TWI907045B - Waterproof and breathable silicone leather and its preparation method - Google Patents

Abstract

This invention provides a waterproof and breathable silicone leather and its preparation method. The method includes steps for preparing a top adhesive, a base adhesive, a top layer, a bottom layer, and a release paper peeling step, so that the resulting silicone leather includes a top layer, a bottom layer disposed on the surface of the top layer, and a base fabric covering the surface of the bottom layer; the top layer and the bottom layer are mechanically foamed to form irregular microchannels, and... The surface is formed with waterproof and breathable pores, which bond the bottom layer to the top layer and conduct the waterproof and breathable pores, so that the microchannels in the bottom layer are connected to the microchannels in the top layer; thereby, through the good waterproof performance of the silicone material itself, combined with mechanical foaming technology, a balance between waterproof and breathable performance is achieved, thereby improving the comfort, weather resistance and wear resistance.

Description

Waterproof and breathable silicone leather and its preparation method

This invention relates to the field of artificial leather technology, and in particular to waterproof and breathable silicone leather and its preparation method.

With the rapid development of modern industry and technology, artificial leather is widely used in daily life, such as in shoemaking, clothing, furniture, and automotive interiors. Artificial leather is mainly made from synthetic materials through chemical treatment and machining, offering advantages such as low cost, ease of processing, and customizability. However, existing artificial leathers have some shortcomings in terms of waterproof and breathable properties. Currently, common artificial leathers on the market mainly include polyvinyl chloride (PVC) leather, polyurethane (PU) leather, and silicone leather.

PVC leather is inexpensive, has a mature production process, and is easy to process, but it has poor breathability, may harden and become brittle after prolonged use, and is less environmentally friendly, causing some pollution. PU leather has a texture closer to natural leather, is soft, and has high abrasion resistance, but its breathability and waterproof performance are limited. Prolonged contact with moisture may cause it to age and decompose, also impacting the environment. Silicone leather has good high-temperature resistance, low-temperature resistance, and aging resistance, and is relatively environmentally friendly, but its production cost is high, and its breathability and waterproof performance still need improvement in some applications.

While the aforementioned existing technologies possess certain advantages in various aspects, they still fall short in balancing waterproofing and breathability. Traditional synthetic leathers often sacrifice breathability in pursuit of waterproofing, leading to reduced comfort during use, particularly noticeable in footwear and apparel. Furthermore, existing PVC and PU leathers have negative environmental impacts during production and disposal; with increasing environmental awareness, the market demand for environmentally friendly materials is becoming increasingly urgent. Some synthetic leathers are also prone to aging, discoloration, and cracking after prolonged use, affecting the product's appearance and lifespan.

Therefore, developing a waterproof and breathable silicone leather and its manufacturing method can meet the market demand for high-performance, environmentally friendly and durable materials, and has important practical significance and broad application prospects.

In view of the aforementioned technical problems, the present invention aims to provide a waterproof and breathable silicone leather and its preparation method. Utilizing the inherent excellent waterproof properties of silicone materials, combined with mechanical foaming technology, a balance between waterproof and breathable performance can be achieved, improving user comfort. This results in the silicone leather of the present invention possessing excellent waterproof and breathable properties, and significant improvements in environmental performance, service life, and durability. Furthermore, silicone materials are environmentally friendly, with minimal environmental impact during production and disposal, meeting market demand for green materials. The silicone leather also exhibits high weather resistance and abrasion resistance, and is less prone to aging and cracking even after prolonged use, extending the product's lifespan.

To achieve the above objectives, the present invention provides a waterproof and breathable silicone leather, comprising: a top layer having a first surface and a second surface opposite to the first surface; the interior of the top layer is mechanically foamed to form irregularly shaped microchannels, the microchannels connecting to the first surface and the second surface to form waterproof and breathable pores; a bottom layer having a third surface and a fourth surface opposite to the third surface; the interior of the bottom layer is mechanically foamed to form another irregularly shaped microchannel, the other microchannel connecting to the third surface and the fourth surface to form another waterproof and breathable pore; the third surface of the bottom layer is bonded to the second surface of the top layer, the other waterproof and breathable pore on the third surface is conductive to the waterproof and breathable pore on the second surface, and the other microchannel of the bottom layer connects to the microchannel of the top layer; A base fabric is applied to the fourth surface of the substrate.

According to embodiments of the present invention, the pore sizes of the microchannels and the waterproof and breathable pores in the surface layer can be independently from 0.2μm to 5μm. In one embodiment, the pore sizes of the microchannels and the waterproof and breathable pores in the surface layer can be independently 0.2µm, 0.5µm, 0.8µm, 1.1µm, 1.4µm, 1.7µm, 2µm, 2.3µm, 2.6µm, 2.9µm, 3.2µm, 3.5µm, 3.8µm, 4.1µm, 4.4µm, 4.7µm, or 5µm, but are not limited thereto; each of the above specific values can be used as an endpoint value of another range. Preferably, the pore size of the microchannel and the waterproof and breathable pore of the surface layer can be independently approximately 2µm.

