A high-absorption and side-leakage-proof 3D liquid sanitary napkin and its preparation method

Abstract

The present invention belongs to the technical field of daily necessities, and specifically relates to a highly absorbent and leak-proof 3D liquid sanitary napkin and a preparation method thereof. A highly absorbent and leak-proof 3D liquid sanitary napkin comprises, from top to bottom, a surface layer, an absorbent layer, and a leak-proof layer; the preparation method of the absorbent layer comprises the following steps: (1) passing a first oil phase, an aqueous phase A, and an aqueous phase B into a first continuous emulsification device to obtain a first emulsion; (2) passing a second oil phase, an aqueous phase C, and an aqueous phase D into a second continuous emulsification device to obtain a second emulsion; (3) applying the first emulsion to the upper surface of a non-woven fabric, and applying the second emulsion to the lower surface of the non-woven fabric, and after light and steam treatment, dehydrating and drying to obtain an absorbent layer. The absorbent layer of the liquid sanitary napkin of the present invention has high flow conductivity and strong liquid absorption capacity, thereby improving the absorption and leak-proof capabilities of the liquid sanitary napkin.

Description

Technical Field

[0001] The present invention belongs to the technical field of daily necessities, and in particular relates to a high-absorption and side-leakage-proof 3D liquid sanitary napkin and a preparation method thereof. Background Art

[0002] Liquid sanitary napkins aren't actually "liquid," but rather absorbent materials that can quickly convert to a liquid state, achieving instant dryness. They utilize innovative materials and innovative absorbent core structures to rapidly absorb and lock in liquids, providing a drier, more comfortable experience.

[0003] There are many types of sanitary napkins on the market, but there are very few sanitary napkins for visually impaired women. For people with visual impairments, high-absorbency products can simplify the management process during menstruation, making the whole experience simpler and more direct.

[0004] The core of a liquid sanitary napkin is the absorbent layer, whose performance directly determines the product's absorption rate, water retention, leak-proofing, and comfort. Compared to traditional sanitary napkins, the absorbent layer of existing liquid sanitary napkins has achieved qualitative improvements through innovative polymer materials and optimized structural design. However, existing absorbent layers still cannot meet the needs of those who demand higher liquid absorption capacity from sanitary napkins.

[0005] A Chinese invention patent with publication number CN 116421766 B discloses a method for preparing a liquid sanitary napkin absorbent core. The method employs a specific surfactant compounded with a long-chain acrylate monomer and a cross-linking agent, and employs a HIPE synthesis process and method to prepare an absorbent core with enhanced adsorption properties. This allows the product to have a higher porosity and a dense microporous structure, achieving a 3D fluid storage function that keeps the sanitary napkin surface dry and extends its usability, solving the problems of pressurized blood backseepage and side leakage associated with traditional core materials. Summary of the Invention

[0006] In view of the above problems, the purpose of the present invention is to provide a high-absorbency and side-leakage-proof 3D liquid sanitary napkin and a preparation method thereof.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A highly absorbent and leak-proof 3D liquid sanitary napkin comprises, from top to bottom, a surface layer, an absorbent layer, and a leak-proof layer; a method for preparing the absorbent layer comprises the following steps:

[0009] (1) Mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a first oil phase; mixing an inorganic salt and water to obtain an aqueous phase A; and mixing a peroxide initiator and water to obtain an aqueous phase B; and passing the first oil phase, aqueous phase A, and aqueous phase B into a first continuous emulsification device to obtain a first emulsion;

[0010] (2) mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a second oil phase, mixing an inorganic salt and water to obtain an aqueous phase C, and mixing a peroxide initiator, carboxymethyl cellulose grafted acrylic acid, and water to obtain an aqueous phase D; passing the second oil phase, aqueous phase C, and aqueous phase D into a second continuous emulsification device to obtain a second emulsion;

[0011] (3) The first emulsion is applied to the upper surface of the non-woven fabric, and the second emulsion is applied to the lower surface of the non-woven fabric. After being treated with light and steam, the non-woven fabric is dehydrated and dried to obtain an absorption layer.

