A negative ion diaphragm and a method for manufacturing the same

Abstract

The present application relates to a kind of negative ion diaphragm and its preparation method, which is prepared by first preparing the base material layer added with negative ion ore nano powder, then coating a negative ion ore nano functional layer on one side of the base material layer, and coating a adhesive layer added with negative ion ore nano powder on the other side of the base material layer, to form a negative ion film with three layers of negative ion functional layer / negative ion base material layer / negative ion adhesive layer all containing negative ion ore nano powder.The preparation method can load more negative ion ore nano powder that can generate negative oxygen ions on the inherent area of negative ion diaphragm without affecting the air permeability, water absorption and transmittance of the film, thereby improving the air purification efficiency.

Description

Technical Field

[0001] This invention belongs to the field of functional membrane preparation, specifically relating to a negative ion separator and its preparation method. Background Technology

[0002] With industrial development and population growth, air pollution has become an increasingly serious problem. Harmful substances in the air, such as particulate matter, sulfur dioxide, nitrogen oxides, and carbon monoxide, pose a significant threat to human health. Therefore, air purification technology has become an important research direction in the environmental protection field. Currently, the World Health Organization defines fresh air as containing 1000-1500 negative oxygen ions per cubic centimeter. Negative ion technology has received widespread attention due to its ability to effectively remove harmful substances from the air and its advantages in purifying the air, sterilizing and disinfecting, and regulating human physiological functions.

[0003] Existing negative ion air purification technologies mainly include negative ion generators and negative ion adsorption materials. Negative ion generators ionize water molecules in the air through corona discharge, producing negative ions. These negative ions can combine with harmful substances in the air to form harmless substances, thus purifying the air. However, negative ion generators produce secondary pollutants such as ozone during operation, posing a potential threat to human health. Negative ion adsorption materials adsorb harmful substances in the air through physical or chemical means, fixing them to the material surface to purify the air. However, negative ion adsorption materials are prone to saturation during use, requiring frequent replacement and increasing operating costs. Therefore, a negative ion membrane has been proposed to address the problems of secondary pollutants such as ozone generated when using negative ion generators or negative ion adsorption materials, as well as the high operating costs.

[0004] Chinese patent CN111721052A discloses a method for preparing a negative ion formaldehyde-removing glass heat-insulating film. The method involves coating a heat-insulating layer onto the surface of a transparent film substrate; then coating a layer of negative ion mixture onto the heat-insulating layer; placing the film in an environment at 105℃ for 125 seconds to cure, forming a negative ion coating. The negative ion mixture is composed of tourmaline negative ion powder, modified brucite powder, titanium dioxide, silane coupling agent, and polyurethane adhesive; finally, a protective film is coated onto the negative ion coating. The negative ion formaldehyde-removing glass film prepared by this method generates a limited number of negative ions per unit time, resulting in low purification efficiency. Furthermore, it only uses tourmaline negative ion powder as the mineral for generating negative ions, meaning it cannot generate negative ions in other scenarios where the conditions for tourmaline to generate negative ions are not met, thus limiting its applicable purification scenarios and failing to meet people's high-quality air purification needs in an increasingly severe air pollution environment. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a negative ion separator.

[0006] The method for preparing a negative ion separator according to the present invention includes the following steps:

[0007] Modified negative ion nanoparticles are added to the substrate raw materials to prepare a negative ion-based material slurry, and a negative ion substrate layer is prepared by coating the negative ion-based material slurry.

[0008] A layer of negative ion functional slurry containing modified negative ion nanoparticles is coated on one side of the negative ion substrate layer to form a negative ion functional layer.

[0009] A layer of adhesive containing modified negative ion nanoparticles is coated on the other side of the negative ion substrate layer to form a negative ion adhesive layer.

[0010] A release film is bonded onto the negative ion adhesive layer to prepare a negative ion membrane consisting of a negative ion functional layer, a negative ion substrate layer, a negative ion adhesive layer, and a release layer.

