Bio-based heat storage composite fabric, preparation method thereof and outdoor protective clothing

Abstract

This invention discloses a bio-based thermal storage composite fabric, its preparation method, and outdoor protective clothing. The bio-based thermal storage composite fabric employs a layered composite structure, including a top layer, a middle layer, and a bottom layer. The middle layer is a biomass waterproof, breathable, and heat-generating membrane, whose raw materials, by mass percentage, include: 75% polyether breathable polyurethane resin, 20% bio-based components derived from castor oil, and 5% inorganic heat-generating powder composed of zirconium oxide and titanium oxide. This invention provides a bio-based thermal storage composite fabric, its preparation method, and outdoor protective clothing. Through innovative formulation of the core functional membrane layer, this fabric simultaneously achieves high bio-based environmental protection content, efficient active heat storage capacity, and excellent waterproof and breathable performance, overcoming the problems of single function, insufficient environmental protection, and difficulty in synergistic performance in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of functional textile fabric technology, specifically to a bio-based heat-retaining composite fabric, its preparation method, and outdoor protective clothing. Background Technology

[0002] Outdoor sportswear, especially waterproof jackets, places high demands on the multi-functional integration of fabrics. Currently, fabrics on the market often struggle to achieve a good balance between various properties. For example, introducing far-infrared heating materials to improve warmth often leads to a decrease in the fabric's waterproof and breathable properties or a stiffer feel; while using bio-based materials for environmental protection often faces challenges in terms of mechanical strength, durability, and compatibility with functional fillers, making it difficult to meet the high-performance standards required for professional outdoor protection. Therefore, how to maintain or even synergistically improve the waterproof, breathable, and durable properties of membranes while introducing bio-based components and functional powders has long been a unresolved contradiction in existing technologies. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects or problems in the prior art and provide a bio-based heat-storing composite fabric, its preparation method and outdoor protective clothing. This fabric achieves high bio-based environmental protection content, efficient active heat storage capacity and excellent waterproof and breathable performance through the formulation innovation of the core functional membrane layer, so as to overcome the problems of single function, insufficient environmental protection and difficulty in synergistic performance in the prior art.

[0004] Through continuous observation, analysis, and experimentation, it was discovered that the root cause of the difficulty in achieving high-performance, multi-functional fabrics in existing technologies lies in the inherent contradiction between bio-based components, inorganic functional powders, and the matrix resin: the introduction of bio-based components usually alters the crystallinity and compatibility of polyurethane molecules, potentially degrading the film's density and strength; while the excessive addition of inorganic powders easily disrupts film continuity, creating defects and impairing waterproofing. Simply increasing the content of both to pursue environmental friendliness and functionality often leads to a trade-off, resulting in a decline in overall performance.

[0005] This application recognizes that the key to resolving this contradiction is not the replacement of a single material, but rather finding a formulation system that can achieve synergistic coexistence and complementary performance among the three.

[0006] The aforementioned defects in the background art are due to their being a first-time discovery. Based on this, and in order to improve upon these defects and achieve the objective of this application, the following technical solution is adopted to address the problem:

[0007] The first technical solution relates to a bio-based heat storage composite fabric, which adopts a layered composite structure, including a top layer, a middle layer and a bottom layer; the middle layer is a biomass waterproof and breathable heat-generating membrane, the raw materials of which include, by mass percentage: 75% polyether breathable polyurethane resin, 20% bio-based components derived from castor oil, and 5% inorganic heat-generating powder composed of zirconium oxide and titanium oxide.

