Self-adapting pore-adjusting fluorine-free fabric finishing agent based on humidity-responsive microspheres, and preparation method and application thereof

Abstract

The application discloses a self-adaptive pore-adjusting fluorine-free fabric finishing agent based on humidity response microspheres and a preparation method and application thereof. The fluorine-free fabric finishing agent is a water-based dispersion liquid, and the water-based dispersion liquid comprises the following raw materials: humidity response type intelligent pore-forming microspheres, an adhesive and a low surface energy modifier. The humidity response type intelligent pore-forming microspheres comprise a core and a shell. The core comprises an interpenetrating network (IPN) hydrogel, and the shell comprises a rigid mesoporous material. The rigid mesoporous material has a reactive functional group on the surface. The finishing agent of the application can construct an intelligent coating system of'stimulus response-structure deformation-selective permeation', so that the fabric can dynamically and reversibly adjust the internal porosity according to the change of environmental humidity, thereby realizing the intelligent balance of high waterproofness and high moisture permeability.

Description

Technical Field

[0001] This invention relates to the field of functional textile finishing technology, specifically to an adaptive pore-regulating fluorine-free fabric finishing agent based on humidity-responsive microspheres, its preparation method, and its application. Background Technology

[0002] With the development of outdoor sports and special protective equipment, the demand for "breathable" functional textiles that combine excellent waterproofing and high breathability is increasing. Traditional fluorinated waterproofing agents (such as PFAS) are being gradually restricted globally due to their environmental persistence and bioaccumulation issues. Current fluorine-free alternatives are mainly based on constructing superhydrophobic surfaces using materials such as silicone and polyurethane. While these can achieve a certain level of waterproofing, they generally face two major technical bottlenecks: First, waterproofing and breathability are mutually restrictive. To achieve high hydrostatic pressure resistance, the coating needs a dense and complete structure, which inevitably blocks water vapor transport channels, leading to sweat accumulation and affecting wearing comfort. Second, the function is static and rigid. Once formed, the existing coating's microstructure remains fixed and cannot respond to the microenvironmental changes caused by heat production and sweating during the transition from a static to an active state.

[0003] In recent years, although some studies have attempted to introduce temperature-sensitive polymers (such as PNIPAM) into textiles, these efforts have mostly been limited to the reversible switching of surface wettability, failing to achieve dynamic control over the internal pore structure of the coating. Furthermore, the related synthetic routes are complex, making industrialization difficult. Therefore, developing a smart textile finishing agent based on mature industrial raw materials, capable of large-scale preparation, and possessing "breathable on demand" functionality has become an urgent need in the industry. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a fluorine-free fabric finishing agent, which is based on a compound of humidity-responsive microspheres and commercially available polymers. By constructing a smart coating system of "stimulus response-structural deformation-selective permeability", the fabric can dynamically and reversibly adjust its internal porosity according to changes in environmental humidity, thereby achieving an intelligent balance between high water resistance and high moisture permeability.

[0005] The present invention also proposes a method for preparing the above-mentioned fluorine-free fabric finishing agent.

[0006] The present invention also proposes the application of the above-mentioned fluorine-free fabric finishing agent.

[0007] According to one aspect of the present invention, a fluorine-free fabric finishing agent is provided, wherein the fluorine-free fabric finishing agent is an aqueous dispersion comprising the following raw materials: humidity-responsive smart pore-forming microspheres, a binder, and a low surface energy modifier, wherein the humidity-responsive smart pore-forming microspheres comprise a core and a shell, wherein the core comprises an interpenetrating network (IPN) hydrogel, and the shell comprises a rigid mesoporous material, the surface of which has reactive functional groups.

[0008] The finishing agent of this invention constructs a smart coating system of "stimulus response-structural deformation-selective permeability," enabling fabrics to dynamically and reversibly adjust their internal porosity according to changes in ambient humidity, thereby achieving a smart balance between high water resistance and high moisture permeability. Specifically, the humidity-responsive smart porous microspheres possess the dual functions of sensing ambient humidity and driving the coating structure; their core is composed of an interpenetrating hydrogel network with high water absorption and high volume expansion rate, responsible for responding to humidity changes and generating deformation driving force; the outer shell is a rigid mesoporous material with nanopores and reactive functional groups, providing stable mechanical support and chemical reaction sites, while its pore structure facilitates the rapid entry and exit of moisture into and out of the core. The adhesive, as the framework of the coating, imparts mechanical support, flexibility, and adhesion to the fabric; the low surface energy modifier provides and maintains the overall superhydrophobicity of the coating.

[0009] According to some embodiments of the present invention, the raw materials for preparing the interpenetrating network hydrogel satisfy at least one of the following characteristics: 1) having hydrophilic groups; 2) having crosslinkability; 3) having humidity volume responsiveness.

[0010] According to some embodiments of the present invention, the interpenetrating network hydrogel, based on dry weight, has an equilibrium water absorption rate of over 80% at 25°C and 95% relative humidity, and its volume swelling rate can reach over 100% when the relative humidity increases from 50% to 95%. The core is composed of an interpenetrating network hydrogel with specific hygroscopic and volume expansion properties, such as polyvinyl alcohol / polyacrylic acid hydrogel, which is responsible for responding to humidity and generating deformation driving force.

