An inorganic thermal insulation intermediate coating and its preparation method

Abstract

This invention relates to the technical field of mica functional fillers, and more particularly to an inorganic thermal insulation intermediate coating and its preparation method, comprising the following components: by weight, 20-25 parts inorganic resin, 10-15 parts aerogel, 10-13 parts modified hollow glass microspheres, 1-3 parts mica functional filler, 5-10 parts emulsion, 0.5-0.8 parts dispersant, 0.1-0.2 parts defoamer, and 20-30 parts water, wherein the modified hollow glass microspheres are γ-butylselenolactone-modified hollow glass microspheres; and the mica functional filler is a ternary composite mica filler of boron, zinc, and phosphorus. The inorganic thermal insulation intermediate coating of this invention achieves excellent thermal insulation and flame retardant properties through the rational proportioning and synergistic effect of its components.

Description

Technical Field

[0001] This invention relates to the technical field of mica functional fillers, and more particularly to an inorganic thermal insulation intermediate coating and its preparation method. Background Technology

[0002] Inorganic thermal insulation materials are widely used in building insulation due to their excellent properties such as non-combustibility, high temperature resistance, and non-corrosiveness. Inorganic thermal insulation materials mainly include two categories: fiber insulation materials and foam insulation materials. Commonly used materials include mineral wool, expanded perlite, vermiculite, cenospheres, hollow glass microspheres, and aerogel. Among them, mineral wool is inexpensive but suffers from water absorption, affecting its insulation performance; expanded perlite has a low thermal conductivity but high water absorption and is prone to cracking; cenospheres have a fire resistance of up to 1610℃, but their relatively high thermal conductivity only meets the national standard level II requirement; hollow glass microspheres have good flowability and dispersibility, but pose a risk of structural damage under extreme high temperatures; aerogel, as a nanoporous material, has a thermal conductivity as low as 0.018 W / (m·K), making it the insulation material with the lowest thermal conductivity currently available, but it suffers from drawbacks such as high price, susceptibility to cracking, and production difficulties.

[0003] Chinese patent CN201510060450.4 discloses an inorganic thermal insulation coating and its preparation method. This coating combines the super-insulating function of aerogel materials with the unique water-resistant and flame-retardant properties of magnesium phosphate cementing materials, exhibiting advantages such as low thermal conductivity, good water resistance, good flame retardancy and fire resistance, and environmental friendliness and energy saving. However, this technical solution still has significant shortcomings: First, the existing coating system uses a single type of thermal insulation filler, relying solely on the nanoporous structure of aerogel for insulation, lacking a multi-level, multi-mechanism synergistic insulation system, resulting in limited insulation performance under complex heat transfer conditions; second, the flame retardancy of this solution mainly comes from the inorganic non-combustible properties of magnesium phosphate cementing materials themselves, and its performance needs further improvement under stringent fire protection requirements. Summary of the Invention

[0004] In view of this, the present invention proposes an inorganic thermal insulation intermediate coating and its preparation method to solve the problem of limited thermal insulation and flame retardant effects of existing inorganic coatings.

[0005] The technical solution of this invention is achieved as follows: This invention provides an inorganic thermal insulation intermediate coating, comprising the following components: by weight, 20-25 parts inorganic resin, 10-15 parts aerogel, 3-5 parts modified hollow glass microspheres, 1-3 parts mica functional filler, 5-10 parts emulsion, 0.5-0.8 parts dispersant, 0.1-0.2 parts defoamer, and 20-30 parts water, wherein the modified hollow glass microspheres are γ-butylselenolactone modified hollow glass microspheres; and the mica functional filler is a ternary composite mica filler of boron, zinc, and phosphorus.

[0006] The inorganic thermal insulation intermediate coating of this invention achieves excellent thermal insulation performance through the rational proportioning and synergistic effect of its components. Specifically, the aerogel, with its three-dimensional nano-network structure and low thermal conductivity, provides superior thermal insulation performance; the modified hollow glass microspheres, modified with γ-butylselenolactone, not only maintain the thermal insulation advantages of the hollow structure but also enhance the interfacial bonding with the matrix, while the introduced selenium element endows the material with antioxidant properties; the mica functional filler, through ternary composite modification with boron, zinc, and phosphorus, constructs a PB-Zn crosslinked network based on the mica sheet structure, possessing a triple flame-retardant mechanism of gas-phase flame retardancy, solid-phase char formation, and catalytic synergy; the inorganic resin, as the main binder, provides good bonding strength and high-temperature resistance; and the addition of emulsion improves the coating's workability and flexibility.

