A long-acting antibacterial sponge for a mattress and a method of using the same

Abstract

The present application relates to the technical field of functional polyurethane foam, and particularly relates to a long-acting antibacterial sponge for a mattress and a preparation method thereof. The long-acting antibacterial sponge comprises the following components in parts by weight: a polyol component 100 parts, an isocyanate component 30-60 parts, a foaming agent 2-10 parts, a catalyst 0.5-3 parts, a foam stabilizer 0.5-3 parts, an antibacterial component 0.5-5 parts, and functional short fibers 3-15 parts. The antibacterial component comprises a slow-release inorganic antibacterial agent and / or a non-slow-release organic antibacterial agent, and the functional short fibers are polymer short fibers loaded with antibacterial and bacteriostatic particles. The present application realizes chemical sterilization through the antibacterial component in the sponge raw material, realizes physical dust removal through the gradient pore structure to drive dust particles to migrate downward and gather when the mattress is pressed, realizes mechanical reinforcement and fiber loading antibacterial through the functional short fibers, and the three functions are synergized to realize long-acting antibacterial, self-cleaning and anti-deformation functions of the mattress.

Description

Technical Field

[0001] This invention relates to the field of functional polyurethane foam materials technology, specifically to a long-lasting antibacterial sponge for mattresses. Background Technology

[0002] Mattresses are an indispensable part of daily life, and foam mattresses are widely favored for their softness and resilience. However, over time, human skin flakes, sweat, dust, and other organic matter continuously seep into the pores of the foam. Under suitable temperature and humidity conditions, these accumulations become a breeding ground for bacteria, fungi, and other microorganisms. Studies have shown that mattresses used for extended periods contain large amounts of harmful microorganisms, such as Aspergillus, which can potentially lead to cross-infection of colds, Aspergillus pneumonia, sinusitis, asthma, and other diseases. Mattresses are therefore often referred to as "invisible health killers."

[0003] Furthermore, during prolonged exposure to irregular pressure from the human body, the repeated compression-rebound cycles of a foam mattress can lead to gradual fatigue and damage to the internal pore structure of the foam. This manifests as decreased support performance, localized collapse, and accumulated deformation, severely impacting the mattress's lifespan and comfort. This problem is particularly pronounced in traditional antibacterial foams, as the addition of antibacterial agents often affects the cross-linking structure and molecular chain movement of the polyurethane matrix, weakening the foam's mechanical properties and resistance to deformation to some extent.

[0004] In existing technologies, the following technical solutions are mainly used to solve the antibacterial problem of foam mattresses: One approach involves adding antibacterial agents. For example, Chinese patent CN102977333A discloses an antibacterial slow-rebound sponge containing nano-silver. This achieves its bactericidal effect by adding nano-silver antibacterial agents to the polyurethane foam formulation. The nano-silver exerts its antibacterial effect through the slow release of silver ions. Another approach, such as Chinese patent CN107573546A, uses a compound of traditional Chinese medicine powder and nano-silver to prepare an antibacterial sponge mattress. While these approaches offer some antibacterial effects, the antibacterial agents primarily rely on a slow-release mechanism. As usage time increases, the antibacterial agents are gradually consumed, leading to a decline in antibacterial performance and making it difficult to achieve truly long-lasting antibacterial effects.

[0005] Secondly, a multi-layered composite structure is used. For example, Chinese patent CN206238915U discloses a sponge health mattress with antibacterial and anti-mite properties, which consists of multiple layers from top to bottom, including an antibacterial and anti-mite sponge layer, a mesh foam plastic layer, and a high-elastic sponge layer. This type of solution achieves multiple layers of protection through functional layering, but the layers are fixedly composited and cannot actively remove dust and particles that have accumulated inside each layer, resulting in insufficient self-cleaning ability at the physical level.

[0006] Thirdly, cleaning can be achieved through a removable and washable outer cover. As shown in the aforementioned patent, a zipper is provided on the side of the outer cover for easy removal and cleaning. However, the outer cover only protects the surface of the mattress; dust and microorganisms accumulated deep within the foam cannot be removed by cleaning the outer cover.

