Two-component silicone rubber coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of silicone rubber coatings and discloses a two-component silicone rubber coating as well as a preparation method and application thereof. The two-component silicone rubber coating comprises a component A and a component B, wherein the component A is prepared from 60 to 70 parts of vinyl silicone oil, 15 to 20 parts of hydrogen-containing silane modified reinforcing filler, 5 to 10 parts of hydrogen-containing MQ silicon resin, 0.1 to 0.3 part of a catalyst and 1 to 3 parts of a tackifier 1; the component B is prepared from 60 to 70 parts of vinyl silicone oil, 15 to 20 parts of hydrogen-containing silane modified reinforcing filler, 5 to 10 parts of hydrogen-containing MQ silicon resin, 5 to 10 parts of hydrogen-terminated silicone oil cross-linking agent, 0.05 to 0.1 part of inhibitor and 1 to 3 parts of tackifier 2. The two-component silicone rubber coating disclosed by the invention has good operating performance, adhesive property, tensile property and tearing property, can be used as an automobile safety airbag coating material, and has the advantages of low cost and good performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicone rubber coatings, and in particular relates to a two-component silicone rubber coating, a preparation method and applications thereof. Background Art

[0002] Silicone rubber, due to its excellent physical and safety properties, is increasingly gaining popularity in automotive manufacturing and is being used in a growing number of automotive parts. Silicone rubber-coated textiles, produced by coating a liquid silicone rubber composition onto textiles and vulcanizing them at high temperatures to form a thin, flexible layer, are often used in airbags, among other applications, to improve airbag safety. This type of liquid silicone rubber is primarily used as a surface coating on fabrics to prevent air from passing through them, reducing their gas permeability and, to a certain extent, mitigate damage to the fabric from the hot gases generated by explosives within the airbag.

[0003] With the current increase in automobile sales, the market capacity for airbag silicone rubber is expected to reach 6,000 tons, 8,000 tons, and 10,000 tons in 2024, 2025, and 2026, respectively. Currently, this product is mainly imported, but silicone rubber has superior performance but is expensive. Domestic airbag manufacturers are actively promoting the localization of this product, and domestic new energy vehicle manufacturers also have localized silicone rubber requirements.

[0004] Airbag silicone rubber products require not only high elongation, high strength, and good adhesion, but also excellent spreadability to ensure even distribution of the rubber onto the fabric. However, the addition of high levels of reinforcing fillers to improve silicone rubber's strength can lead to reduced flexibility (elongation) and spreadability, creating a significant conflict. Balancing these factors is crucial. Developing a silicone rubber coating that exhibits excellent adhesion to fabric while also possessing high strength, high flexibility, and ease of application remains a challenge for those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a two-component silicone rubber coating.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned two-component silicone rubber coating.

[0007] Another object of the present invention is to provide the use of the above-mentioned two-component silicone rubber coating as an airbag coating.

[0008] The purpose of the present invention is achieved through the following technical solutions: A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil: 60-70 parts, hydrogenated silane modified reinforcing filler: 15-20 parts, hydrogenated MQ silicone resin: 5-10 parts, catalyst: 0.1-0.3 parts, tackifier: 1: 1-3 parts; The component B comprises the following ingredients in parts by weight: Vinyl silicone oil: 60~70 parts, hydrogen-containing silane modified reinforcing filler: 15~20 parts, hydrogen-containing MQ silicone resin: 5~10 parts, hydrogen-terminated silicone oil crosslinker: 5~10 parts, inhibitor: 0.05~0.1 parts, tackifier 2:1~3 parts.

[0009] Furthermore, in the component A and component B, the structural formula of the vinyl silicone oil is shown in the following formula I: Formula I, where n=200~700.

[0010] Furthermore, in the component B, the structural formula of the hydrogen-terminated silicone oil crosslinking agent is shown in the following formula II: Formula II, where n=10~50.

