High-strength, low-density and high-temperature-resistant organic silicon pouring sealant as well as preparation method and application thereof

Abstract

The invention discloses a high-strength, low-density and high-temperature-resistant organic silicon pouring sealant and a preparation method and application thereof.The organic silicon pouring sealant comprises a component A and a component B. The component A comprises vinyl silicone oil, silicon resin, low-density powder, high-temperature-resistant filler, cardanol substances and auxiliaries; the component B is prepared from phenyl silicone oil, optional pigment, low-density powder, high-temperature-resistant filler, cardanol substances, hydrogen-containing silicone oil, an inhibitor, a catalyst and an auxiliary. The pouring sealant solves the problems that low-density powder easily floats upwards and is layered in the components A and B of the pouring sealant, and the low-density pouring sealant is low in strength, and the pouring sealant which is homogeneous, high in strength, low in density and resistant to high temperature is provided.

Description

Technical Field

[0001] The present invention belongs to the field of potting adhesives, and particularly relates to a high-temperature resistant silicone potting adhesive with low density and high strength that can be continuously used under high-temperature conditions (above 250 °C), and a preparation method and application thereof. Background Art

[0002] Silicone potting adhesives are mainly used for fixing and potting electronic components in high-temperature environments, and can also be used for potting and fixing power batteries. New energy vehicles have become the trend of future vehicle development. The research and development of vehicle lightweighting is the key to saving electric energy and increasing the cruising range. Among them, the amount of adhesive used in new energy vehicles is 25 - 30 KG / vehicle, and potting adhesives are used in many components, such as power batteries, air-conditioning PTC heaters, motors, vehicle chargers, transformers, sensors, etc. Developing lightweight, heat-conducting, flame-retardant, and high-temperature resistant potting adhesives has always been a key point in new energy vehicles. Due to the properties of silicone such as insulation, flame retardancy, high temperature resistance, and aging resistance, it has gradually been applied to the field of new energy battery potting adhesives. Its thermal conductivity usually requires adding a large amount of fillers to the silicone potting adhesive, resulting in a general density of the rubber compound greater than 1.5 g / cm 3 , and after potting it into automotive electronic components, the weight gain of the system is relatively obvious. In order to adapt to the development trend of lightweighting and enable electronic components to have a higher energy density, it is usually necessary to develop potting adhesives with low density. The preparation of low-density potting adhesives usually uses hollow fillers, such as hollow glass microspheres, hollow coal cinder micro-powders, hollow silica micro-powders, etc. However, hollow fillers are prone to floating and stratifying during storage, and the strength of the potting adhesive is relatively low.

[0003] Under certain specific conditions, there are high requirements for the high-temperature resistance performance of potting adhesives. In the prior art, the ordinary high-temperature resistant silicone produced cannot withstand the high temperature above 200 °C of engine sealing components and the instantaneous high temperature generated during ignition for a long time, the elastic recovery is not good enough, the elasticity decreases at low temperatures, and elastic fatigue is prone to occur during long-term use, affecting the sealing performance. Especially, the maximum temperature of the practical PTC heating material is 300 °C. Therefore, ordinary silicone potting adhesives far from meet the requirements. Ordinary potting adhesives have deficiencies in high-temperature resistance performance and mechanical properties, and there is an obvious decay under long-term high-temperature conditions, resulting in the life attenuation of PTC heaters. Moreover, the currently used PTC high-temperature resistant adhesives all have a relatively high density, which is also not conducive to the realization of vehicle lightweighting. Summary of the Invention

[0004] In view of the problems existing in the prior art, it is still necessary to develop a high-strength, low-density, high-temperature resistant silicone potting adhesive, which can avoid the floating and stratification of low-density powders on the basis of meeting low density and high strength, has a temperature resistance of up to 300 °C, and can remain crack-free and non-detachable under long-term high temperatures.

[0005] Another object of the present invention is to provide a method for preparing such a high-strength, low-density, high-temperature resistant silicone potting adhesive.

[0006] Still another object of the present invention is to provide the application of such a high-strength, low-density, high-temperature resistant silicone potting adhesive.

[0007] To achieve the above-mentioned invention objects, the present invention adopts the following technical solutions:

[0008] A high-strength, low-density, high-temperature resistant silicone potting adhesive, comprising component A and component B, wherein the mass ratio of component A to component B is 10 to 1:1, such as 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, etc.;

[0009] By weight, the component A comprises the following components:

[0010] Vinyl silicone oil 10 - 50 parts, such as 10, 15, 20, 25, 30, 35, 40, 45, 50 parts, etc., preferably 20 - 40 parts;

[0011] Silicone resin 10 - 60 parts, such as 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 parts, etc., preferably 20 - 50 parts;

[0012] Low-density powder 2 - 70 parts, such as 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 parts, etc., preferably 10 - 60 parts;

