Two-component silicone rubber coating, preparation method and application thereof

Abstract

The application belongs to the technical field of silicone rubber coating and discloses a two-component silicone rubber coating, a preparation method and application thereof. The two-component silicone rubber coating comprises component A and component B. The component A comprises the following components: 60-70 parts of vinyl silicone oil, 15-20 parts of hydrogen-containing silane modified reinforcing filler, 5-10 parts of hydrogen-containing MQ silicone resin, 0.1-0.3 parts of a catalyst, and 1-3 parts of tackifier 1. The component B comprises the following components: 60-70 parts of vinyl silicone oil, 15-20 parts of hydrogen-containing silane modified reinforcing filler, 5-10 parts of hydrogen-containing MQ silicone resin, 5-10 parts of hydrogen-terminated silicone oil crosslinking agent, 0.05-0.1 parts of an inhibitor, and 1-3 parts of tackifier 2. The two-component silicone rubber coating has good operation performance, bonding performance, tensile performance and tear performance, can be used for automobile airbag coating materials, and has the advantages of low cost and good performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of silicone rubber coating, and particularly relates to a two-component silicone rubber coating, a preparation method and application thereof. BACKGROUND

[0002] Silicone rubber has excellent physical properties and safety performance, and gradually highlights the advantages in automobile manufacturing, and is increasingly used in automobile parts. Liquid silicone rubber composition is coated on a textile and vulcanized at high temperature to form a thin layer of flexible body, and the prepared silicone rubber coated textile is often applied to the safety airbag of a vehicle, which can improve the safety of the safety airbag. Such liquid silicone rubber is mainly suitable for fabric surface coating to prevent air from penetrating the fabric, reduce the gas permeability of the fabric, and to some extent, slow down the damage of the hot gas generated by the explosion in the airbag to the fabric.

[0003] With the increase in the sales of automobiles, it is predicted that the market capacity of safety airbag silicone rubber in 2024, 2025 and 2026 will be 6000t, 8000t and 10000t, respectively. At present, such products are mainly imported, and the silicone rubber has superior performance and high price. At present, domestic safety airbag manufacturers are actively promoting the localization of such products, and domestic new energy vehicle manufacturers also have localization requirements for silicone rubber.

[0004] In addition to the high elongation, high strength and good adhesion of the safety airbag silicone rubber product, it also needs to have good drawdown performance, so that the sizing material can be uniformly distributed on the fabric. However, in order to improve the strength of the silicone rubber, a high content of reinforcing filler needs to be added, which will cause the flexibility (elongation) and drawdown performance of the product to decrease, which is very contradictory. Balancing these factors is the key, and how to obtain a silicone rubber coating with good adhesion to fabric and at the same time high strength, high flexibility and easy to coat is still a problem to be solved by those skilled in the art. SUMMARY

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

[0006] Another purpose of the present application is to provide a preparation method of the two-component silicone rubber coating.

[0007] Still another purpose of the present application is to provide the application of the two-component silicone rubber coating as a safety airbag coating.

[0008] The purposes of the present application are achieved by the following technical solutions.

[0009] A two-component silicone rubber coating comprises component A and component B, wherein the component A comprises the following components in parts by weight:

[0010] vinyl silicone oil: 60~70 parts, hydrogen-containing silane modified reinforcing filler: 15~20 parts, hydrogen-containing MQ silicone resin: 5~10 parts, catalyst: 0.1~0.3 parts, tackifier 1: 1~3 parts;

[0011] The component B comprises the following ingredients by weight:

[0012] 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 crosslinking agent: 5~10 parts, inhibitor: 0.05~0.1 parts, tackifier 2: 1~3 parts.

[0013] Further, in the component A and the component B, the structural formula of the vinyl silicone oil is shown in the following formula I:

[0014] Formula I, wherein n=200~700.

[0015] Further, in the component B, the structural formula of the hydrogen-terminated silicone oil crosslinking agent is shown in the following formula II:

[0016] Formula II, wherein n=10~50.

[0017] The present application uses the hydrogen-terminated silicone oil crosslinking agent in combination with the hydrogen-containing silane modified reinforcing filler and the hydrogen-containing MQ silicone resin, wherein 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, and the hydrogen-terminated silicone oil crosslinking agent forms a low-density crosslinking network with the vinyl silicone oil to maintain the good flexibility of the silicone rubber.

