A foamed material containing biologically active crystals, its method of manufacture and use in a mattress

Abstract

The application discloses a kind of foamed material containing bioactive crystal and its preparation method and application in mattress, it is related to polyurethane foamed material technical field.The method includes with porous mineral as carrier, surface and pore load phosphorus nitrogen series flame retardant, and outer coating inorganic flame-retardant shell, and the core-shell structure flame-retardant filler is prepared;Provide surface grafting with active group that can react with isocyanate group's reinforcing fiber;Polyol, isocyanate, foaming agent, flame-retardant filler, reinforcing fiber, calcium carbonate whisker, mica powder, bioactive crystal powder, catalyst and uniform foaming agent are mixed, and through foaming reaction and solidification forming, and the target product is prepared.The application is by constructing core-shell flame-retardant filler and reactive reinforcing fiber composite system, and simultaneously introducing whisker, mica and bioactive crystal, and give foamed material gradient flame-retardant, efficient reinforcing and the comprehensive function of bioactivity.

Description

Technical Field

[0001] This invention relates to the field of polyurethane foam materials technology, specifically to a foam material containing bioactive crystals, its preparation method, and its application in mattresses. Background Technology

[0002] Polyurethane foam materials have been widely used in mattress manufacturing due to their excellent elasticity, pressure-reducing cushioning, and ease of molding and processing. With the continuous penetration of consumption upgrades and healthy living concepts, the market has placed higher demands on the comprehensive performance of mattress foam materials: on the one hand, consumers expect mattress materials to have a long service life and structural stability, meaning that the foam is not easily torn or damaged during long-term use, handling, and turning; on the other hand, fire safety standards for mattress products in various countries are becoming increasingly stringent, requiring foam materials to have reliable flame-retardant properties to reduce fire risks. Furthermore, incorporating natural bioactive crystal powders (such as tourmaline and Bianstone, minerals with far-infrared radiation and negative ion release functions) into the foam to endow the mattress with health benefits has gradually become a hot area for market differentiation. However, existing technologies face significant technical difficulties in simultaneously meeting these multiple functional requirements. Traditional flame-retardant solutions often employ the direct physical blending of halogenated or phosphorus-based flame retardants into the foaming system. While this approach can improve flame-retardant performance to some extent, the poor interfacial compatibility between the flame retardant and the polyurethane matrix, and high addition levels often lead to a significant deterioration in the mechanical properties of the foam, especially a substantial decrease in tear strength. Simply adding chopped fibers to the system to enhance tear resistance has limited reinforcing efficiency because the fibers are easily pulled out under stress due to the lack of effective chemical bonding between the fibers and the matrix. More problematic is that when flame-retardant modification and mechanical reinforcement are performed simultaneously, the functional components introduced by the two modifications often interfere with each other—for example, the presence of a large number of rigid flame-retardant filler particles can disrupt the uniformity of the cell structure, thus weakening the reinforcing effect of the reinforcing fibers. Therefore, there is currently a lack of an integrated preparation method that can systematically solve the above contradictions, enabling the foamed material to simultaneously achieve excellent flame-retardant properties and high tear resistance, while also incorporating the functionality of bioactive crystal powder. Summary of the Invention

[0003] The purpose of this invention is to provide a foaming material containing bioactive crystals and its preparation method, so as to solve the technical problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Provide a flame-retardant filler with a core-shell structure, wherein the flame-retardant filler uses porous minerals as a carrier, and phosphorus-nitrogen flame retardants are loaded on its surface and in its pores, and an inorganic flame-retardant shell is coated on its exterior. (2) Provide reinforcing fibers, wherein the surface of the reinforcing fibers is grafted with active groups capable of reacting with isocyanate groups; (3) Mix the polyol component, isocyanate component, foaming agent, flame retardant filler, reinforcing fiber, calcium carbonate whiskers, mica powder, bioactive crystal powder, catalyst and foam leveling agent, and carry out foaming reaction and curing to obtain the product.

[0005] Preferably, the preparation process of the flame-retardant filler with a core-shell structure in step (1) includes: The porous mineral is activated to obtain an activated mineral carrier; The phosphorus-nitrogen flame retardant is formulated into a slurry or solution, and the activated mineral carrier is impregnated in the slurry or solution under negative pressure or vacuum conditions to achieve the loading of the flame retardant into the interior and surface of the mineral pores. The inorganic flame-retardant shell layer is formed by depositing metal hydroxides on the surface of a mineral carrier loaded with phosphorus and nitrogen flame retardants through in-situ chemical precipitation.

[0006] Preferably, the porous mineral is at least one of sepiolite, attapulgite, or wollastonite; The phosphorus-nitrogen flame retardant is at least one of ammonium polyphosphate, melamine polyphosphate, or melamine cyanurate. The inorganic flame-retardant shell is aluminum hydroxide or magnesium hydroxide.

[0007] Preferably, the activation treatment is an acid activation treatment, specifically performed as follows: Natural sepiolite powder was added to a hydrochloric acid solution with a mass concentration of 8-12%, and stirred at 60-70℃ for 1.5-2.5 hours at a solid-liquid ratio of 1:(5-8) g / mL. After filtration, washing with water and drying, activated sepiolite was obtained. The mass ratio of ammonium polyphosphate to activated mineral carrier is (0.6–1.5):1.

[0008] Preferably, the preparation process of the reinforcing fiber in step (2) includes: Inorganic fibers are subjected to alkaline washing and activation treatment to expose the silanol groups on the fiber surface; The inorganic fibers after alkali washing are grafted with a silane coupling agent containing the active groups, so that the active groups are anchored to the fiber surface through siloxane bonds.

