Multi-layer composite structure with slow release function as well as preparation method and application of multi-layer composite structure

Abstract

The invention relates to the technical field of functional textile materials, in particular to a multi-layer composite structure with a slow release function and a preparation method and application of the multi-layer composite structure. The multi-layer composite structure at least comprises a middle layer, and the middle layer comprises a bottom fabric layer formed by interweaving first warp yarns and first weft yarns; and at least one outer layer is arranged on the two sides of the middle layer and comprises a surface fabric layer formed by interweaving second warp yarns and second weft yarns. In the application, the outer layer has a low-twist fluffy structure and a pearl fiber microporous structure and can quickly absorb exudate and reduce skin adhesion, the middle layer adopts modal and pearl fibers and has the functions of imbibition and capacity expansion, the liquid storage amount is increased by 40%, and the liquid storage amount is increased by 40% by adopting a first warp yarn and first weft yarn double-thread plying flow guide mode. And the vertical diffusion speed is up to 5cm / s. Through the multi-layer composite structure and the composite capsule fixed on the multi-layer composite structure, the multi-layer composite structure disclosed by the invention has a slow release function.

Description

Technical Field

[0001] This invention relates to the field of functional textile composite materials technology, and more specifically, to a multilayer composite structure with skin care, wound repair and sustained-release functions, as well as its preparation method and application. Background Technology

[0002] Traditional facial mask base fabrics have poor liquid absorption rates, less than 40%; existing medical dressings suffer from limited functionality and poor biocompatibility, while medicated dressings mostly use a coating method, resulting in uncontrollable drug release and inconsistent release times during use, leading to poor treatment effects.

[0003] In existing slow-release textiles, the release of anti-inflammatory components is uncontrollable, and the anti-inflammatory effect is delayed, taking more than 30 minutes. This fails to meet the needs of individuals with acute inflammation, such as those suffering from minor burns or acute eczema.

[0004] To address the problems existing in the prior art, we propose a multilayer composite structure with sustained-release function, its preparation method, and its application to solve the aforementioned problems. Summary of the Invention

[0005] A primary objective of this invention is to overcome at least one deficiency in the prior art and provide a multilayer composite structure with sustained-release function, its preparation method, and its application. This invention addresses industry pain points through triple innovation in multilayer composite structure, composite capsule formulation, and preparation process, thus possessing significant market competitiveness.

[0006] To achieve the above technical solution, the present invention adopts the following technical solution:

[0007] A multilayer composite structure with a slow-release function includes at least one intermediate layer, the intermediate layer including a base fabric layer woven from a first warp yarn and a first weft yarn;

[0008] And at least one outer layer is provided on both sides of the intermediate layer, the outer layer comprising a surface fabric layer woven from a second warp yarn and a second weft yarn;

[0009] In this multi-layered composite structure, composite capsules are fixed inside and on the surface of the middle and outer layers, enabling the middle and outer layers to synergistically achieve gradient slow release of active ingredients. The gradient slow release is achieved through rapid liquid absorption by the outer layer, liquid storage expansion by the middle layer, and phased release of the composite capsules in response to tissue fluid humidity.

[0010] In the above structure, according to one embodiment of the present invention, the composite capsule includes composite capsule one and / or composite capsule two;

[0011] The compound capsule contains ceramide, panthenol B5, and colloidal oats, all of which are active substances. The three active substances and the solvent are in the following proportions by weight: ceramide 5%, panthenol B5 15%, colloidal oats 10%, and solvent 70%.

[0012] The active ingredient dipotassium glycyrrhizate in the compound capsule II has a release rate of ≥80% within 5 minutes and a release rate of ≤50% within 24 hours for panthenol B5, achieving a rapid response in acute anti-inflammatory treatment.

[0013] In the above preparation method, according to one embodiment of the present invention, the ratio of ceramide, panthenol B5 and colloidal oats is 1:3:2.

[0014] In this invention, the outer layer has a low-twist, fluffy structure and a pearl fiber microporous structure, which can quickly absorb exudate and reduce skin adhesion. The middle layer uses modal and pearl fiber, which has the function of absorbing and expanding liquid, increasing the liquid storage capacity by 40%, and adopts a double-plying method of the first warp and first weft yarns to guide the flow, with a vertical diffusion speed of at least 5 cm / s. The outer layer is respectively disposed outside the middle layer, forming a double-sided terry loop structure.

[0015] In the above structure, according to one embodiment of the present invention, the first warp yarn is a 32-60 count blended yarn, and contains 35%-55% cotton, 20%-40% modal, and 15%-35% pearl fiber; the first weft yarn is a 32-60 count compact Sirospun yarn, and contains 50%-100% bamboo fiber.

[0016] The first warp and first weft yarns are twisted in a 1:1 ratio and using a double-ply twisting method. The intermediate layer, composed of the first warp and first weft yarns, forms a highly conductive slow-release layer with a vertical diffusion velocity ≥5 cm / s. The pearl fibers in the first warp yarn and the bamboo fibers in the first weft yarn form a hydrophilic and energy-storing dual-grid channel, increasing the active ingredient carrying capacity by 30%. The highly conductive slow-release layer contains a highly conductive liquid with conductive and diffusion properties. The pearl fibers are viscose fibers containing ≥90% calcium carbonate and with a fineness of 1.0–1.5 dtex.

[0017] In the above structure, according to an embodiment of the present invention, the second warp yarn is a 32-60 count loose low twist yarn, the second warp yarn contains 8%-15% pearl fiber, 5%-15% hemp staple fiber, 55% bamboo fiber and 20% cotton, the second weft yarn is a 32-60 count compact Sirospun yarn, and the second weft yarn contains 50%-100% bamboo fiber.

[0018] The second warp and second weft yarns are twisted in a 1:1 ratio and have a Z-twist twist, forming a high surface area contact layer (friction coefficient ≤ 0.25).

