1 55 g·(m 2 ·24h) -1 The inventors discovered that controlling the overall moisture permeability of packaging materials within a suitable range can ensure that the humidity inside special equipment is maintained at an appropriate ratio. This ensures the normal operation of the equipment, avoids excessive humidity affecting its normal operation, and prevents the desiccant from absorbing moisture too quickly, thus reducing its lifespan.

[0027] In a preferred embodiment, the porosity of the heat-sealing layer is 0.5-18%, preferably 1-15%, and can specifically be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, and 14%, etc. The average pore size of the through holes is 0.1-0.5 mm, and can specifically be 0.2 mm, 0.3 mm, 0.4 mm, etc. The porosity and pore size of the heat-sealing layer can be used to adjust the overall air permeability and moisture permeability of the packaging material.

[0028] In a preferred embodiment, the thickness of the barrier substrate layer is 0.012-0.025 mm, specifically 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm, 0.020 mm, 0.021 mm, 0.022 mm, 0.023 mm, and 0.024 mm, etc.

[0029] In a preferred embodiment, the moisture permeability of the barrier substrate layer at 30°C and 90%RH is preferably 3-90 g·(m³). 2 ·24h) -1 More preferably 5-80g·(m 2 ·24h) -1 It can also be specifically 6g·(m 2 ·24h) -1 7g·(m 2 ·24h) -1 10g·(m 2 ·24h) -1 15g·(m 2 ·24h) -1 20g·(m 2 ·24h) -1 25g·(m 2 ·24h) -1 30g·(m 2 ·24h) -1 35g·(m 2 ·24h) -1 40g·(m 2 ·24h) -1 45g·(m 2 ·24h) -1 50g·(m 2 ·24h) -1 55g·(m 2 ·24h) -1 60g·(m 2 ·24h) -1 65g·(m 2·24h) -1 70g·(m 2 ·24h) -1 75g·(m 2 ·24h) -1 wait.

[0030] In a preferred embodiment, the barrier substrate layer is made of polyethylene terephthalate, with a moisture permeability of 15-50 m³ / h at 30°C and 90% RH. 2 ·24h) -1 .

[0031] In a preferred embodiment, the barrier substrate layer is made of polypropylene, with a moisture permeability of 3-25 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 The polypropylene may specifically be oriented polypropylene.

[0032] In a preferred embodiment, the thickness of the heat-sealing layer is 0.02-0.05 mm, specifically 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, and 0.045 mm, etc.

[0033] In the parallel direction of the packaging material, due to the material and specific specifications and parameters of the intermediate layer, it has a loose and porous structure. When the desiccant is heated, the moisture absorbed by the desiccant begins to evaporate into water vapor and escapes from the absorbent. At the same time, the gas (oxygen, nitrogen, carbon dioxide) inside the desiccant expands in volume as the temperature rises. At this time, the expanded water vapor and gas diffuse from the pores of the heat-sealing layer to the intermediate layer, and finally escape from the side of the packaging material, thus preventing the desiccant from over-expanding and bulging. This allows the desiccant to be used in specific scenarios such as video surveillance lenses and automotive headlights. To achieve this purpose, the thickness of the intermediate layer must be at least 0.035mm. If the thickness is lower than this, the water vapor diffusion rate of the intermediate layer will not meet the requirements, and the desiccant will bulge. In severe cases, this can cause the displacement of other devices in the confined space, affecting the normal use of camera equipment, such as video surveillance or automotive headlights. The thickness of the intermediate layer should be less than 0.23mm to avoid the intermediate layer being too thick and affecting other properties of the packaging material. In a preferred embodiment, the thickness of the intermediate layer is 0.056-0.160 mm, and this thickness can also be specifically 0.060 mm, 0.065 mm, 0.070 mm, 0.075 mm, 0.080 mm, 0.085 mm, 0.090 mm, 0.095 mm, 0.100 mm, 0.110 mm, 0.120 mm, 0.130 mm, 0.140 mm, and 0.150 mm, etc. The material of the intermediate layer can be anything that meets the requirements, and is preferably non-woven fabric or paper.