[0007] Overall, existing antibacterial foam mattresses have the following technical defects: (1) In the antibacterial agent slow-release scheme, the antibacterial agent is gradually consumed over time, and the antibacterial performance is weakened, making it difficult to achieve true long-term antibacterial effect; (2) Existing foam mattresses lack a physical mechanism to actively remove accumulated dust and particles inside, and the accumulated matter remains in the foam pores for a long time, continuously providing a breeding environment and nutrients for microorganisms; (3) Chemical antibacterial and physical cleaning lack synergy, failing to form a virtuous cycle of "antibacterial-dust removal-cleaning"; (4) The introduction of antibacterial agents affects the mechanical properties of the foam matrix to a certain extent. Existing solutions fail to simultaneously solve the problem of balancing antibacterial function and deformation resistance, especially lacking a composite technical solution that compensates for mechanical properties and synergistically improves antibacterial effect through fiber reinforcement. Summary of the Invention

[0008] This invention addresses the technical shortcomings of existing antibacterial foam mattresses, such as the decay of antibacterial effect over time, lack of active internal dust removal mechanism, and decline in mechanical properties due to the introduction of antibacterial agents. It provides a long-lasting antibacterial foam for mattresses and its preparation method. The aim is to achieve long-lasting antibacterial properties, self-cleaning of internal particles, and excellent deformation resistance of the foam mattress through the synergistic combination of chemical antibacterial components, physical gradient pore structure, and functional short fiber reinforcement, thereby significantly extending the antibacterial effectiveness and service life of the mattress.

[0009] In a first aspect, the present invention provides a long-lasting antibacterial sponge for mattresses, comprising, by weight, the following components: 100 parts of polyol component, 30-60 parts of isocyanate component, 2-10 parts of foaming agent, 0.5-3 parts of catalyst, 0.5-3 parts of foam stabilizer, 0.5-5 parts of antibacterial component, and 3-15 parts of functional short fibers. The antibacterial component includes a slow-release inorganic antibacterial agent and / or a non-slow-release organic antibacterial agent; the functional short fibers are polymer short fibers loaded with antibacterial and bacteriostatic particles.

[0010] The slow-release inorganic antibacterial agent is selected from one or more of nano-silver, nano-zinc oxide, and nano-copper; the non-slow-release organic antibacterial agent is selected from one or more of quaternary ammonium salt antibacterial agents and polyhexamethylene guanidine antibacterial agents. Preferably, the antibacterial component is a compound of nano-silver and quaternary ammonium salt antibacterial agent, with a mass ratio of nano-silver to quaternary ammonium salt antibacterial agent of 1:(0.5~3). The average particle size of the nano-silver is preferably 10~100nm.

[0011] In the functional short fibers, the polymer is selected from one or more of polyamide fiber (PA), polyester fiber (PET), and polypropylene fiber (PP); the antibacterial and bacteriostatic particles are selected from one or more of nano-silver, nano-zinc oxide, and nano-titanium dioxide. Preferably, the functional short fibers are polyamide short fibers prepared by melt spinning of antibacterial masterbatch, wherein the antibacterial and bacteriostatic particles are nano-silver and / or nano-zinc oxide, and the mass fraction of the antibacterial and bacteriostatic particles in the short fibers is 0.5% to 5%; the length of the functional short fibers is 1 to 10 mm, and the fineness is 1.5 to 6 D.

[0012] The sponge is composed of multiple layers of sponge sheets stacked from top to bottom, with the porosity of each layer increasing progressively from top to bottom. Preferably, the number of layers in the multilayer sponge sheet is 3 to 10; the porosity of the top layer is 10% to 25%, the porosity of the bottom layer is 50% to 80%, and the porosity of the intermediate layers increases gradually; the thickness of a single layer of sponge sheet is 0.5 to 3 cm.

[0013] Preferably, the content of antibacterial components in each layer of sponge sheet increases from top to bottom, with the content of antibacterial components in the bottom layer being 1.5 to 3 times that of the top layer; the content of functional short fibers in each layer of sponge sheet decreases from top to bottom, with the content of short fibers in the bottom layer being 0.3 to 0.7 times that of the top layer.