[0019] Pearl fiber, as a raw material for yarn, can further improve the comfort of the product and enhance the skin protection effect. The pearl fiber is soft and skin-friendly and beneficial to the nutrition of human skin. The hemp staple fiber and cotton fiber, as raw materials for yarn, can improve the yarn evenness. The pearl fiber is a viscose fiber containing ≥90% calcium carbonate and has a fineness of 1.0 to 1.5 dtex.

[0020] In the above structure, according to one embodiment of the present invention, the first warp yarn is a 40-count blended yarn, the first weft yarn is a 40-count compact Siro spun yarn, the second warp yarn is a 32-count loose low-twist yarn, and the second weft yarn is a 40-count compact Siro spun yarn.

[0021] In the above structure, according to one embodiment of the present invention, hemp short fibers, flax, and ramie can be substituted for each other after being treated with the same enzyme (pectinase 5U / g + xylanase 3U / g);

[0022] As described above, the second warp yarn and the second weft yarn constitute the tactile optimization layer of the product of this application.

[0023] In the above structure, according to one embodiment of the present invention, the intermediate layer has a honeycomb structure with a porosity ≥65%, thereby increasing the loading capacity of the composite capsule by 30%.

[0024] In the above structure, according to one embodiment of the present invention, the basis weight of the intermediate layer is 60 g / m³. 2 ~220g / m 2 .

[0025] In the above-described structure, according to an embodiment of the present invention, the active ingredients in the second composite capsule include: dipotassium glycyrrhizate and panthenol B5. Specifically, by mass, dipotassium glycyrrhizate ≤0.5% and panthenol B5 15%. The release triggering mechanism of the active ingredients in the second composite capsule is as follows: the outer layer absorbs tissue fluid secreted by the human body; the tissue fluid dissolves the capsule wall of the composite capsule; and the dipotassium glycyrrhizate release rate is ≥85% within 5 minutes, achieving rapid release of anti-inflammatory components within 5 minutes of contact with tissue fluid. The dipotassium glycyrrhizate has a molecular weight of 494.6, a small molecule with rapid penetration function, while panthenol B5 has moisturizing and repairing effects. In contrast, traditional products release ≤40% of dipotassium glycyrrhizate within 5 minutes. The release amount of the active ingredients in the composite capsule of this application is far greater than that of traditional products, resulting in a rapid anti-inflammatory response.

[0026] A method for preparing a multilayer composite structure with sustained-release function, comprising at least:

[0027] A multi-layer composite structure is prepared using a double-sided terry loom. The first warp and first weft yarns are woven into an intermediate layer, which has a honeycomb structure, a porosity ≥65%, and a basis weight of 60 g / m². 2 ~220g / m 2 ;

[0028] On both sides of the middle layer, the second warp yarn and the second weft yarn are woven into an outer layer with a double-sided loop structure;

[0029] The middle layer and the outer layer with a double-sided terry loop structure constitute a multi-layer composite structure.

[0030] In the above preparation method, according to one embodiment of the present invention, the second warp yarn contains hemp short fibers and bamboo fibers;

[0031] The hemp short fibers are treated with a combination of pectinase and xylanase, and the bamboo fibers are modified by plasma.

[0032] In the above preparation method, according to an embodiment of the present invention, the pectinase content is 5 U / g, the xylanase content is 3 U / g, the temperature of the composite treatment is 50°C, and the treatment time is 120 minutes.

[0033] In the above preparation method, according to one embodiment of the present invention, the bamboo fiber is treated with helium plasma, the vacuum degree of the environment required for helium plasma treatment is 10 Pa, and the treatment time is 90 seconds.

[0034] In the above preparation method, according to an embodiment of the present invention, the multilayer composite structure is simultaneously treated by a one-time impregnation and fixation process of impregnation liquid, and composite capsules are fixed in both the interior and surface of the multilayer composite structure, ensuring that the composite capsules penetrate into the middle layer.

[0035] The impregnation solution comprises, by weight, 8%–12% composite capsules, 0.5% penetrant, 3% binder, acetic acid (pH adjuster), and deionized water;

[0036] The composite capsule is used for sustained release of active ingredients, i.e., it has a sustained release function; the penetrant promotes the penetration of the composite capsule into the intermediate layer; the adhesive is used to fix the composite capsule, fixing it in the heat-resistant coating layer of ethyl cellulose; the pH adjuster is used to maintain the stability of ceramide, and the pH is adjusted to 5.5 by the acetic acid pH adjuster; and the deionized water is a solvent, serving as a carrier in the above-mentioned impregnation liquid;

[0037] Because the middle and outer layers of the multi-layered composite structure are all fixed with composite capsules, the middle and outer layers work together to achieve gradient sustained release of active ingredients and rapid anti-inflammatory response. The gradient sustained release is achieved through rapid liquid absorption by the outer layer, liquid storage expansion by the middle layer, and phased release by the composite capsule in response to tissue fluid moisture. The rapid anti-inflammatory response is characterized by a release of ≥85% of dipotassium glycyrrhizate in 5 minutes.

[0038] Furthermore, the adhesive is preferably a modified polyacrylate, which has soft and washable properties.

[0039] In the above preparation method, according to one embodiment of the present invention, the one-time pad-on-patch bonding process of the padding solution includes:

[0040] (1) The multi-layer composite structure is desized and refined to ensure its hydrophilicity and capillary effect >10cm / min;

[0041] (2) During the impregnation and rolling process, after one impregnation and one rolling, the roll residue rate is 80%, the temperature is 40℃, and the pressure is 0.3MPa, ensuring that the impregnation liquid penetrates the multi-layer composite structure; during the impregnation and rolling process, the impregnation pressure gradient gradually increases from 0.1MPa to 0.3MPa, so that the composite capsule enters the intermediate layer.

[0042] (3) Pre-drying: Dry with hot air at 80℃ for 2 minutes to fix the adhesive;

[0043] (4) Baking: Drying at 110℃ for 90 seconds to ensure that the outer wall of the composite capsule is firmly bonded to the heat-resistant coating layer (EC layer) of ethyl cellulose.

