Environment-friendly high-temperature nano heat insulation plate with good heat insulation performance and preparation method thereof

Abstract

The invention discloses an environment-friendly high-temperature good-heat-insulation nanometer heat insulation plate and a preparation method thereof, and relates to the technical field of heat insulation plate preparation, and the preparation method comprises the following steps: uniformly stirring modified nanometer silicon dioxide aerogel, an opacifying agent and short fibers to obtain a mixture, feeding the mixture into a mold of a pressing machine, pressing into a plate, and drying to obtain the environment-friendly high-temperature good-heat-insulation nanometer heat insulation plate. After the plate is stripped from the mold, absorbing redundant dust; feeding the pressed plate into a surface treatment workshop, coating a layer of self-skinning material on the surface of the plate, and skinning to obtain the environment-friendly high-temperature nano heat insulation plate with good heat insulation; cutting the obtained environment-friendly high-temperature nano heat insulation plate with good heat insulation into a specified size; and packaging the nano-plate with the specified size by using a polymeric membrane material to obtain a final product. The modified nano-silica aerogel is prepared from the following raw materials: hydroxyl silicone oil modified macroporous nano-silica aerogel, a tackifying modifier and a coupling agent. The nanometer heat insulation plate provided by the invention has excellent heat insulation performance and breaking strength.

Description

Technical Field

[0001] The present application relates to the field of heat insulation board preparation technology, and in particular to an environmentally friendly high-temperature heat insulation good nano heat insulation board and a preparation method thereof. Background Art

[0002] At present, the production processes of nano heat insulation boards are mainly divided into two types: dry pressing forming and wet pressing forming. Although the dry pressing forming process is simple, there are many problems: the flexural strength of the product is relatively low, and it is easy to be damaged during the cutting process, resulting in a low finished product rate. In addition, a large amount of dust (including silica, fibers, light-shielding agents, etc.) will be generated during the vacuum packaging process of the products formed by dry pressing. These dusts not only pollute the environment but also seriously affect the physical health of employees, resulting in an insufficiently environmentally friendly processing process.

[0003] Although the wet pressing forming process solves the flexural strength problem of the dry pressing forming process to a certain extent, making the product not easily damaged during the cutting process and significantly improving the finished product rate, this process also has obvious drawbacks, that is, the wet pressing forming process requires the addition of high-temperature adhesives. Since the thermal conductivity of high-temperature adhesives is usually high, this not only increases the production cost but also significantly reduces the high-temperature heat insulation performance of the product.

[0004] Therefore, developing a nano heat insulation board with excellent high-temperature heat insulation performance, environmental protection, and high efficiency, as well as its preparation technology, has become an urgent problem to be solved in the current industry. Summary of the Invention

[0005] In order to solve the problems in the prior art, the present application provides an environmentally friendly high-temperature heat insulation good nano heat insulation board and a preparation method thereof.

[0006] A preparation method of an environmentally friendly high-temperature heat insulation good nano heat insulation board provided by the present application adopts the following technical scheme:

[0007] A preparation method of an environmentally friendly high-temperature heat insulation good nano heat insulation board includes the following steps:

[0008] S1. Stir the modified nano silica aerogel, light-shielding agent, and short fibers evenly to obtain a mixture. Feed the mixture into the mold of a press and press it into a plate at 100 - 120 °C and 4.41 - 15.68 MPa. After the plate is taken out of the mold, suck away the excess dust;

[0009] S2. Feed the pressed plate into the surface treatment workshop and coat a self-skinning material on the surface of the plate. After skinning, an environmentally friendly high-temperature heat insulation good nano heat insulation board is obtained;

[0010] S3. Cut the obtained environmentally friendly high-temperature heat insulation good nano heat insulation board into specified sizes; after encapsulating the nano boards of specified sizes with a polymer film material, the final product is obtained;

[0011] The mass ratio of the modified nano-silica aerogel, light-shielding agent, and short fibers is 40-60:10-30:2-4;

[0012] The raw materials of the modified nano-silica aerogel include 99-99.5% of hydroxy silicone oil-modified nano-silica aerogel with large pore volume, 0.2-0.3% of tackifying modifier, and 0.3-0.7% of coupling agent by mass percentage.

