High-temperature resistant erasable outdoor three-proof paint and its preparation method and erasure method

Abstract

The present application provides a high-temperature resistant erasable outdoor three-proof paint, a preparation method thereof, and an erasing method thereof. The three-proof paint includes a solvent, methyl silicone oil, hydrogen-containing silicone oil, a catalyst, a styrene-isoprene block copolymer, a styrene-butadiene block copolymer, and a styrene-ethylene-butene-styrene block copolymer; the mass of the styrene-isoprene block copolymer is 1%-15% of the total mass of the three-proof paint, the mass of the styrene-butadiene block copolymer is 1%-15% of the total mass of the three-proof paint, and the mass of the styrene-ethylene-butene-styrene block copolymer is 1%-5% of the total mass of the three-proof paint. The present application can effectively prevent moisture, salt spray, and chemical corrosion, has a fast curing speed, and can also maintain its performance in a high-temperature environment, and is applicable to the surfaces of components with high requirements for high-temperature resistance, hydrophobicity, and three-proof. The present application uses a supporting erasing solvent to erase the cured film formed by the three-proof paint, and has a good removal effect without residue, and is particularly applicable to precision devices such as electronic circuits.

Description

Technical Field

[0001] The present application relates to the technical field of coatings, and particularly to a high-temperature resistant erasable outdoor three-proof paint and its preparation method and erasing method. Background Art

[0002] Three-proof paint is a special paint designed for electronic circuit boards. After curing, it can form a protective film with excellent properties such as moisture-proof, dust-proof, and corrosion-proof, and can be widely used in civil, automotive, aerospace, and marine fields to improve the reliability and service life of electronic devices.

[0003] In the existing three-proof paint technology, a significant problem is that in a high-temperature environment, the resin molecular structure in the three-proof paint is easily damaged, resulting in the cured film losing its original hardness and toughness, thereby affecting its protection effect. This limits the application of existing three-proof paints in high-temperature environments and cannot meet the requirements for high-temperature stability in some specific fields.

[0004] The second problem existing in the prior art is the slow curing speed. The curing process of traditional three-proof paints often requires a long time, which not only affects production efficiency but also may cause the coating to be contaminated or damaged during the curing process. Especially in some occasions where rapid production is required, the slow curing speed has become a key factor restricting the application of three-proof paints.

[0005] Current three-proof paints are usually used on precision circuit boards such as 5G single boards and drone single boards. If such circuit boards fail at the customer site, they usually need to be returned to the original factory for repair. On the one hand, the cost of returning to the original factory is relatively high. On the other hand, even if returned to the original factory, successful repair is not guaranteed. Therefore, equipment operators require equipment manufacturers to be able to achieve the function of on-site repairability while ensuring high reliability, which can improve the reuse rate of single boards and reduce operating costs.

[0006] In response to this situation, the third problem existing in the prior art is that when repairing precision circuit boards, it is necessary to remove the three-proof cured film layer on their surfaces. However, the customer site does not have precision paint removal equipment, making it difficult to remove the three-proof paint on precision circuit boards. Traditional methods for removing three-proof paint, such as knife cutting, scraping, dry ice cleaning, steel brushing, and brushing with a brush, are inefficient and cannot be applied to precision circuit boards, which may cause irreversible damage to electronic components. Using general chemical solvents to remove three-proof paint often results in incomplete removal, making it possible that the new coating may not adhere effectively, is prone to peeling or stripping, and at the same time, the residue of chemical solvents may also pose hazards to the coated products and the environment.

[0007] It should be noted that this part of the content of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or well-known technology. Summary of the Invention

[0008] In view of this, the purpose of the present application is to provide a high-temperature resistant erasable outdoor three-proof paint, its preparation method and erasing method, so as to at least simultaneously solve the problems of slow curing speed, poor high-temperature resistance and difficulty in repair in the prior art. The present application can effectively prevent moisture, salt spray and chemical corrosion, has a fast curing speed, and can also maintain its performance in a high-temperature environment, and is applicable to the surfaces of components with high requirements for high-temperature resistance, hydrophobicity and three-proof. At the same time, the present application uses a supporting erasing solvent to erase the cured film formed by the three-proof paint, and the removal effect is good without residue, especially applicable to precision devices such as electronic circuits.

[0009] In the first aspect, the present application provides a high-temperature resistant erasable outdoor three-proof paint, which includes a solvent, methyl silicone oil, hydrogen-containing silicone oil, a catalyst, styrene-isoprene block copolymer, styrene-butadiene block copolymer, styrene-ethylene-butene-styrene block copolymer; the mass of the styrene-isoprene block copolymer is 1%-15% of the total mass of the three-proof paint, the mass of the styrene-butadiene block copolymer is 1%-15% of the total mass of the three-proof paint, and the mass of the styrene-ethylene-butene-styrene block copolymer is 1%-5% of the total mass of the three-proof paint.

[0010] In some embodiments, the mass ratio among the styrene-isoprene block copolymer, the styrene-butadiene block copolymer and the styrene-ethylene-butene-styrene block copolymer is 1-10:1-10:1-3.

[0011] In some embodiments, the number-average molecular weight of the styrene-isoprene block copolymer is 50,000-150,000, the number-average molecular weight of the styrene-butadiene block copolymer is 55,000-150,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 70,000-220,000.

[0012] In some embodiments, the solvent is composed of at least one of petroleum ether, isooctane, isoheptane, and isohexane, and the mass of the solvent is 40%-80% of the total mass of the three-proof paint.

[0013] In some embodiments, the solvent is composed of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 5-7:3-5.

[0014] In some embodiments, the mass of the methyl silicone oil is 3%-15% of the total mass of the three-proof paint, the viscosity range of the methyl silicone oil is 10,000-30,000 mPa·s, and the volatile content is less than 1%.

[0015] In some embodiments, the mass of the hydrogen-containing silicone oil is 0.5%-5% of the total mass of the three-proof paint, the viscosity range of the hydrogen-containing silicone oil is 3000-10,000 mPa·s, and the volatile content is less than 1%.

