A composite finishing agent with rapid liquid absorption and low re-imbibition and a preparation method thereof

Abstract

The present application relates to the field of absorbent articles, and particularly relates to a compound finishing agent with rapid liquid absorption and low back penetration and a preparation method thereof, comprising 5-20 parts of flow guide functional agent, 1.5-8 parts of liquid locking functional agent, 2-5 parts of lubricating auxiliary agent, and the balance being water, wherein the flow guide functional agent is one or more of sodium sulfobutane disulfonate, polyether modified siloxane, alkyl glycoside, isomeric alcohol polyoxyethylene ether, and poloxamer, the total mass ratio of water-soluble calcium salt and high molecular crosslinking thickening agent is 1.5:1-3:1, and the lubricating auxiliary agent is polyethylene glycol. Through implementation of the present application, rapid downward penetration and low back penetration of liquid can be achieved.

Description

Technical Field

[0001] This invention relates to the field of absorbent products, specifically to a composite finishing agent with rapid liquid absorption and low backflow, and its preparation method. Background Technology

[0002] The core performance of disposable absorbent products such as sanitary napkins, diapers, and nursing pads depends on the absorbent core's ability to conduct, absorb, and retain liquid. Slow liquid seepage, high rewetting rates, and susceptibility to side leakage are common technical challenges in the industry. With continuously upgrading consumer demands, consumers are increasingly requiring products to be dry and comfortable, leading to a trend towards thinner, more functional, and higher-end absorbent products.

[0003] To address these shortcomings, existing technologies employ various methods. For instance, in the modification of superabsorbent polymers (SAPs), cross-linked, salt-tolerant superabsorbent resins are prepared using reverse suspension polymerization, and chelating agents are introduced to improve salt absorption rates. Alternatively, free radical polymerization of acrylic acid and modified soy protein isolate is used to obtain resins with high absorbency and biodegradability. To solve the problems of SAP clogging and poor liquid permeability after absorbing water, some technologies adopt a "core-shell" structure design and introduce inert solid hydrophilic particles as pore-forming agents during surface treatment to improve liquid diffusion performance. Furthermore, to reduce safety hazards, some solutions use non-azo initiators and optimize the polymerization process to control the residual monomer content at a low level.

[0004] In addition, the molding formulations of absorbent layers or alternative materials are being optimized: for example, water-absorbing particles are uniformly mixed with a special molding hot melt adhesive (containing polymers, plasticizers, tackifying resins, etc.) before molding to solve the problems of water-absorbing particles easily transferring, falling off, and clumping after absorbing water; another approach uses raw materials such as acrylate monomers, emulsifiers, and short fibers to prepare foam-type absorbent materials, using short fibers to enhance the toughness and strength of the material to improve the reabsorption performance, while avoiding the risk that particulate SAP may migrate to the skin surface.

[0005] However, the aforementioned formulation improvement methods still have many shortcomings. The chemical modification process for SAP is complex and costly, and some modification schemes may introduce new organic solvent residues, posing safety risks. While using a "core-shell" structure or pore-forming agents can improve liquid permeability, it often negatively impacts the water absorption ratio or water retention capacity of SAP, making it difficult to balance rapid absorption and high water retention. In the absorbent layer formulation, the addition of hot melt adhesive can fix the particles, but its hydrophobic properties may hinder liquid penetration, thus reducing the absorption rate. Furthermore, the preparation process of foam materials is still immature, and their long-term stability and reabsorption performance after multiple absorptions remain to be verified.

[0006] Therefore, how to simultaneously achieve rapid liquid infiltration, low backflow, and high water retention capacity remains a technical challenge that urgently needs to be solved in the field of absorbent products. Summary of the Invention

[0007] The present invention aims to provide a composite finishing agent with rapid liquid absorption and low backflow, and a method for preparing the same, so as to achieve rapid liquid penetration and low backflow effect.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a composite finishing agent with rapid liquid absorption and low backflow, comprising 5-20 parts of a flow-guiding agent, 1.5-8 parts of a liquid-locking agent, 2-5 parts of a lubricating agent, and the remainder being water.