[0007] Based on the above technical solutions, preferably, the preparation method of the modified hollow glass microspheres includes:

[0008] A1. Hollow glass microspheres were dispersed in ethanol and ultrasonically dispersed. γ-glycidoxypropyltrimethoxysilane was added dropwise. The mixture was reacted at 70-90℃ for 4-5 hours under nitrogen protection to obtain epoxidized hollow glass microspheres.

[0009] A2. Epoxidized hollow glass microspheres were dispersed in anhydrous tetrahydrofuran, and γ-butylselenolactone and 4-dimethylaminopyridine were added. The mixture was reacted at 30-40℃ for 0.5-1h under nitrogen protection to obtain modified hollow glass microspheres.

[0010] Specifically, reactive sites are introduced on the surface of hollow glass microspheres through epoxidation modification; then, γ-butylselenolactone is grafted onto the surface of hollow glass microspheres through ring-opening reaction. The introduction of selenium endows the material with antioxidant and UV-resistant properties, significantly improving the aging resistance of the coating.

[0011] Based on the above technical solutions, preferably, in step A1, the mass ratio of hollow glass microspheres to γ-glycidoxypropyltrimethoxysilane is 1:0.03-0.08; in step A2, the mass ratio of epoxidized hollow glass microspheres, γ-butylselenolactone, and 4-dimethylaminopyridine is 100:4-8:0.6-0.8.

[0012] Based on the above technical solutions, preferably, the preparation method of the mica functional filler includes:

[0013] B1. Grind and mix boric acid and zinc oxide, disperse in anhydrous ethanol to obtain a suspension; add pretreated mica powder to the suspension, stir and mix, add concentrated phosphoric acid and melamine, stir for 30 min, dry to obtain a mixture;

[0014] B2. The mixture is calcined at high temperature under nitrogen protection to obtain mica functional filler.

[0015] Specifically, phosphoric acid molecules bind to active sites on the mica surface and simultaneously undergo an acid-base neutralization reaction with melamine to form a precursor structure of ammonium phosphate. Boric acid and zinc oxide are dispersed in the phosphoric acid-melamine reaction system. Through high-temperature calcination, a synergistic flame-retardant system of ammonium polyphosphate and zinc borate is generated on the mica surface. Phosphorus mainly plays a role in catalyzing char formation in the condensed phase, while zinc borate acts as a char layer reinforcing agent, improving the density of the char layer. The three work synergistically to achieve highly efficient flame-retardant function.

[0016] Based on the above technical solutions, preferably, the pretreated mica powder is added to a 1-2 mol / L hydrochloric acid solution, stirred at 40-50℃ for 2-3 hours, filtered and dried to obtain pretreated mica powder.

[0017] Based on the above technical solutions, preferably, in step B2, the mass ratio of pretreated mica powder, boric acid and zinc oxide is 1:0.08-0.12:0.04-0.08, the amount of concentrated phosphoric acid added is 20-25% of the mass of pretreated mica powder, and the amount of melamine added is 15-20% of the mass of pretreated mica powder.

[0018] Based on the above technical solutions, preferably, in step B2, the high-temperature calcination includes: first heating the mixture to 120-180℃ and holding it at that temperature for 1-1.5 hours under nitrogen protection, and finally heating it to 280-300℃ and holding it at that temperature for 2-3 hours.

[0019] Based on the above technical solutions, preferably, the dispersant includes sodium polycarboxylate, the defoamer is an organosilicon defoamer, the inorganic resin is potassium silicate, the emulsion is an acrylic emulsion, and the aerogel is a silica aerogel.

[0020] This invention also provides a method for preparing an inorganic thermal insulation intermediate coating, comprising the following steps:

[0021] S1. Add the aerogel to water and stir to disperse it. Then, while stirring, continue to add the inorganic resin and dispersant and stir for 20-40 minutes to obtain the basic slurry.

