Modified silicone rubber and its preparation method, flame retardant products

Abstract

This application relates to modified silicone rubber, its preparation method, and flame-retardant products. The modified silicone rubber comprises silicone rubber and modified nano-calcium fluoride distributed within the silicone rubber, wherein the modified nano-calcium fluoride includes nano-calcium fluoride modified with a silane coupling agent. The raw materials for preparing the silicone rubber include a first raw material and a second raw material. By mass parts, the first raw material comprises: 40-80 parts of vinyl silicone resin, 30-60 parts of vinyl silicone oil, 10-20 parts of MQ silicone resin without active hydrogen, 1-5 parts of vinyl cage-type polysilsesquioxane, a catalyst, and a first diluent. By mass parts, the second raw material comprises: 10-50 parts of hydrogen-containing silicone oil, 10-20 parts of MQ silicone resin, 0-5 parts of vinyl cage-type polysilsesquioxane without vinyl, an inhibitor, and a second diluent. The modified silicone rubber exhibits both excellent flame-retardant and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of silicone technology, and in particular to modified silicone and its preparation methods, and flame-retardant products. Background Technology

[0002] Organosilicon, with polysiloxane as its main material, is widely used in electronics, aerospace, automobile manufacturing and construction due to its excellent high and low temperature resistance, superior electrical insulation, good chemical stability and elasticity.

[0003] However, most silicone polymers are flammable materials that continue to burn and release heat when heated in air, potentially producing toxic fumes. This poses a significant fire hazard and severely limits their application prospects in high-end and critical safety fields. Traditional flame-retardant strategies typically involve adding halogenated flame retardants. While these have high flame-retardant efficiency, they produce large amounts of corrosive and toxic fumes during combustion, posing significant harm to the environment and human health, and are gradually being phased out by industry regulations.

[0004] Therefore, traditional technologies still need improvement. Summary of the Invention

[0005] Therefore, it is necessary to provide a modified silicone rubber with both excellent flame retardant and mechanical properties, its preparation method, and flame retardant products.

[0006] This application is achieved through the following technical solution:

[0007] One aspect of this application provides a modified organosilicon, comprising organosilicon and modified nano-calcium fluoride distributed in the organosilicon, wherein the modified nano-calcium fluoride comprises silane coupling agent modified nano-calcium fluoride.

[0008] The raw materials for preparing the silicone include a first raw material and a second raw material;

[0009] The components of the first raw material, by mass parts, include: 40 to 80 parts of vinyl silicone resin, 30 to 60 parts of vinyl silicone oil, 10 to 20 parts of MQ silicone resin without active hydrogen, 1 to 5 parts of vinyl cage-type polysilsesquioxane, catalyst, and first diluent.

[0010] The second raw material comprises, by weight parts: 10 to 50 parts of hydrogen-containing silicone oil, 10 to 20 parts of MQ silicone resin, 0 to 5 parts of vinyl-free cage-type polysilsesquioxane, inhibitor, and second diluent.

[0011] In some embodiments, the modified nano-calcium fluoride accounts for 1% to 10% of the total mass of the first raw material in the raw materials for preparing the silicone.

[0012] And / or, the particle size of the modified nano-calcium fluoride is 20nm~90nm.

[0013] In some embodiments, the mass ratio of the first raw material to the second raw material in the preparation of the silicone is 1:(0.5~1.5).

[0014] In some embodiments, the vinyl content in the vinyl-containing silicone resin is 0.9% to 1.9% by mass.

[0015] And / or, the viscosity of the vinyl silicone oil at 25°C is 300 cps to 10000 cps;

[0016] And / or, in the hydrogen-containing silicone oil, the mass fraction of hydrogen is 0.1% to 0.5%;

[0017] And / or, the catalyst comprises a platinum-type catalyst;

[0018] And / or, the inhibitor includes one or more of alkynyl alcohol inhibitors or silicone inhibitors.

[0019] Another aspect of this application provides a method for preparing the above-mentioned modified organosilicone, comprising the following steps:

[0020] The first raw material, the second raw material, and the modified nano-calcium fluoride are mixed and cured to prepare the modified organosilicon.