[0014] Secondly, the present invention provides a method for preparing the above-mentioned long-lasting antibacterial sponge for mattresses, comprising the following steps: Step 1: Preparation of functional short fibers: Antibacterial and bacteriostatic granules are mixed with polymer matrix resin according to a certain ratio and granulated to obtain antibacterial masterbatch; the antibacterial masterbatch is mixed with polymer matrix resin and then melt-spun and cut to obtain functional short fibers. The preferred melting spinning temperature is 220~280℃, the preferred spinning speed is 800~1500m / min, and the preferred draw ratio is 2~5 times.

[0015] Step 2: Prepare the foaming material for the sponge: Mix the polyol components, foaming agent, catalyst, foam stabilizer, antibacterial components and functional short fibers evenly according to the specified ratio to obtain the foaming mixture.

[0016] Step 3: Add the isocyanate component to the foaming mixture, stir at high speed, and then pour it into the foaming mold for foaming and molding. After curing, a sponge block is obtained.

[0017] Step 4: Cut the sponge block obtained in Step 3 into sponge sheets of a predetermined thickness.

[0018] Step 5: Perform porosity gradient treatment on different sponge sheets to achieve a preset porosity for each sponge sheet. The porosity gradient treatment adopts one or a combination of the following methods: (a) compression shaping treatment of the sponge sheets under different pressures, with a pressure range of 0.1~2MPa; (b) independent foaming molding of different sponge sheets using different foaming formulas, controlling the porosity by adjusting the amount of foaming agent; (c) mechanical perforation treatment of the sponge sheets to control the pore density and pore size.

[0019] Step Six: Stack the sponge sheets after porosity gradient treatment in order of increasing porosity from top to bottom, and then fix them through interlayer composite to obtain a long-lasting antibacterial sponge. The preferred interlayer composite fixing method is hot-pressing, with a hot-pressing temperature of 120~180℃, a pressure of 0.2~1MPa, and a holding time of 30~120 seconds.

[0020] Compared with the prior art, the present invention has the following significant advantages: (I) A dual synergistic antibacterial mechanism combining chemical antibacterial agents and physical dust removal. This invention, on the one hand, adds antibacterial components (such as nano-silver and quaternary ammonium salts) to the sponge material, endowing it with active bactericidal capabilities; on the other hand, it creates a gradient structure with increasing porosity from top to bottom through multi-layered thin sheets. When the sponge is subjected to irregular pressure from the human body, each layer undergoes different deformations. A pressure difference is created between the lower layer with higher porosity (smaller deformation) and the upper layer with lower porosity (larger deformation), driving dust and particles accumulated in the upper layer's pores to migrate and accumulate in the larger pores of the lower layer. Regular cleaning of the mattress (such as beating or vacuuming) can remove the particles accumulated in the lower layer. Chemical antibacterial agents inhibit microbial growth, while physical dust removal removes the organic nutrients needed for microbial growth. The two work synergistically to form a virtuous cycle of "antibacterial-dust removal-cleaning," significantly improving the long-term hygiene performance of the mattress.

[0021] (II) Multiple Reinforcing Effects of Functional Short Fibers. This invention introduces functional short fibers loaded with antibacterial and bacteriostatic particles into the sponge matrix, resulting in the following multiple beneficial effects: First, the short fibers are uniformly dispersed in the sponge pore walls, significantly enhancing the tear strength and fatigue resistance of the sponge matrix through fiber bridging and anchoring. This effectively compensates for the mechanical weakening of the polyurethane cross-linked structure caused by the introduction of antibacterial agents, allowing the sponge to maintain good structural integrity and deformation resistance during long-term repeated compression, making the mattress less prone to collapse. Second, the antibacterial and bacteriostatic particles loaded on the short fibers themselves provide additional antibacterial active sites, forming a three-dimensional antibacterial network with the antibacterial components in the matrix, further improving the overall antibacterial efficiency of the sponge. Even if the matrix antibacterial agent decays, the antibacterial particles loaded on the fibers can still maintain a certain level of antibacterial activity. Third, the addition of short fibers improves the surface roughness and polarity of the sponge pore walls, which is beneficial for dust particles to adhere to the fiber surface rather than being deeply embedded in the pore walls during pressure migration, improving the efficiency of physical dust removal and cleanability.

