A polybutyl acrylate modified silicone rubber based temperature resistant thermal insulation coating and a preparation method thereof

Abstract

The application discloses a kind of polybutyl acrylate modified silicone rubber base temperature-resistant heat-insulating coating, which is made of the following ingredients by mass fraction: alpha, omega-dihydroxyl terminated polydimethylsiloxane 100 parts, butyl acrylate 20~40 parts, 2-hydroxy-2-methyl-1-phenyl-1-propanone 0.5~1 part, KY-405, KY-01 or alkylated phenothiazine 1~2 parts, hollow glass microsphere 17.5~40 parts, dibutyltin dilaurate 2 parts, tetraethyl orthosilicate 5 parts;The preparation method of the coating is: adding photoinitiator and reactive diluent into base glue, stirring under ultraviolet light, adding the remaining ingredients in turn, stirring evenly, then brushing and curing. The coating of the application uses butyl acrylate as a reactive diluent, inhibits the increase of system viscosity, increases the addition amount of heat-insulating filler, and improves the temperature resistance and heat-insulating performance of the coating. The preparation method of the application is simple, environmentally friendly and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat-resistant and heat-insulating coating preparation, and specifically relates to a polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating and a preparation method thereof. Background Art

[0002] High-temperature boilers, steam pipes, and other applications require heat-resistant and insulating coatings to reduce heat loss. Room-temperature vulcanized silicone rubber, a polymer-based coating material with relatively excellent temperature resistance, can generally be used for extended periods in temperatures ranging from -60°C to 220°C. Its thermal conductivity is approximately 0.18W / mK, but its performance is insufficient to meet the heat insulation requirements of metal surfaces in extreme environments.

[0003] Adding lightweight, low-thermal-conductivity fillers such as hollow glass microspheres is the main way to improve its thermal insulation performance. Chinese patent CN114561103A discloses a method for improving the thermal insulation performance of composite silicone rubber by adding hollow glass microspheres, cork powder, hollow wood powder and other fillers to silicone rubber. After adding 18phr of hollow glass microspheres, the thermal conductivity of silicone rubber is reduced to below 0.14W / mK. Increasing the amount of filler added is expected to continue to improve thermal insulation performance. However, due to the low density of hollow glass microspheres, the viscosity of the composite system increases sharply after introducing them into silicone rubber, which seriously affects the subsequent processability of the composite silicone rubber. Taking 107 silicone rubber with a density of 5000mPa·s as an example, when the bulk density of hollow glass microspheres is 0.08g / cm 3 and 0.18g / cm 3 When the maximum addition amount is 10 phr and 20 phr, respectively, the thermal conductivity of the resulting composite silicone rubber is only 0.125 W / mK and 0.139 W / mK. Therefore, it is difficult to further improve the thermal insulation performance of composite silicone rubber by increasing the filler addition amount. Existing technologies increase the filler addition amount by adding diluents such as organic solvents and low-viscosity silicone oil to 107 rubber. However, organic solvents are volatile and have poor environmental protection, and adding low-viscosity silicone oil is expensive. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the above-mentioned prior art and provide a heat-resistant and heat-insulating coating based on polybutyl acrylate-modified silicone rubber. This heat-resistant and heat-insulating coating directly utilizes butyl acrylate, the raw material for the polymerization of polybutyl acrylate, as a reactive diluent. Through short-chain polymerization of butyl acrylate and in-situ dispersion of the resulting polybutyl acrylate, the increase in system viscosity is effectively suppressed, facilitating the introduction of large quantities of hollow glass microspheres, a heat-insulating filler, thereby improving the coating's heat resistance and heat-insulating properties while avoiding the use of toxic organic solvents and reducing costs.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating, characterized in that it is made of the following components in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 20 to 40 parts of butyl acrylate, 0.5 to 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1 to 2 parts of KY-405, KY-01 or alkylated phenothiazine, 17.5 to 40 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0006] The above-mentioned polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is characterized in that it is made of the following components in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 30 parts of butyl acrylate, 0.75 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts of KY-01, 17.5 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0007] In addition, the present invention also discloses a method for preparing the polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating as described above, characterized in that the method comprises the following steps:

[0008] Step 1: adding 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane, stirring and reacting under ultraviolet light to obtain a blend;

[0009] Step 2: Add KY-405, KY-01 or alkylated phenothiazine, hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate to the blend obtained in step 1 in sequence, stir and mix evenly, and then apply it on the surface of the sandblasted metal part. After standing and curing, a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is formed.