According to the embodiments of the present invention, the pore sizes of the other microchannel and the other waterproof and breathable pore in the substrate can be independently from 0.2μm to 5μm. Specifically, the pore sizes of the other microchannel and the other waterproof and breathable pore in the substrate can be independently 0.2µm, 0.5µm, 0.8µm, 1.1µm, 1.4µm, 1.7µm, 2µm, 2.3µm, 2.6µm, 2.9µm, 3.2µm, 3.5µm, 3.8µm, 4.1µm, 4.4µm, 4.7µm or 5µm; but not limited thereto, each of the above specific values can be used as an endpoint value of another range. More specifically, the pore size of the other microchannel and the other waterproof and breathable pore in the bottom layer can each be independently approximately 2µm.

According to the embodiments of the present invention, the thickness of the silicone leather can be from 0.09 mm to 0.22 mm. Specifically, the thickness of the silicone leather can be 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.20 mm, 0.21 mm, or 0.22 mm; but is not limited thereto, each of the above specific values can be used as an endpoint value of another range.

According to the embodiments of the present invention, the thickness of the surface layer can be from 0.02 mm to 0.07 mm. Specifically, the thickness of the surface layer can be 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm or 0.07 mm; but not limited thereto, each of the above specific values can be used as an endpoint value of another range.

According to the embodiments of the present invention, the thickness of the substrate can be from 0.07 mm to 0.15 mm. Specifically, the thickness of the substrate can be 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm or 0.15 mm; but not limited thereto, each of the above specific values can be used as an endpoint value in another range.

According to the embodiments of the present invention, the thickness ratio of the surface layer to the bottom layer can be 2:7 to 7:15.

According to an embodiment of the present invention, the surface layer, by weight, may include: liquid silicone, 100 parts by weight; talc, 5 to 10 parts by weight; hydrogen-containing crosslinking agent, 2 to 6 parts by weight; and platinum catalyst, 1 to 1.2 parts by weight.

According to an embodiment of the present invention, the substrate, by weight, may include: liquid silicone, 100 parts by weight; vinyl silicone oil, 4 to 10 parts by weight; aluminum hydroxide, 80 to 100 parts by weight; hydrogen-containing crosslinker, 2 to 6 parts by weight; and platinum catalyst, 1 to 1.2 parts by weight.

According to the embodiments of the present invention, the tactile feel of the surface layer is improved by adding talc powder, giving the surface layer a smooth feel and scratch resistance. In addition, by adding talc powder to the liquid silicone, the material properties of talc powder, which has a significantly higher surface tension than liquid silicone and thus low compatibility between the two, can be utilized. After mechanical foaming processing, a high-porosity foam structure can be formed, effectively improving the waterproof and breathable properties of the silicone leather of the present invention.

In one embodiment, the talc powder in the surface layer may be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight; but not limited thereto, each of the above specific values may be used as an endpoint value of another range.

In one embodiment, the average particle size (D50) of the talc powder in the surface layer can be from 2.6 micrometers (µm) to 3.5 µm. Specifically, the average particle size (D50) of the talc powder can be 2.6 µm, 2.7 µm, 2.8 µm, 2.9 µm, 3 µm, 3.1 µm, 3.2 µm, 3.3 µm, 3.4 µm, or 3.5 µm; but not limited thereto, each of the above specific values can be used as an endpoint of another range.

According to the present invention, by adding aluminum hydroxide to the liquid silicone constituting the substrate, the material properties of aluminum hydroxide, which has a significantly higher surface tension than liquid silicone and thus low compatibility between the two, can be utilized. After mechanical foaming, the substrate forms a high-porosity foam structure, and the substrate and the top layer are bonded together to form an organosilicon leather with waterproof, breathable, and flame-retardant properties.

In one embodiment, the aluminum hydroxide in the bottom layer may be 80 parts by weight, 83 parts by weight, 86 parts by weight, 89 parts by weight, 92 parts by weight, 95 parts by weight, 98 parts by weight, or 100 parts by weight; but not limited thereto, each of the above specific values may be used as an endpoint value in another range.

In one embodiment, the average particle size (D50) of the bottom layer of aluminum hydroxide can be from 2.6 micrometers (µm) to 3.5 µm. Specifically, the average particle size (D50) of the aluminum hydroxide can be 2.6 µm, 2.7 µm, 2.8 µm, 2.9 µm, 3 µm, 3.1 µm, 3.2 µm, 3.3 µm, 3.4 µm, or 3.5 µm; but not limited thereto, each of the above specific values can be used as an endpoint value of another range.