[0021] In some embodiments, the preparation method of the modified nano-calcium fluoride includes the following steps:

[0022] A calcium salt solution and a fluoride salt solution were mixed to carry out a co-precipitation reaction, and the precipitate was collected to prepare calcium fluoride.

[0023] Modified nano-calcium fluoride is prepared by mixing the calcium fluoride, silane coupling agent, and solvent.

[0024] In some embodiments, the concentration of calcium ions in the calcium salt solution is 0.05 mol / L to 0.15 mol / L;

[0025] And / or, the fluoride ion concentration in the fluoride salt solution is 0.1 mol / L to 0.3 mol / L;

[0026] And / or, the calcium salt in the calcium salt solution includes one or more of calcium chloride, calcium nitrate, calcium hydroxide, calcium oxide, and calcium carbonate;

[0027] And / or, the fluoride salt in the fluoride solution includes one or more of ammonium fluoride, sodium fluoride, potassium fluoride, and sodium fluorosilicate.

[0028] In some embodiments, the precipitation reaction is carried out at a temperature of 20°C to 30°C for a time of 30 min to 120 min.

[0029] And / or, the temperature for mixing the calcium fluoride, silane coupling agent and solvent is 40°C to 60°C, and the time is 60 min to 240 min;

[0030] And / or, the curing temperature is 70℃~80℃, and the time is 15min~240min.

[0031] In some embodiments, the silane coupling agent includes one or more of KH560, KH570, and KH550;

[0032] And / or, the solvent includes one or more of ethanol, water, methanol and isopropanol.

[0033] Another aspect of this application provides a flame-retardant article comprising the modified silicone rubber described above or the modified silicone rubber prepared by the above-described method.

[0034] The modified silicone rubber of this application involves introducing a silane coupling agent into nano-calcium fluoride for modification, and simultaneously filling the modified nano-calcium fluoride into a specific silicone rubber. Combined with the high thermal stability, chemical inertness, non-toxicity, and low cost of the modified nano-calcium fluoride, it effectively inhibits heat transfer, hinders the diffusion of combustible gases, and isolates oxygen, significantly improving the flame retardant performance of the modified silicone rubber. By controlling the specific ratio of each raw material, the components work synergistically, allowing the addition of modified nano-calcium fluoride to improve the flame retardancy of the material while maintaining the excellent mechanical properties of the silicone rubber. This results in a modified silicone rubber with both excellent flame retardant and mechanical properties, thereby broadening its application areas. Attached Figure Description

[0035] Figure 1 The images show the SEM morphology and particle size analysis of the calcium fluoride nanomaterials obtained in Example 1. Figure 1 In the image, 'a' represents the SEM topography. Figure 1 In the middle b, the particle size analysis diagram is shown. The horizontal axis represents the diameter of the particles, and the vertical axis represents the number of particles within the corresponding diameter range.

[0036] Figure 2 To illustrate the results of the heat release rate, total heat release, CO release rate, and total smoke emission of the modified silicone rubber obtained in Examples 1-4 and Comparative Example 1 in the cone test, the following curves are provided: Figure 2 In the figure, 'a' represents the heat release rate curve, with time on the horizontal axis and heat release rate on the vertical axis. Figure 2 In the figure, b represents the total heat release curve, with the horizontal axis representing time and the vertical axis representing the total heat release. Figure 2 In the curve, 'c' represents the CO release rate, with time on the x-axis and CO formation rate on the y-axis. Figure 2 In the figure, d represents the total smoke release curve, with the horizontal axis representing time and the vertical axis representing the total smoke release. Detailed Implementation

[0037] To facilitate understanding of this application, a more complete description is provided below, along with preferred embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0038] The implementation of this application will be described in detail below with reference to some implementation methods and embodiments. This embodiment is implemented based on the technical solution of this application, and provides detailed implementation methods and specific operation processes, but the protection scope of this application is not limited to the following embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0040] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0041] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0042] In this application, terms such as "further" and "especially" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0043] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0044] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, including the two endpoint integers of the numerical range, as well as every integer between the two endpoints, is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0045] In this application, the term "room temperature" generally refers to 4℃ to 35℃, and preferably 20℃ ± 5℃. In some embodiments of this application, room temperature refers to 20℃ to 30℃.

