Washing-free insulating paint as well as preparation method and application thereof

Abstract

The invention relates to the field of insulating paint, in particular to washing-free insulating paint as well as a preparation method and application thereof. The washing-free insulating paint comprises the following components in parts by mass: 9-61 parts of etherified epoxy resin; 3-27 parts of thermoplastic acrylic resin; 0.05 to 0.2 part of a cooling agent; 0.5 to 3 parts of a flame retardant; and 30-50 parts of deionized water. The etherified epoxy resin improves the compatibility with deionized water; the thermoplastic acrylic resin improves the toughness, the adhesive force, the corrosion resistance, the quick-drying property and the like of a formed paint film; the cooling agent is beneficial to curing at a relatively low temperature to form a paint film, high-temperature curing is not needed, and the influence on electronic elements is reduced; the flame retardant improves the flame retardant grade, is non-flammable and non-explosive during welding of electronic components, and is higher in safety. The insulating paint can be used for electronic component pins and the like, an insulating paint film is formed after curing, a foot washing procedure is not needed during welding, the formed insulating paint film can be gasified and disappear at the welding temperature, and the welding conductive effect cannot be affected.

Description

Technical Field

[0001] This application relates to the field of insulating varnishes, and particularly to a solderless insulating varnish and its preparation method and applications. Background Art

[0002] The pins of existing electronic components are often coated with insulating varnish to improve their insulation performance, moisture resistance, and corrosion resistance, extend their service life, and prevent problems such as poor contact and short circuits caused by damaged pins.

[0003] However, when electronic components are soldered, such as when soldering electronic components to a PCB board, the insulating paint films formed by these insulating varnishes will affect the soldering effect, resulting in poor soldering, poor conductivity at the soldering point, or difficult soldering. The electronic components cannot be soldered to the PCB board, the soldering fails or the efficiency is low, affecting the production speed. Therefore, in the prior art, the insulating varnish on the pins often has to be removed first, generally by washing, burning, grinding, etc. The most common method is to wash it off with chemical agents, which is called "washing the pins" or "washing the feet" in the industry. In addition, if the pin cleaning in the foot washing process is not in place, the soldering effect will still be affected. Moreover, the foot washing process often requires adding carriers and operating stations, increasing the cost. Finally, traditional insulating varnishes often use aromatic hydrocarbons or ester solvents, which are flammable and explosive. If the foot washing is not in place, there is still a high risk in the subsequent soldering process when encountering high temperatures.

[0004] Therefore, an insulating varnish is needed that can protect electronic components during normal use when coated on the pins of electronic components, and can be directly soldered without the need for the foot washing process when soldering is required. That is, a solderless insulating varnish is needed. Summary of the Invention

[0005] The purpose of this application is to provide a solderless insulating varnish and its preparation method and applications, aiming to solve the technical problem that the insulating varnish in the prior art requires an additional foot washing process before soldering after being used on electronic components.

[0006] To achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a solderless insulating varnish, which includes the following components in parts by mass:

[0008]

[0009] The no-clean insulating varnish of the present application changes from the insulating varnish of the existing organic solvent system to the insulating varnish of the water-based insulating varnish system. The etherified modified epoxy resin is beneficial to improving the compatibility with deionized water and is not easily denatured; the thermoplastic acrylic resin synergistically with the etherified epoxy resin further improves the properties of the no-clean insulating varnish such as the toughness, adhesion, corrosion resistance, and quick drying property of the formed paint film, and it will soften until gasify during welding; the cooling agent is beneficial to the no-clean insulating varnish to cure to form a paint film at a lower temperature, without high-temperature curing, reducing the impact on electronic components; the flame retardant improves the flame retardant grade of the no-clean insulating varnish, and it is not easily flammable or explosive during the welding of electronic components, with higher safety. Moreover, the composition is insulating after forming a paint film. Therefore, the no-clean insulating glue of the present application can be used for electronic component pins, etc., and can form an insulating paint film to protect electronic components after curing, and there is no need for a foot washing process during welding. At the welding temperature, the formed insulating paint film will gasify and disappear, without affecting the welding conductivity effect.

