A high temperature resistant low toxicity spray paint and preparation method thereof

Abstract

The present invention relates to a kind of high temperature resistant low toxicity spray paint and preparation method thereof, comprising feed liquid and dimethyl ether, the feed liquid comprises the following components: by weight fraction, 20-30 parts of methyl silicone resin, 5-15 parts of high temperature resistant pigment, 15-30 parts of secondary film-forming particles, 0.1-0.2 parts of leveling agent, 0.06-0.1 parts of dispersant, 0.5-2.5 parts of anti-settling agent and 40-60 parts of diluent, the secondary film-forming particles comprise phenyl silicone resin and low melting point glass powder dispersed and fixed to the phenyl silicone resin, and the mass ratio of the phenyl silicone resin to the low melting point glass powder is 1:(0.5-1.5). The above-mentioned spray paint has good leveling performance, can form a uniform coating on the surface of the substrate, and has good heat resistance, and the coating can form a uniform secondary film at high temperature.

Description

Technical Field

[0001] The invention relates to the field of organic silicon resin spray paint, in particular to a high temperature resistant and low toxicity spray paint and a preparation method thereof. Background Art

[0002] Silicone resin is a cross-linked semi-inorganic polymer with Si-O-Si as the main chain and organic groups attached to silicon atoms. It is formed by hydrolysis and polycondensation of multifunctional organosilanes. It can be further transformed into a thermosetting resin with a three-dimensional structure and insoluble and infusible when heated or in the presence of a catalyst. The molecular chain structure of conventional silicone resin will become more relaxed at high temperatures, and the interaction between molecules will weaken, resulting in a decrease in hardness. In addition, silicone resin will undergo thermal oxidation degradation at high temperatures, producing volatile substances and having certain toxicity.

[0003] The addition of low-melting-point glass powder is beneficial to improving the high-temperature resistance of silicone resin. The low-melting-point glass powder can adhere well to the decomposition residue and pigment of silicone resin in a molten state to form a dense high-temperature resistant coating, thereby preventing the silicone resin from further thermal oxidation decomposition. CN115746700A discloses a high-temperature resistant mold release coating, which includes the following components by weight: 45-80 parts of silicone resin, 4-20 parts of solvent, 0.1-1 part of dispersant, 0.1-1 part of defoamer, 0.4-2 parts of anti-settling agent, 1-6 parts of polytetrafluoroethylene powder, 5-17 parts of talcum powder, 3-10 parts of glass powder, 3-8 parts of silicon carbide, and 1-3 parts of carbon black. The release coating formula involves organic-inorganic hybrid resin technology, utilizes the strong heat resistance of silicone resin, makes the silicone resin form a highly cross-linked and more stable spatial network inorganic structure, and can also react with the siloxy group of the filler to prevent further breakage of the main chain. The low-melting-point glass powder is then used for secondary film formation and further hybridized with silicone resin to form a dense and wear-resistant coating. Finally, the paint film is converted into inorganic paint so that the paint film can adapt to the heat resistance at different temperatures. Although the low-melting-point glass powder can improve the high-temperature resistance of the coating through the above-mentioned effects, the properties of the low-melting-point glass powder itself lead to other problems. If a large amount of low-melting-point glass powder is added, the glass powder flows along the surface of the substrate under the action of gravity after melting, resulting in pores in some areas of the coating, and it is impossible to form a secondary film to form a high-temperature resistant coating, resulting in a decrease in the high-temperature and corrosion resistance of the coating; if a small amount of low-melting-point glass powder is added, it is difficult to form a uniform and dense high-temperature resistant coating.

[0004] Therefore, it is necessary to provide a high temperature resistant low toxicity spray paint and a preparation method thereof. Summary of the invention

[0005] In order to solve the problem that silicone spray paint is not resistant to high temperatures and releases volatile substances at high temperatures, it is necessary to provide a high temperature resistant and low toxicity spray paint and a preparation method thereof.

