Natural plant-based antibacterial sanitary towel surface layer material and sanitary towel

Abstract

The invention discloses a natural plant-based antibacterial sanitary towel surface layer material and a sanitary towel, and relates to the field of fabrics. When the natural plant-based antibacterial sanitary towel surface layer material is prepared, firstly, bamboo pulp fibers pretreated by 3-chloropropyltriethoxysilane react with benzimidazole-1-acetic acid, and then modified bamboo pulp fibers are obtained through amidation and sodium hypobromite degradation; the preparation method comprises the following steps: firstly, preparing bamboo pulp fibers, secondly, initiating acrylamide and N-isopropylacrylamide to be polymerized by a China hemp fiber grafting initiator to obtain modified China hemp fibers, and finally, performing blowing, carding, lapping, spunlacing, degreasing, bleaching and finishing agent after-finishing on the modified bamboo pulp fibers and the modified China hemp fibers to obtain the natural plant-based antibacterial sanitary towel surface layer material. The natural plant-based antibacterial sanitary napkin surface layer material prepared by the invention has excellent antibacterial property and anti-back permeation property.

Description

Technical Field

[0001] The invention relates to the technical field of fabrics, in particular to a natural plant-based antibacterial sanitary napkin surface material and a sanitary napkin. Background Art

[0002] Sanitary napkins are personal hygiene products used by women during menstruation. They are usually made of multiple layers of materials. Common structures include a surface layer, an absorption layer, a diversion layer, and a bottom layer to ensure effective absorption and locking of menstrual blood while keeping the skin dry and comfortable. The surface layer, as the part of the sanitary napkin that comes in direct contact with the skin, is very important in terms of material selection. It not only needs to be skin-friendly and breathable, but also has certain hygroscopicity and antibacterial properties to reduce bacterial growth and maintain the health of private parts.

[0003] The surface materials of traditional sanitary napkins are mostly chemical fiber non-woven fabrics or cotton materials. Although these materials have certain performance in moisture absorption and breathability, they are insufficient in antibacterial performance. In recent years, with the increasing awareness of consumers on health and environmental protection, natural plant-based fibers such as bamboo pulp fiber and hemp fiber have gradually become the preferred surface materials. Bamboo pulp fiber, with its excellent moisture absorption and breathability, as well as natural antibacterial and antibacterial properties, can effectively reduce bacterial growth and keep private parts clean. Hemp fiber has moisture absorption, breathability, comfort, mildew resistance and antibacterial properties, and is regarded as the most promising green fiber in the 21st century, the second layer of human skin.

[0004] Therefore, in order to meet the market demand for healthier and more environmentally friendly sanitary napkins, it is particularly important to develop a sanitary napkin surface material with natural plant-based fibers, such as bamboo pulp fibers or hemp fibers, that has both antibacterial and reverse osmosis functions. This new surface material can not only significantly improve the comfort and health of sanitary napkins, but also effectively reduce the risk of infection in private parts, providing women with a more secure and healthy menstrual care experience. Summary of the invention

[0005] The purpose of the present invention is to provide a natural plant-based antibacterial sanitary napkin surface material to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A natural plant-based antibacterial sanitary napkin surface material is prepared by cleaning, combing, web laying, spunlacing, degreasing, bleaching and finishing with a finishing agent of modified bamboo pulp fiber and modified hemp fiber.

[0008] As an optimization, the modified bamboo pulp fiber is obtained by reacting the pretreated bamboo pulp fiber with benzimidazole-1-acetic acid, and then undergoing amidation and sodium hypobromite degradation.

[0009] As an optimization, the modified hemp fiber is obtained by polymerizing acrylamide and N-isopropylacrylamide initiated by a hemp fiber grafting initiator.

[0010] As an optimization, the finishing agent comprises sodium alginate and benzimidazole quaternary ammonium salt.

[0011] A method for preparing a natural plant-based antibacterial sanitary napkin surface material, comprising the following preparation steps:

[0012] (1) Pretreated bamboo pulp fiber, benzimidazole-1-acetic acid, potassium iodide, and acetonitrile are mixed in a mass ratio of 1: (0.5-0.7): (0.2-0.3): (20-30), heated to 90-95° C., reacted for 6-8 hours, filtered, washed with pure water for 3-4 times, and vacuum dried at 60° C. to obtain pre-modified bamboo pulp fiber;

[0013] (2) Pre-modified bamboo pulp fiber, dichlorothionyl and N,N-dimethylformamide are mixed in a mass ratio of 1:(10-12):(0.1-0.2), heated to 75-80°C and refluxed for reaction for 30-40 minutes, filtered after the reaction, and dichloromethane (10-12 times the mass of the pre-modified bamboo pulp fiber) and 25wt% ammonia water saturated with ammonium carbonate (2-3 times the mass of the pre-modified bamboo pulp fiber) are added, reacted at room temperature for 20-30 minutes, filtered and washed with pure water for 3-4 times, and vacuum dried at 60°C to obtain amidated bamboo pulp fiber; at -5-0°C, amidated bamboo pulp fiber, sodium hypobromite solution and 4 mol / L sodium hydroxide solution are mixed in a mass ratio of 1:(5-7):(0.6-0.7) and ultrasonicated for 10 minutes, then heated to 75-80°C, reacted for 1 hour, filtered and washed with pure water for 3-4 times, and vacuum dried at 60°C to obtain modified bamboo pulp fiber;

