Preparation method of composite humidifying tablet and composite humidifying tablet

Abstract

The invention discloses a preparation method of a composite humidifying sheet and the composite humidifying sheet. The preparation method comprises the following steps: mixing polyol, metal salt and a solvent to obtain a water absorption solution; immersing polyester cotton into the water absorption solution, taking out, draining and drying after the polyester cotton is completely immersed in the water absorption solution, and cutting the obtained polyester water absorption cotton to obtain a lower water absorption layer and an upper water absorption layer; raw rubber is placed on an open mill to be mixed and packaged for a period of time, water-absorbent resin and polyhydric alcohol are added for continuous mixing for a period of time, a vulcanizing agent is added for continuous mixing for a period of time, the mixture is pressed into sheets after mixing and placed for a period of time to complete vulcanization, and obtained water-absorbent rubber is cut to obtain a rubber humidifying layer; the packaging layer, the lower water absorption layer, the rubber humidifying layer, the upper water absorption layer and the semi-permeable membrane layer are sequentially placed from bottom to top, the edges of the packaging layer and the semi-permeable membrane layer are bonded, and the composite humidifying sheet is obtained. The composite humidity adjusting sheet has a bidirectional humidity adjusting function, is high in water absorption rate and large in moisture absorption amount, and does not generate flowing water.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of humidity control, and particularly relates to a preparation method of a composite humidity control sheet and the composite humidity control sheet. BACKGROUND

[0002] Electronic devices, precision instruments, battery packs of new energy vehicles, and power equipment (such as power cabinets, 5G base stations, etc.) are highly sensitive to the humidity of the operating environment, and are prone to failure due to humidity imbalance in a closed environment. Specifically, too high humidity can cause electrical insulation performance to decrease, metals to rust, and circuits to age, and can even cause short circuits; and too low humidity is prone to static electricity, which can damage electronic components.

[0003] Taking a power cabinet as an example, the humidity thereof needs to be strictly controlled within the range of 40% RH to 60% RH. Traditional desiccants only have a one-way moisture absorption function and cannot cope with humidity fluctuations. When the environmental humidity decreases, the absorbed water cannot be released, resulting in failure of the desiccant material and causing the environmental humidity to be too low. In addition, the desiccant needs to be replaced regularly, and the maintenance cost is high.

[0004] In addition, the commonly used humidity adjusting products also include a condensing dehumidifier. The condensing dehumidifier has a certain dehumidification capacity, but it has poor adaptability in a low-temperature environment, and has a large volume itself, which is difficult to adapt to small spaces or compact environments (such as power cabinets, battery packs, etc.). SUMMARY

[0005] In view of the defects of the prior art, the application provides a preparation method of a composite humidity control sheet and the composite humidity control sheet. The prepared composite humidity control sheet has a two-way humidity control function, a fast water absorption rate, a large moisture absorption amount, and does not produce flowing water.

[0006] The technical solution adopted by the application to solve the technical problems is as follows:

[0007] A preparation method of a composite humidity control sheet, comprising the following steps:

[0008] S1, configuring a water absorption solution: mixing a polyol, a metal salt, and a solvent, stirring until the metal salt is completely dissolved, and then standing for a period of time to obtain a water absorption solution;

[0009] S2, preparing a water absorption layer: selecting a sheet-shaped polyester cotton, immersing the polyester cotton in the water absorption solution in step S1, taking out and naturally draining after the water absorption solution completely soaks the polyester cotton, and then drying to obtain polyester water absorption cotton, cutting the polyester water absorption cotton into a required size to obtain a water absorption layer;

[0010] S3, preparing the rubber humidifying layer: after the temperature of the open mill is raised to a certain temperature, raw rubber is first placed on the open mill to mix and pack for a period of time, then water-absorbing resin and polyhydric alcohol are added to continue mixing for a period of time, then vulcanizing agent is added to continue mixing for a period of time, after the mixing is completed, the obtained rubber mixture is pressed into a sheet and placed for a period of time to complete vulcanization, to obtain water-absorbing rubber, and the water-absorbing rubber is cut into a desired size to obtain the rubber humidifying layer;

[0011] S4, packaging of the composite humidifying sheet: two pieces of the water-absorbing layer are selected and respectively referred to as the lower water-absorbing layer and the upper water-absorbing layer, and a sheet-shaped packaging layer and a semi-permeable membrane layer are selected, the packaging layer, the lower water-absorbing layer, the rubber humidifying layer, the upper water-absorbing layer and the semi-permeable membrane layer are sequentially placed from bottom to top, then the edges of the packaging layer and the semi-permeable membrane layer are bonded together, to realize packaging of the lower water-absorbing layer, the rubber humidifying layer and the upper water-absorbing layer, to obtain the composite humidifying sheet.

[0012] Further, in step S4: the rubber humidifying layer is multiple pieces, and the multiple pieces of the rubber humidifying layer are between the lower water-absorbing layer and the upper water-absorbing layer.