[0044] (5) After the above treatment, wash away the unfixed components on the multilayer composite structure with cold water, and finally dry the multilayer composite structure.

[0045] In the above preparation method, according to one embodiment of the present invention, during impregnation and rolling, the rolling operation is achieved by a rolling mill, the pressure gradient of the rolling mill is controlled at 0.1MPa to 0.3MPa, and the pressure is applied by segmented pressing; after pre-drying, it is treated by low-temperature plasma treatment in an N2 atmosphere with a power of 50W for 2 minutes.

[0046] In this invention, it is important to note that the middle layer of the multi-layer composite structure requires cross-sectional slicing to test the uniformity of capsule distribution. When combined with the composite capsule, the multi-layer composite structure produced by this invention possesses a sustained-release function, combining skin care, wound repair, and sustained-release capabilities; particularly the sustained-release function, which meets the needs of high-end medical dressings.

[0047] In the above preparation method, according to one embodiment of the present invention, the ethyl cellulose heat-resistant coating layer contains mesoporous silica, which adsorbs ceramide and delays its release; the release rate is >90% after 72 hours. The mesoporous silica is an inorganic material with a highly ordered pore structure, typically classified into micropores and mesopores. Micropores have a pore size range of less than 2 nanometers, while mesopores have a pore size range of 2-50 nanometers. This material has a large specific surface area and pore volume, making it an ideal catalyst and adsorbent. In this invention, the pore size of the mesoporous silica is 2 nanometers. The composite capsule is coated in an ethyl cellulose heat-resistant layer containing mesoporous silica (2 nm pore size), achieving a cumulative release rate of >90% after 72 hours.

[0048] In the above preparation method, according to one embodiment of the present invention, the composite capsule includes composite capsule one and / or composite capsule two;

[0049] The composite capsule one is prepared by composite capsule emulsion one; the preparation process of the composite capsule emulsion one includes: dissolving ceramide in ethanol to form solution one, dissolving panthenol B5 in water to form solution two, and dispersing colloidal oats in deionized water to form solution three.

[0050] Mix the above solutions 1, 2, and 3, add natural polysaccharides and emulsifiers, and homogenize and emulsify in a mixer to obtain compound capsule emulsion 1;

[0051] The second composite capsule is prepared by the second composite capsule emulsion; the preparation process of the second composite capsule emulsion includes: dissolving dipotassium glycyrrhizate in ethanol to form solution four, and dissolving panthenol B5 in water to form solution two;

[0052] Mix the above solutions four and two, add natural polysaccharides and emulsifiers, and homogenize and emulsify in a mixer to obtain compound capsule emulsion two.

[0053] In the above preparation method, according to one embodiment of the present invention, the temperature of the ethanol is 60°C, the natural polysaccharide includes, but is not limited to, sodium alginate, and the emulsifier includes, but is not limited to, lecithin; in the homogenization and emulsification stage, the stirring speed is 10,000 rpm, and the time is 15 minutes. The lecithin has a mass fraction of 0.8% to 1.2%.

[0054] In the above preparation method, according to an embodiment of the present invention, the composite capsule emulsion is added to a gelatin solution with a pH of 4.0, and after stirring, a gum arabic solution is added. The gelatin solution and the gum arabic solution form a composite colloid, and its pH is adjusted to 4.5.

[0055] After stirring, the composite colloid forms the capsule wall of composite capsule one and composite capsule two. Composite capsule one contains ceramide, panthenol B5 and colloidal oats, while composite capsule two contains dipotassium glycyrrhizate and panthenol B5.

[0056] After solidification, filtration, freezing and drying, tiny powdery composite capsules one and two, i.e. microcapsules, are obtained.

[0057] In the above preparation method, according to an embodiment of the present invention, the particle size of the first composite capsule is 1 μm to 1.5 μm, and the particle size of the second composite capsule is 1 μm to 3.0 μm.

[0058] In the above preparation method, according to an embodiment of the present invention, the composite capsule one contains ceramide, panthenol B5 and colloidal oats, all of which are active substances;

[0059] The above three active substances and solvents are in the following proportions by weight: ceramide 5%, panthenol B5 15%, colloidal oats 10%, and solvent 70%.

[0060] In the above preparation method, according to one embodiment of the present invention, the ratio of ceramide, panthenol B5 and colloidal oats is 1:3:2.

[0061] The response release mechanism of the composite capsule in the multi-layer composite structure of this invention is as follows: upon contact with the body's tissue fluid, the colloidal oatmeal is released first, providing anti-inflammatory sustained release within approximately 5 minutes; when humidity > 70%, panthenol B5 is continuously released, providing moisturizing and repairing effects; and ceramide is continuously released over 24 hours, providing barrier repair effects. The multi-layer composite structure of this application retains its performance even after 50 washes, and the effective release amount of ceramide is 1.22 mg / g.

[0062] In the above preparation method, according to an embodiment of the present invention, the composite capsule II contains dipotassium glycyrrhizate and panthenol B5, both of which are active substances;

[0063] The above two active substances and solvents are present in the following proportions by mass: dipotassium glycyrrhizate 0.5%, panthenol B5 15%, and solvent 84.5%.

[0064] The response release mechanism of the composite capsule II in the multi-layer composite structure of this invention is as follows: the outer layer of the multi-layer composite structure absorbs tissue fluid secreted by the human body; the tissue fluid dissolves the capsule wall of the composite capsule; and the release rate of dipotassium glycyrrhizate is ≥85% within 5 minutes, achieving rapid release of anti-inflammatory components within 5 minutes of contact with tissue fluid, while panthenol B5 is continuously released, providing moisturizing and repairing effects. The multi-layer composite structure described in this application retains its performance even after 50 washes with water. ELISA detection shows that the effective release amount of dipotassium glycyrrhizate is ≥0.05 mg / g, demonstrating strong durability.

[0065] Application of multi-layer composite structures: The multi-layer composite structures described in this application are used for nursing towels, medical masks, or medical dressings;

[0066] When the weight of the multi-layer composite structure is 260-500 g / m², it is used as a care towel with a friction coefficient ≤0.25.