[0016] In some embodiments, the three-proof paint further includes calcium carbonate, stearic acid, and UV pigment. The mass of calcium carbonate is 0.5%-3% of the total mass of the three-proof paint, the mass of stearic acid is 0.5%-3% of the total mass of the three-proof paint, and the mass of UV pigment is 0.1%-0.5% of the total mass of the three-proof paint;

[0017] In some embodiments, the catalyst is a Kast catalyst, and the mass of the Kast catalyst is 0.1%-0.5% of the total mass of the three-proof paint;

[0018] In some embodiments, the three-proof paint further includes water, and the mass of water is 0.5%-2% of the total mass of the three-proof paint.

[0019] In a second aspect, the present application also provides a method for preparing a high-temperature resistant and erasable outdoor three-proof paint. The preparation method is used to prepare a high-temperature resistant and erasable outdoor three-proof paint, including the following steps:

[0020] S1. Weigh each component according to the ratio;

[0021] S2. Add methyl silicone oil to the solvent and stir and disperse for 1-2 h;

[0022] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 85-95 °C and stir and disperse for 4-6 h;

[0023] S4. Cool to room temperature;

[0024] S5. After adding hydrogen-containing silicone oil and catalyst, stir at room temperature overnight to obtain the final product.

[0025] In some embodiments, in S2, before adding methyl silicone oil to the solvent, it further includes mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heating to 85-95 °C, dispersing for 1-2 h, and cooling to room temperature.

[0026] In some embodiments, in S5, the catalyst is a Kast catalyst;

[0027] In some embodiments, in S5, water is added dropwise within 1-2 h of stirring at room temperature.

[0028] In a third aspect, the present application also provides a method for erasing the cured film formed by the high-temperature resistant and erasable outdoor three-proof paint. The cured film formed by the three-proof paint is erased by using a supporting erasing solvent, wherein the supporting erasing solvent includes n-octane and petroleum ether.

[0029] The beneficial effects that the present application can achieve are:

[0030] 1. This product has a low viscosity at room temperature and is suitable for a variety of coating preparation processes including spraying, brushing, pouring, dipping, and dispensing machines. At the same time, low viscosity helps to evenly coat the surface of electronic components, reducing uneven coating and dripping, helping the three-proof paint to better penetrate into the gaps and corners of electronic components, providing more comprehensive protection, and helping to reduce bubbles and pinholes in the coating, thereby improving the uniformity and protective performance of the coating;

[0031] 2. This product is a one-component reactive conformal coating product. Compared with two-component conformal coating products, it does not require the addition of curing agent in proportion during the coating preparation process, which reduces the complexity of construction and allows immediate use after application.

[0032] 3. This product can be cured at room temperature or by heating. It has a fast curing speed. At room temperature, it can be cured within 5 minutes, which is suitable for the process requirements of automated production lines.

[0033] 4. It has good high temperature resistance. On the basis of maintaining good three-proof performance, it can work at 200℃ for a long time and can instantly withstand up to 300℃, which can provide reliable protection for electronic circuit boards under extreme temperature conditions;

[0034] 5. The conformal coating product prepared by this product does not contain fluorine or other permanent compounds, meets multiple technical indicators including the IPC-CC-830 standard, and has more advantages in environmental protection;

[0035] 6. This application uses a matching erasing solvent to erase the cured film formed by the three-proof paint, which has a good removal effect and no residue, and is especially suitable for precision devices such as electronic circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A physical picture of the IPC standard sample after being irradiated with 365nm UVA ultraviolet rays and coated with the triple-proof paint of Example 1 of the present application is shown;

[0038] Figure 2 The actual picture of the IPC standard sample before the salt spray test after the triple-proof coating of Example 1 of the present application is applied is shown;

[0039] Figure 3 The actual picture of the IPC standard sample after the salt spray test after the triple-proof paint of Example 1 of the present application is applied is shown;

[0040] Figure 4 A physical picture of the IPC standard sample before the salt spray test without the conformal coating of Example 1 of the present application is shown;

[0041] Figure 5 A physical picture of the IPC standard sample after the salt spray test without the conformal coating of Example 1 of the present application is shown;

[0042] Figure 6 A physical picture of the waterproof test of the IPC standard sample after a portion of the present application is coated with the triple-proof paint of Example 1 is shown;

[0043] Figure 7 The thermal analysis curve of the three-proof paint obtained in Example 1 of the present application is shown. DETAILED DESCRIPTION

[0044] The term "comprising" in the specification and claims of the present application and the drawings is synonymous with "including", "containing" or "characterized by", and is inclusive or open-ended, and does not exclude additional undescribed elements or method steps. "Comprising" is a technical term used in the claim language, meaning that the elements are present, but other elements may also be added and still form a structure or method within the scope of the claim.

[0045] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. The term "about" in this application means to include a small change (up to + / -10%) from the stated value.

[0046] In the first aspect, the present application provides a high-temperature resistant and erasable outdoor conformal paint, which includes a solvent, methyl silicone oil, hydrogenated silicone oil, a catalyst, a styrene-isoprene block copolymer, a styrene-butadiene block copolymer, and a styrene-ethylene-butylene-styrene block copolymer; the mass of the styrene-isoprene block copolymer is 1%-15% of the total mass of the conformal paint, the mass of the styrene-butadiene block copolymer is 1%-15% of the total mass of the conformal paint, and the mass of the styrene-ethylene-butylene-styrene block copolymer is 1%-5% of the total mass of the conformal paint.

[0047] Styrene-isoprene block copolymer (SIS) is a synthetic polymer material composed of styrene and isoprene monomers arranged alternately in a block structure. It has good elasticity and resilience and can return to its original shape after strain. SIS exhibits high viscosity and can provide good adhesion properties. At low temperatures, SIS can still maintain good elasticity and viscosity. It has good tolerance to some common solvents and chemicals.

