โฟมที่อากาศผ่านได้และวิธีการเตรียมโฟมนั้น

Abstract

DEPCT67 คำขอนี้เกี่ยวข้องกับสาขาวิทยาการทางเทคนิคของโฟม,และโดยเฉพาะอย่างยิ่งเกี่ยวข้อง กับโฟมที่อากาศผ่านได้และวิธีการเตรียมมันโฟมที่อากาศผ่านได้ที่ถูกจัดให้มีในคำขอนี้ทำมาจาก วัตถุดิบต่อไปนี้ในส่วนโดยน้ำหนัก:60-90ส่วนของพอลิอีเทอร์พอลิออล;5-10ส่วนของพอลิเอส เทอร์พอลิออล;0.01-0.05ส่วนของสารทำให้โฟมเสถียร;8-20ส่วนของไอโซไซยาเนต;0.05-0.15 ส่วนของสารทำให้เกิดฟอง;0.01-0.1ส่วนของตัวเร่งปฏิกิริยา;และ1.2-3.2ส่วนของตัวเติมต้านการ เปลี่ยนรูปที่ไม่ชอบน้ำโฟมที่มีความสามารถอากาศผ่านได้ดีถูกได้รับมาโดยการผสมพอลิเอสเทอร์พอ ลิออล,พอลิอีเทอร์พอลิออล,ไอโซไซยาเนตและตัวเติมต้านการเปลี่ยนรูปที่ไม่ชอบน้ำภายใต้การช่วย ของตัวเร่งปฏิกิริยาและสารทำให้เกิดฟองการเติมตัวเติมต้านการเปลี่ยนรูปที่ไม่ชอบน้ำสามารถเพิ่ม ความแข็งแรงและสภาพไม่ชอบน้ำของโครงสร้างของโฟมเมื่อโฟมถูกใช้ในเสื้อชั้นในสตรีการดูดซึม น้ำของโฟมสามารถลดลงเมื่อมันถูกเปลี่ยนสำหรับการซักหลังหลายการซักโฟมไม่มีแนวโน้มสู่การ เปลี่ยนรูป;

Description

A kind of air-permeable foam and preparation method thereof Technical Field

[0001] The present application relates to the technical field of foam, and more specifically, to a permeable bubble foam and a preparation method thereof. Background Art

[0002] Foam has a series of characteristics such as elasticity, light weight, fast pressure-sensitive fixation, easy use, flexible bending, ultra-thin volume, and reliable performance. Therefore, it is often used in the core layer structure of products such as underwear, bras, cushions, and mattresses to provide support and support. It is also light, breathable, and comfortable to the touch.

[0003] But at the same time, foam also has excellent water absorption and water release properties. When foam is used in underwear and bras, since underwear and bras are often worn and washed in daily life, the foam is prone to deformation after repeated water absorption and release after long-term washing, affecting the foam's normal cushioning, shock absorption, support and other functions.

[0004] When foam is used in mattresses, seat cushions and other products, when the seat cushions and mattresses are wetted by aqueous solutions during use, the moisture penetrates into the foam. Due to the water absorption effect of the foam, the moisture is quickly absorbed into the interior of the foam. Therefore, the seat cushions, sheets, etc. must be aired. Since the foam contains moisture, it is difficult to completely dry the moisture inside the foam even if it is aired. After multiple water absorption and airing, the foam is likely to deform, reducing its supporting function and affecting the user experience of the seat cushions, mattresses, etc.

[0005] Summary of the Invention

[0006] In order to reduce the possibility of deformation of foam after repeated use, the present application provides a permeable foam and a preparation method thereof.

[0007] In a first aspect, the present application provides an air-permeable foam, comprising the following raw materials in parts by weight:

[0008] 60-90 parts of polyether polyol

[0009] 5-10 parts of polyester polyol

[0010] Foam stabilizer 0.01-0.05 parts

[0011] 8-20 parts of isocyanate

[0012] 0.05-0.15 parts of foaming agent

[0013] Catalyst 0.01-0.1 parts

[0014] 1.2-3.2 parts of hydrophobic anti-deformation filler.