[0008] In the above design, the specific mass ratio of 75:20:5 (polyether permeable polyurethane resin: bio-based components: inorganic exothermic powder) is not a simple addition of components, but rather the construction of a mutually supportive performance triangle. This ratio precisely finds the critical balance point between the environmental appeal of bio-based components, the addition of functional powders, and the maintenance of the performance of the matrix resin. Any significant deviation of any component will break this balance, leading to one or more deteriorations in permeability, water pressure resistance, or heat storage performance. The selection of hydrolysis-resistant polyether polyurethane resin as the continuous phase (75%) provides excellent hydrolysis resistance due to the ether bond (-COC-) structure in its molecular chain. This directly defines the fundamental reason for achieving hydrolysis resistance from a chemical structure perspective. Compared to ester bonds, ether bonds are less sensitive to water molecule attacks, thus ensuring, from a molecular design perspective, that the intermediate layer composed of this resin can maintain stable physical properties over a long period, even in a complex system containing 20% ​​bio-based components and 5% inorganic powders, preventing problems such as decreased membrane strength and reduced permeability caused by hydrolysis. This characteristic lays the foundation for addressing the potential durability risks associated with the subsequent introduction of bio-based components and inorganic powders, ensuring the reliability of the membrane during long-term operation in humid environments—something difficult to achieve with polyester-based resins or other types of resins. Precisely controlling the addition of castor oil-derived bio-based components to 20% yields multiple optimization effects: First, its long-chain fatty acid structure, acting as flexible segments, effectively improves the membrane's flexibility and low-temperature impact resistance, offsetting the brittleness that inorganic powders might introduce; second, this proportion of bio-based components improves the wetting and coating of inorganic powders by the resin matrix, reducing interphase interface defects—a crucial effect when the powder content is 5%; finally, the 20% addition provides environmental value without excessively interfering with the polyether resin's ability to form a continuous, dense film, ensuring a solid foundation for waterproof and breathable performance. Limiting the total addition of inorganic exothermic powder, composed of zirconium oxide and titanium oxide in a specific ratio, to 5% achieves a balance between function and structure. The synergistic effect of zirconium oxide's heat storage properties and titanium oxide's high thermal conductivity allows for highly efficient heat absorption, storage, and radiation effects even at a low addition level. Structurally, this composite composition maximizes the uniform dispersion of the powder in the resin, avoiding defects such as film microporous structure damage and increased pinholes caused by powder agglomeration or excessive addition. This is crucial for maintaining high hydrostatic pressure (≥15000 mm). The synergistic effect of these three factors ultimately results in the composite fabric maintaining a high bio-based content (20%) and effective functional powder addition (5%) while its core protective performance indicators are improved. Tests show that its hydrostatic pressure can reach over 15000 mm, and its moisture permeability exceeds 7000 g / m²·24h. It also possesses active heat storage capabilities, resolving the inherent contradiction in traditional technologies where environmental protection, functionality, and high performance are difficult to balance.

[0009] In a preferred embodiment, the mass ratio of zirconium oxide to titanium oxide in the inorganic exothermic powder is 3:2.

[0010] In the above design, zirconium oxide and titanium oxide are composited at a mass ratio of 3:2. This specific ratio allows the two functional powders to have a clear division of roles and complementary efficiencies in the heat storage mechanism. Zirconia acts as the main energy storage unit, while titanium oxide acts as a highly efficient heat conduction and distribution unit. With its high thermal conductivity, titanium oxide rapidly transfers the absorbed heat to the entire film layer and promotes the transport of heat to the zirconium oxide particles and the uniform radiation from the zirconium oxide outwards. The 3:2 ratio optimizes the contribution balance of the two mechanisms within a limited total addition (5%), making the composite powder more efficient in the entire process of absorbing, transferring, and re-radiating heat, achieving a synergistic heat storage effect, and improving the heat storage performance per unit mass of powder.

[0011] As a preferred embodiment, the inorganic exothermic powder is composed of micron-sized zirconium oxide powder and nano-sized titanium oxide powder.

[0012] In the above design, the inorganic exothermic powder is composed of micron-sized zirconium oxide and nano-sized titanium oxide. The nano-sized titanium oxide powder is finer than the micron-sized zirconium oxide, which is more beneficial to the hydrostatic pressure of the membrane material, while also better taking into account the heat storage performance.

[0013] In a preferred embodiment, the titanium oxide component in the inorganic heating powder is composed of nanoparticles with an average particle size of less than 100 nm, and the overall average particle size of the inorganic heating powder is 1-5 μm.

[0014] In the above design, titanium dioxide consists of nanoparticles with an average particle size of less than 100 nm, and the overall composite powder particle size is 1-5 μm. The extremely high surface activity of nano-titanium dioxide enhances its interfacial bonding with resin and bio-based components, reducing the tendency of powder agglomeration. At the same time, controlling the upper limit of the overall particle size to within 5 μm ensures that the powder will not puncture the membrane and form leakage points due to excessive size in the ultrathin (approximately 0.02 mm) functional membrane, which helps maintain hydrostatic pressure exceeding 15000 mm.

[0015] As a preferred embodiment, the bottom layer is a warp-knitted fleece fabric with a weight of 60-70 g / m² and a short pile structure.

