Fireproof silicone sealant for building

Abstract

The invention relates to the technical field of sealants, in particular to a silicone fireproof sealant for buildings. Quaternary ammonium salt modified silicone oil is added in the preparation process of a silicone sealant base adhesive, and a quaternary ammonium salt group is introduced through a ring-opening reaction of epoxy-terminated polyether and trimethylamine hydrochloride, so that a microbial cell membrane structure is destroyed, and broad-spectrum antibiosis is realized; chemical bonding of quaternary ammonium salt groups and a silicone oil main chain avoids the problem of migration failure of a traditional mildew preventive; secondly, the modified aluminum hydroxide can improve the flame retardant property of the sealant, after the aluminum hydroxide is modified by vinyl trimethoxy silane, the surface hydrophobicity of the sealant can be enhanced, the dispersity of the sealant in base glue is improved, the heat absorption efficiency is high during thermal decomposition, and the combustion speed can be delayed, so that the fireproof performance is improved; the modified aluminum hydroxide is combined with the melamine and the modified hollow glass beads for synergism, so that the prepared silicone fireproof sealant has excellent fireproof performance.

Description

Technical Field

[0001] The invention relates to the technical field of sealants, and in particular to a silicone fireproof sealant for construction. Background Art

[0002] In the modern construction industry, with the increasing requirements for fire safety, the application of fireproof sealing materials has become increasingly important. As a high-performance sealing material, silicone sealant is widely used in construction, automobiles, electronics and other fields due to its good weather resistance, chemical corrosion resistance and elasticity.

[0003] However, traditional silicone sealants have average fire resistance and are difficult to meet the high requirements of modern buildings for fireproof sealing materials. In order to improve the fire resistance of silicone sealants, technicians in this field have begun to explore modification methods such as adding flame retardants and inorganic fillers to silicone sealants. However, many flame retardants and inorganic fillers have poor compatibility with base glues, and are prone to uneven dispersion during the blending and modification process. Therefore, technicians in this field are in urgent need of designing a new silicone sealant that can improve its flame retardant properties while also improving its mechanical properties by improving the compatibility of fillers. Summary of the invention

[0004] Technical issues solved In view of the above-mentioned shortcomings of the prior art, the present invention provides a silicone fireproof sealant for construction, which can effectively solve the problem that the flame retardancy and mechanical properties of the silicone sealant in the prior art are not ideal.

[0005] Technical Solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A fireproof silicone sealant for construction, the fireproof silicone sealant for construction comprising the following components: silicone sealant base, modified hollow glass microspheres, vinyl tributyl ketone oxime, fumed silica, dibutyl tin dilaurate and silane coupling agent KH-550; The silicone sealant base is prepared with alpha, omega-dihydroxy polydimethylsiloxane, modified silica lime, quaternary ammonium salt modified silicone oil and compound flame retardant components as raw materials.

[0007] Furthermore, the preparation steps of the modified silica lime are: Step A, weighing 15-20 parts by weight of silica lime and adding it into 200 parts by weight of ethanol solution, mixing and dispersing in a water bath at 78° C., and the obtained solution is recorded as the dispersed component; Step B: Weigh 0.5 parts by weight of silane coupling agent KH-570 and add it to 15-20 parts by weight of ethanol solution. After mixing evenly, drop it into the dispersion component. After dropping, continue stirring at the original stirring speed for 40 min and perform ultrasonic treatment. After suction filtration, wash it 3-5 times with deionized water. After suction filtration again, place the obtained filter cake in an oven at 85 °C and dry it for 12 h. What is obtained is the modified silica lime.

[0008] Furthermore, the method of mixing and dispersing in Step A is to stir at a stirring speed of 500 r / min for 30 min. The mass fraction of the ethanol solution in both Step A and Step B is 80%. The method of mixing evenly in Step B is to stir at a stirring speed of 300 r / min for 30 min. The dropping speed in Step B is 2 drops / s. The ultrasonic treatment method in Step B is to perform ultrasonic dispersion at a frequency of 30 kHz for 30 min.