[0012] Preferably, the acrylate monomer in steps (1) and (2) comprises isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of (60-65):(35-40); and the weight ratio of the acrylate monomer, the crosslinking agent, the photoinitiator and the surfactant is 80:(1-1.5):(2-2.5):(4-5).

[0013] Preferably, the volume ratio of the first oil phase, aqueous phase A and aqueous phase B and the volume ratio of the second oil phase, aqueous phase C and aqueous phase D are all 1:(30-35):(5-10).

[0014] Preferably, the crosslinking agent comprises ethylene glycol diacrylate, butylene glycol dimethacrylate and trimethylol triacrylate in a weight ratio of 1: (0.2-0.4): (1.5-1.7).

[0015] Preferably, the peroxide initiator is selected from one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0016] Preferably, the photoinitiator is selected from one or more of benzophenone, benzil, thioxanthone, and benzyl ketal.

[0017] Preferably, the preparation method of carboxymethyl cellulose grafted with acrylic acid comprises the following steps:

[0018] (1) Under a nitrogen atmosphere, 10 parts by weight of carboxymethyl cellulose and 200-230 parts by weight of water were mixed, the temperature was raised to 60-65° C., and the mixture was stirred to dissolve to obtain a carboxymethyl cellulose aqueous solution;

[0019] (2) After adjusting 60 parts by weight of methacrylic acid to neutrality, add it to the carboxymethyl cellulose aqueous solution, continue to add 0.06-0.09 parts by weight of N,N-methylenebisacrylamide, stir evenly, add 1 part by weight of sodium persulfate, heat to 45-50°C, keep warm for 3-4 hours, wash, and dry to obtain carboxymethyl cellulose grafted with acrylic acid.

[0020] Preferably, the surfactant comprises Tween-60, Span-80 and alkyl glycoside in a weight ratio of 1:(1.3-1.5):(0.5-0.7).

[0021] Preferably, aqueous phase A and aqueous phase C contain 3 wt % calcium chloride; aqueous phase B and aqueous phase D contain 10-15 wt % peroxide initiator and 3-5 wt % carboxymethyl cellulose grafted with acrylic acid.

[0022] The preparation method of the highly absorbent and leak-proof 3D liquid sanitary napkin comprises embossing the surface layer at high temperature to form a 3D texture, laminating the surface layer, the absorbent layer and the leak-proof layer in sequence from top to bottom, and combining them into a sanitary napkin by hot pressing.

[0023] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0024] 1. The present invention provides a highly absorbent and side-leakage-proof 3D liquid sanitary napkin. The absorbent layer of the liquid sanitary napkin has excellent flow conductivity and liquid absorbency. The sanitary napkin is suitable for use by visually impaired women, but is not limited to ordinary consumers with high absorption requirements.

[0025] 2. In order to simplify the process, the present invention designs the ratio of the raw materials so that the oil phase and water phase components in the first emulsion and the second emulsion are kept consistent as much as possible. The difference is that carboxymethyl cellulose grafted with acrylic acid is added to the second emulsion. This operation can save the cost and time of ingredients, and the raw material storage tank can be reused.

[0026] 3. The first emulsion used in the absorption layer is provided with a synergistic effect by setting the ratio and composition of the acrylate monomer and the crosslinking agent, and under specific surfactant conditions, so that the pores in the upper layer of the absorption layer formed by the first emulsion are more uniform and more conducive to diversion.

[0027] 4. The second emulsion uses a specific surfactant and carboxymethyl cellulose grafted with acrylic acid is added to the aqueous phase D. The carboxymethyl cellulose grafted with acrylic acid can copolymerize with the acrylate monomer to form an interpenetrating network. Simultaneously, the carboxymethyl cellulose grafted with acrylic acid acts as a high-molecular surfactant, synergizing with the surfactant compounded in the present invention to reduce oil-water interfacial tension and promote droplet refinement. The pore size formed in the absorbent layer is smaller, improving the liquid absorption capacity of the liquid sanitary napkin. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of the liquid sanitary napkin of the present invention, in which: 1, surface layer; 2, absorption layer; 201, non-woven fabric of the absorption layer; 202, upper surface layer formed by the first emulsion; 203, lower surface layer formed by the second emulsion; 3, leakage-proof layer. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0030] The raw materials used in the following examples of the present invention are all commercially available commodities:

[0031] Carboxymethyl cellulose, Hunan Yunbang Biotechnology Co., Ltd., product number YB55201.