[0022] S2. Under stirring, add modified hollow glass microspheres and mica functional filler to the base slurry, disperse at high speed for 10-20 minutes, then add emulsion, stir at low speed for 10-20 minutes, add defoamer, and continue stirring for 5-10 minutes to obtain the coating.

[0023] This invention also provides an application of an inorganic thermal insulation intermediate coating, which is applied in the field of thermal insulation boards.

[0024] The inorganic thermal insulation intermediate coating and its preparation method of the present invention have the following advantages over the prior art:

[0025] This invention utilizes the synergistic combination of modified hollow glass microspheres and mica functional fillers, along with the ultra-low thermal conductivity of aerogel and the excellent bonding properties of inorganic resins, to construct a multi-level thermal insulation barrier system. This significantly improves the thermal insulation performance of the coating. The hollow structure of the modified glass microspheres complements the nanoporous structure of the aerogel, effectively inhibiting the transmission paths of heat conduction, heat convection, and heat radiation. Meanwhile, the introduction of selenium functional groups endows the material with antioxidant and anti-aging properties. The ammonium polyphosphate-zinc borate flame retardant system loaded on the surface of the mica functional filler provides excellent fire safety, achieving an organic unity of thermal insulation, flame retardancy, and durability. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that the acrylic emulsion is Rosef 5566 emulsion, the defoamer is TEGOFoamex 810, and the dispersant is BASF Dispex® AA 4140; the hollow glass microspheres were purchased from Shijiazhuang Chaowei New Material Technology Co., Ltd., model CW003; the mica powder was purchased from Lingshou County Maosheng Mining Co., Ltd., with a particle size of 200 mesh; and the aerogel is nano-silica aerogel, purchased from Shanghai Jiadeer Chemical Technology Co., Ltd.

[0028] Example 1

[0029] This embodiment provides an inorganic thermal insulation intermediate coating and its preparation method. By weight, it comprises 22 parts potassium silicate, 12.5 parts aerogel, 11.5 parts modified hollow glass microspheres, 2 parts mica functional filler, 8 parts acrylic emulsion, 0.6 parts dispersant, 0.15 parts defoamer, and 25 parts water. The preparation method of this coating is as follows:

[0030] The aerogel was slowly added to water and stirred at low speed (300 rpm) for 30 minutes to fully wet and disperse it. While stirring, potassium silicate and dispersant were added, and the stirring speed was adjusted to 500 rpm and stirred for 30 minutes to obtain the base slurry. While stirring, modified hollow glass microspheres and mica functional filler were added to the base slurry in sequence and dispersed at high speed of 1500 rpm for 15 minutes using a high-speed disperser. The stirring speed was reduced to 400 rpm and added slowly. Acrylic emulsion was added slowly and stirred at low speed for 15 minutes. Defoamer was added and stirring was continued for 8 minutes. Impurities were removed by passing through a 120-mesh sieve to obtain the coating.

[0031] The preparation methods for modified hollow glass microspheres include:

[0032] (1) 100g of hollow glass microspheres were dispersed in 1000ml of ethanol and ultrasonically dispersed for 15min. Under nitrogen protection, 5.5g of γ-glycidoxypropyltrimethoxysilane was added dropwise and the temperature was raised to 80℃ for 4.5h. After the reaction was completed, the microspheres were centrifuged (3000rpm, 10min), washed three times with anhydrous ethanol, and vacuum dried to obtain epoxidized hollow glass microspheres.

[0033] (2) 100g of epoxidized hollow glass microspheres were dispersed in 1000ml of anhydrous tetrahydrofuran and ultrasonically dispersed for 15min. Under nitrogen protection, 6g of γ-butylselenolactone and 0.7g of 4-dimethylaminopyridine were added and reacted at 28℃ for 0.8h. After the reaction was completed, the microspheres were separated by centrifugation, dried under vacuum with anhydrous tetrahydrofuran and anhydrous ethanol, ground and sieved to obtain modified hollow glass microspheres.