[0011] Compared with existing technologies, the negative ion membrane preparation method provided by this invention involves first preparing a substrate layer with added negative ion mineral nanoparticles, then coating one side of the substrate layer with a negative ion mineral nanoparticle functional layer and the other side of the substrate layer with an adhesive layer containing added negative ion mineral nanoparticles. This creates a negative ion membrane with three layers containing negative ion mineral nanoparticles: the negative ion functional layer, the negative ion substrate layer, and the negative ion adhesive layer. This preparation method maximizes the loading of more negative ion mineral nanoparticles that can generate negative oxygen ions on a negative ion membrane of a fixed area without affecting the membrane's air permeability, water absorption, and permeability, thereby improving air purification efficiency.

[0012] Furthermore, the negative ion substrate layer is prepared as follows:

[0013] SA1 adds 10% to 20% by mass of modified negative ion nanopowder to the base material to prepare a negative ion-based material slurry.

[0014] SA2 sequentially stirs, vacuum degasses, and allows to stand to defoam before preparing a negative ion substrate layer by coating.

[0015] Furthermore, the substrate is TPU, TAC, or SRF.

[0016] Furthermore, the negative ion functional slurry is prepared as follows:

[0017] SC1 adds 10% to 20% by weight of modified negative ion nanoparticles to PU resin to prepare a resin mixture;

[0018] SC2 adds 200% isopropanol solvent to the resin mixture to prepare a functional slurry;

[0019] After SC3 sequentially stirs, vacuum degasses, and allows to stand for defoaming, it yields a negative ion functional slurry.

[0020] Furthermore, the adhesive with added modified negative ion nanoparticles is prepared as follows:

[0021] SD1 adds 20% to 30% by weight of modified negative ion nanoparticles to the adhesive to prepare an adhesive mixture;

[0022] SD2 adds 50% ester solvent to the adhesive mixture to make an adhesive slurry;

[0023] SD3 was used to stir the adhesive slurry to obtain an adhesive with modified negative ion nanoparticles.

[0024] Furthermore, the preparation method of modified negative ion nanopowder is as follows:

[0025] S1 converts ductile iron ore with negative ion generation capability into negative ion ore nanopowder.

[0026] S2 adds a modifier to negative ion mineral nanopowder, and after mixing, stirring, high-temperature heating and natural cooling, modified negative ion nanopowder is obtained.

[0027] Furthermore, the ore with negative ion generating ability is one or more of the following: Tian Shou stone, Hexagonal stone, and Seagull stone.

[0028] Furthermore, the particle size of the negative ion mineral nanoparticles includes three particle size grades: 0.002mm~0.005mm, 0.006mm~0.01mm, and 0.011~0.05mm, respectively, and the maximum particle size does not exceed the thickness of the substrate.

[0029] Furthermore, the modifier is one or more of cerium, titanium oxides or hydroxides.

[0030] Meanwhile, the present invention also provides a negative ion membrane, which is prepared by any of the above preparation methods and has a negative ion functional layer / negative ion substrate layer / negative ion adhesive layer / release layer structure.

[0031] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the preparation process according to an embodiment of the present invention;

[0033] Figure 2This is a schematic diagram of the negative ion membrane prepared according to the present invention. Detailed Implementation

[0034] To facilitate understanding of the present invention, a more comprehensive and detailed description of the present invention will be provided below, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0035] To address the problem of limited negative ion generation and low purification efficiency of negative ion membranes prepared by existing methods, this invention presents a method for preparing a negative ion membrane. This method involves first preparing a substrate layer incorporating negative ion mineral nanoparticles, then coating one side of the substrate layer with a negative ion mineral nanoparticle functional layer, and finally coating the other side with an adhesive layer containing negative ion mineral nanoparticles. This creates a negative ion membrane where all three layers—the functional layer, the substrate layer, and the adhesive layer—contain negative ion mineral nanoparticles. This method maximizes the loading of negative ion-generating mineral nanoparticles onto the negative ion membrane within its inherent area, without affecting its air permeability, water absorption, or permeability, thereby improving air purification efficiency.

[0036] Please see Figure 1 and Figure 2 The following describes the preparation method of the negative ion membrane of this application, including the following steps.