[0011] The present invention adopts a hydrogen-terminated silicone oil crosslinking agent in combination with a hydrogen-containing silane-modified reinforcing filler and a hydrogen-containing MQ silicone resin. The hydrogen-containing silane-modified reinforcing filler and the hydrogen-containing MQ silicone resin form a high-density crosslinking network with the vinyl silicone oil to improve the strength of the silicone rubber. At the same time, the hydrogen-terminated silicone oil crosslinking agent and the vinyl silicone oil form a low-density crosslinking network to maintain the good flexibility of the silicone rubber.

[0012] Furthermore, in the components A and B, the hydrogen-containing silane-modified reinforcing filler is preferably fumed silica surface-modified with trimethoxyhydrogensilane or triethoxyhydrogensilane. More preferably, the specific surface area of the fumed silica is 200-400 m 2 / g; the amount of trimethoxyhydrogen silane or triethoxyhydrogen silane is 0.5~5% of the mass of fumed silica. The larger the specific surface area of the reinforcing filler, the better the reinforcement, but the cost is higher. The surface modification method of silane coupling agent is a commonly used method in this field, such as dry modification or wet modification. Dry modification can be carried out by directly mixing the hydrogen-containing silane coupling agent with fumed silica in a high-speed mixer; wet modification can be carried out by dissolving the hydrogen-containing silane coupling agent in an organic solvent and then mixing it with fumed silica. The present invention introduces silicon hydrogen groups with cross-linking activity on the surface of the reinforcing filler by using hydrogen-containing silane to modify the reinforcing filler. On the one hand, it improves the mixing and dispersion effect of the reinforcing filler in the base rubber, and on the other hand, it can form a high-density cross-linking network with vinyl silicone oil, significantly improving the reinforcement effect; on the other hand, surface modification by hydrogen-containing silane can reduce the surface polarity of SiO2, thereby reducing the viscosity of the mixed rubber and improving the ease of coating of the rubber.

[0013] Furthermore, in components A and B, the hydrogenated MQ silicone resin has an M / Q value of 0.8-1.2, a molecular weight of 2000-4000, and a hydrogen content of 0.1-0.5% (mass content). The hydrogenated MQ silicone resin in the present invention primarily serves the purpose of synergistic reinforcement and regulating the viscosity of the rubber compound. Normally, using high-molecular-weight vinyl silicone oil as a raw material and employing a high content of fumed silica reinforcing filler will result in higher silicone rubber strength. However, excessively high molecular weight of the vinyl silicone oil or excessive content of fumed silica reinforcing filler will result in excessively high rubber viscosity, impacting back-end use. The present invention uses a lower molecular weight hydrogenated MQ silicone resin for synergistic reinforcement. The silicon hydrogen groups it contains can form a high-density cross-linked network with the vinyl silicone oil, which can improve the strength of the silicone rubber while maintaining the appropriate viscosity for use.

[0014] Furthermore, the catalyst in component A is a platinum catalyst, such as chloroplatinic acid or a platinum complex catalyst. Its primary function is to catalyze the hydrosilylation curing reaction of the vinyl silicone oil with the hydrogen-containing silane-modified reinforcing filler, the hydrogen-containing MQ silicone resin, and the mid-terminal hydrogen silicone oil crosslinker in component B.

[0015] Furthermore, in the component B, the inhibitor is tetramethyltetravinylcyclotetrasiloxane or ethynylcyclohexanol. Its main function is to inhibit the hydrosilylation reaction of the vinyl silicone oil, silicone resin and crosslinking agent in the component B, thereby improving the stability of the component.

[0016] Furthermore, in the component A, the tackifier 1 is any one of isopropyl titanate, n-butyl titanate, titanium isooctanoate, zirconium tetraisopropoxide, zirconium isooctanoate, and zirconium tetraacetylacetonate. Its main working principle is that the titanium atom in the titanate molecule forms a chemical bond with the surface of the inorganic substrate through an ester exchange reaction (Ti-OM, M is the substrate metal or oxide), and the long-chain organic group at the other end is physically entangled or chemically cross-linked with the organic matrix of the silicone rubber (such as vinyl silicone oil) to form an "inorganic-organic" bridge, thereby reducing the interfacial energy. The zirconium ion (Zr 4+ ) has strong Lewis acidity and can coordinate with the hydrogen atoms in hydrogen-containing silicone oil (Si-H bond), reducing the activation energy of the hydrosilylation reaction and forming a synergistic catalytic mechanism with the platinum catalyst. This action promotes curing and bonding.

