阅读说明：本技术 一种纳米复合隔热板及其制备方法 (Nano composite heat insulation plate and preparation method thereof ) 是由 张成贺 任大贵 刘超 岳耀辉 刘焕英 于 2019-10-21 设计创作，主要内容包括：本发明提供了一种纳米复合隔热板,由以下原料制备得到；所述原料包括：30～40重量份粒径为20～30nm的二氧化硅；30～40重量份粒径为400～600nm的二氧化硅；5～10重量份的膨胀珍珠岩；5～10重量份的红外遮光剂；2～5重量份的无机耐火纤维；5～8重量份的无机胶黏剂。与现有技术相比,本发明通过引入粒径为400～600nm的二氧化硅和膨胀珍珠岩,使纳米复合隔热板具有更好地颗粒配级,从而使内部孔洞直径分布更加均匀,有效降低对流传热,同时引入无机胶黏剂,可保证纳米复合隔热板的常温和烧后强度,其为纯无机制品,高温下无烟无味,且成本较低。(The invention provides a nano composite heat insulation plate which is prepared from the following raw materials; the raw materials comprise: 30-40 parts by weight of silica having a particle diameter of 20-30 nm; 30 to 40 parts by weight of silica having a particle diameter of 400 to 600 nm; 5-10 parts by weight of expanded perlite; 5-10 parts by weight of an infrared opacifier; 2-5 parts by weight of inorganic refractory fiber; 5-8 parts of inorganic adhesive. Compared with the prior art, the nano composite heat insulation board has the advantages that the silica and the expanded perlite with the particle size of 400-600 nm are introduced, so that the nano composite heat insulation board has better particle grading, the diameter distribution of the inner holes is more uniform, the convection heat transfer is effectively reduced, meanwhile, the inorganic adhesive is introduced, the normal temperature and the strength after firing of the nano composite heat insulation board can be ensured, the nano composite heat insulation board is a pure inorganic product, and the nano composite heat insulation board is smokeless and odorless at high temperature and has lower cost.)

1. The nano composite heat insulation plate is characterized by being prepared from the following raw materials; the raw materials comprise: 30-40 parts by weight of silica having a particle diameter of 20-30 nm; 30 to 40 parts by weight of silica having a particle diameter of 400 to 600 nm; 5-10 parts by weight of expanded perlite; 5-10 parts by weight of an infrared opacifier; 2-5 parts by weight of inorganic refractory fiber; 5-8 parts of inorganic adhesive.

2. The nanocomposite thermal insulation panel according to claim 1, wherein the bulk density of the expanded perlite is 60 to 80kg/m³。

3. The nanocomposite insulation panel of claim 1, wherein the infrared opacifier is selected from one or more of silicon carbide, carbon black, zirconium silicate and titanium dioxide.

4. The nanocomposite insulation panel of claim 1, wherein the infrared opacifier has a particle size of 3 to 5 μm.

5. The nanocomposite insulation panel of claim 1, wherein the inorganic nanofibers are selected from one or more of glass fibers, high silica fibers, and ceramic fibers.

6. The nanocomposite insulation panel of claim 5, wherein the fiber diameters of the glass fibers and the high silica fibers are each independently 7 to 9 μm; the fiber diameter of the ceramic fiber is 3-5 μm.

7. The nanocomposite insulation panel according to claim 1, wherein the inorganic binder is selected from silica sol or water glass.

8. The nanocomposite thermal insulation board according to claim 7, wherein the concentration of the silica sol is 30 to 40 wt%; the concentration of the water glass is 20-30 wt%.

9. A method for preparing a nanocomposite thermal insulation board according to any one of claims 1 to 8, comprising:

s1) mixing and stirring silicon dioxide with the particle size of 20-30 nm, silicon dioxide with the particle size of 400-600 nm, expanded perlite, an infrared opacifier and inorganic refractory fibers to obtain a mixture;

s2) spraying inorganic adhesive into the mixture, continuing stirring after spraying, and performing compression molding to obtain the nano composite heat insulation board.

10. The method according to claim 9, wherein the stirring speed in the step S1) is 400 to 600 rpm; stirring for 10-15 min; the stirring speed in the step S2) is 300-400 rpm; the continuous stirring time is 3-5 min; the pressure of the compression molding is 300-500 MPa; and the pressure maintaining time is 60-90 s during the compression molding.