[0009] Preferably, the inorganic fiber is chopped basalt fiber or glass fiber; the active group is a primary amine group or a secondary amine group; and the silane coupling agent is an aminosilane coupling agent.

[0010] Preferably, the alkaline washing and activation process is specifically operated as follows: The inorganic fibers are added to a sodium hydroxide solution with a mass concentration of 3-5% and stirred and soaked at 60-70°C for 0.5-1.5 hours; after filtration, washing and drying, activated fibers are obtained. The mass ratio of the activated fiber to the aminosilane coupling agent is 1:(0.1-0.3).

[0011] Preferably, the polyol component includes polyether polyols and polymer polyols; The isocyanate component is toluene diisocyanate; The foaming agent is water; The catalysts include amine catalysts and organotin catalysts; The foaming agent is an open-cell polyether modified silicone oil; The bioactive crystal powder is made by mixing and grinding tourmaline powder, bian stone powder and maifan stone powder in equal mass ratio; The weight ratio of each component in step (3) is as follows: The composition includes 55-65 parts polyether polyol, 15-25 parts polymer polyol, 40-55 parts toluene diisocyanate, 3-5 parts water, 10-18 parts of the flame retardant filler, 2-6 parts of the reinforcing fiber, 1-3 parts calcium carbonate whiskers, 0.5-1.5 parts mica powder, 5-10 parts bioactive crystal powder, 0.5-1.0 parts amine catalyst, 0.05-0.15 parts organotin catalyst, and 0.8-1.5 parts open-cell polyether modified silicone oil.

[0012] A foaming material containing bioactive crystals is prepared by the method described above.

[0013] Application of a foam material containing bioactive crystals in mattresses.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. By constructing a three-layer functionalized filler architecture consisting of a sepiolite mineral framework supporting a phosphorus-nitrogen flame-retardant layer and an outer aluminum hydroxide shell, a gradient flame-retardant mechanism with sequential responses from the outside to the inside is achieved: the outer aluminum hydroxide layer absorbs heat and dehydrates upon contact with fire, generating water vapor, which forms a non-combustible gas dilution zone on the material surface, reducing oxygen and transforming into an alumina thermal insulation barrier; the middle phosphorus-nitrogen flame-retardant component is catalyzed by heat to generate a dense, expanded char layer, while simultaneously blocking the reaction between external heat radiation and internal combustible gases; the inner sepiolite framework, with its extremely low thermal conductivity and high-temperature structural stability, supports the char layer, preventing it from cracking and collapsing. This triple mechanism, relaying and connecting across the temperature range and nested within the spatial structure, forms an organically synergistic protective system, far superior to the individual efforts of simple blending of flame-retardant components, resulting in a fundamental improvement in the flame-retardant effect of the foamed material.

[0015] 2. Short-cut basalt fibers, after alkali washing activation and silane coupling treatment, form an active interface layer on their surface that can covalently bond with the polyurethane matrix. During foaming, the fibers are anchored in situ to the cross-linked network by the driving force of the reaction, transforming from heterogeneous inclusions into chemically bonded structural load-bearing components. When the material is torn, the fibers crossing the crack surface generate a bridging effect, efficiently transferring stress to the high-strength fibers through the covalent interface. Through elastic stretching, fracture, and interfacial friction pull-out, a large amount of fracture energy is consumed. At the same time, the randomly oriented short-cut fibers form a crack interception network in three-dimensional space, which forces the crack to repeatedly deflect and branch regardless of the tear direction, transforming the single through-type failure into multiple detour energy-consuming paths, resulting in a statistically significant and comprehensive enhancement of tear resistance.

[0016] 3. To address the bottleneck caused by uneven thinning of cell walls and microcracks resulting from high levels of flame-retardant mineral fillers, which weakens the fiber reinforcement effect, calcium carbonate whiskers and mica powder are simultaneously introduced to compensate for the cell structure. Whiskers, with their high aspect ratio, are preferentially arranged along the tensile direction in the cell walls and edges, acting like miniature steel bars reinforcing weak areas, inhibiting crack initiation and dispersing stress in the initial stage. Mica sheets form a layered barrier in the cell structure, forcing attempting cracks to repeatedly deflect and separate between layers, significantly consuming fracture surface energy. The two work synergistically at different stages of crack initiation and propagation, effectively compensating for the damage to the uniformity of the cell structure caused by rigid flame-retardant fillers. This ensures that the material can still fully exert the tear-resistant reinforcement effect of the fibers while achieving sufficient flame retardancy, thus overcoming the toughening bottleneck. Attached Figure Description

[0017] Figure 1 This is a low-magnification SEM image of the foam material containing bioactive crystals prepared in Example 1 of the present invention.

[0018] Figure 2 This is a high-magnification SEM image of the foam material containing bioactive crystals prepared in Example 1 of the present invention.