[0010] The above method is characterized in that the viscosity of the α,ω-dihydroxy-terminated polydimethylsiloxane in step 1 is 5000 mPa·s, the intensity of the ultraviolet light is 90 mW / cm 2 The stirring speed of the stirring reaction is 300 rpm and the stirring time is 10 min.

[0011] The above method is characterized in that the bulk density of the hollow glass microspheres in step 2 is 0.08 g / cm 3 ~0.18g / cm 3The stirring and mixing speed is 300 rpm, and the time is 5 minutes. The curing condition is to stand and cure at room temperature for more than 12 hours. The greater the bulk density of the hollow glass microspheres, the worse the thermal insulation performance, which is not conducive to improving the thermal insulation performance of the composite rubber, but the maximum filling amount is also larger. The present invention controls the bulk density of the hollow glass microspheres, while ensuring the thermal insulation performance of the rubber-based heat-resistant thermal insulation coating, and increases the maximum filling amount of the hollow glass microspheres, thereby increasing its maximum filling amount by 75% to 100%, and reducing the thermal conductivity of the coating by 8.5% to 12.5%.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. Compared with the existing technology that uses organic solvent-type or silicone oil-type diluents to increase the amount of filler added to silicone rubber, which leads to poor environmental protection and high cost, the present invention uses butyl acrylate as a reactive diluent and induces in-situ polymerization of butyl acrylate through ultraviolet light. It not only avoids the environmental problems caused by the use of organic solvent-type diluents, but also the cost is only about 1 / 5 of that of using silicone oil-type diluents.

[0014] 2. Compared with the prior art in which a long chain of polybutyl acrylate is first prepared by bulk polymerization and then the viscous polybutyl acrylate is blended with α,ω-dihydroxy-terminated polydimethylsiloxane to prepare a polybutyl acrylate modified silicone rubber-based coating, the polybutyl acrylate has strong viscosity and high viscosity, which makes it difficult to blend with α,ω-dihydroxy-terminated polydimethylsiloxane, the dispersion after compounding is poor, and the further introduction of thermal insulation fillers is seriously affected, thereby limiting the improvement of the heat insulation performance and temperature resistance of the coating. In the present invention, a photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone and a reactive diluent butyl acrylate are first added to α,ω-dihydroxy-terminated polydimethylsiloxane for ultraviolet light irradiation. According to the in-situ polymerization of polybutyl acrylate, heat-resistant agent KY-405, KY-01 or alkylated phenothiazine, thermal insulation filler hollow glass microspheres, catalyst dibutyltin dilaurate, cross-linking agent ethyl orthosilicate are added in sequence for curing to form a coating. Butyl acrylate is pre-dispersed into the base rubber and then polymerized to generate polybutyl acrylate. The hindering effect of α, ω-dihydroxy-terminated polydimethylsiloxane is utilized to realize the short-chain polymerization of butyl acrylate and the in-situ dispersion of the product polybutyl acrylate. While realizing the modification of the base rubber with polybutyl acrylate to improve the temperature resistance, the increase of the viscosity of the system is effectively suppressed, thus solving the problem that the thermal insulation performance of the coating is limited due to the high viscosity of polybutyl acrylate, which leads to the low amount of thermal insulation filler introduced.

[0015] 3. Compared with the direct contact failure temperature of α,ω-dihydroxy-terminated polydimethylsiloxane silicone rubber (the heat source temperature at which the material undergoes blistering, softening, and fracture when in direct contact with the heat source for 30 minutes) of about 235°C, the direct contact failure temperature of the heat-resistant thermal insulation coating of the present invention is increased to above 275°C, the maximum addition amount of the thermal insulation filler hollow glass microspheres in the coating is increased by 75% to 100%, and the thermal conductivity of the coating is reduced by 8.5% to 12.5%.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a physical picture of the contact surface of the polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating prepared in Example 1 of the present invention after being directly placed on a 275°C hot plate for 30 minutes.

[0018] Figure 2 This is a physical picture of the contact surface of the polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating prepared in Comparative Example 1 of the present invention after being directly placed on a 235°C hot plate for 30 minutes.

[0019] Figure 3 This is a physical picture of the contact surface of the polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating prepared in Comparative Example 2 of the present invention after being directly placed on a 265°C hot plate for 30 minutes. DETAILED DESCRIPTION

[0020] Example 1

[0021] The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating of this embodiment is made of the following components in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 20 parts of butyl acrylate, 0.5 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1 part of KY-405, 30 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0022] The preparation method of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating of this embodiment comprises the following steps:

[0023] Step 1: Add 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s at an intensity of 90 mW / cm 2 The mixture was stirred at 300 rpm under ultraviolet light for 10 min to obtain a blend;

[0024] Step 2: Add KY-405 and a bulk density of 0.18 g / cm 3Hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate are stirred at a speed of 300 rpm for 5 minutes to mix evenly, and then brushed on the surface of the metal sandblasted part. After standing and curing in air at room temperature for 12 hours, a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is formed.

