High-elasticity braid silicone rubber for bonding and coating as well as preparation method and application of high-elasticity braid silicone rubber

Abstract

The invention relates to the technical field of silicone rubber materials, and discloses high-elasticity braid silicone rubber for bonding and coating as well as a preparation method and application of the high-elasticity braid silicone rubber. The high-elasticity ribbon silicone rubber for bonding and coating is prepared from the following raw material components: vinyl silicone oil, alpha, omega-dihydroxy polydimethylsiloxane, hydrogen-containing silicone oil, methyl triethoxysilane, nano calcium carbonate, gamma-glycidyl ether oxypropyl trimethoxysilane, a platinum catalyst, auxiliary filler, an anti-yellowing agent and a toughening agent, wherein the vinyl silicone oil, the alpha, omega-dihydroxy polydimethylsiloxane, the hydrogen-containing silicone oil, the methyl triethoxysilane, the nano calcium carbonate, the gamma-glycidyl ether oxypropyl trimethoxysilane, the platinum catalyst, the auxiliary filler, the anti-yellowing agent and the toughening agent are used as raw materials; wherein the particle size of the nano calcium carbonate is 50-100 nm, and the nano calcium carbonate is obtained through stearic acid surface modification treatment. The preparation method is simple and efficient, the prepared high-elasticity woven tape silicone rubber for bonding and coating has excellent elasticity, bonding strength and weather resistance, the tensile strength of the high-elasticity woven tape silicone rubber can reach 6.2 MPa to the maximum, the elongation at break is larger than or equal to 640%, and the tensile strength retention rate after thermal aging is larger than or equal to 95%.

Description

Technical Field

[0001] This application relates to the field of silicone rubber materials technology, and in particular to a high-elasticity adhesive coating silicone rubber for webbing, its preparation method and application. Background Technology

[0002] Webbing, as a commonly used decorative and functional component, is widely used in products such as bags, clothing, and sporting goods. In the luxury bag sector, the appearance, durability, and functionality of webbing directly affect the product's quality and added value. To improve the performance of webbing, it is usually necessary to perform bonding or coating treatments. Silicone rubber, due to its excellent elasticity, resistance to high and low temperatures, and chemical stability, has become one of the commonly used materials for bonding and coating webbing. With the continuous development of related industries, the performance requirements for silicone rubber used in webbing bonding and coating are also becoming increasingly stringent. Improving its performance is of great significance for promoting the quality upgrade of high-end webbing and related products.

[0003] In existing technologies, ordinary silicone rubber is typically used to solve the bonding and coating problems of webbing. Ordinary silicone rubber has some applications in webbing bonding and coating, mainly utilizing its elasticity, resistance to high and low temperatures, and chemical stability to meet basic requirements. Some ordinary silicone rubbers have common additives added to improve their performance, such as adding antioxidants to enhance their antioxidant capacity and using crosslinking agents to promote the crosslinking reaction. However, these methods are mostly based on traditional formulations and processes, lacking targeted optimization for the specific performance requirements of webbing.

[0004] The existing ordinary silicone rubber used for webbing bonding coating has the problem of insufficient bonding strength. Its interface compatibility with high-elastic fabric webbing is poor, and the bonding firmness is not strong enough. During long-term use or frequent bending and stretching, the webbing is prone to falling off and curling, which cannot meet the usage requirements of high-elastic fabric webbing and high-end scenarios such as luxury bags. Summary of the Invention

[0005] To at least overcome one of the problems existing in the prior art, one objective of this invention is to provide a high-elasticity adhesive coating silicone rubber for webbing. This high-elasticity adhesive coating silicone rubber uses vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, and γ-glycidyl etheroxypropyltrimethoxysilane as raw materials. In particular, the limitation of the composition and ratio of each raw material ensures that the high-elasticity adhesive coating silicone rubber for webbing possesses strong adhesion, high elasticity, and excellent weather resistance, meeting the usage requirements of high-elasticity webbing and luxury bags, among other high-end applications. A second objective of this invention is to provide a method for preparing the aforementioned high-elasticity adhesive coating silicone rubber for webbing. A third objective of this application is to provide applications of the aforementioned high-elasticity adhesive coating silicone rubber for webbing.

[0006] Therefore, the present invention adopts the following technical solution: The first aspect of the present invention provides a high-elasticity adhesive coating silicone rubber for webbing, the raw material components of which include: vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, auxiliary filler, anti-yellowing agent, and toughening agent; wherein the nano-calcium carbonate has a particle size of 50~100nm and is obtained by surface modification treatment with stearic acid.