[0014] (3) Weigh bromoisobutyryl bromide and pyridine in a molar ratio of 1:1, mix bromoisobutyryl bromide, pyridine, and dichloromethane with a mass of 10-12 times that of pyridine, add hemp fiber with a mass of 2-3 times that of pyridine, react at room temperature for 4 hours, filter and wash 4 times with ethanol to obtain pretreated hemp fiber; mix the pretreated hemp fiber, N,N-dimethylformamide, cuprous bromide, pentamethyldiethylenetriamine, acrylamide, and N-isopropylacrylamide in a mass ratio of 1:(20-30):(0.1-0.2):(0.01-0.02):(0.2-0.3):(0.2-0.3), react at 60°C for 4 hours, filter and wash 4 times with ethanol, and vacuum dry at 60°C to obtain modified hemp fiber;

[0015] (4) opening and combing the modified bamboo pulp fiber and the modified hemp fiber respectively, and laying the modified bamboo pulp fiber and the modified hemp fiber on a net at a mass ratio of 1:(0.8-1.2), so that the modified bamboo pulp fiber is on the lower layer and the modified hemp fiber is on the upper layer, and the surface density is 40-60g / m 2 , the fabric is subjected to hydroentanglement reinforcement treatment in a hydroentanglement machine, the hydroentanglement pressure of the hydroentanglement machine is 40-50MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey fabric is obtained by degreasing and bleaching;

[0016] (5) At 70-80° C., formaldehyded sodium alginate, benzimidazole quaternary ammonium salt and pure water are mixed in a mass ratio of 1:(2-3):(20-30) to obtain a finishing agent solution, and the solution is added to the grey cloth, wherein the mass ratio of the grey cloth to the finishing solution is 1:(20-30). After immersion for 20-30 minutes, the solution is immersed and rolled at a immersion and rolling temperature of 60-70° C. and a rolling rate of 100%-120%. The solution is pre-dried at 60-70° C. for 2-3 minutes, and dried at room temperature to obtain a natural plant-based antibacterial sanitary napkin surface material.

[0017] As an optimization, the preparation method of the pretreated bamboo pulp fiber in step (1) is: mix the bamboo pulp fiber and 2wt% 3-chloropropyltriethoxysilane-ethanol solution in a mass ratio of 1:30, stir at 25°C for 1h, filter and wash with pure water, and vacuum dry at 60°C to obtain the pretreated bamboo pulp fiber; the bamboo pulp fiber is wormwood-modified bamboo pulp fiber, and the specification is 1.33dtex×38mm.

[0018] As an optimization, the sodium hypobromite solution in step (2) is obtained by mixing bromine and 4 mol / L sodium hydroxide in a volume ratio of 1:15.

[0019] As an optimization, the hemp fiber in step (3) is fully degummed hemp fiber.

[0020] As an optimization, the preparation method of the imidazole quaternary ammonium salt in step (5) is as follows: methyl (2-methyl-1H-benzimidazole-1-yl) acetate and methyl iodide are weighed in a molar ratio of 1:1, methyl (2-methyl-1H-benzimidazole-1-yl) acetate, methyl iodide, and acetonitrile with a mass of 15 times that of methyl iodide are mixed, and refluxed at 85°C for 32 hours. After the reaction is completed, the imidazole quaternary ammonium salt precursor is obtained by vacuum distillation and recrystallization from acetone; the imidazole quaternary ammonium salt precursor, N,N-dimethylformamide, and 1M sodium hydroxide solution ammonia mass ratio of 1:40:40 are mixed, and refluxed at 110°C for 48 hours. After the reaction is completed, pure water is added, and the pH is adjusted to 1 with hydrochloric acid. After filtering and drying, the imidazole quaternary ammonium salt is obtained by recrystallization with ethanol.

[0021] As an optimization, the preparation method of the aldehyde-modified sodium alginate in step (5) is as follows: sodium alginate, pure water, and 10wt% sodium periodate solution are mixed in a mass ratio of 1:1000:10.8, stirred in the dark for 4 hours, and then ethylene glycol in an amount equal to that of the sodium alginate is added, and dialyzed with pure water for three days, and freeze-dried to obtain the aldehyde-modified sodium alginate.

[0022] The present invention also provides a sanitary napkin, the surface layer material of the sanitary napkin is prepared by the preparation method of the natural plant-based antibacterial sanitary napkin surface layer material.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0024] When preparing the natural plant-based antibacterial sanitary napkin surface material, the present invention firstly reacts bamboo pulp fiber pretreated with 3-chloropropyltriethoxysilane with benzimidazole-1-acetic acid, and then undergoes amidation and sodium hypobromite degradation to obtain modified bamboo pulp fiber; secondly, hemp fiber is grafted with an initiator to initiate polymerization of acrylamide and N-isopropylacrylamide to obtain modified hemp fiber; finally, the modified bamboo pulp fiber and the modified hemp fiber are subjected to cleaning, combing, web laying, hydroentanglement, degreasing, bleaching, and finishing with a finishing agent to obtain the natural plant-based antibacterial sanitary napkin surface material.