[0018] Further, in the component A and the component B, the hydrogen-containing silane modified reinforcing filler preferably uses fumed silica surface modified by trimethoxysilane or triethoxysilane. More preferably, the specific surface area of the fumed silica is 200~400m 2The amount of trimethoxysilane or triethoxysilane is 0.5-5% of the mass of fumed silica. The larger the specific surface area of the reinforcing filler, the better the reinforcing effect, but the cost is higher. The surface modification method of the silane coupling agent is a method commonly used in the art, which can be modified by a dry method or a wet method. The dry modification can directly mix the hydrogen-containing silane coupling agent with the fumed silica in a high-speed mixer for modification; the wet modification can mix the hydrogen-containing silane coupling agent dissolved in an organic solvent with the fumed silica for modification. In the present application, the hydrogen-containing silane is used to modify the reinforcing filler to introduce silicon hydrogen groups with crosslinking activity on the surface of the reinforcing filler, which can improve the mixing and dispersion effect of the reinforcing filler in the base rubber, form a high-density crosslinking network with the vinyl silicone oil, and significantly improve the reinforcing effect; on the other hand, the surface modification by the hydrogen-containing silane can reduce the polarity of the SiO2 surface, thereby reducing the viscosity of the mixed rubber compound and improving the ease of coating of the rubber compound.

[0019] Further, in the components A and B, the M / Q value of the hydrogen-containing MQ silicone resin is 0.8-1.2, the molecular weight is 2000-4000, and the hydrogen content is 0.1-0.5% (mass content). The hydrogen-containing MQ silicone resin in the present application mainly plays a synergistic reinforcing and viscosity adjusting role. Normally, high molecular weight vinyl silicone oil is used as a raw material and high content fumed silica reinforcing filler is used, and the strength of the silicone rubber is higher. However, too high molecular weight of the vinyl silicone oil or too high content of the fumed silica reinforcing filler will result in too high viscosity of the rubber compound, which affects the use of the downstream. The present application uses a lower molecular weight hydrogen-containing MQ silicone resin for synergistic reinforcement, and the silicon hydrogen groups contained therein can form a high-density crosslinking network with the vinyl silicone oil, which can improve the strength of the silicone rubber while maintaining the rubber compound at a suitable use viscosity.

[0020] Further, in the component A, the catalyst is a platinum gold catalyst, such as chloroplatinic acid, platinum complex catalyst, etc. The main role is to catalyze the silicon hydrogen addition curing reaction of the vinyl silicone oil, the hydrogen-containing silane modified reinforcing filler, the hydrogen-containing MQ silicone resin, and the end hydrogen silicone oil crosslinking agent in component B.

[0021] Further, in the component B, the inhibitor is tetramethyltetavinylcyclotetrasiloxane or ethynylcyclohexanol. The main role is to inhibit the silicon hydrogen addition reaction of the vinyl silicone oil, the silicone resin, and the crosslinking agent in component B, and to improve the stability of the component.

[0022] Further, in the component A, the adhesion promoter 1 is any one of isopropyl titanate, n-butyl titanate, titanium isooctylate, zirconium tetraisopropoxide, zirconium isooctylate, and zirconium tetraacetylacetonate. The main principle of action is that the titanium atom in the titanate molecule forms a chemical bond (Ti-O-M, M is the substrate metal or oxide) with the surface of the inorganic substrate through ester exchange reaction, and the long-chain organic group at the other end physically entangles or chemically crosslinks with the organic matrix (such as vinyl silicone oil) of the silicone rubber, forming an "inorganic-organic" bridge to reduce the interfacial energy. Zirconium ions (Zr 4+ ) have strong Lewis acidity and can coordinate with 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 platinum catalyst. The above-mentioned effects promote curing and bonding.

[0023] Further, in the component B, the adhesion promoter 2 is any one of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, epoxypropoxypropylmethyldimethoxysilane, and epoxy-modified polydimethylsiloxane (including side-chain epoxy-modified polydimethylsiloxane and end-epoxy-modified polydimethylsiloxane). The main principle of action is that the methoxy group (-OCH3) or ethoxy group (-OC2H5) in the adhesion promoter hydrolyzes to form silanol, which condenses with the surface hydroxyl groups of the substrate and reinforcing filler to form Si-O-M bonds; the epoxy group (-O-CH2-CHO-) contained therein can undergo ring-opening reaction with Si-H bonds in the silicone rubber or hydroxyl-containing components to form a covalent crosslinking network; at the same time, the epoxy group or amino group (-NH2) contained therein can enhance the polar connection with the bonding substrate, thereby significantly improving the bonding effect.