[0032] Alkyl polyglycoside, Alkyl polyglycoside APG0814, Jinan Minghao Chemical Co., Ltd.

[0033] Example 1

[0034] This embodiment provides a highly absorbent and leak-proof 3D liquid sanitary napkin, which comprises, from top to bottom, a surface layer, an absorbent layer, and a leak-proof layer; a method for preparing the absorbent layer comprises the following steps:

[0035] (1) Mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a first oil phase; mixing an inorganic salt and water to obtain an aqueous phase A; and mixing a peroxide initiator and water to obtain an aqueous phase B; and passing the first oil phase, aqueous phase A, and aqueous phase B into a first continuous emulsification device to obtain a first emulsion;

[0036] The acrylate monomers include isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of 62:38. The crosslinker includes ethylene glycol diacrylate, butylene glycol dimethacrylate, and trimethylol triacrylate in a weight ratio of 1:0.3:1.6. The peroxide initiator is ammonium persulfate. The surfactants include Tween-60, Span-80, and an alkyl glycoside in a weight ratio of 1:1.4:0.6. The photoinitiator is benzophenone.

[0037] The weight ratio of the acrylate monomer, the crosslinking agent, the photoinitiator and the surfactant is 80:1.2:2.3:4.4.

[0038] The volume ratio of the first oil phase, aqueous phase A and aqueous phase B is 1:32:7. Aqueous phase A is a 3 wt% calcium chloride aqueous solution; aqueous phase B contains 12 wt% peroxide initiator.

[0039] The first continuous emulsification unit operates as follows: First oil phase flow rate: 20 L / min; Water phase A flow rate: 5 L / min; Water phase B flow rate: 10 L / min. Premixing stage: The first oil phase and Water phase A are initially mixed in a Y-type static mixer to form a coarse emulsion. This coarse emulsion then enters a three-stage high-shear emulsification pump: the first stage at 2000 rpm breaks the oil phase into large droplets (D50: 152.6 μm). The second stage at 5000 rpm refines the droplets to a D50 of 65.9 μm. The third stage at 7000 rpm homogenizes the emulsion to a D50 of 46.1 μm. The sheared emulsion then enters an inline mixer, where Water phase B is simultaneously injected (via a sidestream injector) and mixed under low shear (450 rpm) for 15 seconds.

[0040] (2) mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a second oil phase, mixing an inorganic salt and water to obtain an aqueous phase C, and mixing a peroxide initiator, carboxymethyl cellulose grafted acrylic acid, and water to obtain an aqueous phase D; passing the second oil phase, aqueous phase C, and aqueous phase D into a second continuous emulsification device to obtain a second emulsion;

[0041] The acrylate monomers include isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of 62:38. The crosslinker includes ethylene glycol diacrylate, butylene glycol dimethacrylate, and trimethylol triacrylate in a weight ratio of 1:0.3:1.6. The peroxide initiator is ammonium persulfate. The surfactants include Tween-60, Span-80, and an alkyl glycoside in a weight ratio of 1:1.4:0.6. The photoinitiator is benzophenone.

[0042] The weight ratio of the acrylate monomer, the crosslinking agent, the photoinitiator and the surfactant is 80:1.2:2.3:4.4.

[0043] The volume ratio of the second oil phase, aqueous phase C, and aqueous phase D was 1:32:7. Aqueous phase C was a 3 wt% calcium chloride aqueous solution. Aqueous phase D contained 13 wt% peroxide initiator and 4 wt% carboxymethyl cellulose grafted with acrylic acid.

