Mask filter material with ion adsorption and particulate filtration functions and preparation method thereof

Abstract

The application discloses a mask filter material with ion adsorption and particle filtration functions and a preparation method thereof, and belongs to the technical field of mask products. The mask filter material is composed of a wet non-woven fabric and a polytetrafluoroethylene microporous membrane through thermal bonding. The wet non-woven fabric layer is prepared from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers and cellulose fibers through a wet laying technology. In addition to effectively filtering bacteria, viruses and other solid and liquid particle matters in the air, the mask filter material can also effectively adsorb harmful gases such as sulfur oxides, nitrogen oxides, ammonia and formaldehyde in the air.

Description

Technical Field

[0001] This invention relates to the field of mask product technology, and more specifically to a mask filter material with both ion adsorption and particulate filtration functions and its preparation method. Background Technology

[0002] Early masks were mainly used for warmth and protection against the cold; in some dusty workplaces, masks were also used to prevent dust exposure.

[0003] Early masks were mainly made of cotton gauze, which excelled in warmth but had poor filtration of fine dust (such as PM2.5) and lacked the ability to filter harmful gases. Later, masks made of electrostatically charged polypropylene meltblown nonwoven fabric were invented. These masks primarily function through physical filtration via micropores and electrostatic adsorption, significantly increasing their filtration capacity for fine particles (including solid, liquid, or mixed solid-liquid particles in the air). For example, CN104305591B utilizes the filtration performance of electrospun nanofiber membranes and the adsorption performance of carbon nanotube hollow lattices to simultaneously filter PM2.5 fine particles and adsorb toxic and harmful substances. However, it still lacks the ability to filter harmful gases, and the attached static electricity can easily cause skin allergies.

[0004] Further research has led to the development of masks made from polytetrafluoroethylene (PTFE) nanoporous membranes. These masks significantly increase the physical filtration effect on fine particles and eliminate the need for electret electrostatics; however, they lack the ability to filter harmful gases. In addition, researchers are attempting to create masks with sterilization functions using graphene or other antibacterial materials to prevent bacterial and viral infections. For example, the mask provided by CN106474640B uses nano-antibacterial materials with a larger specific surface area, allowing for greater contact with bacteria and resulting in a higher sterilization effect; however, it still cannot completely eliminate the harm caused by harmful gases in the air. Summary of the Invention

[0005] To address the above problems, this invention provides a mask filter material that combines ion adsorption and particulate filtration, as well as its preparation method. In addition to effectively filtering bacteria, viruses, and other solid and liquid particulate matter in the air, it can also effectively adsorb harmful gases such as sulfur oxides, nitrogen oxides, ammonia, and formaldehyde in the air.

[0006] The first objective of this invention is to provide a mask filter material that combines ion adsorption and particulate filtration functions, characterized in that it is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0007] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cellulose fibers.

[0008] Preferably, the cation exchange fiber containing carboxyl groups is obtained by radiation grafting using polyolefin fiber as the base material and acrylic acid aqueous solution as the grafting solution;

[0009] The absorbed dose of the electron beam irradiation is 20-60 kGy; the mass percentage of the acrylic acid aqueous solution is 10-15%; the amount of acrylic acid aqueous solution used is 3-5 times the mass of the polyolefin fiber;

[0010] The cation exchange fibers containing carboxyl groups have a fineness of 0.5–1.5D and a length of 3–6 mm.

[0011] Preferably, the anion exchange fiber containing amine groups is obtained by radiation grafting using polyolefin fiber as the base material and dimethylaminoacrylate aqueous solution as the grafting solution;

[0012] The absorbed dose of the electron beam irradiation is 20-60 kGy; the mass percentage of the dimethylaminoacrylate aqueous solution is 15-20%; the amount of dimethylaminoacrylate aqueous solution used is 3-5 times the mass of the polyolefin fiber;

[0013] The anion exchange fibers containing amine groups have a fineness of 0.5–1.5D and a length of 3–6 mm.

[0014] Preferably, the polyolefin fiber is a core-sheath composite fiber composed of polyethylene and polypropylene. Its core layer is polypropylene; its sheath layer is polyethylene; the polyolefin fiber has a fineness of 0.5–1.5D and a length of 3–6 mm.

[0015] Preferably, the cellulose fiber is one or more of the following: coniferous wood pulp fiber, cotton cellulose fiber, viscose fiber, and Tencel fiber.

[0016] The second objective of this invention is to provide a method for preparing the above-mentioned mask filter material that combines ion adsorption and particulate filtration functions, which is prepared according to the following steps:

[0017] S1. A mixture of cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cellulose fibers is obtained. The mixture fibers are then dispersed in water to form a slurry.