Technical Field

The invention belongs to the technical field of heat insulation materials, and particularly relates to a nano composite heat insulation plate and a preparation method thereof.

Background

With the gradual increase of national environmental protection treatment and energy conservation and emission reduction, light heat insulation materials with better energy-saving effect and more environmental protection are sought in the industries such as petrifaction, metallurgy, ceramic kiln furnaces and glass kiln furnaces. The traditional light heat insulating material at present comprises ceramic fiber products and calcium silicate products, and in order to ensure the strength of the products, part of organic bonding agents are usually introduced in the production process. The existence of organic components causes a large amount of smoke generated in the using process and causes pollution to the environment. The average thermal conductivity of the two light heat insulating materials at 500 ℃ is about 0.12W/(m.K), and compared with a nanometer material, the heat insulating material has higher thermal conductivity and poor heat insulating property. At present, the mature nano material in the market is a nano microporous thermal insulation board, the silicon dioxide material with the average particle size of 20-30 nm accounts for more than 80%, the average thermal conductivity at 500 ℃ is 0.03W/(m.K), the thermal conductivity is low, and the thermal insulation performance is excellent. However, the material is limited by the cost of raw materials, the price is generally high, and the industrial application is hindered. The market needs more cost-effective products.

Chinese patent with publication number CN104086116A discloses a nano-microporous heat-insulating plate, which is prepared from 20-35% of kaolin, 50-65% of white carbon black and nano-SiO₂Powder, 5-15% of polypropylene fiber, 3-5% of refractory fiber cotton and 5-10% of binder, white carbon black and nano SiO₂The weight ratio of the powder is 1: 1; the preparation process comprises grinding, mixing, isostatic pressing to obtain semi-finished product, oven drying, cutting, and packaging to obtain the final product, wherein the shrinkage of the heating wire at 800 deg.C is less than or equal to 1.9%, and the shrinkage of the heating wire is small and uniform; in addition, the paint is not easy to oxidize and drop slag in the using process, and has good thermal stability; the nano-microporous structure in the heat insulation plate prolongs the heat conduction path, can obtain lower solid conductivity, can provide the heat insulation performance of a product, and has the heat conductivity of only one third of that of ceramic fibers. However, the nano-microporous heat-insulating plate comprises polypropylene fibers, the polypropylene fibers can melt and volatilize under high temperature environment, and the nano-pores collapse in the melting and volatilizing process, so that the heat conduction is causedAn increase in thermal coefficient; meanwhile, pungent smell and smoke can be generated at high temperature, and the environment and the human health are harmed.

Chinese patent with publication number CN108298995A discloses a low-dimensional SiO₂The high-strength light heat-insulating material is prepared by using silicon dioxide micropowder with the granularity of 300-500 nm and silicon dioxide with the granularity of 100-200 nm as main raw materials, and CaO-MgO-SiO₂Obtaining low-dimensional SiO by using refractory fiber as reinforcing material₂The light heat insulating material is prepared through spraying superfine inorganic fiber glue on the surface of the material and low temperature sintering. The light heat-insulating material takes the byproduct silicon dioxide micro powder as a main raw material, takes biomass soluble fiber harmless to human bodies as a reinforcing material, and arranges the spray glue on the surface of a green brick to improve the strength of the green brick, reduce the molding pressure, increase the internal porosity of the green brick and reduce the heat conductivity of the heat-insulating material; the low-temperature sintering improves the strength of the product, does not change the microporous structure of the heat-insulating material, does not increase the heat conductivity during high-temperature work, prevents the occurrence of moisture absorption and hydration of the heat-insulating brick, and further increases the heat-insulating property. However, the heat insulation material needs to be calcined at 800-900 ℃ for 0.5-1 h, the energy consumption is large, the production cost is high, the selected base material is a micron material actually, and holes formed by stacking are large.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a nanocomposite thermal insulation board with uniform pore diameter distribution, low thermal conductivity and high strength, and a method for manufacturing the same.