[0009] Preferably, as an improvement, the diluent is one or more of sodium dioctyl sulfosuccinate, polyether-modified siloxane, alkyl glycoside, isomeric alcohol polyoxyethylene ether, and poloxamer.

[0010] Preferably, as an improvement, the liquid-locking functional agent includes a water-soluble calcium salt and a polymeric crosslinking thickener.

[0011] Preferably, as an improvement, the total mass ratio of water-soluble calcium salt to polymeric crosslinking thickener is 1.5:1 to 3:1.

[0012] Preferably, as an improvement, the amount of water-soluble calcium salt added is 1 to 6 parts, and the amount of polymer crosslinking thickener added is 0.5 to 2 parts.

[0013] Preferably, as an improvement, the water-soluble calcium salt is one or more of calcium chloride, calcium lactate, and calcium gluconate; the polymer crosslinking thickener is composed of water-soluble cellulose and water-soluble polysaccharides, wherein the mass ratio of water-soluble cellulose to water-soluble polysaccharides is 1:1 to 1:2. If the ratio exceeds this range, the absorption will be slowed down due to the blockage of the flow channel by excessive crosslinking, or the liquid-locking failure and the increase of backflow will be caused by insufficient crosslinking.

[0014] Preferably, as an improvement, the water-soluble cellulose is one or more of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose; and the water-soluble polysaccharide is one or more of carboxymethyl chitosan, hydroxypropyl chitosan, and chitosan quaternary ammonium salt.

[0015] The lubricating agent is polyethylene glycol (PEG), and the polyethylene glycol is one or more of PEG400, PEG600, and PEG800.

[0016] A method for preparing a composite finishing agent with rapid liquid absorption and low backflow, characterized by comprising the following steps: S1. Add the lubricating aid and the high molecular weight crosslinking thickener in the liquid-locking functional agent to water, and stir at high speed to disperse them evenly to form a homogeneous solution; S2. Add the water-soluble calcium salt from the liquid-locking agent to the solution prepared in S1, and stir until homogeneous; S3. Add the flow-guiding agent under slow stirring and mix evenly to obtain the composite finishing agent.

[0017] The principles and advantages of this solution are as follows: The composite finishing agent in this solution utilizes the synergistic effect of its components to achieve a continuous dynamic response process of "rapid flow guidance—directional conduction—promoting coagulation and locking in liquid." The flow-guiding agent can rapidly reduce the surface tension of the liquid, eliminate the lag time in the initial contact with the liquid, and achieve rapid adsorption and penetration of the liquid. The lubricating aid has both plasticizing and film-forming effects, optimizing the processing performance of the coating liquid, while providing molecular-level lubrication channels to accelerate liquid conduction.

[0018] The liquid-locking agent incorporates water-soluble cellulose and water-soluble polysaccharides as high-molecular cross-linking thickening polymers. On one hand, it forms a stable hydrophilic network, enhancing the bonding strength between the coating and the core and preventing swelling and detachment upon contact with water. On the other hand, the cellulose imparts excellent rheological pseudoplasticity to the fluid, providing a strong and robust supporting framework. The dense active groups of the polysaccharides undergo in-situ coordination cross-linking with the water-soluble calcium salts, providing high-density cross-linked nodules. This not only solves the problem of powder shedding and brittleness in high-salt inorganic powders but also ensures that the coating remains tightly anchored to the fiber surface even when subjected to large amounts of body fluid, maintaining continuous flow conduction and liquid-locking functions.