[0009] Furthermore, the preparation method of the quaternary ammonium salt modified silicone oil is as follows: Weigh 100 parts by weight of terminal epoxy polyether modified silicone oil and 30-50 parts by weight of ethylene glycol monobutyl ether and pour them into a flask. Stir at a stirring speed of 300 r / min for 10 min, then add 20-30 parts by weight of trimethylamine hydrochloride, and react under the water bath condition of 80 °C for 4-6 h. After the reaction is completed, cool down to room temperature. What is obtained is the quaternary ammonium salt modified silicone oil.

[0010] Furthermore, the compound flame retardant component is prepared by mixing modified aluminum hydroxide and melamine in a weight ratio of 2:1.

[0011] Furthermore, the preparation steps of the modified aluminum hydroxide are as follows: Weigh 5-10 parts by weight of aluminum hydroxide and add it to 80-100 parts by weight of absolute ethanol. Drop 1 part by weight of vinyltrimethoxysilane at a dropping speed of 1 drop / s. Stir and react at a stirring speed of 400 r / min under the water bath condition of 50 °C for 12 h. After filtering to remove the filtrate, wash it 3 times with absolute ethanol, place it in an oven at 80 °C and dry it to constant weight, and then grind it through a 200-mesh sieve. What is obtained is the modified aluminum hydroxide.

[0012] Furthermore, the preparation steps of the silicone sealant base glue are as follows: Step 1: Weigh 100 parts by weight of α,ω-dihydroxypolydimethylsiloxane and put it into a kneader and knead for 5 min. Then, successively add 70-80 parts by weight of modified silica lime, 30-40 parts by weight of quaternary ammonium salt modified silicone oil, and 40-50 parts by weight of compound flame retardant component. The interval between each feeding is 5 min and continue kneading during the interval. What is obtained is denoted as the mixed component; Step 2: Heat the kneader containing the mixed components to 120°C and knead under vacuum for 3 hours. Then, naturally cool it to room temperature under vacuum conditions. After grinding through a 200-mesh sieve, the obtained product is the base silicone sealant.

[0013] Furthermore, the preparation method of the modified hollow glass microspheres is as follows: Weigh 5 - 6 parts by weight of silane coupling agent KH-570 and add it to 10 - 15 parts by weight of absolute ethanol. After ultrasonic dispersion at a frequency of 28 kHz for 10 minutes, drop it into 15 - 20 parts by weight of hollow glass microspheres at a dropping rate of 2 drops / s. Stir at a stirring speed of 200 r / min for 30 - 50 minutes, then place it in an oven at 80°C and dry for 3 - 4 hours. After grinding through a 100-mesh sieve, the obtained product is the modified hollow glass microspheres.

[0014] Furthermore, the preparation method of the silicone fireproof sealant for building is as follows: Add 100 - 120 parts by weight of the base silicone sealant into a planetary mixer, stir under vacuum for 10 minutes, then add 20 - 22 parts by weight of vinyl tributanone oxime. Continue to stir under vacuum for 30 minutes, and then sequentially add 15 - 20 parts by weight of modified hollow glass microspheres, 10 - 15 parts by weight of fumed silica, 0.5 part by weight of dibutyltin dilaurate, and 5 - 8 parts by weight of silane coupling agent KH-550. After continuing to stir under vacuum for 30 minutes, the obtained product is the silicone fireproof sealant for building.

[0015] Furthermore, in the preparation method of the silicone fireproof sealant for building, the stirring speed of the vacuum stirring is 300 - 500 r / min.