[0006] A high temperature resistant and low toxicity spray paint comprises a slurry and dimethyl ether, wherein the slurry comprises the following components: in weight fraction, 20-30 parts of methyl silicone resin, 5-15 parts of high temperature resistant pigment, 15-30 parts of secondary film-forming particles, 0.1-0.2 parts of leveling agent, 0.06-0.1 parts of dispersant, 0.5-2.5 parts of anti-settling agent and 40-60 parts of diluent, wherein the secondary film-forming particles comprise phenyl silicone resin and low melting point glass powder dispersed and fixed on the phenyl silicone resin, and the mass ratio of the phenyl silicone resin to the low melting point glass powder is 1:(0.5-2).

[0007] The above-mentioned high-temperature resistant and low-toxic spray paint has good leveling performance and can form a uniform coating on the surface of the substrate. The low-melting-point glass powder fixed inside the phenyl silicone resin will not be deposited at the bottom of the coating. When the coating is faced with a high temperature of more than 400°C, under the protection of the low-melting-point glass powder, the phenyl silicone resin inside the secondary film-forming particles will not come into contact with oxygen to undergo thermal oxidation degradation, thereby having a slower decomposition rate. The molten low-melting-point glass powder slowly seeps out from the surface of the secondary film-forming particles and forms a secondary film with the surrounding pigments and decomposition products of the methyl silicone resin to repair cracks. No pores will be generated in situ due to the flow of the molten glass powder, resulting in thermal oxidation degradation of the resin in situ.

[0008] Preferably, the size of the secondary film-forming particles is 20-50 μm. If the secondary film-forming particles with smaller particle sizes are used, the phenyl silicone resin inside the particles cannot be well protected; if the secondary film-forming particles with larger particle sizes are used, the seepage of the low-melting-point glass powder will be affected, affecting the repairing effect of the low-melting-point glass powder on the coating.

[0009] Preferably, the particle size of the low melting point glass powder is 1-1.5 μm. The use of the low melting point glass powder with the above particle size can better protect the phenyl silicone resin and produce a more uniform secondary film.

[0010] Preferably, the melting point of the low melting point glass powder is 350-400° C. Using glass powder with a lower melting point can convert it into a molten state at a lower temperature to avoid the phenyl silicone resin itself being degraded in large quantities at too high a temperature, and the glass powder being separated and flowing to other areas under the action of gravity, thereby failing to produce uniform secondary film formation.

[0011] Preferably, the raw materials of the low-melting glass powder include silicon dioxide, phosphorus pentoxide and boron trioxide. The low-melting glass powder has a relatively low melting point and can form a chemical bond with the phenyl silicone resin to provide the phenyl silicone resin with heat resistance.

[0012] Preferably, the preparation method of the secondary film-forming particles comprises: mixing the phenyl silicone resin and the low-melting-point glass powder in a mixer, and then extruding at 90-100° C., crushing and sieving to obtain the secondary film-forming particles. In the above manner, the low-melting-point glass powder and the phenyl silicone resin can be uniformly mixed, and secondary film-forming particles with uniform particle size can be obtained.

[0013] Preferably, the mass ratio of the phenyl silicone resin to the low-melting-point glass powder is 1:(1-1.5).

[0014] Preferably, the thermal decomposition temperature of the phenyl silicone resin is ≥ 320° C. A phenyl silicone resin with a higher decomposition temperature is used to prevent the secondary film-forming particles from decomposing before the methyl silicone resin during the coating temperature rise process.

[0015] Preferably, the diluent comprises acetone.

[0016] The second aspect of the present invention provides a method for preparing a high temperature resistant and low toxic spray paint, comprising the following steps: weighing phenyl silicone resin and low melting point glass powder, mixing them in a mixer, then extruding them at 90-100° C., and then crushing and sieving to obtain secondary film-forming particles.

[0017] Weigh methyl silicone resin, high temperature resistant pigment, secondary film-forming particles, leveling agent, dispersant, anti-settling agent and diluent according to the components, put the methyl silicone resin in a blender and stir evenly, then add the secondary film-forming particles and stir evenly, then add the other components of the slurry and stir evenly, then filter to obtain the slurry, fill the slurry into an aerosol can with glass beads in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling.

[0018] The spray paint obtained by the above preparation method has good leveling performance, can form a uniform coating on the surface of the substrate, and has good heat resistance. The coating can form a uniform secondary film at high temperature. DETAILED DESCRIPTION

[0019] For ease of understanding of the application, the application will be described more fully below. The application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the application more thorough and comprehensive.

