High-performance environment-friendly single-component pure epoxy resin insulating paint and preparation method thereof

Abstract

The invention relates to high-performance environment-friendly single-component pure epoxy resin insulating paint and a preparation method thereof. The high-performance environment-friendly single-component pure epoxy resin insulating paint comprises the following components in percentage by mass: 60-80% of epoxy resin, 5-10% of a reactive diluent, 5-8% of modified silicon dioxide, 3-10% of a curing agent, 3-8% of a flexibilizer, 1-3% of a thixotropic agent and 1-3% of other auxiliaries, wherein the modified silicon dioxide is silicon dioxide modified by alkyl acid and a silane coupling agent. The modified silicon dioxide, the epoxy resin, the auxiliaries and other components are compounded to obtain the single-component insulating paint, the single-component insulating paint has the advantages of being good in storage stability, high in curing speed, good in paint film flexibility, high in water resistance and corrosion resistance and the like, meanwhile, the preparation method is simple, the components are green and environmentally friendly, and the problems existing in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint technology, in particular to a high-performance environmentally friendly single-component pure epoxy resin insulating paint and a preparation method thereof. BACKGROUND

[0002] Epoxy resin insulating paint is widely used in the fields of motors, transformers, electronic components, etc. due to its good electrical insulation, mechanical properties and chemical stability. With the increasing awareness of environmental protection and the increasingly stringent environmental protection regulations, the development of environmentally friendly insulating paint has become a trend. Traditional epoxy resin insulating paint is mostly solvent-based, containing a large amount of volatile organic solvents (VOCs), which not only pollutes the environment, but also harms human health, and is flammable and explosive, posing a safety hazard.

[0003] Single-component epoxy resin insulating paint greatly simplifies the process flow and saves operation time due to its convenience of use and no need for on-site blending. This type of product is of great significance to the improvement of production efficiency, the rapid completion of emergency repair, and relatively small on-site construction environment, and therefore is favored in practical applications. Single-component epoxy resin insulating paint has been widely used in the fields of winding impregnation of various motors such as generators and motors, insulation treatment of transformer coils, encapsulation and coating of electronic components such as transformers, and metal parts requiring insulation protection; especially in scenarios requiring rapid turnaround or mass production, its dispensing-free feature becomes a key factor for significantly improving production efficiency, reducing labor costs and operation error rate.

[0004] However, existing single-component pure epoxy resin insulating paint still has some performance deficiencies, such as rapid increase in storage viscosity, slow curing speed, which seriously affects the use process and production efficiency; reduced insulation performance and service life of the cured film; poor water resistance and corrosion resistance, and the insulation performance is easily affected in humid and corrosive environments. In addition, improper selection of raw materials and process control during the preparation of some single-component pure epoxy resin insulating paint leads to unstable product performance and uneven quality.

[0005] Therefore, it is of great practical significance to develop a new high-performance environmentally friendly single-component pure epoxy resin insulating paint product. SUMMARY

[0006] Therefore, the present application provides a high-performance environmentally friendly single-component pure epoxy resin insulating paint and a preparation method thereof. The single-component insulating paint is prepared by compounding modified silicon dioxide, epoxy resin, and additives, etc. It has good storage stability, fast curing speed, good film flexibility, strong water resistance and corrosion resistance, etc. The preparation method is simple and the ingredients are environmentally friendly, overcoming the problems in the prior art.

[0007] One object of the present application is to provide a high-performance environmentally friendly single-component pure epoxy resin insulating paint, which comprises the following components by mass fraction:

[0008] Epoxy resin 60-80%

[0009] Active diluent 5-10%

[0010]

[0011] The modified silica is silica modified by alkyl acid and silane coupling agent.

[0012] The high-performance environmentally friendly single-component pure epoxy resin insulating paint of the present application does not use volatile organic solvents at all, reduces pollution to the environment and harm to the health of construction personnel, and meets environmental protection requirements; and the ingredients are selected from low-toxicity or non-toxic raw materials, such as epoxy resin, active diluent, modified silica, etc., thereby reducing the toxicity of the product from the source.

[0013] Further, the epoxy resin is an epoxy resin with an epoxy value of 0.4-0.6 mol / 100g.

[0014] Further, the active diluent is selected from active diluents containing epoxy groups.

[0015] Further, the curing agent is selected from amine latent curing agents.