[0015] The composition and usage ratio of the above raw materials are both preferred choices for this application. Among them, the polyester polyol is a solvent-free polyester polyol with an equivalent weight of 1063 and a viscosity of 11000 mPa·s at 23°C; it has good flexibility; and the polyether polyol is a solvent-free polyether polyol with a molecular weight of 2000-4000, a functionality of 2, a hydroxyl number of 28-56, and a viscosity of 370-971 mPa·s at 25°C, which has good water resistance, impact resistance, and low-temperature resistance. Therefore, when the polyester polyol and polyether polyol can combine their properties, the compound has good water resistance, flexibility, impact resistance, etc. When foamed, the foam obtained has advantages such as air permeability, resilience, and water resistance, and is not easily deformed after use.

[0016] Isocyanate has the function of promoting curing, foaming agent has the function of foaming, and catalyst can improve the lubricity of foam raw material system, so as to facilitate demolding after foaming is completed.

[0017] The isocyanate of the present application is preferably hexamethylene diisocyanate.

[0018] Since the main source of water absorption in foam is the pores of the foam, when water comes into contact with the surface of the foam, due to the weight of the water itself, the water will enter the interior of the foam along the pores. The pores of the foam are formed by foaming, so the distribution of the pores is intricate and complex, making it easy for water to be trapped. For this reason, the present application applies to add a hydrophobic anti-deformation filler. The hydrophobic anti-deformation filler not only plays a hydrophobic role, but also forms several prominent hydrophobic peaks on the surface of the foam skeleton after it is filled into the foam raw material system (see Figures 1 and 2). When water comes into contact with the foam, due to the effect of the hydrophobic peaks, it can block the speed of water entering the foam interior, reducing the rate of water absorption by the foam. In addition, the hydrophobic anti-deformation filler can also enhance the strength of the foam skeleton and reduce the possibility of deformation of the foam.

[0019] The working principle of the hydrophobic peak is similar to that of the papillae on the lotus leaf. As we all know, the lotus leaf is pure and untainted by mud because there are many tiny papillae on the surface of the lotus leaf. Each papilla and protrusion forms a "hill" on the surface of the lotus leaf. The bottom of the hill is filled with air, which forms an air film on the surface of the lotus leaf. In addition, there is a layer of waxy substances on the papillae. These waxy substances are hydrophobic. Therefore, when water droplets touch the lotus leaf, they will condense into round raindrops due to the tension of the air on the leaf and the hydrophobic effect, and then fall down. The purpose of "pursuing purity in mud" is achieved, which is also called the "lotus leaf effect."

[0020] Similarly, the hydrophobic anti-deformation filler added in this application forms several hydrophobic peaks on the surface of the foam skeleton, and there is air between adjacent hydrophobic peaks, thereby forming a waterproof film. When the foam comes into contact with water, the water first contacts the hydrophobic peaks on the foam skeleton. Since the distribution of pores in the foam is intricate, the skeleton formed is also intricately distributed, which also blocks the possibility of water entering the interior of the foam, thereby reducing the foam's absorption rate of water. At the same time, the hydrophobic peaks increase the roughness of the foam surface. When the foam is used in a bra, the rough surface of the foam makes it easy for its hot melt adhesive to bond it to the bra fabric stably. This improves the structural stability of the bra and reduces its deformation. Furthermore, the hydrophobic anti-deformation filler can also increase the strength of the foam skeleton and reduce the possibility of deformation of the foam.

[0021] In summary, the present application obtains foam with good air permeability by compounding polyester polyols, polyether polyols, isocyanates, water-resistant particles, etc., and with the assistance of catalysts and foaming agents. Due to the addition of hydrophobic anti-deformation fillers, the strength and hydrophobicity of the foam skeleton are enhanced. When the foam is used in bras, the foam is not easy to absorb water during the washing process, and the foam is not easy to deform after multiple washings. When the foam is used in products such as seat cushions, sprinkling water can reduce the possibility of the foam absorbing water into the inside, reduce the deformation of the seat cushion after multiple water absorption and drying, and improve its comfort and convenience.

[0022] Preferably, the hydrophobic anti-deformation filler is obtained by mixing an inorganic filler and a hydrophobic resin in a weight ratio of (4-7):10.

[0023] Inorganic fillers have filling and hydrophobic effects, are not easily compatible with water, and have a hydrophobic effect; hydrophobic resins also have hydrophobic and filling effects. When combined with inorganic fillers, they can play a synergistic role, improve the hydrophobicity and strength of the foam, and reduce the possibility of deformation of the foam.

[0024] Preferably, the inorganic filler is hollow microspheres, and the hollow microspheres are glass microspheres and / or ceramic microspheres.