[0019] On the other hand, it enables rapid flocculation and locking of liquids, inhibiting pressure-induced backflow from the source. The liquid-locking functional agent encapsulates excess reserves of active calcium ions and functional polysaccharides, exhibiting targeted phase change solidification capabilities for complex biological fluids with different components: For high-viscosity blood, the free calcium ions released in the network instantly activate the cascade coagulation reaction of plasma proteins as clotting factors. At the same time, the active polysaccharides strongly adsorb red blood cells through charge attraction, triggering rapid flocculation. The two work synergistically to transform free blood into an irreversible solid gel in situ, completely depriving the blood of its fluidity and solving the industry pain point of blood causing pressure-induced backflow in conventional cores. For high-flow-rate urine, the polymer chains in the cross-linked network undergo a deep physical ionic cross-linking reaction with multivalent metal ions in the body fluid environment upon absorbing and swelling, resulting in a high-strength gel. This gel network physically locks free water molecules inside the mesh, making them difficult to squeeze out even under pressure, thus preventing backflow.

[0020] Through the above synergy, the original slow radial diffusion of the liquid is transformed into high-speed longitudinal diffusion, which significantly improves the absorption rate, greatly increases the longitudinal diffusion length, significantly improves the utilization rate of the front and rear ends of the core, effectively blocks the occurrence of backflow, greatly eliminates the risk of leakage, and significantly reduces the amount of pressure-induced backflow. Detailed Implementation

[0021] The following detailed description illustrates the specific implementation method: Example 1 A composite finishing agent with rapid liquid absorption and low backflow comprises 15 parts of isomeric alcohol polyoxyethylene ether, 1 part of calcium chloride, 0.2 parts of sodium carboxymethyl cellulose, 0.3 parts of hydroxypropyl chitosan, 3 parts of PEG400, and 80.5 parts of water.

[0022] Weigh out the components according to the above-mentioned mass proportions, add PEG400, sodium carboxymethyl cellulose, and hydroxypropyl chitosan to water, and disperse them at high speed to form a uniform solution; continue to add calcium chloride and stir until uniform; add isomeric alcohol polyoxyethylene ether under slow stirring, and mix evenly to obtain the composite finishing agent. The stirring speed is 20-200 r / min. If the stirring speed is too fast, it will introduce air bubbles, cause shear degradation of polymers, uneven dispersion of the flow-conducting agent, and premature gelation due to system heating. In this embodiment, 50-100 r / min is preferred.

[0023] Example 2 A composite finishing agent with rapid liquid absorption and low backflow comprises 12 parts of polyether-modified siloxane, 2.5 parts of calcium chloride, 0.5 parts of hydroxyethyl cellulose, 1 part of carboxymethyl chitosan, 3.5 parts of PEG600, and 80.5 parts of water.

[0024] Example 3 A composite finishing agent with rapid liquid absorption and low backflow comprises 20 parts alkyl glycoside, 2 parts calcium lactate, 1 part hydroxyethyl cellulose, 1 part chitosan quaternary ammonium salt, 2 parts PEG800, and 74 parts water.

[0025] Example 4 A composite finishing agent with rapid liquid absorption and low backflow comprises 19 parts sodium dioctyl sulfosuccinate, 2 parts calcium chloride, 0.5 parts sodium carboxymethyl cellulose, 0.5 parts carboxymethyl chitosan, 2 parts PEG400, and 75 parts water.

[0026] Example 5 A composite finishing agent with rapid liquid absorption and low backflow comprises 14 parts alkyl glycoside, 1 part poloxamer, 2 parts calcium gluconate, 0.5 parts hydroxypropyl methylcellulose, 0.5 parts hydroxypropyl chitosan, 2 parts PEG400, and 80 parts water.

[0027] Example 6 A composite finishing agent with rapid liquid absorption and low backflow comprises 10 parts of isomeric alcohol polyoxyethylene ether, 1 part of calcium chloride, 2 parts of sodium carboxymethyl cellulose, 3 parts of hydroxypropyl chitosan, 3 parts of PEG400, and 81 parts of water.

[0028] Example 7 A composite finishing agent with rapid liquid absorption and low backflow comprises 6 parts polyether-modified siloxane, 3 parts calcium chloride, 0.5 parts hydroxyethyl cellulose, 1 part carboxymethyl chitosan, 4 parts PEG600, and 85.5 parts water.