[0034] Methods for preparing mica functional fillers include:

[0035] (1) Add 100g of mica powder to a 1.5mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stir at 45℃ for 2.5h, filter, wash with deionized water until neutral, and dry to obtain pretreated mica powder; grind 10g of boric acid and 6g of zinc oxide in an agate mortar for 30min, disperse in 1000ml of anhydrous ethanol, and sonicate for 15min to obtain a suspension; add 100g of pretreated mica powder to the suspension, stir mechanically for 30min, add 23g of concentrated phosphoric acid (mass percentage of 85% H3PO4) and 18g of melamine, stir for 30min, and dry to obtain a mixture;

[0036] (2) Place the mixture in a tube furnace, introduce nitrogen (flow rate 200 mL / min), raise the temperature to 150℃ at a rate of 5℃ / min and hold for 1.3 h; continue to raise the temperature to 290℃ at a rate of 3℃ / min and hold for 2.5 h, cool naturally to room temperature, grind and sieve to obtain mica functional filler.

[0037] Example 2

[0038] This embodiment provides an inorganic thermal insulation intermediate coating and its preparation method. By weight, it comprises 20 parts potassium silicate, 10 parts aerogel, 10 parts modified hollow glass microspheres, 1 part mica functional filler, 5 parts acrylic emulsion, 0.5 parts dispersant, 0.1 parts defoamer, and 20 parts water. The preparation method of this coating is as follows:

[0039] The aerogel was slowly added to water and stirred at low speed (300 rpm) for 30 minutes to fully wet and disperse it. While stirring, potassium silicate and dispersant were added, and the stirring speed was adjusted to 500 rpm. The mixture was stirred for 20 minutes to obtain the base slurry. While stirring, modified hollow glass microspheres and mica functional filler were added to the base slurry in sequence. The mixture was dispersed at high speed (1500 rpm) for 10 minutes using a high-speed disperser. The stirring speed was reduced to 400 rpm and the mixture was added slowly. Acrylic emulsion was added slowly and stirred at low speed for 10 minutes. Defoamer was added and stirring was continued for 5 minutes. Impurities were removed by passing the mixture through a 120-mesh sieve to obtain the coating.

[0040] The preparation methods for modified hollow glass microspheres include:

[0041] (1) 100g of hollow glass microspheres were dispersed in 1000ml of ethanol and ultrasonically dispersed for 15min. Under nitrogen protection, 3g of γ-glycidoxypropyltrimethoxysilane was added dropwise and the temperature was raised to 70℃ for 5h. After the reaction was completed, the microspheres were centrifuged (3000rpm, 10min), washed three times with anhydrous ethanol, and vacuum dried to obtain epoxidized hollow glass microspheres.

[0042] (2) 100g of epoxidized hollow glass microspheres were dispersed in 1000ml of anhydrous tetrahydrofuran and ultrasonically dispersed for 15min. Under nitrogen protection, 4g of γ-butylselenolactone and 0.6g of 4-dimethylaminopyridine were added and reacted at 25℃ for 1h. After the reaction was completed, the microspheres were separated by centrifugation, dried under vacuum with anhydrous tetrahydrofuran and anhydrous ethanol, ground and sieved to obtain modified hollow glass microspheres.

[0043] Methods for preparing mica functional fillers include:

[0044] (1) Add 100g of mica powder to a 1-2mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stir at 40℃ for 3h, filter, wash with deionized water until neutral, and dry to obtain pretreated mica powder; grind 8g of boric acid and 4g of zinc oxide in an agate mortar for 30min, disperse in 1000ml of anhydrous ethanol, and sonicate for 15min to obtain a suspension; add 100g of pretreated mica powder to the suspension, mechanically stir for 30min, add 20g of concentrated phosphoric acid (mass percentage of 85% H3PO4) and 15g of melamine, stir for 30min, and dry to obtain a mixture;

[0045] (2) Place the mixture in a tube furnace, introduce nitrogen (flow rate 200 mL / min), raise the temperature to 120℃ at a rate of 5℃ / min and hold for 1.5 h; continue to raise the temperature to 280℃ at a rate of 3℃ / min and hold for 3 h, cool naturally to room temperature, grind and sieve to obtain mica functional filler.