[0016] In the above design, the bottom layer is a warp-knitted fleece fabric with a short pile structure and a weight of 60-70 g / m². This warp-knitted fleece structure ensures warmth (by locking in air layers for enhanced insulation) and also provides excellent anti-snagging and anti-pilling properties. The weight range of 60-70 g / m² provides an ideal base thickness for the heat-sealing process: too light a material lacks fullness and warmth, while too heavy a material results in insufficient pressure during sealing. Combining the inherent dimensional stability of the warp-knitted structure with the short pile structure, this design solves the industry problem of poor adhesive bonding and water seepage caused by the excessively thick pile and loose structure of traditional fleece (weft-knitted, long-pile) during sealing, achieving a balance between warmth and processing reliability.

[0017] In a preferred embodiment, the basis weight of the bottom layer is 65 g / m².

[0018] The above design further optimizes the bottom layer weight to 65g / m², which is the preferred embodiment, ensuring both warmth retention and heat sealing effect.

[0019] In a preferred embodiment, the surface layer is a woven fabric made of fully dull polyester filaments with warp and weft yarns of 150D / 144F.

[0020] In the above design, the outer layer is a woven fabric of fully matte polyester filament with a specific specification (150D / 144F). The fabric woven from this specification of yarn ensures sufficient abrasion resistance and tear resistance, while the fully matte treatment and fine texture give the fabric an excellent matte texture and soft feel, enhancing the appearance and wearing comfort of the garment, making it more suitable for the application requirements of high-end outdoor clothing.

[0021] As a preferred embodiment, the thickness of the biomass waterproof and breathable heating membrane is 0.02mm ± 0.005mm.

[0022] In the above design, the thickness of the biomass waterproof, breathable, and heat-generating membrane is 0.02mm ± 0.005mm. The membrane thickness is sufficient to accommodate 5% powder and form a continuous, defect-free microporous structure, ensuring the full utilization of the waterproof and breathable function; at the same time, it is thin enough to allow the final three-layer composite fabric to maintain excellent softness and drape.

[0023] A method for preparing the above-mentioned bio-based heat-storing composite fabric includes the following steps: S1. Preparing a biomass waterproof, breathable, and heat-generating membrane: mixing the polyether breathable polyurethane resin with a solid content of 30%, the bio-based component, and the inorganic heat-generating powder to form a slurry with a viscosity of 8000±500cps, coating it on release paper at a coating amount of 180±10g / m², and then performing step-by-step baking and curing to form the biomass waterproof, breathable, and heat-generating membrane; S2. First lamination: bonding the biomass waterproof, breathable, and heat-generating membrane to the surface layer using polyurethane reactive hot melt adhesive; S3. Second lamination: bonding the fabric after step S2 to the bottom layer using polyurethane reactive hot melt adhesive.

[0024] The aforementioned preparation method, particularly the stepped baking curing and PUR hot melt adhesive dot bonding, ensures that the advantages of each component design are realized in the final product. Through optimization of key parameters such as stepped baking temperature control, precise coating amount control, and curing process, the quality stability of the biomass waterproof, breathable, and heat-generating membrane and composite fabric is ensured, making them suitable for industrial production.

[0025] As a preferred embodiment, the temperature ranges for the stepped baking and curing process are: 80℃, 100℃, 120℃, 150℃, and 150℃.

[0026] In the above design, the stepped baking and curing process involves a five-stage temperature increase: 80℃, 100℃, 120℃, 150℃, and 150℃. The initial gradient temperature increase (80-120℃) facilitates stable solvent evaporation, preventing pinholes on the film surface caused by excessively rapid evaporation. The two final curing zones at 150℃ are primarily designed to ensure the complete removal of high-boiling-point organic solvents used in the slurry (such as N,N-dimethylformamide and DMF, whose boiling point is approximately 150℃). Furthermore, controlling the maximum temperature at 150℃ rather than higher is also for the protection of the release paper carrier. This minimizes thermal damage to the release paper while ensuring complete solvent evaporation and sufficient resin cross-linking, thus maintaining its reusability.

[0027] In a preferred embodiment, after step S2 and / or step S3, a curing step is further included, wherein the curing is carried out in an environment with a relative humidity of 60%-70% for 24 hours.

[0028] In the above design, the adhesive is cured for 24 hours at a specific humidity level (60%-70% RH). This condition provides an optimal environment for the moisture curing reaction of the PUR hot melt adhesive, ensuring that the adhesive layer is fully and uniformly cross-linked, thereby obtaining a large and stable peel strength. This allows the three-layer composite structure to withstand repeated washing and stress tests in actual use, improving the durability of the fabric.

[0029] An outdoor protective garment is made from the aforementioned bio-based heat-retaining composite fabric.