In one embodiment, the underlying vinyl silicone oil may be 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight; however, it is not limited to these, and each of the above specific values can be used as an endpoint of another range. The vinyl silicone oil is a divinyl-terminated polydimethylsiloxane, or a methylvinyl polysiloxane with vinyl groups in the molecular chain. Besides the possible difference in the number and position of vinyl groups, another difference between liquid silicone and vinyl silicone oil is that the molecular weight or viscosity of liquid silicone is greater than that of vinyl silicone oil.

According to an embodiment of the present invention, by adding appropriate amounts of hydrogen-containing crosslinking agent and platinum catalyst to the substrate, the liquid silicone and other additives are cured to form an organosilicon leather with flexible properties.

In one embodiment, the hydrogen-containing crosslinker in the top layer and the bottom layer may each be independently 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, or 6 parts by weight; however, this is not a limitation, and each of the above specific values may be an endpoint value of another range. The hydrogen-containing crosslinker may be poly(methyl hydrogen siloxane) (PMHS).

In one embodiment, the hydrogen-containing crosslinker used between the top layer and the bottom layer is a hydrogen-containing crosslinker with a hydrogen content of 0.5 wt% to 1.0 wt%. Specifically, the hydrogen content of the hydrogen-containing crosslinker can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1 wt%; however, it is not limited to these values, and each of the above specific values can be used as an endpoint value of another range.

In one embodiment, the platinum catalyst in the top layer and the bottom layer may each be independently 1 part by weight, 1.1 parts by weight, or 1.2 parts by weight; however, this is not a limitation, and each of the above specific values can be used as an endpoint of another range. The platinum catalyst may be chloroplatinic _acid ( _H₂PtCl₆ ).

In one embodiment, the concentration of platinum catalyst used in the top and bottom layers can be 500 ppm to 5000 _ppm of chloroplatinic acid ( _H₂PtCl₆ ). Specifically, the concentration of the platinum catalyst can be 500 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm, 3500 ppm, 4000 ppm, 4500 ppm, or 5000 ppm; but is not limited thereto, each of the above specific values can be used as an endpoint of another range.

According to the embodiments of the present invention, by weight, 0.5 to 3 parts by weight of color paste may be added separately to the top layer and the bottom layer to adjust the color of the waterproof and breathable silicone leather.

In one embodiment, the color paste of the top layer and the bottom layer may each be independently 0.5 parts by weight, 0.8 parts by weight, 1.1 parts by weight, 1.4 parts by weight, 1.7 parts by weight, 2 parts by weight, 2.3 parts by weight, 2.6 parts by weight, 2.9 parts by weight, or 3 parts by weight; but not limited thereto, each of the above specific values may be used as an endpoint value of another range.

According to the embodiments of the present invention, the base fabric can be selected from one of the following: knitted leather base fabric, machine-woven leather base fabric, and microfiber leather base fabric. Specifically, the material of the aforementioned leather base fabric can be one of the following: polyester-cotton blend base fabric, pure polyester base fabric, pure cotton base fabric, and polyester-viscose fiber blend base fabric.

In one embodiment, the weight of the base fabric can be from 60 grams (g) to 500g. Specifically, the weight of the base fabric can be 60g, 90g, 120g, 150g, 180g, 210g, 240g, 270g, 300g, 330g, 360g, 390g, 420g, 450g, 480g, or 500g; but is not limited thereto, each of the above specific values can be used as an endpoint of another range.

This invention also provides a method for preparing waterproof and breathable silicone leather, the method comprising the following steps: Top adhesive preparation step: by weight, 100 parts of liquid silicone and 5 to 10 parts of talc are mechanically foamed to form a first foam; then 2 to 6 parts of a hydrogen-containing crosslinking agent and 1 to 1.2 parts of a platinum catalyst are added and mixed evenly; Base adhesive preparation step: by weight, 100 parts of liquid silicone and 4 to 10 parts of vinyl silicone oil are mixed and stirred to form a foam structure mixture, then 80 to 100 parts of aluminum hydroxide (Al(OH) ₃₎ are added to the foam structure mixture. Mechanical foaming is performed to form a second foam; then 0.2 to 0.6 parts of hydrogen-containing crosslinker and 0.1 to 0.12 parts of platinum catalyst are added and mixed evenly; Surface layer preparation steps: The first foam body is coated onto the surface of a release paper with a thickness of 0.02 mm to 0.07 mm to form a first foam layer; the first foam layer and the release paper are transferred to a tunnel oven for curing and molding. The first half of the total curing and molding time is defined as the pre-curing stage, and the second half of the total time is defined as the post-curing stage. The heating temperature in the pre-curing stage is 80°C to 90°C, and the heating temperature in the post-curing stage is 120°C to 150°C; the first foam layer is cured and molded into a surface layer with a plurality of microchannels formed inside. Base layer preparation steps: The second foam is scraped onto the surface of the top layer to form a second foam layer with a thickness of 0.07 mm to 0.15 mm. Immediately afterwards, a base fabric is covered onto the surface of the second foam layer. The second foam layer, the base fabric, the top layer, and the release paper are then transferred to the tunnel oven for curing and molding. The first half of the total curing and molding time is defined as the pre-curing stage, and the second half is defined as the post-curing stage. The heating temperature in the pre-curing stage is 80°C to 90°C, and the heating temperature in the post-curing stage is 120°C to 150°C; the second foam layer is cured into a bottom layer with a plurality of microchannels formed inside, the bottom layer is adhered to the surface of the top layer, and the base fabric is adhered to the surface of the bottom layer; and the release paper peeling step: the release paper is peeled off, and the top layer, the bottom layer and the base fabric are cured and bonded to form a waterproof and breathable silicone leather.