[0044] The second continuous emulsification unit operates as follows: Second oil phase flow rate: 20 L / min; Aqueous Phase C flow rate: 5 L / min; Aqueous Phase D flow rate: 10 L / min. Premixing stage: The second oil phase and aqueous phase C are initially mixed in a Y-type static mixer to form a coarse emulsion. This coarse emulsion then enters a three-stage high-shear emulsification pump: the first stage, at 3000 rpm, breaks the oil phase into large droplets (D50: 101.3 μm). The second stage, at 6000 rpm, refines the droplets to a D50 of 32.5 μm. The third stage, at 8000 rpm, homogenizes the emulsion to a D50 of 15.4 μm. The sheared emulsion then enters an inline mixer, where aqueous phase D is simultaneously injected (via a sidestream injector) and mixed under low shear (500 rpm) for 15 seconds.

[0045] (3) Apply the first emulsion to the upper surface of the non-woven fabric with a thickness of 0.5 mm, and the second emulsion to the lower surface of the non-woven fabric with a thickness of 1.5 mm, using a wavelength of 450 nm and an intensity of 55 mW / cm 2 The film was irradiated with light for 100 seconds, placed in a steam tunnel oven for curing for 5 minutes, and after drying and cutting, the absorption layer was obtained.

[0046] The preparation method of carboxymethyl cellulose grafted acrylic acid comprises the following steps:

[0047] (1) Under a nitrogen atmosphere, 10 parts by weight of carboxymethyl cellulose and 220 parts by weight of water were mixed, heated to 62° C., and stirred to dissolve to obtain a carboxymethyl cellulose aqueous solution;

[0048] (2) Use 2 wt% sodium hydroxide solution to adjust the pH value of 60 parts by weight of methacrylic acid to neutral, add it to the carboxymethyl cellulose aqueous solution, continue to add 0.07 parts by weight of N,N-methylenebisacrylamide, stir evenly, add 1 part by weight of sodium persulfate, heat to 46 ° C, keep warm for 3.5 hours, wash twice with ethanol and water in sequence, and dry to obtain carboxymethyl cellulose grafted with acrylic acid.

[0049] The preparation method of the highly absorbent and leak-proof 3D liquid sanitary napkin comprises the following steps: the surface non-woven fabric is embossed at high temperature to form a 3D texture; the surface layer, the guide layer, the absorbent layer and the leak-proof layer are sequentially laminated from top to bottom and combined into a sanitary napkin by hot pressing.

[0050] The surface layer is made of non-woven fabric, and the anti-leakage layer is made of PET film, which are heat-pressed. In addition, the preparation method of the liquid sanitary napkin of this embodiment also includes the process of preparing wings, applying adhesive on the back of the anti-leakage layer, and adhering release paper.

[0051] Example 2

[0052] This embodiment provides a highly absorbent and leak-proof 3D liquid sanitary napkin, which comprises, from top to bottom, a surface layer, an absorbent layer, and a leak-proof layer; a method for preparing the absorbent layer comprises the following steps:

[0053] (1) Mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a first oil phase; mixing an inorganic salt and water to obtain an aqueous phase A; and mixing a peroxide initiator and water to obtain an aqueous phase B; and passing the first oil phase, aqueous phase A, and aqueous phase B into a first continuous emulsification device to obtain a first emulsion;

[0054] The acrylate monomer includes isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of 60:40. The crosslinker includes ethylene glycol diacrylate, butylene glycol dimethacrylate, and trimethylol triacrylate in a weight ratio of 1:0.2:1.7. The peroxide initiator is ammonium persulfate. The surfactant includes Tween-60, Span-80, and an alkyl glycoside in a weight ratio of 1:1.5:0.5. The photoinitiator is benzophenone.

[0055] The weight ratio of acrylate monomer, crosslinker, photoinitiator and surfactant is 80:1:2:4.

[0056] The volume ratio of the first oil phase, aqueous phase A and aqueous phase B is 1:30:10. Aqueous phase A is a 3 wt% calcium chloride aqueous solution; aqueous phase B contains 15 wt% peroxide initiator.