[0024] The preparation method of the above-mentioned two-component silicone rubber coating includes the following preparation steps:

[0025] (1) The components are weighed according to the weight parts. Part of the vinyl silicone oil and hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 3-5 h, and then kneaded and stirred at 150-180°C and under vacuum conditions for 2-3 h to obtain a base glue. The base glue, catalyst, hydrogen-containing MQ silicone resin, adhesion promoter 1, and the remaining vinyl silicone oil are added to a power mixer, and stirred and degassed under vacuum at room temperature to obtain component A with a viscosity of 180-270 mPa·s;

[0026] (2) The components are weighed by weight parts, the vinyl silicone oil and the hydrogen silane modified reinforcing filler are kneaded and stirred at normal temperature and pressure for 3-5 hours, then are kneaded and stirred at 150-180℃ and under vacuum condition for 2-3 hours to obtain a base glue, which is cooled to room temperature, then the base glue, the hydrogen-terminated silicone oil crosslinking agent, the hydrogen-containing MQ silicone resin, the inhibitor and the tackifier 2 are added into a dynamic mixer, and are stirred and defoamed under vacuum condition at room temperature to obtain the component B with a viscosity of 200-300 million mPa·s.

[0027] The application of the two-component silicone rubber coating as a coating layer of an airbag.

[0028] Further, the application method is that the component A and the component B are uniformly mixed at room temperature, are coated on the surface of an airbag substrate, and then are subjected to a heating and curing treatment to obtain an airbag coating layer.

[0029] Further preferably, in the application method, the weight ratio of the mixture of the component A and the component B is 1:1.

[0030] Further preferably, in the application method, the temperature of the heating and curing treatment is 160-180℃, and the time is 1-2 minutes.

[0031] Compared with the prior art, the application has the following beneficial effects:

[0032] (1) The two-component silicone rubber coating of the application uses the hydrogen silane modified reinforcing filler, and uses the specific hydrogen-containing MQ silicone resin for synergistic reinforcement, and uses the hydrogen-terminated silicone oil crosslinking agent, utilizes the high and low density double crosslinking network formed by the hydrogen silane modified reinforcing filler and the hydrogen-terminated silicone oil crosslinking agent, and the obtained glue has the advantages of high strength and high elongation. In addition, the use of the hydrogen silane modified reinforcing filler and the use of the hydrogen-containing MQ silicone resin with a lower molecular weight for synergistic reinforcement can avoid the problem of too high viscosity of the glue caused by the use of high content and high specific surface area fumed silica reinforcing filler, and improve the easy coating property of the glue.

[0033] (2) The application can significantly improve the adhesion of the glue to the airbag substrate by adding the specific tackifier 1 and the tackifier 2 in the two-component silicone rubber coating, and at the same time, does not affect the stability and easy coating property of the glue.

[0034] (3) The operation performance, adhesion performance, tensile performance and tear performance of the automobile airbag coating material of the application are close to those of the imported product, and the cost is low, the preparation method is simple, and the use is easy. DETAILED DESCRIPTION

[0035] The application will be further described in detail below in combination with examples, but the embodiments of the application are not limited thereto.

[0036] Example 1

[0037] A two-component silicone rubber coating, comprising component A and component B, the component A comprising ingredients in the following weight proportions:

[0038] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 25000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 200 m 2 / g, surface-modified with 2.5 wt% trimethoxysilane): 18 parts, hydrogen-containing 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 5000 ppm): 0.2 parts, adhesion promoter 1 (isopropyl titanate): 2 parts.

[0039] The component B comprises ingredients in the following weight proportions:

[0040] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 25000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 200 m 2 / g, surface-modified with 2.5 wt% trimethoxysilane): 18 parts, hydrogen-containing MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, crosslinking agent (end-hydrogen silicone oil with a weight average molecular weight of 1500): 8 parts, inhibitor (ethynylcyclohexanol): 0.06 parts, adhesion promoter 2 (γ-glycidoxypropyltrimethoxysilane): 2 parts.