[0025] The fabric of the present invention innovatively adopts a mixed double-layer and double-material combination, with a two-layer structure, that is, the upper layer is made of hemp fiber and the lower layer is made of bamboo pulp fiber structure, which is formed in one step through a spunlace process. This allows consumers to come into contact with the natural hemp fiber layer when using it, achieving an antibacterial and safe experience, and quickly conducts liquid through the lower bamboo pulp fiber layer, reducing the feeling of stuffiness and increasing comfort.

[0026] Firstly, bamboo pulp fibers are pretreated with 3-chloropropyltriethoxysilane to carry chlorine groups on the bamboo pulp fibers, and the chlorine groups react with benzimidazole-1-acetic acid to generate quaternary ammonium salts with antibacterial properties, and then the carboxylic acid groups on the benzimidazole-1-acetic acid are converted into amide groups and then degraded into amino groups through amidation and sodium hypobromite degradation;

[0027] Secondly, the hemp fiber is grafted with an initiator to initiate the polymerization of acrylamide and N-isopropyl acrylamide to obtain modified hemp fiber; hemp fiber has a cavity structure and is connected to many cracks and small holes distributed longitudinally on the fiber surface. Its moisture discharge is three times that of pure cotton. Hemp contains trace amounts of hemp phenols and more than ten trace elements that are beneficial to human health; fibers containing polyacrylamide on the surface can enhance hydrophilicity;

[0028] Finally, the modified bamboo pulp fiber and the modified hemp fiber are subjected to cleaning, combing, web laying, hydroentanglement, degreasing, bleaching, and finishing with a finishing agent to obtain a natural plant-based antibacterial sanitary napkin surface material; the finishing agent is a mixture of formaldehyde sodium alginate and imidazole quaternary ammonium salt, the formaldehyde sodium alginate mainly modifies the surface of the bamboo pulp fiber on the surface layer by Schiff base reaction with the amino groups on the surface of the modified bamboo pulp fiber, the imidazole quaternary ammonium salt contains both positively charged amino groups and positively charged carboxyl groups, and the quaternary ammonium salt structure on the surface of the bamboo pulp fiber on the surface layer also contains both positively charged amino groups and positively charged carboxyl groups, which can form a layer of hydrogel film on the surface layer through self-assembly through the attraction between positive and negative charges, the hydrogel film has good water absorption and swelling properties, can improve the water absorption of the material, and the quaternary ammonium salt structure can further improve the antibacterial property; menstrual blood contains a small amount of calcium ions, and the sodium alginate and polyacrylamide on the surface of the hemp fiber can be cross-linked by calcium ions to form a network, which can not only improve the water absorption of the material, but also prevent the reverse osmosis of menstrual blood. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] The bamboo pulp fiber used in the following examples and comparative examples is wormwood modified bamboo pulp fiber with a specification of 1.33 dtex×38 mm; the hemp fiber used is fully degummed hemp fiber; the sodium hypobromite solution used is obtained by mixing bromine and 4 mol / L sodium hydroxide in a volume ratio of 1:15.

[0031] Embodiment 1:

[0032] A method for preparing a natural plant-based antibacterial sanitary napkin surface material, the method comprising the following preparation steps:

[0033] (1) Mixing bamboo pulp fiber and 2 wt% 3-chloropropyltriethoxysilane-ethanol solution in a mass ratio of 1:30, stirring at 25°C for 1 hour, filtering and washing with pure water, and vacuum drying at 60°C to obtain pretreated bamboo pulp fiber; mixing pretreated bamboo pulp fiber, benzimidazole-1-acetic acid, potassium iodide, and acetonitrile in a mass ratio of 1:0.5:0.2:20, heating to 95°C, reacting for 8 hours, filtering and washing with pure water for 4 times, and vacuum drying at 60°C to obtain pre-modified bamboo pulp fiber;

[0034] (2) Pre-modified bamboo pulp fiber, dichlorothionyl and N,N-dimethylformamide were mixed in a mass ratio of 1:10:0.1, heated to 80°C and refluxed for 40 minutes, filtered after the reaction, and dichloromethane 10 times the mass of the pre-modified bamboo pulp fiber and 25wt% ammonia water saturated with ammonium carbonate were added in a mass of 2 times the mass of the pre-modified bamboo pulp fiber, reacted at room temperature for 30 minutes, filtered and washed with pure water for 3 times, and vacuum dried at 60°C to obtain amidated bamboo pulp fiber; at 0°C, amidated bamboo pulp fiber, sodium hypobromite solution and 4 mol / L sodium hydroxide solution were mixed in a mass ratio of 1:5:0.6 and ultrasonicated for 10 minutes, then heated to 80°C, reacted for 1 hour, filtered and washed with pure water for 3 times, and vacuum dried at 60°C to obtain modified bamboo pulp fiber;