[0019] Figure 3 The image shows the XRD pattern of the foam material containing bioactive crystals prepared in Example 1 of this invention. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1

[0022] A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Add natural sepiolite powder (200-300 mesh) to a 11% hydrochloric acid solution at a solid-liquid ratio of 1:7 g / mL and stir at 65°C for 2 hours. Filter and wash with deionized water until the pH of the filtrate is 7. Dry at 105°C for 4 hours to obtain activated sepiolite. Grind ammonium polyphosphate (APP, degree of polymerization n≥100) into an ultrafine powder of more than 2000 mesh, add it to deionized water, and disperse it with an ultrasonic power of 400W for 25 minutes to prepare an APP suspension slurry with a solid content of 25%. Add activated sepiolite to the APP slurry at a mass ratio of 1:1.2 between activated sepiolite and ammonium polyphosphate. Place it in a vacuum drying oven and impregnate it at a vacuum of -0.07MPa and a temperature of 30°C for 1.5 hours. Remove and filter to remove excess slurry. Dry at 50°C to constant weight to obtain APP-loaded sepiolite. APP-loaded sepiolite was added to a 12% aluminum sulfate solution at a mass ratio of 1:5 and stirred and dispersed evenly at 45°C. Then, a 12% sodium hydroxide solution was slowly added dropwise at a rate of 1.5 mL / min to control the pH of the reaction system to eventually stabilize at 8.0. The reaction was continued at 45°C for 1.5 h to allow aluminum hydroxide to be deposited in situ on the surface of the APP-loaded sepiolite to form a dense coating layer. The mixture was filtered, rinsed three times with deionized water, and dried at 85°C for 7 h to obtain the flame-retardant modified filler.

[0023] (2) Take short-cut basalt fibers (3-5 mm in length and 10-15 μm in diameter), add them to a sodium hydroxide solution with a mass concentration of 4.5%, and the solid-liquid ratio of the fiber to the sodium hydroxide solution is 1:12 g / mL. Stir and soak at 65℃ for 1 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105℃ for 3 h to obtain activated basalt fibers. γ-aminopropyltriethoxysilane (KH-550) was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to prepare a 2% (w / w) silane coupling agent hydrolysate. The pH was adjusted to 4.5 with acetic acid, and the solution was pre-hydrolyzed at room temperature for 25 min. Activated basalt fibers were added to the silane solution at a mass ratio of 1:0.25 to γ-aminopropyltriethoxysilane. The mixture was stirred at 55 °C for 2.5 h. After filtration, the solution was washed once with anhydrous ethanol and dried at 108 °C for 2.5 h to obtain amino-functionalized basalt fibers.

[0024] (3) By weight, weigh 63 parts of polyether polyol 330N (functionality 3, hydroxyl value 56mgKOH / g), 22 parts of polymer polyol POP (grafted SAN modified, functionality 3, hydroxyl value 28mgKOH / g, solid content about 40%), 52 parts of toluene diisocyanate (TDI-80), 4.5 parts of water, 16 parts of flame retardant modified filler, 5 parts of amino-functionalized basalt fiber, 2.5 parts of calcium carbonate whiskers (diameter 0.5~2μm, length 5~20μm), 1.2 parts of mica powder (800 mesh white mica powder), 9 parts of bioactive crystal powder (tourmaline powder, Bian stone powder and Maifan stone powder mixed and ground in equal mass ratio, particle size 400 mesh), 0.9 parts of triethanolamine, 0.12 parts of dibutyltin dilaurate, and 1.3 parts of open-cell polyether modified silicone oil. First, amino-functionalized basalt fibers were added to a portion of polyether polyol and pre-dispersed at 600 rpm for 4 minutes to prepare a fiber masterbatch. Calcium carbonate whiskers and mica powder were added to another portion of polyether polyol and pre-dispersed at 2500 rpm for 8 minutes using a high-speed disperser to prepare a filler masterbatch. The fiber masterbatch, filler masterbatch, and other components (except TDI) were then added to a mixing container and mixed at 1000 rpm for 80 seconds at 50°C to form a uniform premix of component A. Then, TDI (component B) was added and rapidly mixed at 2500 rpm for 8 seconds until homogeneous. The mixture was immediately poured into a mattress mold preheated to 52°C. The milky whitening time was approximately 10 seconds, and the gelation time was approximately 100 seconds. The mixture was kept in the mold for another 6 minutes until the foam had sufficient green strength before demolding. The final product was cured at room temperature for 36 hours.

[0025] Example 2

[0026] A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Add natural sepiolite powder (200-300 mesh) to a 9% hydrochloric acid solution at a solid-liquid ratio of 1:6 g / mL and stir at 65°C for 2 hours. Filter and wash with deionized water until the pH of the filtrate is 7. Dry at 105°C for 4 hours to obtain activated sepiolite. Grind ammonium polyphosphate (APP, degree of polymerization n≥100) into an ultrafine powder of more than 2000 mesh, add it to deionized water, and disperse it with an ultrasonic power of 400W for 25 minutes to prepare an APP suspension slurry with a solid content of 25%. Add activated sepiolite to the APP slurry at a mass ratio of 1:0.8 between activated sepiolite and ammonium polyphosphate. Place it in a vacuum drying oven and impregnate it at a vacuum of -0.07MPa and a temperature of 30°C for 1.5 hours. Remove and filter to remove excess slurry. Dry at 50°C to constant weight to obtain APP-loaded sepiolite. APP-loaded sepiolite was added to a 12% aluminum sulfate solution at a mass ratio of 1:5 and stirred and dispersed evenly at 45°C. Then, a 12% sodium hydroxide solution was slowly added dropwise at a rate of 1.5 mL / min to control the pH of the reaction system to eventually stabilize at 8.0. The reaction was continued at 45°C for 1.5 h to allow aluminum hydroxide to be deposited in situ on the surface of the APP-loaded sepiolite to form a dense coating layer. The mixture was filtered, rinsed three times with deionized water, and dried at 85°C for 7 h to obtain the flame-retardant modified filler.