[0013] Preferably, the hydroxy silicone oil-modified nano-silica aerogel with large pore volume is prepared from the following raw materials in parts by weight: 17-21 parts of sodium metasilicate pentahydrate, 900-1000 parts of water, 100-120 parts of water glass, 45-65 parts of dilute sulfuric acid, 0.005-0.007 parts of cetyltrimethylammonium bromide, and 5-15 parts of hydroxy silicone oil.

[0014] Preferably, the preparation method of the hydroxy silicone oil-modified nano-silica aerogel with large pore volume includes the following steps:

[0015] S1. Add sodium metasilicate pentahydrate to water, stir at a constant temperature of 80-90 °C, and simultaneously drop in water glass and dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 and when gelation occurs, then sequentially add cetyltrimethylammonium bromide and hydroxy silicone oil, keep warm for 2-4 h, and then adjust the pH to 3-4 to end the reaction to obtain wet nano-silica gel. Filter and wash it to obtain nano-silica filter cake;

[0016] S2. Dilute the above nano-silica filter cake with water, place it on a high-speed shear emulsifier, emulsify the nano-silica filter cake at 1500-2000 rpm for 15-20 min, and use an experimental spray dryer to dry the emulsified slurry with drying parameters of an air extraction frequency of 30-32 Hz, a feeding speed of 15-17 rpm, an atomization pressure of 0.3-0.5 MPa, an inlet temperature of 200-2 + 20 °C, and an outlet temperature of 105-115 °C to obtain nano-silica powder and pulverize it to obtain hydroxy silicone oil-modified nano-silica aerogel with large pore volume.

[0017] Preferably, the pore volume of the hydroxy silicone oil-modified nano-silica aerogel with large pore volume is 1.5-3 cm 3 / g.

[0018] Preferably, the tackifying modifier includes C5 resin, C9 resin, and silicon phosphate; the mass ratio of the C5 resin, C9 resin, and silicon phosphate is 1:0.8-1:0.9-1.1.

[0019] Preferably, the preparation method of the modified nano-silica aerogel includes the following steps:

[0020] After mixing the coupling agent and the tackifying modifier, add the hydroxy silicone oil modified macroporous nano - silica aerogel, and mix at a temperature of 120 - 160 °C and a rotation speed of 800 - 1000 rpm to obtain the modified nano - silica aerogel.

[0021] Preferably, the self - skinning material comprises component A and component B; the raw materials of component A by weight include 60 - 80 parts of polyether polyol, 20 - 40 parts of polymer polyol, 0.3 - 0.9 part of catalyst, 0.5 - 1.5 parts of foam stabilizer, 2 - 5 parts of chain extender, 0.1 - 1 part of short fiber, and 0.1 - 0.5 part of water; component B is modified isocyanate.

[0022] Preferably, the preparation method of the modified isocyanate comprises the following steps:

[0023] Heat the reactor to 40 - 60 °C, add 60 - 70 parts of isocyanate and 15 - 17 parts of hydroxy silicone oil by weight and stir evenly, raise the temperature to 70 - 80 °C and react for 2 - 4 h, evacuate the air, carry out vacuum distillation for 1 - 2 h to remove the unreacted substances, and obtain the modified isocyanate after cooling.

[0024] Preferably, the short fiber is one or more of glass fiber, alumina fiber, carbon fiber, and zirconia fiber; the length of the short fiber is 5 - 30 mm.

[0025] An environmentally friendly high - temperature heat - insulating nano - heat - insulating board provided by the present application adopts the following technical scheme:

[0026] [[ID=IS]]An environmentally friendly high - temperature heat - insulating nano - heat - insulating board, which is prepared according to the preparation method of the environmentally friendly high - temperature heat - insulating nano - heat - insulating board.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. By adopting the above - mentioned technical scheme, using sodium silicate as the silicon source and sulfuric acid as the precipitant, controlling the sol - gel process, regulating the structure of the nano - silica aerogel, and using hydroxy silicone oil with low thermal conductivity as the hydrophobic modifier to carry out in - situ alkylation modification on the synthesized gel, and through water washing, drying, and heat treatment, a nano - silica aerogel with a small apparent density and a large pore volume is obtained; it can effectively reduce the thermal conductivity of the nano - heat - insulating board and improve the heat - insulating effect, and at the same time can effectively enhance the strength of the nano - heat - insulating board and improve its flexural characteristics.