[0046] In this application, unless otherwise specified, the temperature parameters are permitted to be either constant temperature treatment or variations within a certain temperature range. It should be understood that the constant temperature treatment allows temperature fluctuations within the precision range controlled by the instrument. Fluctuations are permitted within ranges such as ±5℃, ±4℃, ±3℃, ±2℃, and ±1℃.

[0047] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 2~5h means that the units of the left endpoint "2" and the right endpoint "5" are both h (hours).

[0048] One embodiment of this application provides a modified organosilicone material, comprising organosilicone and modified nano-calcium fluoride distributed in the organosilicone material, wherein the modified nano-calcium fluoride comprises nano-calcium fluoride modified with a silane coupling agent.

[0049] The raw materials for preparing the above-mentioned silicone include a first raw material and a second raw material;

[0050] The components of the first raw material, by mass parts, include: 40 to 80 parts of vinyl silicone resin, 30 to 60 parts of vinyl silicone oil, 10 to 20 parts of MQ silicone resin without active hydrogen, 1 to 5 parts of vinyl cage-type polysilsesquioxane, catalyst, and first diluent.

[0051] By mass, the components of the second raw material include: 10 to 50 parts of hydrogen-containing silicone oil, 10 to 20 parts of MQ silicone resin, 0 to 5 parts of vinyl-free cage-type polysilsesquioxane, inhibitor, and second diluent.

[0052] The modified silicone rubber of this application involves introducing a silane coupling agent into nano-calcium fluoride for modification, and simultaneously filling the modified nano-calcium fluoride into a specific silicone rubber. Combined with the high thermal stability, chemical inertness, non-toxicity, and low cost of the modified nano-calcium fluoride, it effectively inhibits heat transfer, hinders the diffusion of combustible gases, and isolates oxygen, significantly improving the flame retardant performance of the modified silicone rubber. By controlling the specific ratio of each raw material, the components work synergistically, allowing the addition of modified nano-calcium fluoride to improve the flame retardancy of the material while maintaining the excellent mechanical properties of the silicone rubber. This results in a modified silicone rubber with both excellent flame retardant and mechanical properties, thereby broadening its application areas.

[0053] It should be noted that the value range of the vinyl silicone resin is "40 parts to 80 parts", which means the minimum and maximum value of the range of 40 parts to 80 parts, as well as every value between the minimum and maximum value. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, or 80 parts; or any range of any two of these values, for example, including: 40 parts to 60 parts.

[0054] The value range of the vinyl silicone oil is "30 parts to 60 parts", which means the minimum and maximum value of the range of 30 parts to 60 parts, as well as every value between the minimum and maximum value. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, or 60 parts; or any range of any two of these values, for example, including: 40 parts to 50 parts.

[0055] The value range for the non-active hydrogen-based MQ silicone resin is "10 parts to 20 parts", which means the minimum and maximum values ​​within the range of 10 parts to 20 parts, as well as every value between these minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts; or a range consisting of any two of these values, for example, including: 10 parts to 15 parts.

[0056] The value range of the vinyl cage-type polysilsesquioxane is "1 part to 5 parts", which means the minimum and maximum value of the range of 1 part to 5 parts, as well as every value between the minimum and maximum value. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 1 part, 2 parts, 3 parts, 4 parts or 5 parts; or a range of any two of these values, for example, including: 1 part to 3 parts.

[0057] The range of hydrogen-containing silicone oil is "10 parts to 50 parts", which means taking the minimum and maximum values ​​of the range of 10 parts to 50 parts, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, or 50 parts; or any range consisting of any two of these values, for example, including: 10 parts to 35 parts.

[0058] The value range of MQ silicone resin is "10 parts to 20 parts", which means the minimum and maximum value of the range of 10 parts to 20 parts, as well as every value between the minimum and maximum value. Specific examples include, but are not limited to, the point values ​​in the embodiments and the following point values: 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts; or any range consisting of any two of these values, for example, including: 10 parts to 15 parts.