[0057] The first continuous emulsification unit operates as follows: First oil phase flow rate: 20 L / min; Water phase A flow rate: 5 L / min; Water phase B flow rate: 10 L / min. Premixing stage: The first oil phase and Water phase A are initially mixed in a Y-type static mixer to form a coarse emulsion. This coarse emulsion then enters a three-stage high-shear emulsification pump: the first stage at 2000 rpm breaks the oil phase into large droplets (D50: 155.1 μm). The second stage at 5000 rpm refines the droplets to a D50 of 64.7 μm. The third stage at 7000 rpm homogenizes the emulsion to a D50 of 45.5 μm. The sheared emulsion then enters an inline mixer, where Water phase B is simultaneously injected (via a sidestream injector) and mixed under low shear (450 rpm) for 15 seconds.

[0058] (2) mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant to obtain a second oil phase, mixing an inorganic salt and water to obtain an aqueous phase C, and mixing a peroxide initiator, carboxymethyl cellulose grafted acrylic acid, and water to obtain an aqueous phase D; passing the second oil phase, aqueous phase C, and aqueous phase D into a second continuous emulsification device to obtain a second emulsion;

[0059] The acrylate monomer includes isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of 60:40. The crosslinker includes ethylene glycol diacrylate, butylene glycol dimethacrylate, and trimethylol triacrylate in a weight ratio of 1:0.2:1.7. The peroxide initiator is ammonium persulfate. The surfactant includes Tween-60, Span-80, and an alkyl glycoside in a weight ratio of 1:1.5:0.5. The photoinitiator is benzophenone.

[0060] The weight ratio of acrylate monomer, crosslinker, photoinitiator and surfactant is 80:1:2:4.

[0061] The volume ratio of the second oil phase, aqueous phase C, and aqueous phase D is 1:30:10. Aqueous phase C is a 3 wt% calcium chloride aqueous solution; aqueous phase D contains 10 wt% peroxide initiator and 5 wt% carboxymethyl cellulose grafted with acrylic acid.

[0062] The second continuous emulsification unit operates as follows: Second oil phase flow rate: 20 L / min; Aqueous Phase C flow rate: 5 L / min; Aqueous Phase D flow rate: 10 L / min. Premixing stage: The second oil phase and aqueous phase C are initially mixed in a Y-type static mixer to form a coarse emulsion. This coarse emulsion then enters a three-stage high-shear emulsification pump: the first stage, at 3000 rpm, breaks the oil phase into large droplets (D50: 100.5 μm). The second stage, at 6000 rpm, refines the droplets to a D50 of 30.8 μm. The third stage, at 8000 rpm, homogenizes the emulsion to a D50 of 15.1 μm. The sheared emulsion then enters an inline mixer, where aqueous phase D is simultaneously injected (via a sidestream injector) and mixed under low shear (500 rpm) for 15 seconds.

[0063] (3) Apply the first emulsion to the upper surface of the non-woven fabric with a thickness of 0.5 mm, and the second emulsion to the lower surface of the non-woven fabric with a thickness of 1.5 mm, using a wavelength of 450 nm and an intensity of 55 mW / cm 2 The film was irradiated with light for 100 seconds, placed in a steam tunnel oven for curing for 5 minutes, and after drying and cutting, the absorption layer was obtained.

[0064] The preparation method of carboxymethyl cellulose grafted acrylic acid comprises the following steps:

[0065] (1) Under a nitrogen atmosphere, 10 parts by weight of carboxymethyl cellulose and 230 parts by weight of water were mixed, heated to 60° C., and stirred to dissolve to obtain a carboxymethyl cellulose aqueous solution;

[0066] (2) Use 2 wt% sodium hydroxide solution to adjust the pH value of 60 parts by weight of methacrylic acid to neutral, add it to the carboxymethyl cellulose aqueous solution, continue to add 0.07 parts by weight of N,N-methylenebisacrylamide, stir evenly, add 1 part by weight of sodium persulfate, heat to 50°C, keep warm for 3 hours, wash twice with ethanol and water in sequence, and dry to obtain carboxymethyl cellulose grafted with acrylic acid.

[0067] The preparation method of the highly absorbent and leak-proof 3D liquid sanitary napkin comprises the following steps: the surface non-woven fabric is embossed at high temperature to form a 3D texture; the surface layer, the guide layer, the absorbent layer and the leak-proof layer are sequentially laminated from top to bottom and combined into a sanitary napkin by hot pressing.