[0046] Example 3

[0047] This embodiment provides an inorganic thermal insulation intermediate coating and its preparation method. By weight, it comprises 25 parts potassium silicate, 15 parts aerogel, 13 parts modified hollow glass microspheres, 3 parts mica functional filler, 10 parts acrylic emulsion, 0.8 parts dispersant, 0.2 parts defoamer, and 30 parts water. The preparation method of this coating is as follows:

[0048] The aerogel was slowly added to water and stirred at low speed (300 rpm) for 30 minutes to fully wet and disperse it. While stirring, potassium silicate and dispersant were added, and the stirring speed was adjusted to 500 rpm and stirred for 40 minutes to obtain the base slurry. While stirring, modified hollow glass microspheres and mica functional filler were added to the base slurry in sequence and dispersed at high speed of 1500 rpm for 20 minutes using a high-speed disperser. The stirring speed was reduced to 400 rpm and added slowly. Acrylic emulsion was added slowly and stirred at low speed for 20 minutes. Defoamer was added and stirring was continued for 10 minutes. Impurities were removed by passing through a 120-mesh sieve to obtain the coating.

[0049] The preparation methods for modified hollow glass microspheres include:

[0050] (1) 100g of hollow glass microspheres were dispersed in 1000ml of ethanol and ultrasonically dispersed for 15min. Under nitrogen protection, 8g of γ-glycidoxypropyltrimethoxysilane was added dropwise and the temperature was raised to 90℃ for 4h. After the reaction was completed, the microspheres were centrifuged (3000rpm, 10min), washed three times with anhydrous ethanol, and vacuum dried to obtain epoxidized hollow glass microspheres.

[0051] (2) 100g of epoxidized hollow glass microspheres were dispersed in 1000ml of anhydrous tetrahydrofuran and ultrasonically dispersed for 15min. Under nitrogen protection, 8g of γ-butylselenolactone and 0.8g of 4-dimethylaminopyridine were added and reacted at 30℃ for 0.5h. After the reaction was completed, the microspheres were separated by centrifugation, dried under vacuum with anhydrous tetrahydrofuran and anhydrous ethanol, ground and sieved to obtain modified hollow glass microspheres.

[0052] Methods for preparing mica functional fillers include:

[0053] (1) Add 100g of mica powder to a 2mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stir at 50℃ for 2h, filter, wash with deionized water until neutral, and dry to obtain pretreated mica powder; grind 12g of boric acid and 8g of zinc oxide in an agate mortar for 30min, disperse in 1000ml of anhydrous ethanol, and sonicate for 15min to obtain a suspension; add 100g of pretreated mica powder to the suspension, stir mechanically for 30min, add 25g of concentrated phosphoric acid (mass percentage of 85% H3PO4) and 20g of melamine, stir for 30min, and dry to obtain a mixture;

[0054] (2) Place the mixture in a tube furnace, introduce nitrogen (flow rate 200 mL / min), raise the temperature to 180°C at a rate of 5°C / min and hold for 1 h; continue to raise the temperature to 300°C at a rate of 3°C / min and hold for 2 h, cool naturally to room temperature, grind and sieve to obtain mica functional filler.

[0055] Comparative Example 1

[0056] This comparative example provides an inorganic thermal insulation intermediate coating and its preparation method. By weight, it comprises 22 parts potassium silicate, 12.5 parts aerogel, 11.5 parts hollow glass microspheres, 2 parts mica powder, 8 parts acrylic emulsion, 0.6 parts dispersant, 0.15 parts defoamer, and 25 parts water. The preparation method of this coating is as follows:

[0057] The aerogel was slowly added to water and stirred at low speed (300 rpm) for 30 minutes to fully wet and disperse it. While stirring, potassium silicate and dispersant were added, and the stirring speed was adjusted to 500 rpm and stirred for 30 minutes to obtain the base slurry. While stirring, hollow glass microspheres and mica powder were added to the base slurry in sequence and dispersed at high speed of 1500 rpm for 15 minutes using a high-speed disperser. The stirring speed was reduced to 400 rpm and added slowly. Acrylic emulsion was added slowly and stirred at low speed for 15 minutes. Defoamer was added and stirring was continued for 8 minutes. Impurities were removed by passing through a 120-mesh sieve to obtain the coating.