[0037] (I) Preparation of modified negative ion nanopowder

[0038] S1 converts ductile iron ore with negative ion generation capability into negative ion mineral nanopowder.

[0039] The ductile iron equipment includes a three-roll mill and a high-speed ball mill.

[0040] The ore with negative ion generating capability is one or more of the following: Tian Shou stone, Hexagonal stone, and Seagull stone. A combination of multiple ores with different negative ion generating mechanisms is preferred to ensure that at least one ore can generate negative ions in different application scenarios.

[0041] The negative ion mineral nanopowder has three particle size grades: 0.002mm~0.005mm, 0.006mm~0.01mm, and 0.011~0.05mm, respectively, and its maximum particle size does not exceed the thickness of the substrate.

[0042] In a combination of multiple ores, all ores have the same particle size grade. In a combination of multiple ores, all ores have the same mass ratio.

[0043] S2 adds a modifier to negative ion mineral nanopowder, and after mixing, stirring, high-temperature heating and natural cooling, modified negative ion nanopowder is obtained.

[0044] The modifier is one or more of cerium, titanium oxides or hydroxides. This modifier can catalyze and increase the rate at which negative ion mineral nanoparticles generate negative ions.

[0045] The heating temperature for the high-temperature heating is 550℃~650℃, preferably 600℃; the heating time is 4 hours~6 hours, preferably 5 hours.

[0046] The content of the modifier is 3% to 6% of the mass percentage of the negative ion mineral nanopowder.

[0047] (II) Preparation of negative ion membrane

[0048] S3 adds modified negative ion nanoparticles to the substrate raw materials to make a negative ion-based material slurry, and then prepares a negative ion substrate layer by coating the negative ion-based material slurry.

[0049] Specifically, the following steps are included:

[0050] SA1 adds 10% to 20% by mass of the modified negative ion nanopowder prepared in step S2 to the substrate raw material to make a negative ion-based material slurry.

[0051] SA2 sequentially stirs, vacuum degasses, and allows to stand to defoam before preparing a negative ion substrate layer by coating.

[0052] The substrate is TPU, TAC, or SRF. TPU is preferred as the substrate, and the raw materials for TPU are polyols, polyisocyanates, and other polymeric materials. When using TPU as the substrate, gaps exist in the arrangement of mineral particles of the same size. Furthermore, TPU itself has good air permeability, allowing air to enter the TPU and electrolyze with the mineral particles inside, generating and releasing negative ions.

[0053] The settling time is 20 to 30 minutes.

[0054] The thickness of the negative ion substrate layer is 0.05 mm to 0.2 mm.

[0055] S4 coats one side of the negative ion substrate layer with a layer of negative ion functional slurry containing modified negative ion nanoparticles to form a negative ion functional layer.

[0056] The negative ion functional slurry is prepared by the following method:

[0057] SC1 adds 10% to 20% by mass of the modified negative ion nanoparticles prepared in step S2 to PU resin to form a resin mixture;

[0058] SC2 adds 200% by weight of isopropanol solvent to the resin mixture to prepare a functional slurry;

[0059] After SC3 sequentially stirs, vacuum degasses, and allows to stand for defoaming, it yields a negative ion functional slurry.

[0060] The thickness of the PU resin adhesive coating is 0.005mm to 0.01mm, which only adheres to the bottom part of the raw ore, so that the raw ore powder on the film surface can be exposed to the air with the maximum bareness. This allows the raw ore powder to have 100% unobstructed contact with the air, and can generate negative ions through electrolysis in the largest amount and for a long time, and can be completely released into the air.

[0061] The thickness of the negative ion functional layer is 0.02mm to 0.05mm.

[0062] S5 coats an adhesive containing modified negative ion nanoparticles on the other side of the negative ion substrate layer to form a negative ion adhesive layer, thus preparing a negative ion membrane consisting of a negative ion functional layer / negative ion substrate layer / negative ion adhesive layer.