[0007] This application's high-elasticity adhesive coating silicone tape uses vinyl silicone oil and α,ω-dihydroxypolydimethylsiloxane as the base polymer system, constructing a three-dimensional network structure through the synergistic effects of addition and condensation reactions. Vinyl silicone oil, as the main polymer, undergoes rapid hydrosilylation crosslinking between its side chains or terminal vinyl groups and the Si-H bonds of hydrogen-containing silicone oil under the action of a platinum catalyst, forming a highly elastic main network framework that provides excellent initial elasticity and curing efficiency. A small amount of added α,ω-dihydroxypolydimethylsiloxane plays an auxiliary reinforcing role; its terminal hydroxyl groups can undergo condensation crosslinking with hydrogen-containing silicone oil and methyltriethoxysilane, further densifying the network structure and improving the system's cohesive strength and heat resistance. These two crosslinking mechanisms complement each other, which is beneficial for further optimizing the elasticity and strength of the high-elasticity adhesive coating silicone tape. In this dual-curing system, under the action of a platinum catalyst, the Si-H bonds of the hydrogen-containing silicone oil can react with the epoxy groups and other groups of γ-glycidoxypropyltrimethoxysilane. Simultaneously, in application, the epoxy and methoxy groups of γ-glycidoxypropyltrimethoxysilane can form chemical bonds or strong hydrogen bonds with the amino, carboxyl, or hydroxyl groups on the surface of nylon, polyester, and other webbing materials, significantly improving the direct chemical adhesion of silicone rubber to the webbing and solving the problem of easy peeling of the coating layer. Nano-calcium carbonate with a particle size of 50-100 nm, obtained through stearic acid surface modification, increases the contact area between it and α,ω-dihydroxypolydimethylsiloxane. The surface of the nano-calcium carbonate changes from hydrophilic to hydrophobic, greatly improving its compatibility with the silicone rubber matrix. This is beneficial for improving the material's dispersion uniformity, thereby enhancing the material's mechanical properties and avoiding coating appearance defects caused by particle agglomeration. The auxiliary fillers further modulate the overall rheology and reinforcement; the anti-yellowing agent ensures long-term weather resistance; and the toughening agent helps improve the toughness of the material. Through the synergistic effect between the components, the high-elasticity adhesive coating silicone rubber of this application possesses excellent elasticity, adhesive strength, mechanical properties, and weather resistance.

[0008] Preferably, the nano-calcium carbonate has a particle size of 50-100 nm and is obtained through surface modification treatment with stearic acid. More preferably, the nano-calcium carbonate has a particle size of 70-100 nm and is obtained through surface modification treatment with stearic acid. Even more preferably, the nano-calcium carbonate has a particle size of 80-100 nm and is obtained through surface modification treatment with stearic acid.

[0009] Preferably, the method for preparing the stearic acid-modified nano-calcium carbonate includes the following steps: (1) Pretreatment: Dry the nano-calcium carbonate powder with a particle size of 50~100nm at 100~120℃ for 2~4h and set aside; (2) Dispersion: Add 100 parts by weight of dried nano-calcium carbonate powder to 300-500 parts by weight of anhydrous ethanol or acetone, and ultrasonically disperse for 30-60 minutes to form a uniform suspension. (3) Modification reaction: Dissolve 2-5 parts by weight of stearic acid in anhydrous ethanol at a weight ratio of 1:1, and add it to the suspension in step S2. Heat to 70-85°C and stir continuously for 2-4 hours. (4) Post-treatment: After filtration and washing with anhydrous ethanol, the nano-calcium carbonate with stearic acid surface modification is obtained by drying in a vacuum drying oven at 80~100℃ for 4~8h, grinding, and passing through a standard sieve of 200~300 mesh.

[0010] Preferably, the vinyl silicone oil has a viscosity of 6000~20000 mPa·s at 25°C and a vinyl content of 0.1~0.5 wt%. More preferably, the vinyl silicone oil has a viscosity of 8000~20000 mPa·s at 25°C and a vinyl content of 0.3~0.5 wt%.

[0011] Preferably, the α,ω-dihydroxypolydimethylsiloxane has a number-average molecular weight of 50,000 to 100,000 and a viscosity of 5,000 to 15,000 mPa·s at 25°C. More preferably, the α,ω-dihydroxypolydimethylsiloxane has a number-average molecular weight of 60,000 to 100,000 and a viscosity of 8,000 to 15,000 mPa·s at 25°C. Even more preferably, the α,ω-dihydroxypolydimethylsiloxane has a number-average molecular weight of 80,000 to 100,000 and a viscosity of 9,000 to 15,000 mPa·s at 25°C.

[0012] If the number-average molecular weight of α,ω-dihydroxypolydimethylsiloxane is too low, the viscosity will be too low, resulting in insufficient strength. This can easily cause excessive penetration of silicone rubber into the webbing during coating, affecting the appearance and feel. If the number-average molecular weight of α,ω-dihydroxypolydimethylsiloxane is too high, the viscosity will be too high, leading to poor overall flowability and making it difficult to achieve uniform and smooth thin-layer coating during use. The number-average molecular weight and viscosity of α,ω-dihydroxypolydimethylsiloxane are controlled within the range of this application. Its molecular chain length is moderate, and after reacting with the crosslinking agent hydrogen-containing silicone oil and methyltriethoxysilane, it can form a network structure with sufficient crosslinking points to ensure a certain strength and sufficiently long flexible segments to provide high elasticity.

[0013] Preferably, the hydrogen-containing silicone oil has a hydrogen content of 0.1~0.3wt% and a number-average molecular weight of 1000~3000. More preferably, the hydrogen-containing silicone oil has a hydrogen content of 0.15~0.3wt% and a number-average molecular weight of 2000~3000. Even more preferably, the hydrogen-containing silicone oil has a hydrogen content of 0.2~0.3wt% and a number-average molecular weight of 2500~3000.