[0048] Styrene-butadiene block copolymer (SBS) is a triblock copolymer with styrene and butadiene as monomers, known as the "third generation of synthetic rubber". SBS has the properties of plastic and rubber, with excellent tensile strength, large surface friction coefficient, good low temperature performance, excellent electrical properties, and good processing performance.

[0049] Styrene-ethylene-butylene-styrene block copolymer (SEBS) is a block copolymer of styrene (S)-ethylene (E) / butylene (B)-(S), which combines the thermoplastic characteristics of polystyrene and the elastomeric characteristics of ethylene-butylene copolymer in the same polymer. SEBS does not contain unsaturated double bonds, so it has good stability and aging resistance. SEBS has good UV stability, oxidation resistance and thermal stability.

[0050] It should be noted that the mass of the styrene-isoprene block copolymer is 1%-15% of the total mass of the conformal coating, and can be 1%, 3%, 5%, 8%, 10%, 12%, 15% and any value therebetween. Preferably, the mass of the styrene-isoprene block copolymer is 4% of the total mass of the conformal coating.

[0051] The mass of the styrene-butadiene block copolymer is 1%-15% of the total mass of the conformal coating, and can be 1%, 3%, 5%, 8%, 10%, 12%, 15% and any value therebetween. Preferably, the mass of the styrene-butadiene block copolymer is 4% of the total mass of the conformal coating.

[0052] The mass of the styrene-ethylene-butylene-styrene block copolymer is 1%-5% of the total mass of the conformal coating, and can be 1%, 2%, 3%, 4%, 5% and any value therebetween. Preferably, the mass of the styrene-ethylene-butylene-styrene block copolymer is 3% of the total mass of the conformal coating.

[0053] Adding a combination of three specific block copolymers in a preferred ratio is more conducive to improving the rapid curing performance and thermal stability of the final three-proof coating product.

[0054] The applicant of the present application has creatively discovered a three-proof paint system consisting of methyl silicone oil + hydrogen-containing silicone oil + a combination of three specific block copolymers + solvent + catalyst. By adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer in specific proportions, the combination of the three block copolymers synergizes with the other components, and finally a three-proof paint product can be obtained that can complete curing within 5 minutes at room temperature and has excellent high-temperature resistance. At the same time, it can also effectively prevent moisture, salt spray, and chemical corrosion, and has excellent three-proof performance.

[0055] Although the mechanism is not yet clear, experiments have proved that the core components of the three-proof paint made of silicone oil + hydrogen-containing silicone oil + a combination of three block copolymers + solvent + catalyst are beneficial to significantly improve the curing performance and high-temperature resistance of the three-proof paint. The possible reasons are speculated as follows:

[0056] The structures of the specifically designed styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer can adjust the molecular weight distribution and intermolecular forces of the polymer, thereby affecting its viscosity and curing behavior.

[0057] The introduction of styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer can change the fluidity and molecular weight of the three-proof paint, thereby reducing the viscosity of the system. Specifically, the different monomer units in the copolymer can provide different functional groups and segments, and the introduction of these segments helps to break the entanglement between polymer chains and reduce the intermolecular forces, thereby reducing the viscosity of the overall system.

[0058] The addition of styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer can provide additional reactive sites to promote the curing reaction. The segments of the copolymer in the present application can react with silicone, increasing the curing speed. This synergistic effect helps the three-proof paint to achieve complete curing at room temperature without the need for additional heating or adding driers.

[0059] The introduction of styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer can improve the compatibility between the components in the silicone system, which is beneficial for reducing viscosity and increasing the curing speed. Good compatibility can ensure the uniformity and stability of the cured film, thereby improving the curing efficiency.

[0060] During the curing process of conformal coating, the steric hindrance effect caused by the increase in molecular weight will increase, which will slow down the reaction rate. By adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, styrene-ethylene-butylene-styrene block copolymer, the molecular structure and intermolecular forces of the polymer can be effectively adjusted, the flexibility of the chain segments can be improved and the distance between molecules can be increased, thereby reducing the steric hindrance effect, making it easier for the reactive groups to contact and react, thereby accelerating the curing speed.

[0061] The present application can introduce more specific segments through the molecular structures of specifically designed styrene-isoprene block copolymers, styrene-butadiene block copolymers, and styrene-ethylene-butylene-styrene block copolymers, which have high thermal stability, thereby improving the temperature resistance of the three-proof paint. At the same time, by increasing the cross-linking density of the copolymer in the three-proof paint, its thermal stability and mechanical strength can be improved, thereby improving the temperature resistance.

[0062] The specific ratios of styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butylene-styrene block copolymer in this application improve the physical and chemical properties of the three-proof paint, making the three-proof paint easier to erase after curing, which is very important for the maintenance and rework process of electronic equipment. More specifically, the addition of three specific ratios of copolymers improves the compatibility of the components of the three-proof paint, reduces the porosity of the cured film, reduces the volume shrinkage of the cured film, and increases the flexibility of the cured film. The combined effect of these characteristics makes the cured film easier to be removed as a whole. Furthermore, the addition of three specific ratios of copolymers also improves the cross-linking properties of the three-proof paint, so that it can be erased by the matching erasing solvent of this application, with good removal effect and no residue, and is particularly suitable for precision electronic circuit devices.

[0063] In some embodiments, the mass ratio of styrene-isoprene block copolymer, styrene-butadiene block copolymer and styrene-ethylene-butylene-styrene block copolymer is 1-10:1-10:1-3. Among them, the preferred mass ratio of the three is 4:4:3, but it is not limited to this. Reasonable setting of the mass ratio between styrene-isoprene block copolymer, styrene-butadiene block copolymer and styrene-ethylene-butylene-styrene block copolymer is conducive to improving the rapid curing performance and thermal stability of the final three-proof paint product. At the same time, the reasonable allocation of the three can affect the density of the cured film, thereby affecting the corrosion resistance.

