Breathable and washable silica gel chest bandage and preparation method thereof

Abstract

The application discloses a breathable and washable silica gel chest gauze and a preparation method thereof, and relates to the technical field of chest gauzes. The chest gauze comprises soft net-shaped polyurethane and a silica rubber composite material completely coated on the surface of the soft net-shaped polyurethane. The silica rubber composite material is made of the following components in parts by weight: 30-45 parts of silica rubber, 30-45 parts of silicone oil, 6-15 parts of modified silicon dioxide, 10-25 parts of light calcium carbonate, 0.1-2 parts of a structure control agent, 2-5 parts of a crosslinking agent, 0.01-0.1 parts of a reaction time-delaying agent and 0.05-0.5 parts of a platinum gold catalyst. The product has excellent air permeability, effectively improves the comfort and health of long-time wearing, significantly prolongs the service life of the product through special antibacterial design, reduces the generation of peculiar smell, and has washing durability and is convenient for daily cleaning and maintenance.

Description

Technical Field

[0001] This invention relates to the field of bra padding, specifically to a breathable and washable silicone bra padding and its preparation method. Background Technology

[0002] As a crucial filling component of underwear, bra padding significantly impacts the comfort, fit, and aesthetics of the garment. Currently, the main materials used in bra padding on the market include polyurethane foam, fiber cotton, or thermoplastic elastomers.

[0003] Polyurethane foam is currently the most widely used bra material. It is primarily made of polyether or polyester-based polyurethane foam and is characterized by its lightweight, moderate elasticity, and good moldability, providing some support and shaping effect for underwear. However, although polyurethane foam has a porous surface structure and theoretically possesses some breathability, its actual breathability remains poor in practice. More seriously, it is highly absorbent but poorly hydrophobic, making it difficult for water to drain after washing. In humid weather, it may take 3-5 days to dry completely. This persistently damp environment provides ideal conditions for the growth of bacteria, especially mold, making it a breeding ground for microorganisms. Furthermore, polyurethane foam is prone to yellowing, hardening, and cracking during use, and its lifespan typically does not exceed one year.

[0004] Fiberglass bra material is mainly made of polyester or other synthetic fibers through a thermal bonding process. Its advantages include extremely light weight, better breathability than polyurethane foam, and relatively low price. However, the biggest drawback of fiberglass is its poor resilience. After washing or prolonged wear, it is prone to irreversible deformation and sagging, causing the bra to lose its intended support. Furthermore, the pores between the fibers easily accumulate dust and dander, posing a hygiene risk if not thoroughly cleaned. Fiberglass also has a shorter lifespan, typically requiring replacement every six months.

[0005] Thermoplastic elastomer (TPE) bra materials have gained popularity in recent years. These materials are typically injection molded from materials such as SBS (styrene-butadiene-styrene) block copolymers or TPU (thermoplastic polyurethane elastomers), exhibiting excellent elastic recovery and shape retention. However, the biggest problem with thermoplastic elastomers is their near-non-breathability, which can lead to localized skin stuffiness and dampness after prolonged wear. Furthermore, these materials are prone to softening and deformation when exposed to heat or certain chemicals (such as perfumes and sunscreens), and their surface easily accumulates sweat and oil, requiring frequent cleaning but not being resistant to repeated washing.

[0006] CN113121776A discloses a sweat-absorbing and breathable polyurethane sponge, its preparation method, and a bra. The polyurethane sponge is prepared from the following raw materials in parts by weight: 100-160 parts of polyethylene glycol methyl ether, 20-70 parts of toluene diisocyanate, 8-15 parts of water, 2.3-4.8 parts of silicone oil, 0.2-1.6 parts of surfactant, 0.05-0.45 parts of amine catalyst, 3-7 parts of foaming agent, 3.2-8.6 parts of plant protein, and 6.4-15.6 parts of hydrophilic cellulose.