[0013] Further, in step S1: the weight parts of the polyhydric alcohol is 20-50 parts, the weight parts of the metal salt is 2-5 parts, and the weight parts of the solvent is 5-10 parts; the polyhydric alcohol is selected from one of ethylene glycol, glycerol, butanetetrol and xylitol, the metal salt is selected from one of calcium chloride, sodium formate and sodium acetate, and the solvent is deionized water.

[0014] Further, in step S2: the polyester cotton is composed of polyester fiber and water-absorbing fiber, the polyester fiber is selected from one of polyethylene terephthalate PET and polybutylene terephthalate PBT, and the water-absorbing fiber is selected from one of wood pulp, cellulose fiber, wood fiber and viscose fiber.

[0015] Further, in step S3: the weight parts of the raw rubber is 40-80 parts, the weight parts of the water-absorbing resin is 10-30 parts, the weight parts of the polyhydric alcohol is 2-5 parts, and the weight parts of the vulcanizing agent is 0.1-0.8 parts; the raw rubber is selected from one of nitrile rubber, silicone rubber and acrylate rubber, the water-absorbing resin is selected from one of starch-based water-absorbing resin, cellulose-based water-absorbing resin and synthetic resin polyacrylate-based water-absorbing resin, the polyhydric alcohol is selected from one of ethylene glycol, glycerol, butanetetrol and xylitol, and the vulcanizing agent is selected from one of thiuram disulfide and peroxide.

[0016] Further, in step S3: 0.1-0.8 parts by weight of vulcanizing aid is also added at the same time as the vulcanizing agent; the vulcanizing aid is selected from one of sodium stearate, tetramethylthiuram disulfide and benzothiazole disulfide.

[0017] Further, in step S4: the packaging layer is selected from one of polyethylene terephthalate PET film, polyimide PI film, polyurethane PU film, ethylene-tetrafluoroethylene copolymer ETFE film, the semi-permeable membrane layer is selected from one of polytetrafluoroethylene semi-permeable membrane, polytetrafluoroethylene polyethylene terephthalate composite semi-permeable membrane, polyethylene polypropylene composite semi-permeable membrane.

[0018] Further,

[0019] In step S2: the thickness of the water absorption layer is 0.5-1mm;

[0020] In step S3: the thickness of the rubber humidity regulating layer is 0.5-2mm;

[0021] In step S4: the thickness of the packaging layer is 0.1-0.5mm, the thickness of the semi-permeable membrane layer is 0.1-0.5mm; the area of the packaging layer is equal to that of the semi-permeable membrane layer, the area of the upper water absorption layer, the rubber humidity regulating layer and the lower water absorption layer is equal, and the area of the packaging layer is greater than that of the rubber humidity regulating layer; the edges of the packaging layer and the semi-permeable membrane layer are bonded together by hot pressing or ultrasonic welding.

[0022] Further,

[0023] In step S1: the standing time is 2-4h;

[0024] In step S2: the drying treatment temperature is 95-105℃ and the time is 4-8h;

[0025] Step S3 specifically is: after the open mill is heated to 65-75℃, the raw rubber is first placed on the open mill for mixing and packaging for 5-15min, then the water absorption resin and polyol are added for further mixing for 5-15min, and then the vulcanizing agent is added for further mixing for 5-15min, after the mixing is completed, the obtained rubber mixture is pressed into a sheet and placed for 18-30h to complete vulcanization, obtaining the water absorption rubber, the water absorption rubber is cut into the required size to obtain the rubber humidity regulating layer.

[0026] A composite humidity regulating sheet is prepared by the preparation method of the composite humidity regulating sheet, comprising a packaging layer, a lower water absorption layer, a rubber humidity regulating layer, an upper water absorption layer and a semi-permeable membrane layer arranged from bottom to top, and the edges of the packaging layer and the semi-permeable membrane layer are bonded together to package the lower water absorption layer, the rubber humidity regulating layer and the upper water absorption layer between the semi-permeable membrane layer and the packaging layer.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] In this invention, the composite moisture-regulating sheet has a lower absorbent layer arranged below the rubber moisture-regulating layer and an upper absorbent layer arranged above the rubber moisture-regulating layer. Both the upper and lower absorbent layers are self-made polyester absorbent cotton, which is made by impregnating polyester cotton with an absorbent solution and then drying it. The absorbent solution is made by mixing polyol, metal salt, and solvent. The polyol in the absorbent solution increases the hydrophilicity and water-locking ability of the polyester absorbent cotton, and the metal salt in the absorbent solution has hygroscopic properties, thus giving the polyester absorbent cotton its hygroscopic properties. Furthermore, by impregnating the polyester cotton with the absorbent solution... This process increases the osmotic pressure of the resulting polyester absorbent cotton, enabling rapid absorption of moisture from the air. The resulting polyester absorbent cotton thus exhibits high water absorption. The rubber moisture-regulating layer is a self-made absorbent rubber, which is produced by mixing and vulcanizing raw rubber, absorbent resin, polyol, and vulcanizing agent. The raw rubber and polyol used in preparing the absorbent rubber increase its hydrophilicity and water-locking ability, while the absorbent resin possesses hydrophilic, water-locking, and water-molecule-capturing capabilities. This combination results in a highly absorbent rubber with excellent water absorption properties. The composite humidity-regulating sheet is characterized by its high moisture absorption capacity. Polyester absorbent cotton has a high water absorption rate, and absorbent rubber also has a high moisture absorption capacity. This results in the upper and lower absorbent layers having both high absorption rates, and the rubber moisture-regulating layer having a high moisture absorption capacity. Consequently, the composite humidity-regulating sheet can absorb several times its own weight in water while maintaining a rapid moisture absorption rate. Furthermore, the upper, lower, and rubber absorbent layers work synergistically to significantly enhance the humidity regulation capability of the composite humidity-regulating sheet. The strong water-locking properties of the rubber moisture-regulating layer also limit the generation of flowing water, achieving maximum absorption capacity. Even under humid conditions, no flowing water will occur, thus reducing the risk of leakage. This invention utilizes the osmotic pressure formed between the composite humidity regulating sheet and the surrounding air to absorb or release moisture from the air. The composite humidity regulating sheet has the function of bidirectional autonomously regulating ambient humidity (absorbing and releasing moisture), which can accurately maintain the humidity stability of the environment in which the equipment is located, effectively prevent the formation of condensation in the environment in which the equipment is located, and ensure the long-term stable operation of the equipment. Moreover, the composite humidity regulating sheet with high efficiency in absorbing and locking water can still maintain stable humidity regulation characteristics under harsh conditions. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the layered structure of the composite humidity-regulating sheet in this invention;