[0064] In some embodiments, the number average molecular weight of the styrene-isoprene block copolymer is 50,000-150,000, which can be 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, and any value therebetween; the number average molecular weight of the styrene-butadiene block copolymer is 55,000-150,000, which can be 55,000, 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, and any value therebetween; the number average molecular weight of the styrene-ethylene-butylene-styrene block copolymer is 70,000-220,000, which can be 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 210,000, 220,000, and any value therebetween.

[0065] Preferably, the number average molecular weight of the styrene-isoprene block copolymer is 70,000, the number average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number average molecular weight of the styrene-ethylene-butylene-styrene block copolymer is 120,000. Reasonable setting of the number average molecular weights of the styrene-isoprene block copolymer, the styrene-butadiene block copolymer and the styrene-ethylene-butylene-styrene block copolymer can adjust the film-forming speed and coating density of the cured film, and can also improve the corrosion resistance and weather resistance of the cured film.

[0066] In some embodiments, the solvent is composed of at least one of petroleum ether, isooctane, isoheptane, and isohexane. The present application has no special requirements for the properties of the specific components as long as they can be used to dissolve polymers.

[0067] In some embodiments, the mass of the solvent is 40%-80% of the total mass of the conformal coating, and can be 40%, 50%, 60%, 70%, 80% and any value therebetween; reasonably setting the mass of the solvent can accelerate the dissolution rate of the polymer and increase production efficiency.

[0068] It should be noted that the solvent is preferably composed of isooctane and petroleum ether. The advantage of using isooctane and petroleum ether is that the storage stability of the conformal coating product can be improved.

[0069] In some embodiments, the mixing ratio of isooctane and petroleum ether is 5-7:3-5, and the mixing ratio of isooctane and petroleum ether is preferably 7:3, but is not limited thereto, and can be 5:5, 5.5:4.5, 6:4, 6.5:3.5, and any value therebetween. The advantage of setting a reasonable mixing ratio of isooctane and petroleum ether is that the storage stability of the conformal coating product can be improved.

[0070] In some embodiments, the mass of the methyl silicone oil is 3%-15% of the total mass of the conformal coating, and can be 3%, 5%, 8%, 10%, 12%, 15% and any value therebetween; the viscosity of the methyl silicone oil is in the range of 10,000-30,000 mPas, and the volatile matter is less than 1%. Reasonable selection of the mass and properties of the methyl silicone oil can further improve the heat resistance of the coating.

[0071] In some embodiments, the mass of hydrogen-containing silicone oil is 0.5%-5% of the total mass of the conformal coating, and can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% and any value therebetween; the viscosity of hydrogen-containing silicone oil ranges from 3000 to 10,000 mPas, and the volatile matter is less than 1%. Reasonable selection of the mass and properties of hydrogen-containing silicone oil can further improve the curing speed of the coating.

[0072] In some embodiments, the conformal coating further comprises calcium carbonate, stearic acid, and UV pigment, wherein the mass of calcium carbonate is 0.5%-3% of the total mass of the conformal coating, and may be 0.5%, 1%, 1.5%, 2%, 2.5%, 3% and any value therebetween; the mass of stearic acid is 0.5%-3% of the total mass of the conformal coating, and may be 0.5%, 1%, 1.5%, 2%, 2.5%, 3% and any value therebetween; the mass of UV pigment is 0.1%-0.5% of the total mass of the conformal coating, and may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and any value therebetween; the purpose of adding calcium carbonate and stearic acid is to increase the wear resistance of the coating, and the purpose of adding UV pigment is to facilitate the quality inspection of the coating under ultraviolet conditions.

[0073] In some embodiments, the catalyst is a Custer catalyst, and the mass of the Custer catalyst is 0.1%-0.5% of the total mass of the conformal coating, and can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and any value therebetween;

[0074] It should be noted that the Custer catalyst is a preferred choice, but is not limited thereto. The present application does not particularly limit the catalyst used, and it can be a catalyst conventionally used in a three-proof paint known to those skilled in the art. Preferably, the catalyst can also be a platinum catalyst or an organic catalyst. Adding a catalyst to the three-proof paint can further accelerate the curing speed of the coating.

[0075] In some embodiments, the conformal coating further comprises water, and the mass of the water is 0.5%-2% of the total mass of the conformal coating, and can be 0.5%, 1%, 1.5%, 2% and any value therebetween. Adding water to the conformal coating can further increase the storage period of the conformal coating product.

[0076] It is understandable that calcium carbonate, stearic acid, UV pigment and water are used to optimize the storage performance, detection method or performance of the conformal coating. Even if these components are not added, it does not affect the preparation of the high temperature resistant and erasable outdoor conformal coating of the technical solution of this application by other components.

[0077] In a second aspect, the present application also provides a method for preparing a high temperature resistant and erasable outdoor conformal coating, the method for preparing a high temperature resistant and erasable outdoor conformal coating comprises the following steps:

[0078] S1. Weigh each component according to the proportion;

[0079] S2. Add methyl silicone oil to the solvent and stir and disperse for 1-2h;

[0080] S3, after adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, styrene-ethylene-butylene-styrene block copolymer, heating to 85-95°C and stirring and dispersing for 4-6h;

[0081] S4, cooling to room temperature;

[0082] S5. After adding hydrogen-containing silicone oil and a catalyst, stirring was continued at room temperature overnight to obtain the final product.

[0083] The present application has no particular restrictions on the methods of stirring and dispersing and stirring at room temperature, and a suitable stirring speed can be selected according to the specific situation.

[0084] In some embodiments, before adding methyl silicone oil to the solvent in S2, the solvent is mixed with calcium carbonate, stearic acid, and UV pigment, heated to 85-95° C. for dispersion for 1-2 hours, and cooled to room temperature. The purpose of this step is to allow calcium carbonate, stearic acid, and UV pigment functional additives to be fully mixed and dispersed with the coating matrix.