[0059] The value range for vinyl-free cage-type polysilsesquioxane is "0 parts to 5 parts", which means the minimum and maximum values ​​of the range of 0 parts to 5 parts, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the examples and the following point values: 0 parts, 1 part, 2 parts, 3 parts, 4 parts, or 5 parts; or any range of any two of these values, for example, including: 1 part to 3 parts.

[0060] In some embodiments, based on the total mass of the first raw material in the preparation raw materials of silicone, the mass percentage of the modified nano-calcium fluoride is 1% to 10%. For example, the mass percentage of the modified nano-calcium fluoride can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0061] Understandably, this application uses a silane coupling agent to graft and modify calcium fluoride. On the one hand, after modification with the coupling agent, calcium fluoride is uniformly dispersed in the matrix and can form a continuous flame-retardant barrier at high temperatures, more effectively blocking heat transfer and oxygen diffusion. On the other hand, the silane coupling agent grafted onto the surface of calcium fluoride can act as a "molecular bridge" between the inorganic flame-retardant filler (calcium fluoride) and the organosilicon matrix, tightly connecting the inorganic filler and the organic matrix to prepare a calcium fluoride / organosilicon system with good mechanical properties and flame-retardant effect.

[0062] In some embodiments, the modified nano-calcium fluoride accounts for 1% to 5% of the total mass of the first raw material in the preparation raw materials of silicone.

[0063] By further controlling the ratio range of modified nano-calcium fluoride in the raw materials, the modified silicone rubber exhibits better overall mechanical properties, achieving a better balance between flame retardancy and mechanical stability.

[0064] In some embodiments, the particle size of the modified nano-calcium fluoride is 20nm~90nm. For example, the particle size of the modified nano-calcium fluoride can be 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm or 90nm.

[0065] In some embodiments, the mass ratio of the first raw material to the second raw material in the preparation raw materials of the above-mentioned silicone is 1:(0.5~1.5). As an example, the mass ratio of the first raw material to the second raw material can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5.

[0066] In some embodiments, the mass fraction of vinyl in the above-mentioned vinyl-containing silicone resin is 0.9% to 1.9%. For example, the mass fraction of vinyl can be 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, or 1.9%.

[0067] In some embodiments, the viscosity of the vinyl-containing silicone oil at 25°C is 300 cps to 10000 cps. For example, the viscosity of the vinyl-containing silicone oil at 25°C can be 300 cps, 800 cps, 1300 cps, 1800 cps, 2300 cps, 2800 cps, 3300 cps, 3800 cps, 4300 cps, 4800 cps, 5300 cps, 5800 cps, 6300 cps, 6800 cps, 7300 cps, 7800 cps, 8300 cps, 8800 cps, 9300 cps, 9800 cps, or 10000 cps.

[0068] In some embodiments, the mass fraction of hydrogen in the aforementioned hydrogen-containing silicone oil is 0.1% to 0.5%. For example, the mass fraction of hydrogen may be 0.1%, 0.2%, 0.3%, 0.4%, or 0.5%.

[0069] In some embodiments, the catalyst described above includes a platinum-type catalyst.

[0070] In some embodiments, the inhibitors described above include one or more of alkynyl alcohol inhibitors or silicone inhibitors.

[0071] Another embodiment of this application provides a method for preparing modified silicone, comprising the following steps: mixing the first raw material, the second raw material and the modified nano-calcium fluoride, curing, and preparing the modified silicone.

[0072] In some embodiments, the preparation method of the above-mentioned modified nano-calcium fluoride includes the following steps A to B.

[0073] Step A: Mix the calcium salt solution and the fluoride salt solution to carry out a co-precipitation reaction, collect the precipitate, and prepare calcium fluoride.

[0074] Step B: Mix the above-mentioned calcium fluoride, silane coupling agent and solvent to prepare modified nano-calcium fluoride.

[0075] In some embodiments, the concentration of calcium ions in the calcium salt solution is 0.05 mol / L to 0.15 mol / L. For example, the concentration can be 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, 0.10 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, or 0.15 mol / L.