[0027] (2) Take short-cut basalt fibers (3-5 mm in length and 10-15 μm in diameter), add them to a sodium hydroxide solution with a mass concentration of 3.5%, and the solid-liquid ratio of the fiber to the sodium hydroxide solution is 1:12 g / mL. Stir and soak at 65℃ for 1 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105℃ for 3 h to obtain activated basalt fibers. γ-aminopropyltriethoxysilane (KH-550) was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to prepare a 2% (w / w) silane coupling agent hydrolysate. The pH was adjusted to 4.5 with acetic acid, and the solution was pre-hydrolyzed at room temperature for 25 min. Activated basalt fibers were added to the silane solution at a mass ratio of 1:0.15 to γ-aminopropyltriethoxysilane. The mixture was stirred at 55 °C for 2.5 h. After filtration, the solution was washed once with anhydrous ethanol and dried at 108 °C for 2.5 h to obtain amino-functionalized basalt fibers.

[0028] (3) By weight, weigh 58 parts of polyether polyol 330N (functionality 3, hydroxyl value 56mgKOH / g), 18 parts of polymer polyol POP (grafted SAN modified, functionality 3, hydroxyl value 28mgKOH / g, solid content about 40%), 45 parts of toluene diisocyanate (TDI-80), 3.5 parts of water, 12 parts of flame retardant modified filler, 3 parts of amino-functionalized basalt fiber, 1.5 parts of calcium carbonate whiskers (diameter 0.5~2μm, length 5~20μm), 0.8 parts of mica powder (800 mesh white mica powder), 6 parts of bioactive crystal powder (tourmaline powder, Bian stone powder and Maifan stone powder mixed and ground in equal mass ratio, particle size 400 mesh), 0.6 parts of triethanolamine, 0.08 parts of dibutyltin dilaurate, and 0.9 parts of open-cell polyether modified silicone oil. First, amino-functionalized basalt fibers were added to a portion of polyether polyol and pre-dispersed at 600 rpm for 4 minutes to prepare a fiber masterbatch. Calcium carbonate whiskers and mica powder were added to another portion of polyether polyol and pre-dispersed at 2500 rpm for 8 minutes using a high-speed disperser to prepare a filler masterbatch. The fiber masterbatch, filler masterbatch, and other components (except TDI) were then added to a mixing container and mixed at 1000 rpm for 80 seconds at 50°C to form a uniform premix of component A. Then, TDI (component B) was added and rapidly mixed at 2500 rpm for 8 seconds until homogeneous. The mixture was immediately poured into a mattress mold preheated to 52°C. The milky whitening time was approximately 10 seconds, and the gelation time was approximately 100 seconds. The mixture was kept in the mold for another 6 minutes until the foam had sufficient green strength before demolding. The final product was cured at room temperature for 36 hours.

[0029] Example 3

[0030] A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Add natural sepiolite powder (200-300 mesh) to a 10% hydrochloric acid solution at a solid-liquid ratio of 1:6.5 g / mL and stir at 65°C for 2 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105°C for 4 h to obtain activated sepiolite. Grind ammonium polyphosphate (APP, degree of polymerization n≥100) into an ultrafine powder of more than 2000 mesh, add it to deionized water, disperse it with ultrasonic power of 400W for 25 min, and prepare an APP suspension slurry with a solid content of 25%; add activated sepiolite to the APP slurry at a mass ratio of 1:1 between activated sepiolite and ammonium polyphosphate, place it in a vacuum drying oven, and impregnate it at a vacuum degree of -0.07MPa and a temperature of 30°C for 1.5 h; remove it, filter to remove excess slurry, and dry it at 50°C to constant weight to obtain APP-loaded sepiolite. APP-loaded sepiolite was added to a 12% aluminum sulfate solution at a mass ratio of 1:5 and stirred and dispersed evenly at 45°C. Then, a 12% sodium hydroxide solution was slowly added dropwise at a rate of 1.5 mL / min to control the pH of the reaction system to eventually stabilize at 8.0. The reaction was continued at 45°C for 1.5 h to allow aluminum hydroxide to be deposited in situ on the surface of the APP-loaded sepiolite to form a dense coating layer. The mixture was filtered, rinsed three times with deionized water, and dried at 85°C for 7 h to obtain the flame-retardant modified filler.

[0031] (2) Take short-cut basalt fibers (3-5 mm in length and 10-15 μm in diameter), add them to a sodium hydroxide solution with a mass concentration of 4%, and the solid-liquid ratio of the fiber to the sodium hydroxide solution is 1:12 g / mL. Stir and soak at 65℃ for 1 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105℃ for 3 h to obtain activated basalt fibers. γ-aminopropyltriethoxysilane (KH-550) was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to prepare a 2% (w / w) silane coupling agent hydrolysate. The pH was adjusted to 4.5 with acetic acid, and the solution was pre-hydrolyzed at room temperature for 25 min. Activated basalt fibers were added to the silane solution at a mass ratio of 1:0.2 to γ-aminopropyltriethoxysilane. The mixture was stirred at 55 °C for 2.5 h. After filtration, the solution was washed once with anhydrous ethanol and dried at 108 °C for 2.5 h to obtain amino-functionalized basalt fibers.