[0025] The hollow microbeads used in this application have the advantages of being light and hydrophobic, so they can easily form a hydrophobic front on the surface of the foam. At the same time, they can also reduce the weight of the foam, making it less likely to absorb water and easier to float on the water surface. When washing underwear, the underwear is less likely to absorb water and sink, reducing the speed at which the foam absorbs water and reducing the possibility of deformation of the underwear.

[0026] At the same time, the filling effect of glass microspheres and ceramic microspheres improves the mechanical strength of the foam skeleton and reduces the possibility of its deformation.

[0027] Preferably, the specific gravity of the hollow microspheres is 0.5-0.9 g / cm 3 , the particle size is 10-20μm.

[0028] The hollow microspheres with the above specific gravity range and particle size are easy to form a good hydrophobic effect on the foam skeleton, further reducing the water absorption rate of the foam. Reducing the water absorption of the foam, thereby reducing the possibility of foam deformation.

[0029] Preferably, the hydrophobic resin comprises the following raw materials in parts by weight:

[0030] 5-10 parts polytetrafluoroethylene

[0031] 5-8 parts of polyvinylidene chloride

[0032] 1-5 parts of compatibilizer

[0033] Plasticizer 0.5-0.8 parts

[0034] Catalyst 0.1-0.8 parts.

[0035] Both polytetrafluoroethylene and polyvinylidene chloride are hydrophobic and have waxy surfaces. Therefore, the composite of the two produces a hydrophobic resin with good hydrophobicity. The compatibilizer not only improves the compatibility of polytetrafluoroethylene with polyvinylidene fluoride, but also improves the compatibility of the hydrophobic anti-deformation filler with the hydrophobic resin, and also improves the compatibility of the hydrophobic anti-deformation filler with the foam raw material system, thereby making the foam less susceptible to water absorption and deformation. When the resulting foam is used in bras or underwear, it is less susceptible to water absorption during repeated washing, reducing the possibility of water entrapment within the foam. Furthermore, the foam is less susceptible to deformation after washing, thereby improving the durability of the foam.

[0036] Preferably, the compatibilizer comprises the following raw materials in parts by weight:

[0037] PTW: 5-10 servings

[0038] Chlorinated polyethylene: 2-5 parts

[0039] Solid acrylic resin: 1-3 parts

[0040] Vinyl silicone resin: 0.5-1.2 parts.

[0041] PTW is PTW, an ethylene terpolymer launched by DuPont, is also a thermoplastic material. The PTW in this application is n-butyl acrylate-glycidyl acrylate, which has good compatibility. Chlorinated polyethylene is a polymer synthetic material made by chlorinating high-density polyethylene (HDPE). It is a white powder with good compatibility. Its average molecular weight is 50,000-250,000 and the chlorine content is 30-40%. The average molecular weight of solid acrylic resin is 40,000-85,000, with good flexibility and adhesion. Vinyl silicone resin has good film-forming properties, moderate flexibility, and good water repellency. The vinyl content is 1.2%-2.7% and it appears as a white, loose powder.

[0042] The compatibilizer obtained by compounding PTW, chlorinated polyethylene, solid acrylic resin and vinyl silicone resin in the present application has a good compatibility effect and can improve the compatibility of the hydrophobic resin raw material system; the inorganic fillers are glass microbeads and ceramic microbeads, which are all inorganic substances and are not easy to mix with polymers. The compatibilizer composed of the above raw materials can stably adhere to the surface of the inorganic filler, improve its lipophilicity, and make it easy to mix with the hydrophobic resin.

[0043] Preferably, the hydrophobic anti-deformation filler is prepared by the following method:

[0044] 1) Weighing PTW, chlorinated polyethylene, solid acrylic resin, and epoxy acrylic resin in parts by weight, and mixing them uniformly to obtain a compatibilizer;

[0045] 2) Weigh polytetrafluoroethylene in parts by weight, heat until melted, cool to 200-250° C., add polyvinylidene chloride and plasticizer, mix evenly, cool to 165-185° C., add compatibilizer, and stir evenly to obtain a hydrophobic resin;

[0046] 3) Weigh the inorganic filler according to parts by weight and add it to the hydrophobic resin, stir for 15-25 minutes to obtain a hydrophobic material, and grind the hydrophobic material to obtain a hydrophobic anti-deformation filler.