[0017] Furthermore, in component B, tackifier 2 is any one of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, and epoxy-modified polydimethylsiloxane (including pendant epoxy-modified polydimethylsiloxane and terminal epoxy-modified polydimethylsiloxane). The main mechanism of action is as follows: the methoxy (-OCH3) or ethoxy (-OC2H5) groups in the tackifier hydrolyze to form silanols, which condense with hydroxyl groups on the surface of the substrate and reinforcing filler to form Si-OM bonds. The epoxy (-O-CH2-CHO-) groups in the tackifier undergo a ring-opening reaction with Si-H bonds or hydroxyl-containing components in the silicone rubber to form a covalent crosslinked network. Furthermore, the epoxy or amino (-NH2) groups in the tackifier strengthen the polar connection with the bonding substrate, thereby significantly improving the bonding effect.

[0018] The preparation method of the above-mentioned two-component silicone rubber coating comprises the following preparation steps: (1) Weigh each component by weight, first knead and stir part of the vinyl silicone oil and the hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 to 5 hours, then knead and stir at 150 to 180°C under vacuum for 2 to 3 hours to obtain a base rubber, cool to room temperature, then add the base rubber, catalyst, hydrogen-containing MQ silicone resin, tackifier 1 and the remaining vinyl silicone oil into a power mixer, stir and deaerate under room temperature and vacuum to obtain component A with a viscosity of 180,000 to 270,000 mPa·s; (2) Weigh each component by weight, first knead and stir the vinyl silicone oil and hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 to 5 hours, then knead and stir at 150 to 180°C under vacuum for 2 to 3 hours to obtain a base rubber, cool to room temperature, then add the base rubber, hydrogen-terminated silicone oil crosslinker, hydrogen-containing MQ silicone resin, inhibitor and thickener 2 into a power mixer, stir and deaerate under room temperature and vacuum to obtain component B with a viscosity of 200,000 to 300,000 mPa·s.

[0019] The above two-component silicone rubber coating is used as an airbag coating.

[0020] Furthermore, the application method is: mixing component A and component B evenly at room temperature, coating the mixture on the surface of the airbag substrate, and then performing a heating and curing treatment to obtain the airbag coating.

[0021] Further preferably, in the application method, the weight ratio of component A to component B is 1:1.

[0022] Further preferably, in the application method, the temperature of the heating and curing treatment is 160-180° C., and the time is 1-2 minutes.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The two-component silicone rubber coating of the present invention utilizes a hydrogen-containing silane-modified reinforcing filler and a specific hydrogen-containing MQ silicone resin for synergistic reinforcement, and is used in conjunction with a hydrogen-terminated silicone oil crosslinker. Utilizing the high- and low-density dual crosslinking network formed by the hydrogen-containing silane and vinyl silicone oil, the resulting rubber compound has the advantages of both high strength and high elongation. Furthermore, the use of hydrogen-containing silane-modified reinforcing fillers and the use of a relatively low molecular weight hydrogen-containing MQ silicone resin for synergistic reinforcement can also avoid the high viscosity of the rubber compound caused by the use of high-content, high-specific-surface-area fumed silica reinforcing fillers, which affects the back-end use, thereby improving the ease of coating of the rubber compound.

[0024] (2) The present invention adds specific tackifier 1 and tackifier 2 to the two-component silicone rubber coating. The synergistic use of the two can significantly improve the adhesion of the rubber to the airbag substrate without affecting the stability and ease of coating of the rubber.

[0025] (3) The automobile airbag coating material of the present invention has similar handling performance, bonding performance, tensile performance and tearing performance to imported ones, and is low in cost, simple in preparation method and easy to use. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0027] Example 1 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 25,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 200 m 2 / g of fumed silica surface-modified with 2.5wt% trimethoxysilane): 18 parts, hydrogenated MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.2 parts, and adhesion promoter 1 (isopropyl titanate): 2 parts.