[0013] High-temperature resistant filler 0.5 - 8 parts, such as 1, 2, 3, 4, 5, 6, 7, 8 parts, etc., preferably 1 - 5 parts;

[0014] Cardanol-based substance 1 - 15 parts, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5 - 10 parts;

[0015] Auxiliary agent 0.1 - 10 parts, such as 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts, etc., preferably 0.2 - 6 parts;

[0016] By weight, the component B comprises the following components:

[0017] Phenyl silicone oil 5 - 40 parts, such as 5, 10, 15, 20, 25, 30, 35, 40 parts, etc., preferably 10 - 25 parts;

[0018] Pigment 0 - 5 parts, such as 0, 1, 2, 3, 4, 5 parts, etc., preferably 0.5 - 3 parts;

[0019] 2 to 80 parts of low-density powder, such as 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 parts, etc., preferably 25 to 70 parts;

[0020] 0.5 to 8 parts of high-temperature resistant filler, such as 1, 2, 3, 4, 5, 6, 7, 8 parts, etc., preferably 1 to 5 parts;

[0021] 1 to 15 parts of cardanol substances, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5 to 10 parts;

[0022] 0.07 to 7 parts of additives, such as 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7 parts, etc., preferably 0.3 to 3 parts;

[0023] 2 to 30 parts of hydrogen-containing silicone oil, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30 parts, etc., preferably 10 to 20 parts.

[0024] In some specific embodiments, the vinyl silicone oil includes at least any one of end vinyl polydimethylsiloxane (Vi-PDMS) with different viscosities and end vinyl polymethylvinylsiloxane (Vi-PMVS) with different viscosities; preferably, the viscosity of the vinyl silicone oil at 25 °C is 10 to 110000 mPa·s, such as 50 mPa·s, 100 mPa·s, 500 mPa·s, 1000 mPa·s, 5000 mPa·s, 10000 mPa·s, 50000 mPa·s, 80000 mPa·s, 100000 mPa·s, and the vinyl content is 0.01 to 5 wt%, such as 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, etc. One or several products with different viscosities and vinyl contents can be selected according to needs.

[0025] In some specific embodiments, the silicone resin includes at least any one of methylphenyl silicone resin, methyl silicone resin, low phenyl methyl silicone resin, epoxy modified silicone resin, benzyl transparent silicone resin, methyl transparent silicone resin, mica bonding silicone resin, polymethyl silicone resin, amino silicone resin, fluorosilicone resin, silicone-epoxy resin, silicone polyester resin, solvent-resistant silicone resin, methyl MQ silicone resin, vinyl MQ silicone resin, etc. Preferably, it includes one or more of methylphenyl silicone resin, low phenyl methyl silicone resin, benzyl transparent silicone resin, methyl MQ silicone resin, vinyl MQ silicone resin, etc.

[0026] In some specific embodiments, the hydrogen-containing silicone oil includes at least any one of end-side hydrogen-containing silicone oil, side hydrogen-containing silicone oil, end hydrogen-containing silicone oil, mono-end hydrogen-containing silicone oil, etc.; preferably, the viscosity of the hydrogen-containing silicone oil at 25 °C is 10 to 1000 mPa·s, such as 10 mPa·s, 50 mPa·s, 100 mPa·s, 500 mPa·s, 1000 mPa·s, etc., and the hydrogen content is 0.01 to 2 wt%, such as 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, etc. One or more products with different viscosities and hydrogen contents can be selected according to needs.

[0027] In some specific embodiments, the low-density powder includes at least any one of hollow glass microspheres, hollow alumina, zinc oxide-coated hollow glass microspheres, hollow ceramic microspheres, hollow silica, montmorillonite, etc.; preferably, it is selected from one or more of hollow alumina, zinc oxide-coated hollow glass microspheres, hollow silica, hollow ceramic microspheres.

[0028] In some specific embodiments, the high-temperature resistant filler includes at least any one of cerium oxide, iron tetroxide, fumed silica, boron nitride, magnesium oxide, aluminum oxide, mica, corundum, silicon, carbon, copper oxide, iron powder, manganese dioxide, etc.; preferably, it is selected from one or more of cerium oxide, iron tetroxide, fumed silica, boron nitride, magnesium oxide, aluminum oxide, etc.

[0029] In some specific embodiments, the phenyl silicone oil includes at least any one of methylphenyl silicone oil, diphenyl silicone oil, perbenzene, tribenzene, dibenzene, phenyl hydrogen-containing silicone oil, phenyl vinyl silicone oil, etc.; preferably, it is selected from one or more of methylphenyl silicone oil, diphenyl silicone oil, phenyl hydrogen-containing silicone oil, etc.

[0030] In some specific embodiments, the cardanol substances include at least any one of cardanol or cardanol derivatives; preferably, one or more selected from cardanol, amino-terminated modified cardanol, epoxy resin modified cardanol, polyol resin modified cardanol, benzoxazine modified cardanol, phenolic resin modified cardanol, polyester modified cardanol.