[0011] According to some embodiments of the present invention, the raw materials for preparing the interpenetrating network hydrogel include monomeric compounds having hydrophilic groups.

[0012] According to some embodiments of the present invention, the hydrophilic group includes at least one of hydroxyl (-OH), carboxyl (-COOH), amide (-CONH2), or sulfonic acid (-SO3H).

[0013] According to some embodiments of the present invention, the crosslinkability includes chemical or physical crosslinking. Chemical or physical crosslinking forms a stable three-dimensional network structure to ensure the structural integrity of the hydrogel during repeated swelling-shrinkage cycles; specifically, this can be achieved by adding a crosslinking agent (such as N,N'-methylenebisacrylamide, glutaraldehyde, epichlorohydrin, etc.) or by utilizing physical interactions such as ionic crosslinking and hydrogen bonding.

[0014] According to some embodiments of the present invention, the humidity volume response means that the hydrogel network constructed from the selected raw materials can undergo reversible volume expansion and contraction when the humidity changes, and the volume swelling rate can reach more than 100%.

[0015] According to some embodiments of the present invention, the volume swelling ratio is 120-200%.

[0016] According to some embodiments of the present invention, the volume swelling ratio is 130-170%.

[0017] According to some embodiments of the present invention, the raw materials used in the preparation of the interpenetrating network hydrogel also meet the requirements of biocompatibility and environmental friendliness. Preferably, non-toxic, biodegradable, or environmentally friendly raw materials are used to meet the requirements for safety and environmental protection in textile wear.

[0018] According to some embodiments of the present invention, the interpenetrating network hydrogel comprises at least one of the following components: polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyacrylamide (PAM), poly N-vinylpyrrolidone (PVP), polyethylene glycol (PEG), polymethacrylic acid (PMAA), sodium alginate, and sodium carboxymethyl cellulose.

[0019] According to some embodiments of the present invention, the interpenetrating network hydrogel includes polyvinyl alcohol / polyacrylic acid (PVA / PAA) hydrogel, polyvinyl alcohol / polyacrylamide (PVA / PAM) hydrogel, or polyacrylic acid / polyN-vinylpyrrolidone (PAA / PVP) hydrogel. Both PVA and PAM composite systems and PAA and PVP interpenetrating network systems can achieve similar high moisture absorption and high expansion properties.

[0020] According to some embodiments of the present invention, the reactive functional group includes at least one selected from amino, hydroxyl, carboxyl, epoxy, and mercapto groups. The surface of the rigid mesoporous material has functionalizable reactive functional groups, enabling the introduction of active functional groups that react with the adhesive system.

[0021] According to some embodiments of the present invention, the rigid mesoporous material includes at least one of inorganic mesoporous materials, organic / inorganic hybrid mesoporous materials, polymer-based mesoporous materials, or carbon-based mesoporous materials.

[0022] According to some embodiments of the present invention, the inorganic mesoporous material includes at least one of mesoporous alumina, mesoporous silica, mesoporous titanium dioxide, or mesoporous zirconium oxide.

[0023] According to some embodiments of the present invention, the organic / inorganic hybrid mesoporous material includes mesoporous organosilicon or mesoporous metal-organic framework materials.

[0024] According to some embodiments of the present invention, the polymer-based mesoporous material includes at least one of mesoporous phenolic resin or mesoporous polydopamine.

[0025] According to some embodiments of the present invention, the carbon-based mesoporous material comprises mesoporous carbon.

[0026] According to some embodiments of the present invention, the rigid mesoporous material satisfies at least one of the following structural characteristics: 1) Young's modulus not less than 1 GPa; 2) pore size of 2~50 nm; 3) specific surface area not less than 200 m². 2 / g. The rigid mesoporous material has rigid support capabilities and a mesoporous channel structure.

[0027] According to some embodiments of the present invention, the rigid mesoporous material has a pore size of 2-10 nm. This pore size range ensures rapid water passage to trigger a core response while maintaining the mechanical integrity of the shell structure during repeated swelling-contraction cycles, and can effectively anchor functional load materials.

[0028] According to some embodiments of the present invention, the pore size of the rigid mesoporous material is 2~5 nm.

[0029] According to some embodiments of the present invention, the rigid mesoporous material also has at least one of the following properties: 1) chemical stability in the finishing and application environment; 2) good interfacial compatibility with the core material.

[0030] According to some embodiments of the present invention, the rigid mesoporous material comprises aminated mesoporous silica. Using rigid mesoporous materials such as aminated mesoporous silica can provide stable mechanical support and chemical reaction sites, while its pores facilitate the rapid entry and exit of moisture into and from the core.

[0031] According to some embodiments of the present invention, the rigid mesoporous material is further loaded with an antibacterial agent, such as Ag. + Furthermore, 1.5% silver ions can be loaded into the outer shell of the microspheres via ion exchange.

[0032] According to some embodiments of the present invention, the adhesive comprises the following raw materials: film-forming resin, crosslinking agent I, and catalyst, and optionally, adhesion promoter.

[0033] According to some embodiments of the present invention, the film-forming resin comprises epoxy-modified waterborne polyurethane and reactive organosilicon. The film-forming resin is obtained by compounding epoxy-modified waterborne polyurethane and reactive organosilicon, which synergistically provide strength, flexibility, and reactivity.

[0034] According to some embodiments of the present invention, the mass ratio of the epoxy-modified waterborne polyurethane to the reactive organosilicon is 11~19:1~8.

