A silicone adhesive sealant and a method for preparing the same

Abstract

The application relates to the technical field of bonding sealing materials, and provides an organic silicon bonding sealing material and a preparation method thereof, wherein the organic silicon bonding sealing material is prepared from the following components in parts by weight: alpha, omega-dihydroxypolydimethylsiloxane 100 parts, inorganic flame retardant 100-150 parts, dimethyl silicone oil 8-20 parts, nitrogen-phosphorus composite flame retardant 26-60 parts, platinum-containing flame retardant 0-2 parts, first organic silicon crosslinking agent 1.6-5 parts, second organic silicon crosslinking agent 1.6-5 parts, silane coupling agent 1.6-5 parts, and catalyst 1.6-5 parts; wherein the inorganic flame retardant is at least one selected from aluminum hydroxide and magnesium hydroxide. Through the above setting, the organic silicon bonding sealing material has good flame retardant performance and also maintains good bonding performance.

Description

Technical Field

[0001] This application relates to the field of adhesive sealing materials technology, and in particular to an organosilicon adhesive sealing material and its preparation method. Background Technology

[0002] With the rapid development of the electronics and new energy fields, silicone adhesives and sealants have become indispensable materials for ensuring the stable operation of various equipment due to their advantages such as good adhesion, weather resistance, chemical stability and electrical insulation properties.

[0003] However, with industry development, market demands for the safety of electronic devices are constantly increasing. Among these, flame retardant performance has become a key indicator that silicone adhesives and sealants urgently need to improve. Electronic devices are becoming increasingly integrated, with continuously increasing power density. This leads to increased heat generation from internal electronic components and a higher risk of electrical faults. If a short circuit generates an electrical spark, and the adhesive is not flame-retardant, it can easily ignite, causing the fire to spread rapidly. This can not only damage the equipment but also lead to data loss. In the new energy sector, taking new energy vehicle battery packs as an example, the high-temperature flames generated by battery thermal runaway, if not effectively blocked by flame-retardant adhesives and sealants, can cause vehicle fires or even explosions, seriously threatening personal and property safety. In solar power plants, if a fire is caused by non-flame-retardant adhesives and sealants, large-scale damage to photovoltaic modules can result in huge economic losses.

[0004] While existing conventional silicone adhesives and sealants possess good adhesion and sealing properties, their flame retardancy is insufficient. Traditional improvement methods involve adding flame retardants; however, the addition of large amounts of flame retardants can impair the original flexibility, bonding strength, and other properties of the silicone material, reducing sealing reliability. Therefore, there is an urgent need to develop a silicone adhesive and sealant material that possesses both highly efficient flame retardant properties and excellent adhesion. Summary of the Invention

[0005] The purpose of this application is to provide an organosilicon bonding and sealing material and its preparation method, so as to improve the flame retardant properties of the organosilicon bonding and sealing material while maintaining good bonding properties. The specific technical solution is as follows:

[0006] The first aspect of this application provides an organosilicon adhesive sealing material, which is prepared from the following components in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 100-150 parts of inorganic flame retardant, 8-20 parts of dimethyl silicone oil, 26-60 parts of nitrogen-phosphorus composite flame retardant, 0-2 parts of platinum-containing flame retardant, 1.6-5 parts of first organosilicon crosslinking agent, 1.6-5 parts of second organosilicon crosslinking agent, 1.6-5 parts of silane coupling agent, and 1.6-5 parts of catalyst; wherein the inorganic flame retardant is selected from at least one of aluminum hydroxide and magnesium hydroxide.

[0007] In some embodiments of this application, the viscosity of the α,ω-dihydroxypolydimethylsiloxane is 500~50000 mPa·s; preferably, the viscosity of the α,ω-dihydroxypolydimethylsiloxane is 20000~50000 mPa·s.

[0008] In some embodiments of this application, the viscosity of the dimethyl silicone oil is 50~500 mPa·s; preferably, the viscosity of the dimethyl silicone oil is 50~100 mPa·s.

[0009] In some embodiments of this application, the particle size D50 of the inorganic flame retardant is 2~20μm; preferably, the particle size D50 of the inorganic flame retardant is 2~10μm.