[0014] Controlling the hydrogen content of the hydrogen-containing silicone oil to 0.1~0.3wt% is beneficial for the condensation reaction between the Si-H bonds of the hydrogen-containing silicone oil and the vinyl groups of α,ω-dihydroxypolydimethylsiloxane, achieving sufficient crosslinking. If the hydrogen content is too low, the resulting three-dimensional network structure will be loose due to insufficient crosslinking sites, leading to poor tensile strength of the silicone rubber. If the hydrogen content is too high, the crosslinking density will be too large, easily causing a decrease in the elongation at break of the silicone rubber, making the material brittle during later use and unable to meet the high elasticity requirements of webbing. Within this hydrogen content range, a crosslinking network of moderate density is formed, thus balancing the overall strength and elasticity. If the number-average molecular weight of the hydrogen-containing silicone oil is too low, its volatility is high, it is easily lost during processing, and crosslinking is insufficient. If the number-average molecular weight is too high, the dispersibility of the hydrogen-containing silicone oil in the matrix deteriorates, the crosslinking reaction is uneven, and there are performance differences within the material. Maintaining the number-average molecular weight range of the hydrogen-containing silicone oil in this application ensures uniform dispersion and low volatility of the hydrogen-containing silicone oil, achieving efficient and uniform crosslinking and guaranteeing the overall consistency of the silicone rubber's performance.

[0015] Preferably, the platinum catalyst is a chloroplatinic acid-vinylsiloxane complex, and the platinum content in the platinum catalyst is 500-1000 ppm by mass. More preferably, the platinum catalyst is a chloroplatinic acid-vinylsiloxane complex, and the platinum content in the platinum catalyst is 650-1000 ppm by mass.

[0016] Preferably, the auxiliary filler is a mixture of fumed silica and precipitated silica in a weight ratio of (1~3):(2~5). More preferably, the auxiliary filler is a mixture of fumed silica and precipitated silica in a weight ratio of (1.4~3):(2~5). Even more preferably, the auxiliary filler is a mixture of fumed silica and precipitated silica in a weight ratio of (1.5~3):(3.5~5).

[0017] Preferably, the anti-yellowing agent is a compound of hindered phenolic antioxidant and ultraviolet absorber in a weight ratio of (1~2.5):1. More preferably, the anti-yellowing agent is a compound of hindered phenolic antioxidant and ultraviolet absorber in a weight ratio of (1.2~2.5):1. Even more preferably, the anti-yellowing agent is a compound of hindered phenolic antioxidant and ultraviolet absorber in a weight ratio of (1.6~2.5):1.

[0018] Preferably, the hindered phenolic antioxidant is selected from at least one of antioxidant 330, antioxidant 1010, antioxidant 1076, and antioxidant 3114. More preferably, the hindered phenolic antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, and antioxidant 3114. Even more preferably, the hindered phenolic antioxidant is selected from at least one of antioxidant 1010 and antioxidant 3114.

[0019] Preferably, the ultraviolet absorber is selected from at least one of UV-327, UV-329, and UV-571. More preferably, the ultraviolet absorber is selected from at least one of UV-327 and UV-329.

[0020] Preferably, the toughening agent is hydroxyl-terminated polybutadiene or a polyether polyol, wherein the polyether polyol is selected from at least one of polypropylene glycol, polytetrahydrofuran glycol, and polymethyltetrahydrofuran glycol. More preferably, the polyether polyol is selected from at least one of polypropylene glycol and polytetrahydrofuran glycol.

[0021] The platinum catalyst is a chloroplatinic acid-vinylsiloxane complex with a platinum content of 500-1000 ppm. This limited range ensures sufficient catalytic activity, enabling the hydrosilylation reaction to proceed rapidly at lower temperatures and improving production efficiency. Simultaneously, the complex exhibits good stability, reducing the risk of early sulfidation before construction.

[0022] Among auxiliary fillers, fumed silica has a good reinforcing effect and can significantly improve the tensile strength, tear strength and modulus of silicone rubber, but the cost is too high and a high addition amount may affect the flowability; while precipitated silica has a less effective reinforcing effect than fumed silica, but its cost is lower and it helps to improve the overall leveling. By controlling the weight ratio of the two to (1~3):(2~5), a balance between performance and cost is achieved, so that silicone rubber can maintain good coating workability while obtaining good mechanical properties and reducing costs.

[0023] In anti-yellowing agents, hindered phenolic antioxidants effectively capture free radicals generated by materials under heat and oxygen, interrupting chain oxidation reactions and preventing yellowing and performance degradation caused by thermo-oxidative aging. Ultraviolet absorbers strongly absorb ultraviolet light in the 290-400nm range, converting it into heat energy, thus preventing yellowing, chalking, and cracking caused by photoaging. Combining these two agents in a weight ratio of (1-2.5):1 achieves multi-faceted protection against multiple aging factors such as heat, oxygen, and ultraviolet light. This allows silicone-coated webbing to effectively inhibit yellowing and maintain stable appearance and physical properties during long-term use in harsh environments such as outdoor sunlight and high temperatures.

[0024] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, and nano-calcium carbonate is (50~70):(5~10):(8~15):(2~6):(10~20).

[0025] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, and γ-glycidyl etheroxypropyltrimethoxysilane is (50~70):(5~10):(8~15):(2~6):(10~20):(2~6).

[0026] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, and platinum catalyst is (50~70):(5~10):(8~15):(2~6):(10~20):(2~6):(0.01~0.05).

[0027] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, and auxiliary filler is (50~70):(5~10):(8~15):(2~6):(10~20):(2~6):(0.01~0.05):(1~3).

[0028] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, auxiliary filler, and anti-yellowing agent is (50~70):(5~10):(8~15):(2~6):(10~20):(2~6):(0.01~0.05):(1~3):(0.8~2).

[0029] Preferably, in the raw materials of the high-elasticity adhesive coating tape silicone rubber, the weight ratio of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, auxiliary filler, anti-yellowing agent and toughening agent is (50~70):(5~10):(8~15):(2~6):(10~20):(0.01~0.05):(1~3):(0.8~2):(2~5).