[0035] (3) Weigh bromoisobutyryl bromide and pyridine in a molar ratio of 1:1, mix bromoisobutyryl bromide, pyridine, and dichloromethane with a mass of 10 times that of pyridine, add hemp fiber with a mass of 2 times that of pyridine, react at room temperature for 4 hours, filter and wash 4 times with ethanol to obtain pretreated hemp fiber; mix the pretreated hemp fiber, N,N-dimethylformamide, cuprous bromide, pentamethyldiethylenetriamine, acrylamide, and N-isopropylacrylamide in a mass ratio of 1:20:0.1:0.01:0.2:0.2, react at 60°C for 4 hours, filter and wash 4 times with ethanol, and vacuum dry at 60°C to obtain modified hemp fiber;

[0036] (4) The modified bamboo pulp fiber and the modified hemp fiber are loosened and combed respectively, and the modified bamboo pulp fiber and the modified hemp fiber are laid on a net at a mass ratio of 1:0.8, so that the modified bamboo pulp fiber is on the lower layer and the modified hemp fiber is on the upper layer, and the surface density is 40 g / m 2 , the fabric is subjected to hydroentanglement reinforcement treatment in a hydroentanglement machine, the hydroentanglement pressure of the hydroentanglement machine is 50MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey fabric is obtained by degreasing and bleaching;

[0037] (5) Methyl (2-methyl-1H-benzimidazol-1-yl) acetate and methyl iodide were weighed in a molar ratio of 1:1, methyl (2-methyl-1H-benzimidazol-1-yl) acetate, methyl iodide, and acetonitrile with a mass of 15 times that of methyl iodide were mixed, and refluxed at 85° C. for 32 hours. After the reaction, the mixture was distilled under reduced pressure and recrystallized from acetone to obtain an imidazole quaternary ammonium salt precursor; an imidazole quaternary ammonium salt precursor, N,N-dimethylformamide, and 1M sodium hydroxide solution ammonia were mixed in a mass ratio of 1:40:40, and refluxed at 110° C. for 48 hours. After the reaction, pure water was added, and the pH was adjusted to 1 with hydrochloric acid. After filtering and drying, the mixture was recrystallized from ethanol to obtain an imidazole quaternary ammonium salt; Sodium alginate, pure water and 10wt% sodium periodate solution are mixed in a mass ratio of 1:1000:10.8, stirred in a dark place for 4 hours, and then ethylene glycol of the same mass as the sodium alginate is added, and dialyzed with pure water for three days, and freeze-dried to obtain aldehyded sodium alginate; at 80°C, aldehyded sodium alginate, benzimidazole quaternary ammonium salt and pure water are mixed in a mass ratio of 1:2:20 to obtain a finishing agent solution, and added to the grey cloth, wherein the mass ratio of the grey cloth to the finishing solution is 1:20, after immersion for 30 minutes, it is immersed and rolled, the immersion and rolling temperature is 70°C, the rolling rate is 120%, pre-baked at 70°C for 3 minutes, and dried at room temperature to obtain a natural plant-based antibacterial sanitary napkin surface material.

[0038] Embodiment 2:

[0039] A method for preparing a natural plant-based antibacterial sanitary napkin surface material, the method comprising the following preparation steps:

[0040] (1) Mixing bamboo pulp fiber and 2 wt% 3-chloropropyltriethoxysilane-ethanol solution in a mass ratio of 1:30, stirring at 25°C for 1 hour, filtering and washing with pure water, and vacuum drying at 60°C to obtain pretreated bamboo pulp fiber; mixing pretreated bamboo pulp fiber, benzimidazole-1-acetic acid, potassium iodide, and acetonitrile in a mass ratio of 1:0.6:0.25:25, heating to 93°C, reacting for 7 hours, filtering and washing with pure water for 3 times, and vacuum drying at 60°C to obtain pre-modified bamboo pulp fiber;

[0041] (2) Pre-modified bamboo pulp fiber, dichlorothionyl, and N,N-dimethylformamide were mixed in a mass ratio of 1:11:0.15, heated to 76°C and refluxed for 35 minutes, filtered after the reaction, and dichloromethane 11 times the mass of the pre-modified bamboo pulp fiber and 25wt% ammonia saturated with ammonium carbonate 2.5 times the mass of the pre-modified bamboo pulp fiber were added, reacted at room temperature for 25 minutes, filtered and washed with pure water three times, and vacuum dried at 60°C to obtain amidated bamboo pulp fiber; at -4°C, amidated bamboo pulp fiber, sodium hypobromite solution, and 4 mol / L sodium hydroxide solution were mixed in a mass ratio of 1:6:0.65 and ultrasonicated for 10 minutes, then heated to 76°C, reacted for 1 hour, filtered and washed with pure water three times, and vacuum dried at 60°C to obtain modified bamboo pulp fiber;