[0031] In some specific embodiments, the pigments include at least any one of carbon black, oxides, chromates, silicates, borates, molybdates, vanadates, hydroxides, metals, etc.; preferably, one or more selected from carbon black, oxides, hydroxides, silicates, borates, ferrocyanates. Among them, the metals are, for example, aluminum powder, silver powder, zinc powder, gold powder, copper powder, etc., the oxides are, for example, iron oxide, chromium oxide, copper oxide, titanium dioxide, etc., the chromates are, for example, lead chromate, chromium sesquioxide, etc., the silicates are, for example, quartz, feldspar, strontium silicate, calcium silicate, etc., the borates are, for example, barium metaborate, etc., the molybdates are, for example, zinc molybdate, etc., the vanadates are, for example, bismuth vanadate, indium vanadate, etc., the hydroxides are, for example, iron hydroxide, zinc hydroxide, etc. These pigments are all conventional selections in the art and there is no special limitation in the present invention.

[0032] In some specific embodiments, the additives are selected from at least any one of tackifiers, antioxidants, inhibitors, catalysts. Those skilled in the art can understand that other additives, such as fungicides, leveling agents, etc., can also be added according to the product performance and processing needs. These are all conventional means in the art and should also be within the protection scope of the present invention.

[0033] In some specific embodiments, the tackifier is one or more of epoxy group silane coupling agents, amino group silane coupling agents, mercapto group silane coupling agents; preferably, one or more selected from 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane (KH560), 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, etc.

[0034] In some specific embodiments, the antioxidant is one or more of tea polyphenols (TP), tocopherol, flavonoids, butylated hydroxyanisole (BHA), dibutylhydroxytoluene (BHT), tert-butylhydroquinone (TBHQ); preferably, it is selected from one or several of tea polyphenols (TP), flavonoids, butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), etc.

[0035] In some specific embodiments, the inhibitor includes: 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclohexanol, 3-phenyl-1-butyn-3-ol, alkynyloxy silane, alkynyloxy-containing polysiloxane, methyl vinyl cyclotetrasiloxane, polyvinyl polysiloxane, amide compound, monoethyl maleate, monoallyl maleate, mono-2-ethylhexyl maleate, diallyl maleate, etc.; preferably, it is selected from one or several of 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclohexanol, 3-phenyl-1-butyn-3-ol, monoethyl maleate, monoallyl maleate, mono-2-ethylhexyl maleate, diallyl maleate, etc.

[0036] In some specific embodiments, the catalyst includes: one or more of platinum-vinylsiloxane complex, octanol-modified chloroplatinic acid catalyst, ethanol-modified chloroplatinic acid catalyst, bis(alkynyl)bis(triphenylphosphine)platinum complex, bis(alkynyl)(cyclodienyl)platinum complex, etc.; preferably, it is selected from one or more of chloroplatinic acid tetramethyltetravinylcyclotetrasiloxane complex, platinum-isopropanol complex, platinum-triene complex, platinum-divinyltetramethyldisiloxane complex, platinum-(N-heterocyclic carbene) complex.

[0037] In a preferred embodiment, the two-component silicone potting adhesive provided by the present invention

[0038] wherein the component A includes the following components in parts by weight:

[0039] Vinyl silicone oil 10-50 parts, such as 10, 15, 20, 25, 30, 35, 40, 45, 50 parts, etc., preferably 20-40 parts;

[0040] Silicone resin 10-60 parts, such as 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 parts, etc., preferably 20-50 parts;

[0041] Hollow alumina 1-35 parts, such as 5, 10, 15, 20, 25, 30, 35 parts, etc., preferably 5-30 parts;

[0042] 1 - 35 parts of zinc oxide - coated hollow glass microspheres, such as 5, 10, 15, 20, 25, 30, 35 parts, etc., preferably 5 - 30 parts;

[0043] 0.5 - 8 parts of high - temperature resistant filler, such as 1, 2, 3, 4, 5, 6, 7, 8 parts, etc., preferably 1 - 5 parts;

[0044] 1 - 15 parts of cardanol - based substances, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5 - 10 parts;

[0045] 0.05 - 8 parts of tackifier, such as 1, 2, 3, 4, 5, 6, 7, 8 parts, etc., preferably 0.1 - 5 parts;

[0046] 0.05 parts - 2 parts of antioxidant, such as 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2 parts, etc., preferably 0.1 - 1 part;

[0047] Among them, component B includes the following components in parts by weight:

[0048] 5 - 30 parts of phenyl silicone oil, such as 5, 10, 15, 20, 25, 30 parts, etc., preferably 10 - 25 parts;

[0049] 0 - 5 parts of pigment, such as 1, 2, 3, 4, 5 parts, etc., preferably 0.5 - 3 parts;