[0030] In the high-elasticity adhesive coating silicone rubber for webbing of this application, by controlling the reasonable proportion of raw material components, 50-70 parts by weight of vinyl silicone oil and 5-10 parts by weight of α,ω-dihydroxypolydimethylsiloxane are used as the matrix to provide sufficient elasticity and processing basis for the silicone rubber; 8-15 parts by weight of hydrogen-containing silicone oil is used as the main crosslinking agent, and 2-6 parts by weight of methyltriethoxysilane is used as the auxiliary crosslinking agent. The amount matched with the matrix is ​​conducive to promoting the full progress of the crosslinking reaction and ultimately forming a crosslinking system with a moderate crosslinking density; 2-6 parts by weight of γ-glycidoxypropyltrimethoxysilane helps to effectively bond with the webbing fibers during use. This formula combines several key elements: insufficient dosage leading to inadequate adhesion, and excessive dosage leading to decreased elasticity; 10-20 parts by weight of nano-calcium carbonate provides reinforcement while avoiding excessive filling that could reduce elasticity; platinum catalyst ensures catalytic efficiency while controlling costs; auxiliary fillers help achieve a balance between reinforcement and processability; anti-yellowing agent effectively prevents yellowing while avoiding compatibility issues caused by excessive dosage; and toughening agent optimizes the toughness of silicone rubber without affecting strength. This formula maximizes the overall performance of the material, synergistically achieving a balance between strong adhesion, high elasticity, weather resistance, and processability in high-elasticity adhesive coating silicone tape.

[0031] A second aspect of the present invention provides a method for preparing the high-elasticity adhesive coating silicone rubber for webbing according to the first aspect of the present invention, comprising the following steps: S1. Mix vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, nano-calcium carbonate, auxiliary fillers and toughening agents, and heat to premix to obtain a premix; S2. Cool the premixed material, add hydrogen-containing silicone oil, methyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane, and continue mixing. S3. Add anti-yellowing agent and platinum catalyst, and after stirring, discharging and degassing, obtain the high-elasticity adhesive coating tape silicone rubber.

[0032] Preferably, in step S1, the heating temperature is 80~100℃, the premixing speed is 30~50 r / min, and the premixing time is 30~60 min. More preferably, in step S1, the heating temperature is 90~100℃, the premixing speed is 35~50 r / min, and the premixing time is 40~60 min. Even more preferably, in step S1, the heating temperature is 90~100℃, the premixing speed is 40~50 r / min, and the premixing time is 45~60 min.

[0033] Preferably, in step S2, the temperature is lowered to 40-60°C, and the mixing time is 20-40 minutes. More preferably, in step S2, the temperature is lowered to 45-60°C, and the mixing time is 25-40 minutes. Even more preferably, in step S2, the temperature is lowered to 50-60°C, and the mixing time is 30-40 minutes.

[0034] Preferably, in step S3, the stirring is carried out under nitrogen protection, the stirring temperature is 40-50°C, the stirring speed is 20-30 r / min, the stirring time is 15-25 min, and the degassing time is 10-20 min. More preferably, in step S3, the stirring is carried out under nitrogen protection, the stirring temperature is 45-50°C, the stirring speed is 25-30 r / min, the stirring time is 15-25 min, and the degassing time is 10-20 min.

[0035] In the above technical solution, the high performance and high consistency of silicone rubber are ultimately ensured through a phased process of premixing, cooling mixing, stirring and degassing under nitrogen protection, combined with the optimization of process parameters. Specifically, step S1 involves thorough premixing of vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, nano-calcium carbonate, auxiliary fillers, and toughening agents at a temperature of 80-100℃ and a rotation speed of 30-50 r / min, laying the foundation for uniform dispersion and interfacial wetting of each component. Subsequently, in step S2, after cooling, the crosslinking agent hydrogen-containing silicone oil and methyltriethoxysilane, and the adhesion promoter γ-glycidyl etheroxypropyltrimethoxysilane are added, effectively preventing the platinum catalyst from prematurely contacting the hydrogen-containing silicone oil and causing localized pre-crosslinking, thus ensuring good stability of the final silicone rubber. Finally, in step S3, under nitrogen protection and a mild temperature, an anti-yellowing agent and platinum catalyst are added, followed by stirring and degassing, preventing catalyst deactivation due to oxidation or high temperature and completely eliminating air bubbles within the rubber. Through synergistic optimization of each step, the components are uniformly mixed, resulting in a high-elasticity adhesive coating silicone rubber tape that combines high elasticity, high adhesive strength, and excellent weather resistance.

[0036] The third aspect of this application provides the application of a high-elasticity adhesive coating silicone rubber for webbing in the coating of webbing surfaces. The high-elasticity adhesive coating silicone rubber for webbing is the aforementioned high-elasticity adhesive coating silicone rubber for webbing, or is prepared by the aforementioned preparation method.

[0037] Preferably, the webbing is selected from nylon, polyester, cotton, or blends thereof. More preferably, the webbing is nylon webbing or polyester webbing.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects: 1) The raw material components of the high-elasticity adhesive coating silicone rubber for webbing in this application include vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, auxiliary filler, anti-yellowing agent, and toughening agent; wherein, the nano-calcium carbonate has a particle size of 50~100nm and is obtained by surface modification treatment with stearic acid. Through the reasonable proportion of each raw material component, the prepared high-elasticity adhesive coating silicone rubber for webbing has excellent elasticity, adhesive strength, and weather resistance, with a maximum tensile strength of 6.2MPa, an elongation at break ≥640%, and a tensile strength retention rate ≥95% after heat aging.