[0068] The surface layer is made of non-woven fabric, and the anti-leakage layer is made of PET film, which are heat-pressed. In addition, the preparation method of the liquid sanitary napkin of this embodiment also includes the process of preparing wings, applying adhesive on the back of the anti-leakage layer, and adhering release paper.

[0069] Comparative Example 1

[0070] The difference between this comparative example and Example 1 is that the acrylic acid ester monomer is isodecyl methacrylate.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that the acrylic acid ester monomer comprises isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of 50:50.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 1 is that the acrylic acid ester monomer comprises isooctyl acrylate and isooctyl methacrylate in a weight ratio of 62:38.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 1 is that the crosslinking agent is trimethylol triacrylate.

[0077] Comparative Example 5

[0078] The difference between this comparative example and Example 1 is that the cross-linking agent comprises ethylene glycol diacrylate and trimethylol triacrylate in a weight ratio of 1:1.6.

[0079] Comparative Example 6

[0080] The difference between this comparative example and Example 1 is that the cross-linking agent comprises ethylene glycol diacrylate, butylene glycol dimethacrylate and trimethylol triacrylate in a weight ratio of 0.3:1.6:1.

[0081] Comparative Example 7

[0082] The difference between this comparative example and Example 1 is that the surfactant comprises Tween-60, Span-80 and alkyl glycoside in a weight ratio of 1.4:0.6:1.

[0083] Comparative Example 8

[0084] The difference between this comparative example and Example 1 is that the surfactant is Span-80.

[0085] Comparative Example 9

[0086] The difference between this comparative example and Example 1 is that the surfactant includes Tween-60 and Span-80 in a weight ratio of 1:0.6.

[0087] Comparative Example 10

[0088] The difference between this comparative example and Example 1 is that the surfactant is the surfactant in Example 1 of the Chinese patent publication No. CN 116421766 B which discloses a method for preparing a liquid sanitary napkin absorbent core.

[0089] Performance Testing

[0090] (1) Apply the first emulsion to the upper surface of the non-woven fabric with a thickness of 0.5 mm, using a wavelength of 450 nm and an intensity of 55 mW / cm 2 The film was irradiated with light for 100 seconds, placed in a steam tunnel oven for curing for 5 minutes, dried, and cut to obtain the guide layer of the absorption layer. Its performance was tested.

[0091] Liquid penetration time: refer to FZ / T 60017-1993 Test method for liquid penetration of thin nonwoven fabrics for sanitary use to measure the liquid penetration time.

[0092] Liquid holding rate: Place the diversion layer (mass m1) in artificial menstrual blood and allow it to fully swell for 1 hour. Then quickly place the sample on the surface of standard absorbent paper. At the same time, press a standard pressure block with a length and width of 100mm×100mm and a mass of 1.20kg on the sample. After pressurizing for 1 minute, remove the standard pressure block and measure the mass m2. The liquid holding rate is determined as (m2-m1) / m1×100%. The lower the liquid holding rate, the better the continuous diversion ability of the diversion layer.

[0093] (2) With reference to GB / T14207-2024, the water absorption rate of the absorbent layers prepared in Examples 1-2 and Comparative Examples 1-10 was measured. The formula for water absorption rate = (mass after water absorption - mass before water absorption) / mass before water absorption.

[0094] The results are shown in Table 1.

[0095] Table 1 Performance test results

[0096]

[0097] It can be seen from Table 1 that the absorption layer prepared in Example 1-2 has high flow conductivity and strong liquid absorption capacity.

[0098] In Comparative Examples 1-3, the type and ratio of the acrylate monomer 1 were changed. Different acrylate monomers have different balances of hydrophilicity and hydrophobicity. Under these conditions, the emulsification effect of the surfactant was poor, resulting in a decrease in the conductivity of the absorption layer.

[0099] In Comparative Examples 4-6, the type and ratio of the crosslinking agent are changed. The reactivity of the crosslinking agent affects the growth mode of the polymer chain and the crosslinking mode, thereby affecting the size and shape of the pores, and the conductivity of the absorption layer decreases.