[0035] According to some embodiments of the present invention, the mass ratio of the epoxy-modified waterborne polyurethane to the reactive organosilicon is 12~18:3~6 (which can be abbreviated as 4~6:1~2).

[0036] According to some embodiments of the present invention, the mass ratio of the epoxy-modified waterborne polyurethane to the reactive organosilicon is 15:4.

[0037] According to some embodiments of the present invention, the film-forming resin includes NeoRez. ® R-9620 and Silok ® 8110.

[0038] According to some embodiments of the present invention, the crosslinking agent I includes an amino resin, such as hexamethoxymethyl melamine (HMMM), trade name Cymel® 303. When an amino resin is used as a crosslinking agent, it can covalently crosslink with the epoxy groups in the polyurethane, the amino groups of the microspheres, etc., during curing.

[0039] According to some embodiments of the present invention, the catalyst comprises a latent acid catalyst. For example, p-toluenesulfonic acid (p-TSA) releases acidity during baking, efficiently catalyzing the aforementioned crosslinking reaction.

[0040] According to some embodiments of the present invention, the adhesion promoter includes silane coupling agent KH-560 for enhancing adhesion to synthetic fibers.

[0041] According to some embodiments of the present invention, the adhesive, based on solids, comprises the following raw materials in parts by weight: 5-15 parts film-forming resin, 1-5 parts crosslinking agent, 0.1-0.5 parts catalyst and 0-2 parts adhesion promoter.

[0042] According to some embodiments of the present invention, the low surface energy modifier comprises long-chain alkylsiloxanes.

[0043] According to some embodiments of the present invention, the low surface energy modifier comprises octadecyltrimethoxysilane.

[0044] According to some embodiments of the present invention, the mass ratio of the humidity-responsive smart pore-forming microspheres, the adhesive, and the low surface energy modifier is 2~8:20~43:0.5~3.

[0045] According to some embodiments of the present invention, the mass ratio of the humidity-responsive smart pore-forming microspheres, the adhesive, and the low surface energy modifier is 3~7:20~43:0.5~3. According to some embodiments of the present invention, the mass percentage of the humidity-responsive smart pore-forming microspheres in the fluorine-free fabric finishing agent is 2%~8%.

[0046] According to some embodiments of the present invention, the moisture-responsive smart pore-forming microspheres in the fluorine-free fabric finishing agent account for 3% to 7% by mass.

[0047] According to some embodiments of the present invention, the adhesive in the fluorine-free fabric finishing agent accounts for 20-43% by mass.

[0048] According to some embodiments of the present invention, the adhesive in the fluorine-free fabric finishing agent accounts for 21-42% by mass.

[0049] According to some embodiments of the present invention, the mass percentage of the low surface energy modifier in the fluorine-free fabric finishing agent is 0.5-3%.

[0050] According to some embodiments of the present invention, the mass percentage of the low surface energy modifier in the fluorine-free fabric finishing agent is 1-2%, such as approximately 1.5%.

[0051] According to another aspect of the present invention, a method for preparing the above-mentioned fluorine-free fabric finishing agent is provided, comprising the following steps: S1. Preparation of humidity-responsive smart porous microspheres: A hydrogel core is synthesized and dried. A mesoporous material layer is coated on the surface of the core by a sol-gel method in the presence of a template agent. Reactive functional groups are modified on the surface of the mesoporous material layer. S2. Mix the humidity-responsive smart pore-forming microspheres, adhesive, and low surface energy modifier obtained in step S1 with water to prepare an aqueous dispersion.

[0052] According to some embodiments of the present invention, the raw materials for preparing the hydrogel core in step S1 include a first polymer, a monomer compound of a second polymer, a crosslinking agent, and an initiator. The synthesis process of the hydrogel core includes the following steps: adding the monomer compound of the second polymer, crosslinking agent II, and initiator to a solution of the first polymer, reacting, and forming an interpenetrating network hydrogel.

[0053] According to some embodiments of the present invention, the mass ratio of the monomer compounds of the first polymer to the second polymer is 3~8:5~12.

[0054] According to some embodiments of the present invention, the synthesis process of the hydrogel core in step S1 includes the following steps: taking a polyvinyl alcohol solution, adding acrylic acid, crosslinking agent II and initiator, and reacting to form an interpenetrating network hydrogel.

[0055] According to some embodiments of the present invention, the reaction conditions for the synthesis of the hydrogel core in step S1 are 60~70℃ and the reaction time is 4~8h.

[0056] According to some embodiments of the present invention, the crosslinking agent II comprises N,N'-methyleneacrylamide.

[0057] According to some embodiments of the present invention, the amount of crosslinking agent II is 0.5% to 1.5% of the mass of the monomer compound.

[0058] According to some embodiments of the present invention, the template agent is a surfactant template agent, such as hexadecyltrimethylammonium bromide (CTAB).

[0059] According to another aspect of the invention, the application of the above-mentioned fluorine-free fabric finishing agent in the field of clothing is also provided.

[0060] According to some embodiments of the present invention, the clothing includes at least one of outdoor sportswear or special protective clothing.

[0061] According to another aspect of the invention, a fabric is also provided, the fabric comprising a body and a coating located on the surface of the body, the raw material for preparing the coating comprising the above-mentioned fluorine-free fabric finishing agent.