[0050] 1 - 35 parts of hollow alumina, such as 5, 10, 15, 20, 25, 30, 35 parts, etc., preferably 5 - 30 parts;

[0051] 1 - 45 parts of zinc oxide - coated hollow glass microspheres, such as 5, 10, 15, 20, 25, 30, 35, 40, 45 parts, etc., preferably 20 - 40 parts;

[0052] 0.5 - 8 parts of high - temperature resistant filler, such as 1, 2, 3, 4, 5, 6, 7, 8 parts, etc., preferably 1 - 5 parts;

[0053] 1 - 15 parts of cardanol - based substances, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5 - 10 parts;

[0054] 0.05 - 3 parts of tackifier, such as 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3 parts, etc., preferably 0.1 - 1 part;

[0055] 1-15 parts of terminal hydrogen-containing silicone oil, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5-10 parts;

[0056] 1-15 parts of side hydrogen-containing silicone oil, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 parts, etc., preferably 5-10 parts;

[0057] 0.01-2 parts of inhibitor, such as 0.03, 0.05, 0.08, 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2 parts, etc., preferably 0.1-1 part;

[0058] 0.01-2 parts of catalyst, such as 0.03, 0.05, 0.08, 0.1, 0.3, 0.5, 0.8, 1, 1.1, 1.3, 1.5, 1.7, 1.8, 1.9, 2 parts, etc., preferably 0.1-1 part.

[0059] The present invention uses cardanol substances as surfactants, and the tackifier modifies the powder under certain conditions. The two work together to enhance and improve the overall compatibility of the rubber compound, and at the same time can reduce the viscosity of components A and B before curing; the solubilization effect on the powder effectively prevents the thermal conductive filler from floating and stratifying in the silicone potting adhesive, making the filler evenly dispersed in components A / B; the combination of low-density powders, especially hollow powders, as thermal conductive fillers is beneficial to reducing the density of the potting adhesive; the cardanol substances contain a benzene ring structure. During the curing process, the hydroxyl groups and double bonds in the cardanol substances can participate in the hydrosilylation reaction and improve the strength and high-temperature resistance of the potting adhesive, avoiding the situation of low mechanical strength and excessive local temperature.

[0060] On the other hand, a preparation method of a high-strength, low-density, high-temperature resistant silicone potting adhesive of the present invention includes the following steps:

[0061] 1) Preparation of component A: Add vinyl silicone oil, silicone resin, low-density powder, and high-temperature resistant filler into a kneading machine, stir under vacuum at 120-180°C for 1-3 hours. After the temperature drops to 50-80°C, add cardanol substances and tackifier, and react under vacuum for 1-3 hours; cool down to 20-40°C, then add antioxidant, and continue to stir for 10-30 minutes to obtain component A;

[0062] 2) Preparation of Component B: Add phenyl silicone oil, pigment, low-density powder, and high-temperature resistant filler into a kneading machine, stir under vacuum at 120 - 180 °C for 1 - 3 h. After the temperature drops to 50 - 80 °C, add cardanol substances and tackifier, and react under vacuum for 1 - 3 h; cool down to 20 - 40 °C, then add hydrogen-containing silicone oil, and continue stirring for 10 - 30 min; then add inhibitor and catalyst, and continue stirring for 10 - 30 min to obtain Component B;

[0063] 3) Preparation of potting adhesive: Mix Component A and Component B evenly according to the mass ratio of (10 - 1):1, then conduct vacuum degassing, and cure at 80 - 120 °C for 2 - 12 h to obtain a high-strength, low-density, high-temperature resistant silicone potting adhesive.

[0064] In a specific embodiment, the preparation method includes the following steps:

[0065] 1) Preparation of Component A: Add 20 - 40 parts of vinyl silicone oil, 20 - 50 parts of silicone resin, 5 - 30 parts of hollow alumina, 5 - 30 parts of zinc oxide-coated hollow glass microspheres, 1 - 5 parts of high-temperature resistant filler, etc. into a kneading machine, stir under vacuum at 120 to 180 °C for 1 to 3 h. After the temperature drops to 50 to 80 °C, add 5 - 10 parts of cardanol substances and 0.1 - 5 parts of tackifier, and react under vacuum for 1 to 3 h; cool down to 20 - 40 °C, then add 0.1 - 1 part of antioxidant, and continue stirring for 10 - 30 min to obtain Component A;