According to the embodiments of the present invention, the steps of the method are not limited by number, as long as the top layer is prepared before the base layer; the base coat can also be prepared before the top coat, or the base coat can be prepared after the top coat is prepared.

According to the embodiment of the present invention, in the preparation step of the adhesive, the first foaming system is formed by thoroughly mixing at a speed of 2000 rpm to 4000 rpm for 15 to 20 minutes using a dual planetary mixer.

According to the present invention, in the preparation step of the primer, the foam structure mixture is formed by mixing the liquid silicone and the vinyl silicone oil using a dual planetary mixer for 15 to 20 minutes.

According to the embodiment of the present invention, in the preparation step of the primer, the second foaming system is formed by thoroughly mixing at a speed of 4000 rpm to 6000 rpm for 15 to 20 minutes using a dual planetary mixer.

According to the embodiments of the present invention, the total time for the curing process in the surface layer preparation step or the base layer preparation step can be from 10 minutes to 30 minutes.

In one embodiment, the heating time in the pre-curing stage is 10 to 15 minutes, and the heating time in the post-curing stage is 10 to 15 minutes.

In one embodiment, in the surface layer preparation step or the bottom layer preparation step S4, the heating temperature of the pre-curing stage can be 80°C, 85°C or 90°C; but not limited thereto, each of the above specific values can be used as an endpoint value of another range.

In one embodiment, in the surface layer preparation step or the bottom layer preparation step, the heating temperature of the post-curing stage can be 120°C, 130°C, 140°C or 150°C; but not limited thereto, each of the above specific values can be used as an endpoint value of another range.

In one embodiment, the volume ratio of the first foam in the adhesive preparation step to its raw materials (the sum of liquid silicone and talc) is approximately 1.2:1.

In one embodiment, the volume ratio of the second foam in the primer preparation step to its raw materials (the sum of liquid silicone, vinyl silicone oil and aluminum hydroxide) is approximately 1.2:1.

To facilitate understanding of the technical features, content, advantages, and effects of this invention, the following detailed description of the invention in conjunction with the accompanying drawings is provided. However, the drawings used are intended only for illustrative and explanatory purposes and may not represent the actual scale and precise configuration of the invention in practice. Therefore, the scale and configuration of the accompanying drawings should not be interpreted or used to limit the scope of the invention's claims in actual practice. This is stated above.

Waterproof and breathable silicone leather

As shown in Figures 1 to 5, the manufacturing process structure and method of the waterproof and breathable silicone leather of the present invention are provided.

As shown in Figure 5, the steps of the method for preparing the waterproof and breathable silicone leather of the present invention include a top adhesive preparation step S1, a base adhesive preparation step S2, a top layer preparation step S3 (see also Figure 1), a bottom layer preparation step S4 (see also Figures 2 and 3), and a release paper peeling step S5 (see also Figure 4). Thus, through the aforementioned steps, a waterproof and breathable silicone leather structure as shown in Figure 4 is obtained, which includes a top layer 20, a bottom layer 30, and a base fabric 40.

As shown in Figure 4, the surface layer 20 has a first surface 21 and a second surface 22 opposite to the first surface 21; the interior of the surface layer 20 is mechanically foamed to form an irregular microchannel 23, which is connected to the first surface 21 and the second surface 22 to form a waterproof and breathable pore 24. The bottom layer 30 has a third surface 31 and a fourth surface 32 opposite to the third surface 31. The interior of the bottom layer 30 is mechanically foamed to form irregularly shaped microchannels 33, which connect to the third surface 31 and the fourth surface 32 to form waterproof and breathable pores 34. The third surface 31 of the bottom layer 30 is bonded to the second surface 22 of the top layer 20. The waterproof and breathable pores 34 on the third surface 31 are connected to the waterproof and breathable pores 24 on the second surface 22. The microchannels 33 of the bottom layer 30 connect to the microchannels 23 of the top layer 20. The base fabric 40 is applied and bonded to the fourth surface 32 of the bottom layer 30 during the manufacturing process.