[0062] Compared with the prior art, the present invention has the following beneficial effects: (1) Adaptive function: For the first time, through the ingenious compounding of commercially available raw materials, the pore structure of the coating of commercial textiles is intelligently controlled, so that the fabric has the "breathing" ability similar to skin, fundamentally solving the static contradiction between waterproof and breathable.

[0063] (2) Excellent durability: The microspheres form covalent bonds with the adhesive through the reactive functional groups of the shell and are chemically anchored in the cross-linked network through covalent bonds, which solves the problem of easy detachment of functional particles in traditional coatings and significantly improves washability and wear resistance.

[0064] (3) Strong industrialization advantages: All core polymer raw materials are commercially available industrial products, and the finishing process (pad-baking) is fully compatible with existing textile processing production lines. There is no new equipment investment, and it is easy to promote on a large scale.

[0065] (4) Environmental friendliness and safety: The entire formulation system is fluorine-free and solvent-free, and uses water as a medium, which complies with global environmental regulations and green manufacturing trends.

[0066] (5) High performance designability: By adjusting the response threshold of the microspheres, the flexibility of the adhesive and the crosslinking density, a series of products suitable for different climate conditions and application scenarios can be customized and developed.

[0067] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0068] Figure 1 This is a SEM image of the microspheres prepared in Example 1 of the present invention.

[0069] Figure 2 These are optical microscope images of the microspheres prepared in Example 1 of the present invention, wherein (a) is taken with the eyepiece magnification of 10x and (b) is taken with the objective lens magnification of 16x. Detailed Implementation

[0070] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the same parameter value is the same in all embodiments. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0071] In the description of this invention, references to terms such as "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] In the description of this invention, the use of terms such as first, second, or I, II is for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0073] In the description of this invention, equilibrium water absorption rate refers to the percentage of the mass of water absorbed by the material relative to its dry weight when the material reaches moisture absorption equilibrium under specific temperature and humidity conditions.

[0074] In the description of this invention, volume swelling rate refers to the percentage change in volume of a material under specific humidity conditions.

[0075] The fluorine-free fabric finishing agent provided by this invention is a water-based dispersion that can achieve adaptive pore adjustment.

[0076] Its key lies in including the following three functional components: 1. Humidity-responsive intelligent porous microspheres (H-SRM): serving as a sensor of environmental humidity and a driver of changes in coating structure.

[0077] 2. Flexible cross-linked network adhesive system: As the skeleton of the coating, it provides mechanical support, flexibility and adhesion to the fabric.

[0078] 3. Low surface energy modifiers: provide and maintain the overall superhydrophobicity of the coating.

[0079] The specific composition and preparation process of the core component H-SRM are as follows: Structure and Function: The microsphere has a core-shell structure. The core is composed of an interpenetrating network (IPN) hydrogel with high hygroscopicity and high volume expansion rate, such as polyvinyl alcohol / polyacrylic acid (PVA / PAA) hydrogel, which is responsible for responding to humidity and generating deformation driving force. Specifically, the hydrogel core has an equilibrium water absorption rate of ≥80% (on a dry basis) at 25°C and 95% relative humidity, and its volume expansion rate is ≥100%, preferably 120%-200%, when the relative humidity increases from 50% to 95%.

[0080] The outer shell is a rigid mesoporous material (such as amino-modified mesoporous silica) with nanopores and abundant reactive functional groups (such as amino groups). On the one hand, it provides stable mechanical support and chemical reaction sites, and on the other hand, its pores help water to quickly enter and exit the core.

[0081] The material of the hydrogel core described in this invention is not limited to a combination of polyvinyl alcohol (PVA) and polyacrylic acid (PAA). Those skilled in the art can select suitable alternative raw materials based on the following common requirements: (1) High hydrophilicity: The raw material should contain abundant hydrophilic groups, such as hydroxyl (-OH), carboxyl (-COOH), amide (-CONH2), sulfonic acid (-SO3H), etc., to ensure that the material has high moisture absorption properties. Alternative raw materials include, but are not limited to: polyacrylamide (PAM), poly(N-vinylpyrrolidone) (PVP), polyethylene glycol (PEG), polymethyl methacrylate (PMAA), sodium alginate, sodium carboxymethyl cellulose, etc.

[0082] (2) Crosslinkability: The raw materials should be able to form a stable three-dimensional network structure through chemical or physical crosslinking to ensure the structural integrity of the hydrogel during repeated swelling-shrinkage cycles. This can be achieved by adding crosslinking agents (such as N,N'-methylenebisacrylamide, glutaraldehyde, epichlorohydrin, etc.) or by utilizing physical interactions such as ionic crosslinking and hydrogen bonding.

[0083] (3) Volume response: The hydrogel network constructed from the selected raw materials should be able to undergo reversible volume expansion and contraction when the humidity changes, and the volume swelling rate should reach the aforementioned index (≥100%).

[0084] (4) Biocompatibility and environmental friendliness: Non-toxic, biodegradable or environmentally friendly raw materials are preferred to meet the safety and environmental protection requirements of textiles.

[0085] For example, the hydrogel core material can be a composite system of PVA and PAM, or an interpenetrating network system of PAA and PVP, both of which can achieve similar high moisture absorption and high expansion properties.