[0010] In some embodiments of this application, the nitrogen-phosphorus composite flame retardant is selected from at least one of ammonium polyphosphate, melamine polyphosphate, and hexaphenoxycyclotriphosphazene.

[0011] In some embodiments of this application, the first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from one of methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; the first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from different substances.

[0012] In some embodiments of this application, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane.

[0013] In some embodiments of this application, the catalyst is selected from at least one of tetraisopropyl titanate, tert-butyl titanate, titanate complex, dibutyltin diacetate, dibutyltin dilaurate, and organotin chelates.

[0014] A second aspect of this application provides a method for preparing the silicone adhesive sealing material provided in the first aspect of this application, which includes the following steps:

[0015] (1) Mix α,ω-dihydroxypolydimethylsiloxane and inorganic flame retardant and remove water, then grind to obtain masterbatch;

[0016] (2) After cooling the masterbatch obtained in step (1), the masterbatch is mixed with dimethyl silicone oil, nitrogen-phosphorus composite flame retardant, first organosilicon crosslinking agent, second organosilicon crosslinking agent, silane coupling agent and platinum-containing flame retardant, and stirred for the first time under vacuum conditions; then a catalyst is added and stirred for the second time under vacuum conditions to obtain organosilicon bonding and sealing material.

[0017] In some embodiments of this application, the temperature of the mixing and dehydration in step (1) is 120~150℃, the stirring speed is 2000~3000rpm, the vacuum degree is -0.1MPa to -0.095MPa, and the time is 2~3h.

[0018] In some embodiments of this application, in step (2), the cooling temperature is ≤40℃; the vacuum degree of the first stirring is -0.1MPa to -0.095MPa, the stirring speed is 20~50rpm, and the stirring time is 20~30min; the vacuum degree of the second stirring is -0.1MPa to -0.095MPa, the stirring speed is 20~50rpm, and the stirring time is 30~50min.

[0019] The beneficial effects of this application are:

[0020] This application provides an organosilicon bonding and sealing material and its preparation method. The organosilicon bonding and sealing material is prepared from the following components in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 100-150 parts of inorganic flame retardant, 8-20 parts of dimethyl silicone oil, 26-60 parts of nitrogen-phosphorus composite flame retardant, 0-2 parts of platinum-containing flame retardant, 1.6-5 parts of first organosilicon crosslinking agent, 1.6-5 parts of second organosilicon crosslinking agent, 1.6-5 parts of silane coupling agent, and 1.6-5 parts of catalyst; wherein the inorganic flame retardant is selected from at least one of aluminum hydroxide and magnesium hydroxide. Through the above configuration, the organosilicon bonding and sealing material of this application possesses both good flame retardant properties and good bonding properties.

[0021] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Detailed Implementation

[0022] The technical solutions in this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0023] The first aspect of this application provides an organosilicon adhesive sealing material, which is prepared from the following components in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 100-150 parts of inorganic flame retardant, 8-20 parts of dimethyl silicone oil, 26-60 parts of nitrogen-phosphorus composite flame retardant, 0-2 parts of platinum-containing flame retardant, 1.6-5 parts of first organosilicon crosslinking agent, 1.6-5 parts of second organosilicon crosslinking agent, 1.6-5 parts of silane coupling agent, and 1.6-5 parts of catalyst; wherein the inorganic flame retardant is selected from at least one of aluminum hydroxide and magnesium hydroxide.