[0029] Example 8 A composite finishing agent with rapid liquid absorption and low backflow comprises 12 parts alkyl glycoside, 6 parts calcium lactate, 1 part hydroxyethyl cellulose, 1 part chitosan quaternary ammonium salt, 4 parts PEG800, and 76 parts water.

[0030] Example 9 A composite finishing agent with rapid liquid absorption and low backflow comprises 10 parts sodium dioctyl sulfosuccinate, 5 parts calcium chloride, 1 part sodium carboxymethyl cellulose, 1 part carboxymethyl chitosan, 5 parts PEG400, and 78 parts water.

[0031] Example 10 A composite finishing agent with rapid liquid absorption and low backflow, comprising 8 parts alkyl glycoside, 4 parts poloxamer, 3 parts calcium gluconate, 0.5 parts hydroxypropyl methylcellulose, 0.5 parts hydroxypropyl chitosan, 3 parts PEG400, and 81 parts water.

[0032] Comparative Example 1 A composite finishing agent with rapid liquid absorption and low backflow comprises 2.5 parts calcium chloride, 0.5 parts hydroxyethyl cellulose, 1 part carboxymethyl chitosan, 3.5 parts PEG600, and 92.5 parts water.

[0033] Comparative Example 2 A composite finishing agent with rapid liquid absorption and low backflow comprises 12 parts of polyether-modified siloxane, 3.5 parts of PEG600, and 84.5 parts of water.

[0034] Comparative Example 3 A composite finishing agent with rapid liquid absorption and low backflow comprises 12 parts of polyether-modified siloxane, 2.5 parts of zinc salt, 0.5 parts of hydroxyethyl cellulose, 1 part of carboxymethyl chitosan, 3.5 parts of PEG600, and 80.5 parts of water.

[0035] Comparative Example 4 Based on Example 2, the difference in this comparative example is: 1 part calcium chloride, 1 part sodium carboxymethyl cellulose, 1 part carboxymethyl chitosan, and 81.5 parts water.

[0036] Comparative Example 5 Based on Example 2, the difference in this comparative example is: 10 parts calcium chloride, 1 part sodium carboxymethyl cellulose, 1 part carboxymethyl chitosan, and 76 parts water.

[0037] Performance testing The composite finishing agent is prepared onto the absorbent product as follows: A slot extrusion coating method is used to coat the absorbent core along its length, forming three functional strips. These strips are parallel to each other and centrally located, symmetrically distributed along the central axis of the core in the central region. The strip spacing is 15 mm, the strip width is 2 mm, and the feed rate per unit length is 0.6 mg / mm. After drying and curing, an absorbent core with functional strips is obtained. The absorbent core is then incorporated into the absorbent product, which is a composite product consisting of a top layer, a flow-guiding layer, an absorbent core, and a leak-proof bottom layer, layered sequentially from top to bottom. The flow-guiding layer is tightly adhered to the top surface of the absorbent core to cover the functional strips.

[0038] Referring to the test methods for absorption rate and rewetting in the national standards GB / T28004.1-2021 "Baby Diapers" and GB / T 8939-2025 "Sanitary Napkins", the test solutions were physiological saline and pig blood, respectively.

[0039] First absorption time (s): The time required for the sample to absorb 5 mL of test solution for the first time.

[0040] Second absorption time (s): The time required for the sample to absorb 5 mL of test solution for the second time.

[0041] Reabsorption volume (g): The mass of test solution returned to the surface layer after the sample absorbs 10 mL of test solution.

[0042] In addition, in order to verify the performance difference between absorbent products prepared with finishing agents and absorbent products without finishing agents, a comparative example 6 was prepared. The absorbent product of comparative example 6 had no functional strips made by scraping the composite finishing agent on its absorbent core.

[0043] Table 1 shows the test results of absorption time and reabsorption volume of physiological saline in Examples 1-5 and Comparative Examples 1-6.

[0044] Table 2 shows the test results of absorption time and reabsorption volume of pig blood in Examples 6-10 and Comparative Examples 1-6.