[0007] This material is difficult to clean, has poor shape retention after washing, makes it difficult to balance mechanical properties and comfort, has a short lifespan, and is prone to bacterial growth. Therefore, developing a breathable, washable, quick-drying, antibacterial, and long-lasting silicone bra pad is of significant practical importance for improving user experience, protecting women's health, and enhancing product market competitiveness. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a breathable and washable silicone bra pad and its preparation method. This product has excellent breathability, effectively improving comfort and health during prolonged wear; its unique antibacterial design significantly extends the product's lifespan and reduces odor generation; it also features washability and durability, facilitating daily cleaning and maintenance.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A breathable and washable silicone bra pad comprises a soft mesh polyurethane and a silicone rubber composite material completely covering the surface of the soft mesh polyurethane. By weight, the silicone rubber composite material is made of the following components: 30-45 parts silicone rubber, 30-45 parts silicone oil, 6-15 parts modified silica, 10-25 parts light calcium carbonate, 0.1-2 parts structure control agent, 2-5 parts crosslinking agent, 0.01-0.1 parts reaction delay agent, and 0.05-0.5 parts platinum catalyst.

[0011] Preferably, the silicone rubber is methylvinylsiloxane.

[0012] Preferably, the silicone oil is a vinyl silicone oil.

[0013] Preferably, the method for preparing the modified silica includes the following steps:

[0014] (1) Disperse nano-silica in an aqueous ethanol solution, then add KH550, stir the reaction, filter, wash and dry the product to obtain aminated nano-silica;

[0015] Silane coupling: The ethoxy group in the KH550 molecule first hydrolyzes in the presence of water to form silanol groups. These silanol groups then form a stable silicon-oxygen bond network through a condensation reaction with the hydroxyl groups on the silica surface. Water molecules are released during the condensation process, and organic chains with terminal amino groups are introduced onto the silica surface. These amino functional groups serve as active sites for subsequent reactions. This step successfully organically converts the inorganic silica surface and provides reactivity for further modification.

[0016] Preferably, in step (1), the concentration of the ethanol aqueous solution is 95 wt%; the ratio of nano silica, ethanol aqueous solution and KH550 is 10 g: 100-150 mL: 1-4 g.

[0017] Preferably, in step (1), the stirring reaction conditions are 65-80°C for 5-8 hours.

[0018] (2) Disperse aminated silica in PBS buffer, add EDC and NHS, stir to activate, then add L-histidine, stir to react, filter the product, wash with water, redisperse in deionized water, add silver nitrate solution in the dark, perform complexation reaction, centrifuge and wash the product to obtain intermediate silica.

[0019] Surface bifunctionalization: Using EDC and NHS as condensing agents, the system first activates the carboxyl group of L-histidine to form an active ester intermediate. Subsequently, some amino groups on the silica surface undergo nucleophilic addition reactions with this active ester, forming stable amide bonds. This covalently links the α-carboxyl group of histidine to the silica particle surface, while retaining the imidazole side chain. After the reaction, silver ions from the added silver nitrate solution coordinate with the imidazole group to form a stable complex, with the nitrogen atom of the imidazole ring serving as the main coordination site, thereby introducing antibacterial silver ions onto the surface.

[0020] Preferably, in step (2), the pH of the PBS buffer is 6-7, the concentration of the silver nitrate solution is 0.05-0.1 mol / L, and the ratio of the amounts of aminated silica, PBS buffer, EDC, NHS, L-histidine, deionized water, and silver nitrate is 10g: 100-150mL: 2-3g: 1-1.5g: 2-5g: 100-150mL: 1-3g.

[0021] Preferably, in step (2), the stirring reaction conditions are 30-40°C for 12-18 hours; the complexation reaction conditions are 4-7 hours at room temperature.

[0022] (3) Disperse intermediate silica in an aqueous ethanol solution, then add 2,3-epoxypropyltrimethylammonium chloride and potassium carbonate, heat the reaction, centrifuge, wash and dry the product to obtain modified nano silica.

[0023] Introducing quaternary ammonium salt groups: Under alkaline conditions, the unreacted surface amino groups retained in the first two steps act as nucleophiles, attacking the epoxy groups in the 2,3-epoxypropyltrimethylammonium chloride molecule, covalently attaching the positively charged quaternary ammonium salt groups to the silica surface. The final product surface possesses two synergistic antibacterial functional groups: silver ion-complexed histidine groups and quaternary ammonium salt groups. The former provides sustained-release antibacterial activity, while the latter provides contact bactericidal effects. These two mechanisms synergistically enhance the overall antibacterial performance of the material.

[0024] Preferably, in step (3), the volume ratio of ethanol to deionized water in the ethanol aqueous solution is 1 to 2:1; the ratio of intermediate silicon dioxide, ethanol aqueous solution, 2,3-epoxypropyltrimethylammonium chloride, and potassium carbonate is 10g:100 to 150mL:2 to 5g:0.5 to 1.2g.