[0010] In a second aspect, the present application provides a preparation method of the above no-clean insulating varnish of the present application, including the following steps:

[0011] Raw materials including etherified epoxy resin, cooling agent, and flame retardant are sequentially added to deionized water for mixing treatment.

[0012] In the preparation method of the present application, the etherified epoxy resin and the thermoplastic acrylic resin are first added to deionized water in a certain proportion to make the substrate fully mixed and uniform, and then other components are added and fully mixed and uniform. The etherified epoxy resin, the cooling agent, and the flame retardant interact with each other, so that the prepared no-clean insulating varnish can be cured at a low temperature to form an insulating paint film to protect electronic components. When the electronic components need to be welded, there is no need for a foot washing process and can be directly welded. At the welding temperature, the insulating paint film gasifies and disappears, is not easily flammable or explosive, and does not affect the welding conductivity effect. The preparation method has controllable process, and the prepared no-clean insulating varnish has stable performance.

[0013] In a third aspect, the present application provides an application of the above no-clean insulating varnish of the present application or the no-clean insulating varnish prepared by the above preparation method of the present application in the welding of electronic components.

[0014] Since the no-clean insulating varnish of the present application does not require a baking process when used for electronic components, it can be cured at a low temperature to form an insulating paint film to protect electronic components. And, when welding is carried out, there is no need for a process of washing the pins, saving the process flow. The paint film formed at the high temperature of welding will gasify and disappear, is not easily flammable or explosive, and does not affect the welding conductivity effect. Specific embodiments

[0015] In order to make the technical problems to be solved, technical solutions and beneficial effects of this application clearer and more understandable, the following further elaborates on this application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0016] In this application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and back associated objects.

[0017] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following items" or its similar expressions refer to any combination of these items, including any combination of single items or plural items.

[0018] It should be understood that in various embodiments of this application, the magnitudes of the serial numbers of the above processes do not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0019] The weights of the relevant components mentioned in the specification of the embodiments of this application can not only refer to the specific contents of each component, but also represent the proportional relationship of the weights between the components. Therefore, as long as the contents of the relevant components in the specification of the embodiments of this application are enlarged or reduced in proportion, they are within the scope disclosed in the specification of the embodiments of this application. Specifically, the mass in the specification of the embodiments of this application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0020] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of this application, the first XX can also be called the second XX, and similarly, the second XX can also be called the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0021] The first aspect of the embodiments of this application provides a wash-free insulating paint, including the following components in parts by mass:

[0022]

[0023] In the embodiment of the present application, the solvent-free insulating paint changes from the insulating paint of the existing organic solvent system to the insulating paint of the water-based insulating paint system. The etherified modified epoxy resin is beneficial to improving the compatibility with deionized water and is not easily denatured; the thermoplastic acrylic resin synergistically with the etherified epoxy resin further improves the properties of the solvent-free insulating paint such as toughness, adhesion, corrosion resistance, and quick drying property of the formed paint film, and will soften until gasify during welding; the cooling agent is beneficial to the solvent-free insulating paint to cure to form a paint film at a lower temperature, without high-temperature curing, reducing the impact on electronic components; the flame retardant improves the flame retardant grade of the solvent-free insulating paint, is not easy to burn or explode during the welding of electronic components, and has higher safety. Moreover, the composition is insulating after forming a paint film. Therefore, the solvent-free insulating glue in the embodiment of the present application can be used for electronic component pins, etc., and can form an insulating paint film to protect electronic components after curing, and there is no need for a washing process during welding. At the welding temperature, the formed insulating paint film will gasify and disappear, without affecting the welding conductivity effect.

[0024] In addition, the solvent-free insulating paint in the embodiment of the present application is an aqueous solution system composition, which greatly reduces the amount of organic solvents compared with the prior art, is more environmentally friendly and reduces costs.