[0063] The adhesive with added modified negative ion nanoparticles is prepared by the following method:

[0064] SD1 adds 20% to 30% by mass of the modified negative ion nanoparticles prepared in step S2 to the adhesive to make an adhesive mixture;

[0065] SD2 adds 50% by weight of ester solvent to the adhesive mixture to prepare adhesive slurry;

[0066] SD3 was used to stir the adhesive slurry to obtain an adhesive with modified negative ion nanoparticles.

[0067] The adhesive is a low-VOC, high-temperature resistant adhesive.

[0068] The thickness of the negative ion adhesive layer is 0.015mm-0.5mm.

[0069] S6 After baking the negative ion membrane prepared in step S5 (negative ion functional layer / negative ion substrate layer / negative ion adhesive layer), a release film is attached to the negative ion adhesive layer to prepare a negative ion membrane (negative ion functional layer / negative ion substrate layer / negative ion adhesive layer / release layer).

[0070] The release film is a PET film.

[0071] The thickness of the release film is 0.025mm-0.2mm.

[0072] The technical solutions and effects of the present invention will be further explained below with reference to embodiments and comparative examples.

[0073] It should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0074] Example 1

[0075] In this embodiment, the negative ion membrane is prepared according to the following method.

[0076] S1. 1000g of Tian Shou stone, 1000g of Liu Huan stone, and 1000g of Hai Gu stone are spheroidized into 0.002mm to 0.05mm mineral nanoparticles using a three-roll mill and a high-speed ball mill, respectively. The Tian Shou stone nanoparticles, Liu Huan stone nanoparticles, and Hai Gu stone nanoparticles with the same particle size of 0.002mm to 0.005mm are then mixed together in a mass ratio of 1:1:1 to form negative ion mineral nanoparticles.

[0077] S2 adds 3% cerium oxide to negative ion mineral nanopowder, and after mixing and stirring, heating at 600℃ for 5 hours and natural cooling, modified negative ion nanopowder is obtained.

[0078] S3 prepared a negative ion-based material slurry using a mass ratio of TPU raw material to modified negative ion nanopowder of 80% to 20%. The negative ion-based material slurry was then stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam before being coated to prepare a negative ion substrate layer with a thickness of 0.05 mm.

[0079] S4 prepared a functional slurry with a mass ratio of PU resin: modified negative ion nanoparticles: isopropanol solvent = 80%: 20%: 200%; the functional slurry was stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam, and then a negative ion functional layer with a thickness of 0.02 mm was prepared on the negative ion substrate layer by coating.

[0080] S5 prepared an adhesive mixture with a mass ratio of adhesive: modified negative ion nanoparticles: lipid solvent = 70%: 30%: 50%; a layer of adhesive mixture with a thickness of 0.02 mm was coated on the side of the negative ion substrate layer that was not coated with the negative ion functional layer to form a negative ion adhesive layer, thus preparing a negative ion membrane with negative ion functional layer / negative ion substrate layer / negative ion adhesive layer.

[0081] S6 After baking the negative ion membrane prepared in step S5 (negative ion functional layer / negative ion substrate layer / negative ion adhesive layer) at 105°C for 3 minutes, the release film is then bonded to the negative ion adhesive layer to prepare the negative ion membrane.

[0082] Example 2

[0083] In this embodiment, the negative ion membrane is prepared according to the following method.

[0084] S1. 1000g of Tian Shou stone, 1000g of Liu Huan stone, and 1000g of Hai Gu stone are spherically ground into 0.002mm to 0.05mm mineral nanoparticles using a three-roll mill and a high-speed ball mill, respectively. Tian Shou stone nanoparticles, Liu Huan stone nanoparticles, and Hai Gu stone nanoparticles with the same particle size of 0.006mm to 0.01mm are then mixed together in a 1:1:1 mass ratio to form negative ion mineral nanoparticles.

[0085] S2 adds 5% titanium oxide to negative ion mineral nanoparticles, and after mixing and stirring, heating at 600℃ for 5 hours and natural cooling, modified negative ion nanoparticles are obtained.

[0086] S3 prepared a negative ion-based material slurry using TPU raw materials and modified negative ion nanopowder in a mass ratio of 85% to 15%. The negative ion-based material slurry was then stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam before being coated to form a negative ion substrate layer with a thickness of 0.05 mm.