[0025] Preferably, in step (3), the heating reaction conditions are to heat to 55-70°C and stir for 6-9 hours.

[0026] Preferably, the structuring control agent is a hydrocarbon-based silicone oil, the crosslinking agent is a hydrogen-containing silicone oil, the reaction delay agent is acetylenecycloethanol, and the platinum catalyst is a 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex.

[0027] This invention also claims a method for preparing the breathable and washable silicone bra pad, comprising the following steps: pretreating a soft mesh polyurethane at a temperature of 110–130°C for 10–30 minutes to remove odor; shaping the soft mesh polyurethane according to size and shape requirements; placing the raw materials in the formula by weight into a premixing reactor and stirring until homogeneous to obtain a liquid silicone rubber composite material; uniformly and completely covering the soft mesh polyurethane with the silicone rubber composite material; after cooling, placing it into a heating vulcanization device for vulcanization treatment at 130–150°C for 10–30 minutes to obtain the breathable and washable silicone bra pad.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The breathable and washable silicone bra pad of this invention adopts a double-layer composite structure design. A soft mesh polyurethane serves as the skeleton support, while the outer layer completely encapsulates a silicone rubber composite material, forming an ideal combination of soft touch and good elastic recovery. The silicone rubber coating layer is characterized by high-temperature stability, non-toxicity, and odorlessness, effectively isolating the polyurethane from oxygen and ultraviolet radiation, significantly improving the material's aging resistance, and preventing yellowing and deformation. Simultaneously, the hydrophobic properties of silicone rubber greatly reduce the composite material's water absorption rate, achieving quick-drying and easy-to-clean effects, thoroughly removing milk and sweat stains, and meeting food-grade safety standards. The optimized ratio of silicone rubber to silicone oil ensures the product's excellent flexibility and comfortable fit. Modified silica provides antibacterial properties while significantly improving the material's mechanical properties and thermal stability as a reinforcing filler. Light calcium carbonate, as a functional filler, effectively adjusts the product's density and hardness while reducing costs. A structure control agent precisely regulates the material's rheology and internal structure. Hydrogen-containing silicone oil, as a crosslinking agent, works synergistically with a reaction delay agent and a platinum catalyst to achieve controllable crosslinking network formation. This multi-component synergistic formulation design enables the product to maintain breathability while achieving excellent washability and durability, solving industry pain points such as traditional bra pads being easily deformed, not breathable, and difficult to clean.

[0030] 2. The modified nano-silica of this invention achieves highly efficient antibacterial dual-functionality and significantly enhanced dispersibility through three precisely controlled surface chemical modifications. The first step, a KH550 coupling reaction, introduces an organosilane layer and amino functional groups onto the silica surface, significantly improving the dispersion uniformity of the nano-silica in the matrix and effectively inhibiting aggregation. The second step achieves directional grafting of L-histidine through amide bonds to form a complex structure with silver ions, giving the material long-lasting sustained-release antibacterial properties. The third step introduces quaternary ammonium salt groups through an epoxy ring-opening reaction, providing contact-type rapid bactericidal function. This dual-functional synergistic bactericidal mechanism significantly improves the breadth of the antibacterial spectrum and antibacterial efficiency. The silver ion complexation provides sustained-release antibacterial activity, while the quaternary ammonium salt provides contact-type bactericidal effects. Together, they significantly extend the antibacterial duration. Furthermore, by firmly binding the antibacterial components to the surface of the nanocarrier, it solves the industry problem of traditional antibacterial materials easily precipitating in silicone rubber matrices, leading to a rapid decrease in antibacterial performance. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0032] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0033] The methyl vinyl siloxane was purchased from Anhui Sibao Organosilicon New Materials Co., Ltd., with the grade GX-172, a molecular weight of 660,000, and a vinyl content of 0.16 wt%.

[0034] Vinyl silicone oil was purchased from Ningbo Runhe High-Tech Materials Technology Co., Ltd., grade RH-Vi304;

[0035] The hydroxyl silicone oil was purchased from Jiangsu Quanli Chemical Co., Ltd., brand name QL-203D, with a hydroxyl content of 4-5 wt%.

[0036] The hydrogen-containing silicone oil was purchased from Jiangsu Quanli Chemical Co., Ltd., brand name QL-202, with a hydrogen content of 1-1.6 wt%.

[0037] Light calcium carbonate was purchased from Jiangxi Aote Fine Powder Co., Ltd., grade: DZ-1290;

[0038] Nano-silica was purchased from Jiangsu Huimai Powder Technology Co., Ltd.