[0034] In a preferred embodiment, the basis weight of the intermediate layer is crucial for water vapor diffusion. Excessive basis weight leads to excessively high density in the intermediate layer, failing to meet the water vapor diffusion requirements and also affecting the material's light transmittance, thus failing to meet usage requirements. Conversely, insufficient basis weight results in poor mechanical properties of the intermediate layer. To achieve the above effects, the basis weight of the intermediate layer is preferably 16.0-55.0 g / m³. 2 More preferably, it is 18.0-50.0 g / m 2 It can also be specifically stated as 19.0 g / m 2 20.0g / m 2 21.0g / m 2 22.0g / m 2 25.0g / m 2 27.0g / m 2 30.0g / m 2 32.0g / m 2 35.0g / m 2 38.0g / m 2 40.0g / m 2 42.0g / m 2 45.0g / m 2 48.0g / m 2 etc.; the preferred air permeability of the intermediate layer is 60~6000 L / m. 2 s; more preferably 80~5800 L / m 2 s can also be specifically defined as 90 L / m 2 s, 100L / m 2 s, 110L / m 2 s, 120L / m 2 s, 150L / m 2 s, 170L / m 2 s, 200L / m 2 s, 250L / m 2 s, 300L / m 2 s, 350L / m 2 s, 400L / m 2 s, 450L / m 2 s, 500L / m 2 s, 550L / m 2 s, 600L / m 2 s, 650L / m 2 s, 700L / m 2 s, 750L / m 2 s, 800L / m 2 s, 1000L / m 2 s, 1500L / m2 s, 2000L / m 2 s, 2500L / m 2 s, 3000L / m2s, 3500L / m 2 s, 4000L / m 2 s, 4500L / m 2 s, 5000L / m 2 s, 5500L / m 2 s etc. When the air permeability is less than 55L / m 2 When the lateral moisture diffusion rate of the intermediate layer is too low, the moisture diffusion requirements will not be met, and the drying bag will bulge, which in severe cases will affect the use of the equipment; the air permeability should also not be too high, for example, exceeding 6500 L / m³. 2 The weight, thickness, and air permeability of the intermediate layer will affect its performance, such as tensile strength and tear strength. Furthermore, an intermediate layer that meets the above requirements for basis weight, thickness, and air permeability can provide sufficient support, tensile strength, and tear resistance to the desiccant packaging material, thereby improving its mechanical properties.

[0035] In a preferred embodiment, the transmittance at a wavelength of 380-780nm is 0.8-45%, preferably 5-40%, and can specifically be 5%, 7%, 9%, 10%, 12%, 14%, 16%, 18%, 23%, 28%, 33%, 38%, 40%, etc. This invention, by controlling the material, thickness, and corresponding specifications and parameters of each layer, ensures that the desiccant packaging material exhibits a certain degree of transparency and visibility, allowing direct visual observation of whether the desiccant inside the bag needs to be replaced after the desiccant bag is made.

[0036] In this invention, the desiccant packaging material is prepared by a conventional adhesive bonding method. Typically, without limitation, the adhesive includes T-1070, and the various film layers are bonded together with adhesive. The perforation method of the heat-sealing layer is also a conventional perforation method in the art.

[0037] In summary, the specific barrier substrate layer, intermediate layer, and heat-sealing layer in this invention work synergistically to provide excellent barrier properties, preventing desiccant leakage. The specific materials and thicknesses ensure a certain degree of transparency in the desiccant packaging material, allowing for direct visual inspection of the desiccant's need for replacement after the desiccant bag is manufactured. Since water vapor and gases (oxygen, nitrogen, carbon dioxide) inside the desiccant bag expand in volume with increasing temperature, the types and thicknesses of the barrier substrate layer and intermediate layer are determined first to ensure excellent transparency and barrier properties in the vertical direction of the packaging material. The properties of the barrier substrate layer and intermediate layer themselves essentially limit the permeability of water vapor and gases. Within a relatively large range, the specific porosity of the heat-sealing layer and the specific average pore size of the through-holes can further adjust the overall water vapor and gas permeability of the packaging material, limiting it to a smaller range so that the packaging material has appropriate water vapor and gas permeability in the vertical direction; while in the parallel direction of the packaging material, because the specific material of the intermediate layer has a loose and porous structure, gas and water vapor can escape from the side of the intermediate layer, avoiding excessive expansion and bulging of the desiccant bag, making the desiccant bag suitable for specific scenarios such as video surveillance cameras and automotive headlights; in addition, the intermediate layer can also provide support for the desiccant packaging material, improving the mechanical properties of the desiccant packaging material. Example