Implementation Examples 1 to 8 (E1 to E8):

The composition of Examples 1 to 8 is shown in Table 1 below; the manufacturing steps of Examples 1 to 8 are as follows: Adhesive preparation step S1: As described in Table 1 below, according to the proportions of each embodiment by weight, liquid silicone (China, Dongguan Wenyi, model: ADO-1) and talc powder (Xufeng, model: XFH-934071-Y6) are thoroughly stirred for 15 to 20 minutes at a speed of 2000 rpm to 4000 rpm to mechanically foam and form a first foam; color paste is added to the first foam and stirred for 10 to 15 minutes to ensure thorough mixing of the color paste with the first foam; then a hydrogen-containing crosslinking agent (0.75wt% hydrogen content, Kunshan Dawei, model: DW-300100) and a platinum catalyst ( _{H₂PtCl₆ )} are added. The concentration was 2000ppm (Kunshan Dawei, model: DW-2000SW). The mixture was then thoroughly mixed. Primer preparation step S2: As described in Table 1 below, by weight, according to the proportions of each embodiment, liquid silicone (China, Dongguan Wenyi, model: ADO-1) and vinyl silicone oil (China, Kunshan Dawei, model: DW-300550) were mixed using a double planetary mixer to form a foam structure mixture; then aluminum hydroxide (Al(OH) ₃ ) was added to the foam structure mixture. The particles (with a surface area particle size (D50) of 2.6µm to 3.5µm) were thoroughly stirred for 15 to 20 minutes using a dual planetary mixer at a speed of 4000 to 6000 rpm to mechanically foam and form a second foam. Then, a hydrogen-containing crosslinking agent (0.75wt% hydrogen content, Kunshan Dawei, model: DW-300100) and _a platinum catalyst ( _H2PtCl6 , concentration 2000ppm, Kunshan Dawei, model: DW-2000SW) were added and mixed evenly. Surface layer preparation step S3: The first foam body is coated on the surface of a release paper 10 with a thickness of 0.02 mm to 0.07 mm to form a first foam layer; the first foam layer and the release paper 10 are transferred to a 20-meter-long tunnel oven for baking and curing; the temperature is heated at 80°C to 90°C for 10 to 15 minutes in the first stage of curing and the temperature is heated at 120°C to 150°C for 10 to 15 minutes in the second stage of curing and the first foam layer is cured and formed into a surface layer 20 with a plurality of microchannels 23 formed inside (as shown in Figure 1); Substrate preparation step S4: The second foam is scraped onto the surface of the top layer 20 with a thickness of 0.07 mm to 0.15 mm to form a second foam layer (as shown in Figure 2). Immediately afterward, a base fabric 40 is covered onto the surface of the second foam layer (as shown in Figure 3). The second foam layer, the base fabric 40, the top layer 20, and the release paper 10 are then transferred to the tunnel oven for baking and curing. The curing process begins with heating at 80°C to 90°C for 10 to 15 minutes before curing, followed by heating at 120°C to 150°C for 10 to 15 minutes after curing. This process cures the second foam layer into a bottom layer 30 with a plurality of microchannels 33 inside. The bottom layer 30 is adhered to the surface of the top layer 20, and the base fabric 40 is adhered to the surface of the bottom layer 30 (as shown in Figure 3). Release paper peeling step S5: The release paper 10 is peeled off, and the top layer 20, the bottom layer 30, and the base fabric 40 are cured and bonded together to form a waterproof and breathable silicone leather (as shown in Figure 4).

Table 1: Structure Composition Implementation Examples E1 E2 E3 E4 E5 E6 E7 E8 Surface layer Liquid silicone 100 100 100 100 100 100 100 100 talcum powder 5 10 8 8 8 8 8 8 Pigment 2 2 2 2 2 2 2 2 Hydrogen-containing crosslinkers 4 4 2 6 4 4 4 4 Platinum catalyst 1.1 1.1 1.1 1.1 1 1.2 1.1 1.1 bottom layer Liquid silicone 100 100 100 100 100 100 100 100 Vinyl silicone oil 7 7 7 7 7 7 7 7 Aluminum hydroxide 90 90 90 90 90 90 80 100 Pigment 2 2 2 2 2 2 2 2 Hydrogen-containing crosslinkers 4 4 2 6 4 4 4 4 Platinum catalyst 1.1 1.1 1.1 1.1 1 1.2 1.1 1.1

Comparative Examples 1 to 8 (C1 to C8):

The composition of Comparative Examples 1 to 8 is shown in Table 1 below; the manufacturing steps of Comparative Examples 1 to 8 are the same as those of Examples 1 to 8.