[0039] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0040] (1) Disperse 10g of nano silica into 100-150mL of 95wt% ethanol aqueous solution, then add 1-4g of KH550, stir and react at 65-80℃ for 5-8h, filter, wash and dry the product to obtain aminated nano silica;

[0041] (2) Disperse 10g of aminated silica in 100-150mL of PBS buffer (pH=6-7), add 2-3g of EDC and 1-1.5g of NHS, stir to activate, then add 2-5g of L-histidine, stir to react at 30-40℃ for 12-18h, filter the product, wash with water, redisperse in 100-150mL of deionized water, add 1-3g of 0.05-0.1mol / L silver nitrate solution in the dark, stir to react at room temperature for 4-7h, centrifuge and wash the product to obtain intermediate silica;

[0042] (3) Disperse 10g of intermediate silica in 100-150mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 1-2:1), then add 2-5g of 2,3-epoxypropyltrimethylammonium chloride and 0.5-1.2g of potassium carbonate, heat to 55-70℃ and stir for 6-9h, centrifuge, wash and dry the product to obtain modified nano silica;

[0043] (4) Place the soft mesh polyurethane in a temperature environment of 110-130℃ for 10-30 min to remove odor, and shape the soft mesh polyurethane according to size and shape requirements; place 30-45 parts of silicone rubber, 30-45 parts of silicone oil, 6-15 parts of modified silica, 10-25 parts of light calcium carbonate, 0.1-2 parts of hydrocarbon silicone oil, 2-5 parts of hydrogen-containing silicone oil, 0.01-0.1 parts of acetylenecycloethanol, and 0.05-0.5 parts of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex in a premixing reactor and stir until uniform to obtain a liquid silicone rubber composite material; uniformly and completely cover the soft mesh polyurethane with the silicone rubber composite material, and after cooling, send it to a heating vulcanization device for vulcanization treatment at 130-150℃ for 10-30 min to obtain the breathable and washable silicone bra pad.

[0044] The present invention will be further described below through specific embodiments.

[0045] Example 1

[0046] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0047] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 4g of KH550, stir at 80℃ for 5h, filter, wash and dry the product to obtain aminated nano silica;

[0048] (2) Disperse 10g of aminated silica in 150mL of PBS buffer (pH=6.5), add 3g of EDC and 1.5g of NHS, stir to activate, then add 5g of L-histidine, stir at 40℃ for 12h, filter the product, wash with water, redisperse in 150mL of deionized water, add 3g of 0.1mol / L silver nitrate solution in the dark, stir at room temperature for 4h, centrifuge and wash the product to obtain intermediate silica;

[0049] (3) Disperse 10g of intermediate silica in 150mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 2:1), then add 5g of 2,3-epoxypropyltrimethylammonium chloride and 1.2g of potassium carbonate, heat to 70℃ and stir for 6h, centrifuge, wash and dry the product to obtain modified nano silica.

[0050] (4) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 4500g of methyl vinyl siloxane, 4500g of vinyl silicone oil, 1500g of modified silica, 2500g of light calcium carbonate, 200g of hydrocarbon silicone oil, 500g of hydrogen-containing silicone oil, 10g of acetylene cycloethanol, and 50g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 130°C for 10 minutes to obtain the breathable and washable silicone bra.

[0051] Example 2

[0052] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0053] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 3g of KH550, stir at 75℃ for 6h, filter, wash and dry the product to obtain aminated nano silica;

[0054] (2) Disperse 10g of aminated silica in 150mL of PBS buffer (pH=6.5), add 2.5g of EDC and 1.4g of NHS, stir to activate, then add 4g of L-histidine, stir at 36℃ for 14h, filter the product, wash with water, redisperse in 150mL of deionized water, add 2g of 0.1mol / L silver nitrate solution in the dark, stir at room temperature for 5h, centrifuge and wash the product to obtain intermediate silica;

[0055] (3) Disperse 10g of intermediate silica in 150mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 2:1), then add 4g of 2,3-epoxypropyltrimethylammonium chloride and 1g of potassium carbonate, heat to 65℃ and stir for 7h, centrifuge, wash and dry the product to obtain modified nano silica.