[0029] 2. By adopting the above technical solution, a layer of polyurethane integral skin material is coated on the surface of the nano heat insulation board. The integral skin material forms a tough protective film, effectively enhancing the surface strength and anti-bending ability of the nano heat insulation board, thus greatly improving the overall folding resistance performance of the product; by introducing short fibers and modifying with hydroxy silicone oil, the folding strength of the product can be further improved.

[0030] 3. By adopting the above technical solution, the nano heat insulation board provided by this application not only does not easily cause dust flying during the cutting and packaging processes, effectively improving the finished product rate, but also can effectively protect the environment and improve the physical health of employees. Specific embodiments

[0031] The following further elaborates on this application in conjunction with embodiments.

[0032] The chemical reagents used in the preparation examples, embodiment and comparative examples provided by the present invention are all commercially available products, and their brands and manufacturers are as follows:

[0033] C5 resin, Candice Chemical Industry (Hubei) Co., Ltd.

[0034] C9 resin, Candice Chemical Industry (Hubei) Co., Ltd.

[0035] Phosphosilicate, Jiangsu Pulosi Biotechnology Co., Ltd.

[0036] Sodium silicate, solid, Xinxiang Jinsha Chemical Industry Co., Ltd.

[0037] Sodium silicate, liquid, Hubei Chengfeng Chemical Industry Co., Ltd.

[0038] Hydroxy silicone oil, Anhui Aiyota Silicone Oil Co., Ltd.

[0039] Polyether polyol, Shenzhen Longdi Chemical Industry Co., Ltd., Dow polyether polyol VORANOL CP450 VORANOL 2070

[0040] Polymer polyol, Hubei Shiteng Chemical Technology Co., Ltd.

[0041] Polyurethane foam stabilizer, Shanghai Yexing Industrial Co., Ltd.

[0042] Preparation example 1

[0043] S1. Add 17 g of sodium silicate to 300 g of water, stir at a constant temperature of 80 °C, and simultaneously drop 100 g of water glass and 45 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until gel appears, then successively add 0.005 g of cetyltrimethylammonium bromide and 5 g of hydroxyl silicone oil, keep warm for 2 h, and then adjust the pH to 4 with 20% by mass dilute sulfuric acid to end the reaction, obtaining wet nano-silica gel. Filter and wash it to obtain nano-silica filter cake;

[0044] S2. Dilute the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier, and emulsify the nano-silica filter cake at 1500 rpm for 15 min. Dry the emulsified slurry with an experimental spray dryer under the drying parameters of an air extraction frequency of 30 Hz, a feeding speed of 15 rpm, an atomization pressure of 0.3 MPa, an inlet temperature of 200 °C, and an outlet temperature of 105 °C to obtain nano-silica powder, and use a flat grinding air flow pulverizer to pulverize it at a pulverizing pressure of 0.5 MPa, thus obtaining hydroxyl silicone oil modified nano-silica aerogel with a large pore volume; Detect that the pore volume of the hydroxyl silicone oil modified nano-silica aerogel with a large pore volume is 2.26 cm 3 / g according to GB / T 19587-2017 Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method;

[0045] S3. Mix 0.3 g of coupling agent and 0.2 g of tackifying modifier, add 99.5 g of hydroxyl silicone oil modified nano-silica aerogel with a large pore volume prepared in S2, and mix at a temperature of 120 °C and a rotation speed of 800 rpm for 1 h to obtain modified nano-silica aerogel;

[0046] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, with a mass ratio of 1:0.8:0.9.

[0047] Preparation Example 2

[0048] S1. Add 19 g of sodium silicate to 350 g of water, stir at a constant temperature of 85 °C, and simultaneously drop 110 g of water glass and 55 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until gel appears, then successively add 0.006 g of cetyltrimethylammonium bromide and 10 g of hydroxyl silicone oil, keep warm for 3 h, and then adjust the pH to 3.5 with 20% by mass dilute sulfuric acid to end the reaction, obtaining wet nano-silica gel. Filter and wash it to obtain nano-silica filter cake;

[0049] S2. After diluting the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 1750 rpm for 18 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced draft frequency of 31 Hz, a feeding speed of 16 rpm, an atomization pressure of 0.4 MPa, an inlet temperature of 210 °C, and an outlet temperature of 110 °C to obtain nano-silica powder. Then, use a flat grinding air classifier to crush it at a crushing pressure of 0.55 MPa to obtain hydroxy silicone oil-modified mesoporous nano-silica aerogel; Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxy silicone oil-modified mesoporous nano-silica aerogel is 2.35 cm 3 / g;

[0050] S3. After mixing 0.3 g of coupling agent and 0.2 g of tackifying modifier, add 99.5 g of the hydroxy silicone oil-modified mesoporous nano-silica aerogel prepared in S2, and mix at a temperature of 120 °C and a rotation speed of 800 rpm for 1 h to obtain the modified nano-silica aerogel;

[0051] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:0.8:0.9.