[0039] 2) In the preparation method of the high-elasticity adhesive coating silicone rubber for webbing in this application, the high-elasticity adhesive coating silicone rubber for webbing is obtained by pre-mixing, cooling mixing, stirring under nitrogen protection, and degassing. This preparation method is simple, requires no complex equipment, is suitable for large-scale production, and helps to form a uniform and stable high-elasticity adhesive coating silicone rubber for webbing. Detailed Implementation

[0040] The present invention will be further described in detail below through specific embodiments, comparative examples and tables, but is not limited to all the discussions and data.

[0041] Vinyl silicone oil was purchased from Xin'an Chemical Group Co., Ltd., model XHG-206-10000, with a viscosity of 9000~13000 mPa·s at 25℃ and a vinyl content of 0.109~0.182 wt%; α,ω-dihydroxypolydimethylsiloxane was purchased from Hubei Jiyesheng Chemical Co., Ltd., with a number average molecular weight of 70000 and a viscosity of 8000±1000 mPa·s at 25℃; hydrogen-containing silicone oil was purchased from Zhejiang Hengyecheng Organosilicon Co., Ltd., with a hydrogen content of 0.12~0.16 wt% and a number average molecular weight of 1500±1000; nano-calcium carbonate powder was purchased from Shanghai Yuanjiang Chemical Co., Ltd., with an average particle size of 60~80 nm; chloroplatinic acid-vinylsiloxane complex was purchased from Zhejiang Xin'an Chemical Group Co., Ltd., with a platinum content of 800 ppm; fumed silica was purchased from Guangzhou Jibisheng Technology Industry Co., Ltd., hydrophilic type, with a specific surface area of ​​150~200 nm. m2 / g; Precipitated silica was purchased from Yong'an Fengyuan Chemical Co., Ltd., rubber grade, with a specific surface area of ​​160~190m2 / g; Polypropylene glycol was purchased from Shanghai Gaoqiao Petrochemical Co., Ltd., with a number average molecular weight of 1000±50 and a viscosity of 180~220mPa·s at 25℃.

[0042] Preparation Example 1: Stearic Acid Surface-Modified Nano-Calcium Carbonate The preparation method of stearic acid-modified nano-calcium carbonate includes the following steps: (1) Pretreatment: Dry the nano-calcium carbonate powder with a particle size of 60~80nm at 110℃ for 3h and set aside; (2) Dispersion: Add 100g of dried nano-calcium carbonate powder to 400g of anhydrous ethanol or acetone and ultrasonically disperse for 40min to form a uniform suspension. (3) Modification reaction: Dissolve 5g of stearic acid in anhydrous ethanol at a weight ratio of 1:1 and add it to the suspension in step S2. Heat to 80°C and stir continuously for 3 hours. (4) Post-treatment: After filtration and washing with anhydrous ethanol, the nano-calcium carbonate was dried in a vacuum drying oven at 90°C for 6 hours, ground, and passed through a 300-mesh standard sieve to obtain nano-calcium carbonate modified with stearic acid.

[0043] It is particularly important to emphasize that, unless otherwise specified, the raw materials, reagents or devices used in this invention can be obtained from conventional commercial sources.

[0044] Examples of silicone rubber for high-elasticity adhesive coating of webbing: A high-elasticity adhesive coating silicone rubber for webbing is prepared by the following steps: S1. Add 50-70g vinyl silicone oil, 5-10g α,ω-dihydroxypolydimethylsiloxane, 10-20g nano calcium carbonate, 1-3g auxiliary filler and 2-5g toughening agent to a mixer, heat to 80-100℃, set the speed to 30-50r / min, and premix for 30-60min to obtain a premix; S2. Cool the premix to 40~60℃, add 8~15g of hydrogen-containing silicone oil, 2~6g of methyltriethoxysilane, and 2~6g of γ-glycidyl etheroxypropyltrimethoxysilane, and continue to mix for 20~40min. S3. Add 0.8~2g of anti-yellowing agent and 0.01~0.05g of platinum catalyst, and stir for 15~25min at 40~50℃ and 20~30r / min under nitrogen protection. Discharge the material and transfer it to a vacuum degassing device for degassing for 10~20min to obtain the high-elasticity adhesive coating tape silicone rubber.

[0045] Regarding step S1, in some specific embodiments, the vinyl silicone oil has a viscosity of 6000 mPa·s, 10000 mPa·s, 15000 mPa·s, 18000 mPa·s, or 20000 mPa·s at 25°C, and the vinyl content can be 0.1 wt%, 0.2 wt%, 0.4 wt%, or 0.5 wt%. The number-average molecular weight of α,ω-dihydroxypolydimethylsiloxane can be 50000, 60000, 80000, or 100000, and its viscosity at 25°C can be 5000 mPa·s, 6500 mPa·s, 8000 mPa·s, 12000 mPa·s, or 15000 mPa·s. The particle size of the nano-calcium carbonate can be 50 nm, 60 nm, 80 nm, 90 nm, or 100 nm, and it is obtained through stearic acid surface modification treatment. The auxiliary filler can be a mixture of fumed silica and precipitated silica in a weight ratio of 3:2, 3:4, 1:2, or 2:5. The toughening agent can be hydroxyl-terminated polybutadiene or polyether polyol, and the polyether polyol can be selected from at least one of polypropylene glycol, polytetrahydrofuran glycol, and polymethyltetrahydrofuran glycol. The amount of vinyl silicone oil can be 50g, 55g, 60g or 70g; the amount of α,ω-dihydroxypolydimethylsiloxane can be 5g, 8g, 9g or 10g; the amount of nano-calcium carbonate can be 10g, 12g, 15g or 20g; the amount of auxiliary filler can be 1g, 2g, 2.5g or 3g; the amount of toughening agent can be 2g, 3g, 4g or 5g; the internal mixer is heated to 80℃, 90℃ or 100℃; the rotation speed can be set to 30r / min, 35r / min, 45r / min or 50r / min; and the premixing time can be 30min, 40min or 60min.