[0042] (3) Weigh bromoisobutyryl bromide and pyridine in a molar ratio of 1:1, mix bromoisobutyryl bromide, pyridine, and dichloromethane 11 times the mass of pyridine, add hemp fiber 2.5 times the mass of pyridine, react at room temperature for 4 hours, filter and wash 4 times with ethanol to obtain pretreated hemp fiber; mix the pretreated hemp fiber, N,N-dimethylformamide, cuprous bromide, pentamethyldiethylenetriamine, acrylamide, and N-isopropylacrylamide in a mass ratio of 1:25:0.15:0.015:0.25:0.26, react at 60°C for 4 hours, filter and wash 4 times with ethanol, and vacuum dry at 60°C to obtain modified hemp fiber;

[0043] (4) The modified bamboo pulp fiber and the modified hemp fiber are loosened and combed respectively, and the modified bamboo pulp fiber and the modified hemp fiber are laid on a net at a mass ratio of 1:1, so that the modified bamboo pulp fiber is on the lower layer and the modified hemp fiber is on the upper layer, and the surface density is 50 g / m 2 , the fabric is subjected to hydroentanglement reinforcement treatment in a hydroentanglement machine, the hydroentanglement pressure of the hydroentanglement machine is 45MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey fabric is obtained by degreasing and bleaching;

[0044] (5) Methyl (2-methyl-1H-benzimidazol-1-yl) acetate and methyl iodide were weighed in a molar ratio of 1:1, methyl (2-methyl-1H-benzimidazol-1-yl) acetate, methyl iodide, and acetonitrile (15 times the mass of methyl iodide) were mixed, and refluxed at 85° C. for 32 hours. After the reaction, the mixture was distilled under reduced pressure and recrystallized from acetone to obtain an imidazole quaternary ammonium salt precursor; an imidazole quaternary ammonium salt precursor, N,N-dimethylformamide, and 1M sodium hydroxide solution (ammonia) were mixed in a mass ratio of 1:40:40, and refluxed at 110° C. for 48 hours. After the reaction, pure water was added, and the pH was adjusted to 1 with hydrochloric acid. After filtering and drying, the mixture was recrystallized from ethanol to obtain an imidazole quaternary ammonium salt; Sodium alginate, pure water and 10wt% sodium periodate solution are mixed in a mass ratio of 1:1000:10.8, stirred in a dark place for 4 hours, and then ethylene glycol of the same mass as the sodium alginate is added, and dialyzed with pure water for three days, and freeze-dried to obtain aldehyded sodium alginate; at 75°C, aldehyded sodium alginate, benzimidazole quaternary ammonium salt and pure water are mixed in a mass ratio of 1:2.5:25 to obtain a finishing agent solution, and the solution is added to the grey cloth, wherein the mass ratio of the grey cloth to the finishing solution is 1:25, and after immersion for 25 minutes, the solution is immersed and rolled, the immersion and rolling temperature is 65°C, the rolling rate is 110%, and the solution is pre-dried at 65°C for 2.5 minutes, and dried at room temperature to obtain a natural plant-based antibacterial sanitary napkin surface material.

[0045] Embodiment 3:

[0046] A method for preparing a natural plant-based antibacterial sanitary napkin surface material, the method comprising the following preparation steps:

[0047] (1) Mixing bamboo pulp fiber and 2 wt% 3-chloropropyltriethoxysilane-ethanol solution in a mass ratio of 1:30, stirring at 25°C for 1 hour, filtering and washing with pure water, and vacuum drying at 60°C to obtain pretreated bamboo pulp fiber; mixing pretreated bamboo pulp fiber, benzimidazole-1-acetic acid, potassium iodide, and acetonitrile in a mass ratio of 1:0.7:0.3:30, heating to 90°C, reacting for 6 hours, filtering and washing with pure water for 3 times, and vacuum drying at 60°C to obtain pre-modified bamboo pulp fiber;

[0048] (2) Pre-modified bamboo pulp fiber, dichlorothionyl, and N,N-dimethylformamide were mixed in a mass ratio of 1:12:0.2, heated to 75°C and refluxed for 30 minutes, filtered after the reaction, and dichloromethane 12 times the mass of the pre-modified bamboo pulp fiber and 25wt% ammonia water saturated with ammonium carbonate 3 times the mass of the pre-modified bamboo pulp fiber were added, reacted at room temperature for 20 minutes, filtered and washed with pure water 3 times, and vacuum dried at 60°C to obtain amidated bamboo pulp fiber; at -5°C, amidated bamboo pulp fiber, sodium hypobromite solution, and 4 mol / L sodium hydroxide solution were mixed in a mass ratio of 1:7:0.7 and ultrasonicated for 10 minutes, then heated to 75°C, reacted for 1 hour, filtered and washed with pure water 3 times, and vacuum dried at 60°C to obtain modified bamboo pulp fiber;

[0049] (3) Weigh bromoisobutyryl bromide and pyridine in a molar ratio of 1:1, mix bromoisobutyryl bromide, pyridine, and dichloromethane 12 times the mass of pyridine, add hemp fiber 3 times the mass of pyridine, react at room temperature for 4 hours, filter and wash 4 times with ethanol to obtain pretreated hemp fiber; mix the pretreated hemp fiber, N,N-dimethylformamide, cuprous bromide, pentamethyldiethylenetriamine, acrylamide, and N-isopropylacrylamide in a mass ratio of 1:30:0.2:0.02:0.3:0.3, react at 60°C for 4 hours, filter and wash 4 times with ethanol, and vacuum dry at 60°C to obtain modified hemp fiber;