[0056] (4) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 4000g of methyl vinyl siloxane, 4000g of vinyl silicone oil, 1200g of modified silica, 2000g of light calcium carbonate, 140g of hydrocarbon silicone oil, 400g of hydrogen-containing silicone oil, 8g of acetylene cycloethanol, and 40g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 135°C for 15 minutes to obtain the breathable and washable silicone bra.

[0057] Example 3

[0058] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0059] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 2g of KH550, stir at 70℃ for 7h, filter, wash and dry the product to obtain aminated nano silica;

[0060] (2) Disperse 10g of aminated silica in 150mL of PBS buffer (pH=6.5), add 2.5g of EDC and 1.2g of NHS, stir to activate, then add 3g of L-histidine, stir at 34℃ for 16h, filter the product, wash with water, redisperse in 150mL of deionized water, add 2g of 0.1mol / L silver nitrate solution in the dark, stir at room temperature for 6h, centrifuge and wash the product to obtain intermediate silica;

[0061] (3) Disperse 10g of intermediate silica in 150mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 2:1), then add 3g of 2,3-epoxypropyltrimethylammonium chloride and 0.8g of potassium carbonate, heat to 60℃ and stir for 8h, centrifuge, wash and dry the product to obtain modified nano silica.

[0062] (4) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 3500g of methyl vinyl siloxane, 3500g of vinyl silicone oil, 900g of modified silica, 1500g of light calcium carbonate, 80g of hydrocarbon silicone oil, 300g of hydrogen-containing silicone oil, 4g of acetylene cycloethanol, and 20g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 140°C for 18 minutes to obtain the breathable and washable silicone bra.

[0063] Example 4

[0064] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0065] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 1g of KH550, stir at 65℃ for 5h, filter, wash and dry the product to obtain aminated nano silica.

[0066] (2) Disperse 10g of aminated silica in 150mL of PBS buffer (pH=6.5), add 2g of EDC and 1g of NHS, stir to activate, then add 2g of L-histidine, stir at 30℃ for 12h, filter the product, wash with water, redisperse in 150mL of deionized water, add 1g of 0.1mol / L silver nitrate solution in the dark, stir at room temperature for 4h, centrifuge and wash the product to obtain intermediate silica;

[0067] (3) Disperse 10g of intermediate silica in 150mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 2:1), then add 2g of 2,3-epoxypropyltrimethylammonium chloride and 0.5g of potassium carbonate, heat to 55℃ and stir for 9h, centrifuge, wash and dry the product to obtain modified nano silica.

[0068] (4) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 3000g of methyl vinyl siloxane, 3000g of vinyl silicone oil, 600g of modified silica, 1000g of light calcium carbonate, 10g of hydrocarbon silicone oil, 200g of hydrogen-containing silicone oil, 1g of acetylene cycloethanol, and 5g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 145°C for 20 minutes to obtain the breathable and washable silicone bra.

[0069] Comparative Example 1

[0070] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0071] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 4g of KH550, stir at 80℃ for 5h, filter, wash and dry the product to obtain aminated nano silica;

[0072] (2) Disperse 10g of aminated silica in 150mL of PBS buffer (pH=6.5), add 3g of EDC and 1.5g of NHS, stir to activate, then add 5g of L-histidine, stir at 40℃ for 12h, filter the product, wash with water, redisperse in 150mL of deionized water, add 3g of 0.1mol / L silver nitrate solution in the dark, stir at room temperature for 4h, centrifuge and wash the product to obtain intermediate silica;

[0073] (3) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 4500g of methyl vinyl siloxane, 4500g of vinyl silicone oil, 1500g of intermediate silica, 2500g of light calcium carbonate, 200g of hydrocarbon silicone oil, 500g of hydrogen-containing silicone oil, 10g of acetylene cycloethanol, and 50g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 130°C for 10 minutes to obtain the breathable and washable silicone bra.

[0074] Comparative Example 2

[0075] A method for preparing a breathable and washable silicone bra pad includes the following steps:

[0076] (1) Disperse 10g of nano silica into 150mL of 95wt% ethanol aqueous solution, then add 4g of KH550, stir at 80℃ for 5h, filter, wash and dry the product to obtain aminated nano silica;

[0077] (2) The soft mesh polyurethane was pretreated at 120°C for 20 minutes to remove odor. The soft mesh polyurethane was shaped according to size and shape requirements (thickness 30mm, width 500mm, length 1500mm). 4500g of methyl vinyl siloxane, 4500g of vinyl silicone oil, 1500g of aminated nano silica, 2500g of light calcium carbonate, 200g of hydrocarbon silicone oil, 500g of hydrogen-containing silicone oil, 10g of acetylene cycloethanol, and 50g of 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex were placed in a premixing reactor and stirred until uniform to obtain a liquid silicone rubber composite material. The silicone rubber composite material was uniformly and completely covered on the soft mesh polyurethane. After cooling, it was sent to a heating vulcanization device for vulcanization treatment at 130°C for 10 minutes to obtain the breathable and washable silicone bra.