[0020] Example 1

[0021] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrusion at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0022] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0023] Example 2

[0024] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 50μm by a crusher, and filtered through a 300-mesh sieve to obtain secondary film-forming particles.

[0025] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0026] Example 3

[0027] Preparation of secondary film-forming particles: Weigh 30g of phenyl silicone resin (Sihai brand 9611) and 30g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0028] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0029] Example 4

[0030] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.5μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0031] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.24g of dispersant Bick-P104S and 10g of anti-settling agent natural montmorillonite were added, and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 80 after stirring evenly. 0r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into the aerosol can with glass beads, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0032] Example 5

[0033] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 20g of low-melting point glass powder (average particle size 1μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0034] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0035] Example 6

[0036] Preparation of secondary film-forming particles: Weigh 20g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0037] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0038] Example 7

[0039] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 4μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrude at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0040] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0041] Example 8

[0042] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrusion at 100℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 20μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0043] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0044] Example 9

[0045] Preparation of secondary film-forming particles: Weigh 40g of phenyl silicone resin (Sihai brand 9611) and 40g of low-melting point glass powder (average particle size 1.3μm, Anmi Micronano GT35, melting point 350℃, containing silicon dioxide, phosphorus pentoxide and boron trioxide), transfer them to a high-speed mixer for mixing, and then transfer them to an extruder for extrusion at 90℃. After the extrudate is naturally cooled to room temperature, the extrudate is broken into particles with an average particle size of 100μm by a crusher, and filtered through a 500-mesh sieve to obtain secondary film-forming particles.

[0046] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then the secondary film-forming particles were added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant BYK-P104S and 2g of anti-settling agent natural montmorillonite were added and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800 after stirring evenly. r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing secondary film-forming particles, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into an aerosol can with glass beads placed in it, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0047] Comparative Example 1

[0048] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, stirred at 800r / s for 10min, and then 20g of low-melting-point glass powder (average particle size 20μm, Anmi Micronano GT35, melting point 350°C) was added and stirred for 20min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant Bick-P104S and 2g of anti-settling agent natural montmorillonite were added, and stirred evenly at 500r / s, and the high-temperature resistant pigment iron chrome black was added while maintaining the speed. After stirring evenly, increase the speed to 800r / s, continue stirring for 0.5h, and then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste to the slurry containing low-melting point glass powder, and then add acetone and leveling agent German BYK leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into the aerosol can with glass beads, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0049] Comparative Example 2

[0050] Preparation of spray paint: 60g of methyl silicone resin (JP-XHL5201, Tangyi Chemical) was weighed and placed in a blender, and stirred at 800r / s for 10min; 20g of methyl silicone resin was weighed and placed in another blender, and then 0.4g of dispersant Bick-P104S and 2g of anti-settling agent natural montmorillonite were added, and stirred evenly at 500r / s. The high temperature resistant pigment iron chrome black was added at this speed, and the speed was increased to 800r / s after stirring evenly, and stirring was continued for 0. 5h, then grind to obtain color paste, and then test the color paste by scraping fineness to obtain color paste with qualified scraping fineness; add the color paste into the slurry containing 60g methyl silicone resin, and then add acetone and leveling agent BYK333 in turn, and then spray the plate to adjust the color until the color is qualified; filter the toned liquid, and then fill the liquid into the aerosol can with glass beads, and then seal the aerosol can. After sealing, fill dimethyl ether into the aerosol can by pressure filling method.

[0051] The spray paints prepared in the above embodiments and comparative examples were subjected to performance tests, heat resistance tests were performed according to GB / T1735-2009, and heat resistance and salt spray tests were performed according to the standard of HG / T 5174-2017. The test results are as follows:

[0052] As shown in Table 1.