[0018] S2. The slurry is fed into a wet-laid inclined wire forming machine, where it is filtered and deposited to form a wet fiber membrane. The membrane is then dried and shaped to produce a highly uniform wet-laid nonwoven fabric.

[0019] S3. A mask filter material with both ion adsorption and particulate filtration is prepared by thermally bonding wet nonwoven fabric with polytetrafluoroethylene nanoporous membrane.

[0020] Preferably, in S1, the mass concentration of the mixed fibers in the slurry is 0.01-0.1%;

[0021] The mixed fiber is composed of the following raw materials in the following mass percentages: 20-30% cation exchange fiber containing carboxyl groups, 30-40% anion exchange fiber containing amine groups, 10-30% polyolefin fiber, and the remainder is cellulose fiber.

[0022] Preferably, in S2, the drying method is a tunnel oven or hot cylinder drying and shaping; the areal density of the wet-laid nonwoven fabric is 20-40 g / m². 2 .

[0023] Preferably, in S3, the polytetrafluoroethylene nanoporous membrane has a nano-sized microporous structure with an areal density of 0.5–2.0 g / m³. 2 Breathability is 3-6m 3 / m·min;

[0024] Wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane are laminated together and thermally bonded using a thermal laminating machine equipped with felt pressure belts and pressure rollers; the thermal bonding temperature is 110-150℃ and the pressure of the pressure rollers is 2-5MPa.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a multifunctional mask filter material that combines ion adsorption and particulate filtration. The mask filter material mainly consists of a wet-laid nonwoven fabric layer containing ion exchange fibers and a polytetrafluoroethylene nanoporous membrane layer. In the wet-laid nonwoven fabric layer, the carboxyl-containing cation exchange fibers are obtained by radiation grafting acrylic acid onto polyolefin fibers. After modification, they carry carboxyl ion exchange groups, allowing them to adsorb harmful gases such as ammonia through ion exchange. The amine-containing anion exchange fibers are made by radiation grafting dimethylaminoacrylate onto polyolefin fibers. After modification, they carry amine ion exchange groups, allowing them to adsorb harmful gases such as nitrogen oxides and sulfur oxides. The polyolefin fibers mainly play a bonding and fixing role in the nonwoven fabric. The cellulose fibers, rich in hydroxyl groups on their surface, can adsorb formaldehyde through reaction with formaldehyde. Furthermore, since these fibers are natural biomass materials, the mask filter material prepared from them is bio-friendly, will not cause discomfort to human skin, and has better wearing comfort.

[0027] The mask filter material prepared by this invention can not only effectively filter bacteria, viruses and other solid and liquid particulate matter in the air, but also effectively adsorb harmful gases such as sulfur oxides, nitrogen oxides, ammonia and formaldehyde in the air, thereby providing better air purification function. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The filtration efficiency in the following examples refers to the overall filtration effect on bacteria, viruses and other solid and liquid particulate matter.

[0030] The coniferous wood pulp fiber, cotton cellulose fiber, viscose fiber, Tencel fiber, and polyolefin fiber used in the following examples are all commercially available. Conventional polyolefin fiber is a core-sheath composite fiber composed of polyethylene (PE) and polypropylene (PP). Its core layer is polypropylene (PP), which acts as a skeleton; its sheath layer is polyethylene (PE), which provides thermal bonding.

[0031] The polytetrafluoroethylene nanoporous membrane used in this invention has a nanoscale microporous structure with an areal density of 0.5–2.0 g / m³. 2 Breathability is 3-6m 3 / m·min.

[0032] Example 1

[0033] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0034] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and softwood pulp fibers.

[0035] The mask filter material is prepared according to the following steps:

[0036] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, spread them evenly in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 60KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 10% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 5 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0037] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0038] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0039] The ion exchange capacity of the prepared carboxyl-containing cation exchange fiber was 4.02 mmol / g.

[0040] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain weight of polyolefin fibers with a fineness of 0.5D and a length of 3mm, evenly spread them in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 60KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 20% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0041] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0042] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0043] The ion exchange capacity of the prepared anion exchange fiber containing amine groups was 2.26 mmol / g.

[0044] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 0.5D and a length of 3mm, and softwood pulp fiber prepared above are mixed to obtain mixed fiber. The mixed fiber is then dispersed in water to make a slurry. The concentration of the mixed fiber in the slurry is 0.01%.

[0045] The mixed fiber is composed of the following raw materials in the following mass percentages: 30% cation exchange fiber containing carboxyl groups, 30% anion exchange fiber containing amine groups, 30% polyolefin fiber, and 10% softwood pulp fiber.