[0016] Beneficial effects The present invention provides a silicone fireproof sealant for building. Compared with the existing well-known technologies, the present invention has the following beneficial effects: 1. In the preparation process of the base silicone sealant of the present invention, quaternary ammonium salt modified silicone oil is added. Through the ring-opening reaction of terminal epoxy polyether and trimethylamine hydrochloride, quaternary ammonium salt groups are introduced, thereby destroying the cell membrane structure of microorganisms and achieving broad-spectrum antibacterial. Moreover, the chemical bonding of quaternary ammonium salt groups with the silicone oil main chain avoids the problem of migration failure of traditional mildew-proof agents. Secondly, the modified aluminum hydroxide in the present invention can improve the flame retardant performance of the sealant. After being modified by vinyltrimethoxysilane, the surface hydrophobicity of aluminum hydroxide is enhanced, and its dispersibility in the base glue is improved. When it decomposes by heat, the heat absorption efficiency is relatively high, which can delay the combustion speed, thereby improving the fireproof performance. The synergism among the modified aluminum hydroxide, melamine, and modified hollow glass microspheres can enable the prepared silicone fireproof sealant to have excellent fireproof performance, effectively prevent the spread of fire in a high-temperature environment, and protect the safety of building structures.

[0017] 2. The present invention improves the mechanical properties and durability by introducing fumed silica and modified silica lime. The fumed silica provides nano-scale reinforcement, and the modified silica lime grafts silanol groups through a silane coupling agent, which can enhance the compatibility with the base rubber, thereby improving the tensile strength. The present invention uses ethanol as the modification solvent, which can achieve an environmental protection effect, and through a stepwise vacuum kneading process, bubble defects can be avoided and the filler dispersion uniformity can be improved. Detailed Embodiments

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] The present invention will be further described below in conjunction with embodiments.

[0020] The sources of some components in the examples and comparative examples are as follows: Silica lime, Hubei Jingjing Calcium Industry Co., Ltd.; Silane coupling agent KH-570, industrial grade, Hubei New Blue Sky New Materials Co., Ltd.; Terminal epoxy polyether modified silicone oil, industrial grade, Sheyang Tianyuan Chemical Co., Ltd.; Ethylene glycol monobutyl ether, industrial grade, Jiangsu Tianyin Chemical Co., Ltd.; Trimethylamine hydrochloride, industrial grade, Shanghai Aladdin Biochemical Technology Co., Ltd.; Aluminum hydroxide, analytical pure, Langfang Pengcai Fine Chemical Co., Ltd.; Vinyltrimethoxysilane, Shandong Duoju Chemical Co., Ltd.; Melamine, industrial grade, Jinan Shengda Chemical Co., Ltd.; α,ω-Dihydroxy polydimethylsiloxane, 107 rubber, viscosity 20 Pa·s, Hesheng Silicon Industry Co., Ltd.; Hollow glass microspheres, Shijiazhuang Runbang New Materials Technology Co., Ltd.; Vinyl triketoxime, industrial grade, Hubei New Blue Sky New Materials Co., Ltd.; Fumed silica, R106, specific surface area 300m 2 ·g -1 , Evonik Degussa (China) Investment Co., Ltd.; Dibutyltin dilaurate, industrial grade, Hubei New Blue Sky New Materials Co., Ltd.; Silane coupling agent KH-550, industrial grade, Hubei New Blue Sky New Materials Co., Ltd.;

[0021] Example 1 A silicone fireproof sealant for construction in this example, the silicone fireproof sealant for construction is composed of the following components: silicone sealant base rubber, modified hollow glass microspheres, vinyl tributanone oxime, fumed silica, dibutyltin dilaurate and silane coupling agent KH-550; The silicone sealant base rubber is prepared from raw materials including α,ω-dihydroxypolydimethylsiloxane, modified silica lime, quaternary ammonium salt modified silicone oil and compound flame retardant components.

[0022] The preparation steps of the modified silica lime are as follows: Step A: Weigh 15 parts by weight of silica lime and add it into 200 parts by weight of ethanol solution with a mass fraction of 80% each. Stir at a stirring speed of 500 r / min under the water bath condition of 78 °C for 30 min, and the obtained is recorded as the dispersion component; Step B: Weigh 0.5 part by weight of silane coupling agent KH-570 and add it into 15 parts by weight of ethanol solution with a mass fraction of 80% each. Stir at a stirring speed of 300 r / min for 30 min, then drop it into the dispersion component at a dropping speed of 2 drops / s. After dropping, continue to stir at the original stirring speed for 40 min and perform ultrasonic dispersion at a frequency of 30 kHz for 30 min. After suction filtration, wash it 3 times with deionized water, and after suction filtration again, place the obtained filter cake in an oven at 85 °C and dry it for 12 h. The obtained is the modified silica lime.