[0030] Figure 2 This is a schematic diagram of the structure of the composite humidity regulating sheet after encapsulation in this invention.

[0031] The following are the labels in the figure: 1. Composite humidity regulating sheet, 101. Encapsulation layer, 10201. Lower absorbent layer, 10202. Upper absorbent layer, 103. Rubber humidity regulating layer, 104. Semi-permeable membrane layer. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] A method for preparing a composite humidity-regulating sheet includes the following steps:

[0036] S1. Preparation of absorbent solution: Mix polyol, metal salt and solvent, stir until the metal salt is completely dissolved, and then let stand for a period of time to obtain absorbent solution;

[0037] S2. Preparation of absorbent layer: Select sheet-like polyester cotton, immerse the polyester cotton in the absorbent solution in step S1, and after the absorbent solution has completely soaked the polyester cotton, take it out and let it drain naturally, and then dry it to obtain polyester absorbent cotton. Cut the polyester absorbent cotton into the required size to obtain the absorbent layer.

[0038] S3. Preparation of rubber moisture-conditioning layer: After the open mill is heated to a certain temperature, the raw rubber is first placed on the open mill for mixing and packaging for a period of time. Then, water-absorbing resin and polyol are added and mixed for a period of time. Then, vulcanizing agent is added and mixed for a period of time. After the mixing is completed, the obtained rubber mixture is pressed into sheets and left for a period of time to complete vulcanization, and water-absorbing rubber is obtained. The water-absorbing rubber is cut into the required size to obtain rubber moisture-conditioning layer 103.

[0039] S4. Encapsulation of the composite humidity-regulating sheet: Select two absorbent layers, referred to as the lower absorbent layer 10201 and the upper absorbent layer 10202, respectively. Select a sheet-like encapsulation layer 101 and a semi-permeable membrane layer 104. First, place the encapsulation layer 101, the lower absorbent layer 10201, the rubber humidity-regulating layer 103, the upper absorbent layer 10202, and the semi-permeable membrane layer 104 sequentially from bottom to top. Then, bond the edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 together to encapsulate the lower absorbent layer 10201, the rubber humidity-regulating layer 103, and the upper absorbent layer 10202, thus obtaining the composite humidity-regulating sheet 1. (See...)Figure 1 and Figure 2 .