[0030] In the above design, the outdoor protective clothing made from the above-mentioned fabric inherits all the functional advantages of the fabric. The final product has excellent wind and water resistance, high moisture permeability and comfort, active warmth retention and reliable seam sealing in actual use, meeting the stringent requirements of high-end outdoor sports for clothing performance. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims and description of this invention is for distinguishing different objects, not for describing a specific order.

[0033] Unless otherwise expressly defined, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," and "counterclockwise" in the claims and description of this invention is merely for the convenience of describing the invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific scope of protection of this invention.

[0034] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims and description of this invention should be interpreted broadly to refer to any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection, and fixed connection by other means or components.

[0035] In the claims and description of this invention, the terms “comprising,” “having,” and variations thereof are used in a manner intended to mean “including but not limited to.”

[0036] A bio-based thermal storage composite fabric is a multi-layered functional fabric that mimics a sandwich structure. It employs a layered composite structure, including a top layer, a middle layer, and a bottom layer.

[0037] The outer layer, as the fabric's outermost layer, primarily serves to protect, resist abrasion, and provide initial water repellency. Conventional woven polyester fabrics can be used. In a preferred embodiment, the outer layer is woven to ensure dimensional stability and tear resistance. More specifically, 150D / 144F fully dull polyester filament can be used as both warp and weft yarns. This fine denier, high F-number yarn gives the fabric a delicate and soft touch, while the fully dull finish enhances its premium appearance. For example, the warp and weft densities can be set to 87 ends / inch and 80 ends / inch respectively, with a width of 58 inches, ultimately resulting in a polyester spring spun fabric commonly used in outdoor fabrics.

[0038] The middle layer is the core functional layer, a thin film that combines bio-based environmental protection characteristics, active heat storage, and highly efficient waterproof and breathable functions. The realization of this biomass waterproof and breathable heating film relies on a precisely balanced formulation system, including the synergistic effect of matrix resin, bio-based components, and inorganic heating powder.

[0039] The matrix resin is a liquid-type polyether permeable polyurethane resin as the continuous phase, with a solid content of 30%. The soft segments of the molecular chain of this type of resin are mainly composed of ether bonds (-COC-). This chemical structure provides excellent hydrolysis resistance, laying the foundation for long-term stable operation in humid environments and making it possible to introduce other components that are susceptible to water.

[0040] The bio-based component, consisting of castor oil-derived bio-based ingredients, comprises 20% by weight. The long-chain structure of castor oil molecules, acting as flexible segments, effectively improves the flexibility and low-temperature performance of the final film. Simultaneously, it promotes the wetting and coating of subsequently added inorganic powders by the resin. This 20% addition provides environmental value while ensuring that it does not excessively interfere with the polyurethane's ability to form a continuous, dense, waterproof membrane.

[0041] The inorganic exothermic powder is a composite inorganic exothermic powder with a total addition of 5%, which is composed of zirconium oxide (ZrO2) and titanium oxide (TiO2) in a mass ratio of 3:2. The titanium oxide preferably uses nanoparticles with an average particle size of less than 100 nm to increase the specific surface area, while the overall average particle size of the composite powder is controlled at 1-5 μm. Micron-sized zirconium oxide mainly plays a role in heat storage, while nano-sized titanium oxide constructs an efficient heat conduction network, accelerating heat transfer. The two work synergistically to achieve high heat storage efficiency with low addition amounts. Simultaneously, particle size control ensures uniform dispersion of the inorganic exothermic powder in the matrix resin, preventing agglomeration or excessively large particles from puncturing the film and compromising its waterproof integrity.

[0042] The above-mentioned mixture is coated and cured to form a film of uniform thickness. The preferred film thickness is 0.02 mm (tolerance ±0.005 mm). This thickness ensures functionality while maximizing the fabric's softness.

[0043] As the inner layer closest to the skin, the bottom layer needs to provide comfort and warmth, and its compatibility with garment manufacturing processes must be carefully considered. This embodiment uses warp-knitted fleece as the bottom layer. Its weight is preferably in the range of 60-70 g / m², more preferably 65 g / m². Unlike weft-knitted fleece commonly used for warmth, warp-knitted structures are inherently more compact and stable. The short pile structure formed by the napping process not only traps air for warmth but also, due to its short pile and dense fabric base, allows for thorough bonding of the adhesive strip to the fabric base during the subsequent heat-sealing process in garment manufacturing. This effectively solves the industry pain point of easy water leakage at the seam of traditional long-pile fleece.