[0050] (4) The modified bamboo pulp fiber and the modified hemp fiber are opened and combed respectively, and the modified bamboo pulp fiber and the modified hemp fiber are laid on a net at a mass ratio of 1:1.2, so that the modified bamboo pulp fiber is on the lower layer and the modified hemp fiber is on the upper layer, and the surface density is 60g / m 2 , the fabric is subjected to hydroentanglement reinforcement treatment in a hydroentanglement machine, the hydroentanglement pressure of the hydroentanglement machine is 40MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey fabric is obtained by degreasing and bleaching;

[0051] (5) Methyl (2-methyl-1H-benzimidazol-1-yl) acetate and methyl iodide were weighed in a molar ratio of 1:1, methyl (2-methyl-1H-benzimidazol-1-yl) acetate, methyl iodide, and acetonitrile with a mass of 15 times that of methyl iodide were mixed, and refluxed at 85° C. for 32 hours. After the reaction, the mixture was distilled under reduced pressure and recrystallized from acetone to obtain an imidazole quaternary ammonium salt precursor; an imidazole quaternary ammonium salt precursor, N,N-dimethylformamide, and 1M sodium hydroxide solution ammonia were mixed in a mass ratio of 1:40:40, and refluxed at 110° C. for 48 hours. After the reaction, pure water was added, and the pH was adjusted to 1 with hydrochloric acid. After filtering and drying, the mixture was recrystallized from ethanol to obtain an imidazole quaternary ammonium salt; Sodium alginate, pure water and 10wt% sodium periodate solution are mixed in a mass ratio of 1:1000:10.8, stirred in a dark place for 4 hours, and then ethylene glycol of the same mass as the sodium alginate is added, and dialyzed with pure water for three days, and freeze-dried to obtain aldehyded sodium alginate; at 70°C, aldehyded sodium alginate, benzimidazole quaternary ammonium salt and pure water are mixed in a mass ratio of 1:3:30 to obtain a finishing agent solution, and added to the grey cloth, wherein the mass ratio of the grey cloth to the finishing liquid is 1:30, after immersion for 20 minutes, it is immersed and rolled, the immersion and rolling temperature is 60°C, the rolling rate is 100%, pre-baked at 60°C for 2 minutes, and dried at room temperature to obtain a natural plant-based antibacterial sanitary napkin surface material.

[0052] Comparative Example 1:

[0053] The preparation method of the natural plant-based antibacterial sanitary napkin surface material of Comparative Example 1 is different from that of Example 2 in that it does not contain steps (1) to (2) and (5), and step (4) is modified as follows: the bamboo pulp fiber and the modified hemp fiber are loosened and combed, and the bamboo pulp fiber and the modified hemp fiber are laid on a net at a mass ratio of 1:1, so that the modified bamboo pulp fiber is in the lower layer and the modified hemp fiber is in the upper layer, and the surface density is 50g / m 2 , and hydroentanglement reinforcement treatment is carried out in a hydroentanglement machine. The hydroentanglement pressure of the hydroentanglement machine is 45MPa, the mesh curtain speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then degreasing and bleaching are carried out to obtain the natural plant-based antibacterial sanitary napkin surface material.

[0054] Comparative Example 2:

[0055] The preparation method of the natural plant-based antibacterial sanitary napkin surface material of Comparative Example 2 differs from that of Example 2 in that step (3) is not included, and step (4) is modified as follows: the modified bamboo pulp fiber and the hemp fiber are loosened and combed, and the modified bamboo pulp fiber and the hemp fiber are laid on a net at a mass ratio of 1:1, so that the modified bamboo pulp fiber is in the lower layer and the modified hemp fiber is in the upper layer, and the surface density is 50 g / m 2The water spunlace reinforcement treatment is carried out in a water spunlace machine. The water spunlace pressure of the water spunlace machine is 45MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey cloth is obtained by degreasing and bleaching.

[0056] Test Example 1:

[0057] Absorption performance test:

[0058] Test method: The back permeation of the examples and comparative examples was tested with reference to the standard GB / T30133-2013, the test solution used in the experiment was replaced with anticoagulated pig blood, the examples and comparative examples were cut into samples with a size of 100 mm × 100 mm, each sample was tested 5 times, and the average value was taken. The results are shown in Table 1.

[0059] Table 1

[0060] Re-seepage amount (g) Re-seepage amount (g) Example 1 0.5763 Comparative Example 1 1.4863 Example 2 0.5642 Comparative Example 2 1.0633 Example 3 0.5621

[0061] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 2 in Table 1, it can be found that the antibacterial sanitary napkin surface layer material prepared by the present invention has good anti-reseepage performance.