[0028] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 25,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 200 m 2 / g of fumed silica surface modified with 2.5wt% trimethoxysilane): 18 parts, hydrogenated MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 1500): 8 parts, inhibitor (ethynyl cyclohexanol): 0.06 parts, and adhesion promoter 2 (γ-glycidyloxypropyltrimethoxysilane): 2 parts.

[0029] The two-component silicone rubber coating of this embodiment is prepared by the following method: (1) Weigh each component by weight. First, knead and stir 40 parts of vinyl silicone oil and 18 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool to room temperature, then add the base rubber, 0.2 parts of catalyst, 5 parts of hydrogen-containing MQ silicone resin, 2 parts of isopropyl titanate, and 25 parts of vinyl silicone oil into a power mixer. Stir and deaerate at room temperature under vacuum for 1 hour to obtain component A. The viscosity of the obtained component A is 180,000 mPa·s.

[0030] (2) Weigh each component by weight. First, knead and stir 65 parts of vinyl silicone oil and 18 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, and then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool the mixture to room temperature, then add the base rubber, 8 parts of a crosslinking agent, 5 parts of hydrogen-containing MQ silicone resin, 2 parts of γ-glycidyloxypropyltrimethoxysilane, and 0.06 parts of an inhibitor into a power mixer, and stir and deaerate at room temperature under vacuum for 1 hour to obtain component B. The viscosity of the obtained component B is 200,000 mPa·s.

[0031] Example 2 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 35,000): 60 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 250 m 2 / g of fumed silica surface-modified with 3.5wt% triethoxysilane): 15 parts, hydrogenated MQ silicone resin (M / Q value of 0.8, molecular weight of 4000, hydrogen content of 0.1%): 5 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.1 parts, and adhesion promoter 1 (zirconium tetraacetylacetonate): 2 parts.

[0032] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 35,000): 60 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 250 m 2 / g of fumed silica surface modified with 3.5wt% triethoxysilane): 15 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 3000): 5 parts, inhibitor (tetramethyltetravinylcyclotetrasiloxane): 0.05 parts, hydrogen-containing MQ silicone resin (M / Q value of 0.8, molecular weight of 4000, hydrogen content of 0.1%): 5 parts, adhesion promoter 2 (glycidoxypropylmethyldimethoxysilane): 2 parts.

[0033] The two-component silicone rubber coating of this embodiment is prepared by the following method: (1) Weigh each component by weight. First, knead and stir 35 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 hours, then knead and stir at 170°C under vacuum for 2 hours to obtain a base rubber. Cool the mixture to room temperature, then add the base rubber, 0.1 parts of catalyst, 5 parts of hydrogen-containing MQ silicone resin, 2 parts of zirconium tetraacetylacetonate, and 25 parts of vinyl silicone oil into a power mixer, stir and deaerate at room temperature under vacuum for 1 hour to obtain component A. The viscosity of the obtained component A is 190,000 mPa·s.

[0034] (2) Weigh each component by weight. First, knead and stir 60 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 hours, and then knead and stir at 170°C under vacuum for 2 hours to obtain a base rubber. Cool the mixture to room temperature, then add the base rubber, 5 parts of a cross-linking agent, 0.05 parts of an inhibitor, 5 parts of hydrogen-containing MQ silicone resin, and 2 parts of glycidoxypropylmethyldimethoxysilane into a power mixer, and stir and deaerate at room temperature under vacuum for 1 hour to obtain component B. The viscosity of the obtained component B is 210,000 mPa·s.

[0035] Example 3 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 52,000): 70 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 300 m 2 / g of fumed silica surface-modified with 1.5wt% trimethoxysilane): 20 parts, hydrogenated MQ silicone resin (M / Q value of 1.2, molecular weight of 2000, hydrogen content of 0.5%): 5 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.3 parts, and adhesion promoter 1 (n-butyl titanate): 3 parts.

[0036] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 52,000): 70 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 300 m 2 / g of fumed silica surface modified with 1.5wt% trimethoxysilane): 20 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 1500): 10 parts, inhibitor (tetramethyltetravinylcyclotetrasiloxane): 0.1 parts, hydrogen-containing MQ silicone resin (M / Q value of 1.2, molecular weight of 2000, hydrogen content of 0.5%): 5 parts, adhesion promoter 2 (γ-aminopropyltriethoxysilane): 3 parts.