[0076] In some embodiments, the fluoride ion concentration in the fluoride salt solution is 0.1 mol / L to 0.3 mol / L. For example, the concentration may be 0.10 mol / L, 0.12 mol / L, 0.14 mol / L, 0.16 mol / L, 0.18 mol / L, 0.20 mol / L, 0.22 mol / L, 0.24 mol / L, 0.26 mol / L, 0.28 mol / L, or 0.30 mol / L.

[0077] In some embodiments, the calcium salt in the above-mentioned calcium salt solution includes one or more of calcium chloride, calcium nitrate, calcium hydroxide, calcium oxide, and calcium carbonate.

[0078] In a specific example, the calcium salt in the above calcium salt solution is calcium chloride.

[0079] In some embodiments, the fluoride salt in the above-mentioned fluoride solution includes one or more of ammonium fluoride, sodium fluoride, potassium fluoride, and sodium fluorosilicate.

[0080] In a specific example, the fluoride salt in the above fluoride solution is ammonium fluoride.

[0081] In some of these embodiments, the concentration ratio of CaCl2 to NH4F is 1:2. It is understood that the addition of NH4F in slightly excess results in higher utilization of calcium chloride and increased yield of calcium fluoride.

[0082] In some embodiments, the precipitation reaction is carried out at a temperature of 20°C to 30°C for a time of 30 min to 120 min.

[0083] In some embodiments, the temperature for mixing the calcium fluoride, silane coupling agent, and solvent is 40°C to 60°C, and the time is 60 min to 240 min.

[0084] In some embodiments, the NH4F dropping rate in the above mixing process is controlled at 10 mL / min, and the stirring is relatively vigorous. This process makes it difficult for calcium fluoride to agglomerate during the formation process and ensures uniform particle size.

[0085] In some embodiments, the powder is further ground using a cell disruptor before being mixed into the first raw material of the organosilicon to increase the uniformity of its dispersion and prevent agglomeration.

[0086] In some embodiments, the mass ratio of the calcium fluoride to the silane coupling agent is 45 to 55:1; for example, it can be 45:1, 46:1, 47:1, 48:1, 49:1, 50:1, 51:1, 52:1, 53:1, 54:1 or 55:1.

[0087] In some embodiments, the silane coupling agent described above includes one or more of KH560, KH570, and KH550;

[0088] In some embodiments, the solvents mentioned above include one or more of ethanol, water, methanol, and isopropanol.

[0089] In some embodiments, the curing temperature is 70°C to 80°C and the time is 15 min to 240 min.

[0090] Furthermore, the modified silicone obtained by this method has good mechanical properties and flame retardant effect; and the preparation process of the modified silicone is simple, the raw materials are readily available, the cost is low, and the production adaptability is wide.

[0091] Another embodiment of this application provides a flame-retardant article comprising modified silicone as described above or modified silicone prepared by the above-described method.

[0092] Optionally, the flame-retardant products mentioned above include packaging materials for electronic and electrical appliances.

[0093] To make the objectives, technical solutions, and advantages of this application clearer and more concise, the following specific embodiments are used for illustration, but this application is by no means limited to these embodiments. The embodiments described below are merely preferred embodiments of this application and can be used to describe this application, but should not be construed as limiting the scope of this application. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

[0094] To better illustrate this application, the following description, in conjunction with embodiments, further explains the content of this application.

[0095] Example 1

[0096] (1) A CaCl2 solution containing 0.05 mol calcium ions and an NH4F solution containing 0.1 mol fluoride ions were co-precipitated at 25°C. The NH4F solution was added dropwise to the continuously stirred CaCl2 solution at a rate of 10 mL / min. After the addition was completed, the reaction continued for 30 min. The solution was then allowed to stand and age. The resulting precipitate was separated, washed and dried to obtain calcium fluoride powder.