[0086] In this invention, polyvinyl alcohol / polyacrylic acid (PVA / PAA) interpenetrating network hydrogels are preferred materials for preparing the core of humidity-responsive microspheres. PVA provides the skeletal structure and high mechanical strength of the hydrogel, while PAA contributes a large number of carboxyl groups (-COOH), endowing the material with excellent hygroscopic properties and pH responsiveness. The synergistic effect of the two enables the hydrogel to undergo rapid, reversible, and significant volume swelling and shrinkage in response to humidity changes. Furthermore, those skilled in the art can also use combinations such as polyvinyl alcohol / polyacrylamide (PVA / PAM) or polyacrylic acid / polyN-vinylpyrrolidone (PAA / PVP) based on the same design principles. As long as the selected materials meet the common requirements of high hydrophilicity, crosslinkability, and humidity volume responsiveness, the technical effects of this invention can be achieved.

[0087] The pore size of the mesoporous silica shell is preferably 2-10 nm, more preferably 2-5 nm. This pore size range ensures rapid water passage to trigger a core response, while maintaining the mechanical integrity of the shell structure during repeated swelling-contraction cycles, and effectively anchoring functional load materials.

[0088] In addition to amino-modified mesoporous silica, the rigid mesoporous material may also be selected from one or a combination of the following alternative materials: Inorganic mesoporous materials: such as mesoporous alumina, mesoporous titanium dioxide, and mesoporous zirconium oxide; Organic / inorganic hybrid mesoporous materials: such as mesoporous organosilicon and metal-organic framework materials; Polymer-based mesoporous materials: such as mesoporous phenolic resins and mesoporous polydopamine; Carbon-based mesoporous materials: such as mesoporous carbon.

[0089] The aforementioned alternative materials must meet the following common requirements: (1) It has rigid support capacity and Young's modulus is not less than 1 GPa; (2) It has a mesoporous channel structure with a pore size in the range of 2-50 nm and a specific surface area of ​​not less than 200 m² / g; (3) The surface is functionalizable, which can introduce active functional groups that react with the adhesive system; (4) It exhibits chemical stability in the finishing and application environment; (5) It has good interfacial compatibility with the core material.

[0090] Overview of preparation methods: a. Hydrogel core synthesis: Polyvinyl alcohol (PVA, 3-8 parts by weight) is dissolved and reacted with acrylic acid (AA, 5-12 parts by weight) at 60-70°C for 4-8 hours in the presence of a crosslinking agent (such as N,N'-methylenebisacrylamide, 0.5%-1.5% of the total monomer mass) and an initiator to form a PVA / PAA IPN hydrogel, which is then purified and freeze-dried for later use.

[0091] b. Construction and Functionalization of Mesoporous Shell: Using the aforementioned dried hydrogel as a template, a mesoporous silica layer was coated onto its surface via a sol-gel method (using tetraethyl orthosilicate (TEOS), at an amount 1-3 times the mass of the hydrogel) in the presence of a surfactant template (such as CTAB). Subsequently, surface amination was performed using an aminosilane coupling agent (such as APTES, at an amount of 20%-50% of the TEOS mass) to finally obtain the target H-SRM microspheres. The volume swelling ratio of these microspheres reached 100%-200% when the relative humidity increased from 50% to 95%.

[0092] Flexible cross-linked network adhesive systems can adopt commercially available compounding schemes, such as those with the following composition (based on the percentage of total mass of the finishing agent working solution): Main film-forming resin (15%-25%): composed of epoxy-modified waterborne polyurethane dispersions (such as NeoRez). ® R-9620, etc. (dosage 12%-18%) and reactive silicone emulsions (such as Silok)® It is a compound of 8110 and others (3%-6% dosage), which work synergistically to provide strength, flexibility and reactivity.

[0093] Crosslinking agent (5%-15% of resin solids): preferably amino resin (such as hexamethoxymethyl melamine HMMM, trade name Cymel). ® 303) can covalently crosslink with the epoxy groups of polyurethane and the amino groups of microspheres during curing.

[0094] Catalyst (0.1%-0.5%): A latent acid catalyst (such as p-toluenesulfonic acid p-TSA) is used, which releases acidity during baking and efficiently catalyzes the above cross-linking reaction.

[0095] Adhesion promoters (0-2%, optional): such as silane coupling agent KH-560, used to enhance adhesion to synthetic fibers.

[0096] The low surface energy modifier uses long-chain alkylsiloxanes, preferably octadecyltrimethoxysilane, and is used in an amount of 0.5%-3.0% of the finishing agent working solution.

[0097] The working principle (intelligent pore-adjusting mechanism) of this fluorine-free fabric finishing agent is as follows: After padding-baking, the above components form a composite functional coating on the fabric. During the curing process, the crosslinking agent connects the polyurethane, silicone, microsphere shell, and fibers into a rigid-flexible three-dimensional interpenetrating network (IPN), firmly anchoring the microspheres. In dry / low-humidity environments: the H-SRM microspheres are in a contracted state, the coating structure is dense with very few pores, exhibiting excellent static water resistance (high hydrostatic pressure resistance, high water contact angle) and basic moisture permeability. In high-humidity / perspiration environments: ambient moisture is rapidly absorbed by the H-SRM microsphere core, causing it to swell dramatically. This expansion force acts on the flexible IPN network surrounding it, causing it to elastically deform, thereby "expanding" around the microspheres to form a large number of interconnected micron-level transient channels. These channels provide a high-speed diffusion path for water vapor (sweat), instantly increasing the moisture permeability several times over. Selective barrier function: Because the inner walls of all channels are composed of an IPN network modified with a low surface energy modifier, liquid water cannot wet or penetrate due to its high surface tension, thus ensuring that the waterproofness is not lost during dynamic processes. Reversibility: When the ambient humidity decreases, the microspheres dehydrate and shrink, and the elasticity of the IPN network restores them to their original shape, the channels close, and the system resets. This process can occur cyclically.