[0045]

[0046] Table 1 Results of saline test

[0047] Table 2. Results of pig blood test Combining the test data for physiological saline and pig blood in Tables 1 and 2, it can be seen that the composite finishing agent of this invention, with the synergistic effect of the flow-guiding agent, the liquid-locking agent, and the lubricating agent, effectively achieves the technical effects of rapid absorption, directional flow guidance, and strong liquid-locking in absorbent products. Compared with conventional absorbent products, the absorbent products prepared using this invention show significantly shorter first and second absorption rates, significantly improved liquid permeation rate and continuous absorption capacity; the amount of backflow is greatly reduced, and the liquid-locking performance is excellent. Whether for physiological saline or simulated pig blood, it exhibits excellent absorbency, dryness, and leak-proof effect, effectively solving the industry problems of slow absorption speed, large backflow, and easy side leakage. It meets the performance requirements of high-end absorbent products and has strong practicality and industrialization value.

[0048] Meanwhile, the above experiments show that when the composite finishing agent includes the following components: 12-20 parts of a flow-guiding agent, 1.5-4 parts of a liquid-locking agent, 2-3.5 parts of a lubricating agent, and the remainder being water, it is used in the diaper industry; when the composite finishing agent includes the following components and mass percentages: 6-12 parts of a flow-guiding agent, 4-8 parts of a liquid-locking agent, 3-5 parts of a lubricating agent, and the remainder being water, it is used in the sanitary napkin industry.

[0049] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A composite finishing agent with rapid liquid absorption and low backflow, characterized in that: It includes 5-20 parts of a flow-guiding agent, 1.5-8 parts of a liquid-locking agent, 2-5 parts of a lubricating agent, and the remainder is water.

2. The composite finishing agent with rapid liquid absorption and low backflow as described in claim 1, characterized in that: The fluid-conducting functional agent is one or more of the following: sodium dioctyl sulfosuccinate, polyether-modified siloxane, alkyl glycoside, isomeric alcohol polyoxyethylene ether, and poloxamer.

3. The composite finishing agent with rapid liquid absorption and low backflow as described in claim 2, characterized in that: The liquid-locking functional agent includes water-soluble calcium salts and polymeric cross-linking thickeners.

4. A composite finishing agent with rapid liquid absorption and low backflow as described in claim 3, characterized in that: The total mass ratio of water-soluble calcium salt to polymeric crosslinking thickener is 1.5:1 to 3:

1.

5. A composite finishing agent with rapid liquid absorption and low backflow as described in claim 4, characterized in that: The amount of water-soluble calcium salt added is 1 to 6 parts, and the amount of polymer crosslinking thickener added is 0.5 to 2 parts.

6. The composite finishing agent with rapid liquid absorption and low backflow as described in claim 5, characterized in that: The water-soluble calcium salt is one or more of calcium chloride, calcium lactate, and calcium gluconate; the polymeric crosslinking thickener is composed of a mixture of water-soluble cellulose and water-soluble polysaccharides.

7. A composite finishing agent with rapid liquid absorption and low backflow as described in claim 6, characterized in that: The water-soluble cellulose is one or more of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose; the water-soluble polysaccharide is one or more of carboxymethyl chitosan, hydroxypropyl chitosan, and chitosan quaternary ammonium salt.

8. A composite finishing agent with rapid liquid absorption and low backflow as described in claim 7, characterized in that: The lubricating agent is polyethylene glycol, and the polyethylene glycol is one or more of PEG400, PEG600, and PEG800.

9. A method for preparing a composite finishing agent with rapid liquid absorption and low backflow, characterized in that: Includes the following steps: S1. Add the lubricating aid and the high molecular crosslinking thickener in the liquid-locking functional agent to water, and stir at high speed to disperse them evenly to form a homogeneous solution; S2. Add the water-soluble calcium salt from the liquid-locking agent to the solution prepared in S1, and stir until homogeneous; S3. Add the flow-guiding agent under slow stirring and mix evenly to obtain the composite finishing agent.

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