[0047] In the above process, the melting point of polytetrafluoroethylene is relatively high, so it is necessary to heat it to melt, and then cool it down before adding polyvinyl chloride and plasticizer. If the temperature is too high, it will cause some raw materials to decompose or burn. The raw material system of the hydrophobic anti-deformation filler prepared by the above process in this application is evenly dispersed. When it is used in the raw material system of foam, the hydrophobic peak formed on the surface of the foam skeleton has good hydrophobicity, thereby improving the hydrophobicity of the foam, and at the same time improving the mechanical strength of the foam skeleton, so that the foam in the underwear is not easy to deform after long-term use, thereby improving the quality and practicality of the underwear. At the same time, after the foam of this application is used for the cushion, after the cushion is sprinkled with water, the foam will not quickly absorb water into the inside of the foam. In this way, when handling the cushion, the water on the surface can be directly wiped dry. If there is too much water, it can be slightly ventilated and aired to reduce the moisture trapped inside the foam, which affects the comfort of the cushion. At the same time, the mechanical strength of the foam skeleton is enhanced, and the possibility of the foam deformation during use is reduced.

[0048] Preferably, the particle size of the hydrophobic anti-deformation filler is 400-800 mesh.

[0049] By using hydrophobic, anti-deformation fillers of varying particle sizes, the foam's raw material system is filled to create several hydrophobic peaks on the surface of the foam skeleton, further reducing the foam's hydrophobicity. Furthermore, the foam's air permeability is 70-90% (tested in accordance with GB / T10655-2003). This also enhances the mechanical strength of the foam skeleton, reducing the likelihood of deformation.

[0050] Preferably, the step 3) further comprises drawing the hydrophobic material to form fiber filaments with a diameter of 5-10 μm, and then shearing the fiber filaments to form fiber filaments with a length of 30-50 μm to obtain the hydrophobic anti-deformation filler.

[0051] By drawing the hydrophobic material into fibers with a diameter of 5-10 μm and a length of 30-50 μm, this invention can also form strip-shaped hydrophobic peaks (a fluffy effect) on the foam skeleton, further reducing the hydrophobicity of the foam. This can also enhance the mechanical strength of the foam skeleton and reduce the possibility of foam deformation.

[0052] In a second aspect, a method for preparing air-permeable foam is provided, characterized in that it comprises the following steps: weighing polyether polyol, polyester polyol, and foaming agent in parts by weight and mixing them evenly to obtain mixture A; then weighing isocyanate, foam stabilizer, and catalyst and mixing them evenly to obtain mixture B; heating mixture A to 55-75°C, adding mixture B while stirring, and after addition, reacting for 1-3 hours to obtain a reaction mass, placing the reaction mass in a mold, and obtaining foam after aging, demolding, and standing.

[0053] The foam produced by the above process has hydrophobicity and mechanical strength. When used in underwear or bras, it is less likely to deform after repeated washing.

[0054] In summary, this application has the following beneficial effects:

[0055] 1. The present application obtains a foam with good air permeability by compounding polyester polyol, polyether polyol, isocyanate, water-resistant particles, etc., and with the assistance of a catalyst and a foaming agent. Due to the addition of hydrophobic anti-deformation fillers, several hydrophobic peaks are formed on the surface of the foam skeleton, thereby reducing the hydrophobicity of the foam. When the foam is used in a bra, it is not easy to absorb water during the cleaning process, thereby reducing the problem of deformation caused by long-term washing when the foam is used in a bra. When the foam is used in products such as seat cushions, after sprinkling water, it can reduce the possibility of the foam absorbing water into the interior, thereby improving its comfort and convenience.

[0056] 2. The compatibilizer obtained by compounding PTW, chlorinated polyethylene, solid acrylic resin and vinyl silicone resin in this application has a good compatibility effect and can improve the compatibility of the hydrophobic resin raw material system; it can also improve the lipophilicity of the inorganic filler, making it easy to mix with the hydrophobic resin. When the foam prepared is used in underwear, the hydrophobicity of the foam is reduced when the underwear is changed, thereby reducing the possibility of deformation of the foam. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a schematic structural diagram of the foam of the present application.

[0058] Figure 2 is a schematic diagram of the enlarged structure of the foam.

[0059] Figures 3 to 5 are diagrams showing the experimental process of the foam of the present application and ordinary foam. DETAILED DESCRIPTION

[0060] The present application is further described in detail below with reference to Figures 1-5 and embodiments.

[0061] Preparation example of hydrophobic anti-deformation filler

[0062] Preparation Example 1

[0063] A preparation example of a hydrophobic anti-deformation filler comprises the following steps:

[0064] 1) Weigh 2 kg of PTW, 5 kg of chlorinated polyethylene, 1 kg of solid acrylic resin, and 7 kg of epoxy acrylic resin, place them in a high-speed mixer and mix them evenly to obtain a compatibilizer.