[0087] S4 prepared a functional slurry with a mass ratio of PU resin: modified negative ion nanoparticles: isopropanol solvent = 85%: 15%: 200%; the functional slurry was stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam, and then coated onto the negative ion substrate layer to prepare a negative ion functional layer with a thickness of 0.03 mm.

[0088] S5 prepared an adhesive mixture with a mass ratio of adhesive: modified negative ion nanoparticles: lipid solvent = 75%: 25%: 50%; a layer of adhesive mixture with a thickness of 0.03 mm was coated on the side of the negative ion substrate layer that was not coated with the negative ion functional layer to form a negative ion adhesive layer, thus preparing a negative ion membrane with negative ion functional layer / negative ion substrate layer / negative ion adhesive layer.

[0089] S6 After baking the negative ion membrane prepared in step S5 (negative ion functional layer / negative ion substrate layer / negative ion adhesive layer) at 105°C for 3 minutes, the release film is then bonded to the negative ion adhesive layer to prepare the negative ion membrane.

[0090] Example 3

[0091] In this embodiment, the negative ion membrane is prepared according to the following method.

[0092] S1. 1000g of Tian Shou stone, 1000g of Liu Huan stone, and 1000g of Hai Gu stone are spheroidized into 0.002mm to 0.05mm mineral nanoparticles using a three-roll mill and a high-speed ball mill, respectively. Tian Shou stone nanoparticles, Liu Huan stone nanoparticles, and Hai Gu stone nanoparticles with the same particle size of 0.011 to 0.05mm are then mixed together in a 1:1:1 mass ratio to form negative ion mineral nanoparticles.

[0093] S2 adds 6% cerium hydroxide to negative ion mineral nanopowder, and after mixing and stirring, heating at 600℃ for 5 hours and natural cooling, modified negative ion nanopowder is obtained.

[0094] S3 prepared a negative ion-based material slurry using a mass ratio of TPU raw material to modified negative ion nanopowder of 90% to 10%. The negative ion-based material slurry was then stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam before being coated to form a negative ion substrate layer with a thickness of 0.05 mm.

[0095] S4 prepared a functional slurry with a mass ratio of PU resin: modified negative ion nanoparticles: isopropanol solvent = 90%: 10%: 200%; the functional slurry was stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam, and then a negative ion functional layer with a thickness of 0.05 mm was prepared on the negative ion substrate layer by coating.

[0096] S5 prepares an adhesive mixture with a mass ratio of adhesive: modified negative ion nanoparticles: lipid solvent = 80%: 20%: 50%; a layer of adhesive mixture with a thickness of 0.05 mm is coated on the side of the negative ion substrate layer that is not coated with the negative ion functional layer to form a negative ion adhesive layer, thus preparing a negative ion membrane with negative ion functional layer / negative ion substrate layer / negative ion adhesive layer.

[0097] S6 After baking the negative ion membrane prepared in step S5 (negative ion functional layer / negative ion substrate layer / negative ion adhesive layer) at 105°C for 3 minutes, the release film is then bonded to the negative ion adhesive layer to prepare the negative ion membrane.

[0098] Comparative Example 1

[0099] S1` uses a three-roll mill and a high-speed ball mill to grind 1000g of tourmaline into tourmaline nanoparticles with a particle size of 0.002mm to 0.05mm. The particles with a particle size of 0.011 to 0.05mm are then screened to form negative ion mineral nanoparticles.

[0100] S3' is prepared by coating a TPU substrate layer with a thickness of 0.05 mm.

[0101] S4 prepared a functional slurry with a mass ratio of PU resin: tourmaline nanopowder: isopropanol solvent = 90%: 10%: 200%; the functional slurry was stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam, and then coated onto a TPU substrate layer to prepare a negative ion functional layer with a thickness of 0.05 mm.

[0102] S5' prepared an adhesive mixture with a mass ratio of adhesive to lipid solvent of 100% to 50%; a layer of adhesive mixture with a thickness of 0.05mm was coated on the side of the TPU substrate layer that was not coated with the negative ion functional layer to form an adhesive layer, thus preparing a negative ion membrane of tourmaline functional layer / substrate layer / adhesive layer.