[0046] Regarding step S2, in some specific embodiments, the hydrogen content of the hydrogen-containing silicone oil can be 0.1wt%, 0.2wt%, or 0.3wt%, and the number average molecular weight can be 1000, 1800, 2500, or 3000. The premix can be cooled to 40℃, 50℃, or 60℃, and the amount of added hydrogen-containing silicone oil can be 8g, 10g, 12g, or 15g, the amount of methyltriethoxysilane can be 2g, 5g, or 6g, the amount of γ-glycidyl etheroxypropyltrimethoxysilane can be 2g, 4g, 5g, or 6g, and the mixing time can be 20min, 30min, 35min, or 40min.

[0047] Regarding step S3, in some specific embodiments, the anti-yellowing agent can be a mixture of hindered phenolic antioxidant and ultraviolet absorber in a weight ratio of 1:1, 1.2:1, 2:1, or 2.5:1. The hindered phenolic antioxidant can be selected from at least one of antioxidant 330, antioxidant 1010, antioxidant 1076, and antioxidant 3114, and the ultraviolet absorber can be selected from at least one of UV-327, UV-329, and UV-571. The platinum catalyst is a chloroplatinic acid-vinylsiloxane complex, wherein the platinum content is 500 ppm, 600 ppm, 700 ppm, or 1000 ppm. The dosage of the anti-yellowing agent can be 0.8g, 1g, 1.5g or 2g, and the dosage of the platinum catalyst can be 0.01g, 0.03g, 0.04g or 0.05g. Under nitrogen protection, the mixture is stirred for 15min, 20min or 25min at a temperature of 40℃, 45℃ or 50℃ and a speed of 20r / min, 25r / min or 30r / min. The mixture is then discharged and transferred to a vacuum degassing device for degassing for 10min, 15min or 20min. Example 1

[0048] A high-elasticity adhesive coating silicone rubber for webbing is prepared by the following steps: S1. Add 60g of vinyl silicone oil, 5g of α,ω-dihydroxypolydimethylsiloxane, 15g of nano-calcium carbonate modified with stearic acid as prepared in Example 1, 2g of auxiliary filler composed of fumed silica and precipitated silica in a weight ratio of 2:3, and 3g of polyoxypropylene glycol to a mixer, heat to 90°C, set the speed to 40r / min, and premix for 40min to obtain a premix. S2. Cool the premix to 50°C, add 10g of hydrogen-containing silicone oil, 4g of methyltriethoxysilane, and 4g of γ-glycidoxypropyltrimethoxysilane, and continue mixing for 30 minutes. S3. Add 1.5g of antioxidant 3114 and UV-327 compounded in a weight ratio of 2:1, and 0.03g of chloroplatinic acid-vinylsiloxane complex with a platinum content of 800ppm. Stir for 20min at 50℃ and 25r / min under nitrogen protection. Discharge the material and transfer it to a vacuum degassing device for degassing for 20min to obtain the high-elasticity adhesive coating tape silicone rubber. Example 2

[0049] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as in Example 1, except that the amount of α,ω-dihydroxypolydimethylsiloxane in Example 2 is changed to 8g. Example 3

[0050] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as in Example 1, except that the amount of α,ω-dihydroxypolydimethylsiloxane in Example 3 is changed to 10g. Example 4

[0051] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as that in Example 1, except that the amount of stearic acid-modified nano-calcium carbonate used in Example 1 is changed to 10g in Example 4. Example 5

[0052] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as that in Example 1, except that the amount of nano-calcium carbonate prepared by stearic acid surface modification in Example 1 is changed to 18g in Example 5. Example 6

[0053] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as in Example 1, except that the amount of auxiliary filler in Example 6 is changed to 1g. Example 7

[0054] The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as in Example 1, except that the amount of auxiliary filler in Example 7 is changed to 3g.

[0055] Comparative Example 1: The preparation method of a high-elasticity adhesive coating silicone rubber tape is the same as in Example 1, except that the amount of α,ω-dihydroxypolydimethylsiloxane in Comparative Example 1 is changed to 15g.

[0056] Comparative Example 2: The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as that in Example 1, except that the amount of stearic acid-modified nano-calcium carbonate in Comparative Example 2 is changed to 25g.

[0057] Comparative Example 3: The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as that in Example 1, except that the nano-calcium carbonate prepared in Example 1 by stearic acid surface modification in Comparative Example 3 is replaced with unmodified nano-calcium carbonate in equal amounts.

[0058] Comparative Example 4: The preparation method of a high-elasticity adhesive coating tape silicone rubber is the same as in Example 1, except that the amount of auxiliary filler in Comparative Example 4 is changed to 3.5g.