[0025] Regarding etherified epoxy resin

[0026] Etherified epoxy resin, especially glycidyl ether epoxy resin, is generally obtained by etherifying phenol and alcohol under acidic conditions to form phenol ether, and then undergoing a condensation reaction with epichlorohydrin. It contains polar hydroxyl groups and ether bonds, can form chemical bonds or adsorb other interfaces, and has good adhesion performance; at the same time, it can also form a three-dimensional network structure under the action of a curing agent or a certain temperature, so it has excellent mechanical properties, such as high strength, toughness and wear resistance. During the curing process, the curing reaction is mainly completed by a series of ring-opening addition polymerization reactions of the epoxy groups in the molecule, so the shrinkage rate during curing is low, and the internal stress generated is small, which helps to improve the adhesion performance and reduce the cracks of the formed paint film. At the same time, etherified epoxy resin does not contain conductive active groups and free ions, and is an excellent insulating material with high dielectric performance, surface leakage resistance and arc resistance, which is beneficial to the solvent-free insulating paint to have outstanding electrical insulation performance after forming a paint film.

[0027] Optionally, the etherified epoxy resin is a highly etherified epoxy resin or a fully etherified epoxy resin. The higher the degree of etherification, the better the adhesion performance, and at the same time, the better the compatibility with deionized water, and it can be used as a water-based epoxy resin. If the degree of etherification is too low or it is a conventional epoxy resin, it will turn white and denature when added to deionized water.

[0028] Regarding thermoplastic acrylic resin

[0029] Thermoplastic acrylic resins can be used in no-clean insulating paints in combination with etherified epoxy resins. The main reason is that the unsaturated bonds of the acrylic resin and the epoxy groups of the etherified epoxy resin can undergo a cross-linking reaction synergistically, which is beneficial to improving the toughness of the paint film formed by the no-clean insulating paint, enhancing the gloss and adhesion, and also conducive to improving the corrosion resistance and weather resistance of the paint film. Moreover, the thermoplastic acrylic resin will soften and even vaporize when heated, which is beneficial for the paint film formed by the no-clean insulating paint to vaporize and disappear during welding, ensuring the welding conductivity effect.

[0030] In some embodiments, the number-average molecular weight of the thermoplastic acrylic resin can be 75,000 - 120,000. In exemplary embodiments, the thermoplastic acrylic resin can be water-soluble or alcohol-soluble. Among them, the alcohol-soluble acrylic resin has good alcohol solubility, and the formed film has characteristics such as high gloss, high hardness, high softening point, and no yellowing. When the electronic components are sensitive to solvents, and when the raw materials of other components in the no-clean insulating paint are dissolved in alcohol solvents, the alcohol-soluble acrylic resin can be particularly considered for this thermoplastic acrylic resin. At the same time, in addition to deionized water, alcohol solvents can be appropriately added to the solvent in the no-clean insulating paint, and the film formation is rapid and the odor is small.

[0031] Regarding the cooling agent

[0032] After traditional insulating paint is painted, a baking process is required to cure the paint to form a paint film. Adding a cooling agent to the no-clean insulating paint in the embodiments of the present application is beneficial for the no-clean insulating paint to reduce the reaction temperature, and it can cure to form a paint film at a lower temperature, without the need for baking and high-temperature curing. The paint film still has high quality, improving the efficiency, and at the same time reducing the impact on electronic components.

[0033] In some embodiments, the cooling agent includes an acid catalyst. In exemplary embodiments, the acid catalyst can include dinonylnaphthalene disulfonic acid (DNNDSA), dodecylbenzenesulfonic acid (DDBSA). The acid catalyst can be selected as cooling agents of models such as NACURE X49-110, NACURE 5225, NACURE 5225 of King Industries, Inc. in the United States. These cooling agents are beneficial for reducing the baking process and lowering the curing temperature. In exemplary embodiments, the prepared insulating paint can cure to form a paint film at a low temperature of 90°C for 2 hours. Moreover, these cooling agents are applicable to water-based paint materials, and can promote the cross-linking reaction of the insulating paint during curing through catalytic action, improving the adhesion, corrosion resistance, flexibility, and impact resistance of the formed paint film. Furthermore, these cooling agents have good solubility and reaction activity, which helps to reduce the energy consumption and emissions during the curing of the insulating paint, meeting the environmental protection requirements.