[0085] In some embodiments, in S5, the catalyst is a Custer catalyst;

[0086] In some embodiments, in S5, water is added dropwise within 1-2 hours of stirring at room temperature. The purpose of this step is to further increase the storage period of the product.

[0087] The order of adding materials designed by the present application can improve production efficiency and reduce production costs.

[0088] In a third aspect, the present application also provides a method for erasing a cured film formed by a heat-resistant erasable outdoor three-proof paint. The cured film formed by the three-proof paint is erased using a supporting erasing solvent, where the supporting erasing solvent includes n-octane and petroleum ether. The supporting erasing solvent of the present application can remove the three-proof paint more quickly, leaving no residue after erasing, which can effectively improve the cleaning efficiency. Especially when large-scale cleaning or repair is required, this method can save time and cost; the removal effect is good without residue, and it is especially suitable for precision devices such as electronic circuits.

[0089] Next, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0090] As used herein, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0091] The following three-proof paints in Examples 1-12 and Comparative Examples 1-5 will be prepared according to the formulations listed in Table 1.

[0092] Table 1

[0093]

[0094] The manufacturers and purities of the component reagents used in the embodiments and comparative examples of the present application are as follows. It should be noted that the following content does not limit the scope of protection of the present application, but is only an illustrative description:

[0095] The solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3. Among them, isooctane and petroleum ether (Guoyao Reagent Chemical Co., Ltd., analytical pure);

[0096] Calcium carbonate (Guoyao Reagent Chemical Co., Ltd., chemically pure);

[0097] Stearic acid (Guoyao Reagent Chemical Co., Ltd., chemically pure);

[0098] UV pigment (Shanghai Jingyan Chemical Co., Ltd., industrial grade);

[0099] Methyl silicone oil (Zhonghao Chenguang Research Institute of Chemical Industry Co., Ltd., chemically pure);

[0100] Styrene-isoprene block copolymer (Zhonghao Chenguang Research Institute of Chemical Industry Co., Ltd., industrial grade);

[0101] Styrene-butadiene block copolymer (Zhonghao Chenguang Research Institute of Chemical Industry Co., Ltd., industrial grade);

[0102] Styrene-ethylene-butene-styrene block copolymer (Zhonghao Chenguang Research Institute of Chemical Industry Co., Ltd., industrial grade);

[0103] Hydrogen-containing silicone oil (Zhonghao Chenguang Research Institute of Chemical Industry Co., Ltd., industrial grade);

[0104] The catalyst is Karstedt catalyst, among which, Karstedt catalyst (Guangzhou Xiupu Chemical Co., Ltd., industrial grade);

[0105] Water (Guoyao Reagent Chemical Co., Ltd., purified water).

[0106] Example 1

[0107] A high-temperature resistant erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 68.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 4% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0108] The preparation method of the above three-proof paint includes the following specific steps:

[0109] S1. Weigh each component according to the ratio;

[0110] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95°C and disperse for 1 h, then cool it to room temperature, and then add methyl silicone oil and stir and disperse for 1 h;

[0111] Among them, the solvent is composed of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0112] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0113] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat it to 95°C and stir and disperse for 6 h;

[0114] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0115] S4. Cool to room temperature;

[0116] S5. After adding the hydrogen-containing silicone oil and the Karstedt catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0117] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0118] Example 2

[0119] A three-proof paint for high-temperature resistant and erasable outdoor use, based on the total mass of the three-proof paint being 100%, includes 71.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 1% of styrene-isoprene block copolymer, 4% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0120] The preparation method of the above three-proof paint includes the following specific steps:

[0121] S1. Weigh each component according to the ratio;

[0122] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95 °C and disperse for 1 h, then cool to room temperature, and then add methyl silicone oil and stir for 1 h;

[0123] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0124] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0125] S3. After adding the styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95 °C and stir for 6 h;

[0126] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0127] S4. Cool to room temperature;

[0128] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature and add water dropwise within 2 hours of stirring at room temperature to obtain the final product.

[0129] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0130] Example 3

[0131] A heat-resistant erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 64.4% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 8% styrene-isoprene block copolymer, 4% styrene-butadiene block copolymer, 3% styrene-ethylene-butene-styrene block copolymer, 2% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0132] The preparation method of the above three-proof paint includes the following specific steps:

[0133] S1. Weigh each component according to the ratio.

[0134] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95°C and disperse for 1 hour, then cool to room temperature, and then add methyl silicone oil and stir and disperse for 1 hour.

[0135] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3.

[0136] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0137] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95°C and stir and disperse for 6 hours.

[0138] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0139] S4. Cool to room temperature.

[0140] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature and add water dropwise within 2 hours of stirring at room temperature to obtain the final product.

[0141] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0142] Example 4

[0143] A heat-resistant erasable outdoor three-proof paint, based on the total mass of the three-proof paint being 100%, includes 57.4% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 15% styrene-isoprene block copolymer, 4% styrene-butadiene block copolymer, 3% styrene-ethylene-butene-styrene block copolymer, 2% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0144] The preparation method of the above three-proof paint includes the following specific steps:

[0145] S1. Weigh each component according to the ratio.

[0146] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95°C and disperse for 1 h, then cool to room temperature, and then add methyl silicone oil and stir to disperse for 1 h.

[0147] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3.

[0148] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0149] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95°C and stir to disperse for 6 h.

[0150] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0151] S4. Cool to room temperature.

[0152] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature, and dropwise add water within 2 h of stirring at room temperature to obtain the final product.

[0153] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0154] Example 5

[0155] A heat-resistant erasable outdoor three-proof paint, based on the total mass of the three-proof paint being 100%, includes 71.4% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 4% styrene-isoprene block copolymer, 1% styrene-butadiene block copolymer, 3% styrene-ethylene-butene-styrene block copolymer, 2% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0156] The preparation method of the above three-proof paint comprises the following specific steps:

[0157] S1. Weigh each component according to the ratio;

[0158] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95 °C, disperse for 1 h, and cool to room temperature. Then add methyl silicone oil and stir and disperse for 1 h;

[0159] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0160] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0161] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat it to 95 °C and stir and disperse for 6 h;

[0162] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0163] S4. Cool to room temperature;

[0164] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir at room temperature overnight, and dropwise add water within 2 h of stirring at room temperature to obtain the final product.