The invention provides a nano composite heat insulation plate which is prepared from the following raw materials; the raw materials comprise: 30-40 parts by weight of silica having a particle diameter of 20-30 nm; 30 to 40 parts by weight of silica having a particle diameter of 400 to 600 nm; 5-10 parts by weight of expanded perlite; 5-10 parts by weight of an infrared opacifier; 2-5 parts by weight of inorganic refractory fiber; 5-8 parts of inorganic adhesive.

Preferably, the bulk density of the expanded perlite is 60-80 kg/m³。

Preferably, the infrared opacifier is selected from one or more of silicon carbide, carbon black, zirconium silicate and titanium dioxide.

Preferably, the particle size of the infrared opacifier is 3-5 μm.

Preferably, the inorganic nanofibers are selected from one or more of glass fibers, high silica fibers and ceramic fibers.

Preferably, the fiber diameters of the glass fiber and the high silica fiber are respectively and independently 7-9 μm; the fiber diameter of the ceramic fiber is 3-5 μm.

Preferably, the inorganic adhesive is selected from silica sol or water glass.

Preferably, the concentration of the silica sol is 30-40 wt%; the concentration of the water glass is 20-30 wt%.

The invention also provides a preparation method of the nano composite heat insulation plate, which comprises the following steps:

s1) mixing and stirring silicon dioxide with the particle size of 20-30 nm, silicon dioxide with the particle size of 400-600 nm, expanded perlite, an infrared opacifier and inorganic refractory fibers to obtain a mixture;

s2) spraying inorganic adhesive into the mixture, continuing stirring after spraying, and performing compression molding to obtain the nano composite heat insulation board.

Preferably, the stirring speed in the step S1) is 400-600 rpm; stirring for 10-15 min; the stirring speed in the step S2) is 300-400 rpm; the continuous stirring time is 3-5 min; the pressure of the compression molding is 300-500 MPa; and the pressure maintaining time is 60-90 s during the compression molding.

The invention provides a nano composite heat insulation plate which is prepared from the following raw materials; the raw materials comprise: 30-40 parts by weight of silica having a particle diameter of 20-30 nm; 30 to 40 parts by weight of silica having a particle diameter of 400 to 600 nm; 5-10 parts by weight of expanded perlite; 5-10 parts by weight of an infrared opacifier; 2-5 parts by weight of inorganic refractory fiber; 5-8 parts of inorganic adhesive. Compared with the prior art, the nano composite heat insulation board has the advantages that the silica and the expanded perlite with the particle size of 400-600 nm are introduced, so that the nano composite heat insulation board has better particle grading, the diameter distribution of the inner holes is more uniform, the convection heat transfer is effectively reduced, meanwhile, the inorganic adhesive is introduced, the normal temperature and the strength after firing of the nano composite heat insulation board can be ensured, the nano composite heat insulation board is a pure inorganic product, and the nano composite heat insulation board is smokeless and odorless at high temperature and has lower cost.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a nano composite heat insulation plate which is prepared from the following raw materials; the raw materials comprise: 30-40 parts by weight of silica having a particle diameter of 20-30 nm; 30 to 40 parts by weight of silica having a particle diameter of 400 to 600 nm; 5-10 parts by weight of expanded perlite; 5-10 parts by weight of an infrared opacifier; 2-5 parts by weight of inorganic refractory fiber; 5-8 parts of inorganic adhesive.

In some embodiments provided by the invention, the content of the silica with the particle size of 20-30 nm is preferably 30 parts by weight; in some embodiments provided by the invention, the content of the silica with the particle size of 20-30 nm is preferably 35 parts by weight; in other embodiments provided by the present invention, the content of the silica having a particle size of 20 to 30nm is preferably 40 parts by weight.

In some embodiments provided by the present invention, the content of the silica having a particle size of 400 to 600nm is preferably 40 parts by weight; in other embodiments provided by the present invention, the content of the silica having a particle size of 400 to 600nm is preferably 30 parts by weight.

The mass ratio of the silicon dioxide with the particle size of 20-30 nm to the silicon dioxide with the particle size of 400-600 nm is preferably (3-4): (4-3).