[0041] The two-component silicone rubber coating of the present embodiment is prepared by the following method:

[0042] (1) The components are weighed in parts by weight. 40 parts of vinyl silicone oil and 18 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 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 are added to a dynamic mixer, and stirred and degassed under vacuum at room temperature for 1 h to obtain component A. The viscosity of the obtained component A is 180000 mPa·s.

[0043] (2) The components are weighed in parts by weight. 65 parts of vinyl silicone oil and 18 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 8 parts of crosslinking agent, 5 parts of hydrogen-containing MQ silicone resin, 2 parts of γ-glycidoxypropyltrimethoxysilane, and 0.06 parts of inhibitor are added to a dynamic mixer, and stirred and degassed under vacuum at room temperature for 1 h to obtain component B. The viscosity of the obtained component B is 200000 mPa·s.

[0044] Example 2

[0045] A two-component silicone rubber coating, comprising Component A and Component B, wherein the Component A comprises the following ingredients in parts by weight:

[0046] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 35000): 60 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 250 m 2 / g, surface-modified by 3.5 wt% triethoxysilane): 15 parts, hydrogen-containing 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 5000 ppm): 0.1 part, adhesion promoter 1 (zirconium tetraacetylacetonate): 2 parts.

[0047] The Component B comprises the following ingredients in parts by weight:

[0048] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 35000): 60 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 250 m 2 / g, surface-modified by 3.5 wt% triethoxysilane): 15 parts, crosslinking agent (end-hydrogen silicone oil with a weight average molecular weight of 3000): 5 parts, inhibitor (tetramethyltetra-vinylcyclotetrasiloxane): 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 (glycidoxypropyltrimethoxysilane): 2 parts.

[0049] The two-component silicone rubber coating of the present example is prepared by the following method:

[0050] (1) The components are weighed in parts by weight. 35 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 3 h, and then kneaded and stirred at 170°C and under vacuum for 2 h to obtain a base glue. The base glue is cooled to room temperature. The base glue, 0.1 part of catalyst, 5 parts of hydrogen-containing MQ silicone resin, 2 parts of zirconium tetraacetylacetonate, and 25 parts of vinyl silicone oil are added to a dynamic mixer, and stirred and degassed under vacuum at room temperature for 1 h to obtain Component A. The viscosity of the obtained Component A is 190000 mPa·s.

[0051] (2) The components are weighed by parts by weight. 60 parts of vinyl silicone oil and 15 parts of hydrogen silane modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 3 hours, and then kneaded and stirred at 170°C and under vacuum for 2 hours to obtain a base glue. The base glue is cooled to room temperature. Then, 5 parts of crosslinking agent, 0.05 parts of inhibitor, 5 parts of hydrogen-containing MQ silicone resin, and 2 parts of epoxy propoxy propyl methyl dimethoxy silane are added into a dynamic mixer and stirred and degassed under vacuum at room temperature for 1 hour to obtain component B. The viscosity of the obtained component B is 210000 mPa·s.

[0052] Example 3

[0053] A two-component silicone rubber coating includes component A and component B. The component A includes the following components in parts by weight:

[0054] vinyl silicone oil (end vinyl silicone oil with a weight average molecular weight of 52000): 70 parts, hydrogen silane modified reinforcing filler (fumed silica with a specific surface area of 300 m 2 / g, which is surface modified by 1.5wt% trimethoxy hydrogen silane): 20 parts, hydrogen-containing MQ silicone resin (M / Q value is 1.2, molecular weight is 2000, hydrogen content is 0.5%): 5 parts, catalyst (chloroplatinic acid solution with a platinum content of 5000ppm): 0.3 parts, tackifier 1 (n-butyl titanate): 3 parts.

[0055] The component B includes the following components in parts by weight:

[0056] vinyl silicone oil (end vinyl silicone oil with a weight average molecular weight of 52000): 70 parts, hydrogen silane modified reinforcing filler (fumed silica with a specific surface area of 300 m 2 / g, which is surface modified by 1.5wt% trimethoxy hydrogen silane): 20 parts, crosslinking agent (end hydrogen silicone oil with a weight average molecular weight of 1500): 10 parts, inhibitor (tetramethyl tetra-vinyl cyclo tetra siloxane): 0.1 parts, hydrogen-containing MQ silicone resin (M / Q value is 1.2, molecular weight is 2000, hydrogen content is 0.5%): 5 parts, tackifier 2 (γ-aminopropyl triethoxy silane): 3 parts.