[0165] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0166] Example 6

[0167] A high-temperature resistant and erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 64.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 8% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0168] The preparation method of the above three-proof paint comprises the following specific steps:

[0169] S1. Weigh each component according to the ratio;

[0170] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95 °C, disperse for 1 h, and cool to room temperature. Then add methyl silicone oil and stir and disperse for 1 h;

[0171] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0172] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0173] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95°C and stir for dispersion for 6 h;

[0174] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0175] S4. Cool to room temperature;

[0176] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir at room temperature overnight, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0177] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0178] Example 7

[0179] A heat-resistant erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 57.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 15% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0180] The preparation method of the above three-proof paint includes the following specific steps:

[0181] S1. Weigh each component according to the ratio;

[0182] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95°C for dispersion for 1 h and cool to room temperature, then add methyl silicone oil and stir for dispersion for 1 h;

[0183] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0184] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0185] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95°C and stir for dispersion for 6 h;

[0186] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0187] S4. Cool to room temperature;

[0188] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0189] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0190] Example 8

[0191] A heat-resistant erasable outdoor three-proof paint, based on 100% of the total mass of the three-proof paint, includes 70.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 4% of styrene-butadiene block copolymer, 1% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0192] The preparation method of the above three-proof paint includes the following specific steps:

[0193] S1. Weigh each component according to the ratio;

[0194] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95°C for dispersion for 1 h and cool to room temperature, then add methyl silicone oil and stir for dispersion for 1 h;

[0195] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0196] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0197] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95°C and stir for dispersion for 6 h;

[0198] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0199] S4. Cool to room temperature;

[0200] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0201] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0202] Example 9

[0203] A heat-resistant erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 66.4% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 4% styrene-isoprene block copolymer, 4% styrene-butadiene block copolymer, 5% styrene-ethylene-butene-styrene block copolymer, 2% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0204] The preparation method of the above three-proof paint includes the following specific steps:

[0205] S1. Weigh each component according to the ratio;

[0206] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat to 95 °C and disperse for 1 h, then cool to room temperature, and then add methyl silicone oil and stir and disperse for 1 h;

[0207] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0208] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0209] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 95 °C and stir and disperse for 6 h;

[0210] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0211] S4. Cool to room temperature;

[0212] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0213] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile matter is less than 0.6%.

[0214] Example 10

[0215] A heat-resistant erasable outdoor three-proof paint. Based on the total mass of the three-proof paint being 100%, it includes 68.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 4% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0216] The preparation method of the above three-proof paint includes the following specific steps:

[0217] S1. Weigh each component according to the ratio.

[0218] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95°C and disperse for 1 h, then cool it to room temperature, and then add methyl silicone oil and stir and disperse for 1 h.

[0219] Among them, the solvent is composed of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3.

[0220] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0221] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat it to 95°C and stir and disperse for 6 h.

[0222] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 120,000, the number-average molecular weight of the styrene-butadiene block copolymer is 120,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 200,000.

[0223] S4. Cool it to room temperature.

[0224] S5. After adding hydrogen-containing silicone oil and Kaster catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0225] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0226] Example 11

[0227] A heat-resistant erasable outdoor three-proof paint, calculated based on the total mass of the three-proof paint being 100%, includes 69.9% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 4% styrene-isoprene block copolymer, 4% styrene-butadiene block copolymer, 3% styrene-ethylene-butene-styrene block copolymer, 0.5% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0228] The preparation method of the above three-proof paint includes the following specific steps:

[0229] S1. Weigh each component according to the ratio;

[0230] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95°C and disperse for 1 h, then cool it to room temperature, and then add methyl silicone oil and stir and disperse for 1 h;

[0231] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3;

[0232] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0233] S3. After adding the styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat it to 95°C and stir and disperse for 6 h;

[0234] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0235] S4. Cool to room temperature;

[0236] S5. After adding the hydrogen-containing silicone oil and Kaster catalyst, stir at room temperature overnight, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0237] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0238] Example 12

[0239] A heat-resistant erasable outdoor three-proof paint, calculated based on the total mass of the three-proof paint being 100%, includes 65.4% solvent, 0.5% calcium carbonate, 0.5% stearic acid, 0.1% UV pigment, 15% methyl silicone oil, 4% styrene-isoprene block copolymer, 4% styrene-butadiene block copolymer, 3% styrene-ethylene-butene-styrene block copolymer, 5% hydrogen-containing silicone oil, 0.5% catalyst, and 2% water.

[0240] The preparation method of the above three-proof paint includes the following specific steps:

[0241] S1. Weigh each component according to the ratio.

[0242] S2. After mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heat it to 95 °C for 1 h of dispersion and then cool it to room temperature. Then add methyl silicone oil and stir for 1 h of dispersion.

[0243] Among them, the solvent consists of isooctane and petroleum ether, and the mixing ratio of isooctane and petroleum ether is 7:3.

[0244] The viscosity range of the methyl silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0245] S3. After adding styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat it to 95 °C and stir for 6 h of dispersion.

[0246] Among them, the number-average molecular weight of the styrene-isoprene block copolymer is 70,000, the number-average molecular weight of the styrene-butadiene block copolymer is 80,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 120,000.

[0247] S4. Cool it to room temperature.

[0248] S5. After adding hydrogen-containing silicone oil and Karstedt catalyst, stir overnight at room temperature, and add water dropwise within 2 h of stirring at room temperature to obtain the final product.

[0249] Among them, the viscosity range of the hydrogen-containing silicone oil is 10,000 mPa·s, and the volatile content is less than 0.6%.