[0066] 2) Preparation of Component B: Add 10 - 25 parts of phenyl silicone oil, 0.5 - 3 parts of pigment, 5 - 30 parts of hollow alumina, 20 - 40 parts of zinc oxide-coated hollow glass microspheres, 1 - 5 parts of high-temperature resistant filler, etc. into a kneading machine, stir under vacuum at 120 to 180 °C for 1 to 3 h. After the temperature drops to 50 to 80 °C, add 5 - 10 parts of cardanol substances and 0.1 - 1 part of tackifier, and react under vacuum for 1 to 3 h; cool down to 20 - 40 °C, then add 5 - 10 parts of terminal hydrogen-containing silicone oil and 5 - 10 parts of side hydrogen-containing silicone oil, and continue stirring for 10 - 30 min; then add 0.1 part of inhibitor (ethynylcyclohexanol) and 0.5 part of catalyst (chloroplatinic acid tetramethyltetravinylcyclotetrasiloxane complex), and continue stirring for 10 - 30 min to obtain Component B;

[0067] 3) Preparation of potting adhesive: Mix Components A and B evenly according to the mass ratio of (10 - 1):1, then conduct vacuum degassing, and cure at 80 to 120 °C for 2 to 12 h to obtain the low-density, high-strength, high-temperature resistant silicone potting adhesive; preferably, mix Components A and B evenly according to the mass ratio of 10:1, conduct vacuum degassing, and cure at 80 °C for 1 h to obtain the potting adhesive.

[0068] In another aspect of the present invention, there is provided an application of the foregoing high-strength, low-density, high-temperature resistant silicone potting adhesive in the fixation and potting of electronic components or power batteries.

[0069] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0070] The A and B component glue liquids of the present invention have moderate viscosities, excellent defoaming performance and anti-stratification stability; the potting adhesive formed after the glue liquid is cured has a low density, good high-temperature resistance, uniform heat conduction performance, excellent tensile strength, elongation at break and bonding strength, good mechanical properties, strong applicability and good application effects.

[0071] By adding cardanol substances and tackifiers, the present invention achieves a surface modification effect on low-density powders, especially hollow powders, improves the compatibility of low-density powders, especially hollow powders, with silicone oil and silicone resin, avoids the floating and stratification of low-density powders, especially hollow powders, and enhances mechanical strengths such as tensile strength and shear strength; at the same time, by introducing low-density powders, especially hollow powders, the density of the colloid is greatly reduced, and the lightweight of the colloid material is realized on the premise of maintaining good mechanical strength; furthermore, by adding phenyl silicone oil, phenyl resin and cardanol substances, the high-temperature resistance of the colloid is improved, and its heat resistance can reach 300 °C, meeting the requirements for the components to continuously work under high-temperature conditions.

[0072] The silicone potting adhesive of the present invention is aged at 300 °C for 2000 h, and the colloid basically has no cracking or peeling phenomenon, and the heat resistance of the colloid is good, and it can maintain no cracking or peeling under long-term high temperature. Detailed Embodiments

[0073] The following further illustrates the present invention in conjunction with embodiments. The following examples are only for the illustration of the present invention and are not used to limit the scope of the present invention.

[0074] The main raw material sources used in the following examples are shown in the following table.

[0075]

[0076]

[0077] Among them, the main equipment is shown in the following table.

[0078]

[0079]

[0080] In the following examples, the main analysis and characterization methods are as follows:

[0081] 1) Tensile strength and elongation at break performance test

[0082] The tensile strength and elongation at break were tested using a CMT4202 universal material testing machine. The room temperature vulcanized foam silicone rubber products were conditioned in a standard environment for more than 16 h at a temperature of 23°C ± 2°C and a relative humidity of 50° ± 5%. The thickness of the specimen was 2 mm, and it was a dumbbell-shaped specimen. The sample preparation and testing were carried out in accordance with the national standard GB / TF6344-2008.

[0083] 2) Hardness test

[0084] The hardness of the potting adhesive material was tested using the industry standard HG / T2489-2007, and the instrument used was a Shore A durometer of model LX-C. The thickness of the specimen was 10 ± 0.5 mm. Specimens with a thickness less than 10 mm could be stacked together for testing, but it was necessary to ensure that the contact surface was smooth and flat.

[0085] 3) Shear strength test

[0086] The shear strength was tested using a CMT4202 universal material testing machine. The fully cured test samples to be tested were conditioned in a standard environment for more than 16 h at a temperature of 23°C ± 2°C and a relative humidity of 50° ± 5%. The shear aluminum sheets of the specimens were prepared and tested in accordance with the national standard GB / TF6344-2008.