[0044] The preparation of this composite fabric mainly includes two stages: functional film forming and layer lamination, specifically including the following steps:

[0045] 1. Preparation of biomass waterproof and breathable heating membrane:

[0046] a. Ingredients and Mixing: Accurately weigh the raw materials according to the following mass percentages (75% polyether permeable polyurethane resin, 20% castor oil bio-based component, and 5% zirconium oxide / titanium oxide composite powder). Add the polyurethane resin with a solid content of 30%, the bio-based component, and the inorganic powder to a mixer and mix thoroughly until homogeneous, forming a slurry with a viscosity of approximately 8000±500 cps.

[0047] b. Coating and Curing: The uniformly mixed slurry is coated using a release paper coating process, with the coating amount controlled at 180±10 g / m². Subsequently, the release paper carrying the wet film is placed in an oven with multiple independent temperature zones for stepped baking and curing. The oven temperatures are set sequentially at 80℃, 100℃, 120℃, 150℃, and 150℃. This temperature profile is designed based on the following considerations: the initial gradient temperature increase (80-120℃) facilitates stable solvent evaporation, avoiding pinholes on the film surface due to excessively rapid evaporation; the two final curing zones at 150℃ are primarily intended to ensure the complete removal of high-boiling-point organic solvents used in the slurry (such as N,N-dimethylformamide, DMF, whose boiling point is approximately 150℃). Simultaneously, controlling the maximum temperature at 150℃ rather than higher is also for the protection of the release paper carrier, minimizing thermal damage to the release paper and maintaining its reusability while ensuring complete solvent evaporation and sufficient resin cross-linking. This curing process ultimately forms a dense and stable functional membrane. After film formation, it is wound up and cured at room temperature for 24 hours to eliminate internal stress and stabilize the membrane properties before use.

[0048] 2. Interlayer composite:

[0049] a. First lamination (top layer and intermediate layer): The above-mentioned functional film is bonded to the polyester top layer using a polyurethane reactive (PUR) hot melt adhesive dot bonding process. The adhesive application rate is approximately 8-10 g / m², and the lamination temperature is controlled at around 110-130℃. After lamination, curing is required: the material is placed in an environment with a relative humidity of 60%-70% for approximately 24 hours to allow the PUR adhesive to fully react with the moisture in the air and achieve the final bonding strength.

[0050] b. Second lamination (with the base layer): The semi-finished product from the first lamination is then laminated again with a warp-knitted fleece base fabric weighing 60-70 g / m² using a PUR hot melt adhesive dot bonding process. The adhesive application rate is approximately 8-10 g / m², and the temperature remains around 110-130℃. After lamination, the fabric is placed in an environment with a relative humidity of 60%-70% for approximately 24 hours for curing, ultimately resulting in a three-layer composite fabric.

[0051] In this embodiment, the specific mass ratio of 75:20:5 (polyether permeable polyurethane resin: bio-based component: inorganic exothermic powder) is not a simple addition of components, but rather the construction of a mutually supportive performance triangle. This ratio precisely finds the critical balance point between the environmental appeal of bio-based materials, the addition of functional powder, and the maintenance of the performance of the matrix resin. Any significant deviation of any component will break this balance, leading to one or more deteriorations in permeability, water pressure resistance, or heat storage performance. A hydrolysis-resistant polyether polyurethane resin is selected as the continuous phase (75%). The ether bond (-COC-) structure in its molecular chain provides excellent hydrolysis resistance, which directly defines the fundamental reason for achieving hydrolysis resistance from a chemical structure perspective. Compared to ester bonds, ether bonds are less sensitive to water molecule attacks, thus ensuring, from a molecular design perspective, that the intermediate layer composed of this resin can maintain stable physical properties for a long time, even in a complex system containing 20% ​​bio-based component and 5% inorganic powder, preventing problems such as decreased membrane strength and reduced permeability due to hydrolysis. This characteristic lays the foundation for addressing the potential durability risks associated with the subsequent introduction of bio-based components and inorganic powders, ensuring the reliability of the membrane during long-term operation in humid environments—something difficult to achieve with polyester-based resins or other types of resins. Precisely controlling the addition of castor oil-derived bio-based components to 20% yields multiple optimization effects: First, its long-chain fatty acid structure, acting as flexible segments, effectively improves the membrane's flexibility and low-temperature impact resistance, offsetting the brittleness that inorganic powders might introduce; second, this proportion of bio-based components improves the wetting and coating of inorganic powders by the resin matrix, reducing interphase interface defects—a crucial effect when the powder content is 5%; finally, the 20% addition provides environmental value without excessively interfering with the polyether resin's ability to form a continuous, dense film, ensuring a solid foundation for waterproof and breathable performance. Limiting the total addition of inorganic exothermic powder, composed of zirconium oxide and titanium oxide in a specific ratio, to 5% achieves a balance between function and structure. The synergistic effect of zirconium oxide's heat storage properties and titanium oxide's high thermal conductivity allows for highly efficient heat absorption, storage, and radiation effects even at a low addition level. Structurally, this composite composition maximizes the uniform dispersion of the powder in the resin, avoiding defects such as film microporous structure damage and increased pinholes caused by powder agglomeration or excessive addition. This is crucial for maintaining high hydrostatic pressure (≥15000 mm). The synergistic effect of these three factors ultimately results in the composite fabric maintaining a high bio-based content (20%) and effective functional powder addition (5%) while its core protective performance indicators are improved. Tests show that its hydrostatic pressure can reach over 15000 mm, and its moisture permeability exceeds 7000 g / m²·24h. It also possesses active heat storage capabilities, resolving the inherent contradiction in traditional technologies where environmental protection, functionality, and high performance are difficult to balance.