[0034] Regarding the flame retardant

[0035] The addition of flame retardants makes the paint less flammable, especially in the subsequent welding process, thereby improving the safety of the wash-free insulating paint. In some embodiments, the flame retardant may include a halogen-free flame retardant. The halogen-free flame retardant does not contain halogen, so it does not produce toxic gases such as dioxins during the flame retardant effect, is environmentally friendly, and complies with relevant regulations of multiple countries and regions.

[0036] In some embodiments, the halogen-free flame retardant includes at least one of a nitrogen-based flame retardant and a phosphate-based flame retardant. Among them, the nitrogen-based flame retardant may include dicyandiamide (dicyandiamide), which is easily soluble in deionized water, non-toxic and flammable, and decomposes at high temperatures to produce non-flammable gases such as nitrogen, carbon dioxide and water vapor, which can dilute the flammable gas and reduce the oxygen concentration in the combustion area, thereby slowing down or preventing the combustion process, and these decomposition products are also non-toxic and harmless. At the same time, the decomposition reaction of dicyandiamide can also absorb a large amount of heat, reduce the temperature of the material, and further inhibit combustion.

[0037] Phosphate flame retardants may include tributyl phosphate, which contains phosphate groups and decomposes at high temperatures to produce non-combustible gases such as water vapor, which can take away the heat from the combustion surface, thereby reducing the temperature and slowing down the combustion rate. In addition, the non-combustible gases produced can also dilute the concentration of combustible gases and oxygen in the combustion area, reducing the intensity of combustion. Phosphate flame retardants can also form a phosphate protective layer during the combustion process, isolating the combustibles from oxygen, thereby preventing the combustion from proceeding.

[0038] The halogen-free flame retardant may be a mixture of dicyandiamide and tributyl phosphate, wherein the mass ratio of dicyandiamide to tributyl phosphate is (0.3-2):1. In the exemplary embodiment, it may include but is not limited to any value of 0.3:1, 0.6:1, 1:1, 2:1 or a range between any two values. The flame retardant containing these two components has a better flame retardant effect, and has better compatibility with deionized water and etherified epoxy resin, and has almost no effect on other properties of the wash-free insulating paint. In addition, the two flame retardants are reactive flame retardants, and can also react with the etherified epoxy resin to a certain extent during the curing process of the insulating paint, which is conducive to the curing to form a paint film.

[0039] Deionized water is the solvent of no-wash insulating varnish. The above ingredients can be mixed with deionized water to make water-based insulating varnish, which can be applied on electronic components, such as the pins of electronic components. After curing, an insulating protective varnish film is formed, which can be directly welded without washing the pins.

[0040] In addition to the above main components, other components may be added to the wash-free insulating paint. In an exemplary embodiment, at least one of a pH regulator, a leveling agent, and a curing agent may be added.

[0041] About pH Adjusters

[0042] The pH regulator is mainly used to adjust and control the pH value of the waterborne solvent-free insulating paint to ensure the stable performance of the paint and the best painting effect. It has a significant impact on the storage stability, anti-corrosion performance, viscosity, and film properties of the paint. Maintaining an appropriate pH range is beneficial to improving the adhesion, water resistance, chemical resistance, etc. of the waterborne solvent-free insulating paint, and at the same time extending its shelf life. In the demonstration example, the pH regulator may include organic amine alcohols. The organic amine alcohols can be selected from methyl ethanolamine, dimethyl ethanolamine, diethanolamine, triethanolamine, etc. The organic amine alcohols have relatively low volatility and relatively weak irritation to the environment.

[0043] Due to the addition of components such as the aforementioned cooling agent, the overall system may be acidic, which is not conducive to the compatibility of etherified epoxy resin and water. Optionally, adding a pH regulator to adjust the pH value of the solvent-free insulating paint to a neutral or slightly alkaline state of 7-8 has many advantages. On the one hand, since the solvent-free insulating paint contains etherified epoxy resin, the solvent-free insulating paint exhibits an emulsion form. The organic particles in these emulsions are more likely to carry negative charges in an alkaline environment. Like charges repel each other, which is conducive to the emulsion particles being evenly dispersed in water without aggregation, flocculation, or precipitation, thus ensuring the stability of the waterborne solvent-free insulating paint during storage and use. Moreover, an appropriate alkaline pH value can adjust the viscosity and rheology of the waterborne solvent-free insulating paint, making it have better fluidity and leveling property, being easier to coat evenly and flatly during use, reducing defects such as sagging, and improving the construction efficiency and quality. Finally, during the film-forming process of the waterborne solvent-free insulating paint, an alkaline environment helps the fusion and cross-linking of resin particles. When the water evaporates, the resin particles can better fuse with each other under alkaline conditions to form a uniform, continuous, and dense paint film, improving the quality and performance of the paint film. Of course, the above alkalinity cannot be too strong, otherwise it will affect the base materials such as aluminum, zinc, and copper in the electronic components. Preferably, it is the above-mentioned neutral or slightly alkaline, with a pH of 7-8.