[0087] Example 1

[0088] A component of the potting adhesive: 41 parts of phenyl vinyl silicone oil RH-510V-500, 25 parts of vinyl phenyl silicone resin RH-SP605, 5 parts of hollow alumina, 20 parts of zinc oxide-coated hollow glass microspheres, and 2 parts of cerium oxide were added to a kneading machine and stirred under vacuum at 130°C for 2 h. After the temperature dropped to 60°C, 6 parts of cardanol glycidyl ether and 0.65 part of silane coupling agent KH550 were added and reacted under vacuum for 1 h; the temperature was lowered to 35°C, and then 0.35 part of antioxidant 1010 was added and stirred for another 15 min to obtain the A component;

[0089] B component of the potting adhesive: 24.34 parts of phenyl methyl silicone oil DY-P201, 0.51 part of black paste, 15 parts of hollow alumina, 39 parts of zinc oxide-coated hollow glass microspheres, 2 parts of cerium oxide, etc. were added to a kneading machine and stirred under vacuum at 130°C for 2 h. After the temperature dropped to 60°C, 6 parts of cardanol glycidyl ether and 0.65 part of silane coupling agent KH550 were added and reacted under vacuum for 1 h; the temperature was lowered to 35°C, and then 5 parts of phenyl hydrogen silicone oil PH201 and 6.9 parts of side hydrogen-containing silicone oil RH-H86 were added and stirred for 15 min; then 0.1 part of inhibitor ethynyl cyclohexanol and 0.5 part of catalyst chloroplatinic acid tetramethyltetravinylcyclotetrasiloxane complex were added and stirred for another 15 min to obtain the B component;

[0090] Preparation of potting adhesive: Mix components A and B in a mass ratio of 10:1 evenly, then conduct vacuum degassing, and cure at 80 °C for 1 h to obtain the low-density high-temperature resistant potting adhesive.

[0091] Example 2

[0092] Component A of potting adhesive: Add 30 parts of phenyl vinyl silicone oil RH-510V-1000, 35 parts of vinyl phenyl silicone resin RH-SP606, 15 parts of hollow alumina, 8 parts of zinc oxide-coated hollow glass microspheres, and 3.5 parts of iron oxide into a kneader, and stir under vacuum at 170 °C for 1 h; after the temperature drops to 70 °C, add 7.84 parts of cardanol (3-pentadecylphenol) and 0.51 part of silane coupling agent KH570, and react under vacuum conditions for 2 h; cool down to 30 °C, add 0.15 part of antioxidant 1035, and continue to stir for 20 min to obtain component A;

[0093] Component B of potting adhesive: Add 40 parts of phenyl methyl silicone oil RH-510-500, 3 parts of black paste, 6 parts of hollow alumina, 21 parts of zinc oxide-coated hollow glass microspheres, and 3.3 parts of iron oxide into a kneader, and stir under vacuum at 170 °C for 1 h; after the temperature drops to 70 °C, add 8 parts of cardanol (3-pentadecylphenol) and 0.11 part of silane coupling agent KH570, and react under vacuum conditions for 2 h; cool down to 30 °C, then add 8 parts of terminal hydrogen-containing silicone oil RH-H518 and 9.1 parts of side hydrogen-containing silicone oil RH-H138, and stir for 30 min; then add 0.9 part of inhibitor diallyl maleate and 0.59 part of catalyst platinum-isopropanol complex, and stir for 20 min to obtain component B;

[0094] Preparation of potting adhesive: Mix components A and B in a mass ratio of 5:1 evenly, then conduct vacuum degassing, and cure at 120 °C for 30 min to obtain the low-density high-temperature resistant potting adhesive.

[0095] Example 3

[0096] Component A of potting adhesive: Add 20 parts of phenyl vinyl silicone oil RH-510V-5000, 31 parts of vinyl silicone resin S11H, 25 parts of hollow alumina, 4.52 parts of zinc oxide-coated hollow glass microspheres, and 4.5 parts of fumed silica into a kneader, and stir under vacuum at 150 °C for 1.5 h; after the temperature drops to 80 °C, add 9.5 parts of cardanol polyoxyethylene ether BGF-6 and 4.5 parts of silane coupling agent KH540, and react under vacuum conditions for 2.5 h; cool down to 40 °C, then add 0.98 part of antioxidant 168, and continue to stir for 30 min to obtain component A;

[0097] Component B of potting adhesive: Add 28 parts of phenylmethyl silicone oil RH-510-1000, 0.8 part of iron oxide, 25 parts of hollow alumina, 25 parts of zinc oxide-coated hollow glass microspheres, and 4.5 parts of fumed silica into a kneader, stir under vacuum at 150 °C for 1.5 h. After the temperature drops to 80 °C, add 9.5 parts of cardanol polyoxyethylene ether BGF-6 and 0.9 part of silane coupling agent KH540, and react under vacuum conditions for 2.5 h; cool down to 40 °C, then add 2 parts of hydrogen-terminated silicone oil RH LHC-1 and 3.5 parts of side hydrogen-containing silicone oil RH-H33, and stir for 30 min; then add 0.5 part of inhibitor 2-methyl-3-butyn-2-ol and 0.3 part of catalyst platinum-divinyltetramethyldisiloxane complex, and stir for 30 min to obtain Component B;

[0098] Preparation of potting adhesive: Mix Component A and Component B evenly according to a mass ratio of 2:1, then degas under vacuum, and cure at 100 °C for 1 h to obtain the low-density high-temperature resistant potting adhesive.