Table 2: Structure Composition Comparison C1 C2 C3 C4 C5 C6 C7 C8 Surface layer Liquid silicone 100 100 100 100 100 100 100 100 talcum powder 4 11 8 8 8 8 8 8 Pigment 2 2 2 2 2 2 2 2 Hydrogen-containing crosslinkers 4 4 1 7 4 4 4 4 Platinum catalyst 1.1 1.1 1.1 1.1 0.9 1.3 1.1 1.1 bottom layer Liquid silicone 100 100 100 100 100 100 100 100 Vinyl silicone oil 7 7 7 7 7 7 7 7 Aluminum hydroxide 90 90 90 90 90 90 79 101 Pigment 2 2 2 2 2 2 2 2 Hydrogen-containing crosslinkers 4 4 1 7 4 4 4 4 Platinum catalyst 1.1 1.1 1.1 1.1 0.9 1.3 1.1 1.1

Performance Testing

Table 3 below provides the product feel, breathability, water resistance ratings, and tear strength test results for Examples 1 to 8 (E1 to E8) and Comparative Examples 1 to 8 (C1 to C8).

Table 3: Product Name feel breathability Waterproof Tear strength (KG) Implementation Examples E1 5 5 6 15 E2 5 6 6 14 E3 6 5 6 14 E4 5 5 6 17 E5 6 5 6 15 E6 5 5 6 14 E7 5 5 6 16 E8 5 6 6 14 Comparison C1 4 3 5 11 C2 4 4 5 11 C3 4 4 5 10 C4 3 4 5 13 C5 4 4 5 12 C6 3 4 5 10 C7 4 3 5 11 C8 4 4 5 10

Test Example 1: Product Feel

As shown in Table 3, the feel is subjectively determined according to the grades 1 to 6, where 1 indicates a very hard product, 2 indicates a hard product, 3 indicates a slightly hard product, 4 indicates a slightly soft product, 5 indicates a soft product, and 6 indicates a very soft product. N/M = cannot be measured.

As shown in Table 3, the silicone leather products of Examples E1 to E8 all have a soft or very soft feel. In contrast, referring to Tables 1 and 2, after one or two components exceed the composition ratio range defined in Examples E1 to E8, the products of Comparative Examples C1 to C8 all have a slightly firm or slightly soft feel. This shows that the composition ratio defined in Examples E1 to E8 can indeed bring a superior tactile experience to the products.

Test Example 2: Product Breathability

As shown in Figures 6 and 7, an air permeability testing device 50 is provided, which includes an air inlet bottle 51 and a permeable cylinder 54, both of which are cylindrical and have similar thickness and diameter. The bottom of the air inlet bottle 51 is sealed and connected to an air inlet pipe 511. The top of the air inlet bottle 51 is formed with a bottle mouth (which is covered by silicone leather A in Figures 6 and 7). The top and bottom ends of the permeable cylinder 54 are connected and formed as an upper opening 541 and a lower opening 542, respectively. A hook is provided on each of the opposite outer walls of the air inlet bottle 51. Part 52, the outer walls of the bottom end of the ventilated cylinder 54 are respectively provided with fastening clips 53 on both sides; as shown in Figures 6 and 7, the silicone leather A of Embodiments 1 to 8 (E1 to E8) and Comparative Examples 1 to 8 (C1 to C8) is clamped between the bottle mouth of the air inlet 51 and the lower opening 542 of the ventilated cylinder 54. After the fastening clips 53 are aligned with the hook part 52 and fastened, the silicone leather A is clamped and sealed between the bottle mouth of the air inlet 51 and the lower opening 542 of the ventilated cylinder 54. Therefore, in Experiment 2, water was added to the ventilated cylinder 54 and gas was introduced through the air inlet pipe 511. The condition of bubbles being generated on the surface of the silicone leather A (the surface in contact with water) was evaluated by visually observing the gas being introduced for 10 seconds.

As shown in Table 3, breathability is subjectively determined according to grades 1 to 6, where 1 indicates a product with no bubbles, 2 indicates a product with very few bubbles, 3 indicates a product with no bubbles on some parts of the surface, 4 indicates a product with bubbles on the surface, 5 indicates a product with many bubbles, and 6 indicates a product with a large number of bubbles. N/M = cannot be measured.

As shown in Table 3, the silicone leathers of Examples E1 to E8 all exhibited a high number or extremely high number of bubbles in the breathability test, indicating that the products of Examples E1 to E8 have excellent breathability. In contrast, referring to Tables 1 and 2, when one or two components exceed the composition ratio range specified in Examples E1 to E8, it can be seen that Comparative Examples C1 to C8 all exhibited a state of no bubbles on the surface or bubbles only on the surface in the breathability test. This shows that the breathability of the products of Comparative Examples C1 to C8 is quite limited and far inferior to that of Examples E1 to E8.