[0032] (3) By weight, weigh 60 parts of polyether polyol 330N (functionality 3, hydroxyl value 56mgKOH / g), 20 parts of polymer polyol POP (grafted SAN modified, functionality 3, hydroxyl value 28mgKOH / g, solid content about 40%), 50 parts of toluene diisocyanate (TDI-80), 4 parts of water, 14 parts of flame retardant modified filler, 4 parts of amino-functionalized basalt fiber, 2 parts of calcium carbonate whiskers (diameter 0.5~2μm, length 5~20μm), 1 part of mica powder (800 mesh white mica powder), 7 parts of bioactive crystal powder (tourmaline powder, Bian stone powder and Maifan stone powder mixed and ground in equal mass ratio, particle size 400 mesh), 0.7 parts of triethanolamine, 0.1 parts of dibutyltin dilaurate, and 1 part of open-cell polyether modified silicone oil. First, amino-functionalized basalt fibers were added to a portion of polyether polyol and pre-dispersed at 600 rpm for 4 minutes to prepare a fiber masterbatch. Calcium carbonate whiskers and mica powder were added to another portion of polyether polyol and pre-dispersed at 2500 rpm for 8 minutes using a high-speed disperser to prepare a filler masterbatch. The fiber masterbatch, filler masterbatch, and other components (except TDI) were then added to a mixing container and mixed at 1000 rpm for 80 seconds at 50°C to form a uniform premix of component A. Then, TDI (component B) was added and rapidly mixed at 2500 rpm for 8 seconds until homogeneous. The mixture was immediately poured into a mattress mold preheated to 52°C. The milky whitening time was approximately 10 seconds, and the gelation time was approximately 100 seconds. The mixture was kept in the mold for another 6 minutes until the foam had sufficient green strength before demolding. The final product was cured at room temperature for 36 hours.

[0033] Example 4

[0034] A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Add natural sepiolite powder (200-300 mesh) to a 12% hydrochloric acid solution at a solid-liquid ratio of 1:8 g / mL and stir at 70°C for 2.5 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105°C for 4 h to obtain activated sepiolite. Grind ammonium polyphosphate (APP, degree of polymerization n≥100) into an ultrafine powder of more than 2000 mesh, add it to deionized water, disperse it with ultrasonic power of 400W for 25 min, and prepare an APP suspension slurry with a solid content of 25%; add activated sepiolite to the APP slurry at a mass ratio of 1:1.5 of activated sepiolite to ammonium polyphosphate, place it in a vacuum drying oven, and impregnate it at a vacuum degree of -0.07MPa and a temperature of 30°C for 1.5 h; remove it, filter to remove excess slurry, and dry at 50°C to constant weight to obtain APP-loaded sepiolite. APP-loaded sepiolite was added to a 12% aluminum sulfate solution at a mass ratio of 1:5 and stirred and dispersed evenly at 45°C. Then, a 12% sodium hydroxide solution was slowly added dropwise at a rate of 1.5 mL / min to control the pH of the reaction system to eventually stabilize at 8.0. The reaction was continued at 45°C for 1.5 h to allow aluminum hydroxide to be deposited in situ on the surface of the APP-loaded sepiolite to form a dense coating layer. The mixture was filtered, rinsed three times with deionized water, and dried at 85°C for 7 h to obtain the flame-retardant modified filler.

[0035] (2) Take short-cut basalt fibers (3-5 mm in length and 10-15 μm in diameter), add them to a 5% sodium hydroxide solution, with a solid-liquid ratio of 1:12 g / mL between the fibers and the sodium hydroxide solution, and stir and soak at 70°C for 1.5 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105°C for 3 h to obtain activated basalt fibers. γ-aminopropyltriethoxysilane (KH-550) was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to prepare a 2% (w / w) silane coupling agent hydrolysate. The pH was adjusted to 4.5 with acetic acid, and the solution was pre-hydrolyzed at room temperature for 25 min. Activated basalt fibers were added to the silane solution at a mass ratio of 1:0.3 to γ-aminopropyltriethoxysilane. The mixture was stirred at 55 °C for 2.5 h. After filtration, the solution was washed once with anhydrous ethanol and dried at 108 °C for 2.5 h to obtain amino-functionalized basalt fibers.

[0036] (3) By weight, weigh 65 parts of polyether polyol 330N (functionality 3, hydroxyl value 56mgKOH / g), 25 parts of polymer polyol POP (grafted SAN modified, functionality 3, hydroxyl value 28mgKOH / g, solid content about 40%), 55 parts of toluene diisocyanate (TDI-80), 5 parts of water, 18 parts of flame retardant modified filler, 6 parts of amino-functionalized basalt fiber, 3 parts of calcium carbonate whiskers (diameter 0.5~2μm, length 5~20μm), 1.5 parts of mica powder (800 mesh white mica powder), 10 parts of bioactive crystal powder (tourmaline powder, Bian stone powder and Maifan stone powder mixed and ground in equal mass ratio, particle size 400 mesh), 1 part of triethanolamine, 0.15 parts of dibutyltin dilaurate, and 1.5 parts of open-cell polyether modified silicone oil. First, amino-functionalized basalt fibers were added to a portion of polyether polyol and pre-dispersed at 600 rpm for 4 minutes to prepare a fiber masterbatch. Calcium carbonate whiskers and mica powder were added to another portion of polyether polyol and pre-dispersed at 2500 rpm for 8 minutes using a high-speed disperser to prepare a filler masterbatch. The fiber masterbatch, filler masterbatch, and other components (except TDI) were then added to a mixing container and mixed at 1000 rpm for 80 seconds at 50°C to form a uniform premix of component A. Then, TDI (component B) was added and rapidly mixed at 2500 rpm for 8 seconds until homogeneous. The mixture was immediately poured into a mattress mold preheated to 52°C. The milky whitening time was approximately 10 seconds, and the gelation time was approximately 100 seconds. The mixture was kept in the mold for another 6 minutes until the foam had sufficient green strength before demolding. The final product was cured at room temperature for 36 hours.