[0099] Comparative Example 1

[0100] Compared with Example 1, replace the cardanol glycidyl ether in Component A and Component B with dimethyl silicone oil (viscosity 1000 cp) in equal amounts. The other components are exactly the same.

[0101] Comparative Example 2

[0102] Compared with Example 2, replace the hollow alumina and zinc oxide-coated hollow glass microspheres in Component A and Component B with alumina and zinc oxide respectively in equal amounts. The other components are exactly the same.

[0103] Comparative Example 3

[0104] Compared with Example 3, replace the cardanol polyoxyethylene ether BGF-6 in Component A and Component B with dimethyl silicone oil (viscosity 1000 cp) in equal amounts. The other components are exactly the same.

[0105] <Sample Testing>

[0106] Compare and test the samples in Examples 1, 2, and 3 with Comparative Examples 1, 2, and 3 respectively. The test items include: curing time, high-temperature resistance at 300 °C, shear strength attached to the metal substrate, and tensile strength of the colloid. The test results are shown in the following table.

[0107]

[0108]

[0109] It can be clearly seen from the above table that a high-strength, low-density, high-temperature resistant silicone potting adhesive prepared by the present invention has good adhesion and high-temperature resistance. After curing, the density of the colloid is less than that of the colloids on the market. From the data of the curing time, it can be seen that the colloid cures very quickly at high temperatures and can meet the requirements of assembly line production operations; after heat curing, from the data of the tensile strength and shear strength, it can be seen that the bonding strength of the colloid can meet the requirements of bonding and fixing of PTC components and applications; from the 300 °C aging data, it can be seen that the colloid has good temperature resistance and can remain crack-free and non-detaching under long-term high temperatures. Therefore, a high-strength, low-density, high-temperature resistant silicone adhesive prepared by the present invention has good high-temperature resistance and good adhesion, meets the high-temperature requirements for bonding of PTC components, and can be used as a potting adhesive for power batteries.

[0110] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several deductions or equivalent replacements can be made without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A high-strength, low-density, high-temperature resistant silicone potting adhesive, characterized in that, It includes Component A and Component B, wherein the mass ratio of Component A to Component B is 10 to 1:1; By weight, Component A includes the following components: Vinyl silicone oil: 10 to 50 parts, preferably 20 to 40 parts; Silicone resin: 10 to 60 parts, preferably 20 to 50 parts; Low-density powder: 2 to 70 parts, preferably 10 to 60 parts; High-temperature resistant filler: 0.5 to 8 parts, preferably 1 to 5 parts; Cardanol substances: 1 to 15 parts, preferably 5 to 10 parts; Auxiliary agent: 0.1 to 10 parts, preferably 0.2 to 6 parts; By weight, Component B includes the following components: Phenyl silicone oil: 5 to 40 parts, preferably 10 to 25 parts; Pigment: 0 to 5 parts, preferably 0.5 to 3 parts; Low-density powder: 2 to 80 parts, preferably 25 to 70 parts; High-temperature resistant filler: 0.5 to 8 parts, preferably 1 to 5 parts; Cardanol substances: 1 to 15 parts, preferably 5 to 10 parts; Auxiliary agent: 0.07 to 7 parts, preferably 0.3 to 3 parts; Hydrogen-containing silicone oil: 2 to 30 parts, preferably 10 to 20 parts.

2. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The vinyl silicone oil is selected from at least one of terminal vinyl polydimethylsiloxane and terminal vinyl polymethylvinylsiloxane; preferably, the vinyl silicone oil has a viscosity of 10 to 110000 mPa·s at 25°C and a vinyl content of 0.01 to 5 wt%.

3. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The silicone resin is selected from at least one of methyl phenyl silicone resin, methyl silicone resin, low phenyl methyl silicone resin, epoxy modified silicone resin, benzyl transparent silicone resin, methyl transparent silicone resin, mica bonding silicone resin, polymethyl silicone resin, amino silicone resin, fluorosilicone resin, silicone-epoxy resin, silicone polyester resin, solvent-resistant silicone resin, methyl MQ silicone resin, vinyl MQ silicone resin; preferably, it is selected from one or more of methyl phenyl silicone resin, low phenyl methyl silicone resin, benzyl transparent silicone resin, methyl MQ silicone resin, and vinyl MQ silicone resin.

4. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The hydrogen-containing silicone oil is selected from at least one of terminal and side hydrogen-containing silicone oil, side hydrogen-containing silicone oil, terminal hydrogen-containing silicone oil, and single-terminal hydrogen-containing silicone oil; preferably, the hydrogen-containing silicone oil has a viscosity of 10 to 1000 mPa·s at 25°C and a hydrogen content of 0.01 to 2 wt%.

5. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The low-density powder is selected from at least one of hollow glass microspheres, hollow alumina, zinc oxide-coated hollow glass microspheres, hollow ceramic microspheres, hollow silica, and montmorillonite; preferably, it is selected from one or more of hollow alumina, zinc oxide-coated hollow glass microspheres, hollow silica, and hollow ceramic microspheres; and / or The high-temperature resistant filler is selected from at least one of cerium oxide, iron tetroxide, fumed silica, boron nitride, magnesium oxide, aluminum oxide, aluminum nitride, mica, corundum, silicon, carbon, copper oxide, iron powder, and manganese dioxide; preferably, it is selected from one or more of cerium oxide, iron tetroxide, fumed silica, boron nitride, magnesium oxide, and aluminum oxide.

6. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The phenyl silicone oil is selected from at least one of methyl phenyl silicone oil, diphenyl silicone oil, perbenzene, tribenzene, bisbenzene, phenyl hydrogen-containing silicone oil, and phenyl vinyl silicone oil; preferably, it is selected from one or more of methyl phenyl silicone oil, diphenyl silicone oil, and phenyl hydrogen-containing silicone oil.

7. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The cardanol-based substance is selected from at least one of cardanol or cardanol derivatives; preferably, it is selected from one or more of cardanol, amino-terminated modified cardanol, epoxy resin-modified cardanol, polyol resin-modified cardanol, benzoxazine-modified cardanol, phenolic resin-modified cardanol, and polyester-modified cardanol.

8. The high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 1, characterized in that, The pigment is selected from any one of carbon black, oxides, chromates, silicates, borates, molybdates, vanadates, hydroxides, and metals; preferably, it is selected from one or more of carbon black, oxides, hydroxides, silicates, borates, and ferrocyanates; and / or The auxiliary agent is selected from at least one of tackifiers, antioxidants, inhibitors, and catalysts; Preferably, the tackifier is selected from one or more of epoxy group silane coupling agents, amino group silane coupling agents, and mercapto group silane coupling agents; preferably, it is selected from one or more of 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane; and / or. The antioxidant is selected from at least one of tea polyphenols, tocopherols, flavonoids, butylated hydroxyanisole, dibutylhydroxytoluene, and tert-butylhydroquinone; preferably, it is selected from one or more of tea polyphenols, flavonoids, butylated hydroxyanisole, and tert-butylhydroquinone; and / or The inhibitor is selected from at least one of 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclohexanol, 3-phenyl-1-butyn-3-ol, alkynyloxy silane, alkynyloxy-containing polysiloxane, methyl vinyl cyclotetrasiloxane, polyvinyl polysiloxane, amide compound, monoethyl maleate, monoallyl maleate, mono-2-ethylhexyl maleate, diallyl maleate; preferably, selected from one or more of 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclohexanol, 3-phenyl-1-butyn-3-ol, monoethyl maleate, monoallyl maleate, mono-2-ethylhexyl maleate, diallyl maleate; and / or The catalyst is selected from at least one of platinum-vinylsiloxane complex, octanol-modified chloroplatinic acid catalyst, ethanol-modified chloroplatinic acid catalyst, bis(alkynyl)bis(triphenylphosphine)platinum complex, bis(alkynyl)(cyclodienyl)platinum complex; preferably, selected from one or more of chloroplatinic acid tetramethyltetravinylcyclotetrasiloxane complex, platinum-isopropanol complex, platinum-triene complex, platinum-divinyltetramethyldisiloxane complex, platinum-(N-heterocyclic carbene) complex.

9. The preparation method of the high-strength, low-density, high-temperature resistant silicone potting adhesive according to any one of claims 1 to 8, characterized in that, Comprising the following steps: 1) Preparation of component A: Add vinyl silicone oil, silicone resin, low-density powder, and high-temperature resistant filler into a kneader, stir under vacuum at 120-180°C for 1-3 h. After the temperature drops to 50-80°C, add cardanol substances and tackifier, and react under vacuum for 1-3 h; cool down to 20-40°C, then add antioxidant, and continue stirring for 10-30 min to obtain component A; 2) Preparation of component B: Add phenyl silicone oil, pigment, low-density powder, and high-temperature resistant filler into a kneader, stir under vacuum at 120-180°C for 1-3 h. After the temperature drops to 50-80°C, add cardanol substances and tackifier, and react under vacuum for 1-3 h; cool down to 20-40°C, then add hydrogen-containing silicone oil, and continue stirring for 10-30 min; then add inhibitor and catalyst, and continue stirring for 10-30 min to obtain component B; 3) Preparation of potting adhesive: Mix component A and component B evenly according to the mass ratio of (10-1):1, perform vacuum degassing, and cure at 80-120°C for 2-12 h to obtain a high-strength, low-density, high-temperature resistant silicone potting adhesive.

10. The application of the high-strength, low-density, high-temperature resistant silicone potting adhesive according to any one of claims 1 to 8 or the high-strength, low-density, high-temperature resistant silicone potting adhesive according to claim 9 in the fixing and potting of electronic components or power batteries.

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