[0052] Preparation Example 3

[0053] S1. Add 19 g of sodium silicate to 400 g of water, stir at a constant temperature of 90 °C, and simultaneously drop in 120 g of water glass and 65 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until a gel appears, and then sequentially add 0.007 g of cetyltrimethylammonium bromide and 15 g of hydroxy silicone oil, keep warm for 4 h, and then adjust the pH to 3 with 20% by mass dilute sulfuric acid to end the reaction to obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake;

[0054] S2. After diluting the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 2000 rpm for 20 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced air frequency of 32 Hz, a feeding speed of 17 rpm, an atomization pressure of 0.5 MPa, an inlet temperature of 220 °C, and an outlet temperature of 115 °C to obtain nano-silica powder. Then, use a flat grinding air-flow pulverizer to pulverize it under a pulverizing pressure of 0.6 MPa to obtain the hydroxyl silicone oil-modified large-pore-volume nano-silica aerogel; refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxyl silicone oil-modified large-pore-volume nano-silica aerogel is 2.15 cm 3 / g;

[0055] S3. After mixing 0.3 g of coupling agent and 0.2 g of tackifying modifier, add 99.5 g of the hydroxyl silicone oil-modified large-pore-volume nano-silica aerogel prepared in S2, and mix at a temperature of 120 °C and a rotation speed of 800 rpm for 1 h to obtain the modified nano-silica aerogel;

[0056] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:0.8:0.9.

[0057] Preparation Example 4

[0058] S1. Add 17 g of sodium silicate to 300 g of water, stir at a constant temperature of 80 °C, and simultaneously drop 100 g of water glass and 45 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until a gel appears, then sequentially add 0.005 g of cetyltrimethylammonium bromide and 5 g of hydroxyl silicone oil, keep warm for 2 h, and then adjust the pH to 3-4 with 20% by mass dilute sulfuric acid to end the reaction to obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake;

[0059] S2. After diluting the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 1500 rpm for 15 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced draft frequency of 30 Hz, a feeding speed of 15 rpm, an atomization pressure of 0.3 MPa, an inlet temperature of 200 °C, and an outlet temperature of 105 °C to obtain nano-silica powder. Then, use a flat grinding air-flow pulverizer to pulverize it at a pulverizing pressure of 0.5 MPa to obtain hydroxy silicone oil-modified mesoporous nano-silica aerogel; refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxy silicone oil-modified mesoporous nano-silica aerogel is 2.26 cm 3 / g;

[0060] S3. After mixing 0.5 g of coupling agent and 0.25 g of tackifying modifier, add 99.25 g of the hydroxy silicone oil-modified mesoporous nano-silica aerogel prepared in S2, and mix at a temperature of 140 °C and a rotation speed of 900 rpm for 1.5 h to obtain modified nano-silica aerogel;

[0061] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:0.8:0.9.

[0062] Preparation Example 5

[0063] S1. Add 17 g of sodium silicate to 300 g of water, stir at a constant temperature of 80 °C, and simultaneously drop in 100 g of water glass and 45 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until a gel appears, and then sequentially add 0.005 g of cetyltrimethylammonium bromide and 5 g of hydroxy silicone oil, keep warm for 2 h, and then adjust the pH to 3-4 with 20% by mass dilute sulfuric acid to end the reaction to obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake;

[0064] S2. After diluting the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 1500 rpm for 15 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced draft frequency of 30 Hz, a feed rate of 15 rpm, an atomization pressure of 0.3 MPa, an inlet temperature of 200 °C, and an outlet temperature of 105 °C to obtain nano-silica powder. Then, use a flat grinding air flow pulverizer to pulverize it at a pulverization pressure of 0.5 MPa, and hydroxy silicone oil modified macroporous nano-silica aerogel is obtained. Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxy silicone oil modified macroporous nano-silica aerogel is 2.26 cm 3 / g;

[0065] S3. After mixing 0.7 g of coupling agent and 0.3 g of tackifying modifier, add 99 g of the hydroxy silicone oil modified macroporous nano-silica aerogel prepared in S2, and mix at a temperature of 160 °C and a rotation speed of 1000 rpm for 2 h to obtain modified nano-silica aerogel;

[0066] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:0.8:0.9.