[0037] Example 5

[0038] A method for preparing a foaming material containing bioactive crystals includes the following steps: (1) Add natural sepiolite powder (200-300 mesh) to a hydrochloric acid solution with a mass concentration of 8%, and stir at 60°C for 1.5 h at a solid-liquid ratio of 1:5 g / mL. Filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105°C for 4 h to obtain activated sepiolite. Grind ammonium polyphosphate (APP, degree of polymerization n≥100) into an ultrafine powder of more than 2000 mesh, add to deionized water, and disperse with ultrasonic power of 400W for 25 min to prepare an APP suspension slurry with a solid content of 25%. Add activated sepiolite to the APP slurry, with a mass ratio of activated sepiolite to ammonium polyphosphate of 1:0.6. Place in a vacuum drying oven and impregnate at a vacuum degree of -0.07MPa and a temperature of 30°C for 1.5 h. Remove, filter to remove excess slurry, and dry at 50°C to constant weight to obtain APP-loaded sepiolite. APP-loaded sepiolite was added to a 12% aluminum sulfate solution at a mass ratio of 1:5 and stirred and dispersed evenly at 45°C. Then, a 12% sodium hydroxide solution was slowly added dropwise at a rate of 1.5 mL / min to control the pH of the reaction system to eventually stabilize at 8.0. The reaction was continued at 45°C for 1.5 h to allow aluminum hydroxide to be deposited in situ on the surface of the APP-loaded sepiolite to form a dense coating layer. The mixture was filtered, rinsed three times with deionized water, and dried at 85°C for 7 h to obtain the flame-retardant modified filler.

[0039] (2) Take short-cut basalt fibers (3-5 mm in length and 10-15 μm in diameter), add them to a 3% sodium hydroxide solution, with a solid-liquid ratio of 1:12 g / mL between the fibers and the sodium hydroxide solution, and stir and soak at 60°C for 0.5 h; filter, wash with deionized water until the pH of the filtrate is 7, and dry at 105°C for 3 h to obtain activated basalt fibers. γ-aminopropyltriethoxysilane (KH-550) was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to prepare a 2% (w / w) silane coupling agent hydrolysate. The pH was adjusted to 4.5 with acetic acid, and the solution was pre-hydrolyzed at room temperature for 25 min. Activated basalt fibers were added to the silane solution at a mass ratio of 1:0.1 to γ-aminopropyltriethoxysilane. The mixture was stirred at 55 °C for 2.5 h. After filtration, the solution was washed once with anhydrous ethanol and dried at 108 °C for 2.5 h to obtain amino-functionalized basalt fibers.

[0040] (3) By weight, weigh 55 parts of polyether polyol 330N (functionality 3, hydroxyl value 56mgKOH / g), 15 parts of polymer polyol POP (grafted SAN modified, functionality 3, hydroxyl value 28mgKOH / g, solid content about 40%), 40 parts of toluene diisocyanate (TDI-80), 3 parts of water, 10 parts of flame retardant modified filler, 2 parts of amino-functionalized basalt fiber, 1 part of calcium carbonate whiskers (diameter 0.5~2μm, length 5~20μm), 0.5 parts of mica powder (800 mesh white mica powder), 5 parts of bioactive crystal powder (tourmaline powder, Bian stone powder and Maifan stone powder mixed and ground in equal mass ratio, particle size 400 mesh), 0.5 parts of triethanolamine, 0.05 parts of dibutyltin dilaurate, and 0.8 parts of open-cell polyether modified silicone oil. First, amino-functionalized basalt fibers were added to a portion of polyether polyol and pre-dispersed at 600 rpm for 4 minutes to prepare a fiber masterbatch. Calcium carbonate whiskers and mica powder were added to another portion of polyether polyol and pre-dispersed at 2500 rpm for 8 minutes using a high-speed disperser to prepare a filler masterbatch. The fiber masterbatch, filler masterbatch, and other components (except TDI) were then added to a mixing container and mixed at 1000 rpm for 80 seconds at 50°C to form a uniform premix of component A. Then, TDI (component B) was added and rapidly mixed at 2500 rpm for 8 seconds until homogeneous. The mixture was immediately poured into a mattress mold preheated to 52°C. The milky whitening time was approximately 10 seconds, and the gelation time was approximately 100 seconds. The mixture was kept in the mold for another 6 minutes until the foam had sufficient green strength before demolding. The final product was cured at room temperature for 36 hours.

[0041] Comparative Example 1: Compared with Example 4, the in-situ deposition and coating step of aluminum hydroxide was omitted in step (1), and APP-loaded sepiolite was directly used as a flame retardant filler, while the other conditions remained unchanged.

[0042] Comparative Example 2: Compared with Example 4, the grafting modification step of γ-aminopropyltriethoxysilane was omitted in step (2), and the activated basalt fiber after alkali washing was directly used in the foaming formula, while the other conditions remained unchanged.

[0043] Comparative Example 3: Compared with Example 4, the foaming formula in step (3) does not contain calcium carbonate whiskers and mica powder, while the other conditions remain unchanged.

[0044] Comparative Example 4: Compared with Example 4, in step (1), instead of using sepiolite as a carrier for vacuum impregnation loading, equal amounts of ammonium polyphosphate powder, aluminum hydroxide powder and sepiolite powder were mixed with sepiolite powder by simple mechanical blending and then used directly as flame retardant filler, with the other conditions remaining unchanged.

[0045] Comparative Example 5: Compared with Example 4, the alkaline washing and activation treatment step was omitted in step (2), and the untreated raw basalt short-cut fibers were directly used in the foaming formula, while the other conditions remained unchanged.