[0024] Research has found that the silicone adhesive sealing material prepared according to the raw materials and proportions of this application possesses both good flame retardant properties and good adhesive properties. This application uses an inorganic flame retardant as the main flame retardant. Inorganic flame retardants are characterized by low smoke emission, low toxicity, and low generation of harmful gases, and have a high decomposition temperature and large heat absorption, effectively reducing the material temperature and the concentration of combustible gases, thereby achieving a flame retardant effect. Simultaneously, within the scope of this application, inorganic flame retardants help reduce curing shrinkage and interfacial stress, thereby improving the adhesive performance of the silicone adhesive sealing material. Furthermore, the silicone adhesive sealing material of this application also includes a nitrogen-phosphorus composite flame retardant. On the one hand, during combustion, the nitrogen-phosphorus composite flame retardant promotes the formation of a dense carbon layer on the material surface, isolating oxygen and heat transfer and preventing further spread of combustion. On the other hand, during combustion, the nitrogen-phosphorus composite flame retardant releases non-combustible gases, such as carbon dioxide and nitrogen, thereby diluting the concentration of combustible gases and oxygen, capturing free radicals, interrupting the combustion chain reaction, and achieving a further flame retardant effect. Furthermore, the addition of nitrogen-phosphorus composite flame retardants helps reduce the total amount of inorganic flame retardants required to achieve the required flame retardant rating, thereby improving the mechanical and processing properties of the silicone adhesive sealing material. The combined use of inorganic flame retardants and nitrogen-phosphorus composite flame retardants also helps reduce the amount of nitrogen-phosphorus composite flame retardants used, lowering production costs. The silicone adhesive sealing material of this application simultaneously comprises α,ω-dihydroxypolydimethylsiloxane, inorganic flame retardant, dimethyl silicone oil, nitrogen-phosphorus composite flame retardant, a first silicone crosslinking agent, a second silicone crosslinking agent, a silane coupling agent, and a catalyst. The weight proportions of each component are controlled within the scope of this application, and the components work synergistically to ensure that the silicone adhesive sealing material possesses both excellent flame retardant properties and good adhesive properties. Furthermore, the silicone adhesive sealing material of this application may also include a platinum-containing flame retardant. The platinum-containing flame retardant, through catalysis, causes the side chain organic groups of the silicone adhesive sealing material to undergo an oxidative cross-linking reaction, thereby increasing the cross-linking density, thus improving the thermal stability of the silicone adhesive sealing material, preventing its further decomposition, and also helping to increase the content of residues after combustion, promoting the formation of a ceramic layer, and thus isolating the air and extinguishing the flame.

[0025] This application uses α,ω-dihydroxypolydimethylsiloxane as the base adhesive, and combines it with inorganic flame retardants, inorganic flame retardants, nitrogen-phosphorus composite flame retardants, platinum-containing flame retardants, a first organosilicon crosslinking agent, a second organosilicon crosslinking agent, silane coupling agents, and catalysts. The content of each substance is controlled within the scope of this application. The components work synergistically to make the organosilicon adhesive sealant have both good flame retardant properties and good adhesion properties.

[0026] In some embodiments of this application, the adhesive sealing material is prepared from the following components in parts by weight:

[0027] The composition comprises 100 parts α,ω-dihydroxypolydimethylsiloxane, 120-150 parts inorganic flame retardant, 8-20 parts dimethyl silicone oil, 26-40 parts nitrogen-phosphorus composite flame retardant, 0-2 parts platinum-containing flame retardant, 1.6-5 parts first organosilicon crosslinking agent, 1.6-5 parts second organosilicon crosslinking agent, 1.6-5 parts silane coupling agent, and 1.6-5 parts catalyst. By adjusting the content of each substance within the scope of this application, the components work synergistically to enable the organosilicon adhesive sealing material to possess both good flame retardant properties and good adhesive properties.

[0028] In some embodiments of this application, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 500~50000 mPa·s; preferably, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 20000~50000 mPa·s. For example, the viscosity of α,ω-dihydroxypolydimethylsiloxane can be 500 mPa·s, 1000 mPa·s, 15000 mPa·s, 20000 mPa·s, 25000 mPa·s, 30000 mPa·s, 35000 mPa·s, 40000 mPa·s, 45000 mPa·s, 50000 mPa·s, or a range consisting of any two of these values. By adjusting the viscosity of α,ω-dihydroxypolydimethylsiloxane within the range specified in this application, it is beneficial to control the viscosity of the silicone adhesive sealant within a suitable range, which is beneficial to enhance the adhesive performance of the silicone adhesive sealant and to adjust the curing speed and curing performance.