[0023] The preparation method of the quaternary ammonium salt modified silicone oil is as follows: Weigh 100 parts by weight of epoxy-terminated polyether modified silicone oil and 30 parts by weight of ethylene glycol monobutyl ether and pour them into a flask. Stir at a stirring speed of 300 r / min for 10 min, then add 20 parts by weight of trimethylamine hydrochloride, and react under the water bath condition of 80 °C for 4 h. After the reaction is completed, cool down to room temperature. The obtained is the quaternary ammonium salt modified silicone oil.

[0024] The compound flame retardant component is prepared by mixing modified aluminum hydroxide and melamine in a weight ratio of 2:1.

[0025] The preparation steps of the modified aluminum hydroxide are as follows: Weigh 5 parts by weight of aluminum hydroxide and add it into 80 parts by weight of absolute ethanol. Drop 1 part by weight of vinyltrimethoxysilane at a dropping speed of 1 drop / s, and stir and react at a stirring speed of 400 r / min under the water bath condition of 50 °C for 12 h. After filtering to remove the filtrate, wash it 3 times with absolute ethanol, place it in an oven at 80 °C and dry it to constant weight, and then grind it through a 200-mesh sieve. The obtained is the modified aluminum hydroxide.

[0026] The preparation steps of the silicone sealant base rubber are as follows: Step 1: Weigh 100 parts by weight of α,ω-dihydroxypolydimethylsiloxane and pour it into a kneader for kneading for 5 min. Then, successively add 70 parts by weight of modified silica lime, 30 parts by weight of quaternary ammonium salt modified silicone oil, and 40 parts by weight of compound flame retardant component. The feeding interval is 5 min each time, and kneading continues during the interval. The obtained product is denoted as the mixed component; Step 2: Heat the kneader containing the mixed component to 120 °C and conduct vacuum kneading for 3 h. Then, naturally cool it to room temperature under vacuum conditions. After grinding through a 200-mesh sieve, the obtained product is the base rubber of silicone sealant.

[0027] The preparation method of modified hollow glass microspheres is as follows: Weigh 5 parts by weight of silane coupling agent KH-570 and add it to 10 parts by weight of absolute ethanol. After ultrasonic dispersion at a frequency of 28 kHz for 10 min, it is dropped into 15 parts by weight of hollow glass microspheres at a dropping rate of 2 drops / s. After stirring at a stirring speed of 200 r / min for 30 min, it is placed in an oven at 80 °C for drying for 3 h. After grinding through a 100-mesh sieve, the obtained product is the modified hollow glass microspheres.

[0028] The preparation method of silicone fireproof sealant for building is as follows: Add 100 parts by weight of the base rubber of silicone sealant to a planetary mixer. After vacuum stirring for 10 min, add 20 parts by weight of vinyl tributanone oxime. After continuing vacuum stirring for 30 min, successively add 15 parts by weight of modified hollow glass microspheres, 10 parts by weight of fumed silica, 0.5 part by weight of dibutyltin dilaurate, and 5 parts by weight of silane coupling agent KH-550. After continuing vacuum stirring for 30 min, the obtained product is the silicone fireproof sealant for building, and the stirring speed of vacuum stirring is 300 r / min.

[0029] Example 2 A silicone fireproof sealant for building in this example is composed of the following components: the base rubber of silicone sealant, modified hollow glass microspheres, vinyl tributanone oxime, fumed silica, dibutyltin dilaurate, and silane coupling agent KH-550; The base rubber of silicone sealant is prepared from α,ω-dihydroxypolydimethylsiloxane, modified silica lime, quaternary ammonium salt modified silicone oil, and compound flame retardant component as raw materials.