[0040] The composite moisture-regulating sheet 1 has a lower absorbent layer 10201 arranged below the rubber moisture-regulating layer 103 and an upper absorbent layer 10202 arranged above the rubber moisture-regulating layer 103. Both the upper absorbent layer 10202 and the lower absorbent layer 10201 are self-made polyester absorbent cotton. The polyester absorbent cotton is made by impregnating polyester cotton with an absorbent solution and then drying it. The absorbent solution is made by mixing polyol, metal salt, and solvent. The polyol in the absorbent solution can increase the hydrophilicity and water-locking ability of the polyester absorbent cotton, and the metal salt in the absorbent solution has hygroscopic properties, which makes the polyester absorbent cotton hygroscopic. Impregnating cotton with absorbent water increases the osmotic pressure of the resulting polyester absorbent cotton, enabling rapid absorption of moisture from the air. This results in a polyester absorbent cotton with a high water absorption rate. The rubber moisture-regulating layer 103 is a self-made absorbent rubber, which is produced by mixing and vulcanizing raw rubber, absorbent resin, polyol, and vulcanizing agent. The raw rubber and polyol used in preparing the absorbent rubber increase its hydrophilicity and water-locking ability, while the absorbent resin possesses hydrophilic, water-locking, and water-molecule-capturing capabilities. This results in a high moisture absorption capacity for the final absorbent rubber. The composite moisture-regulating sheet 1 possesses the characteristics of rapid water absorption, and due to the high moisture absorption capacity of polyester absorbent cotton and rubber absorbent rubber, the upper absorbent layer 10202 and the lower absorbent layer 10201 have rapid water absorption rates, while the rubber moisture-regulating layer 103 has a high moisture absorption capacity. This allows the composite moisture-regulating sheet 1 to absorb several times its own weight in water while maintaining a rapid moisture absorption rate. Furthermore, the synergistic effect of the upper absorbent layer 10202, the rubber moisture-regulating layer 103, and the lower absorbent layer 10201 significantly enhances the humidity regulation capability of the composite moisture-regulating sheet 1. Additionally, the strong water-locking properties of the rubber moisture-regulating layer 103 further contribute to its superior performance. The invention prevents the generation of flowing water, and even under extreme moisture absorption conditions, no flowing water will appear, thereby reducing the risk of leakage. The invention utilizes the osmotic pressure formed between the composite humidity regulating plate 1 and the surrounding air to absorb or release water vapor from the surrounding air. The composite humidity regulating plate 1 has the function of bidirectional autonomously regulating the humidity of the environment by absorbing and releasing moisture, which can accurately maintain the humidity stability of the environment in which the equipment is located, effectively prevent the formation of condensation in the environment in which the equipment is located, so as to ensure the long-term stable operation of the equipment. Moreover, the composite humidity regulating plate 1 with high efficiency in absorbing and locking water can still maintain stable humidity regulation characteristics under harsh conditions.

[0041] The composite humidity control sheet of the present invention can solve the problems caused by the humidity control methods in the background art that mainly rely on traditional desiccants and condensation dehumidifiers.

[0042] The semi-permeable membrane layer 104 serves to provide breathability and waterproofing.

[0043] In one embodiment, in step S4: the rubber moisture-conditioning layer 103 is multiple pieces, and the multiple pieces of rubber moisture-conditioning layer 103 are located between the lower absorbent layer 10201 and the upper absorbent layer 10202.

[0044] In one embodiment, in step S1: the polyol is 20-50 parts by weight, the metal salt is 2-5 parts by weight, and the solvent is 5-10 parts by weight; the polyol is selected from ethylene glycol, glycerol, butanetetrol, and xylitol, the metal salt is selected from calcium chloride, sodium formate, and sodium acetate, and the solvent is deionized water.

[0045] Preferably, in step S1: the polyol is butanetetraol and the metal salt is calcium chloride.

[0046] In one embodiment, in step S2: the polyester cotton is woven and composited from polyester fibers and absorbent fibers. The polyester fibers are selected from polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and the absorbent fibers are selected from wood pulp, cellulose fibers, wood fibers, and viscose fibers. Preferably, in step S2: the polyester fibers are polyethylene terephthalate (PET), and the absorbent fibers are viscose fibers.

[0047] Since polyester cotton is made of polyester fiber and absorbent fiber, and absorbent fiber has the characteristics of being hydrophilic and water-locking, the resulting polyester cotton also has the characteristics of being hydrophilic and water-locking. Polyester absorbent cotton is made by impregnating polyester cotton with absorbent water and then drying it. In this way, through the combination of polyester cotton with polyols and metal salts in the absorbent water, the resulting polyester absorbent cotton has the characteristic of fast water absorption.

[0048] In one implementation,

[0049] In step S3: the raw rubber is 40-80 parts by weight, the water-absorbing resin is 10-30 parts by weight, the polyol is 2-5 parts by weight, and the vulcanizing agent is 0.1-0.8 parts by weight; the raw rubber is selected from one of nitrile rubber, silicone rubber, and acrylate rubber; the water-absorbing resin is selected from one of starch-based water-absorbing resin, cellulose-based water-absorbing resin, and synthetic resin polyacrylate-based water-absorbing resin; the polyol is selected from one of ethylene glycol, glycerol, butanediol, and xylitol; and the vulcanizing agent is selected from one of trithiocyanate and peroxide.

[0050] Preferably, in step S3, 0.1-0.8 parts by weight of a vulcanizing aid are added along with the vulcanizing agent; the vulcanizing aid is selected from one of sodium stearate, tetramethylthiuram disulfide, and benzothiazole disulfide.

[0051] More preferably, in step S3: the raw rubber is acrylate rubber, the water-absorbing resin is synthetic resin polyacrylate water-absorbing resin, the vulcanizing agent is trithiocyanate, and the vulcanizing aid is sodium stearate.

[0052] In one embodiment, in step S4: the encapsulation layer 101 is selected from polyethylene terephthalate (PET) film, polyimide (PI) film, polyurethane (PU) film, and ethylene-tetrafluoroethylene (ETFE) copolymer film; and the semi-permeable membrane layer 104 is selected from polytetrafluoroethylene (PTFE) semi-permeable membrane, polytetrafluoroethylene-polyethylene terephthalate (PTFE) composite semi-permeable membrane, and polyethylene-polypropylene (PEPP) composite semi-permeable membrane.