[0053]

[0054]

[0055] According to the data in Table 1, the spray paint of Examples 1-6 has stronger high temperature resistance than that of Comparative Example 1, and can maintain better corrosion resistance after high temperature treatment. This is because the high temperature resistant and low toxicity spray paint of Examples 1-6 uses secondary film-forming particles, and the low melting point glass powder fixed inside the phenyl silicone resin will not be deposited at the bottom of the coating. When the coating is faced with a high temperature of more than 400°C, under the protection of the low melting point glass powder, the phenyl silicone resin inside the secondary film-forming particles will not come into contact with oxygen to undergo thermal oxidation degradation, thereby having a slower decomposition rate. The molten low melting point glass powder slowly seeps out from the surface of the secondary film-forming particles and forms a secondary film with the surrounding pigments and methyl silicone resin decomposition products to repair cracks. Pores will not be generated in situ due to the flow of the molten glass powder, causing thermal oxidation degradation of the resin in situ. Comparative Example 1 uses conventional low-melting point glass powder. Although the heat resistance and corrosion resistance are improved compared with Comparative Example 2, on the one hand, due to the large density of the glass powder, it will settle to the bottom during the coating curing process, resulting in more pores at the bottom of the coating, making it easy for oxygen to enter the coating and contact with the methyl silicone resin, causing the latter to be thermally oxidatively degraded. On the other hand, during the high-temperature melting process, the glass powder with a higher addition amount and particle size will form a flow channel inside the coating after melting, causing the glass powder to flow and generate pores in situ, which in turn makes the resin in situ susceptible to thermally oxidative degradation.

[0056] Example 9 has a moderate number of cracks because it uses secondary film-forming particles with larger particle sizes, which excessively affect the fluidity of the low-melting-point glass powder and reduce the repair ability. Example 6 uses a lower proportion of phenyl silicone resin, and part of the low-melting-point glass powder melts and separates from the secondary film-forming particles to flow, resulting in an increase in cracks at the edges. Example 7 uses low-melting-point glass powder with larger particle sizes, and the low-melting-point glass powder melts and separates from the secondary film-forming particles to flow, resulting in an increase in cracks at the edges.

[0057] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high temperature resistant and low toxicity spray paint, characterized in that: The invention comprises a feed liquid and dimethyl ether, wherein the feed liquid comprises the following components: by weight, 20-30 parts of methyl silicone resin, 5-15 parts of high temperature resistant pigment, 15-30 parts of secondary film-forming particles, 0.1-0.2 parts of leveling agent, 0.06-0.1 parts of dispersant, 0.5-2.5 parts of anti-settling agent and 40-60 parts of diluent, wherein the secondary film-forming particles comprise phenyl silicone resin and low melting point glass powder dispersed and fixed on the phenyl silicone resin, and the size of the secondary film-forming particles is 20-50 μm, the preparation method of the secondary film-forming particles comprises: mixing the phenyl silicone resin and the low-melting point glass powder in a mixer, and then extruding at 90-100°C, crushing and sieving to obtain the secondary film-forming particles, the melting point of the low-melting point glass powder is 350-400°C, the thermal decomposition temperature of the phenyl silicone resin is ≥320°C, the mass ratio of the phenyl silicone resin to the low-melting point glass powder is 1: (1-1.5), and the brand of the phenyl silicone resin is Sihai brand 9611.

2. The high temperature resistant and low toxicity spray paint according to claim 1, characterized in that: The average particle size of the low-melting-point glass powder is 1-1.5 μm.

3. The high temperature resistant and low toxicity spray paint according to claim 1, characterized in that: The raw materials of the low-melting-point glass powder include silicon dioxide, phosphorus pentoxide and boron trioxide.

4. The high temperature resistant and low toxicity spray paint according to claim 1, characterized in that: The diluent comprises acetone.

5. The method for preparing the high temperature resistant and low toxicity spray paint according to any one of claims 1 to 4, characterized in that: The following steps are included: Weigh the phenyl silicone resin and the low-melting-point glass powder, mix them in a mixer, extrude them at 90-100° C., and then crush and sieve them to obtain the secondary film-forming particles. The methyl silicone resin, high temperature resistant pigment, secondary film-forming particles, leveling agent, dispersant, anti-settling agent and diluent are weighed according to the components, the methyl silicone resin is placed in a blender and stirred evenly, then the secondary film-forming particles are added and stirred evenly, and then the other components of the feed liquid are added and stirred evenly, and then filtered to obtain the feed liquid, the feed liquid is filled into an aerosol can with glass beads placed in it, and then the aerosol can is sealed. After the sealing is completed, the dimethyl ether is filled into the aerosol can by a pressure filling method.

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