[0030] The preparation steps of modified silica lime are as follows: Step A: Weigh 20 parts by weight of silica lime and add it to 200 parts by weight of ethanol solution with a mass fraction of 80% each. Stir at a stirring speed of 500 r / min under the water bath condition of 78 °C for 30 min. The obtained product is denoted as the dispersed component; Step B: Weigh 0.5 parts by weight of silane coupling agent KH-570 and add it to 20 parts by weight of an ethanol solution with a mass fraction of 80%. Stir at a stirring speed of 300 r / min for 30 min, then drop it into the dispersion component at a dropping speed of 2 drops / s. After dropping, continue to stir at the original stirring speed for 40 min and ultrasonically disperse at a frequency of 30 kHz for 30 min. After suction filtration, wash it 5 times with deionized water. After suction filtration again, place the obtained filter cake in an oven at 85°C and dry it for 12 h. What is obtained is the modified silicon lime.

[0031] The preparation method of quaternary ammonium salt modified silicone oil is as follows: Weigh 100 parts by weight of epoxy-terminated polyether modified silicone oil and 50 parts by weight of ethylene glycol monobutyl ether and pour them into a flask. Stir at a stirring speed of 300 r / min for 10 min, then add 30 parts by weight of trimethylamine hydrochloride, and react under the water bath condition of 80°C for 6 h. After the reaction is completed, cool down to room temperature. What is obtained is the quaternary ammonium salt modified silicone oil.

[0032] The compound flame retardant component is prepared by mixing modified aluminum hydroxide and melamine in a weight ratio of 2:1.

[0033] The preparation steps of modified aluminum hydroxide are as follows: Weigh 10 parts by weight of aluminum hydroxide and add it to 100 parts by weight of absolute ethanol. Drop 1 part by weight of vinyltrimethoxysilane at a dropping speed of 1 drop / s, and stir and react at a stirring speed of 400 r / min under the water bath condition of 50°C for 12 h. After filtering to remove the filtrate, wash it 3 times with absolute ethanol, place it in an oven at 80°C and dry it to constant weight, then grind it through a 200-mesh sieve. What is obtained is the modified aluminum hydroxide.

[0034] The preparation steps of the silicone sealant base glue are as follows: Step 1: Weigh 100 parts by weight of α,ω-dihydroxypolydimethylsiloxane and put it into a kneader and knead for 5 min. Then, successively add 80 parts by weight of modified silicon lime, 40 parts by weight of quaternary ammonium salt modified silicone oil and 50 parts by weight of compound flame retardant component. The feeding interval is 5 min each time and continue to knead during the interval. What is obtained is recorded as the mixed component; Step 2: Heat the kneader containing the mixed component to 120°C and vacuum knead for 3 h. Then, naturally cool it to room temperature under vacuum conditions, and grind it through a 200-mesh sieve. What is obtained is the silicone sealant base glue.

[0035] The preparation method of modified hollow glass microspheres is as follows: Weigh 6 parts by weight of silane coupling agent KH-570 and add it to 15 parts by weight of absolute ethanol. After ultrasonic dispersion at a frequency of 28 kHz for 10 min, it is dropped into 20 parts by weight of hollow glass microspheres at a dropping rate of 2 drops / s. After stirring at a stirring speed of 200 r / min for 50 min, it is placed in an oven at 80 °C and dried for 4 h. After grinding through a 100-mesh sieve, the obtained product is the modified hollow glass microspheres.

[0036] The preparation method of the silicone fireproof sealant for building is as follows: Add 120 parts by weight of silicone sealant base rubber into a planetary mixer, stir under vacuum for 10 min, then add 22 parts by weight of vinyl tributanone oxime, continue to stir under vacuum for 30 min, and then add 20 parts by weight of modified hollow glass microspheres, 15 parts by weight of fumed silica, 0.5 part by weight of dibutyltin dilaurate and 8 parts by weight of silane coupling agent KH-550 in sequence. After continuing to stir under vacuum for 30 min, the obtained product is the silicone fireproof sealant for building, and the stirring speed of the vacuum stirring is 500 r / min.