[0029] In some embodiments of this application, the viscosity of the dimethyl silicone oil is 50~500 mPa·s; preferably, the viscosity of the dimethyl silicone oil is 50~100 mPa·s. For example, the viscosity of the dimethyl silicone oil can be 50 mPa·s, 80 mPa·s, 100 mPa·s, 150 mPa·s, 200 mPa·s, 250 mPa·s, 300 mPa·s, 350 mPa·s, 400 mPa·s, 450 mPa·s, 500 mPa·s, or a range of any two of these values. By adjusting the viscosity of the dimethyl silicone oil to within the range specified in this application, it is beneficial to control the viscosity of the silicone adhesive sealant within a suitable range, which is beneficial to enhance the adhesive performance of the silicone adhesive sealant and to adjust the curing speed and curing performance.

[0030] In some embodiments of this application, the particle size D50 of the inorganic flame retardant is 2~20μm, preferably 2~10μm. For example, the particle size D50 of the inorganic flame retardant can be 2μm, 5μm, 8μm, 10μm, 12μm, 15μm, 18μm, 20μm, or a range of any two values ​​therein. By controlling the average particle size of the inorganic flame retardant within the range of this application, and in combination with other components of this application, it is beneficial to improve the flame retardant properties of the silicone adhesive sealant while maintaining good adhesion properties. When the particle size D50 of the inorganic flame retardant is too small, for example, less than 2μm, it will increase the viscosity of the silicone adhesive sealant, affecting subsequent processing performance; when the particle size D50 of the inorganic flame retardant is too large, for example, greater than 20μm, it will result in a lower viscosity of the silicone adhesive sealant, reduced mechanical strength, and reduced tensile and shear strength. Wherein, D50 is the particle size corresponding to 50% of the total volume in the particle size distribution of inorganic flame retardant particles, measured from the smallest particle size. In this application, the inorganic flame retardant can be prepared or purchased, and the required particle size of the inorganic flame retardant is selected in conjunction with the "Test of D50 of Inorganic Flame Retardant" provided in this application.

[0031] In some embodiments of this application, the nitrogen-phosphorus composite flame retardant is selected from at least one of ammonium polyphosphate (APP), melamine polyphosphate (MPP), and hexaphenoxycyclotriphosphazene. By selecting a nitrogen-phosphorus composite flame retardant within the scope of this application, it is beneficial to maximize its flame-retardant effect. On the one hand, during combustion, the nitrogen-phosphorus composite flame retardant can promote the formation of a dense carbon layer on the material surface, isolating oxygen and heat transfer and preventing the spread of combustion. On the other hand, the nitrogen-phosphorus composite flame retardant releases non-combustible gases during combustion, thereby diluting the concentration of combustible gases and oxygen, capturing free radicals, interrupting the combustion chain reaction, and achieving a further flame-retardant effect. If the weight percentage of nitrogen-phosphorus composite flame retardant in the raw material components of organosilicon adhesive sealant is too low, for example, less than 26 parts, it is not conducive to improving the flame retardant performance of the prepared inorganic silicone adhesive sealant, and the flame retardant rating cannot reach V-0. If the weight percentage of nitrogen-phosphorus composite flame retardant in the raw material components of organosilicon adhesive sealant is too high, for example, more than 60 parts, it is not conducive to improving the mechanical strength of organosilicon adhesive sealant, not conducive to improving the bonding performance of organosilicon adhesive sealant, and will lead to an increase in the cost of organosilicon adhesive sealant.

[0032] In some embodiments of this application, the first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from one of methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; the first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from different substances. This application uses two different organosilicon crosslinking agents, which work synergistically to achieve crosslinking and curing, and can simultaneously take into account the surface drying time and mechanical properties of the organosilicon adhesive sealant.

[0033] In some embodiments of this application, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane (KH-550), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560), γ-mercaptopropyltrimethoxysilane (KH-590), and γ-(methacryloyloxy)propyltrimethoxysilane (KH-570). By selecting a silane coupling agent within the scope of this application, and using it in combination with the first and second organosilicon crosslinking agents of this application, it is beneficial for the organosilicon adhesive sealant to achieve adhesion to different substrates during curing, thereby improving the adhesion performance of the organosilicon adhesive sealant.