[0025] The sample of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating prepared in this example was placed directly on a temperature-stable hot table for 30 minutes to test its direct contact failure temperature. The results are as follows: Figure 1 As shown, from Figure 1 It can be seen that after the polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating was placed on a 275°C hot plate for 30 minutes, no blistering, softening, or cracking occurred on the contact surface.

[0026] Example 2

[0027] The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating of this embodiment is made of the following components in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 30 parts of butyl acrylate, 0.75 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts of KY-01, 17.5 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0028] The preparation method of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating of this embodiment comprises the following steps:

[0029] Step 1: Add 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s at an intensity of 90 mW / cm 2 The mixture was stirred at 300 rpm under ultraviolet light for 10 min to obtain a blend;

[0030] Step 2: Add KY-01 and a bulk density of 0.08 g / cm 3 Hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate are stirred at a speed of 300 rpm for 5 minutes to mix evenly, and then brushed on the surface of the metal sandblasted part. After standing and curing in air at room temperature for 12 hours, a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is formed.

[0031] Example 3

[0032] The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating of this embodiment is made of the following components in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 40 parts of butyl acrylate, 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts of alkylated phenothiazine, 40 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0033] The preparation method of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating of this embodiment comprises the following steps:

[0034] Step 1: Add 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s at an intensity of 90 mW / cm 2 The mixture was stirred at 300 rpm under ultraviolet light for 10 min to obtain a blend;

[0035] Step 2: To the blend obtained in step 1, alkylated phenothiazine and a bulk density of 0.18 g / cm 3 Hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate are stirred at a speed of 300 rpm for 5 minutes to mix evenly, and then brushed on the surface of the metal sandblasted part. After standing and curing in air at room temperature for 12 hours, a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is formed.

[0036] Comparative Example 1

[0037] The silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is made of the following ingredients in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0038] The preparation method of the silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is specifically as follows: dibutyltin dilaurate and ethyl orthosilicate are sequentially added to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s, stirred at a speed of 300 rpm for 5 minutes to mix evenly, and then brushed on the surface of the sandblasted metal part. The mixture is allowed to stand and cure in air at room temperature for 12 hours to form a polybutyl acrylate-modified silicone rubber-based heat-resistant and heat-insulating coating.

[0039] The sample of the silicone rubber-based heat-resistant and heat-insulating coating prepared in this comparative example was placed directly on a temperature-stable hot table for 30 minutes, and its direct contact failure temperature was tested. The results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the contact surface of the silicone rubber-based temperature-resistant and heat-insulating coating has directly broken after being placed on a 235°C hot plate for 30 minutes.

[0040] Comparative Example 2

[0041] The silicone rubber-based temperature-resistant and heat-insulating coating of this comparative example is made of the following ingredients in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 40 parts of butyl acrylate, 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0042] The preparation method of the silicone rubber-based heat-resistant and heat-insulating coating of this comparative example comprises the following steps:

[0043] Step 1: Add 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s at an intensity of 90 mW / cm 2 The mixture was stirred at 300 rpm under ultraviolet light for 10 min to obtain a blend;

[0044] Step 2: Add dibutyltin dilaurate and ethyl orthosilicate to the blend obtained in step 1 in sequence, stir at 300 rpm for 5 minutes to mix evenly, and then apply it on the surface of the sandblasted metal part. Let it stand in air at room temperature and cure for 12 hours to form a silicone rubber-based temperature-resistant and heat-insulating coating.

[0045] The sample of the silicone rubber-based heat-resistant and heat-insulating coating prepared in this comparative example was placed directly on a temperature-stable hot table for 30 minutes, and its direct contact failure temperature was tested. The results are as follows: Figure 3 As shown, from Figure 3 It can be seen that after the silicone rubber-based temperature-resistant and heat-insulating coating was placed on a 265°C hot plate for 30 minutes, the contact surface only showed slight yellowing, without any blistering, softening, or breakage.

[0046] Comparative Example 3

[0047] The silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is made of the following ingredients in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 2 parts of KY-01, 10 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0048] The preparation method of the silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is as follows: KY-01, a bulk density of 0.08 g / cm 3 Hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate were added to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000mPa·s. The mixture was stirred at 300rpm for 5min to mix evenly, and then brushed on the surface of the sandblasted metal part. The mixture was left to stand and cure in air at room temperature for 12h to form a silicone rubber-based temperature-resistant and heat-insulating coating.