[0046] Comparative Example 6: Compared with Example 4, the foaming formulation in step (3) does not contain amino-functionalized basalt fiber (i.e., the amount of reinforcing fiber is 0 parts), and the other conditions remain unchanged.

[0047] Comparative Example 7: Compared with Example 4, calcium carbonate whiskers were not added to the foaming formula in step (3) (1.5 parts of mica powder were added normally), and the other conditions remained unchanged.

[0048] Comparative Example 8: Compared with Example 4, mica powder was not added to the foaming formula in step (3) (calcium carbonate whiskers were added normally in 3 parts), and the other conditions remained unchanged.

[0049] Performance testing: 1. Tensile strength and elongation at break test: The test was conducted in accordance with GB / T 6344-2008 "Determination of tensile strength and elongation at break of flexible foam polymer materials". The foam material was cut into dumbbell-shaped specimens (total length not less than 150 mm, width of narrow part (25±1) mm, thickness (10±1) mm). The tensile test was carried out on a universal testing machine at a tensile rate of (500±50) mm / min. The maximum load at break and the change in the spacing between the marks were recorded. The tensile strength and elongation at break were calculated respectively. The median of 5 specimens in each group was taken.

[0050] 2. Tear strength test: The test was conducted in accordance with GB / T 10808-2006 "Determination of tear strength of porous polymer elastic materials". The foamed material was cut into trouser-shaped specimens (length not less than 150 mm, width (25±1) mm, thickness (10±1) mm, with a 50 mm long longitudinal cut in the middle). The two trouser legs were stretched in opposite directions at a tensile rate of (100±10) mm / min on a universal testing machine. The median value of the force during the tearing process was recorded. The tear strength (N / cm) was calculated by dividing the force value by the specimen thickness. The median of 5 specimens in each group was taken.

[0051] 3. Compression set test: The test was conducted in accordance with GB / T 6669-2008 "Determination of compression set of flexible foam polymer materials". A sample with a size of (50±1)mm×(50±1)mm×(25±1)mm was cut from the foam material and compressed to 50% of the original thickness in a compression fixture. After being placed in a hot air circulating oven at (70±2)℃ for 22 hours, the sample was removed and allowed to recover in a standard environment for 30 minutes. The thickness after recovery was measured, and the compression set rate was calculated according to the formula Ct=(d0-d2) / d0×100%. The arithmetic mean of 3 samples in each group was taken.

[0052] 4. Limiting Oxygen Index Test: The test shall be conducted in accordance with GB / T 2406.2-2009 "Determination of Combustion Behavior by Oxygen Index Method for Plastics - Part 2: Room Temperature Test". The foamed material shall be cut into strips of (150±0.5)mm×(10±0.5)mm×(10±0.5)mm and fixed vertically in the sample holder of the oxygen index tester. The oxygen concentration of the oxygen-nitrogen mixture shall be adjusted from a higher oxygen concentration and gradually decreased. The lowest oxygen concentration that can maintain stable combustion of the sample for 3 minutes or the combustion length reaches 50mm shall be recorded as the limiting oxygen index (LOI). Each test shall have no less than 15 samples.

[0053] 5. Vertical Burning Test: The test shall be conducted according to the vertical burning method in GB / T 2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Methods". The foamed material shall be cut into strips of (125±5)mm×(13.0±0.5)mm×(13±0.5)mm and held vertically in the combustion chamber. The lower end of the sample shall be subjected to two 10s flame treatments with a 50W standard test flame (Bunsen lamp with a flame height of 20mm). The duration of flaming combustion (t1 and t2) after the flame is removed each time and the duration of flameless combustion (t3) after the second flame treatment shall be recorded. It shall be observed whether there are burning droplets that ignite the degreased cotton below. The V-0, V-1 or V-2 rating shall be determined according to the standard.

[0054] Table 1:

[0055] Compared to Example 4, Comparative Example 1 showed a significant decrease in LOI from 29.8% to 23.4%, and a decrease in flame retardancy rating from V-0 to V-1, confirming the crucial role of the aluminum hydroxide shell as the first flame-retardant barrier and its synergistic flame-retardant effect with APP. Compared to Example 4, Comparative Example 2 showed a decrease in tear strength from 6.9 N / cm to 4.3 N / cm (a decrease of 37.7%), indicating that the reinforcement efficiency of fibers lacking chemical bonds is significantly reduced when relying solely on physical embedding, highlighting the critical role of covalent interfaces in stress transfer. Compared to Example 4, Comparative Example 3 showed a decrease in tear strength from 6.9 N / cm to 4.1 N / cm (a decrease of 40.6%), even slightly greater than Comparative Example 2, confirming that the absence of cell structure compensation components in high-filler systems leads to cell wall defects that significantly weaken the fiber reinforcement effect.

[0056] Compared to Example 4, Comparative Example 4 showed a decrease in LOI from 29.8% to 24.8%, a decrease in flame retardancy rating to V-1, and a decrease in tensile strength and elongation at break of 20% and 14.5%, respectively, while the compression set increased to 8.8%. This demonstrates that the structured carrier design is significantly superior to traditional physical blending methods in improving flame retardancy efficiency and maintaining mechanical properties. Compared to Example 4, Comparative Example 5 showed a decrease in tear strength from 6.9 N / cm to 4.5 N / cm (a decrease of 34.8%), similar to Comparative Example 2 (fibers without silane grafting, 4.3 N / cm). This is because the surface of the un-alkali-washed fiber is covered by the organic sizing agent, and the silanol active sites are not exposed. The silane coupling agent cannot form effective Si-O-Si covalent bonds with the fiber surface, and can only produce weak physical adsorption on the sizing agent surface. Therefore, its reinforcement efficiency is close to that of the completely un-silane-grafted fiber (Comparative Example 2), which indirectly proves that alkali washing activation is a necessary prerequisite step for silane coupling grafting.