[0022] (III) Truly Long-Lasting Antibacterial Effect. Existing technologies that rely solely on the slow release of antibacterial agents experience a decline in antibacterial performance as the agents are gradually depleted. In this invention, the physical dust removal mechanism does not rely on the consumption of chemical substances and can continuously remove dust, reducing the breeding ground for microorganisms at its source. Simultaneously, the antibacterial particles loaded in the functional short fibers are evenly distributed within and on the surface of the fiber matrix. As the antibacterial particles on the fiber surface are gradually exposed and released, a continuous antibacterial replenishment mechanism is formed, creating a "tiered release" effect with the matrix antibacterial agent. Even if the matrix antibacterial components decay over time, the physical dust removal mechanism and the fiber-loaded antibacterial particles can still maintain a low-bacterial environment inside the mattress, thus achieving a lifespan far exceeding that of single-antibacterial agent solutions.

[0023] (iv) Spatial Adaptation of Gradient Pore Structure and Functional Short Fibers. This invention further optimizes the short fiber content in each layer of the sponge sheet by decreasing from top to bottom. This is because the lower layer's large pore structure has relatively lower requirements for mechanical reinforcement, and reducing the short fiber content in the lower layer helps reduce the physical obstruction of particles' downward migration, allowing dust particles to more smoothly accumulate in the large pores. Conversely, the upper layer's small pore structure has the highest requirements for mechanical properties and deformation resistance; a higher short fiber content effectively enhances the durability of the upper structure. This spatial adaptation design achieves optimal matching between the material properties and functional requirements of each layer. Simultaneously, the antibacterial component content increases from top to bottom in each layer, strengthening the antibacterial ability of the bottom layer's large pores and preventing bacteria growth from particles accumulating at the bottom layer, forming a gradient functional layout of "upper layer antibacterial - middle layer dust guiding - lower layer bacteria collection and inactivation."

[0024] (v) Gradient pore structure adapted to human body pressure distribution characteristics. When a person lies down, the pressure exerted on the mattress by different parts of the body is unevenly distributed. In this invention, the gradient pore structure makes the deformation response of each layer of the sponge different when it is compressed, which not only ensures the comfort and support performance of the mattress, but also realizes the directional migration of particles, and achieves excellent self-cleaning function without sacrificing the comfort of use. Detailed Implementation

[0025] The present invention will be described below with reference to examples. These examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Example 1

[0026] A method for preparing long-lasting antibacterial foam for mattresses Preparation of functional short fibers: Nano-silver particles (average particle size 30nm) and polyamide 6 (PA6) matrix resin were mixed at a mass ratio of 2:98, and then melt-blended and granulated using a twin-screw extruder to obtain an antibacterial masterbatch. The antibacterial masterbatch was then mixed with PA6 resin at a mass ratio of 1:1 and fed into a melt spinning machine at a spinning temperature of 240℃, a spinning speed of 1000m / min, and a draw ratio of 3 times to obtain functional PA6 filaments containing nano-silver. These filaments were then cut into functional short fibers with a length of 3mm and a fineness of 3D using a cutting machine.

[0027] Preparation of sponge sheets: Based on 100 parts by mass of polyol component, weigh out 45 parts of toluene diisocyanate (TDI, 2,4- and 2,6- isomer ratio of 80:20), 4 parts of water (foaming agent), 0.8 parts of triethylenediamine (amine catalyst), 0.5 parts of stannous octoate (tin catalyst), 1.5 parts of polysiloxane-olefin oxide copolymer (foam stabilizer), 2 parts of nano-silver antibacterial agent (particle size 40nm), and 8 parts of the above-mentioned functional short fibers. Premix the polyol component with all components except isocyanate until homogeneous. After adding the isocyanate component, stir at high speed for 45-60 seconds. Pour into molds of different sizes for foaming. After curing at room temperature for 24 hours, demold to obtain sponge blocks of different densities.

[0028] The obtained sponge block was cut into thin sheets with a thickness of 1.5 cm. Through mechanical compression and shaping treatment under different pressures, four layers of sponge sheets with porosities of 15% (upper layer), 30% (upper middle layer), 45% (lower middle layer), and 65% (lower layer) were obtained respectively.

[0029] The content of antibacterial components in each layer of sponge sheet increases from top to bottom, at 1.5 parts, 2 parts, 2.5 parts, and 3 parts respectively (based on 100 parts of polyol); the content of functional short fibers decreases from top to bottom, at 12 parts, 9 parts, 6 parts, and 3 parts respectively (based on 100 parts of polyol).