[0098] Unless otherwise specified, all raw materials used in all embodiments and comparative examples of this invention are commercially available industrial grade, and the process conditions are kept consistent except for specific variables. Finishing process: The fabric is pure cotton poplin (120g / m²). 2 The finishing process is one dip and one roll (75% roll-off), pre-drying at 100℃ for 2 minutes, and baking at 150℃ for 3 minutes.

[0099] In all embodiments and comparative examples of this invention, the properties of the fabrics were tested according to the following methods: (1) Hydrostatic pressure: Tested according to AATCC127-2003 standard. The sample size was 200mm×200mm, and conditioned for 4 hours at 21±2℃ and 65±2%RH. The test water was distilled water (21±2℃), and the pressure increase rate was 60mbar / min. The pressure values ​​(kPa) when three leaks appeared on the other side of the sample were recorded. Each sample was tested 3 times, and the average value was taken.

[0100] (2) Water contact angle: Tested according to GB / T42694-2023 standard. The seat drop method was used, with a droplet volume of 5 μL, and the measurement was performed at 20±2℃ and 65±4%RH. Each sample was measured 5 times at different positions, and the average value (°) was taken.

[0101] (3) Moisture permeability: Tested according to ASTM E96 / E96MBW method (inverted cup water method). Test conditions are divided into "normal humidity" (25±0.6℃, 65±2%RH) and "high humidity" (35±0.6℃, 90±2%RH), with wind speed of 0.02-0.3m / s. Weighing is performed every hour, and moisture permeability (g / m³) is calculated from 8-10 consecutive stable points. 2 •24h).

[0102] (4) Washability: Accelerated washing test was conducted according to AATCC 61-2020 2A procedure. Temperature 49±2℃, soap solution 150mL, detergent concentration 0.15%, 50 steel balls, washing time 45 minutes (equivalent to 5 household washes). After 1 cycle (5 washes) and 6 cycles (30 washes) respectively, hydrostatic pressure, high wet permeability and waterproof rating (AATCC TM22:2024 "Waterproofing Test Method: Spray") were tested, and the performance retention rate was calculated.

[0103] (5) Antibacterial properties: Tested according to AATCC 100-2019 standard. The test strains were Staphylococcus aureus and Escherichia coli, and the bacterial suspension concentration was 1×10⁻⁶. 6 CFU / mL, incubated at 37℃ for 24 hours. Antibacterial rate (%) = [(initial viable count - viable count after incubation) / initial viable count] × 100%. Wash resistance antibacterial performance was tested repeatedly after 30 washes according to AATCC 61-2020 2A procedure.

[0104] Example 1 This example provides an adaptive pore-forming fluorine-free fabric finishing agent based on humidity-responsive microspheres. This finishing agent is prepared from an aqueous dispersion of the following raw materials: humidity-responsive intelligent pore-forming microspheres, and an adhesive (NeoRez). ®R-9620 15.0%, Silok ® 8110 4.0%, Cymel ® The preparation process involves 1.8% 303, 0.3% p-TSA (40% aqueous solution), KH-560, and a low surface energy modifier (octadecyltrimethoxysilane). The preparation process is as follows: 1) Preparation of humidity-responsive smart pore-forming microspheres (H-SRM): (1) Synthesis of a highly hygroscopic hydrogel core: PVA / PAA hydrogels were synthesized using interpenetrating polymer network (IPN) technology as the main raw materials, namely polyvinyl alcohol (PVA, degree of hydrolysis ≥98%, degree of polymerization approximately 1700) and acrylic acid (AA, purity ≥99%, polymerization inhibitor removed by vacuum distillation before use). Specifically, 5.0 g of PVA was dissolved in 100 mL of 90°C hot water, cooled to 60°C, and then dissolved again to obtain a homogeneous solution. The solution was cooled to 60°C to control the subsequent polymerization rate and avoid side reactions. 8.0 mL of AA and 0.08 g of crosslinking agent N,N'-methylenebisacrylamide (MBA) were added. Under nitrogen protection, 0.05 g of potassium persulfate (KPS) initiator was added, and the reaction was carried out at 65±2°C for 6 hours. The resulting gel was purified and freeze-dried to obtain porous PVA / PAA hydrogel blocks.