[0034] In some embodiments of this application, the catalyst is selected from at least one of tetraisopropyl titanate, tert-butyl titanate, titanate complex, dibutyltin diacetate, dibutyltin dilaurate, and organotin chelates. The titanate complex may be selected from at least one of titanium acetylacetonate, titanium ethyl acetoacetate, and titanium lactate; the organotin chelate may be selected from at least one of dibutyltin acetylacetonate and dibutyltin dimercaptoacetate. Using catalysts within the scope of this application is beneficial for accelerating the curing speed of silicone adhesive sealants.

[0035] In this application, the platinum-containing flame retardant is selected from at least one of platinum-divinyltetramethyldisiloxane complex (CAS No.: 68478-92-2), platinum-cyclovinylmethylsiloxane complex (CAS No.: 68951-97-9), and isopropanol chloroplatinate solution (CAS No.: 51849-78-2). By using the platinum-containing catalyst of this application, the side chain organic groups of the organosilicon adhesive sealant undergo an oxidative crosslinking reaction, increasing the crosslinking density, thereby improving the thermal stability of the organosilicon adhesive sealant, preventing its further decomposition, and also increasing the content of residues after combustion, promoting the formation of a ceramic layer, and thus isolating the air and extinguishing the flame.

[0036] This application does not impose any particular limitation on the source of α,ω-dihydroxypolydimethylsiloxane, inorganic flame retardant, dimethyl silicone oil, nitrogen-phosphorus composite flame retardant, platinum-containing flame retardant, first organosilicon crosslinking agent, second organosilicon crosslinking agent, silane coupling agent and catalyst, which can be obtained by purchase or by preparation.

[0037] A second aspect of this application provides a method for preparing the silicone adhesive sealing material provided in the first aspect of this application, which includes the following steps:

[0038] (1) Mix α,ω-dihydroxypolydimethylsiloxane and inorganic flame retardant and remove water, then grind to obtain masterbatch;

[0039] (2) After cooling the masterbatch obtained in step (1), the masterbatch is mixed with dimethyl silicone oil, nitrogen-phosphorus composite flame retardant, first organosilicon crosslinking agent, second organosilicon crosslinking agent, silane coupling agent and platinum-containing flame retardant, and stirred for the first time under vacuum conditions; then a catalyst is added and stirred for the second time under vacuum conditions to obtain organosilicon bonding and sealing material.

[0040] This application does not impose any particular restrictions on the apparatus used for mixing and dehydration in step (1), as long as it can achieve the purpose of this application. For example, a planetary mixer can be used. This application does not impose any particular restrictions on the apparatus used for grinding in step (1), as long as it can achieve the purpose of this application. For example, a three-roll mill can be used. This application does not impose any particular restrictions on the apparatus used for the first and second stirring in step (2), as long as it can achieve the purpose of this application. For example, a planetary mixer can be used.

[0041] In some embodiments of this application, the mixing and dehydration temperature in step (1) is 120~150℃, the stirring speed is 2000~3000rpm, the vacuum degree is -0.1MPa to -0.095MPa, and the time is 2~3h. For example, the mixing and dehydration temperature can be 120℃, 130℃, 140℃, 150℃, or any two of these values; the stirring speed can be 2000rpm, 2200rpm, 2500rpm, 2800rpm, 3000rpm, or any two of these values; the vacuum degree can be -0.1MPa, -0.099MPa, -0.098MPa, -0.097MPa, -0.096MPa, -0.095MPa, or any two of these values; and the time can be 2h, 2.2h, 2.5h, 2.8h, 3h, or any two of these values. Through the above steps, a well-dispersed and dehydrated masterbatch can be obtained. By adjusting the temperature, stirring speed, vacuum degree and stirring time in step (1) within the above range, it is beneficial to remove moisture from α,ω-dihydroxypolydimethylsiloxane and inorganic flame retardant, and to mix α,ω-dihydroxypolydimethylsiloxane and inorganic flame retardant evenly to obtain masterbatch.