[0049] Comparative Example 4

[0050] The silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is made of the following ingredients in parts by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 2 parts of KY-01, 20 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

[0051] The preparation process of the silicone rubber-based heat-resistant and heat-insulating coating of this comparative example is as follows: KY-01, a bulk density of 0.18 g / cm 3 Hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate were added to α,ω-dihydroxy-terminated polydimethylsiloxane with a viscosity of 5000mPa·s. The mixture was stirred at 300rpm for 5min to mix evenly, and then brushed on the surface of the sandblasted metal part. The mixture was left to stand and cure in air at room temperature for 12h to form a silicone rubber-based temperature-resistant and heat-insulating coating.

[0052] The thermal conductivity of the temperature-resistant thermal insulation coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention was tested using a transient hot wire method. Samples of each temperature-resistant thermal insulation coating were placed directly on a temperature-stable hot surface to test their direct contact failure temperatures. The results are shown in Table 1 below.

[0053]

[0054] In Table 1, the “-” in the bulk density column indicates that no insulating hollow glass microspheres were added, so no data is available. The “-” in the direct contact failure temperature column indicates that the direct contact failure temperature of the sample could not be directly measured, so no data is available. The test results should be referred to the notes. The “-” in the notes column indicates that the direct contact failure temperature of the sample has been measured, so no content is available.

[0055] As can be seen from Table 1, the heat resistance of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coatings prepared by the present invention is good, and is superior to the silicone rubber-based heat-resistant and heat-insulating coatings prepared in Comparative Examples 1 to 4. Among them, the direct contact failure temperature of the silicone rubber-based heat-resistant and heat-insulating coating prepared in Comparative Example 2 is more than 35°C higher than that of Comparative Example 1, indicating that the preparation method of the present invention of simultaneously introducing butyl acrylate and a photoinitiator into the base rubber improves the heat resistance of the coating, and the direct contact failure temperature of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating prepared in Example 3 can continue to be increased to above 275°C. It is higher than that of Comparative Example 2, which shows that the preparation method of the present invention can introduce heat-resistant agents and heat-resistant fillers, further improving the temperature resistance of the coating; at the same time, by comparing the thermal conductivity of Example 2 and Example 3, Comparative Example 3 and Comparative Example 4, it can be seen that the present invention introduces butyl acrylate into the base glue, which is beneficial to reducing the viscosity of the system and greatly increases the addition amount of heat-resistant filler hollow glass microspheres, the maximum addition amount is increased by 75%~100%, the thermal conductivity of the coating is reduced by 8.5%~12.5%, and the minimum thermal conductivity of the coating can reach 0.1101W / mK, which significantly improves the thermal insulation performance of the coating.

[0056] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating, characterized in that: It is made from the following ingredients by mass: 100 parts of α,ω-dihydroxy-terminated polydimethylsiloxane, 20-40 parts of butyl acrylate, 0.5-1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-2 parts of KY-405, KY-01 or alkylated phenothiazine, 17.5-40 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate; The preparation method of the polybutyl acrylate modified silicone rubber-based heat-resistant and heat-insulating coating comprises the following steps: Step 1: adding 2-hydroxy-2-methyl-1-phenyl-1-propanone and butyl acrylate to α,ω-dihydroxy-terminated polydimethylsiloxane, stirring and reacting under ultraviolet light to obtain a blend; Step 2: Add KY-405, KY-01 or alkylated phenothiazine, hollow glass microspheres, dibutyltin dilaurate and ethyl orthosilicate to the blend obtained in step 1 in sequence, stir and mix evenly, and then apply it on the surface of the sandblasted metal part. After standing and curing, a polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating is formed.

2. The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating according to claim 1, characterized in that: The invention is prepared from the following ingredients in parts by mass: 100 parts of α,ω dihydroxy-terminated polydimethylsiloxane, 30 parts of butyl acrylate, 0.75 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts of KY-01, 17.5 parts of hollow glass microspheres, 2 parts of dibutyltin dilaurate, and 5 parts of tetraethyl orthosilicate.

3. The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy-terminated polydimethylsiloxane in step 1 is 5000 mPa·s, and the intensity of the ultraviolet light is 90 mW / cm 2 The stirring speed of the stirring reaction is 300 rpm and the stirring time is 10 min.

4. The polybutyl acrylate modified silicone rubber-based temperature-resistant and heat-insulating coating according to claim 1, characterized in that: The bulk density of the hollow glass microspheres in step 2 is 0.08 g / cm 3 ~0.18g / cm 3 The stirring speed for uniform mixing is 300 rpm, and the time is 5 minutes. The curing condition is to stand and cure at room temperature for more than 12 hours.

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