Test Example 3: Product Water Resistance

Using the same air permeability testing device 50 as in Figures 6 and 7, after introducing gas for 10 seconds in Test Example 2, the gas supply was stopped. The lower surface of the silicone leather A (the surface in contact with the gas) was visually inspected to determine whether water leakage occurred 10 seconds after the gas supply was stopped.

As shown in Table 3, air permeability is subjectively determined according to grades 1 to 6, where 1 indicates products with obvious water leakage, 2 indicates products with slight water leakage on the lower surface, 3 indicates products with obvious water seepage on the lower surface, 4 indicates products with slight water seepage on the lower surface, 5 indicates products with slight moisture in the air intake cylinder, and 6 indicates products with no moisture in the air intake cylinder. N/M = cannot be measured.

As shown in Table 3, the silicone leathers of Examples E1 to E8 all exhibited a state of complete dryness in the air intake during the waterproofing test, demonstrating that the products of Examples E1 to E8 have excellent waterproofing performance and can effectively prevent water or moisture penetration. In contrast, referring to Tables 1 and 2, when one or two components exceed the composition ratio range specified in Examples E1 to E8, it can be seen that Comparative Examples C1 to C8 all exhibited a state of slight moisture in the air intake during the waterproofing test. This indicates that the waterproofing performance of Comparative Examples C1 to C8 is poor and cannot achieve true waterproof and breathable performance.

Test Example 4: Product Tear Strength

This test example is based on the standard method ASTM D2262.

As shown in Table 3, the tear strength of the silicone leather products of Examples E1 to E8 ranges from 14 kg to 17 kg. In contrast, referring to Tables 1 and 2, when one or two components exceed the composition ratio range defined in Examples E1 to E8, the tear strength of the products of Comparative Examples C1 to C8 ranges from 10 kg to 13 kg, which is significantly lower than the tear strength performance of Examples E1 to E8. Therefore, it is evident that the composition ratios defined in the silicone leather of Examples E1 to E8 can indeed bring superior tear strength to the products.

The embodiments described above are merely for illustrating the technical ideas and features of this invention. Their purpose is to enable those skilled in this art to understand the content of this invention and implement it accordingly. They should not be used to limit the scope of the patent of this invention. All equivalent changes or modifications made in accordance with the spirit of this invention should still be covered within the scope of the patent of this invention.

10: Release paper 20: Top layer 21: First surface 22: Second surface 23: Microchannels 24: Waterproof and breathable pores 30: Bottom layer 31: Third surface 32: Fourth surface 33: Microchannels 34: Waterproof and breathable pores 40: Base fabric 50: Breathability testing device 51: Air inlet bottle 511: Air inlet pipe 52: Hook part 53: Fastening clip 54: Breathable cylinder 541: Top opening 542: Bottom opening A: Silicone leather S1: Topcoat preparation steps S2: Basecoat preparation steps S3: Top layer preparation steps S4: Base layer preparation steps S5: Release Paper Peeling Steps

Figure 1 is a schematic diagram of the surface layer of the organic silicone leather of the present invention molded on release paper. Figure 2 is a schematic diagram of the surface layer and base layer of the organic silicone leather of the present invention bonded on release paper. Figure 3 is a schematic diagram of the surface layer, base layer, and base fabric of the organic silicone leather of the present invention bonded on release paper. Figure 4 is a schematic diagram of the structure of the organic silicone leather of the present invention. Figure 5 is a flowchart of the manufacturing steps of the organic silicone leather of the present invention. Figure 6 is a structural diagram (I) of the experimental apparatus for Experimental Example 2 of the present invention. Figure 7 is a structural diagram (II) of the experimental apparatus for Experimental Example 2 of the present invention.

20: Surface Layer

21: First Surface

22: Second Surface

23: Miniature Channel

24: Waterproof and breathable pores

30: Bottom layer

31: Third Surface

32: Fourth Surface

33: Miniature Channel

34: Waterproof and breathable pores

40: Base

Claims (11)