[0067] Preparation Example 6

[0068] S1. Add 17 g of sodium silicate to 300 g of water, stir at a constant temperature of 80 °C, and simultaneously drop 100 g of water glass and 45 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until a gel appears, and then sequentially add 0.005 g of cetyltrimethylammonium bromide and 5 g of hydroxy silicone oil, keep warm for 2 h, and then adjust the pH to 4 with 20% by mass dilute sulfuric acid to end the reaction to obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake;

[0069] S2. After diluting the above nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 1500 rpm for 15 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced air frequency of 30 Hz, a feeding speed of 15 rpm, an atomization pressure of 0.3 MPa, an inlet temperature of 200 °C, and an outlet temperature of 105 °C to obtain nano-silica powder. Then, use a flat grinding air-flow pulverizer to pulverize it at a pulverization pressure of 0.5 MPa, and thus obtain hydroxy silicone oil-modified mesoporous nano-silica aerogel; Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxy silicone oil-modified mesoporous nano-silica aerogel is 2.26 cm 3 / g;

[0070] S3. After mixing 0.3 g of coupling agent and 0.2 g of tackifying modifier, add 99.5 g of the hydroxy silicone oil-modified mesoporous nano-silica aerogel prepared in S2, and mix at a temperature of 120 °C and a rotation speed of 800 rpm for 1 h to obtain modified nano-silica aerogel;

[0071] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:0.9:1.

[0072] Preparation Example 7

[0073] S1. Add 17 g of sodium silicate to 300 g of water, stir at a constant temperature of 80 °C, and simultaneously drop in 100 g of water glass and 45 g of 20% by mass dilute sulfuric acid. After the dropping is completed, adjust the pH to 7 with 4.2% by mass oxalic acid until gel appears, and then sequentially add 0.005 g of cetyltrimethylammonium bromide and 5 g of hydroxy silicone oil, keep warm for 2 h, and then adjust the pH to 4 with 20% by mass dilute sulfuric acid to end the reaction, obtaining nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake;

[0074] S2. After diluting the above-mentioned nano-silica filter cake with 600 g of water, place it on a high-speed shear emulsifier and emulsify the nano-silica filter cake at 1500 rpm for 15 min. Then, use an experimental spray dryer to dry the emulsified slurry under the drying parameters of an induced air frequency of 30 Hz, a feeding speed of 15 rpm, an atomization pressure of 0.3 MPa, an inlet temperature of 200 °C, and an outlet temperature of 105 °C to obtain nano-silica powder. Then, use a flat grinding jet mill to crush it at a crushing pressure of 0.5 MPa, and hydroxy silicone oil-modified mesoporous nano-silica aerogel is obtained. Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method" to detect that the pore volume of the hydroxy silicone oil-modified mesoporous nano-silica aerogel is 2.26 cm 3 / g;

[0075] S3. After mixing 0.3 g of coupling agent and 0.2 g of tackifying modifier, add 99.5 g of the hydroxy silicone oil-modified mesoporous nano-silica aerogel prepared in S2, and mix at a temperature of 120 °C and a rotation speed of 800 rpm for 1 h to obtain modified nano-silica aerogel;

[0076] The coupling agent used in this preparation example is silane coupling agent KH550; the tackifying modifiers used include C5 resin, C9 resin, and silicon phosphate, and the mass ratio is 1:1:1.1.