[0052] In this embodiment, zirconium oxide and titanium oxide are composited at a mass ratio of 3:2. This specific ratio allows the two functional powders to have a clear division of roles and complementary efficiencies in the heat storage mechanism. Zirconia acts as the main energy storage unit, while titanium oxide acts as a highly efficient heat conduction and distribution unit. With its high thermal conductivity, titanium oxide rapidly transfers the absorbed heat to the entire film layer and promotes the transport of heat to the zirconium oxide particles and the uniform radiation from the zirconium oxide outwards. The 3:2 ratio optimizes the contribution balance of the two mechanisms within a limited total addition (5%), making the composite powder more efficient in the entire process of absorbing, transferring, and re-radiating heat, achieving a synergistic heat storage effect, and improving the heat storage performance per unit mass of powder.

[0053] In this embodiment, the titanium dioxide is composed of nanoparticles with an average particle size of less than 100 nm, and the overall composite powder particle size is 1-5 μm. The extremely high surface activity of nano-titanium dioxide enhances its interfacial bonding with resin and bio-based components, reducing the tendency of powder agglomeration. At the same time, controlling the upper limit of the overall particle size to within 5 μm ensures that the powder will not puncture the membrane and form leakage points due to excessive size in the ultrathin (approximately 0.02 mm) functional membrane, which helps to maintain a hydrostatic pressure exceeding 15000 mm.

[0054] In this embodiment, the bottom layer is a warp-knitted fleece fabric with a short pile structure and a weight of 60-70 g / m². The warp-knitted fleece structure of the bottom layer ensures warmth (by locking in air layers for enhanced warmth) and also provides excellent anti-snagging and anti-pilling properties. The weight range of 60-70 g / m² provides an ideal base thickness for the heat-sealing process: too light a weight results in insufficient fullness and warmth, while too heavy a weight leads to insufficient pressure during sealing. Combining the inherent dimensional stability of the warp-knitted structure with the short pile structure, this approach solves the industry problem of poor adhesive bonding and water seepage caused by the excessively thick pile and loose structure of traditional fleece (weft-knitted, long-pile) during sealing, achieving a balance between warmth and processing reliability. Further optimizing the bottom layer weight to 65 g / m² is a preferred embodiment, ensuring warmth without compromising the heat-sealing effect.

[0055] In this embodiment, the surface layer is a woven fabric of fully matte polyester filament with a specific specification (150D / 144F). Fabrics woven from this specification of yarn, while ensuring sufficient abrasion resistance and tear resistance, possess an excellent matte texture and soft feel through a fully matte finish and fine texture, enhancing the garment's appearance and wearing comfort, making it more suitable for the application requirements of high-end outdoor clothing.

[0056] In this embodiment, the thickness of the biomass waterproof, breathable, and heat-generating membrane is 0.02mm ± 0.005mm. The membrane thickness is sufficient to accommodate 5% powder and form a continuous, defect-free microporous structure, ensuring the full utilization of the waterproof and breathable function; at the same time, it is thin enough to allow the final three-layer composite fabric to maintain excellent softness and drape.

[0057] An outdoor protective garment, made from the aforementioned bio-based heat-retaining composite fabric, comprehensively inherits all the functional advantages of the fabric. The final product exhibits excellent wind and water resistance, high moisture permeability and comfort, active warmth retention, and reliable seam sealing in actual use, meeting the stringent performance requirements of high-end outdoor sports.

[0058] The present application will be further described below with reference to the embodiments, but the scope of protection of the present application is not limited thereto.