[0042] In some embodiments of this application, in step (2), the cooling temperature is ≤40℃, for example, the cooling temperature can be 40℃, 38℃, 35℃, 32℃, 30℃, 28℃, 25℃, or a range of any two of these values; the vacuum degree of the first stirring is -0.1MPa to -0.095 MPa. The vacuum level for the first stirring is -0.1 MPa, -0.099 MPa, -0.098 MPa, -0.097 MPa, -0.096 MPa, -0.095 MPa, or any two of these values. The stirring speed is 20 rpm, 25 rpm, 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, or any two of these values. The stirring time is 20 min, 22 min, 25 min, 28 min, 30 min, or any two of these values. The vacuum level for the second stirring is -0.1 MPa to -0.095 MPa, and the stirring speed is 20-50 rpm. The stirring speed is 30-50 min, and the stirring time is 30-50 min. For example, the vacuum degree of the second stirring can be -0.1 MPa, -0.099 MPa, -0.098 MPa, -0.097 MPa, -0.096 MPa, -0.095 MPa, or any two of these values. The stirring speed can be 20 rpm, 25 rpm, 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, or any two of these values. The stirring time can be 30 min, 35 min, 40 min, 45 min, 50 min, or any two of these values. By controlling the temperature, stirring speed, stirring speed, and vacuum degree in step (2) within the above ranges, it is beneficial to reduce the occurrence of side reactions and reduce the local crosslinking reaction between the polymer and the crosslinking agent.

[0043] The preparation method provided in this application is simple and suitable for large-scale production. The resulting organosilicon adhesive sealing material has good dispersibility and stability.

[0044] Example

[0045] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Unless otherwise specified, "parts" and "%" refer to mass. All raw materials used in the embodiments and comparative examples of this application are commercially available.

[0046] Test methods and equipment:

[0047] Performance testing of silicone adhesive sealant

[0048] According to industry standard HG / T 5379-2018 "Organic Silicone Sealants for Electrical Appliances", the surface drying time, Shore hardness, tensile strength, elongation at break, shear strength and flame retardancy rating of the organosilicon bonding and sealing materials prepared in the various embodiments and comparative examples of this application were tested.

[0049] Specific gravity refers to the density of a substance (in its completely dense state) compared to the density of pure H₂O at standard atmospheric pressure and 3.98°C (999.972 kg / m³). 3 The ratio of ) to the specific gravity of the silicone adhesive sealant was tested using a hydrometer in this application.

[0050] Shear strength reflects the bonding performance of silicone adhesive sealants; the higher the shear strength, the better the bonding performance of the silicone adhesive sealant.

[0051] Viscosity test

[0052] The viscosity of the samples was tested using a Brookfield dial rotational viscometer. This method can be used to test the viscosity of α,ω-dihydroxypolydimethylsiloxane, dimethyl silicone oil, and silicone adhesive sealant materials used in this application.

[0053] Testing of particle size D50 of inorganic flame retardants

[0054] The particle size distribution of the inorganic flame retardant was tested using a laser particle size analyzer (Malvin MS300) to obtain the particle size D50. The specific testing was conducted according to the national standard GB / T19077-2024, "Particle Size Distribution - Laser Diffraction Method". D50 represents the particle size corresponding to 50% of the cumulative volume in the volumetric particle size distribution curve of the material, starting from the smallest particle size.

[0055] Example 1

[0056] Table 1

[0057] Table 1 shows the specific substances and weight parts of each component in Example 1. Among them, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 20000 mPa·s, the viscosity of dimethyl silicone oil is 100 mPa·s, and the particle size D50 of aluminum hydroxide is 10 μm.

[0058] Preparation of silicone adhesive sealing materials:

[0059] (1) Add α,ω-dihydroxypolydimethylsiloxane and aluminum hydroxide to a planetary mixer, turn on the high-speed disperser, adjust the speed to 2500 rpm, the temperature to 135℃, and vacuum dehydrate for 2.5 h under a vacuum of -0.1 MPa. Then pass the mixture through a three-roll mill to obtain the masterbatch.

[0060] (2) When the temperature of the masterbatch drops to 30°C, add dimethyl silicone oil, ammonium polyphosphate, methyltrimethoxysilane, vinyltrimethoxysilane, and γ-aminopropyltriethoxysilane KH-550. Under a vacuum of -0.1 MPa, adjust the speed to 35 rpm and stir for 25 min. Then add tetraisopropyl titanate and under a vacuum of -0.1 MPa, maintain the speed at 35 rpm and stir for 35 min before discharging to obtain the organosilicon adhesive sealant.