[0067] When the weight of the multi-layer composite structure is 150-250 g / m², when used as a medical mask, the 24-hour moisture permeability is ≥4500 g / m²; when used as a medical dressing, the liquid absorption rate is <3 s.

[0068] As can be seen from the above technical solution, the present invention possesses at least one of the following advantages and positive effects:

[0069] (1) The outer layer has a low-twist, fluffy structure and a pearl fiber microporous structure, which can quickly absorb exudate and reduce skin adhesion. The middle layer uses modal and pearl fiber, which has the function of absorbing and expanding liquid, increasing the liquid storage capacity by 40%. It also uses a double-plying method of the first warp and first weft yarns to guide the flow, and its vertical diffusion speed is as high as 5 cm / s. In this invention, the outer layer is set on both sides of the middle layer, which has a symmetrical structure and can be used in both directions to avoid misapplication. Through the multi-layer composite structure and the composite capsule fixed on the multi-layer composite structure, the modal in the middle layer absorbs moisture and expands to compress the bamboo fiber, thereby triggering the release of the composite capsule. The pearl fiber in the outer layer opens the skin channel, so that the multi-layer composite structure described in this application has a gradient slow-release synergistic effect.

[0070] This invention application addresses industry pain points through triple innovation in multi-layer composite structure, composite capsule formulation, and preparation process, and possesses significant market competitiveness.

[0071] This invention addresses industry pain points through a triple innovation in its multi-layered composite structure with rapid anti-inflammatory response, composite capsule formulation, and preparation process, resulting in significant market competitiveness. The composite capsules described in this invention exhibit a 5-minute release rate of ≥80% for the active ingredient dipotassium glycyrrhizate and a 24-hour release rate of ≤50% for the active ingredient panthenol B5, achieving a rapid response in acute anti-inflammatory treatment. The 5-minute release rate of dipotassium glycyrrhizate (≥80%) far exceeds industry standards, demonstrating outstanding technical efficacy.

[0072] (2) The modal in the middle layer absorbs moisture and expands, compressing the compact sciross, thereby triggering the release of ceramides; the weak alkaline ions in the pearl fiber neutralize the acidic environment of the sensitive skin, improving the absorption rate of the ingredients; while the compact sciross component has a micro-liquid storage cavity, which increases the specific surface area and loads ceramides, and also has a capillary effect, achieving linear release through the natural vertical ducts of bamboo fiber; at the same time, due to the honeycomb structure of the middle layer and the porosity ≥65%, the loading capacity of the composite capsule is increased by 30%.

[0073] (3) The pearl fibers in the outer layer release calcium and magnesium ions, open the skin ion channels, and promote the penetration of ceramides; the hemp short fibers inhibit bacteria and reduce component degradation, prolonging the sustained release time; the bamboo fiber is a high-density barrier, reducing the intrusion of external pollutants, protecting the activity of ceramides, and directing moisture. The hollow structure of the bamboo fiber guides the water to be transported from the inside to the outside, avoiding premature dissolution of components.

[0074] (4) The multi-layer composite structure is treated with a padding liquid-padding fixation process, and composite capsules are fixed on the surface of the multi-layer composite structure, forming the characteristics of sustained-release capsules, which are suitable for sensitive skin care towels, medical masks and medical dressings.

[0075] (5) This application creatively adopts a multi-layer composite structure and composite capsule technology. The middle layer of modal absorbs moisture and expands, compresses bamboo fiber and triggers the release of composite capsules, while the outer layer of pearl fiber opens the skin channel, realizing the synergistic optimization of the three functions of "absorption-liquid storage-release", which solves the technical problem of traditional dressings having a single function and uncontrollable drug release. Attached Figure Description

[0076] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0077] Figure 1 This is a schematic diagram of the multilayer composite structure described in this invention;

[0078] Figure 2 for Figure 1 A schematic diagram of the structure of the first warp and the first weft yarn in the intermediate layer;

[0079] Figure 3 for Figure 1 A schematic diagram of the structure of the second warp and the second weft yarn in the outer layer.

[0080] The annotations in the attached figures are explained as follows:

[0081] 1-Intermediate layer

[0082] 11-First warp yarn,

[0083] 12-First weft yarn,

[0084] 2-First outer layer,

[0085] 21-Second warp yarn,

[0086] 22 - Second weft yarn

[0087] 3-Second outer layer. Detailed Implementation

[0088] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0089] See appendix Figure 1 , 2 As shown in Figures 1 and 3, this application discloses a multi-layer composite structure with sustained-release function, which is a three-layer structure. Specifically, it includes a middle layer 1, which comprises a base fabric layer woven from a first warp yarn 11 and a first weft yarn 12; and a first outer layer 2 and a second outer layer 3 respectively provided on both sides of the middle layer 1. The first outer layer 2 and the second outer layer 3 have the same structure, wherein the first outer layer 2 comprises a surface fabric layer woven from a second warp yarn 21 and a second weft yarn 22. The first outer layer 2 and the second outer layer 3 both have a low-twist, fluffy structure and a pearl fiber microporous structure, which can quickly absorb exudate and reduce skin adhesion. The middle layer 1 uses modal and pearl fiber, which has the function of absorbing and expanding liquid volume, increasing the liquid storage capacity by 40%, and adopts a double-ply woven first warp yarn 11 and first weft yarn 12 for diffusing, with a vertical diffusion speed of 5 cm / s. See Table 1 for details.

[0090] hierarchy Functional design Technical effect First outer layer Low-twist, fluffy structure, pearl fiber microporous structure Quickly absorbs exudate and reduces skin adhesion. Intermediate layer Modal, pearl fiber, double-stranded diffusing agent Liquid storage capacity increased by 40%, vertical diffusion velocity increased by 5 cm / s Second outer layer Low-twist, fluffy structure, pearl fiber microporous structure Quickly absorbs exudate and reduces skin adhesion.

