Washable high-breathability slow-rebound silica gel sponge

Abstract

The invention relates to the field of refractory materials, and discloses a washable high-breathability slow-resilience silica gel sponge which comprises the following components in parts by weight: 10-20 parts of block modified nanoparticles, 50-60 parts of a silica gel matrix, 10-20 parts of an elastic block body and 3-5 parts of a compatilizer, the washable high-breathability slow-resilience silica gel sponge is of a pore channel structure with the average pore diameter being 200-400 microns, and the density is 0.5-1 g / cm < 3 >. According to the scheme, the elastic block body is used for improving the performance of the silica gel sponge, meanwhile, the block body modified nano particles are used for promoting compatibility, the performance is improved, and mechanical-ventilation balance is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of sponge materials, in particular to a washable, highly breathable, slow-rebound silicone sponge. Background Art

[0002] Traditional silicone sponge materials are prone to elastic attenuation and structural collapse after washing, resulting in a significant decrease in rebound performance and a compression deformation rate generally higher than 15%, which seriously limits its reusability. At the same time, due to the single pore structure and high closed-pore rate of existing materials, the air permeability is mostly lower than 300 cm³ / (cm²·s), which makes it difficult to meet the needs of mattresses, medical protective equipment and other fields for moisture and heat exchange. In addition, although conventional slow-rebound materials can prolong the deformation recovery time, the rebound rate is still too fast to achieve uniform pressure distribution, affecting comfort. The above defects together lead to poor product durability and single function. There is an urgent need to develop a new generation of silicone sponge materials that are both washable, highly breathable and have controllable slow rebound properties. In the prior art, CN115403826A relates to a silicone sponge and its preparation method. The silicone sponge comprises, by weight, 15-40% coarse-pored reticulated polyurethane sponge and 60-85% two-component addition-type silicone. The coarse-pored reticulated polyurethane sponge comprises, by weight, 100 parts of polyether polyol, 35-42 parts of isocyanate, 0.3-0.5 parts of foam stabilizer, 8.5-9.5 parts of blowing agent, 0.3-0.5 parts of reaction catalyst, and 1-2 parts of bactericidal, mite-removing, and mildew-proof agent. The two-component addition-type silicone comprises two components, A and B, in a 1:1 mass ratio. However, this method focuses more on bactericidal effects and less on mechanical properties. Summary of the Invention

[0003] In order to make up for the above shortcomings, the present invention provides a washable, highly breathable, slow-rebound silicone sponge, which uses elastic block bodies to improve the performance of the silicone sponge. At the same time, block-modified nanoparticles are used to promote compatibility, improve performance, and achieve a mechanical-breathability balance.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 10-20 parts of block modified nanoparticles, 50-60 parts of silica gel matrix, 10-20 parts of elastic block and 3-5 parts of compatibilizer; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 200-400 μm and a density of 0.5-1 g / cm 3 ; The preparation method of the block-modified nanoparticles comprises the following steps: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:3-8, adjusting the pH to 8-10, and ultrasonically treating to obtain a precursor, which is calcined at 400-600°C for 2-4h to obtain a TiO2@SiO2 core-shell structure; Step (2): the template agent and ethanol are mixed in a mass ratio of 1:50-100, sodium silicate solution is added until the molar ratio of the template agent to sodium silicate is 1:5-10, and then microwave treatment is performed to form a porous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica.

[0005] Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:1-3 in 50-100 times the mass of a carbonate precursor solution, adjusting the pH to 8.5-9.5, reacting for 1-2 hours, adjusting the pH to 7-8, adding a silane coupling agent in an amount of 0.5-1% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; Step (4): dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2-2.5:1, adding a catalyst, and reacting at 70-80°C for 2-3 hours to obtain a prepolymer, followed by adding a modified nanoparticle dispersion, reacting for 2-3 hours, filtering, washing, and drying to obtain block-modified nanoparticles.