[0078] Performance tests were conducted on the bra pads prepared in Examples 1-4 and Comparative Examples 1-2. Tensile strength and elongation at break were tested according to ASTM-D3574. SAG (sag parameter) value was tested according to ISO 2439-B. Thickness loss after 80,000 compressions and hardness loss after 80,000 compressions were tested according to ISO 3385:2014. Water absorption rate was tested according to GB / T 10299-2011, and antibacterial properties were tested according to GB 15979-2002. Specific data are shown in Table 1.

[0079] Table 1. Results of Chest Circumference Pad Performance Test

[0080]

[0081] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A breathable and washable silicone bra pad, comprising a soft mesh polyurethane and a silicone rubber composite material completely covering the surface of the soft mesh polyurethane, characterized in that, The silicone rubber composite material is made of the following components in parts by weight: 30-45 parts silicone rubber, 30-45 parts silicone oil, 6-15 parts modified silica, 10-25 parts light calcium carbonate, 0.1-2 parts structure control agent, 2-5 parts crosslinking agent, 0.01-0.1 parts reaction delay agent, and 0.05-0.5 parts platinum catalyst; The method for preparing the modified silica includes the following steps: (1) Disperse nano-silica in an aqueous ethanol solution, then add KH550, stir the reaction, filter, wash and dry the product to obtain aminated silica; (2) Disperse aminated silica in PBS buffer, add EDC and NHS, stir to activate, then add L-histidine, stir to react, filter the product, wash with water, redisperse in deionized water, add silver nitrate solution in the dark, perform complexation reaction, centrifuge and wash the product to obtain intermediate silica; (3) Disperse the intermediate silica in an aqueous ethanol solution, then add 2,3-epoxypropyltrimethylammonium chloride and potassium carbonate, heat the reaction, centrifuge, wash and dry the product to obtain modified silica.

2. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (1), the concentration of the ethanol aqueous solution is 95wt%; the ratio of nano silica, ethanol aqueous solution and KH550 is 10g: 100~150mL: 1~4g.

3. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (1), the stirring reaction conditions are 65~80℃ for 5~8h.

4. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (2), the pH of the PBS buffer is 6-7, the concentration of the silver nitrate solution is 0.05-0.1 mol / L, and the ratio of the amounts of aminated silica, PBS buffer, EDC, NHS, L-histidine, deionized water and silver nitrate is 10g: 100-150mL: 2-3g: 1-1.5g: 2-5g: 100-150mL: 1-3g.

5. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (2), the stirring reaction conditions are 30~40℃ for 12~18h; the complexation reaction conditions are 4~7h at room temperature.

6. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (3), the volume ratio of ethanol to deionized water in the ethanol aqueous solution is 1~2:1; the ratio of intermediate silicon dioxide, ethanol aqueous solution, 2,3-epoxypropyltrimethylammonium chloride and potassium carbonate is 10g:100~150mL:2~5g:0.5~1.2g.

7. The breathable and washable silicone bra pad according to claim 1, characterized in that, In step (3), the temperature reaction conditions are to raise the temperature to 55~70℃ and stir for 6~9 hours.

8. The breathable and washable silicone bra pad according to claim 1, characterized in that, The structuring control agent is a hydrocarbon-based silicone oil, the crosslinking agent is a hydrogen-containing silicone oil, the reaction delay agent is acetylenecycloethanol, and the platinum catalyst is a 1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex.

9. A method for preparing a breathable and washable silicone bra pad as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The soft mesh polyurethane is pretreated at 110-130°C for 10-30 minutes to remove odor. The soft mesh polyurethane is then shaped according to size and design requirements. The raw materials in the formula by weight are placed in a premixing reactor and stirred until homogeneous to obtain a liquid silicone rubber composite material. The silicone rubber composite material is then evenly and completely coated onto the soft mesh polyurethane. After cooling, it is placed in a heating vulcanization device and vulcanized at 130-150°C for 10-30 minutes to obtain the breathable and washable silicone bra pad.

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