[0062] By comparison, the back-seepage amount of Examples 1 to 3 is less than that of Comparative Examples 1 to 2, indicating that the modified bamboo pulp fiber and the modified hemp fiber are subjected to cleaning, combing, web laying, spunlace, degreasing, bleaching, and finishing with a finishing agent to obtain a natural plant-based antibacterial sanitary napkin surface material; the finishing agent is a mixture of aldehyded sodium alginate and imidazole quaternary ammonium salt, the aldehyded sodium alginate reacts with the amino groups on the surface of the modified bamboo pulp fiber to mainly modify the surface of the bamboo pulp fiber on the surface layer, and the imidazole quaternary ammonium salt contains both positively charged amino groups and The quaternary ammonium salt structure on the surface of the bamboo pulp fiber layer also contains positively charged amino groups and positively charged carboxyl groups, which can form a hydrogel film on the surface layer through self-assembly through the attraction between positive and negative charges. The hydrogel film has good water absorption and swelling properties, which can improve the water absorption of the material; menstrual blood contains a small amount of calcium ions, and sodium alginate and polyacrylamide on the surface of hemp fiber can be cross-linked through calcium ions to form a network, which can not only improve the water absorption of the material, but also prevent the reverse osmosis of menstrual blood.

[0063] Test Example 2:

[0064] Antibacterial performance test:

[0065] Test method: The antibacterial properties of the sanitary napkin fabrics prepared in the examples and comparative examples were tested according to the reference standard GB / T20944.2. The results are shown in Table 2.

[0066] Table 2

[0067] Antibacterial rate (%) Antibacterial rate (%) Example 1 99.74 Comparative Example 1 92.31 Example 2 99.81 Comparative Example 2 99.63 Example 3 99.89

[0068] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 2 in Table 2, it can be found that the antibacterial sanitary napkin surface layer material prepared by the present invention has good antibacterial properties.

[0069] By comparison, the antibacterial rates of Examples 1 to 3 are greater than that of Comparative Example 1, indicating that the bamboo pulp fibers pretreated with 3-chloropropyltriethoxysilane carry chlorine groups on the bamboo pulp fibers, and the chlorine groups react with benzimidazole-1-acetic acid to generate quaternary ammonium salts with antibacterial properties. The modified bamboo pulp fibers and modified hemp fibers are subjected to cleaning, combing, web laying, hydroentanglement, degreasing, bleaching, and finishing with a finishing agent to obtain a natural plant-based antibacterial sanitary napkin surface material; the finishing agent is a mixture of formaldehyde-modified sodium alginate and imidazole quaternary ammonium salt, and the formaldehyde-modified sodium alginate The surface of the bamboo pulp fiber is mainly modified by Schiff base reaction with the amino groups on the surface of the modified bamboo pulp fiber. The imidazole quaternary ammonium salt contains both positively charged amino groups and positively charged carboxyl groups. The quaternary ammonium salt structure on the surface of the bamboo pulp fiber also contains both positively charged amino groups and positively charged carboxyl groups. It can form a layer of hydrogel film on the surface layer through self-assembly through the attraction between positive and negative charges. The hydrogel film has good water absorption and swelling properties, which can improve the water absorption of the material. The quaternary ammonium salt structure can further improve the antibacterial properties.

[0070] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A natural plant-based antibacterial sanitary napkin surface material, characterized in that: The natural plant-based antibacterial sanitary napkin surface material is made from modified bamboo pulp fiber and modified hemp fiber through cleaning, combing, web laying, spunlace, degreasing, bleaching, and finishing with a finishing agent; The modified bamboo pulp fiber is obtained by reacting pretreated bamboo pulp fiber with benzimidazole-1-acetic acid, and then undergoing amidation and sodium hypobromite degradation; The modified hemp fiber is obtained by polymerization of acrylamide and N-isopropyl acrylamide initiated by a hemp fiber grafting initiator; The finishing agent comprises sodium alginate and benzimidazole quaternary ammonium salt.