[0058] Comparative Example 2

[0059] This comparative example provides an inorganic thermal insulation intermediate coating and its preparation method. The composition and preparation method of the coating are the same as in Example 1, except that the hollow glass microspheres are epoxidized hollow glass microspheres.

[0060] The preparation method of epoxidized hollow glass microspheres includes: dispersing 100g of hollow glass microspheres in 1000ml of ethanol, ultrasonically dispersing for 15min, adding 5.5g of γ-glycidoxypropyltrimethoxysilane dropwise under nitrogen protection, heating to 80℃ and reacting for 4.5h, centrifuging after the reaction (3000rpm, 10min), washing three times with anhydrous ethanol, and vacuum drying to obtain epoxidized hollow glass microspheres.

[0061] Comparative Example 3

[0062] This comparative example provides an inorganic thermal insulation intermediate coating and its preparation method. The composition and preparation method of the coating are the same as in Example 1, except that the preparation method of the mica functional filler includes:

[0063] (1) Add 100g of mica powder to a 1.5mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stir at 45℃ for 2.5h, filter, wash with deionized water until neutral, and dry to obtain pretreated mica powder; disperse 100g of pretreated mica powder in 1000ml of anhydrous ethanol, sonicate for 15min to obtain a suspension, add 23g of concentrated phosphoric acid (mass percentage of 85% H3PO4) and 18g of melamine, stir for 30min, and dry to obtain a mixture;

[0064] (2) Place the mixture in a tube furnace, introduce nitrogen (flow rate 200 mL / min), raise the temperature to 150℃ at a rate of 5℃ / min and hold for 1.3 h; continue to raise the temperature to 290℃ at a rate of 3℃ / min and hold for 2.5 h, cool naturally to room temperature, grind and sieve to obtain mica functional filler.

[0065] Comparative Example 4

[0066] This comparative example provides an inorganic thermal insulation intermediate coating and its preparation method. The composition and preparation method of the coating are the same as in Example 1, except that the mica functional filler is not subjected to high-temperature calcination. The preparation method includes: adding 100g of mica powder to a 1.5mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stirring at 45℃ for 2.5h, filtering, washing with deionized water until neutral, and drying to obtain pretreated mica powder; grinding 10g of boric acid and 6g of zinc oxide in an agate mortar for 30min, dispersing in 1000ml of anhydrous ethanol, and ultrasonically dispersing for 15min to obtain a suspension; adding 100g of pretreated mica powder to the suspension, mechanically stirring for 30min, adding 23g of concentrated phosphoric acid (mass percentage of 85% H3PO4) and 18g of melamine, stirring for 30min, and drying to obtain a mixture, which is the mica functional filler.

[0067] Comparative Example 5

[0068] This comparative example provides an inorganic thermal insulation intermediate coating and its preparation method. The composition and preparation method of the coating are the same as in Example 1, except that the preparation method of the mica functional filler includes:

[0069] (1) Add 100g of mica powder to a 1.5mol / L hydrochloric acid solution (solid-liquid ratio 1:10), stir at 45℃ for 2.5h, filter, wash with deionized water until neutral, and dry to obtain pretreated mica powder; grind 10g of boric acid and 6g of zinc oxide in an agate mortar for 30min, disperse in 1000ml of anhydrous ethanol, and sonicate for 15min to obtain a suspension; add 100g of pretreated mica powder to the suspension, stir mechanically for 30min to obtain a mixture;

[0070] (2) Place the mixture in a tube furnace, introduce nitrogen (flow rate 200 mL / min), raise the temperature to 150℃ at a rate of 5℃ / min and hold for 1.3 h; continue to raise the temperature to 290℃ at a rate of 3℃ / min and hold for 2.5 h, cool naturally to room temperature, grind and sieve to obtain mica functional filler.

[0071] Performance testing

[0072] The inorganic coatings prepared in the examples and comparative examples were sprayed onto the surface of surface-treated steel plates, with a coating thickness of 200-300 μm. After curing for 120 h, the thermal conductivity, aging resistance, and oxygen index were tested. The bonding strength was tested according to standard GB / T9779-2015, the thermal conductivity according to standard GB / T10295, the oxygen index according to standard GB / T2406.2-2009, and the aging resistance according to standard GB / T 14522-2008. The test results are shown in Table 1.