[0006] This approach leverages the complementary ductility of the polyurethane soft segment and the rigidity of silicone to enhance matrix strength. Block-modified nanoparticles enhance matrix strength and promote slow rebound properties. A gradient pore design achieves high air permeability in the silicone sponge. This approach utilizes a TiO2@SiO2 core-shell structure to provide rigid support points. The outer SiO2 layer forms a stable core-shell structure through alkaline hydrolysis and calcination, enhancing the material's compressive resistance. A template is then used to guide the formation of porous nano-SiO2. Its high surface area and open-pore structure provide channels for subsequent gas diffusion. A carbonate precursor solution simultaneously induces surface mineralization of the nanoparticles and lays the foundation for micropore formation. Block-modified nanoparticles, grafted with a silane coupling agent, exhibit good compatibility with both the silicone matrix and the block, improving the nanoparticle's dispersion in the matrix. The auxiliary compatibilizer also acts as a bridge, promoting compatibility between the silicone matrix and the block.

[0007] The technical advantages of this solution are reflected in three aspects: first, water-washing durability. The hydrophobicity of the silica gel matrix and the chemical bonds at the nanoparticle interface (such as Si-O-Si) ensure that the material's pore structure retention rate is ≥95% after 50 water washes, far exceeding that of traditional sponges. Second, anti-collapse. The covalent bonding of core-shell nanoparticles and polyurethane inhibits phase separation, and compression resilience is improved by 40%. Third, breathability and rebound are synergistically controlled. The gas diffusion rate of the gradient pores is 2-3 times higher than that of the homogeneous structure, while the dynamic hydrogen bonds between the polyurethane blocks and the nanoparticles delay stress relaxation, extending the rebound time to 3-5 seconds. This design combines nanocomposite reinforcement, multi-scale pore engineering, and interface synergy to provide a high-performance solution for scenarios such as medical protective equipment.

[0008] Preferably, the silicone matrix is a condensed two-component liquid silicone, the elastic block body is a polyurethane block copolymer, and the compatibilizer is a mixture of an epoxy silane coupling agent and polyethylene glycol in a ratio of 1:0.5-1.

[0009] Preferably, in step (2), the template is hexadecyltrimethylammonium bromide.

[0010] Preferably, in step (3), the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution with a solute molar ratio of 1:1-1.2, and the silane coupling agent is KH560.

[0011] Preferably, the pore structure includes a dense microporous layer with an average pore size of 50-100 μm, a main supporting pore layer with an average pore size of 200-400 μm, and a through-type air-conducting pore with an average pore size of 500-800 μm.

[0012] The pores are mainly divided into these three categories, but the proportions among them have not been determined.

[0013] Preferably, the catalyst in step (4) is dibutyltin dilaurate.

[0014] Preferably, the cleaning process in step (4) is rinsing with butanone or acetone, then rinsing with alcohol, and finally rinsing with deionized water.

[0015] This solution also proposes a method for preparing the washable, highly breathable, slow-rebound silicone sponge as described above, comprising the following steps: Step (a) preparing block-modified nanoparticles; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 1%-3% of the total mass of water-soluble carbonate and 0.01%-0.1% of a surfactant, heating to 60-80° C., continuing to mix, adding 3%-5% of the total mass of an acid initiator, continuing to mix, pre-crosslinking at 60-80° C. for 30-60 minutes, then adding 0.5-1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge.