[0065] 2) Weigh 5 kg of polytetrafluoroethylene and place it in a kneader. Heat it to 323°C to completely dissolve the polytetrafluoroethylene. Cool it to 230°C, then add 8 kg of polyvinylidene chloride and 0.5 kg of plasticizer. Stir for 30 minutes to mix the polyvinylidene chloride, plasticizer and polytetrafluoroethylene. Cool it to 185°C, add 1 kg of compatibilizer, and stir for 40 minutes to mix them thoroughly to obtain a hydrophobic resin.

[0066] 3) Weigh 24 kg of inorganic filler and add it to the hydrophobic resin, stir for 20 minutes, and cool to 25° C. to obtain a hydrophobic material. Place the hydrophobic material in a grinder for crushing, and pass it through a 500-mesh sieve to obtain a hydrophobic anti-deformation filler.

[0067] The inorganic filler is composed of ceramic microspheres and glass microspheres in a weight (kg) ratio of 1:1.

[0068] Preparation Example 2-3

[0069] Preparation Example 2-3 differs from Preparation Example 1 in that the amounts of raw materials used are different, as shown in Table 1.

[0070] Amount of raw materials used in Preparation Examples 1-3 (kg)

[0071] Preparation Example 4

[0072] The difference between Preparation Example 4 and Preparation Example 2 is that 3) also includes placing the hydrophobic material into a twin-screw extruder for spinning to form fiber filaments with a wire diameter of 8 μm, and then placing it into a shearing machine for shearing to form fiber filaments with a length of 40 μm to obtain a hydrophobic anti-deformation filler.

[0073] Preparation Comparative Example

[0074] Preparation Comparative Example 1

[0075] Preparation Example 1 is different from Comparative Example 1 in that an equal amount of polytetrafluoroethylene is replaced by polyvinylidene chloride.

[0076] Preparation Comparative Example 2

[0077] The difference between the preparation of Comparative Example 2 and Comparative Example 1 is that an equal amount of polyvinylidene chloride is replaced by polytetrafluoroethylene.

[0078] Preparation Comparative Example 3

[0079] The difference between Comparative Example 3 and Comparative Example 1 is that there is no inorganic filler. The preparation method of the hydrophobic anti-deformation filler is:

[0080] 1) Weigh 2 kg of PTW, 5 kg of chlorinated polyethylene, 1 kg of solid acrylic resin, and 7 kg of epoxy acrylic resin, place them in a high-speed mixer and mix them evenly to obtain a compatibilizer;

[0081] 2) Weigh 5 kg of polytetrafluoroethylene and place it in a kneader. Heat it to 323 ° C to completely dissolve the polytetrafluoroethylene, cool it to 230 ° C, add 8 kg of polyvinylidene chloride and 0.5 kg of plasticizer, stir for 30 minutes, mix the polyvinylidene chloride, plasticizer and polytetrafluoroethylene, cool it to 185 ° C, add 1 kg of compatibilizer, stir for 40 minutes to mix them thoroughly, and cool it to 25 ° C; obtain a hydrophobic material, put the hydrophobic material into a grinder for grinding, and pass it through a 500-mesh sieve to obtain a hydrophobic anti-deformation filler.

[0082] Preparation Comparative Example 4

[0083] The difference between the preparation of comparative example 4 and comparative example 1 is that there is no hydrophobic resin. The preparation method of the hydrophobic anti-deformation filler is as follows: ceramic microbeads and glass microbeads with a weight (kg) ratio of 1:1 are ground for 1 hour, and passed through a 500-mesh sieve to obtain a hydrophobic anti-deformation filler.

[0084] Example

[0085] Example 1

[0086] A preparation method for air-permeable foam comprises the following steps: weighing 90 kg of polyether polyol, 5 kg of polyester polyol, and 0.10 kg of a foaming agent, and mixing them evenly to obtain a mixture A; then weighing 20 kg of isocyanate, 0.01 kg of a foam stabilizer, and 0.05 kg of a catalyst, and mixing them evenly to obtain a mixture B; placing the mixture A into a reactor, heating it to 60° C., adding the mixture B while stirring, and after the mixture B is completely added, reacting for 2 hours to obtain a reaction mass; weighing 3.2 kg of a hydrophobic anti-deformation filler, adding it to the reaction mass, and stirring evenly to obtain a mixture C; placing the mixture C in a mold, and subjecting it to aging, demoulding, and standing to obtain foam.