[0061] Example 2

[0062] Table 2

[0063] Table 2 shows the specific substances and weight parts of each component in Example 2. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 2, the rest is the same as in Example 1.

[0064] Example 3

[0065] Table 3

[0066] Table 3 shows the specific substances and weight parts of each component in Example 3. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 3, the rest is the same as in Example 1.

[0067] Example 4

[0068] Table 4

[0069] Table 4 shows the specific substances and weight parts of each component in Example 4. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 4, the rest is the same as in Example 1.

[0070] Example 5

[0071] Table 5

[0072] Table 5 shows the specific substances and weight parts of each component in Example 5. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 5, the rest is the same as in Example 1.

[0073] Example 6

[0074] Table 6

[0075] Table 6 shows the specific substances and weight parts of each component in Example 6. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 6, the rest is the same as in Example 1.

[0076] Example 7

[0077] Table 7

[0078] Table 7 shows the specific substances and weight parts of each component in Example 7. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 7, the rest is the same as in Example 1.

[0079] Example 8

[0080] Table 8

[0081] Table 8 shows the specific substances and weight parts of each component in Example 8. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 8, the rest is the same as in Example 1. The platinum-containing flame retardant is a platinum-divinyltetramethyldisiloxane complex, CAS number 68478-92-2.

[0082] Example 9

[0083] Except for adjusting the particle size D50 of aluminum hydroxide to 2 μm, the rest is the same as in Example 1.

[0084] Example 10

[0085] Except for adjusting the particle size D50 of aluminum hydroxide to 20 μm, the rest is the same as in Example 1.

[0086] Example 11

[0087] Except for adjusting the viscosity of α,ω-dihydroxypolydimethylsiloxane to 50,000 mPa·s, the rest is the same as in Example 1.

[0088] Example 12

[0089] Except for adjusting the viscosity of α,ω-dihydroxypolydimethylsiloxane to 500 mPa·s, the rest is the same as in Example 1.

[0090] Example 13

[0091] Except for adjusting the viscosity of the dimethyl silicone oil to 50 mPa·s, the rest is the same as in Example 1.

[0092] Example 14

[0093] Except for adjusting the viscosity of the dimethyl silicone oil to 500 mPa·s, the rest is the same as in Example 1.

[0094] Comparative Example 1

[0095] Table 9

[0096] Table 9 shows the specific substances and weight parts of each component in Comparative Example 1. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 9, the rest is the same as in Example 1.

[0097] Comparative Example 2

[0098] Table 10

[0099] Table 10 shows the specific substances and weight parts of each component in Comparative Example 2. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 10, the rest is the same as in Example 1.

[0100] Comparative Example 3

[0101] Table 11

[0102] Table 11 shows the specific substances and weight parts of each component in Comparative Example 3. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 11, the rest is the same as in Example 1.

[0103] Comparative Example 4

[0104] Table 12

[0105] Table 12 shows the specific substances and weight parts of each component in Comparative Example 4. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 12, and excluding the nitrogen-phosphorus composite flame retardant, the rest is the same as in Example 1.

[0106] Comparative Example 5

[0107] Table 13

[0108] Table 13 shows the specific substances and weight parts of each component in Comparative Example 5. Except for adjusting the types and weight parts of each component of the silicone adhesive sealant according to Table 13, the rest is the same as in Example 1.

[0109] Table 14 shows the test results for each embodiment and comparative example.