[0016] The latent curing agent can maintain good storage stability at room temperature, and can initiate a curing reaction only under specific temperature or conditions, facilitating storage and transportation, and also meeting the needs of different construction processes. The amine latent curing agent is used in the present application to be compounded with other ingredients, realizing rapid curing at a lower temperature, reducing energy consumption, and improving production efficiency. Compared with traditional single-component epoxy resin insulating paint, the curing time can be shortened by 30-50%, and it is also suitable for some temperature-sensitive substrates or occasions.

[0017] Further, the toughening agent is selected from one or more of carboxyl-terminated butyl nitrile rubber and polyether polyol.

[0018] Preferably, the toughening agent is carboxyl-terminated butyl nitrile rubber (CTBN).

[0019] The carboxyl-terminated butyl nitrile rubber toughening agent with flexible segments can chemically react with components such as epoxy resin, introducing flexible segments into the crosslinked network, effectively improving the flexibility of the paint film, thereby preventing paint film cracking and improving the service life of the insulating paint. The paint film can be bent 50-100 times, and there is no obvious cracking after 100 cycles of -45℃-155℃ temperature impact test.

[0020] Further, the other auxiliary agents include dispersants, defoamers and leveling agents.

[0021] The thixotropic agent of fumed silica and modified silica are mixed in different mesh ratios, which can make the insulating paint have better fluidity during construction, facilitate impregnation and penetration, and quickly increase viscosity when static to prevent sagging and dripping, ensure that the resin can be retained in the relaxed winding and other parts, and improve the film thickness on the enameled wire and insulating tape.

[0022] The present application improves the electrical insulation performance of the insulating paint by optimizing the formula and preparation process, has high insulation resistance, low dielectric loss and other characteristics, and the volume resistivity can reach 10 14 -10 15 Ω·m, the normal medium loss factor is 0.1-0.3%, the dielectric strength is 30-40MV / m, which meets the strict requirements of electrical equipment on insulation performance; at the same time, the mechanical strength, toughness, wear resistance of the cured insulating paint are also enhanced, and the chemical stability of acid and alkali resistance, salt spray resistance and aging resistance is improved, the service life and application range of the insulating paint are prolonged. In the water resistance test, the paint film has no blistering, peeling and other phenomena after soaking in water for 72h, and the surface resistance retention rate is more than 90%; in the salt spray corrosion test, the paint film has no obvious corrosion phenomenon after 500h salt spray test, and the adhesion remains good.

[0023] Further, the modified silica is the product obtained by reacting hydroxylated silica with alkyl acid first and then with epoxy silane coupling agent.

[0024] Further, the preparation method of the high-performance environment-friendly single-component pure epoxy resin insulating paint comprises the following steps:

[0025] S1, mixing alkyl acid and hydroxylated silica, and obtaining an intermediate product after ultrasonic heating reaction;

[0026] S2, mixing the intermediate product and epoxy silane coupling agent, and obtaining modified silica after heating reaction;

[0027] S3, mixing active diluent and part of epoxy resin, and obtaining a premix liquid after heating and stirring;

[0028] S4, mixing toughening agent and the remaining epoxy resin, and obtaining toughening agent modified epoxy resin after heating and stirring reaction;

[0029] S5, mixing thixotropic agent, modified silica and the premix liquid, dispersing, and then adding the toughening agent modified epoxy resin, curing agent and other auxiliary agents, and stirring uniformly to obtain the high-performance environment-friendly single-component pure epoxy resin insulating paint.

[0030] Further, the mass ratio of the alkyl acid and the hydroxylated silicon dioxide is (0.1-0.5):1.

[0031] Further, the mass ratio of the intermediate product and the epoxy silane coupling agent is 1:(1-5).

[0032] The present application develops a simple and efficient preparation process, reduces the production steps and time, reduces the production cost, and is beneficial to batch production and other large-scale production processes, has a short process flow, simple operation, reduces energy consumption and waste discharge, and realizes green production.

[0033] Preferably, the preparation method of the hydroxylated silicon dioxide comprises the following steps:

[0034] The fumed silicon dioxide (particle size ≤100 nm) is added into a mixed solution of concentrated sulfuric acid and hydrogen peroxide with a mass ratio of 70:30, heated to 80℃, reacted for 2h, filtered, washed and dried to obtain the hydroxylated fumed silicon dioxide.