[0087] Wherein, the isocyanate is hexamethylene diisocyanate; the blowing agent is water; the catalyst is stannous octoate catalyst; the foam stabilizer is silicone oil; and the hydrophobic anti-deformation filler is obtained from Preparation Example 1.

[0088] Example 2

[0089] The difference between Example 2 and Example 1 is that the amounts of raw materials used are different, such as 80 kg of polyether polyol, 8 kg of polyester polyol, 15 kg of isocyanate, and 2.2 kg of hydrophobic anti-deformation filler.

[0090] Example 3

[0091] The difference between Example 2 and Example 1 is that the amounts of raw materials used are different, such as 70 kg of polyether polyol, 5 kg of polyester polyol, 12 kg of isocyanate, and 1.2 kg of hydrophobic anti-deformation filler.

[0092] Examples 4-10

[0093] The difference between Examples 4-10 and Example 2 is that the sources of the hydrophobic anti-deformation fillers are different, as shown in Table 2.

[0094] Table 2 Sources of hydrophobic anti-deformation fillers of Examples 4-10

[0095] Comparative Example

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 1 is that the particle size of the hydrophobic anti-deformation filler is 3000 mesh.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 1 is that the hydrophobic anti-deformation filler is replaced with polyether polyol in equal amount, and finally a common foam is obtained.

[0100] Performance testing

[0101] The foams obtained in Examples 1-10 and Comparative Examples 1-2 were subjected to the following performance tests.

[0102] Detection method / test method

[0103] 1. Water absorption test

[0104] The foam obtained in Example 4 and Comparative Example 2 was cut into pieces with an area of ​​18 cm 2 3-5, the foam of Example 4 is first placed in water. At this time, the foam of the present application floats on the water surface (as shown in FIG3), and then the ordinary foam of Comparative Example 2 is placed in water. At this time, the ordinary foam of Comparative Example 2 begins to absorb water and sink, while the foam of the present application still floats on the water surface (see FIG4); when the ordinary foam of Comparative Example 2 sinks to the bottom of the water, the foam of the present application still floats, which indicates that the foam of the present application has good hydrophobicity, making it difficult for the foam to absorb water into the interior.

[0105] 2. Extensibility test

[0106] The foams obtained in Examples 1-10 and Comparative Examples 1-2 were respectively hot-pressed to form 34A cups for bras; the distance between the highest point of the cup protrusion and the horizontal plane was measured as H1, and the cups were marked and placed in a washing machine. The washing machine's quick wash button was pressed and the washing machine was washed for 15 minutes (including adding water for 2 minutes, washing for 10 minutes, and dehydrating for 3 minutes). The washing was repeated for a total of 20 washes. The cups were then removed, air-dried, and left to dry for 24 hours. The distance between the highest point of the cup protrusion and the horizontal plane was measured as H2; the expansion change rate a was calculated as [(H1-H2) / H2]*100%. The larger the a, the more easily the cups absorb water and deform. The experimental data are shown in Table 3.

[0107] 3. Water absorption test

[0108] The test was conducted with reference to Section 6.2.3 of the national standard GB / T18944.1-2003. The dimensions of the foam test specimen were 50 mm (length) × 50 mm (width) × 15 mm (thickness). The test pressure was 17 kPa, and the specimen was immersed in distilled water for 3 minutes. The pressure was released, and the specimen was immersed in distilled water for 3 minutes. The laboratory environment temperature was 25°C and the humidity was 50%. A water absorption vacuum device model CXK-A was used for the test. The test data are shown in Table 3.

[0109] 4. Air permeability

[0110] The test was carried out with reference to GB / T 10655-2003. The specific data are shown in Table 3.

[0111] Table 3 Experimental data of Examples 1-10 and Comparative Examples 1-2

[0112] As can be seen from the table above, the water absorption rate increased from 3.25% (Example 1) to 4.65% (Example 2). This indicates that when the mesh size of the hydrophobic anti-deformation filler is as high as 3000 mesh, the hydrophobic front formed is not obvious, the hydrophobic effect is poor, and the foam is prone to water absorption. Compared with Example 1, the water absorption rate and expandability of Comparative Example 2 are both higher than those of Example 1, indicating that the addition of hydrophobic anti-deformation filler can improve the hydrophobicity of the foam, reduce the foam's water absorption rate, and reduce the possibility of foam deformation.

[0113] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

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