[0059] Application Example 1: The application of a high-elasticity adhesive coating silicone rubber for webbing in the coating of nylon webbing: using a precision coating machine, the high-elasticity adhesive coating silicone rubber for webbing of Example 1 was uniformly coated on the surface of a standard nylon webbing with a gap of 0.35 mm. After curing at 120°C for 30 min, the dry film thickness of the silicone rubber coating was measured to be 0.30 ± 0.03 mm.

[0060] Application Example 2: The application of a high-elasticity adhesive coating silicone rubber for webbing in coating the surface of nylon webbing is the same as in Application Example 1, except that the standard nylon webbing is replaced with polyester webbing.

[0061] Application Example 3: The application of a high-elasticity adhesive coating silicone rubber for webbing in coating the surface of nylon webbing is the same as in Application Example 1, except that the standard nylon webbing is replaced with 100% cotton webbing.

[0062] Application Comparative Example 1: The application of a high-elasticity adhesive coating silicone rubber for webbing in the coating of nylon webbing is the same as in Application Example 1, except that the high-elasticity adhesive coating silicone rubber for webbing in Example 1 is replaced with the high-elasticity adhesive coating silicone rubber for webbing in Comparative Example 3.

[0063] Material performance testing: The high-elasticity adhesive coating silicone rubber tapes obtained in Examples 1-7 and Comparative Examples 1-4 were subjected to various performance tests, and the test methods are as follows: 1. Hardness (Shore A): Tested according to GB / T 531.1-2008 standard.

[0064] 2. Tensile strength and elongation at break: Tested in accordance with GB / T 528-2009 standard.

[0065] 3. Tear strength: Tested in accordance with GB / T 529-2008 standard.

[0066] 4. Tensile strength retention rate after heat aging: Place the sample in a 120℃ heat aging chamber for 72 hours, remove it and cool it to room temperature. Test the tensile strength according to the tensile strength test method. Calculate the tensile strength retention rate after heat aging using the following formula: Tensile strength value after aging / Tensile strength value before aging × 100%. The larger the value, the better the heat aging resistance.

[0067] 5. Surface drying time: Tested according to the finger touch method in GB / T 1728-2020 standard.

[0068] The test methods for the various performance tests of Application Examples 1-3 and Comparative Example 1 are as follows: 6. 180° peel strength: Tested according to GB / T 2792-2014 standard.

[0069] 7. Bending fatigue test: Take the webbing samples from Application Examples 1-3 and Comparative Example 1 respectively, cut them into strips of 150mm×25mm, and install them on a reciprocating testing machine equipped with a stainless steel cylindrical mandrel with R=5.0 mm. The silicone-coated side of the sample is facing outward, and it is bent 180° around the mandrel. The test frequency is 100 times / min, and the samples are observed periodically under a 10x magnifying glass. The appearance of cracks, peeling, or separation of the coating from the webbing is used as the criteria for failure judgment.

[0070] The test properties of the high-elasticity adhesive coating silicone rubber for Example 1-7 and Comparative Example 1-4 are shown in Table 1 below:

[0071] The test performance of Application Examples 1-3 and Comparative Example 1 is shown in Table 2 below:

[0072] The high-elasticity adhesive-coated webbing silicone rubber in Examples 1-7 achieves a balance of high elasticity, strong adhesion, and excellent weather resistance through the rational proportioning and synergistic effect of various raw material components, including vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, stearic acid-modified nano-calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, and hydrogen-containing silicone oil. Test results show that its tensile strength can reach up to 6.2 MPa, elongation at break ≥640%, and tensile strength retention rate after heat aging ≥95%. Application results in Example 1 show that the peel strength against nylon webbing reaches 25.4 N / cm, and the bending fatigue life exceeds 100,000 cycles, fully meeting the stringent requirements of high-end webbing for material strength, weather resistance, and reliable adhesion.

[0073] Compared with Example 1, Comparative Example 1 was prepared using the same method and with the same amount of raw materials. The difference was that the amount of α,ω-dihydroxypolydimethylsiloxane in Comparative Example 1 was 15g, which is higher than the range of α,ω-dihydroxypolydimethylsiloxane used in this application. The results showed that although the silicone rubber of Comparative Example 1 had the highest elongation at break (890%), its tensile strength (3.5MPa) and tear strength (12.1 kN / m) were the lowest among all samples, and its strength retention rate after heat aging (92%) was also low. This may be because the hydrogen-containing silicone oil needs to undergo both addition crosslinking with vinyl silicone oil and condensation crosslinking with α,ω-dihydroxypolydimethylsiloxane. Excessive α,ω-dihydroxypolydimethylsiloxane would consume more hydrogen-containing silicone oil, potentially leading to insufficient crosslinking of the main addition network and thus failing to form a sufficiently strong three-dimensional network structure.

[0074] Compared with Example 1, Comparative Example 2 was prepared using the same method and with the same amount of raw materials. The difference was that the amount of stearic acid-modified nano-calcium carbonate in Comparative Example 2 was increased to 25g, exceeding the range specified in this application. Results showed that the hardness of the silicone rubber in Comparative Example 2 significantly increased (55 Shore A), and the elongation at break decreased sharply to 520%. The silicone rubber in Comparative Example 2 became noticeably harder and its elasticity decreased. Simultaneously, its processing fluidity deteriorated, and the surface drying time was extended to 25min. This indicates that excessive stearic acid-modified nano-calcium carbonate may restrict the movement of polymer chains, severely impairing the high elasticity and workability of the silicone rubber.