[0053] Preferably, in step S4: the encapsulation layer 101 is a polyethylene terephthalate (PET) film, and the semi-permeable membrane layer 104 is a polytetrafluoroethylene (PTFE)-polyethylene terephthalate (PET) composite semi-permeable membrane.

[0054] In one implementation,

[0055] In step S2: the thickness of the absorbent layer is 0.5-1mm, preferably 0.8-1mm;

[0056] In step S3: the thickness of the rubber moisture-conditioning layer 103 is 0.5-2mm;

[0057] In step S4: the thickness of the encapsulation layer 101 is 0.1-0.5 mm, preferably 0.2 mm; the thickness of the semi-permeable membrane layer 104 is 0.1-0.5 mm, preferably 0.1-0.3 mm; the areas of the encapsulation layer 101 and the semi-permeable membrane layer 104 are equal; the areas of the upper absorbent layer 10202, the rubber moisture-regulating layer 103, and the lower absorbent layer 10201 are equal, and the area of ​​the encapsulation layer 101 is larger than the area of ​​the rubber moisture-regulating layer 103; the edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 are bonded together by heat pressing or ultrasonic welding.

[0058] In one implementation,

[0059] In step S1: the settling time is 2-4 hours;

[0060] In step S2: the drying temperature is 95-105℃ and the time is 4-8 hours;

[0061] Step S3 is as follows: After the open mill is heated to 65-75℃, the raw rubber is first placed on the open mill for mixing and packaging for 5-15 minutes. Then, water-absorbing resin and polyol are added and mixing is continued for 5-15 minutes. Then, vulcanizing agent is added and mixing is continued for 5-15 minutes. After mixing, the obtained rubber mixture is pressed into sheets and left to stand for 18-30 hours to complete vulcanization, thus obtaining water-absorbing rubber. The water-absorbing rubber is cut into the required size to obtain rubber moisture-conditioning layer 103.

[0062] A composite humidity-regulating sheet is prepared using the above-described method for preparing a composite humidity-regulating sheet. It includes an encapsulation layer 101, a lower absorbent layer 10201, a rubber humidity-regulating layer 103, an upper absorbent layer 10202, and a semi-permeable membrane layer 104 arranged sequentially from bottom to top. The edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 are bonded together to encapsulate the lower absorbent layer 10201, the rubber humidity-regulating layer 103, and the upper absorbent layer 10202 between the semi-permeable membrane layer 104 and the encapsulation layer 101.

[0063] Example 1

[0064] A method for preparing a composite humidity-regulating sheet includes the following steps:

[0065] S1. Preparation of absorbent solution: Weigh 50g of calcium chloride solid and place it in a beaker. Add 100g of deionized water and stir until the calcium chloride dissolves. Continue to add 400g of butanediol and stir for 30 minutes. Then let it stand for 2 hours to obtain the absorbent solution.

[0066] S2. Preparation of absorbent layer: Select sheet-like polyester cotton, immerse the polyester cotton in the absorbent solution in step S1 for 20-30 seconds. After the absorbent solution has completely soaked the polyester cotton, take it out and let it drain naturally. Then put it in an oven and dry it at 100℃ for 6 hours to obtain polyester absorbent cotton. Cut the polyester absorbent cotton into 4cm×8cm size to obtain the absorbent layer.

[0067] S3. Preparation of rubber moisture-conditioning layer: Prepare 600g raw rubber, 200g water-absorbing resin, 40g polyol, 7g vulcanizing agent and 7g vulcanizing auxiliaries. After the open mill is heated to 70℃, first put the raw rubber on the open mill to mix and pack for 5 minutes, then add water-absorbing resin and polyol and continue to mix for 10 minutes, then add vulcanizing agent and vulcanizing auxiliaries and continue to mix for 10 minutes. After the mixing is completed, press the obtained rubber mixture into a sheet with a thickness controlled at 1-2mm, and let it stand for 24 hours to complete the vulcanization to obtain water-absorbing rubber. Cut the water-absorbing rubber into a size of 4cm×8cm to obtain rubber moisture-conditioning layer 103.

[0068] S4. Encapsulation of the composite humidity-regulating sheet: Select two absorbent layers, designated as the lower absorbent layer 10201 and the upper absorbent layer 10202, respectively. Cut a 6cm × 10cm polyethylene terephthalate (PET) film as the encapsulation layer 101, and cut a 6cm × 10cm polytetrafluoroethylene (PTFE) / polyethylene terephthalate (PET) composite semi-permeable membrane as the semi-permeable membrane layer 104. First, place the encapsulation layer 101, the lower absorbent layer 10201, the rubber humidity-regulating layer 103, the upper absorbent layer 10202, and the semi-permeable membrane layer 104 sequentially from bottom to top. Then, heat-press the edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 together to achieve encapsulation of the lower absorbent layer 10201, the rubber humidity-regulating layer 103, and the upper absorbent layer 10202, resulting in the composite humidity-regulating sheet 1. (See...) Figure 1 and Figure 2 .