[0077] Example 1

[0078] S1. Stir 40 g of the modified nano-silica aerogel prepared in Preparation Example 1, 10 g of light-shielding agent, and 2 g of short fibers evenly to obtain a mixture. Then, send the mixture into the mold of a press and press it into a plate at 100 °C and 4.41 MPa. After the plate is taken out of the mold, suck off the excess dust. The light-shielding agent used in this example is silicon carbide; the short fibers used are glass fibers with a length of 5 - 30 mm;

[0079] S2. Send the pressed plate into the surface treatment workshop and coat a self-skinning material on the surface of the plate at a temperature of 55 °C, and the skin thickness is 0.01 mm. After skinning, an environmentally friendly high-temperature heat-insulating nano heat-insulating board is obtained. The preparation method of the skinning material used in this example is as follows:

[0080] Mix 60 g of polyether polyol, 20 g of polymer polyol, 0.3 g of catalyst triethylenediamine, 0.5 g of polyurethane foam stabilizer, 2 g of chain extender ethylene glycol, 0.1 g of short fibers, and 0.1 g of water to obtain Component A;

[0081] Heat the reactor to 40°C, add 60 g of isocyanate and 15 g of hydroxyl silicone oil, stir evenly, heat up to 70°C and react for 2 h, evacuate the air, and perform vacuum distillation for 1 h to remove unreacted substances. After cooling, the modified isocyanate is obtained;

[0082] Add 60 g of the modified isocyanate to Component A at 25°C; quickly stir for 5 s to obtain a self-skinning material; the short fibers used in this example are glass fibers with a length of 5 - 30 mm;

[0083] S3. Cut the obtained environmentally friendly high-temperature heat-insulating good nano heat-insulating board into specified dimensions; after encapsulating the nano board of the specified dimensions with a polymer film material, the final product is obtained.

[0084] Example 2

[0085] Stir 50 g of the modified nano-silica aerogel prepared in Preparation Example 1, 20 g of a light-shielding agent, and 3 g of short fibers evenly to obtain a mixture. Feed the mixture into the mold of a press and press it into a plate at 110°C and 9 MPa. After the plate is taken out of the mold, suck off the excess dust; the light-shielding agent used in this example is silicon carbide; the short fibers used are alumina fibers with a length of 5 - 30 mm;

[0086] Feed the pressed plate into the surface treatment workshop and coat a layer of self-skinning material on the surface of the plate at 60°C, with a skin thickness of 0.05 mm; after skinning, an environmentally friendly high-temperature heat-insulating good nano heat-insulating board is obtained; the preparation method of the skinning material used in this example is as follows:

[0087] Mix 70 g of polyether polyol, 30 g of polymer polyol, 0.6 g of catalyst triethylenediamine, 1 g of polyurethane foam stabilizer, 3.5 g of chain extender ethylene glycol, 0.5 g of short fibers, and 0.3 g of water to obtain Component A;

[0088] Heat the reactor to 50°C, add 65 g of isocyanate and 16 g of hydroxyl silicone oil, stir evenly, heat up to 75°C and react for 3 h, evacuate the air, and perform vacuum distillation for 1.5 h to remove unreacted substances. After cooling, the modified isocyanate is obtained;

[0089] Add 70 g of the modified isocyanate to Component A at 30°C; quickly stir for 8 s to obtain a self-skinning material; the short fibers used in this example are alumina fibers with a length of 5 - 30 mm;

[0090] S3. Cut the obtained environmentally friendly high-temperature heat-insulating good nano heat-insulating board into specified dimensions; after encapsulating the nano board of the specified dimensions with a polymer film material, the final product is obtained.

[0091] Example 3

[0092] S1. Mix 60 g of the modified nano-silica aerogel prepared in Preparation Example 1, 30 g of a light-shielding agent, and 4 g of short fibers evenly to obtain a mixed material. Feed the mixed material into the mold of a press and press it into a plate at 120 °C and 15.68 MPa. After the plate is removed from the mold, suck off the excess dust. The light-shielding agent used in this example is silicon carbide; the short fibers used are carbon fibers and zirconia fibers with a length of 5 - 30 mm, and the mass ratio is 1:1;

[0093] S2. Feed the pressed plate into the surface treatment workshop and coat a self-skinning material on the surface of the plate at 65 °C, with a skin thickness of 0.1 mm; after skinning, an environmentally friendly high-temperature heat-insulating nano heat-insulating board is obtained. The preparation method of the skinning material used in this example is as follows:

[0094] Mix 80 g of polyether polyol, 40 g of polymer polyol, 0.9 g of catalyst triethylenediamine, 1.5 g of polyurethane foam stabilizer, 5 g of chain extender ethylene glycol, 1 g of short fibers, and 0.5 g of water to obtain Component A;

[0095] Heat the reactor to 60 °C, add 70 g of isocyanate and 17 g of hydroxy silicone oil and stir evenly. Raise the temperature to 80 °C and react for 4 h. Evacuate and distill under reduced pressure for 2 h to remove the unreacted substances. After cooling, a modified isocyanate is obtained;

[0096] Add 80 g of the modified isocyanate to Component A at 35 °C; quickly stir for 10 s to obtain the self-skinning material. The short fibers used in this example are carbon fibers and zirconia fibers with a length of 5 - 30 mm, and the mass ratio is 1:1;

[0097] S3. Cut the obtained environmentally friendly high-temperature heat-insulating nano heat-insulating board into specified sizes; after encapsulating the nano boards of specified sizes with a polymer film material, the final product is obtained.