[0037] Example 3 A silicone fireproof sealant for building in this example is composed of the following components: silicone sealant base rubber, modified hollow glass microspheres, vinyl tributanone oxime, fumed silica, dibutyltin dilaurate and silane coupling agent KH-550; The silicone sealant base rubber is prepared from α,ω-dihydroxypolydimethylsiloxane, modified silica lime, quaternary ammonium salt modified silicone oil and a compound flame retardant component as raw materials.

[0038] The preparation steps of the modified silica lime are as follows: Step A: Weigh 18 parts by weight of silica lime and add it to 200 parts by weight of ethanol solution with a mass fraction of 80%. Stir at a stirring speed of 500 r / min under the water bath condition of 78 °C for 30 min, and the obtained product is recorded as the dispersion component; Step B: Weigh 0.5 part by weight of silane coupling agent KH-570 and add it to 17 parts by weight of ethanol solution with a mass fraction of 80%. After stirring at a stirring speed of 300 r / min for 30 min, it is dropped into the dispersion component at a dropping rate of 2 drops / s. After dropping, continue to stir at the original stirring speed for 40 min and ultrasonic disperse at a frequency of 30 kHz for 30 min. After suction filtration, wash it 4 times with deionized water, and after suction filtration again, place the obtained filter cake in an oven at 85 °C and dry it for 12 h. The obtained product is the modified silica lime.

[0039] The preparation method of the quaternary ammonium salt modified silicone oil is as follows: Weigh 100 parts by weight of the epoxy-terminated polyether modified silicone oil and 40 parts by weight of ethylene glycol monobutyl ether and pour them into a flask. Stir at a stirring speed of 300 r / min for 10 min, then add 25 parts by weight of trimethylamine hydrochloride, and react under a water bath condition of 80 °C for 5 h. After the reaction is completed, cool down to room temperature, and the obtained product is the quaternary ammonium salt modified silicone oil.

[0040] The composite flame retardant component is prepared by mixing modified aluminum hydroxide and melamine in a weight ratio of 2:1.

[0041] The preparation steps of the modified aluminum hydroxide are as follows: Weigh 8 parts by weight of aluminum hydroxide and add it to 90 parts by weight of absolute ethanol. Dropwise add 1 part by weight of vinyltrimethoxysilane at a dropping rate of 1 drop / s, and stir and react at a stirring speed of 400 r / min under a water bath condition of 50 °C for 12 h. After filtering to remove the filtrate, wash it 3 times with absolute ethanol, place it in an oven at 80 °C and dry to constant weight, then grind it through a 200-mesh sieve, and the obtained product is the modified aluminum hydroxide.

[0042] The preparation steps of the base rubber of silicone sealant are as follows: Step 1: Weigh 100 parts by weight of α,ω-dihydroxypolydimethylsiloxane and pour it into a kneader and knead for 5 min. Then, successively add 75 parts by weight of modified silica lime, 35 parts by weight of the quaternary ammonium salt modified silicone oil, and 45 parts by weight of the composite flame retardant component. The feeding interval is 5 min each time, and continue to knead during the interval. The obtained product is denoted as the mixed component; Step 2: Heat the kneader containing the mixed component to 120 °C and vacuum knead for 3 h, then naturally cool to room temperature under vacuum conditions, and grind it through a 200-mesh sieve. The obtained product is the base rubber of silicone sealant.

[0043] The preparation method of the modified hollow glass microspheres is as follows: Weigh 5 parts by weight of silane coupling agent KH-570 and add it to 13 parts by weight of absolute ethanol. Ultrasonically disperse it at a frequency of 28 kHz for 10 min, then dropwise add it into 17 parts by weight of hollow glass microspheres at a dropping rate of 2 drops / s, stir at a stirring speed of 200 r / min for 40 min, then place it in an oven at 80 °C and dry for 4 h, and grind it through a 100-mesh sieve. The obtained product is the modified hollow glass microspheres.