[0069] Example 2

[0070] The difference between Example 2 and Example 1 is that the composite humidity-regulating sheet 1 obtained in Example 2 includes two rubber humidity-regulating layers 103, and the two rubber humidity-regulating layers 103 are adjacent to each other and located between the lower absorbent layer 10201 and the upper absorbent layer 10202.

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that the humidity-regulating sheet obtained in Comparative Example 1 has only one absorbent layer, and the absorbent layer is located between the rubber humidity-regulating layer 103 and the semi-permeable membrane layer 104.

[0073] Comparative Example 2

[0074] A method for preparing a humidifying tablet includes the following steps:

[0075] S1. Select sheet-like polyester cotton and cut it into two polyester cotton layers, each measuring 4cm × 8cm, and refer to them as the lower polyester cotton layer and the upper polyester cotton layer, respectively.

[0076] S2. Cut a 6cm×10cm polyethylene terephthalate (PET) film as the encapsulation layer 101, and cut a 6cm×10cm polytetrafluoroethylene (PTFE)-polyethylene terephthalate (PET) composite semi-permeable membrane as the semi-permeable membrane layer 104. First, place the encapsulation layer 101, the lower polyester cotton layer, the upper polyester cotton layer, and the semi-permeable membrane layer 104 in sequence from bottom to top. Then, heat-press the edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 together to achieve encapsulation of the lower polyester cotton layer and the upper polyester cotton layer, thus obtaining the humidity regulating sheet.

[0077] In Comparative Example 2, the polyester cotton layer has the same thickness as the absorbent layer in Example 1; the encapsulation layer 101 in Comparative Example 2 has the same thickness as the encapsulation layer 101 in Example 1; and the semi-permeable membrane layer 104 in Comparative Example 2 has the same thickness as the semi-permeable membrane layer 104 in Example 1.

[0078] Comparative Example 3

[0079] The difference between Comparative Example 3 and Example 1 is that the humidity conditioning sheet obtained in Comparative Example 3 does not include the rubber humidity conditioning layer 103.

[0080] Comparative Example 4

[0081] A method for preparing a humidifying tablet includes the following steps:

[0082] S1. Prepare 600g raw rubber, 200g water-absorbing resin, 40g polyol, 7g vulcanizing agent and 7g vulcanizing auxiliaries. After the open mill is heated to 70℃, first put the raw rubber on the open mill to mix and pack for 5 minutes. Then add the water-absorbing resin and polyol and continue to mix for 10 minutes. Then add the vulcanizing agent and vulcanizing auxiliaries and continue to mix for 10 minutes. After the mixing is completed, press the obtained rubber mixture into a sheet with a thickness controlled at 1-2mm and let it stand for 24 hours to complete the vulcanization to obtain water-absorbing rubber. Cut the water-absorbing rubber into a size of 4cm×8cm to obtain rubber moisture-conditioning layer 103.

[0083] S4. Cut a 6cm×10cm polyethylene terephthalate (PET) film as the encapsulation layer 101, and cut a 6cm×10cm polytetrafluoroethylene (PTFE)-polyethylene terephthalate (PET) composite semi-permeable membrane as the semi-permeable membrane layer 104. Select sheet-shaped polyester cotton and cut it into two polyester cotton layers, each 4cm×8cm in size, which are respectively called the lower polyester cotton layer and the upper polyester cotton layer. First, place the encapsulation layer 101, the lower polyester cotton layer, the rubber humidity-regulating layer 103, the upper polyester cotton layer, and the semi-permeable membrane layer 104 in sequence from bottom to top. Then, heat-press the edges of the encapsulation layer 101 and the semi-permeable membrane layer 104 together to achieve the encapsulation of the lower polyester cotton layer, the rubber humidity-regulating layer 103, and the upper polyester cotton layer, thus obtaining a humidity-regulating sheet.

[0084] The difference between Comparative Example 4 and Example 1 is that: in Comparative Example 4, a lower polyester cotton layer is used to replace the lower absorbent layer 10201 in Example 1, and an upper polyester cotton layer is used to replace the upper absorbent layer 10202 in Example 1. Furthermore, the thickness of the lower polyester cotton layer in Comparative Example 4 is the same as that of the lower absorbent layer 10201 in Example 1, and the thickness of the upper polyester cotton layer in Comparative Example 4 is the same as that of the upper absorbent layer 10202 in Example 1.

[0085] The composite humidity regulating sheet 1 obtained in Examples 1 and 2, as well as the conditioning sheets obtained in each comparative example, were tested, and the test results are shown in Table 1.

[0086] Table 1

[0087]

[0088] In Table 1, the number of "√" marks in a box indicates the number of layers. For example, if two "√" marks are displayed for the absorbent layer in Example 1, it means that the composite humidity control sheet 1 obtained in Example 1 includes two absorbent layers. In Table 1, the moisture absorption capacity is the percentage obtained by dividing the maximum moisture absorption capacity of the humidity control sheet at 45°C and 95%RH by the initial weight when drying. The moisture release capacity is the percentage obtained by dividing the amount of water released by the humidity control sheet per unit time at 25°C and 40%RH by the initial weight when drying. The moisture absorption rate is the time taken to absorb 50% moisture. The water flow condition indicates whether water flow occurs inside the humidity control sheet when it is fully absorbed.