[0038] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0039] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0040] In this invention, the thickness of each layer was measured using a micrometer; the moisture permeability was measured using a Langguang C360H water vapor transmission meter at 30°C and 90% RH, specifically by selecting membrane samples at six different locations and measuring their moisture permeability using the meter; porosity was measured using an area comparison method, with a selected area of ​​1m². 2 The pore area of ​​the membrane was measured using an MG10085-1A100X reading microscope, and the porosity was calculated using the formula: pore area / 1m². 2×100%, the aperture size was tested using an MG10085-1A100X reading microscope, and the average value was taken after 3 tests. The visible light transmittance of the film material was tested using a Linshang LS101 solar film tester. The barrier performance was tested using an MP-3000A1 vibration tester. The air permeability was measured using GB / T5453 "Determination of air permeability of textile fabrics".

[0041] The manufacturer of the nonwoven fabric is Hangzhou Jinbaihe Nonwoven Fabric.

[0042] The manufacturer of polyethylene-1 is Wenzhou Huaxia Plastics Industry Co., Ltd., with a weight-average molecular weight of 5-25 Mw.

[0043] The manufacturer of polyethylene-2 ​​is Wenzhou Huaxia Plastics Industry, with a weight-average molecular weight of 10-30 Mw;

[0044] The manufacturer of polyethylene-3 is Wenzhou Huaxia Plastics Industry, with a weight-average molecular weight of 25-50 Mw;

[0045] The manufacturer of the polyethylene terephthalate film is Anhui Guofeng New Materials, and the brand name is BOPET12 flat film.

[0046] The manufacturer of the cast polypropylene is Anhui Jintian New Materials, and the grade is CPP25 low-temperature composite film.

[0047] Example 1

[0048] This embodiment provides a desiccant packaging material, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes the following settings in sequence:

[0049] The polypropylene barrier substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 18.79 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0050] The second intermediate layer is made of non-woven fabric, with a thickness of 0.062 mm and a basis weight of 30 g / m². 2 The air permeability is 647 L / m². 2 s;

[0051] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0052] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 14.73 g·(m³). 2 ·24h) -1 .

[0053] Example 2

[0054] This embodiment provides a desiccant packaging material, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes the following settings in sequence:

[0055] The polyethylene terephthalate barrier substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0056] The second intermediate layer is made of non-woven fabric, with a thickness of 0.117 mm and a basis weight of 28 g / m². 2 The air permeability is 1233L / m². 2 s;

[0057] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0058] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 33.62 g·(m³). 2 ·24h) -1 .

[0059] Example 3

[0060] This embodiment provides a desiccant packaging material, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes the following settings in sequence:

[0061] The polyethylene terephthalate barrier substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0062] The second intermediate layer is made of non-woven fabric, with a thickness of 0.117 mm and a basis weight of 28 g / m². 2 The air permeability is 1233L / m². 2 s;

[0063] The heat-sealing layer 3 is made of cast polypropylene with a porosity of 0.019%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0064] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 10.18 g (m³). 2 ·24h) -1 .

[0065] Example 4

[0066] This embodiment provides a desiccant packaging material, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes the following settings in sequence:

[0067] The polyethylene terephthalate barrier substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0068] The second intermediate layer is made of non-woven fabric, with a thickness of 0.062 mm and a basis weight of 30 g / m². 2 The air permeability is 647 L / m². 2 s;

[0069] The heat-sealing layer 3 is made of polyethylene-2 ​​with a porosity of 1.57%, an average pore size of 0.3 mm, and a thickness of 0.025 mm.

[0070] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 27.21 g·(m³). 2 ·24h) -1 .

[0071] Comparative Example 1

[0072] This comparative example provides a desiccant packaging material, the structural schematic diagram of which is shown below. Figure 2 As shown, it includes the following settings in sequence:

[0073] The second intermediate layer is made of non-woven fabric, with a thickness of 0.062 mm and a basis weight of 30 g / m². 2 The air permeability is 647 L / m². 2 s;

[0074] The polyethylene terephthalate barrier substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0075] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0076] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 11.3 g·(m³). 2 ·24h) -1 .