[0046] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a tunnel oven at 130°C to produce a highly uniform wet-laid nonwoven fabric with a surface density of 20–40 g / m². 2 between.

[0047] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and pressure rollers to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 110℃, and the pressure of the pressure rollers is 2MPa. The areal density of the prepared mask filter material is 20.5~42.0g / m³. 2 Breathability is 3-6m 3 / m·min, with a filtration efficiency of 99.57%.

[0048] Example 2

[0049] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0050] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and Tencel fibers.

[0051] The mask filter material is prepared according to the following steps:

[0052] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, spread them evenly in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 20KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 15% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0053] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0054] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0055] The ion exchange capacity of the prepared carboxyl-containing cation exchange fiber was 3.73 mmol / g.

[0056] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, evenly spread them in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 20KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 15% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 5 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Heat the glass reactor in a 60℃ constant temperature water bath for 6 hours.

[0057] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0058] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0059] The ion exchange capacity of the prepared anion exchange fiber containing amine groups was 2.62 mmol / g.

[0060] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 1D and a length of 3mm and Tencel fiber obtained above are mixed to obtain mixed fiber. The mixed fiber is then dispersed in water to make a slurry. The concentration of mixed fiber in the slurry is 0.01%.

[0061] The mixed fiber is composed of the following raw materials in the following mass percentages: 20% cation exchange fiber containing carboxyl groups, 40% anion exchange fiber containing amine groups, 30% polyolefin fiber, and 10% Tencel fiber.

[0062] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a tunnel oven at 130°C to produce a highly uniform wet-laid nonwoven fabric with a surface density of 20–40 g / m². 2 between.

[0063] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and pressure rollers to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 110℃, and the pressure of the pressure rollers is 2MPa. The areal density of the prepared mask filter material is 20.5~42.0g / m³. 2 Breathability is 3-6m 3 / m·min, with a filtration efficiency of 99.43%.

[0064] Example 3

[0065] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0066] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cotton cellulose fibers.

[0067] The mask filter material is prepared according to the following steps:

[0068] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, spread them evenly in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 40KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 15% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 5 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0069] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0070] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0071] The prepared cation exchange fiber containing carboxyl groups has an ion exchange capacity of 5.28 mmol / g, a fineness of 0.5–1.5D, and a length of 3–6 mm.

[0072] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, evenly spread them in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 40KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 20% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 5 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0073] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0074] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0075] The ion exchange capacity of the prepared anion exchange fiber containing amine groups was 3.11 mmol / g.

[0076] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 1D and a length of 3mm and cotton cellulose fiber obtained above are mixed to obtain mixed fiber. The mixed fiber is then dispersed in water to make a slurry. The concentration of mixed fiber in the slurry is 0.01%.

[0077] The blended fiber is composed of the following raw materials in the following weight percentages: 30% cation exchange fiber containing carboxyl groups, 40% anion exchange fiber containing amine groups, 20% polyolefin fiber, and 10% cotton cellulose fiber.

[0078] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a tunnel oven at 130°C to produce a highly uniform wet-laid nonwoven fabric with a surface density of 20–40 g / m². 2 between.

[0079] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and pressure rollers to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 130℃, and the pressure of the pressure rollers is 5MPa. The areal density of the prepared mask filter material is 20.5~42.0g / m³. 2 Breathability is 3-6m 3 / m·min, with a filtration efficiency of 99.13%.

[0080] Example 4

[0081] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0082] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and viscose fibers.

[0083] The mask filter material is prepared according to the following steps:

[0084] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, spread them evenly in a polyethylene plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 40KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 10% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0085] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0086] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0087] The ion exchange capacity of the prepared carboxyl-containing cation exchange fiber was 2.72 mmol / g.

[0088] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain amount of polyolefin fibers with a fineness of 0.5D and a length of 3mm, spread them evenly in a plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 40KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 15% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0089] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0090] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0091] The ion exchange capacity of the prepared anion exchange fiber containing amine groups was 1.85 mmol / g.

[0092] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 1.5D and a length of 6mm and viscose fiber obtained above are mixed to obtain mixed fibers. The mixed fibers are then dispersed in water to make a slurry. The concentration of mixed fibers in the slurry is 0.01%.

[0093] The mixed fiber is composed of the following raw materials in the following mass percentages: 20% cation exchange fiber containing carboxyl groups, 30% anion exchange fiber containing amine groups, 30% polyolefin fiber, and 20% viscose fiber.

[0094] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a tunnel oven at 130°C to produce a highly uniform wet-laid nonwoven fabric with a surface density of 20–40 g / m². 2 between.