[0089] As can be seen from Table 1:

[0090] Compared with Example 2, Example 1 has one less rubber moisture-conditioning layer 103 than Example 2. Therefore, the moisture absorption and release of Example 1 are smaller than the corresponding parameters of Example 2. This indicates that the number of rubber moisture-conditioning layers 103 has a greater impact on the moisture absorption and release of the moisture-conditioning sheet. In addition, the moisture absorption rate values ​​of Example 1 and Example 2 are very similar, indicating that the number of rubber moisture-conditioning layers 103 has a smaller impact on the water absorption rate of the moisture-conditioning sheet.

[0091] Compared with Comparative Example 1, Example 1 has one more water-absorbing layer than Comparative Example 1. Therefore, the moisture absorption and release of Example 1 are greater than the corresponding parameters of Comparative Example 1. In addition, the moisture absorption rate of Example 1 is smaller than that of Comparative Example 1. Thus, the water absorption rate of Example 1 is faster than that of Comparative Example 1. This shows that the number of water-absorbing layers has a significant impact on the moisture absorption, release, and water absorption rate of the humidity regulating sheet.

[0092] Compared with Comparative Example 3, Example 1 has a larger moisture absorption and release capacity than Comparative Example 3 because the humidity-regulating sheet obtained in Comparative Example 3 does not include the rubber humidity-regulating layer 103. In addition, the moisture absorption rate of Example 1 is smaller than that of Comparative Example 3, indicating that the water absorption rate of Example 1 is faster than that of Comparative Example 3. This shows that without the rubber humidity-regulating layer 103, the moisture absorption, release capacity, and water absorption rate of the humidity-regulating sheet will all be affected. Furthermore, since Comparative Example 3 includes two water-absorbing layers, its moisture absorption capacity is relatively large. However, since Comparative Example 3 does not include the rubber humidity-regulating layer 103, water flow occurs inside even when the sheet is fully saturated with water. This also shows that the rubber humidity-regulating layer 103 can prevent the generation of water flow.

[0093] Compared with Comparative Example 4, Example 1 uses a lower polyester cotton layer to replace the lower absorbent layer 10201 in Example 1 and an upper polyester cotton layer to replace the upper absorbent layer 10202 in Example 1. Therefore, the moisture absorption and release of Example 1 are greater than the corresponding parameters of Comparative Example 4, and the moisture absorption rate of Example 1 is smaller than that of Comparative Example 4. Thus, the water absorption rate of Example 1 is faster than that of Comparative Example 4. This shows that when the number of absorbent layers and polyester cotton layers is equal, the absorbent layer can improve the moisture absorption, release, and water absorption rate of the humidity regulating sheet compared to the polyester cotton layer.

[0094] Compared with Comparative Example 4, Comparative Example 2's moisture absorption and release are smaller than those of Comparative Example 4 because the moisture-conditioning sheet obtained in Comparative Example 2 does not include the rubber moisture-conditioning layer 103. In addition, the moisture absorption rate of Comparative Example 2 is larger than that of Comparative Example 4, indicating that the water absorption rate of Comparative Example 2 is slower than that of Comparative Example 4. This also shows that without the rubber moisture-conditioning layer 103, the moisture absorption, release, and water absorption rate of the moisture-conditioning sheet will all be affected. Furthermore, since Comparative Example 2 only includes two polyester cotton layers and does not include the rubber moisture-conditioning layer 103, the moisture absorption is very small, and no flowing water will appear inside.

[0095] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a composite humidity-regulating sheet, characterized in that, Includes the following steps: S1. Preparation of absorbent solution: Mix polyol, metal salt and solvent, stir until the metal salt is completely dissolved, and then let stand for a period of time to obtain absorbent solution; S2. Preparation of absorbent layer: Select sheet-shaped polyester cotton, immerse the polyester cotton in the absorbent solution in step S1, and after the absorbent solution has completely soaked the polyester cotton, take it out and let it drain naturally, and then dry it to obtain polyester absorbent cotton. Cut the polyester absorbent cotton into the required size to obtain the absorbent layer. S3. Preparation of rubber moisture-conditioning layer: After the open mill is heated to a certain temperature, the raw rubber is first placed on the open mill for mixing and packaging for a period of time. Then, water-absorbing resin and polyol are added and mixed for a period of time. Then, vulcanizing agent is added and mixed for a period of time. After the mixing is completed, the obtained rubber mixture is pressed into sheets and left for a period of time to complete vulcanization, and water-absorbing rubber is obtained. The water-absorbing rubber is cut into the required size to obtain rubber moisture-conditioning layer (103). S4. Encapsulation of the composite humidity-regulating sheet: Select two absorbent layers and refer to them as the lower absorbent layer (10201) and the upper absorbent layer (10202), respectively. Select a sheet-like encapsulation layer (101) and a semi-permeable membrane layer (104). First, place the encapsulation layer (101), the lower absorbent layer (10201), the rubber humidity-regulating layer (103), the upper absorbent layer (10202), and the semi-permeable membrane layer (104) in sequence from bottom to top. Then, bond the edges of the encapsulation layer (101) and the semi-permeable membrane layer (104) together to encapsulate the lower absorbent layer (10201), the rubber humidity-regulating layer (103), and the upper absorbent layer (10202) to obtain the composite humidity-regulating sheet (1).

2. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S4: the rubber moisture-conditioning layer (103) consists of multiple pieces, and the multiple pieces of the rubber moisture-conditioning layer (103) are located between the lower absorbent layer (10201) and the upper absorbent layer (10202).

3. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S1: the polyol is 20-50 parts by weight, the metal salt is 2-5 parts by weight, and the solvent is 5-10 parts by weight; the polyol is selected from ethylene glycol, glycerol, butanethyl alcohol, and xylitol; the metal salt is selected from calcium chloride, sodium formate, and sodium acetate; and the solvent is deionized water.

4. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S2: the polyester cotton is woven and composited from polyester fiber and absorbent fiber. The polyester fiber is selected from polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). The absorbent fiber is selected from wood pulp, cellulose fiber, wood fiber, and viscose fiber.

5. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S3: the raw rubber is 40-80 parts by weight, the water-absorbing resin is 10-30 parts by weight, the polyol is 2-5 parts by weight, and the vulcanizing agent is 0.1-0.8 parts by weight; the raw rubber is selected from one of nitrile rubber, silicone rubber, and acrylate rubber; the water-absorbing resin is selected from one of starch-based water-absorbing resin, cellulose-based water-absorbing resin, and synthetic resin polyacrylate-based water-absorbing resin; the polyol is selected from one of ethylene glycol, glycerol, butanediol, and xylitol; and the vulcanizing agent is selected from one of trithiocyanate and peroxide.

6. The method for preparing a composite humidity-regulating sheet according to claim 5, characterized in that, In step S3: 0.1-0.8 parts by weight of a vulcanizing aid is added along with the vulcanizing agent; the vulcanizing aid is selected from sodium stearate, tetramethylthiuram disulfide, and benzothiazole disulfide.

7. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S4: the encapsulation layer (101) is selected from one of polyethylene terephthalate (PET) film, polyimide (PI) film, polyurethane (PU) film, and ethylene-tetrafluoroethylene copolymer (ETFE) film; the semi-permeable membrane layer (104) is selected from one of polytetrafluoroethylene semi-permeable membrane, polytetrafluoroethylene-polyethylene terephthalate composite semi-permeable membrane, and polyethylene-polypropylene composite semi-permeable membrane.

8. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S2: the thickness of the absorbent layer is 0.5-1mm; In step S3: the thickness of the rubber moisture-conditioning layer (103) is 0.5-2 mm; In step S4: the thickness of the encapsulation layer (101) is 0.1-0.5 mm, and the thickness of the semi-permeable membrane layer (104) is 0.1-0.5 mm; the areas of the encapsulation layer (101) and the semi-permeable membrane layer (104) are equal, the areas of the upper absorbent layer (10202), the rubber moisture-regulating layer (103), and the lower absorbent layer (10201) are equal, and the area of ​​the encapsulation layer (101) is greater than the area of ​​the rubber moisture-regulating layer (103); the edges of the encapsulation layer (101) and the semi-permeable membrane layer (104) are bonded together by hot pressing or ultrasonic welding.

9. The method for preparing a composite humidity-regulating sheet according to claim 1, characterized in that, In step S1: the settling time is 2-4 hours; In step S2: the drying temperature is 95-105℃ and the time is 4-8 hours; Step S3 is as follows: After the open mill is heated to 65-75℃, the raw rubber is first placed on the open mill for mixing and packaging for 5-15 minutes. Then, water-absorbing resin and polyol are added and mixing is continued for 5-15 minutes. Then, vulcanizing agent is added and mixing is continued for 5-15 minutes. After mixing, the obtained rubber mixture is pressed into sheets and left to stand for 18-30 hours to complete vulcanization, thus obtaining water-absorbing rubber. The water-absorbing rubber is cut into the required size to obtain the rubber moisture-conditioning layer (103).

10. A composite humidity-regulating sheet, prepared using the method for preparing a composite humidity-regulating sheet as described in any one of claims 1-9, characterized in that: The package includes, from bottom to top, an encapsulation layer (101), a lower absorbent layer (10201), a rubber moisture-regulating layer (103), an upper absorbent layer (10202), and a semi-permeable membrane layer (104). The edges of the encapsulation layer (101) and the semi-permeable membrane layer (104) are bonded together to encapsulate the lower absorbent layer (10201), the rubber moisture-regulating layer (103), and the upper absorbent layer (10202) between the semi-permeable membrane layer (104) and the encapsulation layer (101).

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