[0098] Example 4

[0099] The difference between Example 4 and Example 1 is that the modified nano-silica aerogel used in Example 4 is from Preparation Example 2.

[0100] Example 5

[0101] The difference between Example 5 and Example 1 is that the modified nano-silica aerogel used in Example 5 is from Preparation Example 3.

[0102] Example 6

[0103] The difference between Example 6 and Example 1 is that the modified nano-silica aerogel used in Example 6 is from Preparation Example 4.

[0104] Example 7

[0105] Example 7 is different from Example 1 in that the modified nano-silica aerogel used in Example 7 is from Preparation Example 5.

[0106] Example 8

[0107] Example 8 is different from Example 1 in that the modified nano-silica aerogel used in Example 8 is from Preparation Example 6.

[0108] Example 9

[0109] Example 9 is different from Example 1 in that the modified nano-silica aerogel used in Example 9 is from Preparation Example 7.

[0110] Comparative Example 1

[0111] Comparative Example 1 is different from Example 1 in that an equal amount of nano-silica powder is used in Comparative Example 1 to replace the hydroxy silicone oil modified macroporous nano-silica aerogel.

[0112] Comparative Example 2

[0113] Comparative Example 2 is different from Example 1 in that the hydroxy silicone oil modified macroporous nano-silica aerogel is not modified with a tackifier and a coupling agent in Comparative Example 2.

[0114] Comparative Example 3

[0115] Comparative Example 3 is different from Example 1 in that an equal amount of nano-silica powder is directly used in Comparative Example 3 to replace the modified nano-silica aerogel.

[0116] Performance detection test

[0117] I. Referring to GB / T 3001-2017 "Test Method for Cold Bending Strength of Refractory Materials", the flexural strength of the nano-insulation boards obtained in Examples 1-9 and Comparative Examples 1-3 was detected, and the results are shown in Table 1.

[0118] II. Referring to the method in YB-T4130-2005 "Test Method for Thermal Conductivity of Refractory Materials (Water Flow Flat Plate Method)", the thermal conductivity of the nano-insulation boards obtained in Examples 1-9 and Comparative Examples 1-3 at 1000 °C was tested, and the results are shown in Table 1.

[0119] The specific detection results are as follows:

[0120] Table 1 Performance detection results

[0121] Flexural strength / MPa Thermal conductivity at 1000℃ / [W / (m·K)] Example 1 0.56 0.086 Example 2 0.65 0.065 Example 3 0.61 0.074 Example 4 0.62 0.079 Example 5 0.57 0.081 Example 6 0.58 0.082 Example 7 0.54 0.088 Example 8 0.59 0.085 Example 9 0.55 0.086 Comparative Example 1 0.45 0.16 Comparative Example 2 0.42 0.11 Comparative Example 3 0.38 0.22

[0122] As can be seen from the test results in Table 1, the flexural strength of the nano thermal insulation board provided by this application is not less than 0.5 MPa, and the thermal conductivity at 1000 °C reaches 0.065 W / (m·K), indicating that the nano thermal insulation board provided by this application has excellent thermal insulation performance and flexural resistance.

[0123] This specific embodiment is only an interpretation of this application and does not limit this application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of this application, it is protected by the patent law.

Claims

1. A preparation method of an environmentally friendly and high-temperature heat-insulating nano heat-insulating board, characterized in that: It includes the following steps: S1. Stir the modified nano-silica aerogel, light-shielding agent, and short fibers evenly to obtain a mixture. Feed the mixture into the mold of a press and press it into a plate at 100 - 120 °C and 4.41 - 15.68 MPa. After the plate comes out of the mold, suck off the excess dust. S2. Feed the pressed plate into the surface treatment workshop and coat a self-skinning material on the surface of the plate. After skinning, an environmentally friendly high-temperature heat-insulating nano heat-insulating board is obtained. S3. Cut the obtained environmentally friendly high-temperature heat-insulating nano heat-insulating board into specified sizes; after encapsulating the nano boards of specified sizes with a polymer film material, the final product is obtained. The mass ratio of the modified nano-silica aerogel, light-shielding agent, and short fibers is 40 - 60:10 - 30:2 - 4. The raw materials of the modified nano-silica aerogel include 99 - 99.5% of hydroxy silicone oil-modified macroporous nano-silica aerogel, 0.2 - 0.3% of tackifying modifier, and 0.3 - 0.7% of coupling agent by mass percentage.

2. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1, characterized in that: The hydroxy silicone oil-modified macroporous nano-silica aerogel is prepared from the following raw materials in parts by weight: 17 - 21 parts of sodium silicate, 900 - 1000 parts of water, 100 - 120 parts of water glass, 45 - 65 parts of dilute sulfuric acid, 0.005 - 0.007 parts of cetyltrimethylammonium bromide, and 5 - 15 parts of hydroxy silicone oil.

3. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 2, characterized in that: The preparation method of the hydroxy silicone oil-modified macroporous nano-silica aerogel includes the following steps: S1. Add sodium silicate to water, stir at a constant temperature of 80 - 90 °C, and simultaneously drop in water glass and dilute sulfuric acid. After dropping, adjust the pH to 7 and when gelation occurs, then add cetyltrimethylammonium bromide and hydroxy silicone oil in sequence, keep warm for 2 - 4 h, and then adjust the pH to 3 - 4 to end the reaction to obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake. S2. Dilute the above nano-silica filter cake with water, place it on a high-speed shear emulsifier, emulsify the nano-silica filter cake at 1500 - 2000 rpm for 15 - 20 min, and dry the emulsified slurry with an experimental spray dryer under the drying parameters of an air extraction frequency of 30 - 32 Hz, a feeding speed of 15 - 17 rpm, an atomization pressure of 0.3 - 0.5 MPa, an inlet temperature of 200 - 220 °C, and an outlet temperature of 105 - 115 °C to obtain nano-silica powder and pulverize it, thus obtaining the hydroxy silicone oil-modified macroporous nano-silica aerogel.

4. The preparation method of an environment-friendly high-temperature heat-insulating nano heat-insulating board according to claim 1 or 2 or 3, characterized in that: The pore volume of the hydroxyl silicone oil modified mesoporous silica aerogel with large pore volume is 1.5 - 3 cm 3 / g.

5. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1, characterized in that: The tackifying modifier includes C5 resin, C9 resin, and phosphosilicate; the mass ratio of C5 resin, C9 resin, and phosphosilicate is 1:0.8 - 1:0.9 - 1.

1.

6. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1, characterized in that: The preparation method of the modified nano-silica aerogel includes the following steps: Mix the coupling agent and the tackifying modifier, and then add the hydroxy silicone oil-modified macroporous nano-silica aerogel, and mix at a temperature of 120 - 160 °C and a rotation speed of 800 - 1000 rpm to obtain the modified nano-silica aerogel.

7. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1, characterized in that: The self-skinning material includes component A and component B; the raw materials of component A include 60-80 parts by weight of polyether polyol, 20-40 parts by weight of polymer polyol, 0.3-0.9 parts by weight of catalyst, 0.5-1.5 parts by weight of foam stabilizer, 2-5 parts by weight of chain extender, 0.1-1 part by weight of short fiber, and 0.1-0.5 part by weight of water; component B is a modified isocyanate.

8. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1, characterized in that: The preparation method of the modified isocyanate includes the following steps: Heat the reactor to 40-60 °C, add 60-70 parts by weight of isocyanate and 15-17 parts by weight of hydroxyl silicone oil, stir evenly, heat up to 70-80 °C and react for 2-4 h, evacuate, and carry out vacuum distillation for 1-2 h to remove unreacted substances. After cooling, the modified isocyanate is obtained.

9. The preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to claim 1 or 7, characterized in that: The short fiber is one or a mixture of more than one of glass fiber, alumina fiber, carbon fiber, and zirconia fiber; the length of the short fiber is 5-30 mm.

10. An environmentally friendly high-temperature heat-insulating nano heat-insulating board prepared by the preparation method of an environmentally friendly high-temperature heat-insulating nano heat-insulating board according to any one of claims 1-9.