[0250] Comparative Example 1

[0251] A three-proof paint, based on the total mass of the three-proof paint being 100%, includes 72.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-butadiene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0252] The preparation method refers to the preparation method in Example 1. The difference is that in Comparative Example 1, the styrene-isoprene block copolymer is not added, and the missing mass is made up by the solvent.

[0253] Comparative Example 2

[0254] A three-proof paint, based on the total mass of the three-proof paint being 100%, includes 72.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 3% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0255] The preparation method refers to the preparation method in Example 1, with the difference that: in Comparative Example 2, styrene-butadiene block copolymer was not added, and the missing mass was made up by the solvent.

[0256] Comparative Example 3

[0257] A three-proof paint, based on the total mass of the three-proof paint being 100%, includes 71.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 4% of styrene-isoprene block copolymer, 4% of styrene-butadiene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0258] The preparation method refers to the preparation method in Example 1, with the difference that: in Comparative Example 3, styrene-ethylene-butene-styrene block copolymer was not added, and the missing mass was made up by the solvent.

[0259] Comparative Example 4

[0260] A three-proof paint, based on the total mass of the three-proof paint being 100%, includes 19.4% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 20% of styrene-isoprene block copolymer, 20% of styrene-butadiene block copolymer, 20% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0261] The preparation method refers to the preparation method in Example 1.

[0262] Comparative Example 5

[0263] A three-proof paint, based on the total mass of the three-proof paint being 100%, includes 77.9% of solvent, 0.5% of calcium carbonate, 0.5% of stearic acid, 0.1% of UV pigment, 15% of methyl silicone oil, 0.5% of styrene-isoprene block copolymer, 0.5% of styrene-butadiene block copolymer, 0.5% of styrene-ethylene-butene-styrene block copolymer, 2% of hydrogen-containing silicone oil, 0.5% of catalyst, and 2% of water.

[0264] The preparation method refers to the preparation method in Example 1.

[0265] Test Example

[0266] In order to verify the performance of the product of the present application, the three-proof coatings prepared in Examples 1-12 and Comparative Examples 1-5 were respectively subjected to relevant performance tests. The specific test results are shown in Tables 2 and 3. The specific test methods in Tables 2 and 3 are as follows:

[0267] Viscosity: coating-4 cup method, test temperature 25℃, relative humidity 55%;

[0268] Complete curing time: The test temperature is 25℃ and the relative humidity is 55%. Spray the conformal coating on the glass test piece and start timing immediately. The timing ends when the conformal coating changes from transparent to white translucent. At the same time, the glass test piece is completely immersed below the water surface. If the surface of the cured film is cured without flow, the recorded time is the complete curing time.

[0269] Working temperature: hot table 200℃ test;

[0270] Initial decomposition temperature: For detection method, refer to GB / T27761-2011;

[0271] Salt spray resistance: See GB / T1771-2007 for the test method;

[0272] Water contact angle: For the test method, refer to GB / T30693-2014;

[0273] 10h@200℃ apparent state after treatment: visual inspection, visual inspection after 365nmUVA ultraviolet irradiation;

[0274] Use n-octane and petroleum ether to erase: After 10h@200℃ treatment, erase the cured film to check whether there is any n-octane and petroleum ether residue, and check whether the circuit board is damaged.

[0275] Table 2 Uncured properties of products of Examples 1-12 and Comparative Examples 1-5

[0276]

[0277] Table 3 Performance of products of Examples 1-12 and Comparative Examples 1-5 after curing

[0278]

[0279] It can be seen from the results of Table 2 and Table 3 that, relative to the comparative example, by adopting the embodiment of the present invention, by adding a specific ratio of styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butylene-styrene block copolymer, the combination of the three block copolymers and the other ingredients work together to obtain a conformal coating product that has significantly shorter complete curing time, higher working temperature, initial decomposition temperature, better salt spray resistance and hydrophobicity.

[0280] It can also be seen that the three-proof paint in the comparative example has poor heat resistance. After being treated at 200 °C for 10 h, the appearance state of the cured film turned yellow. It is speculated that some pyrolysis reaction or oxidation reaction may have occurred, which will seriously affect the subsequent use performance. Further, based on the erasing performance of n-octane and petroleum ether, it is guessed that the crosslinking degree of the cured film during the heat treatment process has changed, resulting in the inability to completely erase the cured film formed by the three-proof paint using n-octane and petroleum ether. At the same time, it is found that there is certain damage to the circuit board after removing the cured film, proving that the three-proof paint in the comparative example cannot protect the circuit board at high temperatures.

[0281] Furthermore, the three-proof paint adopting the technical solution of the present application can still be erased by the erasing solvent provided in the present application even after high-temperature treatment, proving that the present application has excellent high-temperature resistance. At the same time, it is proved that even in a harsh use environment, the erasing method of the present application can still be used to erase it.

[0282] Furthermore, according to Examples 1-12, it can be known that by adopting the preferred scheme of the present invention, a single-component three-proof paint product with higher use temperature, faster curing speed, stronger protection ability and other characteristics can be obtained.

[0283] The technical effects of the technical solution of the present application are illustrated below through product physical pictures. After the three-proof paint obtained in Example 1 was coated on the IPC standard sample board to form a cured film, tests were carried out.

[0284] As Figure 1 shown, Figure 1 is a physical picture of the IPC standard sample board coated with the three-proof paint of Example 1 irradiated by 365 nm UVA ultraviolet rays.

[0285] As Figure 2 shown, Figure 2 is a physical picture of the IPC standard sample board coated with the three-proof paint of Example 1 before salt spray test. As Figure 3 shown, Figure 3 is a physical picture of the IPC standard sample board coated with the three-proof paint of Example 1 after salt spray test. It can be seen that the cured film formed by the three-proof paint of Example 1 of the present application has strong salt spray resistance, and the appearance has basically not changed before and after the salt spray test.