[0037] The two-component silicone rubber coating of this embodiment is prepared by the following method: (1) Weigh each component by weight. First, knead and stir 45 parts of vinyl silicone oil and 20 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 5 hours, then knead and stir at 160°C under vacuum for 3 hours to obtain a base rubber. Cool to room temperature, then add the base rubber, 0.3 parts of catalyst, 5 parts of hydrogen-containing MQ silicone resin, 3 parts of n-butyl titanate, and 25 parts of vinyl silicone oil into a power mixer. Stir and deaerate at room temperature under vacuum for 1 hour to obtain component A. The viscosity of the obtained component A is 220,000 mPa·s.

[0038] (2) Weigh each component by weight. First, knead and stir 70 parts of vinyl silicone oil and 20 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 5 hours, and then knead and stir at 160°C under vacuum for 3 hours to obtain a base rubber. Cool to room temperature, then add the base rubber, 10 parts of a cross-linking agent, 0.1 parts of an inhibitor, 5 parts of hydrogen-containing MQ silicone resin, and 3 parts of γ-aminopropyltriethoxysilane into a power mixer. Stir and deaerate at room temperature under vacuum for 1 hour to obtain component B. The viscosity of the obtained component B is 235,000 mPa·s.

[0039] Example 4 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 31,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 350 m 2 / g of fumed silica surface-modified with 1.0wt% trimethoxysilane): 18 parts, hydrogenated MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.2 parts, and adhesion promoter 1 (titanium isooctanoate): 2 parts.

[0040] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 31,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 350 m 2 / g of fumed silica surface modified with 1.0wt% trimethoxysilane): 18 parts, hydrogenated MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 1000): 8 parts, inhibitor (ethynyl cyclohexanol): 0.06 parts, and adhesion promoter 2 (γ-glycidyloxypropyltriethoxysilane): 2 parts.

[0041] The preparation method of the two-component silicone rubber coating of this embodiment is the same as that of Example 1. The viscosity of the obtained component A is 250,000 mPa·s. The viscosity of the obtained component B is 270,000 mPa·s.

[0042] Example 5 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 15,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 400 m 2 / g of fumed silica surface-modified with 0.5wt% trimethoxysilane): 16 parts, hydrogenated MQ silicone resin (M / Q value of 0.8, molecular weight of 4000, hydrogen content of 0.1%): 8 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.2 parts, and adhesion promoter 1 (zirconium isooctanoate): 3 parts.

[0043] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 15,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 400 m 2 / g of fumed silica surface modified with 0.5wt% trimethoxysilane): 16 parts, hydrogenated MQ silicone resin (M / Q value of 0.8, molecular weight of 4000, hydrogen content of 0.1%): 8 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 3800): 8 parts, inhibitor (ethynyl cyclohexanol): 0.06 parts, tackifier 2 (side chain epoxy-modified polydimethylsiloxane, commercially available, epoxy content of 4.5wt%, weight-average molecular weight of 8000): 1 part.

[0044] The two-component silicone rubber coating of this embodiment is prepared by the following method: (1) Weigh each component by weight. First, knead and stir 40 parts of vinyl silicone oil and 16 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, and then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool to room temperature, then add the base rubber, 0.2 parts of catalyst, 8 parts of hydrogen-containing MQ silicone resin, 3 parts of zirconium isooctanoate, and 25 parts of vinyl silicone oil into a power mixer. Stir and deaerate at room temperature under vacuum for 1 hour to obtain component A. The viscosity of the obtained component A is 270,000 mPa·s.

[0045] (2) Weigh each component by weight. First, knead and stir 65 parts of vinyl silicone oil and 16 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, and then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool the mixture to room temperature, then add the base rubber, 8 parts of a crosslinking agent, 8 parts of hydrogen-containing MQ silicone resin, 1 part of a side-chain epoxy-modified polydimethylsiloxane, and 0.06 parts of an inhibitor into a power mixer. Stir and degas under room temperature and vacuum for 1 hour to obtain component B. The viscosity of the obtained component B is 300,000 mPa·s.