[0057] The two-component silicone rubber coating of the present example is prepared by the following method:

[0058] (1) The components are weighed by parts by weight. 45 parts of vinyl silicone oil and 20 parts of hydrogen silane modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 5 hours, and then kneaded and stirred at 160°C and under vacuum for 3 hours to obtain a base glue. The base glue is cooled to room temperature. Then, 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 are added into a dynamic mixer and stirred and degassed under vacuum at room temperature for 1 hour to obtain component A. The viscosity of the obtained component A is 220000 mPa·s.

[0059] (2) The components were weighed by parts by weight. 70 parts of vinyl silicone oil was kneaded and stirred with 20 parts of hydrogen silane modified reinforcing filler at room temperature and normal pressure for 5 h, and then was kneaded and stirred at 160°C under vacuum for 3 h to obtain a base glue. The base glue was reduced to room temperature, and then 10 parts of crosslinking agent, 0.1 part of inhibitor, 5 parts of hydrogen-containing MQ silicone resin and 3 parts of γ-aminopropyl triethoxysilane were added into a dynamic mixer, and stirred and defoamed under vacuum at room temperature for 1 h to obtain component B. The viscosity of the obtained component B was 235000 mPa·s.

[0060] Example 4

[0061] A two-component silicone rubber coating, comprising component A and component B, wherein the component A comprises the following components in parts by weight:

[0062] vinyl silicone oil (end-vinyl silicone oil with weight average molecular weight of 31000): 65 parts, hydrogen silane modified reinforcing filler (fumed silica with specific surface area of 350 m 2 / g, surface modified by 1.0 wt% trimethoxysilane): 18 parts, hydrogen-containing 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 platinum content of 5000 ppm): 0.2 parts, tackifier 1 (titanium isooctoate): 2 parts.

[0063] The component B comprises the following components in parts by weight:

[0064] vinyl silicone oil (end-vinyl silicone oil with weight average molecular weight of 31000): 65 parts, hydrogen silane modified reinforcing filler (fumed silica with specific surface area of 350 m 2 / g, surface modified by 1.0 wt% trimethoxysilane): 18 parts, hydrogen-containing MQ silicone resin (M / Q value of 1.0, molecular weight of 3000, hydrogen content of 0.25%): 5 parts, crosslinking agent (end-hydrogen silicone oil with weight average molecular weight of 1000): 8 parts, inhibitor (ethynylcyclohexanol): 0.06 parts, tackifier 2 (γ-glycidoxypropyl triethoxysilane): 2 parts.

[0065] The preparation method of the two-component silicone rubber coating of the present example is the same as that of example 1. The viscosity of the obtained component A was 250000 mPa·s. The viscosity of the obtained component B was 270000 mPa·s.

[0066] Example 5

[0067] A two-component silicone rubber coating, comprising component A and component B, wherein the component A comprises the following components in parts by weight:

[0068] Vinyl silicone oil (end-vinyl silicone oil with weight average molecular weight of 15000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with specific surface area of 400 m 2 / g, surface-modified with 0.5 wt% trimethoxysilane): 16 parts, hydrogen-containing 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 platinum content of 5000 ppm): 0.2 parts, adhesion promoter 1 (zirconium isooctoate): 3 parts.

[0069] The component B comprises the following ingredients by weight parts:

[0070] Vinyl silicone oil (end-vinyl silicone oil with weight average molecular weight of 15000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with specific surface area of 400 m 2 / g, surface-modified with 0.5 wt% trimethoxysilane): 16 parts, hydrogen-containing MQ silicone resin (M / Q value of 0.8, molecular weight of 4000, hydrogen content of 0.1%): 8 parts, crosslinking agent (end-hydrogen silicone oil with weight average molecular weight of 3800): 8 parts, inhibitor (ethynylcyclohexanol): 0.06 parts, adhesion promoter 2 (side-chain epoxy-modified polydimethylsiloxane, commercially available, epoxy content of 4.5 wt%, weight average molecular weight of 8000): 1 part.

[0071] The two-component silicone rubber coating of the present example is prepared by the following method:

[0072] (1) The components are weighed by weight parts. 40 parts of vinyl silicone oil and 16 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 0.2 parts of catalyst, 8 parts of hydrogen-containing MQ silicone resin, 3 parts of zirconium isooctoate and 25 parts of vinyl silicone oil are added into a dynamic mixer, and stirred and defoamed under vacuum at room temperature for 1 h to obtain component A. The viscosity of the obtained component A is 270000 mPa·s.