[0091] Table 1. Synergistic effect of intermediate layer, first outer layer and second outer layer in achieving gradient sustained release of active ingredients.

[0092] The first warp yarn 11 is a 40-count blended yarn containing 55% cotton, 30% modal, and 15% pearl fiber. The first weft yarn 12 is a 40-count compact Siro-spun yarn containing 50% bamboo fiber. The first warp yarn and the first weft yarn 12 are plied in a 1:1 ratio and are plied using a double-ply method. The intermediate layer 1 uses the first warp yarn and the first weft yarn to form a highly conductive slow-release layer with a vertical diffusion speed ≥5 cm / s. The pearl fiber in the first warp yarn and the bamboo fiber in the first weft yarn form a hydrophilic and energy-storing dual-grid channel, increasing the active ingredient carrying capacity by 30%. The second warp yarn 21 is a 32-count loose low-twist yarn containing 15% pearl fiber, 10% hemp staple fiber, 55% bamboo fiber, and 20% cotton. The second weft yarn is a 40-count compact Siro-spun yarn containing 50% bamboo fiber. The second warp yarn 21 and the second weft yarn are plied in a 1:1 ratio and are plied using a Z-twist method. Among them, pearl fiber, as a raw material for the yarn, can further improve the comfort of the product and enhance the skin protection effect. The pearl fiber is soft and skin-friendly and beneficial to the nutrition of human skin. The hemp staple fiber and cotton fiber, as raw materials for the yarn, can improve the yarn evenness. As described above, the second warp yarn and the second weft yarn constitute the tactile optimization layer of the product of this application.

[0093] This invention discloses a method for preparing a multilayer composite structure with sustained-release function, comprising:

[0094] A multi-layer composite structure was prepared using a double-sided terry knitting machine, with a spacing number of 22.

[0095] The first warp yarn 11 and the first weft yarn 12 are woven into an intermediate layer 1, which has a honeycomb structure, a porosity ≥65%, and a basis weight of 150g / m². 2 ;

[0096] On both sides of the intermediate layer 1, the second warp yarn 21 and the second weft yarn 22 are woven into an outer layer with a double-sided loop structure; the intermediate layer and the outer layer with the double-sided loop structure constitute a multi-layer composite structure. The second warp yarn contains hemp short fibers and bamboo fibers; the hemp short fibers are treated with a combination of pectinase and xylanase, and the bamboo fibers are modified by plasma.

[0097] In this application, the second warp yarn 21 contains hemp staple fiber and bamboo fiber. During preparation, the hemp staple fiber is treated with a combination of pectinase and xylanase, and the bamboo fiber is modified by plasma. Specifically, the pectinase content is 5 U / g, the xylanase content is 3 U / g, the temperature of the combination treatment is 50°C, and the treatment time is 120 minutes; while the bamboo fiber is treated with helium plasma, the vacuum degree required for the helium plasma environment is 10 Pa, and the treatment time is 90 seconds.

[0098] As is well known, plasma is an electrically neutral aggregate composed of ions, electrons, and neutral particles. During plasma surface treatment, when plasma collides with a material surface, it transfers its energy to the molecules and atoms on the surface, thus generating a series of physical and chemical reactions. Injecting particles or gases into the material surface can also induce collisions, scattering, excitation, rearrangement, isomerization, defects, crystallization, and amorphization, thereby altering the surface properties of the material.

[0099] In this application, the multi-layer composite structure is simultaneously treated by a single impregnation and fixation process with impregnation liquid, and composite capsules are fixed in both the interior and surface of the multi-layer composite structure, ensuring that the composite capsules penetrate into the middle layer.

[0100] The impregnation solution comprises, by weight, 10% composite capsules, 0.5% penetrant, 3% binder, pH adjuster, and deionized water;

[0101] The composite capsule is used for sustained release of the active ingredient, i.e., it has a sustained-release function; the penetrant promotes the penetration of the composite capsule into the intermediate layer; the adhesive is used to fix the composite capsule, fixing it in the heat-resistant ethyl cellulose coating layer; the pH adjuster is used to maintain the stability of the ceramide, and the pH is adjusted to 5.5 by using acetic acid; and the deionized water is a solvent, serving as a carrier in the above-mentioned padding solution. Further, the adhesive is preferably a modified polyacrylate, which is soft and washable.

[0102] The single-stage impregnation and fixation process of the impregnation solution includes:

[0103] (1) The multi-layer composite structure is desized and refined to ensure its hydrophilicity and capillary effect >10cm / min;

[0104] (2) During the immersion rolling process, after one immersion and one rolling, the roll residue rate is 80%, the temperature is 40℃, and the pressure is 0.3MPa, to ensure that the immersion liquid penetrates the multi-layer composite structure.

[0105] (3) Pre-drying: Dry with hot air at 80℃ for 2 minutes to fix the adhesive;

[0106] (4) Baking: Drying at 110℃ for 90 seconds to ensure that the outer wall of the composite capsule is firmly bonded to the heat-resistant coating layer (EC layer) of ethyl cellulose.

[0107] (5) After the above treatment, wash away the unfixed components on the multilayer composite structure with cold water, and finally dry the multilayer composite structure.

[0108] Furthermore, during the impregnation and rolling process, the rolling operation is achieved through rollers, the pressure gradient of which is controlled between 0.1 MPa and 0.3 MPa, and the pressure is applied in segments; after pre-drying, the material is treated with low-temperature plasma in an N2 atmosphere at a power of 50 W for 2 minutes.

[0109] In this invention, it is important to note that the middle layer of the multi-layer composite structure requires cross-sectional slicing to test the uniformity of capsule distribution. When combined with the composite capsule, the multi-layer composite structure produced by this invention possesses a sustained-release function, combining skin care, wound repair, and sustained-release capabilities; particularly the sustained-release function, which meets the needs of high-end medical dressings.