[0016] In this specific preparation process, the compatibilizer in step (b) is a compound of epoxysilane and polyethylene glycol. During the mixing stage at 60-80°C, the epoxy groups of KH560 form ring-opening bonds (Si-OC bonds) with the Si-OH groups of the silica gel matrix. Simultaneously, the polyethylene glycol hydrogen bonds with the soft segments of the polyurethane elastomer block, forming a dual mechanism of "chemical anchoring and physical expansion" to inhibit phase separation. During the pre-crosslinking stage, the silica gel matrix initially solidifies through a condensation reaction, forming a rigid skeleton to limit excessive bubble expansion. A water-soluble carbonate releases CO2 in the presence of an acidic initiator, and a surfactant stabilizes the bubble nuclei by reducing the gas-liquid interfacial tension. Subsequently, the addition of 0.5-1% deionized water triggers deep crosslinking of the silica gel, which synergizes with the dynamic hydrogen bond network of the elastomer block to form pores. Staged pressure control (2-3MPa → 0.5-1MPa → pressure relief) regulates bubble growth through a pressure gradient: under high pressure, a dense microporous layer blocks water penetration, while pressure relief expands the main support pores to balance mechanical strength and air permeability. Rapid pressure relief generates through-hole air pores to accelerate gas exchange. Block-modified nanoparticles are grafted onto KH560 through surface mineralization (CaCO3 deposition), strengthening the Si-O-Si covalent bond with the silica gel. Simultaneously, the urethane bonds of the polyurethane prepolymer bridge the nanoparticles and the elastic block, achieving a mutually reinforcing effect among all major components. This extends the compression-rebound time to 3-5 seconds, and maintains a pore structure retention rate of ≥95% after 50 washes.

[0017] Preferably, the acid used is citric acid or tartaric acid, and the process of the staged pressure-controlled foaming is as follows: Stage 1: Maintain at 2-3 MPa for 30-50 min; The second stage: reduce the pressure to 0.5-1 MPa and maintain for 20-30 minutes; The third stage: rapid pressure relief to normal pressure.

[0018] Preferably, the cleaning process is repeated 2-3 times, the water absorption-drying process.

[0019] The cleaning process mainly removes residual substances such as water-soluble carbonate reactants.