[0097] (2) Prepare an ethanol solution of silane coupling agent (specifically KH560) with a concentration of 2.0 wt%. Add the calcium fluoride powder obtained in step (1) to the solution, with a mass ratio of calcium fluoride powder to silane coupling agent of 50:1. After ultrasonic dispersion for 1 h, the coupling agent is grafted onto the surface of the calcium fluoride. Then, the mixture is dried and ground to obtain modified nano-calcium fluoride with a particle size of 20 nm to 90 nm.

[0098] (3) Modified silicone includes silicone and modified nano-calcium fluoride distributed in the silicone. The silicone includes a first raw material and a second raw material in a mass ratio of 1:1.2. The first raw material, by mass, includes 60 parts of vinyl silicone resin (specifically, methyl vinyl silicone resin with a vinyl content of 1.5% and a viscosity of 8000 mPa·s), 25 parts of vinyl silicone oil (specifically, vinyl-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s at 25°C and a vinyl content of 0.06%), 10 parts of methyl MQ silicone resin without active hydrogen (specifically, methyl MQ silicone resin with an M:Q ratio of 1:1.0 and a viscosity of 60000 mPa·s), 3 parts of vinyl cage-type polysilsesquioxane (specifically, vinyl POSS with a vinyl mass fraction of 1.8%), and a catalyst (specifically, platinum-divinylsiloxane complex with a Pt content of 1000). The raw materials consist of 0.1 parts by mass of a first diluent (specifically, low-viscosity vinyl silicone oil with a viscosity of 100 mPa·s), 1.9 parts by mass of a second raw material, including 30 parts by mass of a hydrogen-containing silicone oil (specifically, end-hydrogen-containing polydimethylsiloxane with a hydrogen content of 0.3%), 15 parts by mass of a methyl hydrogen-containing MQ silicone resin (specifically, methyl hydrogen-containing MQ silicone resin with a hydrogen content of 0.3%), 1 part by mass of a vinyl-free cage-type polysilsesquioxane (specifically, octamethyl cage-type polysilsesquioxane with a purity ≥98%), an inhibitor (specifically, 0.12 parts by mass of a 1-ethynylcyclohexanol), and 73.88 parts by mass of a second diluent, 500 mPa·s dimethyl silicone oil; the modified nano-calcium fluoride accounts for 1% of the total mass of the first raw material in the preparation raw materials of the silicone.

[0099] The specific preparation steps of the modified organosilicon are as follows: a. Add the above-mentioned modified nano-calcium fluoride into the first raw material, add n-heptane into the beaker in sequence, treat with an ultrasonic cell disruptor at 600W for 20 minutes, place in a 90℃ oil bath, stir for 4 hours, and when the stirring is complete and there is no odor, the preparation is complete.

[0100] b. The first raw material and the second raw material with added filler are mixed in a ratio of 1:1.2 to remove air bubbles, and then baked in an oven at 70°C for 15 minutes to cure, thus preparing modified silicone.

[0101] Examples 2-7

[0102] Other examples 2-7 are basically the same as example 1, except that the raw materials used in preparation are different in Table 1. Please see Table 1 for details.

[0103] The other steps and conditions are the same as in Example 1.

[0104] Comparative Example 1

[0105] The preparation method of the modified organosilicone in Comparative Example 1 is basically the same as that in Example 1, except that modified nano-calcium fluoride is not added to the raw materials. The specific steps are as follows:

[0106] The first raw material and the second raw material are mixed in a ratio of 1:1.2 to remove bubbles, and then baked in an oven at 70°C for 15 minutes to cure, thus preparing modified silicone.

[0107] The other steps and conditions are the same as in Example 1.

[0108] Comparative Example 2

[0109] The preparation method of the modified silicone in Comparative Example 2 is basically the same as that in Example 1, except that the raw materials are different. Please refer to Table 1 for details.

[0110] The other steps and conditions are the same as in Example 1.

[0111] Comparative Example 3

[0112] The preparation method of the modified silicone in Comparative Example 3 is basically the same as that in Example 1, except that the preparation steps of the modified silicone are as follows:

[0113] (1) A CaCl2 solution containing 0.05 mol calcium ions and an NH4F solution containing 0.1 mol fluoride ions were co-precipitated at 25°C. The NH4F solution was added dropwise to the continuously stirred CaCl2 solution at a rate of 10 mL / min. After the addition was completed, the reaction continued for 30 min. The solution was then allowed to stand and age. The resulting precipitate was separated, washed and dried to obtain calcium fluoride powder.