[0286] As Figure 4 shown, Figure 4 is a physical picture of the IPC standard sample board without coating the three-proof paint of Example 1 before salt spray test. As Figure 5 shown, Figure 5 is a physical picture of the IPC standard sample board without coating the three-proof paint of Example 1 after salt spray test. It can be seen that if the three-proof paint is not coated, the bare copper wire part on the IPC standard sample board is severely corroded.

[0287] like Figure 6 As shown, Figure 6 The upper part of the device is coated with the conformal coating of Example 1. Figure 6 The lower part of the glass is not coated with the conformal coating of Example 1. It can be seen that Figure 6 A clear hydrophobic coating boundary line is shown in the figure, proving that the conformal coating of Example 1 of the present application has good hydrophobic properties.

[0288] like Figure 7 As shown, Figure 7 This is a thermal analysis curve of the conformal coating obtained in Example 1 of the present application. It can be seen that the epitaxial starting temperature Te of the conformal coating of the present application is 360.7°C. The conformal coating of the present application can work at 200°C for a long time and can instantly reach 300°C. It can provide reliable protection for electronic circuit boards under extreme temperature conditions and has good high temperature resistance.

[0289] The present application also provides a method for erasing a cured film formed by a high-temperature resistant and erasable outdoor conformal coating, wherein a matching erasing solvent is used to erase the cured film formed by the conformal coating, and the conformal coating prepared in Example 1 of the present application is coated on two IPC standard circuit boards respectively, and waited for curing to form a cured film. The erasing method of the present application and the prior art are used to erase and compare the cured films on the two standard circuit boards, and the results are shown in Table 4.

[0290] Table 4

[0291]

[0292] From the above results, it can be seen that the use of the erasing solvent of the present application to erase the cured film formed by the three-proof paint has a good removal effect without residue, and it is proved that the erasing solvent will not cause damage to the circuit board itself, and is particularly suitable for precision devices such as electronic circuits.

[0293] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for general technical personnel in this field, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A heat-resistant erasable outdoor three-proof paint, characterized in that, The high-temperature resistant erasable outdoor three-proof paint comprises a solvent, methyl silicone oil, hydrogen-containing silicone oil, a catalyst, styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer; wherein, the mass of the styrene-isoprene block copolymer is 1%-15% of the total mass of the three-proof paint, the mass of the styrene-butadiene block copolymer is 1%-15% of the total mass of the three-proof paint, and the mass of the styrene-ethylene-butene-styrene block copolymer is 1%-5% of the total mass of the three-proof paint; The solvent is selected from one or more of petroleum ether, isooctane, isoheptane, and isohexane, and the mass of the solvent is 40%-80% of the total mass of the three-proof paint; The preparation method of the high-temperature resistant erasable outdoor three-proof paint comprises the following steps: S1. Weigh each component according to the ratio; S2. Add methyl silicone oil into the solvent and stir for dispersion for 1-2 h; S3. After adding the styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer, heat to 85-95 °C and stir for dispersion for 4-6 h; S4. Cool to room temperature; S5. Add hydrogen-containing silicone oil and a catalyst, and stir at room temperature overnight to obtain the final product.

2. The high temperature resistant and erasable outdoor conformal coating according to claim 1, characterized in that: The mass ratio among the styrene-isoprene block copolymer, styrene-butadiene block copolymer, and styrene-ethylene-butene-styrene block copolymer is 1-10:1-10:1-3.

3. The high-temperature resistant erasable outdoor three-proof paint according to claim 1, wherein The number-average molecular weight of the styrene-isoprene block copolymer is 50,000-150,000, the number-average molecular weight of the styrene-butadiene block copolymer is 55,000-150,000, and the number-average molecular weight of the styrene-ethylene-butene-styrene block copolymer is 70,000-220,000.

4. The high temperature resistant and erasable outdoor conformal coating according to claim 1, characterized in that: The solvent consists of isooctane and petroleum ether, and the mixing ratio of the isooctane and the petroleum ether is 5-7:3-5.

5. The high temperature resistant and erasable outdoor conformal coating according to claim 1, characterized in that: The mass of the methyl silicone oil is 3%-15% of the total mass of the three-proof paint, the viscosity range of the methyl silicone oil is 10,000-30,000 mPa·s, and the volatile content is less than 1%.

6. The high temperature resistant and erasable outdoor conformal coating according to claim 1, characterized in that: The mass of the hydrogen-containing silicone oil is 0.5%-5% of the total mass of the three-proof paint, the viscosity range of the hydrogen-containing silicone oil is 3000-10,000 mPa·s, and the volatile content is less than 1%.

7. The high temperature resistant and erasable outdoor conformal coating according to claim 1, characterized in that: The three-proof paint further comprises calcium carbonate, stearic acid, and UV pigment, the mass of the calcium carbonate is 0.5%-3% of the total mass of the three-proof paint, the mass of the stearic acid is 0.5%-3% of the total mass of the three-proof paint, and the mass of the UV pigment is 0.1%-0.5% of the total mass of the three-proof paint; and / or The catalyst is a Karstedt catalyst, and the mass of the Karstedt catalyst is 0.1%-0.5% of the total mass of the three-proof paint; and / or The three-proof paint further comprises water, and the mass of the water is 0.5%-2% of the total mass of the three-proof paint.

8. The high-temperature resistant erasable outdoor three-proof paint according to claim 1, characterized in that, In S2, before adding methyl silicone oil into the solvent, it further comprises mixing the solvent with calcium carbonate, stearic acid, and UV pigment, heating to 85-95 °C for dispersion for 1-2 h, and cooling to room temperature.

9. The heat-resistant erasable outdoor three-proof paint according to claim 1, characterized in that In S5, the catalyst is a Karstedt catalyst; and / or In S5, water is added dropwise within 1-2 h of stirring at room temperature.

10. A method for erasing a cured film formed by a high-temperature resistant erasable outdoor three-proof paint as described in any one of claims 1 to 9, characterized in that, A matching wiping solvent is used to wipe off the cured film formed by the three-proof paint, wherein the matching wiping solvent contains n-octane and petroleum ether.

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