[0044] The preparation method of the silicone fireproof sealant for building is as follows: Add 110 parts by weight of the silicone sealant base gum into a planetary mixer. After vacuum stirring for 10 min, add 21 parts by weight of vinyl tributanone oxime. After continuing vacuum stirring for 30 min, add 18 parts by weight of modified hollow glass microspheres, 12 parts by weight of fumed silica, 0.5 part by weight of dibutyltin dilaurate and 7 parts by weight of silane coupling agent KH-550 in sequence. What is obtained after continuing vacuum stirring for 30 min is the silicone fireproof sealant for buildings, and the stirring speed of the vacuum stirring is 400 r / min.

[0045] Comparative Example 1 A silicone fireproof sealant for buildings provided in this comparative example is substantially the same as that in Example 1, and the main difference is that: in this Comparative Example 1, the modified silica lime in Example 1 is replaced with unmodified silica lime.

[0046] Comparative Example 2 A silicone fireproof sealant for buildings provided in this comparative example is substantially the same as that in Example 1, and the main difference is that: in this Comparative Example 2, the quaternary ammonium salt modified silicone oil in Example 1 is replaced with unmodified silicone oil.

[0047] Comparative Example 3 A silicone fireproof sealant for buildings provided in this comparative example is substantially the same as that in Example 1, and the main difference is that: in this Comparative Example 3, the compound flame retardant component in Example 1 is replaced with unmodified aluminum hydroxide.

[0048] Performance Test Label the silicone fireproof sealants for buildings prepared in Examples 1-3 and Comparative Examples 1-3 as Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 respectively, and then detect the performances of Examples 1-3 and Comparative Examples 1-3. The specific detection methods and detection items are as follows: 1. Refer to the standard of GB / T528-1998 to detect the tensile properties of Examples 1-3 and Comparative Examples 1-3 on a tensile testing machine, and record the obtained data in the following table; 2. Refer to the standard of GB / T531-1999 to detect the Shore hardness of Examples 1-3 and Comparative Examples 1-3, and record the obtained data in the following table; 3. Refer to the standard of GB / T10707-1989 to detect the limiting oxygen index of Examples 1-3 and Comparative Examples 1-3, and record the obtained data in the following table;

[0049] It can be seen from the data in the above table that the mechanical properties of the silicone fireproof sealant for building in Examples 1-3 are significantly better than those in Comparative Examples 1-2, indicating that adding modified silica lime and quaternary ammonium salt modified silicone oil in the preparation of the silicone fireproof sealant for building can improve the mechanical properties of the sealant. The limiting oxygen index of the silicone fireproof sealant for building in Comparative Example 3 is significantly lower than that in Examples 1-3, indicating that the synergistic effect of modified aluminum hydroxide and melamine can significantly improve the flame retardancy of the sealant.

[0050] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A silicone fireproof sealant for construction, characterized in that: The fireproof silicone sealant for construction is composed of the following components: silicone sealant base, modified hollow glass microspheres, vinyl trisbutyl ketone oxime, fumed silica, dibutyl tin dilaurate and silane coupling agent KH-550; The silicone sealant base is prepared with alpha, omega-dihydroxy polydimethylsiloxane, modified silica lime, quaternary ammonium salt modified silicone oil and compound flame retardant components as raw materials.

2. A fireproof silicone sealant for construction according to claim 1, characterized in that: The preparation steps of the modified silica lime are: Step A, weighing 15-20 parts by weight of silica lime and adding it into 200 parts by weight of ethanol solution, mixing and dispersing in a water bath at 78° C., and the obtained solution is recorded as the dispersed component; Step B, weigh 0.5 parts by weight of silane coupling agent KH-570 and add it to 15-20 parts by weight of ethanol solution, mix well and then drop it into the dispersed components, continue stirring at the original stirring speed for 40 minutes and perform ultrasonic treatment, filter and wash with deionized water for 3-5 times, filter again and place the filter cake in an oven at 85°C to dry for 12 hours, and the resulting modified silica lime is obtained.