[0110] The heat-resistant ethyl cellulose coating layer contains mesoporous silica, which adsorbs ceramides and delays their release; the release rate is >90% after 72 hours. Mesoporous silica is an inorganic material with a highly ordered pore structure, typically classified into micropores and mesopores. Micropores have a pore size range of less than 2 nanometers, while mesopores range from 2 to 50 nanometers. This material has a large specific surface area and pore volume, making it an ideal catalyst and adsorbent. The mesoporous silica in this invention has a pore size of 2 nanometers. The composite capsules are encapsulated in an ethyl cellulose heat-resistant layer containing mesoporous silica (2 nm pore size), achieving a cumulative release rate of >90% after 72 hours.

[0111] The composite wall material composed of the ethyl cellulose heat-resistant coating layer and mesoporous silica described above has a heat resistance of 110℃.

[0112] The composite capsules include composite capsule one and composite capsule two; composite capsule one is prepared by composite capsule emulsion one; the preparation process of composite capsule emulsion one includes: dissolving ceramide in ethanol to form solution one, dissolving panthenol B5 in water to form solution two, and dispersing colloidal oats in deionized water to form solution three.

[0113] The above solutions 1, 2, and 3 are mixed, and natural polysaccharides and emulsifiers are added. After homogenization and emulsification in a mixer, a compound capsule emulsion is obtained.

[0114] The second composite capsule is prepared by the second composite capsule emulsion; the preparation process of the second composite capsule emulsion includes: dissolving dipotassium glycyrrhizate in ethanol to form solution four, and dissolving panthenol B5 in water to form solution two;

[0115] Solution 4 and Solution 2 are mixed, and natural polysaccharides and emulsifiers are added. After homogenization and emulsification in a mixer, composite capsule emulsion 2 is obtained. The temperature of the ethanol is 60°C, the natural polysaccharide includes, but is not limited to, sodium alginate, and the emulsifier includes, but is not limited to, lecithin. During the homogenization and emulsification process, the mixer speed is 10,000 rpm, and the time is 15 minutes.

[0116] The composite capsule emulsion was added to a gelatin solution with a pH of 4.0. After stirring, a gum arabic solution was added. The gelatin solution and the gum arabic solution formed a composite colloid, and its pH was adjusted to 4.5.

[0117] After stirring, the composite colloid forms the capsule wall of composite capsule one and composite capsule two. Composite capsule one contains ceramide, panthenol B5 and colloidal oats, while composite capsule two contains dipotassium glycyrrhizate and panthenol B5.

[0118] After solidification, filtration, freezing and drying, tiny powdery composite capsules one and two, i.e. microcapsules, are obtained.

[0119] The particle size of the prepared composite capsules is 1μm to 1.5μm, and the particle size of the second composite capsule is 1μm to 3.0μm. The composite capsules contain ceramide, panthenol B5, and colloidal oats, all of which are active substances. The mass ratio of these three active substances to the solvent is: ceramide 5%, panthenol B5 15%, colloidal oats 10%, and solvent 70%. The ratio of ceramide, panthenol B5, and colloidal oats is 1:3:2. In the second composite capsule, the mass ratio of the two active substances to the solvent is: dipotassium glycyrrhizate 0.5%, panthenol B5 15%, and solvent 84.5%.

[0120] The response release mechanism of the composite capsule in the multilayer composite structure of this invention is as follows: upon contact with the body's tissue fluid, colloidal oats are released first, providing anti-inflammatory sustained release within approximately 5 minutes; when humidity > 70%, panthenol B5 is continuously released, providing moisturizing and repairing effects; and ceramide is continuously released over 24 hours, providing barrier repair effects. The multilayer composite structure of this application, after 50 washes (according to GB / T 3921-2008, 40℃ neutral detergent, wash-dry cycle counts as one cycle), retains ≥90% of the effective release rate of ceramide (1.22mg / g → 1.10mg / g), with a friction coefficient fluctuation ≤ 0.03, still maintains its performance.

[0121] Application of a multilayer composite structure with sustained-release function, the multilayer composite structure described in this application is used for care towels, medical masks or medical dressings;

[0122] When the weight of the multi-layer composite structure is 260-500 g / m², it is used as a care towel with a friction coefficient ≤0.25.

[0123] When the weight of the multi-layer composite structure is 180-250 g / m², when used as a medical mask, the 24-hour moisture permeability is ≥4500 g / m²; when used as a medical dressing, the liquid absorption rate is <3 s.

[0124] The medical dressings prepared using the multilayer composite structure described in this application were subjected to performance testing according to the pharmaceutical industry standard YY / T0473-2004. The test data are shown in Table 2.

[0125] Test Project Test Results Industry standard requirements Liquid adsorption capacity <![CDATA[9.2±0.3g / 100cm 2 ]]> <![CDATA[≥5g / 100cm 2 ]]> Ceramide release (24h) <![CDATA[0.85mg / cm 2 ]]> No standard Skin sensitization Level 0 (No Stimulation) ≤ Level 1

[0126] Table 2 Performance Test Table of Medical Dressings Prepared with Multilayer Composite Structures

[0127] It is evident that the medical dressing prepared using the multi-layer composite structure of this application has a liquid adsorption capacity far exceeding the industry standard, and the ceramide release amount is 0.85 mg / cm2 in 24 hours, truly achieving skin-friendly and non-irritating properties.