[0046] Example 6 A two-component silicone rubber coating comprises component A and component B, wherein component A comprises the following components in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 45,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 300 m 2 / g of fumed silica surface-modified with 5wt% triethoxysilane): 15 parts, hydrogenated MQ silicone resin (M / Q value of 1.2, molecular weight of 2000, hydrogen content of 0.5%): 10 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.2 parts, and adhesion promoter 1 (zirconium tetraisopropoxide): 1 part.

[0047] The component B comprises the following ingredients in parts by weight: Vinyl silicone oil (vinyl-terminated silicone oil with a weight average molecular weight of 45,000): 65 parts, hydrogenated silane-modified reinforcing filler (specific surface area of 300 m 2 / g of fumed silica surface modified with 5wt% triethoxysilane): 15 parts, hydrogenated MQ silicone resin (M / Q value of 1.2, molecular weight of 2000, hydrogen content of 0.5%): 10 parts, crosslinking agent (hydrogen-terminated silicone oil with a weight-average molecular weight of 800): 8 parts, inhibitor (ethynyl cyclohexanol): 0.06 parts, tackifier 2 (epoxy-terminated modified polydimethylsiloxane, commercially available, epoxy content of 2.1wt%, weight-average molecular weight of 4000): 3 parts.

[0048] The two-component silicone rubber coating of this embodiment is prepared by the following method: (1) Weigh each component by weight. First, knead and stir 40 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, and then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool to room temperature, then add the base rubber, 0.2 parts of catalyst, 10 parts of hydrogen-containing MQ silicone resin, 1 part of zirconium tetraisopropoxide, and 25 parts of vinyl silicone oil into a power mixer. Stir and deaerate at room temperature under vacuum for 1 hour to obtain component A. The viscosity of the obtained component A is 220,000 mPa·s.

[0049] (2) Weigh each component by weight. First, knead and stir 65 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 4 hours, and then knead and stir at 180°C under vacuum for 2.5 hours to obtain a base rubber. Cool the mixture to room temperature, then add the base rubber, 8 parts of a crosslinking agent, 10 parts of hydrogen-containing MQ silicone resin, 3 parts of epoxy-terminated modified polydimethylsiloxane, and 0.06 parts of an inhibitor into a power mixer. Stir and degas under room temperature and vacuum for 1 hour to obtain component B. The viscosity of the obtained component B is 240,000 mPa·s.

[0050] Comparative Example 1 A two-component silicone rubber coating, compared with Example 1, component A and component B use unmodified reinforcing fillers (specific surface area of 200m 2 / g of fumed silica) to replace the hydrogen-containing silane-modified reinforcing filler, and the rest are the same.

[0051] Comparative Example 2 A two-component silicone rubber coating is prepared. Compared with Example 1, no hydrogenated MQ silicone resin is added to component A and component B, and the amount of hydrogenated silane-modified reinforcing filler added is increased to 23 parts, while the rest of the ingredients remain the same.

[0052] Comparative Example 3 A two-component silicone rubber coating is provided. Compared with Example 1, the crosslinking agent in component B is a side chain hydrogen-containing silicone oil with a weight-average molecular weight of 1500, and the rest are the same.

[0053] Comparative Example 4 A two-component silicone rubber coating is prepared. Compared with Example 1, tackifier 1 is not added to component A, and the content of tackifier 2 is increased to 4 parts, while the rest of the components remain the same.

[0054] Comparative Example 5 A two-component silicone rubber coating is prepared. Compared with Example 1, tackifier 2 is not added to component B, and the content of tackifier 1 is increased to 4 parts, while the rest of the components remain the same.

[0055] The two-component silicone rubber coatings obtained in the above examples and comparative examples are used as airbag coatings. The specific application method is as follows: Component A and Component B are mixed at a weight ratio of 1:1 at room temperature, and then coated on the surface of the airbag substrate (PET). The mixture is then heated to 160-180°C and cured for 2 minutes to obtain the airbag coating.