[0105] (2) Construction and amination of mesoporous silica shell: Take 2.0 g of the above-mentioned dried hydrogel powder and disperse it in a 150 mL ethanol / 20 mL water mixture containing 1.0 g of hexadecyltrimethylammonium bromide (CTAB). Add 3.0 mL of concentrated ammonia and 4.0 mL of tetraethyl orthosilicate (TEOS), and react at room temperature for 24 hours. Centrifuge to collect the solid, redisperse it in 100 mL of ethanol, add 1.5 mL of 3-aminopropyltriethoxysilane (APTES), and reflux at 60 °C for 6 hours. After washing and drying, the morphology of the obtained microspheres is characterized by scanning electron microscopy and microscopy, and the results are as follows. Figure 1 and 2 As shown in the figure, the present invention yielded H-SRM microspheres with an average particle size of 1-3 μm. Figure 2The microspheres exhibit a core-shell structure. Furthermore, TEM characterization revealed that the outer shell has a mesopore size of approximately 3–5 nm and a surface amine density >2.5 wt% (tested using chemical derivatization-X-ray photoelectron spectroscopy (CD-XPS). H-SRM microspheres were reacted with 5-iodo-2-furanaldehyde (IFA) at room temperature for 2 hours, thoroughly washed, and then vacuum dried. The surface primary amine content was calculated by measuring the I 3d and N 1s peak intensities using XPS. Amino density (wt%) = (number of moles of surface amino groups × 16 g / mol) / microsphere mass × 100%. The experimentally measured surface amine density of H-SRM microspheres was >2.5 wt%). The volume swelling rate of these microspheres reached 150% ± 20% when the relative humidity increased from 50% to 95%.

[0106] 2) Preparation of finishing agent: Prepare the working solution according to the following mass percentages: H-SRM microspheres 5.0%, NeoRez ® R-9620 15.0%, Silok ® 8110 4.0%, Cymel ® 303 1.8%, p-TSA (40% aqueous solution) 0.3%, KH-560 1.0%, octadecyltrimethoxysilane 1.5%, and deionized water to 100%. After ultrasonic dispersion of H-SRM, it is mixed with the other pre-emulsified components and stirred for 30 minutes to obtain an aqueous dispersion, which is the adaptive pore-regulating fluorine-free fabric finishing agent based on humidity-responsive microspheres.

[0107] Example 2 This example provides an adaptive pore-adjusting fluorine-free fabric finishing agent based on humidity-responsive microspheres. Compared with Example 1, it only changes the amount of H-SRM microspheres added to 2%, while keeping other conditions unchanged.

[0108] Example 3 This example provides an adaptive pore-adjusting fluorine-free fabric finishing agent based on humidity-responsive microspheres. Compared with Example 1, it only changes the amount of H-SRM microspheres added to 8%, while keeping other conditions unchanged.

[0109] The fluorine-free fabric finishing agents prepared in Examples 1-3 were applied to fabrics using the aforementioned finishing process. The fabric performance was then evaluated and tested, and the results are shown in Table 1 below: Table 1

[0110] As shown in the table above, the H-SRM content has a certain impact on the performance of fluorine-free fabric finishing agents. When the content is around 5.0%, the overall performance is superior, maintaining good static water resistance (hydrostatic pressure 48 kPa), achieving the highest intelligent response sensitivity (moisture permeability change factor of 3.15), and exhibiting the best durability. When the microsphere content decreases, the density of the "driving units" within the coating decreases, reducing the moisture permeability channels formed under high humidity conditions, resulting in the smallest increase in moisture permeability. However, this dense coating structure also leads to higher hydrostatic pressure. When the microsphere content increases, the absolute moisture permeability increases, but the integrity of the continuous phase of the binder is disrupted, leading to a decrease in static water resistance (hydrostatic pressure) and coating mechanical strength (manifested as a decrease in retention rate after washing).

[0111] Examples 4-6 This example provides an adaptive pore-regulating fluorine-free fabric finishing agent based on humidity-responsive microspheres. Compared to Example 1, the only difference is the adjustment of the amounts of NeoRez® R-9620 (PU) and Silok® 8110 (Si). (In this example, NeoRez® R-9620 is an epoxy-modified waterborne polyurethane, and Silok® 8110 is a reactive organosilicon; the two are combined to form a film-forming resin.) The total amount of both is maintained at 19.0%, as shown in Table 2 below. Furthermore, the fluorine-free fabric finishing agents obtained in Examples 4-6 were applied to fabrics using the aforementioned finishing process, and the fabric performance was evaluated. The results are also shown in Table 2 below. Table 2

[0112] As shown in Table 2, the PU:Si ratio has a significant impact on the overall performance of the finishing agent. The finishing agent achieves its optimal performance when the PU:Si ratio is approximately 15:4. At this ratio, polyurethane provides sufficient strength and crosslinking points, ensuring the coating has a complete structure and good adhesion. Simultaneously, the introduction of silicone significantly improves flexibility, allowing the coating to better respond to the expansion force of the microspheres, resulting in higher dynamic moisture permeability. Furthermore, it imparts excellent hand feel and outstanding wash durability. When silicone is not added to the finishing agent, the coating is more rigid, which limits the deformation ability of the microspheres during expansion, leading to a reduced dynamic moisture permeability response. In addition, the coating without silicone has a harder hand feel, and during washing, repeated bending can easily cause microcracks on the coating surface. While a higher silicone content in the finishing agent increases flexibility and moisture permeability, it may lead to insufficient crosslinking density. This not only reduces static waterproof strength but also causes the overly soft coating to stick to rollers during processing, potentially leading to durability issues.