[0030] Interlayer lamination: The above four layers of sponge sheets are stacked from top to bottom in the order of porosity of 15%, 30%, 45%, and 65%, and placed in a hot press. They are hot-pressed for 60 seconds at a temperature of 150°C and a pressure of 0.5MPa. After cooling, a long-lasting antibacterial sponge product is obtained.

[0031] Antibacterial performance test: Referring to GB / T 20944.3-2008 standard, using Escherichia coli and Staphylococcus aureus as test bacteria, the antibacterial rate of the sponge sample from Example 1 of this invention and a common antibacterial sponge (with equal amounts of nano-silver added, uniform porous structure, and no functional short fibers) was compared. The results showed that the initial antibacterial rate was 99.9% for this invention and 99.5% for the common antibacterial sponge. After simulated use (5000 cycles of repeated loading and unloading), the antibacterial rate of the sponge from this invention remained above 96.5%, while that of the common antibacterial sponge decreased to 72%.

[0032] Dust removal performance test: A quantitative standard dust (simulating human skin flakes and dust) was evenly distributed on the surface of the sponge sample. After 500 cycles of simulated human body pressure loading-unloading (frequency 0.5Hz, pressure 5kPa), the amount of residual dust inside the sponge was measured. The residual dust amount of the sponge (gradient pores + short fibers) of this invention is only 25% of that of ordinary uniform pore sponge (without short fibers), indicating that the gradient pore structure significantly promotes the downward migration and aggregation of particles, and the presence of short fibers increases the surface roughness of the pore walls, which is conducive to particle adhesion rather than embedding, further improving cleanability.

[0033] Deformation resistance test: Referring to GB / T 6669-2008 standard, the compression set of the sponge sample was measured after aging at 75% compression and 70℃ for 22 hours. The compression set of the sponge of this invention was 4.2%, while that of ordinary antibacterial sponge (without short fibers) was 8.7%, indicating that the addition of functional short fibers significantly improved the sponge's deformation resistance and structural stability.

[0034] Tear strength test: According to GB / T 10808-2006 standard, the tear strength of the sponge of this invention is 4.8 N / cm, while that of ordinary antibacterial sponge (excluding short fibers) is 2.9 N / cm, representing an improvement of 65.5%.

[0035] Air permeability test: According to GB / T 5453-1997 standard, the air permeability of the sponge of this invention is 1750~2150mm / s, which is better than the 1200~1500mm / s of ordinary uniform pore sponge. Example 2

[0036] A method for preparing long-lasting antibacterial foam for mattresses Preparation of functional short fibers: Nano zinc oxide particles (average particle size 50nm) and polyethylene terephthalate (PET) resin were mixed at a mass ratio of 3:97 and granulated to obtain antibacterial masterbatch. The antibacterial masterbatch and PET resin were mixed at a mass ratio of 1:2 and then melt-spun at a spinning temperature of 265℃, a spinning speed of 1200m / min, a draw ratio of 4, and cut into functional short fibers with a length of 5mm and a fineness of 4D.

[0037] Preparation of the sponge sheet: Based on 100 parts by weight of polyol component, weigh out 38 parts of toluene diisocyanate, 3 parts of water, 2 parts of n-pentane (composite foaming agent), 1 part of triethanolamine (amine catalyst), 0.6 parts of dibutyltin dilaurate (tin catalyst), and 1.8 parts of foam stabilizer. The antibacterial component is a compound of nano-silver and quaternary ammonium salt (hexadecyltrimethylammonium chloride) in a 1:1 mass ratio, added at 3 parts by weight. The amount of functional short fiber added is 10 parts by weight.

[0038] Using the same foaming process as in Example 1, five sponge sheets with different porosities (porosities of 12%, 22%, 35%, 50%, and 68% respectively) were prepared. The thickness of each layer was 2 cm. The content of antibacterial components in each layer increased from top to bottom (the bottom layer was twice that of the top layer), and the content of short fibers decreased from top to bottom (the bottom layer was 0.5 times that of the top layer). The layers were fixed together with polyurethane adhesive.