[0077] Comparative Example 2

[0078] This comparative example provides a desiccant packaging material, comprising, in sequence:

[0079] The polyethylene terephthalate substrate layer 1, with a thickness of 0.012 mm, has a vertical moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0080] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0081] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 17.32 m³ / s. 2 ·24h) -1 .

[0082] Comparative Example 3

[0083] This comparative example provides a desiccant packaging material, comprising, in sequence:

[0084] The polyethylene terephthalate substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0085] Heat-sealing layer 3 is made of polyethylene-3 and has a thickness of 0.060 mm;

[0086] Polyethylene terephthalate substrate layer 1 and heat-sealing layer 3 are heat-sealed to obtain desiccant packaging material. The desiccant packaging material is then subjected to needle-punch perforation treatment to create through holes with a porosity of 0.09%.

[0087] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 34.65 g·(m³). 2 ·24h) -1 .

[0088] Comparative Example 4

[0089] This comparative example provides a desiccant packaging material, which includes the following components arranged sequentially:

[0090] The polyamide barrier substrate layer 1, with a thickness of 0.015 mm, has a moisture permeability of 627 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0091] Intermediate layer 2 is made of polyethylene terephthalate, with a thickness of 0.012 mm and a moisture permeability of 41.76 g·(m³). 2 ·24h) -1 ;

[0092] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0093] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 10.70 g·(m³). 2 ·24h) -1 .

[0094] Comparative Example 5

[0095] This comparative example provides a desiccant packaging material, which includes the following components arranged sequentially:

[0096] The polyethylene terephthalate substrate layer 1, with a thickness of 0.012 mm, has a moisture permeability of 41.76 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0097] The second intermediate layer is made of a polyethylene breathable membrane with a thickness of 0.032 mm.

[0098] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 0.251%, an average pore size of 0.2 mm, and a thickness of 0.025 mm.

[0099] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 26.93 g·(m³). 2 ·24h) -1 .

[0100] Comparative Example 6

[0101] This comparative example provides a desiccant packaging material, comprising, in sequence:

[0102] The polyamide barrier substrate layer 1, with a thickness of 0.015 mm, has a moisture permeability of 627 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ;

[0103] The second intermediate layer is made of non-woven fabric with a thickness of 0.029 mm and a basis weight of 58 g / m². 2 The air permeability is 48.5 L / m. 2 s;

[0104] The heat-sealing layer 3 is made of polyethylene-1 with a porosity of 12.56%, an average pore size of 0.4 mm, and a thickness of 0.025 mm.

[0105] At 30℃ and 90%RH, the moisture permeability of the desiccant packaging material is 415.65 g·(m³). 2 ·24h) -1 .

[0106] Test case

[0107] The barrier properties of desiccant packaging materials were tested using an MP-3000A1 vibration testing machine.

[0108] The transmittance of desiccant packaging materials was tested using the Linshang LS101 solar film tester. The light source was selected as visible light with a wavelength of 380-780nm, and the transmittance was directly read to characterize the transparency.

[0109] The service life test method involves observing whether fogging occurs on the glass surface during alternating high and low temperatures. Specifically, the equipment environment is first heated by 20°C for 1 hour, kept at that temperature for 2 hours, and then cooled by 20°C for 1 hour. The glass surface is then observed for fogging. If fogging occurs, the service life period is considered to have been reached.

[0110] The desiccant packaging materials of the examples and comparative examples were filled with desiccant to make desiccant bags. The specific preparation method was as follows: the desiccant packaging materials of the examples and comparative examples were heat-sealed to obtain desiccant bags. 15g of magnesium chloride desiccant (purchased from Hangzhou Jiashuang Packaging Materials Co., Ltd., brand name: magnesium chloride desiccant) was filled into the desiccant bags. The desiccant bags were placed in an environment of 30℃ and 90%RH. The desiccant absorbed moisture and increased in weight, reaching 160% of its initial weight. The desiccant bags were then placed in an oven at 105℃ for 1 hour, and their appearance was observed and recorded as the shape. State 1; then take out the desiccant bag and place it in a 25℃, 50%RH environment for 24 hours, and then observe its appearance and record it as State 2; compare State 1 and State 2 with the naked eye to determine whether there is bulging, which characterizes the expansion performance of the desiccant packaging material. The number of "★" corresponds to the degree of expansion and bulging. V% represents the volume increase, and then classify the levels as follows: 5 < V ≤ 20, recorded as "★", 20 < V ≤ 40, recorded as "★★", 40 < V ≤ 60, recorded as "★★★", 60 < V ≤ 80, recorded as "★★★★", 80 < V, recorded as "★★★★★".