[0114] (2) Add 5 parts of calcium fluoride and 0.1 parts of silane coupling agent obtained in step (1) into the first raw material, add n-heptane into the beaker in sequence, treat with an ultrasonic cell disruptor at 600W for 20 minutes, put into a 90℃ oil bath, stir for 4 hours, and when the stirring is complete and there is no odor, the preparation is complete.

[0115] (3) The first raw material and the second raw material with added filler are mixed in a ratio of 1:1.2 to remove bubbles, and then baked in an oven at 70°C for 15 minutes to cure, thus preparing modified silicone.

[0116] The other steps and conditions are the same as in Example 1.

[0117] Table 1

[0118]

[0119] Note: " / " indicates that the component does not exist.

[0120] The following are performance tests.

[0121] 1. Electron microscopy was used to observe the modified organosilicon prepared in each embodiment and comparative example;

[0122] 2. The heat release rate, total heat release, CO release rate, and total smoke release of the modified silicone rubber prepared in each example and comparative example were measured. Specifically, a cone calorimeter was used, and the test methods specified in international standard ISO 5660-1 were followed to measure the heat release rate (HRR), total heat release (THR), carbon monoxide (CO) release rate, and total smoke release (TSR) of the modified silicone rubber samples prepared in each example and comparative example. Before testing, the cone calorimeter was calibrated according to JJF 2068-2023 "Calibration Specification for Cone Calorimeter".

[0123] 3. Viscosity tests were performed on the different components of the modified silicone prepared in each embodiment and comparative example. Specifically, the viscosity of the first and second raw materials of the modified silicone prepared in each embodiment and comparative example was tested separately. The tests were conducted in accordance with the national standard GB / T 2794-2022 "Determination of Viscosity of Adhesives" using the single-cylinder rotational viscometer method (or cone-plate rotational viscometer method).

[0124] 4. The pull-out and shear strengths of the modified silicone rubbers prepared in each embodiment and comparative example were determined. Specifically, the adhesion performance was tested: single-lap shear specimens were prepared according to standard GB / T 7124-2008, and their tensile shear strength was determined using a universal testing machine. Simultaneously, their pull-out strength was determined using a pull-out tester according to ISO 4624:2016.

[0125] 5. The tensile strength and elongation at break of the modified silicone rubber prepared in each embodiment and comparative example were determined. Specifically, for the bulk mechanical property test: the cured silicone rubber was cut into type 2 dumbbell-shaped specimens according to GB / T 528-2009 standard. The specimens were tested using a universal testing machine at (23±2)℃ and a tensile speed of 500 mm / min, and the tensile strength and elongation at break were recorded. The results are shown in Tables 2 and 3.

[0126] Table 2

[0127]

[0128] Table 3

[0129]

[0130] Figure 1 The images show the SEM morphology and particle size distribution of the calcium fluoride nanomaterials obtained in Example 1. Figure 2To verify the heat release rate, total heat release, CO release rate, and total smoke release of the modified silicone rubber obtained in Examples 1-4 and Comparative Example 1 in the cone test, the amount of modified calcium fluoride added was positively correlated with the flame retardant performance. The heat release rate and total heat release were significantly reduced, and the smoke particle release was effectively suppressed. The addition of modified nano-calcium fluoride had no negative impact on the mechanical properties of the matrix. The best comprehensive mechanical properties were achieved at an addition amount of 5%, reaching the optimal balance between flame retardancy and mechanical stability.

[0131] As shown in Tables 2 and 3, compared with the comparative examples, the modified silicone prepared in the embodiments of this application has both excellent mechanical properties and flame retardant properties.