3. A fireproof silicone sealant for construction according to claim 2, characterized in that: The mixing and dispersing method in step A is stirring at a stirring speed of 500 r / min for 30 min, the mass fraction of the ethanol solution in step A and step B is 80%, the uniform mixing method in step B is stirring at a stirring speed of 300 r / min for 30 min, the dripping rate in step B is 2 drops / s, and the ultrasonic treatment method in step B is ultrasonic dispersion at a frequency of 30 kHz for 30 min.

4. A fireproof silicone sealant for construction according to claim 1, characterized in that: The preparation method of the quaternary ammonium salt modified silicone oil is: Weigh 100 parts by weight of epoxy-terminated polyether-modified silicone oil and 30-50 parts by weight of ethylene glycol monobutyl ether into a flask, stir at a stirring speed of 300 r / min for 10 minutes, then add 20-30 parts by weight of trimethylamine hydrochloride, react in a water bath at 80°C for 4-6 hours, and cool to room temperature after the reaction is completed to obtain quaternary ammonium salt-modified silicone oil.

5. The fireproof silicone sealant for construction according to claim 1, characterized in that: The composite flame retardant component is prepared by mixing modified aluminum hydroxide and melamine in a weight ratio of 2:

1.

6. A fireproof silicone sealant for construction according to claim 5, characterized in that: The preparation steps of the modified aluminum hydroxide are: Weigh 5-10 parts by weight of aluminum hydroxide and add it to 80-100 parts by weight of anhydrous ethanol, add 1 part by weight of vinyltrimethoxysilane at a dropping rate of 1 drop / s, stir and react for 12 hours at a stirring speed of 400r / min in a water bath at 50°C, filter and remove the filtrate, wash with anhydrous ethanol for 3 times, place in an oven at 80°C to dry to constant weight, and then grind through a 200-mesh sieve to obtain modified aluminum hydroxide.

7. The fireproof silicone sealant for construction according to claim 1, characterized in that: The preparation steps of the silicone sealant base are as follows: Step 1, weighing 100 parts by weight of α, ω-dihydroxy polydimethylsiloxane into a kneader and kneading for 5 minutes, then adding 70-80 parts by weight of modified silica lime, 30-40 parts by weight of quaternary ammonium salt modified silicone oil and 40-50 parts by weight of composite flame retardant components in sequence, each addition interval is 5 minutes and kneading is continued during the interval, and the result is recorded as a mixed component; Step 2: Heat the kneader containing the mixed components to 120° C. and knead in vacuum for 3 hours, then naturally cool to room temperature under vacuum conditions, and grind through a 200-mesh sieve to obtain the silicone sealant base.

8. The fireproof silicone sealant for construction according to claim 1, characterized in that: The preparation method of the modified hollow glass microspheres is as follows: Weigh 5-6 parts by weight of silane coupling agent KH-570 and add it to 10-15 parts by weight of anhydrous ethanol. After ultrasonic dispersion at a frequency of 28kHz for 10 minutes, drip it into 15-20 parts by weight of hollow glass microspheres at a dripping rate of 2 drops / s. After stirring at a stirring speed of 200r / min for 30-50min, place it in an oven at 80°C and dry it for 3-4h. Grind it through a 100-mesh sieve to obtain the modified hollow glass microspheres.

9. A fireproof silicone sealant for construction according to claim 8, characterized in that: The preparation method of the silicone fireproof sealant for construction is: 100-120 parts by weight of silicone sealant base is added into a planetary mixer, and after vacuum stirring for 10 minutes, 20-22 parts by weight of vinyl trisbutyl ketone oxime is added, and after continuing vacuum stirring for 30 minutes, 15-20 parts by weight of modified hollow glass microspheres, 10-15 parts by weight of fumed silica, 0.5 parts by weight of dibutyl tin dilaurate and 5-8 parts by weight of silane coupling agent KH-550 are added in sequence, and vacuum stirring is continued for 30 minutes to obtain a silicone fireproof sealant for construction.

10. A fireproof silicone sealant for construction according to claim 9, characterized in that: In the preparation method of silicone fireproof sealant for construction, the stirring speed of vacuum stirring is 300-500r / min.

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