[0111] The test results are shown in Table 1.

[0112] Table 1

[0113]

[0114] The table shows that the embodiments can balance transparency, dustproof barrier, service life and low expansion.

[0115] Example 2 uses the same barrier substrate material as Comparative Example 1. A comparison shows that although Comparative Example 1 has good transparency, it has obvious bulging, which can cause other devices to shift in a small, enclosed space, making it unsuitable for practical application. This demonstrates that the specific lamination method of the present invention can ensure transparency, dustproof barrier, and low expansion.

[0116] A comparison of Example 2 and Comparative Example 2 shows that although the transparency increases significantly after removing the intermediate layer, the expanding gas cannot be directly discharged, the degree of bulging increases, and it cannot be put into practical use.

[0117] Comparing Example 2 with Comparative Example 3, it can be seen that although the structures are similar, the moisture permeation mechanisms are different. Comparative Example 3 is prone to powder leakage and cannot meet the high requirements for use.

[0118] Comparing Examples 1 and 2 with Comparative Examples 4 and 5, it can be seen that the specific material of the intermediate layer has a loose and porous structure, allowing water vapor and gas to escape from the side of the intermediate layer, which can ensure low expansion of the packaging material and long-term usability.

[0119] Comparative Example 6 has a lower thickness and higher weight, resulting in insufficient air permeability. This leads to a slower rate of gas expulsion and increased bulging, making it unsuitable for practical use. Furthermore, its overall moisture permeability is too high, resulting in a shorter service life and making it unsuitable for use in special fields such as camera equipment or vehicle lights.

[0120] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A desiccant packaging material, characterized in that, The desiccant packaging material comprises a barrier substrate layer, an intermediate layer, and a heat-sealing layer stacked together; the stacking is arranged sequentially. The thickness of the barrier substrate layer is 0.010-0.032 mm; The barrier substrate layer has a moisture permeability of 2-100 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 ; The thickness of the intermediate layer is 0.035-0.23 mm, and the basis weight is 8.0-56.0 g / m³. 2 Air permeability is 55~6500L / m 2 s; The thickness of the heat-sealing layer is 0.01-0.06 mm; The heat-sealing layer is made of at least one of polyethylene and polypropylene. The heat-sealing layer has through holes, the porosity of the heat-sealing layer is 0.01-30%, and the average pore size of the through holes is 0.05-0.75 mm.

2. The desiccant packaging material according to claim 1, characterized in that, The desiccant packaging material is used in camera equipment or vehicle lights. The moisture permeability of the desiccant packaging material at 30°C and 90% RH is 2.0-80.0 g·(m³). 2 ·24h) -1 .

3. The desiccant packaging material according to claim 1, characterized in that, The porosity of the heat-sealing layer is 0.5-18%, and the average pore size of the through hole is 0.1-0.5 mm.

4. The desiccant packaging material according to claim 1, characterized in that, The thickness of the barrier substrate layer is 0.012-0.025 mm.

5. The desiccant packaging material according to claim 1, characterized in that, The barrier substrate layer is made of polyethylene terephthalate, with a moisture permeability of 15-50 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 .

6. The desiccant packaging material according to claim 1, characterized in that, The barrier substrate layer is made of polypropylene, with a moisture permeability of 3-25 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 .

7. The desiccant packaging material according to claim 1, characterized in that, The thickness of the heat-sealing layer is 0.020-0.05 mm.

8. The desiccant packaging material according to claim 1, characterized in that, The thickness of the intermediate layer is 0.056-0.160 mm, and the basis weight is 16.0-55.0 g / m³. 2 Air permeability is 60~6000L / m 2 s.

9. The desiccant packaging material according to claim 2, characterized in that, The desiccant packaging material has a moisture permeability of 10-50 g·(m³) at 30°C and 90% RH. 2 ·24h) -1 .

10. The desiccant packaging material according to claim 1, characterized in that, At wavelengths of 380-780nm, the transmittance is 0.8-45%.

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