[0132] In summary, this application of modified nano-calcium fluoride for flame retardant modification of silicone rubber is expected to achieve good flame retardant effects at a relatively low addition amount, while maximizing the preservation of the excellent overall performance of the silicone matrix. This innovative approach provides a new technical route and theoretical basis for developing next-generation high-performance, environmentally friendly flame-retardant silicone composite materials.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A modified silicone rubber, characterized in that, The invention includes silicone rubber and modified nano-calcium fluoride distributed in the silicone rubber, wherein the modified nano-calcium fluoride includes nano-calcium fluoride modified with a silane coupling agent. The raw materials for preparing the silicone include a first raw material and a second raw material; The components of the first raw material, by mass parts, include: 40 to 80 parts of vinyl silicone resin, 30 to 60 parts of vinyl silicone oil, 10 to 20 parts of MQ silicone resin without active hydrogen, 1 to 5 parts of vinyl cage-type polysilsesquioxane, catalyst, and first diluent. The second raw material comprises, by weight parts: 10-50 parts of hydrogen-containing silicone oil, 10-20 parts of MQ silicone resin, 0-5 parts of vinyl-free cage-type polysilsesquioxane, inhibitor, and a second diluent; based on the total weight of the first raw material in the preparation raw materials of the organosilicon, the modified nano-calcium fluoride accounts for 1%-10% of the total weight. The modified nano-calcium fluoride has a particle size of 20nm~90nm.

2. The modified silicone rubber according to claim 1, characterized in that, In the raw materials for preparing the organosilicon, the mass ratio of the first raw material to the second raw material is 1:(0.5~1.5).

3. The modified silicone rubber according to any one of claims 1 to 2, characterized in that, In the vinyl-containing silicone resin, the mass fraction of vinyl groups is 0.9% to 1.9%. And / or, the viscosity of the vinyl silicone oil at 25°C is 300 cps to 10000 cps; And / or, in the hydrogen-containing silicone oil, the mass fraction of hydrogen is 0.1% to 0.5%; And / or, the catalyst comprises a platinum-type catalyst; And / or, the inhibitor includes one or more of alkynyl alcohol inhibitors or silicone inhibitors.

4. A method for preparing the modified organosilicone according to any one of claims 1 to 3, characterized in that, Includes the following steps: The first raw material, the second raw material, and the modified nano-calcium fluoride are mixed and cured to prepare the modified organosilicon.

5. The method for preparing modified organosilicone according to claim 4, characterized in that, The preparation method of the modified nano-calcium fluoride includes the following steps: A calcium salt solution and a fluoride salt solution were mixed to carry out a co-precipitation reaction, and the precipitate was collected to prepare calcium fluoride. Modified nano-calcium fluoride is prepared by mixing the calcium fluoride, silane coupling agent, and solvent.

6. The method for preparing modified organosilicone according to claim 5, characterized in that, The concentration of calcium ions in the calcium salt solution is 0.05 mol / L to 0.15 mol / L; And / or, the fluoride ion concentration in the fluoride salt solution is 0.1 mol / L to 0.3 mol / L; And / or, the calcium salt in the calcium salt solution includes one or more of calcium chloride, calcium nitrate, calcium hydroxide, calcium oxide, and calcium carbonate; And / or, the fluoride salt in the fluoride solution includes one or more of ammonium fluoride, sodium fluoride, potassium fluoride, and sodium fluorosilicate.

7. The method for preparing modified organosilicone according to claim 5, characterized in that, The precipitation reaction was carried out at a temperature of 20℃~30℃ for 30min~120min. And / or, the temperature for mixing the calcium fluoride, silane coupling agent and solvent is 40°C to 60°C, and the time is 60 min to 240 min; And / or, the curing temperature is 70℃~80℃, and the time is 15min~240min.

8. The method for preparing modified organosilicone according to claim 5, characterized in that, The silane coupling agent includes one or more of KH560, KH570 and KH550; And / or, the solvent includes one or more of ethanol, water, methanol and isopropanol.

9. The method for preparing modified organosilicone according to any one of claims 5 to 8, characterized in that, The mass ratio of the calcium fluoride to the silane coupling agent is 45~55:

1.

10. A flame-retardant product, characterized in that, The flame-retardant product includes modified silicone as described in any one of claims 1 to 3, or modified silicone prepared by any one of claims 4 to 9.

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