[0073] (2) The components are weighed by weight parts. 65 parts of vinyl silicone oil and 16 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 8 parts of crosslinking agent, 8 parts of hydrogen-containing MQ silicone resin, 1 part of side-chain epoxy-modified polydimethylsiloxane and 0.06 parts of inhibitor are added into a dynamic mixer, and stirred and defoamed under vacuum at room temperature for 1 h to obtain component B. The viscosity of the obtained component B is 300000 mPa·s.

[0074] Example 6

[0075] A two-component silicone rubber coating, comprising component A and component B, the component A comprising ingredients in the following weight proportions:

[0076] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 45000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 300 m 2 / g, surface-modified with 5 wt% triethoxysilane): 15 parts, hydrogen-containing 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 5000 ppm): 0.2 parts, tackifier 1 (tetraisopropyl zirconium): 1 part.

[0077] The component B comprises ingredients in the following weight proportions:

[0078] vinyl silicone oil (end-vinyl silicone oil with a weight average molecular weight of 45000): 65 parts, hydrogen-containing silane-modified reinforcing filler (fumed silica with a specific surface area of 300 m 2 / g, surface-modified with 5 wt% triethoxysilane): 15 parts, hydrogen-containing MQ silicone resin (M / Q value of 1.2, molecular weight of 2000, hydrogen content of 0.5%): 10 parts, crosslinking agent (end-hydrogen silicone oil with a weight average molecular weight of 800): 8 parts, inhibitor (ethynylcyclohexanol): 0.06 parts, tackifier 2 (end-epoxy-modified polydimethylsiloxane, commercially available, epoxy content of 2.1 wt%, weight average molecular weight of 4000): 3 parts.

[0079] The two-component silicone rubber coating of the present embodiment is prepared by the following method:

[0080] (1) The components are weighed in parts by weight. 40 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 0.2 parts of catalyst, 10 parts of hydrogen-containing MQ silicone resin, 1 part of tetraisopropyl zirconium, and 25 parts of vinyl silicone oil are added to a dynamic mixer, and stirred and degassed under vacuum at room temperature for 1 h to obtain component A. The viscosity of the obtained component A is 220000 mPa·s.

[0081] (2) The components are weighed in parts by weight. 65 parts of vinyl silicone oil and 15 parts of hydrogen-containing silane-modified reinforcing filler are kneaded and stirred at room temperature and normal pressure for 4 h, and then kneaded and stirred at 180°C and under vacuum for 2.5 h to obtain a base glue. The base glue is cooled to room temperature, and then 8 parts of crosslinking agent, 10 parts of hydrogen-containing MQ silicone resin, 3 parts of end-epoxy-modified polydimethylsiloxane, and 0.06 parts of inhibitor are added to a dynamic mixer, and stirred and degassed under vacuum at room temperature for 1 h to obtain component B. The viscosity of the obtained component B is 240000 mPa·s.

[0082] Comparative Example 1

[0083] A two-component silicone rubber coating, compared with Example 1, the unmodified reinforcing filler (specific surface area of 200 m 2 / g fumed silica) was used instead of the hydrogen-containing silane-modified reinforcing filler in Component A and Component B, and the rest was the same.

[0084] Comparative Example 2

[0085] A two-component silicone rubber coating, compared with Example 1, no hydrogen-containing MQ silicone resin was added in Component A and Component B, and the amount of hydrogen-containing silane-modified reinforcing filler was increased to 23 parts, and the rest was the same.

[0086] Comparative Example 3

[0087] A two-component silicone rubber coating, compared with Example 1, the crosslinking agent in Component B was a side-chain hydrogen-containing silicone oil with a weight average molecular weight of 1500, and the rest was the same.

[0088] Comparative Example 4

[0089] A two-component silicone rubber coating, compared with Example 1, no tackifier 1 was added in Component A, and the content of tackifier 2 was increased to 4 parts, and the rest was the same.

[0090] Comparative Example 5

[0091] A two-component silicone rubber coating, compared with Example 1, no tackifier 2 was added in Component B, and the content of tackifier 1 was increased to 4 parts, and the rest was the same.

[0092] The two-component silicone rubber coating obtained in the above examples and comparative examples was applied as a coating for a safety airbag, and the specific application method was as follows: Component A and Component B were mixed uniformly at a weight ratio of 1:1 at room temperature, then coated on the surface of a safety airbag substrate (PET), and then heated to 160-180°C for curing treatment for 2 min to obtain a safety airbag coating.