[0056] The adhesion, tensile and tear properties of the two-component silicone rubber coatings obtained in the above examples and comparative examples were tested. The tensile strength and elongation tests were conducted in accordance with GB / T 528-2009, the tear strength test was conducted in accordance with GB / T 529-2008, and the peel strength test was conducted in accordance with GB / T 2792-2014. The results are shown in Table 1 below: Table 1 Test results Test items Viscosity (mPa.s) Tensile strength (MPa) Tear strength (kN / m) Elongation at break (%) Peel force (N) Example 1 A: 180,000 B: 200,000 5.1 11.5 850 42 Example 2 A: 190,000 B: 210,000 5.5 12.3 930 45 Example 3 A: 220,000 B: 235,000 6.2 14.6 980 48 Example 4 A: 250,000 B: 270,000 5.2 11.9 810 52 Example 5 A: 270,000 B: 300,000 4.9 10.4 900 45 Example 6 A: 220,000 B: 240,000 6.6 15.7 720 47 Comparative Example 1 A: 350,000 B: 400,000 4.0 9.3 710 44 Comparative Example 2 A: 220,000 B: 260,000 3.8 8.3 650 35 Comparative Example 3 A: 180,000 B: 200,000 5.2 11.8 510 44 Comparative Example 4 A: 180,000 B: 200,000 5.0 11.2 860 20 Comparative Example 5 A: 180,000 B: 200,000 5.1 11.6 850 10

[0057] Comparison of the results of Comparative Example 1 with Example 1 shows that the reinforcing filler modified with hydrogen-containing silanes in the present invention significantly improves the mechanical properties of silicone rubber coatings compared to unmodified reinforcing fillers. This is because surface modification with hydrogen-containing silanes enhances the mixing and dispersion of the reinforcing filler in the base rubber and, during the subsequent curing process, forms a high-density cross-linked network with the vinyl silicone oil, significantly improving the reinforcing effect. Furthermore, the reinforcing filler modified with hydrogen-containing silanes can significantly reduce the viscosity of the rubber and improve its coating properties. This is because surface modification with hydrogen-containing silanes reduces the surface polarity of SiO2, thereby reducing the viscosity of the mixed rubber.

[0058] Comparison of Comparative Example 2 with Example 1 shows that the present invention employs a low-molecular-weight hydrogenated MQ silicone resin for synergistic reinforcement, significantly improving the mechanical properties of silicone rubber coatings and reducing the viscosity of the rubber compound to a certain extent, ensuring good scraping performance. The strength of silicone rubber is primarily affected by the ratio of the molecular weight of the silicone oil to the reinforcing filler, as well as the specific surface area of the filler (generally, a larger specific surface area results in better reinforcement, but also higher rubber viscosity). However, blindly employing high-molecular-weight silicone oils, high-ratio reinforcing fillers with high specific surface areas to enhance silicone rubber strength can result in excessively high rubber viscosity, impacting scraping performance. The present invention employs a low-molecular-weight hydrogenated MQ silicone resin, which forms a high-density cross-linked network with the vinyl silicone oil during the subsequent curing process and exhibits a relatively low viscosity prior to curing, thereby providing synergistic reinforcement while improving the scraping performance of the rubber compound.

[0059] From the comparison results of Comparative Example 3 and Example 1, it can be seen that the use of side-chain hydrogenated silicone oil as a crosslinker will lead to a significant decrease in the flexibility of the silicone rubber coating. The reason is that the use of side-chain hydrogenated silicone oil as a crosslinker will lead to an excessively large overall crosslinking density of the silicone rubber coating after curing. However, by using the hydrogenated silicone oil crosslinker of the present invention in combination with hydrogenated silane-modified reinforcing filler and hydrogenated MQ silicone resin, and utilizing the high and low density dual crosslinking network formed by the hydrogenated silicone oil and the vinyl silicone oil, the resulting silicone rubber coating has the advantages of both high strength and high elongation.

[0060] By comparing the results of Examples 4 and 5 with Example 1, it can be seen that the present invention uses tackifier 1 to act as an adhesion promoter for the product, and uses tackifier 2 to play the main bonding role. The combination of the two can greatly improve the adhesion of silicone rubber to the substrate.