[0110] Table 14

[0111] As can be seen from Examples 1 to 14 in Table 14, by adjusting the weight ratio of each component within the scope of this application, the flame retardancy rating of the obtained silicone adhesive sealant can reach V-0, the shear strength is high, and other properties meet the requirements. This indicates that the silicone adhesive sealant of this application can take into account both flame retardancy and adhesive properties. Comparative Example 1 did not use any inorganic flame retardant within the scope of this application, and its flame retardant rating was V-2, indicating that the silicone adhesive sealant of Comparative Example 1 had poor flame retardant performance. Comparative Example 2 had less than 100 parts by weight of inorganic flame retardant, and its flame retardant rating was V-1, indicating that the silicone adhesive sealant of Comparative Example 2 had poor flame retardant performance. Comparative Example 3 had more than 150 parts by weight of inorganic flame retardant and less than 26 parts by weight of nitrogen-phosphorus composite flame retardant. Although the shear strength increased, the flame retardant rating was still V-1, indicating that the silicone adhesive sealant of Comparative Example 3 could not simultaneously achieve both bonding performance and flame retardant performance. Comparative Example 4 did not include nitrogen-phosphorus composite flame retardant, and its flame retardant rating was V-1, indicating that the silicone adhesive sealant of Comparative Example 4 had poor flame retardant performance. Comparative Example 5 had more than 60 parts by weight of nitrogen-phosphorus composite flame retardant, and its shear strength decreased to only 1.4 MPa, indicating that the silicone adhesive sealant of Comparative Example 5 had poor bonding performance.

[0112] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An organosilicon adhesive sealant, comprising the following components in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 100-150 parts of inorganic flame retardant, 8-20 parts of dimethyl silicone oil, 26-60 parts of nitrogen-phosphorus composite flame retardant, 0-2 parts of platinum-containing flame retardant, 1.6-5 parts of first organosilicon crosslinking agent, 1.6-5 parts of second organosilicon crosslinking agent, 1.6-5 parts of silane coupling agent, and 1.6-5 parts of catalyst; in, The inorganic flame retardant is selected from at least one of aluminum hydroxide and magnesium hydroxide; The nitrogen-phosphorus composite flame retardant is selected from at least one of ammonium polyphosphate, melamine polyphosphate and hexaphenoxycyclotriphosphazene; The first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from one of methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; the first organosilicon crosslinking agent and the second organosilicon crosslinking agent are selected from different substances; The viscosity of the α,ω-dihydroxypolydimethylsiloxane is 500~45000 mPa·s; The particle size D50 of the inorganic flame retardant is 2~15μm.

2. The silicone adhesive sealing material according to claim 1, wherein, The viscosity of the α,ω-dihydroxypolydimethylsiloxane is 20,000~45,000 mPa·s.

3. The silicone adhesive sealing material according to claim 1, wherein, The viscosity of the dimethyl silicone oil is 50~500 mPa·s.

4. The silicone adhesive sealing material according to claim 1, wherein, The viscosity of the dimethyl silicone oil is 50~100 mPa·s.

5. The silicone adhesive sealing material according to claim 1, wherein, The particle size D50 of the inorganic flame retardant is 2~10μm.

6. The silicone adhesive sealing material according to claim 1, wherein, The silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane; and / or, the catalyst is selected from at least one of tetraisopropyl titanate, tert-butyl titanate, titanate complex, dibutyltin diacetate, dibutyltin dilaurate, and organotin chelates.

7. A method for preparing an organosilicon adhesive sealant according to any one of claims 1 to 6, comprising the following steps: (1) Mix α,ω-dihydroxypolydimethylsiloxane and inorganic flame retardant and remove water, then grind to obtain masterbatch; (2) After cooling the masterbatch obtained in step (1), the masterbatch is mixed with dimethyl silicone oil, nitrogen-phosphorus composite flame retardant, first organosilicon crosslinking agent, second organosilicon crosslinking agent, silane coupling agent and platinum-containing flame retardant, and stirred for the first time under vacuum conditions; then a catalyst is added and stirred for the second time under vacuum conditions to obtain organosilicon bonding and sealing material.

8. The method for preparing the organosilicon adhesive sealing material according to claim 7, wherein, In step (1), the temperature for mixing and dehydration is 120~150℃, the stirring speed is 2000~3000rpm, the vacuum degree is -0.1MPa to -0.095MPa, and the time is 2~3h.

9. The method for preparing the organosilicon adhesive sealing material according to claim 7, wherein, In step (2), the cooling temperature is ≤40℃; the vacuum degree of the first stirring is -0.1MPa to -0.095MPa, the stirring speed is 20~50rpm, and the stirring time is 20~30min; the vacuum degree of the second stirring is -0.1MPa to -0.095MPa, the stirring speed is 20~50rpm, and the stirring time is 30~50min.

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