[0059] Example 1

[0060] 1. Raw material preparation and pretreatment

[0061] Intermediate layer membrane raw materials:

[0062] Matrix resin: Commercially available liquid polyether permeable polyurethane resin (PU resin) with a solid content of 30% was selected. In this embodiment, 75 kg of the resin solids were prepared based on the dry matter (solid component) mass.

[0063] Bio-based ingredients: Prepare 20 kg of bio-based polyols derived from castor oil.

[0064] Inorganic exothermic powder: Prepare 5 kg of composite powder made by pre-mixing zirconium oxide (ZrO2) and titanium oxide (TiO2) in a mass ratio of 3:2. The volume average particle size of the composite powder is approximately 3 μm.

[0065] Surface layer: Prepare a 58-inch wide polyester woven fabric (spring spun). Both the warp and weft yarns are 150D / 144F fully dull polyester filaments, with warp and weft densities of 87 threads / inch and 80 threads / inch, respectively.

[0066] Bottom layer: Prepare a warp-knitted fleece base fabric with a weight of 65g / m².

[0067] Adhesives for lamination: Prepare polyurethane reactive (PUR) hot melt adhesives suitable for textile lamination.

[0068] 2. Preparation of biomass waterproof and breathable heating membrane

[0069] Ingredients and Mixing: In a mixing vessel equipped with an adjustable speed stirrer and a temperature-controlled jacket, first add the calculated mass of 30% solids-content polyether permeable PU resin liquid (equivalent to 75 kg dry weight). Start low-speed stirring and slowly and evenly pour in 20 kg of castor oil bio-based components. After the two are initially mixed, gradually add 5 kg of pre-dried zirconium oxide / titanium oxide composite heating powder.

[0070] High-speed homogenization: After all materials have been added, increase the stirring speed to 800 rpm and continue stirring at room temperature for 30 minutes. Control the final slurry viscosity to approximately 8000 centipoise (cps).

[0071] Coating and Film Formation: The uniformly mixed slurry is transferred to the feed trough of the release paper coating machine. A smooth-surfaced release paper is selected as the substrate. The wet film coating amount is controlled at 180 g / m². The slurry is evenly coated on the release paper, forming a continuous wet film layer.

[0072] Stepped baking and curing: The release paper carrying the wet film immediately enters a continuous drying tunnel divided into five independent temperature zones. The temperature settings for each zone of the drying tunnel are as follows: Zone 1 80℃, Zone 2 100℃, Zone 3 120℃, Zone 4 150℃, and Zone 5 150℃. The total residence time of the wet film in the drying tunnel is approximately 5 minutes.

[0073] Winding and Curing: After complete curing in the drying tunnel, the membrane is peeled off from the release paper to obtain the biomass waterproof, breathable, and heat-generating film. Its average thickness is 0.02 mm. This functional film is then wound up and placed in a curing chamber for 24 hours at a relative humidity of 60%-70% for later use.

[0074] 3. Interlayer composite

[0075] The film is laminated with 150D polyester fabric using PUR adhesive (9g / m², 120℃) and cured at 65%RH for 24 hours; then laminated again with 65g / m² warp-knitted fleece base fabric, and cured at 65%RH for 24 hours to obtain the final fabric.

[0076] 4. Performance Testing:

[0077] hydrostatic pressure: 15200 mm

[0078] Moisture permeability: 7200 g / (m²·24h)

[0079] Thermal storage performance (GB / T 8319-2019): Maximum temperature rise ≥ 8.0 K

[0080] Peel strength: ≥7 N / 2cm

[0081] Water wash resistance (after 5 washes): hydrostatic pressure maintained at ≥6000 mm, moisture permeability ≥7000 g / (m²·24h), heat storage temperature rise value ≥6.0K.

[0082] Example 2 (Powder Variable)

[0083] The total amount of composite heating powder was changed to 3% (i.e., 77% matrix resin, 20% bio-based, and 3% powder), and the rest was the same as in Example 1.

[0084] Test results:

[0085] hydrostatic pressure: 15500mm

[0086] Moisture permeability: 7500 g / (m²·24h)

[0087] Thermal storage performance (GB / T 8319-2019): Maximum temperature rise ≥ 6.0K

[0088] The decrease in heat storage performance indicates that a 5% powder addition achieves a better balance between heat storage and waterproofing / breathability.

[0089] Example 3 (Bio-based Variables)

[0090] The amount of bio-based component added was changed to 30% (i.e., 65% matrix resin, 30% bio-based, and 5% powder), and the rest was the same as in Example 1.