[0113] Examples 7-9 This example provides an adaptive pore-regulating fluorine-free fabric finishing agent based on humidity-responsive microspheres. Compared with Example 1, only the amount of octadecyltrimethoxysilane is changed, as shown in Table 3 below. Furthermore, after applying the prepared fluorine-free fabric finishing agent to the fabric using the aforementioned finishing process, the performance test results of the fabric are also shown in Table 3. Table 3

[0114] As shown in Table 3, low surface energy agents are the key factor in maintaining the superhydrophobicity of the finishing agent. The overall performance of the coating reaches its optimal state when the addition amount of low surface energy agent is approximately 1.5%. At this addition level, the material maintains excellent and durable waterproof performance while minimizing the impact of moisture permeability. Reducing the addition amount of low surface energy agent decreases its coverage on the coating and the inner surface of the dynamic pores. This weakens the initial hydrophobicity of the material, making it more susceptible to degradation during washing. Conversely, increasing the addition amount of low surface energy agent may lead to excessive accumulation of long-chain alkyl groups. This excessive accumulation can create steric hindrance or kinetic obstacles to the swelling of microspheres and the unobstructed flow of pores, resulting in a slight decrease in the dynamic moisture permeability of the material. However, at the same time, the wash durability of the material is significantly improved.

[0115] Example 10 This example provides an adaptive pore-regulating fluorine-free fabric finishing agent based on humidity-responsive microspheres. The difference from Example 1 is that 1.5% silver ions (Ag) are loaded into the aminated mesoporous silica shell of the H-SRM microspheres via ion exchange. + The prepared fluorine-free fabric finishing agent was applied to the fabric using the aforementioned finishing process. The fabric performance was then evaluated and tested. The results are as follows: Intelligent pore adjustment performance: hydrostatic pressure 40 kPa, high wet permeability 8000 g / m³ 2 • 24h, equivalent to Example 1.

[0116] Antibacterial properties (AATCC 100): The inhibition rate against Staphylococcus aureus and Escherichia coli is >99.9%.

[0117] Durability: After 30 washes, the antibacterial rate remains above 99%, and the high-humidity moisture permeability retention rate is 80%.

[0118] The above results demonstrate that this embodiment proves the platform advantages of the fluorine-free fabric finishing agent of the present invention. Without affecting the core intelligent pore adjustment function, the antibacterial function can be easily integrated through the functional design of microspheres.

[0119] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A fluorine-free fabric finishing agent, characterized in that: The fluorine-free fabric finishing agent is a water-based dispersion, which includes the following raw materials: humidity-responsive smart pore-forming microspheres, binder and low surface energy modifier. The humidity-responsive smart pore-forming microspheres include a core and a shell, wherein the core contains an interpenetrating network hydrogel and the shell contains a rigid mesoporous material with reactive functional groups on its surface.

2. The fluorine-free fabric finishing agent according to claim 1, characterized in that: The raw materials for preparing the interpenetrating network hydrogel satisfy at least one of the following characteristics: 1) having hydrophilic groups; 2) having crosslinkability; 3) having humidity volume responsiveness; and / or, the interpenetrating network hydrogel contains at least one of the following components: polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyN-vinylpyrrolidone, polyethylene glycol, polymethacrylic acid, sodium alginate, and sodium carboxymethyl cellulose.

3. The fluorine-free fabric finishing agent according to claim 1, characterized in that: The interpenetrating network hydrogels include polyvinyl alcohol / polyacrylic acid hydrogels, polyvinyl alcohol / polyacrylamide hydrogels, or polyacrylic acid / polyN-vinylpyrrolidone hydrogels.

4. The fluorine-free fabric finishing agent according to claim 1, characterized in that: The reactive functional group includes at least one of amino, hydroxyl, carboxyl, epoxy, and mercapto groups; and / or, the rigid mesoporous material includes at least one of inorganic mesoporous materials, organic / inorganic hybrid mesoporous materials, polymer-based mesoporous materials, or carbon-based mesoporous materials.

5. The fluorine-free fabric finishing agent according to claim 1, characterized in that: The adhesive comprises the following raw materials: film-forming resin, crosslinking agent I, and catalyst, optionally further comprising an adhesion promoter; wherein the film-forming resin comprises epoxy-modified waterborne polyurethane and reactive organosilicon.

6. The fluorine-free fabric finishing agent according to claim 5, characterized in that: The mass ratio of the epoxy-modified waterborne polyurethane to the reactive organosilicon is 4~6:1~2.

7. The fluorine-free fabric finishing agent according to claim 1, characterized in that: The low surface energy modifier includes long-chain alkylsiloxanes; and / or, the mass percentage of the low surface energy modifier in the fluorine-free fabric finishing agent is 1-2%.

8. The method for preparing the fluorine-free fabric finishing agent according to any one of claims 1 to 7, characterized in that: Includes the following steps: S1. Preparation of humidity-responsive smart porous microspheres: A hydrogel core is synthesized and dried. A mesoporous material layer is coated on the surface of the core by a sol-gel method in the presence of a template agent. Reactive functional groups are modified on the surface of the mesoporous material layer. S2. Mix the humidity-responsive smart pore-forming microspheres, adhesive, and low surface energy modifier obtained in step S1 with water to prepare an aqueous dispersion.

9. The application of the fluorine-free fabric finishing agent according to any one of claims 1 to 7 in the field of clothing.

10. A fabric, characterized in that: The fabric includes a body and a coating on the surface of the body, wherein the raw materials for preparing the coating include the fluorine-free fabric finishing agent as described in any one of claims 1 to 7.

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