[0020] The present invention has the following beneficial effects: 1. In terms of components, the basic principle of this solution is to use elastic block copolymers to improve the performance of silicone sponge. To promote compatibility and further enhance performance, this solution uses a synergistic system of block copolymer-modified nanoparticles and gradient pores to achieve a mechanical-breathability balance. In addition to enhancing strength and resilience, the block copolymer-modified nanoparticles can be well dispersed in the matrix and elastic block copolymer, and assist the epoxysilane / polyethylene glycol compound compatibilizer to inhibit the separation of silicone and polyurethane phases. The compression set is ≤5%, and the pore size retention rate after 50 water washes is ≥95%. 2. In the foaming stage, this solution adopts a staged pressure-controlled foaming process in conjunction with an acidic initiator to precisely control bubble growth. A trace amount of water is introduced in the pre-cross-linking stage to trigger the condensation of silicone and the simultaneous curing of the polyurethane dynamic hydrogen bond network. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] Example 1 A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 286 μm and a density of 0.75 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0023] Example 2 A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 20 parts of block-modified nanoparticles, 60 parts of condensation-type two-component liquid silicone, 20 parts of polyurethane block copolymer, and 5 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 290 μm and a density of 0.73 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:6, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 520°C for 2.5h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:9, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:3 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 8.5, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 1% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 3% of the total mass of sodium carbonate and 0.8% of sodium stearate, heating to 80° C., continuing to mix, adding 5% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 0.8% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 50 min under 3 MPa; The second stage: reduce the pressure to 1 MPa and maintain for 30 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0024] Example 3 A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 10 parts of block-modified nanoparticles, 50 parts of condensation-type two-component liquid silicone rubber, 10 parts of polyurethane block copolymer, and 3 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 321 μm and a density of 0.68 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:4, adjusting the pH to 8 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 480°C for 4h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:70, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:7, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:1 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 8.5, reacting for 1.5 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.7% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1.2; and the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2.1:1, adding dibutyltin dilaurate, and reacting at 80°C for 2.5 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 2.5 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 3% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 3% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 50 minutes, then adding 0.6% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 50 min under 2 MPa; The second stage: reduce the pressure to 0.6 MPa and maintain it for 30 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0025] Example 4 By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 316 μm and a density of 0.68 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 3% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 0.6 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0026] Comparative Example 1 The difference from Example 1 is that no block-modified nanoparticles are added: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 55 parts of condensation-type two-component liquid silicone rubber, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 206 μm and a density of 1.10 g / cm 3 ; The silica gel matrix, elastic block body and compatibilizer were mixed in proportion, and then 2% of the total weight of sodium carbonate and 0.05% of sodium stearate were added. The mixture was heated to 80°C and continued to be mixed. Then, 4% of the total weight of citric acid was added and continued to be mixed. After pre-crosslinking at 80°C for 60 minutes, 1% of deionized water was added. After being mixed evenly, the mixture was injected into a mold, foamed and cured under controlled pressure in stages, washed and dried to obtain a washable, highly breathable and slow-rebound silica gel sponge. The process of controlled pressure foaming in stages is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0027] Comparative Example 2 The difference from Example 1 is that no elastic block is added: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone rubber, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 349 μm and a density of 0.53 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, block-modified nanoparticles, and compatibilizer in a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of the staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0028] Comparative Example 3 The difference from Example 1 is that no compatibilizer is added: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone and 15 parts of polyurethane block copolymer; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 428 μm and a density of 0.36 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, the elastic block body and the block modified nanoparticles according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of the staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0029] Comparative Example 4 The difference from Example 1 is that the amount of elastic block added is too large: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 30 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 426 μm and a density of 0.58 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0030] Comparative Example 5 The difference from Example 1 is that only porous nano-silica was prepared: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 302 μm and a density of 0.71 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1) mixing hexadecyltrimethylammonium bromide and ethanol in a mass ratio of 1:80, adding a sodium silicate solution until the molar ratio of hexadecyltrimethylammonium bromide to sodium silicate is 1:8, then treating with a 500W microwave for 20 minutes to form a mesoporous silica precursor, and washing with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (2), dispersing the porous nano-silica mixture by mass in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution with a solute molar ratio of 1:1; and the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0031] Comparative Example 6 The difference from Example 1 is that the nanoparticles are not modified: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 156 μm and a density of 1.23 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, and centrifuging and drying to obtain nanoparticles; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0032] Comparative Example 7 The difference from Example 1 is that no carbonate precursor solution is added: A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 286 μm and a density of 0.95 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in deionized water, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate and 0.05% of sodium stearate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then adding 1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0033] Comparative Example 8 The difference from Example 1 is that no water and surfactant are added in step (b): A washable, highly breathable, slow-rebound silicone sponge comprising: By weight, 15 parts of block-modified nanoparticles, 55 parts of condensation-type two-component liquid silicone, 15 parts of polyurethane block copolymer, and 4 parts of a 1:1 mixture of epoxy silane coupling agent and polyethylene glycol; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 286 μm and a density of 0.95 g / cm 3 ; Preparation method of washable, highly breathable, slow-rebound silicone sponge. Step (a) Preparation of block-modified nanoparticles: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:5, adjusting the pH to 9 with ammonia water, and obtaining a precursor after ultrasonic treatment, calcining at 500°C for 3h to obtain a TiO2@SiO2 core-shell structure; Step (2), cetyltrimethylammonium bromide and ethanol are mixed in a mass ratio of 1:80, sodium silicate solution is added until the molar ratio of cetyltrimethylammonium bromide to sodium silicate is 1:8, and then microwave treatment is performed at 500W for 20min to form a mesoporous silica precursor, which is then washed with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:2 in 80 times the mass of a carbonate precursor solution, adjusting the pH to 9, reacting for 2 hours, adjusting the pH to 7.5, adding a silane coupling agent in an amount of 0.8% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution in a solute molar ratio of 1:1; the silane coupling agent is KH560; Step (4), dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2:1, adding dibutyltin dilaurate, and reacting at 80°C for 3 hours to obtain a prepolymer, then adding a modified nanoparticle dispersion, reacting for 3 hours, filtering, washing, and drying to obtain block-modified nanoparticles; the washing process is washing with butanone, then washing with alcohol, and finally washing with deionized water; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 2% of the total mass of sodium carbonate, heating to 80° C., continuing to mix, adding 4% of the total mass of citric acid, continuing to mix, pre-crosslinking at 80° C. for 60 minutes, then mixing evenly and injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge; the process of the staged controlled pressure foaming is as follows: Stage 1: maintain 40 min under 2.5 MPa; The second stage: reduce the pressure to 1 MPa and maintain it for 20 minutes; The third stage: rapid pressure relief to normal pressure; The cleaning process is repeated 3 times, the water absorption and pressing process.