[0091] Test results: The hydrostatic pressure did not change much, but the moisture permeability decreased significantly. When the bio-based content increased, the corresponding moisture permeability decreased to 6800 g / (m²·24h), indicating that as the bio-based content increased, the corresponding moisture permeability decreased. However, the addition of 20% bio-based content can better balance the hydrostatic pressure and moisture permeability of the membrane material while ensuring environmental protection.

[0092] Comparative Example 1 (Traditional Membrane Material)

[0093] A conventional petroleum-based TPU film without bio-based or special heating powders was used, with the top and bottom layers being the same as in Example 1.

[0094] Test results:

[0095] hydrostatic pressure: 14000 mm

[0096] Moisture permeability: 6000 g / (m²·24h)

[0097] The absence of heat storage function demonstrates the significant advantages of the functional membrane of this invention in improving overall performance.

[0098] Comparative Example 2 (Traditional Base Layer)

[0099] Ordinary knitted weft-knitted fleece (approximately 130g / m²) was used instead of warp-knitted fleece base fabric, and the rest was the same as in Example 1.

[0100] Test results: The fabric exhibited poor anti-snagging and pilling properties, showing signs of fuzzing after repeated friction, and there was a risk of water leakage at the heat-sealed seam. This directly verifies the necessity of using a specific warp-knitted fleece fabric to solve the sealing problem in garment processing.

[0101] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A bio-based thermal storage composite fabric, employing a layered composite structure, comprising a surface layer, a middle layer, and a bottom layer; characterized in that, The intermediate layer is a biomass waterproof and breathable heating membrane, the raw materials of which include, by mass percentage: 75% polyether breathable polyurethane resin, 20% bio-based components derived from castor oil, and 5% inorganic heating powder composed of zirconium oxide and titanium oxide.

2. The bio-based heat storage composite fabric of claim 1, wherein, In the inorganic exothermic powder, the mass ratio of zirconium oxide to titanium oxide is 3:

2.

3. The bio-based heat storage composite fabric according to claim 1 or 2, wherein, The inorganic heating powder is composed of micron-sized zirconium oxide powder and nano-sized titanium oxide powder.

4. The bio-based heat accumulating composite fabric of claim 3, wherein the bio-based heat accumulating composite fabric is characterized by, The titanium oxide component in the inorganic heating powder consists of nanoparticles with an average particle size of less than 100 nm, and the overall average particle size of the inorganic heating powder is 1-5 μm.

5. The bio-based heat accumulating composite fabric of claim 1, wherein the bio-based heat accumulating composite fabric is characterized by, The bottom layer is a warp-knitted fleece fabric with a weight of 60-70 g / m² and a short pile structure.

6. The bio-based heat accumulating composite fabric of claim 5, wherein the bio-based heat accumulating composite fabric is characterized by, The weight of the bottom layer is 65 g / m².

7. The bio-based heat accumulating composite fabric of claim 1, wherein the bio-based heat accumulating composite fabric is characterized by, The surface layer is a woven fabric made of fully dull polyester filaments with warp and weft yarns of 150D / 144F.

8. The bio-based heat accumulating composite fabric of claim 1, wherein, The thickness of the biomass waterproof and breathable heating membrane is 0.02mm ± 0.005mm.

9. A method for preparing a bio-based thermal storage composite fabric, for preparing a bio-based thermal storage composite fabric according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Preparation of biomass waterproof and breathable heat-generating membrane: The polyether breathable polyurethane resin with a solid content of 30%, the bio-based component and the inorganic heat-generating powder are mixed to form a slurry with a viscosity of 8000±500cps. The slurry is coated on release paper with a coating amount of 180±10g / m², and then cured by step baking to form the biomass waterproof and breathable heat-generating membrane. S2. First lamination: The biomass waterproof and breathable heat-generating membrane is spot-bonded to the surface layer using polyurethane reactive hot melt adhesive; S3. Second lamination: The fabric after lamination in step S2 is spot-bonded to the underlying layer using polyurethane reactive hot melt adhesive.

10. The method for preparing a bio-based thermal storage composite fabric according to claim 9, characterized in that, The stepped baking and curing process involves temperatures of 80℃, 100℃, 120℃, 150℃, and 150℃ in sequence.

11. A method for preparing a bio-based thermal storage composite fabric according to claim 9 or 10, characterized in that, After step S2 and / or step S3, a curing step is also included, which is carried out in an environment with a relative humidity of 60%-70% for 24 hours.

12. An outdoor protective garment, characterized in that Made from a bio-based thermal storage composite fabric as described in any one of claims 1 to 8.