[0021] The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.
[0022] Such as figure 1 Shown is a flowchart of an embodiment of a method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0023] Step 101: Mix 60-100% by weight of nano-silica powder, 0-35% by weight of reinforcing fibers and 0-30% by weight of infrared sunscreen and put them into a closed mixer. ;
[0024] Among them, the weight percentage of the nano-silica powder put into the closed mixer is 70-98%, the weight percentage of the reinforcing fiber is 2-25%, and the weight percentage of the infrared sunscreen is 0 -25%; the above-mentioned silica powder can be flame silica fume, fumed silica, biological silica, silica aerogel powder, hollow fiber silica prepared by asbestos acid etching, etc., and it can be Commercially available products, such as Aerosi1812 from Degussa, have a particle size of 7-14 nanometers; and HL-150 from Guangzhou Jibisheng Technology Industrial Co., Ltd., have a particle size of 7-40 nanometers. The above-mentioned reinforcing fibers can be ultrafine glass fibers, glass fibers, aluminum silicate fibers, alumina fibers, mullite fibers, xonotlite fibers, zirconia fibers, high silica fibers, rock wool fibers, mineral wool fibers, One or any combination of basalt fiber, aramid fiber, textile fiber, brucite fiber, asbestos fiber, sepiolite fiber, attapulgite fiber, wollastonite fiber, etc.; and the aforementioned brucite, sepiolite Natural mineral fibers such as asbestos, attapulgite, wollastonite, etc. are pre-superfine dispersion treatment. The pre-superfine dispersion treatment process is as follows: use penetrant (OT) 15 as a dispersant for stirring, ultrasonic vibration, ball milling, etc. After the dispersion method is superfinely dispersed, it is prepared by adding a hydrophobic agent treatment and then drying; wherein, the weight percentage of OT is 0.2-15%, and the hydrophobic agent can be a silicone type hydrophobic agent, specifically, silicone or methyl silyl Sodium silanol, etc., in which the amount of hydrophobic agent added is 0.2-8%; the diameter of the ultra-fine dispersed fibers is mostly nanometers, and the thickest is no more than 200 microns. In addition, the length of the various fibers in the above-mentioned reinforcing fibers is less than or equal to 20 mm, and the fiber diameter is 2 nanometers to 300 microns. The above-mentioned light-shielding agent may be one or any combination of ultrafine powders of titanium dioxide, chromium trioxide, iron trioxide, zirconium oxide, silicon carbide, silicon nitride and the like. The particle size of the above-mentioned ultrafine powder is less than 250 nanometers, for example Ti-pure, R-103, etc. produced by dupont can be used;
[0025] Step 102: Use dry high-speed stirring to uniformly disperse the mixture in the enclosed stirrer to make an indefinite heat-insulating material, or make a molded product heat-insulating material through a molding method.
[0026] Among them, the dry method is used for high-speed stirring for 2-30 minutes to disperse the mixture in the closed stirrer evenly, and place it in a mold for compression to form a molded product thermal insulation material. The shape of the molded product thermal insulation material can be a block , Plate, shell and tube, etc.; the shape of the unshaped insulation material is usually powder.
[0027] The preparation method of the above-mentioned nano-silica heat-insulating material is to mix a certain proportion of nano-silica powder, reinforcing fibers and infrared shading agent uniformly, and the prepared amorphous or formed heat-insulating material has excellent heat insulation performance, and the preparation process is simple, Easy to operate, low preparation cost, and wide application range; at the same time, since there are no organic ingredients in the preparation materials and the preparation process is completed in a closed mixer, each component has less volatilization and is environmentally friendly.
[0028] Such as figure 2 Shown is a flow chart of Embodiment 1 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0029] Step 201, mixing the nano-silica powder, the brucite fiber, and the carbonized silicon powder at a ratio of 60:25:15 by weight to form a mixture;
[0030] Among them, the brucite fiber is a fiber whose length is not longer than 8mm after ultrafine dispersion treatment;
[0031] Step 202: Add the above-mentioned mixture to a closed agitator, stir and disperse at high speed for 30 minutes, put it into an abrasive tool, and then press and shape it to obtain a product of a specified shape.
[0032] Such as image 3 Shown is a flowchart of Embodiment 2 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0033] Step 301: Mix the nano-silica powder, aluminum silicate fiber and carbonized silicon powder at a ratio of 85:5:10 by weight to form a mixture;
[0034] Among them, the length of the aluminum silicate fiber is 5mm;
[0035] Step 302: Add the above mixture to a closed mixer, stir and disperse at high speed for 15 minutes, put it into a packaging bag, and package it for later use.
[0036] Such as Figure 4 Shown is a flow chart of Embodiment 3 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0037] Step 401, mixing the nano-silica powder: glass fiber: carbonized silicon powder at a ratio of 95:3:2 by weight to form a mixture;
[0038] Among them, the length of the glass fiber is 8mm;
[0039] Step 402: Add the above mixture to a closed mixer and stir and disperse at high speed for 15 minutes. After the mixture is uniformly stirred and dispersed, it is put into an abrasive tool and then pressurized to form a product with a specified shape.
[0040] Hydrophobic type used at high temperature,
[0041] Such as Figure 5 Shown is a flowchart of Embodiment 4 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0042] Step 501, the nano fumed silica powder, glass fiber, titanium dioxide (TiO 2 ) The powder is mixed uniformly in a ratio of 80:8:12 by weight to form a mixture;
[0043] Among them, the length of the glass fiber is 6mm;
[0044] Step 502: Add the above mixture to a closed mixer and stir and disperse at a high speed for 15 minutes. After the mixture is uniformly stirred and dispersed, it is put into an abrasive tool and then molded under pressure to obtain a product of a specified shape.
[0045] Such as Image 6 Shown is a flowchart of Embodiment 5 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0046] Step 601: Combine flame silica fume powder, aluminum silicate fiber and TiO 2 The powder is evenly mixed in a ratio of 70:7:23 by weight to form a mixture;
[0047] Among them, the length of the aluminum silicate fiber is 8mm;
[0048] Step 602: Add the above mixture to a closed mixer and stir and disperse at high speed for 20 minutes, stir and disperse evenly, put it into an abrasive tool, and then press to form a product with a specified shape.
[0049] Such as Figure 7 Shown is a flowchart of Embodiment 6 of the method for preparing nano-silica thermal insulation material of the present invention, and the method includes:
[0050] Step 701: Combine nano fumed silica powder, glass fiber and TiO 2 The powder is uniformly mixed in a ratio of 75:15:20 by weight to form a mixture;
[0051] Among them, the length of fiber glass is 6mm;
[0052] Step 702: Add the above mixture to a closed mixer and mix and disperse at high speed for 25 minutes. After the mixture is uniformly stirred and dispersed, it is put into an abrasive tool and then molded under pressure to obtain a product of a specified shape.
[0053] The preparation method of the above-mentioned nano-silica thermal insulation material in Examples 1 to 6, adjusts the formula according to different use environments to prepare different grade series products, and has simple preparation process, easy operation, low preparation cost, wide application range and good environmental friendliness.
[0054] The nano-silica thermal insulation material prepared by the above-mentioned preparation method of the present invention includes: nano-silica powder with a weight percentage of 60-100%; reinforcing fibers with a weight percentage of 0-35%; and infrared sunscreen agent with a weight percentage of 0 -30%.
[0055] Wherein, the weight percentage of the above-mentioned nano silica powder is 70-98%, the weight percentage of the reinforcing fiber is 2-25%, and the weight percentage of the infrared sunscreen is 0-25%.