[0044] Regarding the leveling agent

[0045] The leveling agent can reduce the surface tension and surface viscosity of the coating, improve the fluidity and leveling property of the solvent-free insulating paint, make the paint easier to flow and spread during the coating process, so as to obtain a smoother and more uniform paint film, reduce defects such as orange peel, shrinkage holes, fish eyes, and pinholes, and improve the gloss and flatness of the coating. In the demonstration example, the leveling agent may include at least one of silicone leveling agents and acrylate leveling agents. In the demonstration example, the leveling agent may include the BYK-346 model of BYK Chemie.

[0046] Regarding the curing agent

[0047] When the solvent-free insulating paint in the embodiments of the present application does not contain a curing agent, it can be applied to electronic components and then dried at a low temperature to form a cured paint film. Or a curing agent can be added to accelerate the curing efficiency, and even drying may not be required. The curing agent can be an amine curing agent, including polyamines, polyamides, polyetheramines, etc., which have a fast reaction speed and a short curing time. Or it can be an acid anhydride curing agent. The curing agent can open the epoxy groups of the etherified epoxy resin and further react to form a three-dimensional network structure, improving the hardness and strength of the formed paint film, as well as the wear resistance and stability of the paint film.

[0048] During long-term storage, the curing agent can be stored separately from the aforementioned components to prevent premature curing, and the curing agent is added during use. When stored in the short term, the curing agent and the aforementioned components can also be mixed, but air needs to be isolated.

[0049] Regarding the entire solvent-free insulating paint

[0050] The above-mentioned etherified epoxy resin, cooling agent, flame retardant, and deionized water are formulated to obtain a solvent-free insulating paint. Each component functions separately, enabling the solvent-free insulating paint to be applied to electronic components such as electronic component pins and cured at a low temperature to form an insulating paint film to protect the electronic components. When the electronic components need to be welded, the washing feet process can be omitted and welding can be directly carried out. At the welding temperature, the insulating paint film vaporizes and disappears, is not flammable or explosive, and will not affect the welding and conductivity effect.

[0051] Among them, the etherified epoxy resin and the thermoplastic acrylic resin are used as the main materials of the solvent-free insulating paint. The sum of their masses can account for 30% - 60% of the total mass of the solvent-free insulating paint. The higher the mass ratio, the thicker the solvent-free insulating paint. In the exemplary embodiments, it can include, but is not limited to, any percentage among 30%, 40%, 50%, 60% or the range between any two percentages. The mass ratio of the etherified epoxy resin to the thermoplastic acrylic resin has a great influence on the performance of the solvent-free insulating paint. In the embodiments, the mass ratio of the etherified epoxy resin to the thermoplastic acrylic resin can be 1:(0.3 - 0.5). In the exemplary embodiments, it can include, but is not limited to, any ratio among 1:0.3, 1:0.4, 1:0.5 or the range between any two ratios. Through the dosage and ratio of the above-mentioned main materials, it is beneficial to synergistically improve the adhesion, quick-drying property, toughness, corrosion resistance and other properties of the solvent-free insulating paint.