[0034] Performance testing: 1. Mechanical testing: Refer to the test method of ASTM D3574 to test strength and resilience; 2. Gas permeability test: Use the pressure difference method to measure gas flow rate and test gas permeability; 3. Water washing performance test: After washing 30 times, the pore size retention rate after washing is tested = (1-δρ / ρ0) × (water absorption rate 50次水洗 / Water absorption rate 0)×100%.

[0035] Table 1

[0036] Examples 1-4 have better performance than Comparative Examples 1-8.

[0037] The main difference between Comparative Example 1 and Example 1 is that no block-modified nanoparticles are added. Comparative Example 1 has a high density, fewer pores, low air permeability, and a significantly reduced pore size retention rate after washing. The compressive strength is lower than that of Example 1. This is mainly due to the lack of the reinforcing effect of the nanoparticles, resulting in a loose matrix structure and uneven pores.

[0038] Comparative Example 2 differs from Example 1 primarily in that it lacks the addition of an elastomeric block, resulting in a greater probability of phase separation and the potential formation of numerous microcracks. This results in higher permeability-related parameters, lower elasticity, and, conversely, lower compressive strength. Similarly, Comparative Example 3 differs from Example 1 primarily in that it lacks the addition of a compatibilizer. The resulting low compressive strength and high permeability are likely due to excessive cracking. Furthermore, the pore size retention after washing is poor, likely due to pore collapse and reduced porosity.

[0039] The main difference between Comparative Example 4 and Example 1 lies in the excessive amount of elastomeric block copolymer. This excessive amount of elastomeric block copolymer actually results in a lower rebound rate than in Example 1. This is likely because the excess polyurethane hinders cross-linking of the silicone rubber, thinning the pore walls, reducing structural stability, and easily causing phase separation, resulting in insufficient compressive strength.

[0040] The main difference between Comparative Example 5 and Example 1 is that it only contains porous nano-SiO2, and its air permeability is close to that of Example 1, but its compressive strength and water washability are lower.

[0041] The main difference between Comparative Example 6 and Example 1 is that the unmodified nanoparticles agglomerate and cause phase separation and pore collapse, resulting in a sharp drop in water permeability after washing and poor compressive strength.

[0042] Comparative Example 7 differs from Example 1 primarily in that no carbonate precursor solution was added. Both the air permeability and strength were lower than in Example 1. This is likely due to the dense microporous layer being primarily located near the block-modified nanoparticles and primarily resulting from carbonate formation on the surface of the block-modified nanoparticles by the carbonate precursor solution. This suggests that the addition of a carbonate precursor solution can provide a significant improvement.

[0043] The main difference between Comparative Example 8 and Example 1 is that no water and surfactant were added, and the air permeability and rebound rate were worse than those of Example 1. The main reason may be that the foaming reaction was incomplete and the lack of surfactant caused the bubbles to merge.