[0128] In this invention, the outer layer has a low-twist, fluffy structure and a pearl fiber microporous structure, enabling rapid absorption of exudate and reducing skin adhesion. The middle layer, made of modal and pearl fiber, has liquid absorption and expansion functions, increasing liquid storage capacity by 40%. It also employs a double-ply weft yarn (first warp and first weft) for flow guidance, achieving a vertical diffusion speed of 5 cm / s. The symmetrical structure of the outer layer, with the middle layer on both sides, allows for bidirectional use and prevents accidental application. The modal in the middle layer absorbs moisture, expands, and compresses the tightly bound sirospun fabric, triggering ceramide release. The weakly alkaline ions in the pearl fiber neutralize the acidic environment of sensitive skin, improving component absorption. The tightly bound sirospun components have micro-liquid storage chambers, increasing the surface area for ceramide loading and exhibiting a capillary effect, achieving linear release through the natural vertical ducts of bamboo fiber. The pearl fibers in the outer layer release calcium and magnesium ions, opening skin ion channels and promoting ceramide penetration. The hemp short fibers inhibit bacteria, reduce component degradation, and prolong the sustained-release effect. The bamboo fiber acts as a high-density barrier, reducing the intrusion of external pollutants, protecting ceramide activity, and guiding moisture. The hollow structure of the bamboo fiber guides moisture from the inside to the outside, preventing premature dissolution of components. The multi-layered composite structure undergoes a padding-padding fixation process, resulting in composite capsules fixed to the surface of the multi-layered composite structure, forming characteristics with sustained-release capsule function, suitable for sensitive skin care towels, medical masks, and medical dressings. This application creatively employs a multi-layered composite structure and microcapsule technology to achieve synergistic optimization of the "absorption-liquid storage-release" triple function, solving the technical problems of traditional dressings having single function and uncontrollable drug release.

[0129] The application of the multi-layer composite structure described in this application is as follows: the multi-layer composite structure is used for nursing towels, medical masks, or medical dressings; when the basis weight of the multi-layer composite structure is 260-500 g / m², it is used as a nursing towel; when the basis weight of the multi-layer composite structure is 150-250 g / m², it is used as a medical mask or medical dressing.

[0130] It should be understood that the application of this invention is not limited to the detailed structure and arrangement of the components presented herein. The invention can have other embodiments and can be implemented and performed in various ways. The foregoing variations and modifications fall within the scope of this invention. It should be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or drawings. The embodiments described herein illustrate the best known mode for carrying out the invention and will enable those skilled in the art to utilize the invention.

Claims

1. A multilayer composite structure with sustained-release function, characterized in that, It includes at least one intermediate layer, which includes a base fabric layer woven from a first warp yarn and a first weft yarn; And at least one outer layer is provided on both sides of the intermediate layer, the outer layer comprising a surface fabric layer woven from a second warp yarn and a second weft yarn; In this multi-layered composite structure, composite capsules are fixed inside and on the surface of the middle and outer layers, enabling the middle and outer layers to synergistically achieve gradient slow release of active ingredients. The gradient slow release is achieved through rapid liquid absorption by the outer layer, liquid storage expansion by the middle layer, and phased release of the composite capsules in response to tissue fluid humidity.

2. The multilayer composite structure according to claim 1, characterized in that, The first warp yarn is a 32-60 count blended yarn containing 35%-55% cotton, 20%-40% modal, and 15%-35% pearl fiber; the first weft yarn is a 32-60 count compact Siro spun yarn containing 50%-100% bamboo fiber. The first warp and the first weft are twisted in a 1:1 ratio and are twisted using a double-thread twisting method; the intermediate layer uses the first warp and the first weft to form a highly conductive slow-release layer with a vertical diffusion speed ≥5 cm / s; the pearl fiber in the first warp and the bamboo fiber in the first weft form a hydrophilic and energy-storing dual-grid channel. The pearl fiber is a viscose fiber containing ≥90% calcium carbonate, with a fineness of 1.0 to 1.5 dtex.

3. The multilayer composite structure according to claim 1, characterized in that, The second warp yarn is a 32-60 count loose low twist yarn, and contains 8%-15% pearl fiber, 5%-15% hemp staple fiber, 55% bamboo fiber and 20% cotton. The second weft yarn is a 32-60 count compact spun yarn, and contains 50%-100% bamboo fiber. The second warp yarn and the second weft yarn are twisted in a 1:1 ratio and the twist direction is Z-twist. Pearl fiber, as a raw material for yarn, can further improve the comfort of the product and enhance the skin protection effect. The pearl fiber is soft and skin-friendly and beneficial to the nutrition of human skin. The hemp staple fiber and cotton fiber, as raw materials for yarn, can improve the yarn evenness. Hemp staple fiber, flax, and ramie can be substituted for each other after the same enzyme treatment (pectinase 5U / g + xylanase 3U / g). The pearl fiber is a viscose fiber containing ≥90% calcium carbonate and has a fineness of 1.0~1.5dtex. The second warp yarn and the second weft yarn constitute the tactile optimization layer of the multi-layer composite structure of this application.

4. A method for preparing a multilayer composite structure with sustained-release function, characterized in that, At least including: A multi-layer composite structure is prepared using a double-sided terry loom. The first warp and first weft yarns are woven into an intermediate layer, which has a honeycomb structure, a porosity ≥65%, and a basis weight of 60 g / m². 2 ~220g / m 2 ; On both sides of the middle layer, the second warp yarn and the second weft yarn are woven into an outer layer with a double-sided loop structure; The middle layer and the outer layer with a double-sided terry loop structure constitute a multi-layer composite structure; The second warp yarn contains hemp staple fiber and bamboo fiber; wherein, the hemp staple fiber is treated with pectinase and xylanase, and the bamboo fiber is modified by plasma; the pectinase content is 5U / g, the xylanase content is 3U / g, the composite treatment temperature is 50℃, and the treatment time is 120 minutes; the bamboo fiber is treated with helium plasma, the vacuum degree required for helium plasma treatment is 10Pa, and the treatment time is 90 seconds.