[0052] Among them, the components in the solventless insulating paint can be in the following parts by mass: 9 to 61 parts of etherified epoxy resin. In the demonstration examples, it can include but is not limited to any value among 9 parts, 20 parts, 30 parts, 40 parts, 50 parts, 61 parts or the range between any two values. 3 to 27 parts of thermoplastic acrylic resin. In the demonstration examples, it can include but is not limited to any value among 3 parts, 10 parts, 17 parts, 23 parts, 27 parts or the range between any two values. 0.05 to 0.2 part of cooling agent. In the demonstration examples, it can include but is not limited to any value among 0.05 part, 0.08 part, 0.1 part, 0.15 part, 0.2 part or the range between any two values. 0.5 to 3 parts of flame retardant. In the demonstration examples, it can include but is not limited to any value among 0.5 part, 0.8 part, 1 part, 2 part, 3 parts or the range between any two values. 30 to 50 parts of deionized water. In the demonstration examples, it can include but is not limited to any value among 30 parts, 35 parts, 40 parts, 45 parts, 50 parts or the range between any two values.

[0053] When a pH regulator is included, the parts by mass can be 0.2 to 3 parts. In the demonstration examples, it can include but is not limited to any value among 0.2 part, 0.8 part, 1.5 parts, 2 parts, 3 parts or the range between any two values. When a leveling agent is included, the parts by mass can be 0.15 to 0.5 part. In the demonstration examples, it can include but is not limited to any value among 0.15 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part or the range between any two values. When a curing agent is included, the parts by mass can be 0.2 to 1 part. In the demonstration examples, it can include but is not limited to any value among 0.2 part, 0.4 part, 0.6 part, 0.8 part, 1 part or the range between any two values.

[0054] Furthermore, the solventless insulating paint can include the following components in parts by mass to improve properties such as the stability, curing performance, and welding volatilization of the paint:

[0055]

[0056] For other additive components such as pH regulators, leveling agents, curing agents, etc., the addition amounts can refer to those above.

[0057] Furthermore, when the solventless insulating paint includes the following components in parts by mass, the properties of the solventless insulating paint are optimal:

[0058]

[0059] Upon testing, the pH value of the solventless insulating paint is 7 to 8. The formed paint film can maintain stable insulating performance at a certain temperature, and the heat resistance level can reach Class F to Class H according to the American UL (Underwriters Laboratories) standard, that is, 150°C to 180°C. The flame retardant grade can reach 94V0.

[0060] The second aspect of the embodiment of the present application provides a method for preparing the wash-free insulating varnish of the embodiment of the above application, comprising the following steps:

[0061] S10: adding raw materials including etherified epoxy resin, thermoplastic acrylic resin, cooling agent and flame retardant into deionized water in sequence for mixing.

[0062] The preparation method of the embodiment of the present application first adds etherified epoxy resin and thermoplastic acrylic resin to deionized water in a certain proportion, mixes the base material thoroughly and evenly, and then adds other components and mixes thoroughly and evenly. The etherified epoxy resin, cooling agent and flame retardant interact with each other, so that the prepared washable insulating paint can be cured at low temperature to form an insulating paint film to protect electronic components. When electronic components need to be welded, they can be directly welded without the need for a foot washing process. At the welding temperature, the insulating paint film vaporizes and disappears, is non-flammable and non-explosive, and will not affect the welding conductive effect. The preparation method is process controllable, and the prepared wash-free insulating paint has stable performance.

[0063] A third aspect of the embodiments of the present application provides an application of the no-clean insulating varnish of the above embodiment of the application or the no-clean insulating varnish prepared by the preparation method of the above embodiment of the application in welding of electronic components.

[0064] Because the wash-free insulating paint of the above-mentioned application embodiment is used for electronic components, no baking process is required, and it can be cured at low temperature to form an insulating paint film to protect the electronic components. In addition, when welding, there is no need to wash the pins, which saves the process flow. The paint film formed at the high temperature of welding will gasify and disappear, is not flammable and explosive, and will not affect the welding conductive effect.

[0065] The following describes the invention in conjunction with specific embodiments.

[0066] Example 1

[0067] This embodiment provides a wash-free insulating varnish and a preparation method thereof. The wash-free insulating varnish includes the following components in parts by weight:

[0068]

[0069] Among them, the cooling agent is NACURE X49-110 model from King Industries of the United States; the pH adjuster is an amine adjuster; the flame retardant is melamine and tributyl phosphate in a mass ratio of 1:1; the leveling agent is BYK-346 model from BYK Chemical; and the curing agent is an amine curing agent.