[0103] S6 After baking the negative ion membrane with negative ion functional layer / substrate layer / adhesive layer prepared in step S5 at 105℃ for 3 minutes, the release film is bonded to the negative ion adhesive layer to prepare the negative ion membrane.

[0104] Comparative Example 2

[0105] S1. 1000g of Tian Shou stone, 1000g of Liu Huan stone, and 1000g of Hai Gu stone are spheroidized into 0.002mm to 0.05mm mineral nanoparticles using a three-roll mill and a high-speed ball mill, respectively. Tian Shou stone nanoparticles, Liu Huan stone nanoparticles, and Hai Gu stone nanoparticles with the same particle size of 0.011 to 0.05mm are then mixed together in a mass ratio of 1:1:1 to form negative ion mineral nanoparticles.

[0106] S2 adds 6% cerium hydroxide to negative ion mineral nanopowder, and after mixing and stirring, heating at 600℃ for 5 hours and natural cooling, modified negative ion nanopowder is obtained.

[0107] S3' is prepared by coating a TPU substrate layer with a thickness of 0.05 mm.

[0108] S4 prepared a functional slurry with a mass ratio of PU resin: modified negative ion nanoparticles: isopropanol solvent = 90%: 10%: 200%; the functional slurry was stirred, vacuum degassed, and allowed to stand for 20 minutes to defoam, and then coated onto a TPU substrate layer to prepare a negative ion functional layer with a thickness of 0.05 mm.

[0109] S5' Prepares an adhesive mixture with a mass ratio of adhesive to lipid solvent of 100% to 50%; Coat a layer of adhesive mixture with a thickness of 0.05mm on the side of the TPU substrate layer that is not coated with the negative ion functional layer to form an adhesive layer, thus preparing a negative ion membrane of negative ion functional layer / substrate layer / adhesive layer.

[0110] S6 After baking the negative ion membrane with negative ion functional layer / substrate layer / adhesive layer prepared in step S5 at 105℃ for 3 minutes, the release film is bonded to the negative ion adhesive layer to prepare the negative ion membrane.

[0111] Results Test Analysis

[0112] The negative ion membranes prepared in Examples 1 to 3 and the composite coatings prepared in the comparative examples were tested and analyzed for negative ion and formaldehyde concentrations. The test results are shown in Table 1.

[0113] Test environment conditions: temperature 15℃~35℃, relative humidity 40%~60%.

[0114] Test equipment and test conditions:

[0115] 1. Negative ions

[0116] Testing equipment: negative ion tester, breathable standard chamber with dimensions of 500mm*500mm*500mm;

[0117] Testing environment: Indoor environment with formaldehyde concentration exceeding 1 mg / m3;

[0118] Test method:

[0119] 1) Prepare the above-mentioned breathable standard box, place the negative ion tester in the middle of the bottom of the box and turn it on to test the background negative ion content. After waiting for 1 hour, record the background negative ion content.

[0120] 2) The negative ion membrane prepared by the method of the present invention is attached to one side of the inner wall of the air-permeable standard box. The negative ion tester is placed in the middle of the bottom of the box and turned on to test the negative ion content of the sample. After waiting for 1 hour, the negative ion content of the negative ion membrane sample is recorded.

[0121] 2. Formaldehyde concentration

[0122] Testing equipment: air quality monitor, and a standard breathable enclosure with dimensions of 500mm*500mm*500mm;

[0123] Testing environment: Indoor environment with formaldehyde concentration exceeding 1 mg / m3;

[0124] Test method:

[0125] 1) Prepare the above-mentioned breathable standard chamber, place the air monitor in the middle of the bottom of the chamber and turn it on to test the background formaldehyde concentration. After waiting for 1 hour, record the background formaldehyde concentration.

[0126] 2) The negative ion membrane prepared by the method of the present invention is attached to one side of the inner wall of the air-permeable standard box. The air monitor is placed in the middle of the bottom of the box and turned on to test the formaldehyde concentration of the sample. After waiting for 1 hour, the formaldehyde concentration of the negative ion membrane sample is recorded.