5. The method for preparing a multilayer composite structure with sustained-release function according to claim 4, characterized in that, The multi-layer composite structure is simultaneously treated by a single impregnation and fixation process with impregnation liquid, and composite capsules are fixed in both the interior and surface of the multi-layer composite structure, ensuring that the composite capsules penetrate into the middle layer. The impregnation solution comprises, by weight, 8%–12% composite capsules, 0.5% penetrant, 3% binder, acetic acid (pH adjuster), and deionized water; The composite capsule is used for sustained release of active ingredients, i.e., it has a sustained release function; the penetrant promotes the penetration of the composite capsule into the intermediate layer; the adhesive is used to fix the composite capsule, fixing it in the heat-resistant coating layer of ethyl cellulose; the pH adjuster is used to maintain the stability of ceramide, and the pH is adjusted to 5.5 by the acetic acid pH adjuster; and the deionized water is a solvent, serving as a carrier in the above-mentioned impregnation liquid; Because the middle and outer layers of the multi-layered composite structure are all fixed with composite capsules, the middle and outer layers work together to achieve gradient sustained release of active ingredients and rapid anti-inflammatory response. The gradient sustained release is achieved through rapid liquid absorption by the outer layer, liquid storage expansion by the middle layer, and phased release by the composite capsule in response to tissue fluid moisture. The rapid anti-inflammatory response is characterized by a release of ≥85% of dipotassium glycyrrhizate in 5 minutes.

6. The method for preparing a multilayer composite structure with sustained-release function according to claim 5, characterized in that, The single-stage impregnation and fixation process of the impregnation solution includes: (1) The multi-layer composite structure is desized and refined to ensure its hydrophilicity and capillary effect >10cm / min; (2) During the impregnation and rolling process, after one impregnation and one rolling, the roll residue rate is 80%, the temperature is 40℃, and the pressure is 0.3MPa, ensuring that the impregnation liquid penetrates the multi-layer composite structure; during the impregnation and rolling process, the impregnation pressure gradient gradually increases from 0.1MPa to 0.3MPa, so that the composite capsule enters the intermediate layer. (3) Pre-drying: Dry with hot air at 80℃ for 2 minutes to fix the adhesive; (4) Baking: Drying at 110℃ for 90 seconds to ensure that the outer wall of the composite capsule is firmly bonded to the heat-resistant coating of ethyl cellulose. (5) After the above treatment, wash away the unfixed components on the multilayer composite structure with cold water, and finally dry the multilayer composite structure.

7. The method for preparing a multilayer composite structure with sustained-release function according to claim 6, characterized in that, The ethyl cellulose heat-resistant coating contains mesoporous silica, which adsorbs ceramides and delays their release; the release rate is >90% after 72 hours; the pore size of the mesoporous silica is 2 nanometers.

8. The method for preparing a multilayer composite structure with sustained-release function according to claim 5, characterized in that, The composite capsules are prepared by a composite capsule emulsion; the composite capsules include composite capsule one and / or composite capsule two. The composite capsule one is prepared by composite capsule emulsion one; the preparation process of the composite capsule emulsion one includes: dissolving ceramide in ethanol to form solution one, dissolving panthenol B5 in water to form solution two, and dispersing colloidal oats in deionized water to form solution three. Mix the above solutions 1, 2, and 3, add natural polysaccharides and emulsifiers, and homogenize and emulsify in a mixer to obtain compound capsule emulsion 1; The second composite capsule is prepared by the second composite capsule emulsion; the preparation process of the second composite capsule emulsion includes: dissolving dipotassium glycyrrhizate in ethanol to form solution four, and dissolving panthenol B5 in water to form solution two; Mix the above solutions four and two, add natural polysaccharides and emulsifiers, and homogenize and emulsify in a mixer to obtain compound capsule emulsion two; The composite capsule emulsion was added to a gelatin solution with a pH of 4.

0. After stirring, a gum arabic solution was added. The gelatin solution and the gum arabic solution formed a composite colloid, and its pH was adjusted to 4.

5. After stirring, the composite colloid forms the capsule wall of composite capsule one and composite capsule two. Composite capsule one contains ceramide, panthenol B5 and colloidal oats, while composite capsule two contains dipotassium glycyrrhizate and panthenol B5. After solidification, filtration, freezing and drying, tiny powdery composite capsules one and two, i.e. microcapsules, are obtained. The composite capsule contains ceramide, panthenol B5, and colloidal oats, all of which are active substances. The three active substances and the solvent are in the following proportions by mass: ceramide 5%, panthenol B5 15%, colloidal oats 10%, and solvent 70%. The ratio of ceramide, panthenol B5, and colloidal oats is 1:3:

2. The second composite capsule contains dipotassium glycyrrhizate and panthenol B5, both of which are active substances. The mass fractions of the two active substances and the solvent are as follows: dipotassium glycyrrhizate 0.5%, panthenol B5 15%, and solvent 84.5%.

9. The method for preparing a multilayer composite structure with sustained-release function according to claim 8, characterized in that, The response release mechanism of the compound capsule is as follows: when the multi-layered composite structure comes into contact with the body's tissue fluid, the colloidal oats are released first, and the anti-inflammatory sustained release occurs within about 5 minutes; When humidity is greater than 70%, panthenol B5 is continuously released, which has moisturizing and repairing effects; Ceramides are continuously released over 24 hours and have a barrier repair effect. In the multilayer composite structure described in this application, the performance can still be retained after 50 water washes, and the effective release amount of the ceramide is 1.22 mg / g; The response release mechanism of the composite capsule II is as follows: the outer layer of the multi-layer composite structure absorbs the tissue fluid secreted by the human body, the tissue fluid dissolves the capsule wall of the composite capsule, and the release rate of dipotassium glycyrrhizate reaches 85% within 5 minutes, realizing the rapid release of anti-inflammatory components within 5 minutes of contact with tissue fluid, while panthenol B5 is continuously released, which has a moisturizing and repairing effect; in the multi-layer composite structure described in this application, the performance can still be retained after 50 washes with water. The effective release amount of dipotassium glycyrrhizate is ≥0.05mg / g as determined by ELISA, indicating strong durability.

10. An application of a multilayer composite structure with sustained-release function, characterized in that, The multi-layer composite structure described in this application is used for care towels, medical masks, or medical dressings; When the weight of the multi-layer composite structure is 260-500 g / m², it is used as a care towel with a friction coefficient ≤0.

25. When the weight of the multi-layer composite structure is 150-250 g / m², when used as a medical mask, the 24-hour moisture permeability is ≥4500 g / m²; when used as a medical dressing, the liquid absorption rate is <3 s.

Images