2. A method for preparing the natural plant-based antibacterial sanitary napkin surface material according to claim 1, characterized in that: The method comprises the following preparation steps: (1) Pretreated bamboo pulp fiber, benzimidazole-1-acetic acid, potassium iodide, and acetonitrile are mixed in a mass ratio of 1: (0.5-0.7): (0.2-0.3): (20-30), heated to 90-95° C., reacted for 6-8 hours, filtered, washed with pure water for 3-4 times, and vacuum dried at 60° C. to obtain pre-modified bamboo pulp fiber; (2) Pre-modified bamboo pulp fiber, dichlorothionyl and N,N-dimethylformamide are mixed in a mass ratio of 1:(10-12):(0.1-0.2), heated to 75-80°C and refluxed for reaction for 30-40 minutes, filtered after the reaction, and dichloromethane (10-12 times the mass of the pre-modified bamboo pulp fiber) and 25wt% ammonia water saturated with ammonium carbonate (2-3 times the mass of the pre-modified bamboo pulp fiber) are added, reacted at room temperature for 20-30 minutes, filtered and washed with pure water for 3-4 times, and vacuum dried at 60°C to obtain amidated bamboo pulp fiber; at -5-0°C, amidated bamboo pulp fiber, sodium hypobromite solution and 4 mol / L sodium hydroxide solution are mixed in a mass ratio of 1:(5-7):(0.6-0.7) and ultrasonicated for 10 minutes, then heated to 75-80°C, reacted for 1 hour, filtered and washed with pure water for 3-4 times, and vacuum dried at 60°C to obtain modified bamboo pulp fiber; (3) Weigh bromoisobutyryl bromide and pyridine in a molar ratio of 1:1, mix bromoisobutyryl bromide, pyridine, and dichloromethane with a mass of 10-12 times that of pyridine, add hemp fiber with a mass of 2-3 times that of pyridine, react at room temperature for 4 hours, filter and wash 4 times with ethanol to obtain pretreated hemp fiber; mix the pretreated hemp fiber, N,N-dimethylformamide, cuprous bromide, pentamethyldiethylenetriamine, acrylamide, and N-isopropylacrylamide in a mass ratio of 1:(20-30):(0.1-0.2):(0.01-0.02):(0.2-0.3):(0.2-0.3), react at 60°C for 4 hours, filter and wash 4 times with ethanol, and vacuum dry at 60°C to obtain modified hemp fiber; (4) opening and combing the modified bamboo pulp fiber and the modified hemp fiber respectively, and laying the modified bamboo pulp fiber and the modified hemp fiber on a net at a mass ratio of 1:(0.8-1.2), so that the modified bamboo pulp fiber is on the lower layer and the modified hemp fiber is on the upper layer, and the surface density is 40-60g / m 2 , the fabric is subjected to hydroentanglement reinforcement treatment in a hydroentanglement machine, the hydroentanglement pressure of the hydroentanglement machine is 40-50MPa, the screen conveying speed is 4m / min, the water needle distance is 14mm, the water spray hole diameter is 0.2mm, and then the grey fabric is obtained by degreasing and bleaching; (5) At 70-80° C., formaldehyded sodium alginate, benzimidazole quaternary ammonium salt and pure water are mixed in a mass ratio of 1:(2-3):(20-30) to obtain a finishing agent solution, and the solution is added to the grey cloth, wherein the mass ratio of the grey cloth to the finishing solution is 1:(20-30). After immersion for 20-30 minutes, the solution is immersed and rolled at a immersion and rolling temperature of 60-70° C. and a rolling rate of 100%-120%. The solution is pre-dried at 60-70° C. for 2-3 minutes, and dried at room temperature to obtain a natural plant-based antibacterial sanitary napkin surface material.

3. The method for preparing a natural plant-based antibacterial sanitary napkin surface material according to claim 2, characterized in that: The preparation method of the pretreated bamboo pulp fiber in step (1) is: mix the bamboo pulp fiber and 2wt% 3-chloropropyltriethoxysilane-ethanol solution in a mass ratio of 1:30, stir at 25°C for 1h, filter and wash with pure water, and vacuum dry at 60°C to obtain the pretreated bamboo pulp fiber; the bamboo pulp fiber is wormwood-modified bamboo pulp fiber with a specification of 1.33dtex×38mm.

4. The method for preparing a natural plant-based antibacterial sanitary napkin surface material according to claim 2, characterized in that: The sodium hypobromite solution in step (2) is obtained by mixing bromine and 4 mol / L sodium hydroxide in a volume ratio of 1:

15.

5. The method for preparing a natural plant-based antibacterial sanitary napkin surface material according to claim 2, characterized in that: The hemp fiber in step (3) is fully degummed hemp fiber.

6. The method for preparing a natural plant-based antibacterial sanitary napkin surface material according to claim 2, characterized in that: The preparation method of the imidazole quaternary ammonium salt in step (5) is as follows: methyl (2-methyl-1H-benzimidazole-1-yl) acetate and methyl iodide are weighed in a molar ratio of 1:1, methyl (2-methyl-1H-benzimidazole-1-yl) acetate, methyl iodide, and acetonitrile with a mass of 15 times that of methyl iodide are mixed, and refluxed at 85° C. for 32 hours. After the reaction is completed, the imidazole quaternary ammonium salt precursor is obtained by vacuum distillation and recrystallization from acetone; the imidazole quaternary ammonium salt precursor, N,N-dimethylformamide, and 1M sodium hydroxide solution ammonia mass ratio of 1:40:40 are mixed, and refluxed at 110° C. for 48 hours. After the reaction is completed, pure water is added, and the pH is adjusted to 1 using 35wt% hydrochloric acid, and after filtering and drying, the imidazole quaternary ammonium salt is obtained by recrystallization using ethanol.

7. The method for preparing a natural plant-based antibacterial sanitary napkin surface material according to claim 2, characterized in that: The preparation method of the aldehyde-modified sodium alginate in step (5) is as follows: sodium alginate, pure water, and 10wt% sodium periodate solution are mixed in a mass ratio of 1:1000:10.8, stirred for 4 hours in a dark place, and then ethylene glycol in an amount equal to that of the sodium alginate is added, and dialyzed with pure water for three days, and freeze-dried to obtain the aldehyde-modified sodium alginate.

8. A sanitary napkin, characterized in that: The surface layer material of the sanitary napkin is prepared according to the method for preparing the surface layer material of the natural plant-based antibacterial sanitary napkin according to any one of claims 2-7.