[0039] Performance test results: After simulated use, the antibacterial rate was maintained at 96.8%, the dust residue was 28% of that of ordinary sponge, the compression set was 3.8%, and the tear strength was 5.1 N / cm. Example 3

[0040] A method for preparing long-lasting antibacterial foam for mattresses Preparation of functional short fibers: Nano-silver particles (average particle size 25nm) and polypropylene (PP) resin were mixed at a mass ratio of 1.5:98.5 and granulated to obtain antibacterial masterbatch. The antibacterial masterbatch was mixed with PP resin at a mass ratio of 3:7 and then melt-spun at a spinning temperature of 230℃, a spinning speed of 900m / min, a draw ratio of 3.5 times, and cut into functional short fibers with a length of 2mm and a fineness of 2.5D.

[0041] Preparation of sponge sheet: Based on 100 parts by mass of polymethylene polyphenyl isocyanate (polymeric MDI), weigh 50 parts of water, 1.2 parts of triethylenediamine, 0.8 parts of stannous octoate, 2 parts of foam stabilizer, 5 parts of nano zinc oxide antibacterial agent, 1 part of polyhexamethylene guanidine antibacterial agent, and 5 parts of functional short fiber.

[0042] In this embodiment, the porosity of each layer is controlled by using different foaming formulations for independent foaming. By adjusting the amount of foaming agent (water) to 3 parts, 4 parts, 5 parts, 6 parts and 7 parts respectively, five-layer sponge sheets with porosities of 18%, 30%, 42%, 55% and 70% are obtained, with a single layer thickness of 1cm. The sheets are then fixed by hot pressing (temperature 160℃, pressure 0.6MPa, pressure holding time 45 seconds).

[0043] Performance test results: antibacterial retention rate was 95.2%, dust residue was 30% of that of ordinary sponge, compression set was 4.5%, and tear strength was 4.2 N / cm.

[0044] Comparative Example 1: The same raw material formula and total thickness (6cm) as Example 1 were used, but a uniform pore structure (one-piece foamed sponge with a porosity of 35% in each layer) was used, without functional short fibers, and the other conditions were the same as in Example 1.

[0045] Comparative Example 2: The same gradient pore structure as in Example 1 was used, but no functional short fibers were added, and the other conditions were the same as in Example 1.

[0046] Comparative Example 3: The same raw material formulation as Example 1 was used, with the same amount of ordinary PA6 short fibers (without antibacterial particles) added, and a uniform pore structure was adopted. All other conditions were the same as in Example 1.

[0047] Table 1 shows the test results of sponges in Example 1 and Comparative Examples 1-3. It can be seen that Comparative Example 1 (uniform pores + no short fibers) has a significantly reduced antibacterial rate after simulated use due to the lack of a physical dust removal mechanism of gradient pores, the highest amount of residual dust, and the worst deformation resistance. Although Comparative Example 2 (gradient pores + no short fibers) has better dust removal performance than Comparative Example 1, it still has poor deformation resistance due to the lack of short fiber reinforcement. At the same time, due to the lack of supplementary antibacterial effect of fiber-loaded antibacterial particles, the antibacterial rate after simulated use is lower than that of Example 1. Although the tear strength of Comparative Example 3 (ordinary short fibers + uniform pores) is improved, ordinary short fibers do not have antibacterial function, and uniform pores lack dust removal ability. Therefore, it has the lowest antibacterial rate and extremely high amount of residual dust after simulated use.

[0048] Table 1. Sponge detection results for Example 1 and Comparative Examples 1-3 Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial antibacterial rate 99.9% 99.5% 99.6% 98.2% Antibacterial rate after simulated use 96.5% 71.8% 89.3% 68.5% Residual dust amount (relative value) 25% 100% 32% 95% Compression permanent deformation rate 4.2% 8.7% 7.9% 5.8% Tear strength (N / cm) 4.8 2.9 3.1 4.3 In Embodiment 1 of the present invention, the optimal results were achieved in terms of antibacterial durability, dust removal efficiency and deformation resistance through the triple synergy of chemical antibacterial components, fiber-loaded antibacterial properties of functional short fibers and physical dust removal through gradient pores.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A long-lasting antibacterial sponge for mattresses, characterized in that, Based on parts by weight, it includes the following components: The composition includes 100 parts of polyol, 30-60 parts of isocyanate, 2-10 parts of foaming agent, 0.5-3 parts of catalyst, 0.5-3 parts of foam stabilizer, 0.5-5 parts of antibacterial component, and 3-15 parts of functional short fiber. The antibacterial components include sustained-release inorganic antibacterial agents and / or non-sustaining-release organic antibacterial agents; The functional short fiber is a polymer short fiber loaded with antibacterial and bacteriostatic particles.