[0095] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and pressure rollers to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 130℃, and the pressure of the pressure rollers is 3MPa. The areal density of the prepared mask filter material is 20.5~42.0g / m³. 2 Breathability is 3-6m 3 / m·min, with a filtration efficiency of 99.27%.

[0096] Example 5

[0097] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0098] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cellulose fibers.

[0099] The mask filter material is prepared according to the following steps:

[0100] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 1.0D and a length of 6mm, spread them evenly in a plastic packaging bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 20KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 13% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 4 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0101] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0102] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0103] The ion exchange capacity of the prepared carboxyl-containing cation exchange fiber was 4.14 mmol / g.

[0104] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain amount of polyolefin fibers with a fineness of 1.0D and a length of 6mm, spread them evenly in a plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 20KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 17% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 4 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0105] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0106] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0107] The prepared anion exchange fiber containing amino groups had an ion exchange capacity of 2.46 mmol / g.

[0108] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 0.5D and a length of 4mm and cellulose fiber obtained above are mixed to obtain mixed fiber. The mixed fiber is then dispersed in water to make a slurry. The concentration of mixed fiber in the slurry is 0.1%.

[0109] The mixed fiber is composed of the following raw materials in the following mass percentages: 25% cation exchange fiber containing carboxyl groups, 35% anion exchange fiber containing amine groups, 10% polyolefin fiber, and 30% cellulose fiber. The cellulose fiber is composed of equal amounts of softwood pulp fiber, viscose fiber, and Tencel fiber.

[0110] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a tunnel oven at 130°C to produce a highly uniform wet-laid nonwoven fabric with a surface density of 20–40 g / m². 2 between.

[0111] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and a pressure roller to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 150℃, and the pressure of the pressure roller is 5MPa. The filtration efficiency of the prepared mask filter material is 99.18%.

[0112] Example 6

[0113] A mask filter material that combines ion adsorption and particulate filtration functions is composed of wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane through thermal bonding.

[0114] The wet-laid nonwoven layer is prepared by wet web forming technology from cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cellulose fibers.

[0115] The mask filter material is prepared according to the following steps:

[0116] S1. Preparation of cation exchange fibers containing carboxyl groups: Weigh a certain amount of polyolefin fibers with a fineness of 1.5D and a length of 4mm, spread them evenly in a plastic packaging bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 60KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 20% (w / w) acrylic acid aqueous solution grafting solution for later use. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0117] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0118] The fibers are removed, washed in deionized water to remove unreacted substances and homopolymers, and then dried to obtain cation exchange fibers containing carboxyl groups.

[0119] The ion exchange capacity of the prepared carboxyl-containing cation exchange fiber was 4.57 mmol / g.

[0120] S2. Preparation of anion exchange fibers containing amine groups: Weigh a certain amount of polyolefin fibers with a fineness of 1.5D and a length of 4mm, evenly spread them in a plastic bag, and place them in the irradiation area of ​​an electron beam accelerator to receive irradiation. The absorbed dose of the electron beam irradiation is 60KGy. After irradiation, load the fibers into a glass reactor for later use. Prepare a 20% (w / w) dimethylaminoacrylate aqueous solution for grafting. Connect the glass reactor to a vacuum device, evacuate, and draw in the grafting solution to immerse the fibers. Stop the liquid feeding. The amount of grafting solution used is 3 times the weight of the fibers. Further evacuate to deoxygenate, then close all valves and remove the connections. Place the glass reactor in a 60℃ constant temperature water bath and heat for 6 hours.

[0121] After the reaction is complete, the glass reactor is removed and cooled to room temperature.

[0122] The fibers are removed, placed in deionized water for boiling and washing to remove unreacted substances and homopolymers, and then dried to obtain anion exchange fibers containing amine groups.

[0123] The prepared anion exchange fiber containing amine groups had an ion exchange capacity of 2.27 mmol / g.

[0124] S3. The carboxyl-containing cation exchange fiber, amine-containing anion exchange fiber, polyolefin fiber with a fineness of 0.5D and a length of 6mm and cellulose fiber obtained above are mixed to obtain mixed fiber. The mixed fiber is then dispersed in water to make a slurry. The concentration of mixed fiber in the slurry is 0.05%.

[0125] The mixed fiber is composed of the following raw materials in the following mass percentages: 20% cation exchange fiber containing carboxyl groups, 40% anion exchange fiber containing amine groups, 10% polyolefin fiber, and 30% cellulose fiber, wherein the cellulose fiber is composed of equal amounts of softwood pulp fiber and Tencel fiber.