The nano composite heat insulation board provided by the invention is added with expanded perlite, and silicon dioxide with the particle size of 400-600 nm and the expanded perlite are introducedThe nanometer composite heat insulation board has better particle grading, thereby the diameter distribution of the inner holes is more uniform, and the convection heat transfer is effectively reduced. The mass ratio of the silicon dioxide with the particle size of 400-600 nm to the expanded perlite is (3-8) in a vortex: 1; the preferred bulk density of the expanded perlite is 60-80 kg/m³(ii) a In some embodiments provided herein, the expanded perlite is preferably present in an amount of 10 parts by weight; in other embodiments provided herein, the expanded perlite is preferably present in an amount of 5 parts by weight.

According to the invention, the content of the infrared opacifier is preferably 8-10 parts by weight; the infrared opacifier is preferably one or more of silicon carbide, carbon black, zirconium silicate and titanium dioxide; the particle size of the infrared opacifier is preferably 3-5 microns; in some embodiments provided herein, the infrared opacifier is preferably present at 8 parts by weight; in other embodiments provided herein, the infrared opacifier is preferably present at 10 parts by weight. The infrared opacifier is added into the nano composite heat insulation board provided by the invention, so that the radiation heat transfer coefficient at high temperature is further reduced, and the heat insulation performance is improved.

The inorganic refractory fiber is preferably one or more of glass fiber, high silica fiber and ceramic fiber; the diameters of the glass fibers and the high silica fibers are respectively and independently preferably 7-9 mu m; the fiber diameter of the ceramic fiber is preferably 3-5 μm; the average length of the inorganic refractory fibers is preferably 5-15 mm; in some embodiments provided herein, the inorganic refractory fibers are preferably present in an amount of 2 parts by weight; in other embodiments provided herein, the inorganic refractory fibers are preferably present in an amount of 5 parts by weight.

The inorganic adhesive is preferably silica sol or water glass; the concentration of the silica sol is preferably 30-40 wt%; the concentration of the water glass is preferably 20-30 wt%, and more preferably 30 wt%; in some embodiments provided herein, the content of the inorganic adhesive is preferably 8 parts by weight; in some embodiments provided herein, the content of the inorganic adhesive is preferably 5 parts by weight; in other embodiments provided by the present invention, the content of the inorganic adhesive is preferably 7 parts by weight.

According to the invention, the silica and the expanded perlite with the particle size of 400-600 nm are introduced, so that the nano composite heat insulation board has better particle grading, the diameter distribution of the inner holes is more uniform, the convection heat transfer is effectively reduced, and meanwhile, the inorganic adhesive is introduced, so that the normal temperature and the strength after firing of the nano composite heat insulation board can be ensured, and the nano composite heat insulation board is a pure inorganic product, is smokeless and odorless at high temperature and has lower cost.

The invention also provides a preparation method of the nano composite heat insulation plate, which comprises the following steps: s1) mixing and stirring silicon dioxide with the particle size of 20-30 nm, silicon dioxide with the particle size of 400-600 nm, expanded perlite, an infrared opacifier and inorganic refractory fibers to obtain a mixture; s2) spraying inorganic adhesive into the mixture, continuing stirring after spraying, and performing compression molding to obtain the nano composite heat insulation board.

In the present invention, the sources of all raw materials are not particularly limited, and they may be commercially available.

Mixing and stirring silicon dioxide with the particle size of 20-30 nm, silicon dioxide with the particle size of 400-600 nm, expanded perlite, an infrared opacifier and inorganic refractory fibers to obtain a mixture; the silicon dioxide, the expanded perlite, the infrared opacifier and the inorganic refractory fiber are the same as those described above, and are not described again; the mixing and stirring speed is preferably 400-600 rpm; the mixing and stirring time is preferably 10-15 min.

Spraying an inorganic adhesive into the mixture; the inorganic adhesive is the same as described above, and is not described herein again.

After spraying is finished, stirring is continued; the rotation speed of the continuous stirring is preferably 300-400 rpm; the continuous stirring time is preferably 3-5 min.

After stirring, pressing and forming to obtain the nano composite heat insulation plate; the press forming is preferably carried out by adopting a hydraulic press; the pressure for press forming is preferably 300-500 MPa; the pressure maintaining time of the compression molding is preferably 60-90 s.

In order to further illustrate the present invention, the following describes a nanocomposite thermal insulation board and a method for manufacturing the same in detail with reference to the following examples.

The reagents used in the following examples are all commercially available; for the purpose of comparison, the sample sizes prepared in the following examples and comparative examples are 300X 20 mm.