[0093] The adhesion, tensile and tear properties of the two-component silicone rubber coating obtained in the above examples and comparative examples were tested, the tensile strength and elongation were tested according to GB / T 528-2009, the tear strength was tested according to GB / T 529-2008, and the peel force was tested according to GB / T 2792-2014, and the results are shown in Table 1 below:

[0094] Table 1 Test Results

[0095] Test item Viscosity (mPa.s) Tensile strength (MPa) Tear strength (kN / m) Elongation at break (%) Peeling 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

[0096] From the comparison results of Comparative Example 1 and Example 1, it can be seen that the mechanical properties of the silicone rubber coating can be significantly improved by using the hydrogen-containing silane modified reinforcing filler compared with the unmodified reinforcing filler, because the mixing and dispersion effect of the reinforcing filler in the base rubber can be enhanced by the surface modification with the hydrogen-containing silane, and a high-density crosslinking network can be formed between the vinyl silicone oil and the hydrogen-containing silane during the subsequent curing process, thereby significantly improving the reinforcing effect. In addition, the viscosity of the rubber compound can be significantly reduced by using the hydrogen-containing silane modified reinforcing filler, thereby improving the coatability of the rubber compound, because the surface polarity of SiO2 can be reduced by the surface modification with the hydrogen-containing silane, thereby reducing the viscosity of the mixed rubber compound.

[0097] From the comparison results of Comparative Example 2 and Example 1, it can be seen that the mechanical properties of the silicone rubber coating can be significantly improved by using the low molecular weight hydrogen-containing MQ silicone resin for synergistic reinforcement, and the viscosity of the rubber compound can be reduced to some extent to ensure good draw coating performance. The strength of the silicone rubber is mainly affected by the molecular weight of the silicone oil, the proportion of the reinforcing filler, and the specific surface area of the filler (generally, the larger the specific surface area, the better the reinforcing property, but the higher the viscosity of the rubber compound). However, the strength of the silicone rubber can be improved by using high molecular weight silicone oil, high proportion of reinforcing filler, and high specific surface area of the reinforcing filler, but the viscosity of the rubber compound is too high to affect the draw coating performance. The low molecular weight hydrogen-containing MQ silicone resin can form a high-density crosslinking network with the vinyl silicone oil during the subsequent curing process, and has a relatively low viscosity before curing, thereby playing a synergistic reinforcing role while improving the draw coating performance of the rubber compound.

[0098] From the comparison results of Comparative Example 3 and Example 1, it can be seen that the flexibility of the silicone rubber coating can be significantly reduced by using the side-chain hydrogen-containing silicone oil as the crosslinking agent, because the overall crosslinking density of the cured silicone rubber coating is too large when the side-chain hydrogen-containing silicone oil is used as the crosslinking agent. However, the silicone rubber coating obtained by using the end-hydrogen silicone oil crosslinking agent in combination with the hydrogen-containing silane modified reinforcing filler and the hydrogen-containing MQ silicone resin has the advantages of high strength and high elongation, because of the formation of a high and low density dual crosslinking network between the end-hydrogen silicone oil and the vinyl silicone oil.

[0099] From the comparison results of Comparative Examples 4 and 5 and Example 1, it can be seen that the adhesion promoter effect of the product can be significantly improved by using Adhesion Promoter 1, and the main adhesion effect can be achieved by using Adhesion Promoter 2, and the adhesion of the silicone rubber to the substrate can be significantly improved by using the two adhesion promoters together.

[0100] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods, and shall be included in the protection scope of the present application.

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; 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; In the components A and B, the hydrogen-containing silane-modified reinforcing filler is fumed silica surface-modified with trimethoxyhydrogensilane or triethoxyhydrogensilane, 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 mass content of 0.1-0.5%.

2. A two-component silicone rubber coating according to claim 1, 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.

3. 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.

4. 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.

5. The method for preparing a two-component silicone rubber coating according to any one of claims 1 to 4, 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.

6. Use of a two-component silicone rubber coating according to any one of claims 1 to 4 as an airbag coating, characterized in that: The application method is: mix component A and component B evenly at room temperature, apply them on the surface of the airbag substrate, and then heat and cure them to obtain the airbag coating.

7. The use according to claim 6, 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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