2. The long-lasting antibacterial sponge for mattresses according to claim 1, characterized in that, The multilayer sponge sheet has 3 to 10 layers; the porosity of the top layer is 10% to 25%, the porosity of the bottom layer is 50% to 80%, and the porosity of each intermediate layer increases in a gradient; the thickness of a single layer of sponge sheet is 0.5 to 3 cm.

3. The long-lasting antibacterial sponge for mattresses according to claim 1, characterized in that, The sustained-release inorganic antibacterial agent is selected from one or more of nano-silver, nano-zinc oxide, and nano-copper; the non-sustaining-release organic antibacterial agent is selected from one or more of quaternary ammonium salt antibacterial agents and polyhexamethylene guanidine antibacterial agents.

4. The long-lasting antibacterial sponge for mattresses according to claim 3, characterized in that, The antibacterial component is composed of nano-silver and quaternary ammonium salt antibacterial agent, with a mass ratio of nano-silver to quaternary ammonium salt antibacterial agent of 1:(0.5~3).

5. The long-lasting antibacterial sponge for mattresses according to claim 1, characterized in that, In the functional short fibers, the polymer is selected from one or more of polyamide fibers, polyester fibers, and polypropylene fibers; the antibacterial and bacteriostatic particles are selected from one or more of nano silver, nano zinc oxide, and nano titanium dioxide.

6. The long-lasting antibacterial sponge for mattresses according to claim 5, characterized in that, The functional short fiber is a polyamide short fiber prepared by melt spinning of antibacterial masterbatch, wherein the antibacterial and bacteriostatic particles are nano-silver and / or nano-zinc oxide, and the mass fraction of the antibacterial and bacteriostatic particles in the short fiber is 0.5%~5%; the length of the functional short fiber is 1~10mm and the fineness is 1.5~6D.

7. A method for preparing a long-lasting antibacterial sponge for mattresses as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Preparation of functional short fibers: Antibacterial and bacteriostatic particles are mixed with polymer matrix resin in a certain proportion and granulated to obtain antibacterial masterbatch; after mixing the antibacterial masterbatch with polymer matrix resin, the mixture is melt-spun and cut to obtain functional short fibers; Step 2: Prepare the foaming material for the sponge: Mix the polyol components, foaming agent, catalyst, foam stabilizer, antibacterial components and functional short fibers evenly according to the specified ratio to obtain the foaming mixture; Step 3: Add the isocyanate component to the foaming mixture, stir at high speed, and then pour it into the foaming mold for foaming and molding. After curing, a sponge block is obtained. Step 4: Cut the sponge block obtained in Step 3 into sponge sheets of a predetermined thickness; Step 5: Perform porosity gradient treatment on different sponge sheets to make each sponge sheet reach the preset porosity. Step 6: Stack the sponge sheets after the porosity gradient treatment in order of increasing porosity from top to bottom, and after interlayer composite fixation, obtain the long-lasting antibacterial sponge.

8. The preparation method according to claim 7, characterized in that, The porosity gradient treatment in step five employs one or a combination of the following methods: (a) Compression shaping treatment of sponge sheets under different pressures, with a pressure range of 0.1~2MPa; (b) Different foaming formulations were used to independently foam different sponge sheets, and the porosity was controlled by adjusting the amount of foaming agent. (c) Mechanically perforate the sponge sheet to control the pore density and pore size.

9. The preparation method according to claim 7, characterized in that, The interlayer composite fixation in step six is ​​hot-pressed composite, with a hot-pressing temperature of 120~180℃, a pressure of 0.2~1MPa, and a holding time of 30~120 seconds.

10. The preparation method according to claim 7, characterized in that, The spinning temperature of the melt spinning in step one is 220~280℃, the spinning speed is 800~1500m / min, and the draw ratio is 2~5 times.