[0044] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A washable, highly breathable, slow-rebound silicone sponge, characterized in that: include: By weight, 10-20 parts of block modified nanoparticles, 50-60 parts of silica gel matrix, 10-20 parts of elastic block and 3-5 parts of compatibilizer; The washable, highly breathable, slow-rebound silicone sponge has a pore structure with an average pore size of 200-400 μm and a density of 0.5-1 g / cm 3 ; The preparation method of the block-modified nanoparticles comprises the following steps: Step (1), stirring and hydrolyzing the tetrabutyl titanate ethanol solution, adding ethyl orthosilicate according to the molar ratio of tetrabutyl titanate to ethyl orthosilicate of 1:3-8, adjusting the pH to 8-10, and ultrasonically treating to obtain a precursor, which is calcined at 400-600°C for 2-4h to obtain a TiO2@SiO2 core-shell structure; Step (2), mixing the template and ethanol in a mass ratio of 1:50-100, adding a sodium silicate solution until the molar ratio of the template to the sodium silicate is 1:5-10, then microwave-treating to form a porous silica precursor, and washing with an ethanol solution of hydrochloric acid to obtain porous nano-silica; Step (3), dispersing a mixture of TiO2@SiO2 core-shell structure and porous nano-silica in a mass ratio of 1:1-3 in 50-100 times the mass of a carbonate precursor solution, adjusting the pH to 8.5-9.5, reacting for 1-2 hours, adjusting the pH to 7-8, adding a silane coupling agent in an amount of 0.5-1% by mass of the mixture, stirring thoroughly, centrifuging and drying, and then dispersing in butanone to obtain a modified nanoparticle dispersion; Step (4): dissolving isophorone diisocyanate and polytetrahydrofuran in a butanone solvent at a ratio of NCO:OH=2-2.5:1, adding a catalyst, and reacting at 70-80°C for 2-3 hours to obtain a prepolymer, followed by adding a modified nanoparticle dispersion, reacting for 2-3 hours, filtering, washing, and drying to obtain block-modified nanoparticles.

2. The washable, highly breathable, slow-rebound silicone sponge according to claim 1, characterized in that: The silica gel matrix is a condensed two-component liquid silica gel, the elastic block body is a polyurethane block copolymer, and the compatibilizer is a mixture of an epoxy silane coupling agent and polyethylene glycol in a ratio of 1:0.5-1.

3. The washable, highly breathable, slow-rebound silicone sponge according to claim 1, characterized in that: In step (2), the template is hexadecyltrimethylammonium bromide.

4. The washable, highly breathable, slow-rebound silicone sponge according to claim 1, characterized in that: In step (3), the carbonate precursor solution is a sodium bicarbonate / calcium chloride mixed solution with a solute molar ratio of 1:1-1.2, and the silane coupling agent is KH560.

5. The washable, highly breathable, slow-rebound silicone sponge according to claim 1, characterized in that: The catalyst in step (4) is dibutyltin dilaurate.

6. The washable, highly breathable, slow-rebound silicone sponge according to claim 1, characterized in that: The cleaning process in step (4) is to rinse with butanone or acetone, then rinse with alcohol, and finally rinse with deionized water.

7. A method for preparing the washable, highly breathable, slow-rebound silicone sponge according to any one of claims 1 to 6, comprising the following steps: Step (a) preparing block-modified nanoparticles; Step (b) mixing the silica gel matrix, elastic block body, block modified nanoparticles and compatibilizer according to a proportion, adding 1%-3% of the total mass of water-soluble carbonate and 0.01%-0.1% of a surfactant, heating to 60-80° C., continuing to mix, adding 3%-5% of the total mass of an acid initiator, continuing to mix, pre-crosslinking at 60-80° C. for 30-60 minutes, then adding 0.5-1% of deionized water, mixing evenly, injecting into a mold, foaming and curing under controlled pressure in stages, washing, and drying to obtain a washable, highly breathable, slow-rebound silica gel sponge.

8. The method for preparing a washable, highly breathable, slow-rebound silicone sponge according to claim 7, wherein: The acid is citric acid or tartaric acid, and the process of controlling pressure and foaming in stages is as follows: Stage 1: Maintain at 2-3 MPa for 30-50 min; The second stage: reduce the pressure to 0.5-1 MPa and maintain for 20-30 minutes;   The third stage: rapid pressure relief to normal pressure.

9. The preparation method according to claim 7, wherein The cleaning process is repeated 2-3 times, the water absorption-squeezing process.

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