[0070] The preparation method comprises the following steps:

[0071] S1: first add etherified epoxy resin and thermoplastic acrylic resin into deionized water and stir evenly;

[0072] S2: Then, add a coolant, a flame retardant, and a leveling agent into the above solution respectively and stir.

[0073] S3: Then, add a pH regulator into the above solution to adjust the pH value of the solution to a neutral value of 7 - 8.

[0074] S4: Finally, add a curing agent into the solution and apply it to electronic components to obtain a solvent - free insulating paint.

[0075] Example 2

[0076] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0077] Example 3

[0078] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0079] Example 4

[0080] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0081] Example 5

[0082] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0083] Example 6

[0084] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0085] Example 7

[0086] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that the weight parts of the components are adjusted, and the others are the same. See Table 1 for details.

[0087] Example 8

[0088] This example provides a solvent - free insulating paint and its preparation method. The difference from Example 1 is only that no leveling agent is added, and the others are the same. See Table 1 for details.

[0089] The differences in components among Examples 1 to 8 are shown in Table 1.

[0090] Table 1

[0091]

[0092]

[0093] Verification of the Wash-free Effect

[0094] Apply the wash-free insulating varnish provided in the above Examples 1 to 8 on electronic components such as diodes, rectifiers, and capacitors. After curing to form a paint film, test that its insulation performance is good.

[0095] Then weld these electronic components onto the PCB board by soldering. During the soldering process, the paint film directly vaporizes without impurity residue. After soldering, test that these electronic components in contact with the PCB board are in good contact and have good electrical conductivity.

[0096] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A wash-free insulating paint, characterized in that, It comprises components in the following parts by mass:

2. The water-free insulating paint according to claim 1, characterized in that: The mass ratio of the etherified epoxy resin to the thermoplastic acrylic resin is 1:(0.3 - 0.5); and / or, the sum of the masses of the etherified epoxy resin and the thermoplastic acrylic resin accounts for 30% - 60% of the total mass of the solvent-free insulating paint.

3. The solvent-free insulating paint according to claim 2, wherein: The cooling agent comprises an acid catalyst; and / or, the flame retardant comprises a halogen-free flame retardant, and the halogen-free flame retardant comprises a mixture of dicyandiamide and tributyl phosphate, and the mass ratio of dicyandiamide to tributyl phosphate is (0.3 - 2):

1.

4. The solvent-free insulating paint according to any one of claims 1 to 3, characterized in that, It comprises components in the following parts by mass:

5. The solvent-free insulating paint according to any one of claims 1 to 3, characterized in that, It comprises components in the following parts by mass: The etherified epoxy resin: 20 parts The thermoplastic acrylic resin: 6 - 10 parts 6. The solvent-free insulating paint according to any one of claims 1 to 3, characterized in that: The solvent-free insulating paint further comprises a pH regulator, and the mass of the pH regulator is 0.2 - 3 parts; and / or, the solvent-free insulating paint further comprises a leveling agent, and the mass of the leveling agent is 0.15 - 0.5 parts; and / or, the solvent-free insulating paint further comprises a curing agent, and the mass of the curing agent is 0.2 - 1 part.

7. The air-drying insulating paint according to claim 6, characterized in that: The pH regulator comprises an alcohol amine organic compound; and / or, the leveling agent comprises at least one of an organosilicon leveling agent and an acrylate leveling agent; and / or, the curing agent comprises an epoxy resin curing agent.

8. The solvent-free insulating paint according to any one of claims 1 to 3 or 7, characterized in that: The pH value of the solvent-free insulating paint is 7 - 8.

9. A preparation method of the wash-free insulating paint according to any one of claims 1 to 8, characterized in that, It comprises the following steps: Raw materials including the etherified epoxy resin, the thermoplastic acrylic resin, the cooling agent, and the flame retardant are sequentially added to the deionized water for mixing treatment.

10. Application of the solvent-free insulating paint according to any one of claims 1 - 8 or the solvent-free insulating paint prepared by the preparation method according to claim 9 in the welding of electronic components.

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