[0126] S4. The above slurry is transported through a pipeline to a wet-laid inclined wire forming machine. Through filtration and deposition, a wet fiber membrane is formed. This membrane is then further dried and shaped in a hot cylinder at 130°C to produce a highly uniform wet-laid nonwoven fabric with an areal density of 20–40 g / m². 2 between.

[0127] S5. The above-mentioned wet-laid nonwoven fabric is laminated with a polytetrafluoroethylene nanoporous membrane, and then laminated together using a thermal bonding machine equipped with a felt pressing belt and a pressure roller to prepare a mask filter material with both ion adsorption and particulate filtration functions. The thermal bonding temperature is 130℃, and the pressure of the pressure roller is 4MPa. The filtration efficiency of the prepared mask filter material is 99.13%.

[0128] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, preferred embodiments are described in this invention to avoid redundancy.

[0129] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0130] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a mask filter material with both ion adsorption and particulate filtration functions, characterized in that, Prepare according to the following steps: S1. A mixture of cation exchange fibers containing carboxyl groups, anion exchange fibers containing amine groups, polyolefin fibers, and cellulose fibers is obtained. The mixture fibers are then dispersed in water to form a slurry. The mass concentration of the mixed fibers in the slurry is 0.01-0.1%; the mixed fibers are composed of the following raw materials in mass percentage: 20-30% cation exchange fibers containing carboxyl groups, 30-40% anion exchange fibers containing amine groups, 10-30% polyolefin fibers, and the remainder is cellulose fibers; The cation exchange fiber containing carboxyl groups is obtained by radiation grafting modification using polyolefin fiber as the base material and acrylic acid aqueous solution as the grafting liquid. The conditions for preparing cation exchange fibers containing carboxyl groups by radiation grafting modification are as follows: the absorbed dose of electron beam irradiation is 20-60 KGy; the mass percentage of the acrylic acid aqueous solution is 10-15%; and the amount of acrylic acid aqueous solution is 3-5 times the mass of the polyolefin fiber. The cation exchange fibers containing carboxyl groups have a fineness of 0.5~1.5D and a length of 3~6mm; Anion exchange fibers containing amine groups are obtained by radiation grafting modification using polyolefin fibers as the base material and dimethylaminoacrylate aqueous solution as the grafting liquid. The conditions for preparing anion exchange fibers containing amine groups by radiation grafting modification are as follows: the absorbed dose of electron beam irradiation is 20~60KGy; the mass percentage of the dimethylaminoacrylate aqueous solution is 15~20%; and the amount of dimethylaminoacrylate aqueous solution is 3~5 times the mass of the polyolefin fiber. The anion exchange fibers containing amine groups have a fineness of 0.5~1.5D and a length of 3~6mm; S2. The slurry is fed into a wet-laid inclined wire forming machine, where it is filtered and deposited to form a wet fiber membrane. The membrane is then dried and shaped to produce a highly uniform wet-laid nonwoven fabric. S3. A mask filter material with both ion adsorption and particulate filtration is prepared by thermally bonding wet nonwoven fabric with polytetrafluoroethylene nanoporous membrane.

2. The method for preparing the mask filter material with both ion adsorption and particulate filtration functions according to claim 1, characterized in that, The polyolefin fiber is a core-sheath composite fiber made of polyethylene and polypropylene, with the core layer being polypropylene. Its outer layer is made of polyethylene; the fineness of the polyolefin fibers is 0.5~1.5D and the length is 3~6mm.

3. The method for preparing the mask filter material with both ion adsorption and particulate filtration functions according to claim 1, characterized in that, Cellulose fibers are one or more of the following: coniferous wood pulp fiber, cotton cellulose fiber, viscose fiber, and Tencel fiber.

4. The method for preparing the mask filter material with both ion adsorption and particulate filtration functions according to claim 1, characterized in that, In S2, the drying method is tunnel drying oven or hot cylinder drying and shaping; the areal density of wet-laid nonwoven fabric is 20~40g / m². 2 .

5. The method for preparing the mask filter material with both ion adsorption and particulate filtration functions according to claim 1, characterized in that, In S3, the polytetrafluoroethylene nanoporous membrane has a nanoscale microporous structure with an areal density of 0.5~2.0 g / m³. 2 Breathability is 3~6m 3 / m·min; Wet-laid nonwoven fabric and polytetrafluoroethylene nanoporous membrane are laminated together and thermally bonded using a thermal laminating machine equipped with felt pressure belts and pressure rollers; the thermal bonding temperature is 110-150℃ and the pressure of the pressure rollers is 2-5MPa.

6. A mask filter material with both ion adsorption and particulate filtration functions prepared by the preparation method according to any one of claims 1 to 5.