[0057] Compared with Example 4, Comparative Example 6 showed a sharp drop in tear strength from 6.9 N / cm to 2.6 N / cm (a decrease of 62.3%), the largest decrease among all comparative examples, directly proving that the reinforcing fiber is the core contributing factor to the improvement of tear resistance.

[0058] Compared with Comparative Example 3, Comparative Example 7 (with whiskers removed) had a tear strength of 5.4 N / cm, Comparative Example 8 had a tear strength of 5.8 N / cm, while Comparative Example 3 had a tear strength of only 4.1 N / cm. The performance degradation of Comparative Examples 7 and 8 was less than that of Comparative Example 3, indicating that whiskers and mica have a significant synergistic effect. The two work together at different stages of crack initiation and propagation to produce a cellular structure reinforcement effect of 1+1>2.

[0059] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the essence and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a foaming material containing bioactive crystals, characterized in that, Includes the following steps: (1) Provide a flame-retardant filler with a core-shell structure, wherein the flame-retardant filler uses porous minerals as a carrier, and phosphorus-nitrogen flame retardants are loaded on its surface and in its pores, and an inorganic flame-retardant shell is coated on its exterior. The preparation process of the flame-retardant filler with the core-shell structure includes: The porous mineral is activated to obtain an activated mineral carrier; The phosphorus-nitrogen flame retardant is formulated into a slurry or solution, and the activated mineral carrier is impregnated in the slurry or solution under negative pressure or vacuum conditions to achieve the loading of the flame retardant into the interior and surface of the mineral pores. The inorganic flame-retardant shell layer is formed by depositing metal hydroxides on the surface of a mineral carrier loaded with phosphorus and nitrogen flame retardants through in-situ chemical precipitation. The porous mineral is at least one of sepiolite, attapulgite, or wollastonite; the phosphorus-nitrogen flame retardant is at least one of ammonium polyphosphate, melamine polyphosphate, or melamine cyanurate; and the inorganic flame-retardant shell is aluminum hydroxide or magnesium hydroxide. The activation treatment is an acid activation treatment, specifically as follows: natural sepiolite powder is added to a hydrochloric acid solution with a mass concentration of 8-12%, and stirred at 60-70℃ for 1.5-2.5 hours at a solid-liquid ratio of 1:(5-8) g / mL; after filtration, washing with water and drying, activated sepiolite is obtained; the mass ratio of ammonium polyphosphate to the activated mineral carrier is (0.6-1.5):1; (2) Provide reinforcing fibers, wherein the surface of the reinforcing fibers is grafted with active groups capable of reacting with isocyanate groups; (3) Mix the polyol component, isocyanate component, foaming agent, flame retardant filler, reinforcing fiber, calcium carbonate whiskers, mica powder, bioactive crystal powder, catalyst and foam leveling agent, and carry out foaming reaction and curing to obtain the product.

2. The method for preparing a foaming material containing bioactive crystals according to claim 1, characterized in that, The preparation process of the reinforcing fiber in step (2) includes: Inorganic fibers are subjected to alkaline washing and activation treatment to expose the silanol groups on the fiber surface; The inorganic fibers after alkali washing are grafted with a silane coupling agent containing the active groups, so that the active groups are anchored to the fiber surface through siloxane bonds.

3. The method for preparing a foaming material containing bioactive crystals according to claim 2, characterized in that, The inorganic fiber is chopped basalt fiber or glass fiber; the active group is a primary amine group or a secondary amine group; and the silane coupling agent is an aminosilane coupling agent.

4. The method for preparing a foaming material containing bioactive crystals according to claim 3, characterized in that, The specific operation of the alkaline washing and activation process is as follows: The inorganic fibers are added to a sodium hydroxide solution with a mass concentration of 3-5% and stirred and soaked at 60-70°C for 0.5-1.5 hours; after filtration, washing and drying, activated fibers are obtained. The mass ratio of the activated fiber to the aminosilane coupling agent is 1:(0.1-0.3).

5. The method for preparing a foaming material containing bioactive crystals according to claim 1, characterized in that, The polyol component includes polyether polyols and polymer polyols; The isocyanate component is toluene diisocyanate; The foaming agent is water; The catalysts include amine catalysts and organotin catalysts; The foaming agent is an open-cell polyether modified silicone oil; The bioactive crystal powder is made by mixing and grinding tourmaline powder, bian stone powder and maifan stone powder in equal mass ratio; The weight ratio of each component in step (3) is as follows: The composition includes 55-65 parts polyether polyol, 15-25 parts polymer polyol, 40-55 parts toluene diisocyanate, 3-5 parts water, 10-18 parts of the flame retardant filler, 2-6 parts of the reinforcing fiber, 1-3 parts calcium carbonate whiskers, 0.5-1.5 parts mica powder, 5-10 parts bioactive crystal powder, 0.5-1.0 parts amine catalyst, 0.05-0.15 parts organotin catalyst, and 0.8-1.5 parts open-cell polyether modified silicone oil.

6. A foaming material containing bioactive crystals, characterized in that, It is prepared by the method described in any one of claims 1 to 5 above.

7. The application of a foam material containing bioactive crystals as described in claim 6 in a mattress.

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