[0075] Compared to Example 1, Comparative Example 3 did not use stearic acid-modified nano-calcium carbonate; instead, it was replaced with an equal amount of unmodified nano-calcium carbonate. The results showed that the silicone rubber in Comparative Example 3 exhibited significant shortcomings: its tensile strength (4.1 MPa) and tear strength (13.6 kN / m) were significantly lower than those in Example 1. Comparing Comparative Example 3's silicone rubber to nylon webbing with Application Comparative Example 1, and Application Example 1's silicone rubber to nylon webbing, the peel strength of Application Comparative Example 1 was only 12.3 N / cm, less than half that of Application Example 1. The flexural fatigue life of Application Comparative Example 1 also decreased sharply. This indicates that unmodified nano-calcium carbonate has poor dispersion in the matrix, easily forming interface defects, which not only weakens the strength of the material itself but also severely damages its bonding strength and durability with the webbing.

[0076] Compared with Example 1, Comparative Example 4 was prepared using the same method and with the same amount of raw materials. The difference was that the amount of auxiliary filler in Comparative Example 4 was increased to 3.5 g, which is higher than the range of this application. The results showed that the silicone rubber of Comparative Example 4 also exhibited problems such as increased hardness (52 Shore A), decreased elongation at break (580%), and significantly prolonged surface drying time (21 min). Therefore, it is necessary to strictly control the amount of auxiliary filler to balance the reinforcing effect and processing applicability.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A type of silicone rubber for high-elasticity adhesive coating of webbing, characterized in that, Its raw material components include: vinyl silicone oil, α,ω-dihydroxy polydimethylsiloxane, hydrogen-containing silicone oil, methyltriethoxysilane, nano calcium carbonate, γ-glycidyl etheroxypropyltrimethoxysilane, platinum catalyst, auxiliary filler, anti-yellowing agent, toughening agent; The nano-calcium carbonate has a particle size of 50-100 nm and is obtained by surface modification with stearic acid.

2. The high-elasticity adhesive coating silicone rubber for webbing as described in claim 1, characterized in that, The α,ω-dihydroxy polydimethylsiloxane has a number-average molecular weight of 50,000 to 100,000 and a viscosity of 5,000 to 15,000 mPa·s at 25°C.

3. The high-elasticity adhesive coating silicone rubber for webbing as described in claim 1, characterized in that, The hydrogen-containing silicone oil has a hydrogen content of 0.1~0.3wt% and a number average molecular weight of 1000~3000.

4. The high-elasticity adhesive coating silicone rubber for webbing as described in claim 1, characterized in that, The platinum catalyst is a chloroplatinic acid-vinylsiloxane complex, and the platinum content in the platinum catalyst is 500~1000 ppm by mass. And / or, the auxiliary filler is a compound of fumed silica and precipitated silica in a weight ratio of (1~3):(2~5).

5. The high-elasticity adhesive coating silicone rubber for webbing as described in claim 1, characterized in that, The anti-yellowing agent is a compound of hindered phenolic antioxidant and ultraviolet absorber in a weight ratio of (1~2.5):

1. The hindered phenolic antioxidant is selected from at least one of antioxidant 330, antioxidant 1010, antioxidant 1076, and antioxidant 3114. The ultraviolet absorber is selected from at least one of UV-327, UV-329, UV-571, and UV-1577.

6. The high-elasticity adhesive coating silicone rubber for webbing as described in claim 1, characterized in that, The toughening agent is hydroxyl-terminated polybutadiene or polyether polyol, wherein the polyether polyol is selected from at least one of polypropylene glycol, polytetrahydrofuran glycol, and polymethyltetrahydrofuran glycol.

7. The high-elasticity adhesive coating silicone rubber for webbing according to any one of claims 1 to 6, characterized in that, Its raw materials include the following components in parts by weight: 50-70 parts of vinyl silicone oil; 5-10 parts of α,ω-dihydroxypolydimethylsiloxane; 8-15 parts of hydrogen-containing silicone oil; 2-6 parts of methyltriethoxysilane; 10-20 parts of nano-calcium carbonate; 2-6 parts of γ-glycidyl etheroxypropyltrimethoxysilane; Platinum catalyst 0.01~0.05 parts; 1-3 parts of auxiliary filler; Anti-yellowing agent 0.8~2 parts; 2-5 parts toughening agent.

8. A method for preparing a high-elasticity adhesive coating silicone rubber for webbing as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix vinyl silicone oil, α,ω-dihydroxypolydimethylsiloxane, nano-calcium carbonate, auxiliary fillers and toughening agents, and heat to premix to obtain a premix; S2. Cool the premixed material, add hydrogen-containing silicone oil, methyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane, and continue mixing. S3. Add anti-yellowing agent and platinum catalyst, and after stirring, discharging and degassing, obtain the high-elasticity adhesive coating tape silicone rubber.

9. The method for preparing the high-elasticity adhesive coating silicone rubber for webbing according to claim 8, characterized in that, In step S1, the heating temperature is 80~100℃, the premixing speed is 30~50r / min, and the premixing time is 30~60min; In step S2, the temperature is reduced to 40~60℃, and the mixing time is 20~40min; In step S3, the stirring is carried out under nitrogen protection, the stirring temperature is 40~50℃, the stirring speed is 20~30 r / min, the stirring time is 15~25 min, and the degassing time is 10~20 min.

10. The application of a high-elasticity adhesive coating silicone rubber for webbing as described in any one of claims 1 to 7, or a high-elasticity adhesive coating silicone rubber for webbing prepared by the preparation method as described in any one of claims 8 to 9, in the coating of webbing surfaces.

Images