[0073] Table 1 Performance Test Results

[0074]

[0075] The above test results show that the inorganic thermal insulation intermediate coating provided by the present invention has excellent comprehensive performance. While maintaining good thermal insulation performance, it also has good anti-aging and flame retardant properties.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An inorganic thermal insulation intermediate coating, characterized in that, The product comprises the following components by weight: 20-25 parts inorganic resin, 10-15 parts aerogel, 10-13 parts modified hollow glass microspheres, 1-3 parts mica functional filler, 5-10 parts emulsion, 0.5-0.8 parts dispersant, 0.1-0.2 parts defoamer, and 20-30 parts water. The modified hollow glass microspheres are γ-butylselenolactone-modified hollow glass microspheres; the mica functional filler is a ternary composite mica filler of boron, zinc, and phosphorus. The inorganic resin is potassium silicate, and the emulsion is an acrylic emulsion. The preparation method of the mica functional filler includes: B1. Grind and mix boric acid and zinc oxide, disperse in anhydrous ethanol to obtain a suspension; add pretreated mica powder to the suspension, stir and mix, add concentrated phosphoric acid and melamine, stir for 30 min, dry to obtain a mixture; B2. The mixture is first heated to 120-180℃ and held for 1-1.5h under nitrogen protection, and then heated to 280-300℃ and held for 2-3h to obtain mica functional filler. The preparation method of pretreated mica powder includes: adding mica powder to a 1-2 mol / L hydrochloric acid solution, stirring at 40-50℃ for 2-3 hours, filtering and drying to obtain pretreated mica powder; In step B2, the mass ratio of pretreated mica powder, boric acid, and zinc oxide is 1:0.08-0.12:0.04-0.08, the amount of concentrated phosphoric acid added is 20-25% of the mass of pretreated mica powder, and the amount of melamine added is 15-20% of the mass of pretreated mica powder.

2. The inorganic thermal insulation intermediate coating as described in claim 1, characterized in that: The method for preparing the modified hollow glass microspheres includes: A1. Hollow glass microspheres were dispersed in ethanol and ultrasonically dispersed. γ-glycidoxypropyltrimethoxysilane was added dropwise. The mixture was reacted at 70-90℃ for 4-5 hours under nitrogen protection to obtain epoxidized hollow glass microspheres. A2. Epoxidized hollow glass microspheres were dispersed in anhydrous tetrahydrofuran, and γ-butylselenolactone and 4-dimethylaminopyridine were added. The mixture was reacted at 25-30℃ for 0.5-1h under nitrogen protection to obtain modified hollow glass microspheres.

3. The inorganic thermal insulation intermediate coating as described in claim 2, characterized in that: In step A1, the mass ratio of hollow glass microspheres to γ-glycidoxypropyltrimethoxysilane is 1:0.03-0.08; in step A2, the mass ratio of epoxidized hollow glass microspheres, γ-butylselenolactone, and 4-dimethylaminopyridine is 100:4-8:0.6-0.

8.

4. The inorganic thermal insulation intermediate coating as described in claim 1, characterized in that: The dispersant is sodium polycarboxylate, and the defoamer is an organosilicon defoamer.

5. The method for preparing an inorganic thermal insulation intermediate coating as described in any one of claims 1-4, characterized in that: Includes the following steps: S1. Add the aerogel to water and stir to disperse it. Then, while stirring, continue to add the inorganic resin and dispersant and stir for 20-40 minutes to obtain the basic slurry. S2. Under stirring, add modified hollow glass microspheres and mica functional filler to the base slurry, disperse at 1500 rpm for 10-20 min, then add emulsion, reduce stirring speed to 400 rpm and stir for 10-20 min, add defoamer, and continue stirring for 5-10 min to obtain the coating.

6. The application of the inorganic thermal insulation intermediate coating as described in any one of claims 1-4, characterized in that: The inorganic thermal insulation intermediate coating is applied in the field of thermal insulation boards.

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