[0100] In Comparative Examples 7-10, the types and ratios of the surfactants were changed, and the liquid absorption capacity of the absorption layer decreased.

[0101] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A highly absorbent and leak-proof 3D liquid sanitary napkin, characterized in that: From top to bottom, it includes a surface layer, an absorption layer and a leak-proof layer; the preparation method of the absorption layer includes the following steps: (1) Mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant in a weight ratio of 80:(1-1.5):(2-2.5):(4-5) to obtain an oil phase 1; mixing an inorganic salt and water to obtain an aqueous phase A; and mixing a peroxide initiator and water to obtain an aqueous phase B; introducing the oil phase 1, aqueous phase A, and aqueous phase B in a volume ratio of 1:(30-35):(5-10) into a continuous emulsifying device 1 to obtain an emulsion 1; (2) mixing an acrylate monomer, a crosslinking agent, a photoinitiator, and a surfactant in a weight ratio of 80:(1-1.5):(2-2.5):(4-5) to obtain an oil phase 2, mixing an inorganic salt and water to obtain an aqueous phase C, and mixing a peroxide initiator, carboxymethyl cellulose grafted acrylic acid, and water to obtain an aqueous phase D; introducing the oil phase 2, aqueous phase C, and aqueous phase D in a volume ratio of 1:(30-35):(5-10) into a continuous emulsifying device 2 to obtain an emulsion 2; (3) applying emulsion 1 to the upper surface of the non-woven fabric and applying emulsion 2 to the lower surface of the non-woven fabric, and then dehydrating and drying the non-woven fabric after light and steam treatment to obtain an absorption layer; The acrylate monomers are isodecyl methacrylate and tetradecyl methacrylate in a weight ratio of (60-65):(35-40); the crosslinking agents are ethylene glycol diacrylate, butylene glycol dimethacrylate and trihydroxymethyl triacrylate in a weight ratio of 1:(0.2-0.4):(1.5-1.7); and the surfactants are Tween-60, Span-80 and alkyl glycoside in a weight ratio of 1:(1.3-1.5):(0.5-0.7).

2. The high-absorption and side-leakage-proof 3D liquid sanitary napkin according to claim 1, characterized in that: The peroxide initiator is selected from one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

3. The high-absorbency, side-leakage-proof 3D liquid sanitary napkin according to claim 1, characterized in that: The photoinitiator is selected from one or more of benzophenone, benzil, thioxanthone and benzyl ketal.

4. The high-absorbency and side-leakage-proof 3D liquid sanitary napkin according to claim 1, characterized in that: The aqueous phase A and the aqueous phase C contain 3 wt% calcium chloride; The aqueous phase B and the aqueous phase D both contain 10-15 wt % of a peroxide initiator and 3-5 wt % of carboxymethyl cellulose grafted with acrylic acid.

5. The high-absorbency and side-leakage-proof 3D liquid sanitary napkin according to claim 1, characterized in that: The preparation method of carboxymethyl cellulose grafted acrylic acid comprises the following steps: (1) Under a nitrogen atmosphere, 10 parts by weight of carboxymethyl cellulose and 200-230 parts by weight of water were mixed and stirred to dissolve to obtain a carboxymethyl cellulose aqueous solution; (2) After adjusting 60 parts by weight of methacrylic acid to neutrality, add it to the carboxymethyl cellulose aqueous solution, continue to add 0.06-0.09 parts by weight of N,N-methylenebisacrylamide, stir evenly, add sodium persulfate, heat to 45-50°C, keep warm for 3-4 hours, wash, and dry to obtain carboxymethyl cellulose grafted with acrylic acid.

6. A method for preparing the highly absorbent and side-leakage-proof 3D liquid sanitary napkin according to any one of claims 1 to 5, characterized in that: The surface layer is embossed at high temperature to form a 3D texture, and the surface layer, absorption layer and leakage-proof layer are laminated from top to bottom in sequence and combined into a sanitary napkin through heat pressing.

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