[0127] Table 1

[0128]

[0129] The performance characterization test results in Table 1 are analyzed.

[0130] The above data demonstrate that the modified negative ion nanoparticles prepared in this invention exhibit superior negative ion generation and formaldehyde purification capabilities compared to commercially available mineral nanoparticles. The negative ion membrane prepared in this invention, based on the addition of mineral powders to both the substrate and adhesive layer, possesses superior negative ion generation and formaldehyde purification capabilities. It can maximize the loading of more negative ion-generating mineral nanoparticles without affecting the membrane's air permeability, water absorption, or permeability, thereby improving air purification efficiency.

[0131] This invention is not limited to the above-described embodiments. If any modifications or variations to this invention do not depart from the spirit and scope of this invention, and if such modifications and variations fall within the scope of the claims and equivalent technologies of this invention, then this invention also intends to include such modifications and variations.

Claims

1. A method for preparing a negative ion separator, characterized in that, Includes the following steps: Add 10% to 20% by mass of modified negative ion nanopowder to the substrate raw material to prepare a negative ion-based material slurry, and then prepare a negative ion substrate layer by coating the negative ion-based material slurry. A layer of negative ion functional slurry containing 10% to 20% modified negative ion nanopowder by mass is coated on one side of the negative ion substrate layer to form a negative ion functional layer. A layer of adhesive containing 20% ​​to 30% by mass of modified negative ion nanoparticles is coated on the other side of the negative ion substrate layer to form a negative ion adhesive layer. A release film is bonded onto the negative ion adhesive layer to prepare a negative ion membrane consisting of a negative ion functional layer, a negative ion substrate layer, a negative ion adhesive layer, and a release layer. The preparation method of the modified negative ion nanopowder is as follows: S1. A ore with negative ion generating ability is ball-milled into negative ion ore nanopowder; the ore with negative ion generating ability is one or more of the following: Tian Shou stone, Hexagonal stone, and Seagull stone; the particle size of the negative ion ore nanopowder is selected from one of three particle size grades: 0.002mm~0.005mm, 0.006mm~0.01mm, and 0.011mm~0.05mm, and its maximum particle size does not exceed the thickness of the substrate; the particle size grades of each ore in the combination of multiple ores are the same. S2 Adds a modifier to negative ion mineral nanopowder, and after mixing, stirring, high-temperature heating and natural cooling, modified negative ion nanopowder is obtained; the modifier is one or more of cerium, titanium oxides or hydroxides; the high-temperature heating temperature is 550℃~650℃.

2. The preparation method according to claim 1, characterized in that, The negative ion substrate layer is prepared as follows: SA1 adds 10% to 20% by mass of modified negative ion nanopowder to the base material to make a negative ion-based material slurry. SA2 involves sequentially stirring, vacuum degassing, and allowing the negative ion-based material slurry to stand for defoaming before preparing a negative ion substrate layer by coating.

3. The preparation method according to claim 2, characterized in that, The substrate is TPU or TAC.

4. The preparation method according to claim 1, characterized in that, The negative ion functional slurry is prepared as follows: SC1 adds 10%~20% by weight of modified negative ion nanoparticles to PU resin to prepare a resin mixture; SC2 adds 200% isopropanol solvent to the resin mixture to prepare a functional slurry; SC3 sequentially stirs, vacuum degasses, and allows to stand for defoaming to obtain a negative ion functional slurry.

5. The preparation method according to claim 1, characterized in that, The adhesive with added modified negative ion nanoparticles is prepared as follows: SD1 adds 20% to 30% by weight of modified negative ion nanoparticles to the adhesive to prepare an adhesive mixture; SD2 adds 50% ester solvent to the adhesive mixture to make an adhesive slurry; SD3 is used to stir the adhesive slurry to obtain an adhesive with modified negative ion nanoparticles.

6. A negative ion separator, characterized in that, It includes a negative ion functional layer / negative ion substrate layer / negative ion adhesive layer / release layer structure prepared by the preparation method according to any one of claims 1 to 5.

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