A waterproof and breathable silicone leather includes: a top layer having a first surface and a second surface opposite to the first surface; the interior of the top layer is mechanically foamed to form irregular microchannels, the microchannels connecting to the first surface and the second surface to form waterproof and breathable pores; a bottom layer having a third surface and a fourth surface opposite to the third surface; the interior of the bottom layer is mechanically foamed to form another irregular microchannel, the other microchannel connecting to the third surface and the fourth surface to form another waterproof and breathable pore; the third surface of the bottom layer is bonded to the second surface of the top layer, the other waterproof and breathable pore on the third surface is conductive to the waterproof and breathable pore on the second surface, and the... The bottom layer has another microchannel that connects to the microchannel in the top layer; and a base fabric that covers and is bonded to the fourth surface of the bottom layer; wherein the pore size of the microchannel and the waterproof and breathable pore in the top layer is 0.2 μm to 5 μm; the pore size of the microchannel and the waterproof and breathable pore in the bottom layer is 0.2 μm to 5 μm; the thickness of the silicone leather is 0.08 mm to 0.15 mm; the thickness ratio of the top layer to the bottom layer is 2:7 to 7:15; and the composition of the top layer, by weight, includes: liquid silicone, 100 parts by weight; talc, 5 parts by weight to 10 parts by weight; hydrogen-containing crosslinker, 2 parts by weight to 6 parts by weight; and platinum catalyst, 1 part by weight to 1.2 parts by weight. The waterproof and breathable silicone leather as described in claim 1, wherein the base layer comprises, by weight,: 100 parts by weight of liquid silicone; 4 to 10 parts by weight of vinyl silicone oil; 80 to 100 parts by weight of aluminum hydroxide; 2 to 6 parts by weight of a hydrogen-containing crosslinker; and 1 to 1.2 parts by weight of a platinum catalyst. The waterproof and breathable silicone leather as described in claim 2, wherein the hydrogen content of the hydrogen-containing crosslinker in the top layer and the bottom layer is independently 0.5wt% to 1.0wt%. The waterproof and breathable silicone leather as described in claim 3, wherein the platinum catalyst in the top layer and the bottom layer is chloroplatinic acid ( _{H₂PtCl₆ )} at a concentration of 500ppm to 5000ppm, respectively. A method for preparing waterproof and breathable silicone leather includes the following steps: Top adhesive preparation step: 100 parts by weight of liquid silicone and 5 to 10 parts by weight of talc are mechanically foamed to form a first foam; then 0.2 to 0.6 parts by weight of a hydrogen-containing crosslinking agent and 0.1 to 0.12 parts by weight of a platinum catalyst are added and mixed evenly; Base adhesive preparation step: 100 parts by weight of liquid silicone and 4 to 10 parts by weight of vinyl silicone oil are mixed and stirred to form a foam structure mixture; then 80 to 100 parts by weight of aluminum hydroxide (Al(OH) ₃ ) are added to the foam structure mixture. The first foam is mechanically foamed to form a second foam; then 0.2 to 0.6 parts of a hydrogen-containing crosslinker and 0.1 to 0.12 parts of a platinum catalyst are added and mixed evenly; the surface layer preparation step: the first foam is coated onto the surface of a release paper with a thickness of 0.02 mm to 0.07 mm to form a first foam layer; the first foam layer and the release paper are then transferred to a tunnel oven for baking and curing. The curing process is defined as follows: the first half of the total curing time is the pre-curing stage, and the second half of the total curing time is the post-curing stage. The heating temperature in the pre-curing stage is 80°C to 90°C, and the heating temperature in the post-curing stage is 120°C to 150°C. The first foam layer is cured into a surface layer with a plurality of microchannels inside. The bottom layer preparation step is as follows: the second foam is prepared at 0. A second foam layer is formed by applying a layer of material with a thickness of 0.07mm to 0.15mm to the surface of the top layer. Immediately afterward, a base fabric is applied over the second foam layer. The second foam layer, the base fabric, the top layer, and the release paper are then transferred to a tunnel oven for curing and molding. The first half of the total curing time is defined as the pre-curing stage, and the second half as the post-curing stage. The heating temperature of the front section is 80°C to 90°C, and the heating temperature of the later section of curing is 120°C to 150°C; the second foam layer is cured and molded into a bottom layer with a plurality of microchannels inside, the bottom layer is adhered to the surface of the top layer, and the base fabric is adhered to the surface of the bottom layer; release paper peeling step: the release paper is peeled off, and the top layer, the bottom layer and the base fabric are cured and bonded to form a waterproof and breathable silicone leather. The method for preparing waterproof and breathable silicone leather as described in claim 5, wherein in the preparation steps of the top adhesive and the preparation steps of the base adhesive, the hydrogen content of the hydrogen-containing crosslinker is 0.5wt% to 1.0wt%. The method for preparing waterproof and breathable silicone leather as described in claim 6, wherein in the preparation steps of the top adhesive and the preparation steps of the base adhesive, the platinum catalyst is chloroplatinic acid with a concentration of 500 ppm to 5000 ppm. The method for preparing waterproof and breathable silicone leather as described in claim 7, wherein the average particle size (D50) of the talc powder is 2.6 micrometers (µm) to 3.5µm. The method for preparing waterproof and breathable silicone leather as described in claim 8, wherein the average particle size (D50) of the aluminum hydroxide is 2.6µm to 3.5µm. The method for preparing waterproof and breathable silicone leather as described in claim 9, wherein the thickness of the silicone leather is 0.09 mm to 0.22 mm. The method for preparing waterproof and breathable silicone leather as described in claim 10, wherein the thickness ratio of the top layer to the bottom layer is 2:7 to 7:15.