[0061] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A two-component silicone rubber coating, characterized in that: The invention comprises component A and component B, wherein component A comprises the following ingredients in parts by weight: Vinyl silicone oil: 60-70 parts, hydrogenated silane modified reinforcing filler: 15-20 parts, hydrogenated MQ silicone resin: 5-10 parts, catalyst: 0.1-0.3 parts, tackifier: 1: 1-3 parts; The component B comprises the following ingredients in parts by weight: Vinyl silicone oil: 60~70 parts, hydrogen-containing silane modified reinforcing filler: 15~20 parts, hydrogen-containing MQ silicone resin: 5~10 parts, hydrogen-terminated silicone oil crosslinker: 5~10 parts, inhibitor: 0.05~0.1 parts, tackifier 2:1~3 parts.

2. A two-component silicone rubber coating according to claim 1, characterized in that: In the components A and B, the structural formula of the vinyl silicone oil is shown in the following formula I: Formula I, where n = 200~700; In the component B, the structural formula of the hydrogen-terminated silicone oil crosslinking agent is shown in the following formula II: Formula II, where n=10~50.

3. The two-component silicone rubber coating according to claim 1, characterized in that: In the component A and the component B, the hydrogen-containing silane-modified reinforcing filler is fumed silica whose surface is modified by trimethoxyhydrogensilane or triethoxyhydrogensilane.

4. A two-component silicone rubber coating according to claim 3, characterized in that: The specific surface area of the fumed silica is 200-400 m 2 / g; the amount of trimethoxysilane or triethoxysilane is 0.5~5% of the mass of fumed silica.

5. The two-component silicone rubber coating according to claim 1, characterized in that: In the components A and B, the hydrogen-containing MQ silicone resin has an M / Q value of 0.8-1.2, a molecular weight of 2000-4000, and a hydrogen content of 0.1-0.5%.

6. The two-component silicone rubber coating according to claim 1, characterized in that: In the component A, the catalyst is a platinum catalyst; in the component B, the inhibitor is tetramethyltetravinylcyclotetrasiloxane or ethynylcyclohexanol.

7. The two-component silicone rubber coating according to claim 1, characterized in that: In the component A, the viscosity enhancer 1 is any one of isopropyl titanate, n-butyl titanate, titanium isooctanoate, zirconium tetraisopropoxide, zirconium isooctanoate, and zirconium tetraacetylacetonate; in the component B, the viscosity enhancer 2 is any one of γ-glycidyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, and epoxy-modified polydimethylsiloxane.

8. The method for preparing a two-component silicone rubber coating according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: (1) Weigh each component by weight, first knead and stir part of the vinyl silicone oil and the hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 to 5 hours, then knead and stir at 150 to 180°C under vacuum for 2 to 3 hours to obtain a base rubber, cool to room temperature, then add the base rubber, catalyst, hydrogen-containing MQ silicone resin, tackifier 1 and the remaining vinyl silicone oil into a power mixer, stir and deaerate under room temperature and vacuum to obtain component A with a viscosity of 180,000 to 270,000 mPa·s; (2) Weigh each component by weight, first knead and stir the vinyl silicone oil and hydrogen-containing silane-modified reinforcing filler at room temperature and pressure for 3 to 5 hours, then knead and stir at 150 to 180°C under vacuum for 2 to 3 hours to obtain a base rubber, cool to room temperature, then add the base rubber, hydrogen-terminated silicone oil crosslinker, hydrogen-containing MQ silicone resin, inhibitor and thickener 2 into a power mixer, stir and deaerate under room temperature and vacuum to obtain component B with a viscosity of 200,000 to 300,000 mPa·s.

9. Use of a two-component silicone rubber coating according to any one of claims 1 to 7 as an airbag coating, characterized in that: The application method is as follows: uniformly mixing component A and component B at room temperature, coating the mixture on the surface of the airbag substrate, and then performing a heating and curing treatment to obtain the airbag coating.

10. The use according to claim 9, characterized in that In the application method, the weight ratio of component A to component B is 1:1; the temperature of the heating and curing treatment is 160-180° C., and the time is 1-2 minutes.

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