[0035] The present application has the following beneficial effects:

[0036] In the high-performance environment-friendly single-component pure epoxy resin insulating paint of the present application, modified silicon dioxide is used as a component to be compounded with epoxy resin, diluent, toughening agent and other components, the modified silicon dioxide is first reacted with hydroxylated silicon dioxide and long-chain alkyl acid, and then further grafted with epoxy silane coupling agent through the remaining hydroxyl groups, thereby introducing alkyl chains and epoxy groups onto the surface of the silicon dioxide. On the one hand, the dispersion effect of the silicon dioxide is enhanced, and the hydrophobic and entanglement effects brought by the long alkyl chain segment are also beneficial to improving the water resistance, stability and mechanical strength of the film layer. On the other hand, the introduced epoxy groups can enable the modified silicon dioxide to be combined with epoxy resin, amine latent curing agent and carboxyl-terminated butyronitrile rubber toughening agent through chemical bonds, further improve the compatibility between the components, and the integrated crosslinked structure formed also enables the film layer to have better comprehensive performance, overcoming the problems in the prior art. DETAILED DESCRIPTION

[0037] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment methods appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0038] The words "preferred" and "preferably" in the application refer to embodiments of the application that can provide certain benefits under certain circumstances. However, other embodiments can also be preferred under the same or other circumstances. Additionally, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude those other embodiments from the scope of the application.

[0039] It should be understood that, except where noted otherwise, or otherwise evident from context, expressions of amount or all numbers in the specification and claims, such as, for example, amounts of ingredients, are understood as being modified by the term "about". Thus, unless otherwise indicated, the numerical parameters set forth in the following specification and attached claims are approximations.

[0040] The epoxy resin in the embodiment of the application is E51 bisphenol A type epoxy resin.

[0041] The active diluent in the embodiment of the application is HK-66.

[0042] The curing agent in the embodiment of the application is dicyandiamide.

[0043] The toughening agent in the embodiment of the application is CTBN 1300X13.

[0044] The thixotropic agent in the embodiment of the application is a mixture of fumed silica with specific surface area 200 and fumed silica with specific surface area 380 in a mass ratio of 1:1.

[0045] The other auxiliary agent in the embodiment of the application is a mixture of leveling agent BYK-310 and defoaming agent 2410AC in a mass ratio of 1:1.

[0046] Example 1

[0047] A high-performance environmentally friendly single-component pure epoxy resin insulating paint, comprising the following components in mass fraction:

[0048]

[0049] The preparation method of the high-performance environmentally friendly single-component pure epoxy resin insulating paint comprises the following steps:

[0050] S1, stearic acid and hydroxylated silicon dioxide in a mass ratio of 0.1:1 are mixed with toluene as a solvent, and after ultrasonic reaction at 80℃ for 12h, filtration and drying are performed to obtain an intermediate product;

[0051] S2, mixing the intermediate product and KH-560 in a mass ratio of 1:2 with a mixed solution of ethanol and water in a volume ratio of 3:1 as a solvent, refluxing at 90°C for 24h, filtering, washing, and drying to obtain modified silica;

[0052] S3, mixing the active diluent and 1 / 2 mass of epoxy resin according to the above mass fraction, stirring at 200r / min for 30min at 55°C to obtain a premix;

[0053] S4, mixing the toughening agent and the remaining epoxy resin, stirring and reacting at 80°C for 2h to obtain a toughening agent modified epoxy resin;

[0054] S5, mixing the thixotropic agent, the modified silica, and the premix at 1000r / min for 20min, then adding the toughening agent modified epoxy resin, the curing agent, and other additives, stirring at 300r / min for 60min at room temperature to obtain the high-performance environmentally friendly single-component pure epoxy resin insulating paint.

[0055] Example 2

[0056] A high-performance environmentally friendly single-component pure epoxy resin insulating paint, comprising the following components in mass fraction:

[0057]

[0058] A preparation method of the high-performance environmentally friendly single-component pure epoxy resin insulating paint, comprising the following steps:

[0059] S1, mixing stearic acid and hydroxylated silica in a mass ratio of 0.1:1 with toluene as a solvent, ultrasonic reacting at 80°C for 12h, filtering, and drying to obtain an intermediate product;

[0060] S2, mixing the intermediate product and KH-560 in a mass ratio of 1:2 with a mixed solution of ethanol and water in a volume ratio of 3:1 as a solvent, refluxing at 90°C for 24h, filtering, washing, and drying to obtain modified silica;

[0061] S3, mixing the active diluent and 1 / 2 mass of epoxy resin according to the above mass fraction, stirring at 200r / min for 30min at 55°C to obtain a premix;

[0062] S4, mixing the toughening agent and the remaining epoxy resin, stirring and reacting at 80°C for 2h to obtain a toughening agent modified epoxy resin;

[0063] S5, mix the thixotropic agent, the modified silica and the premix liquid, disperse at 1000 r / min for 20 min, then add the toughener modified epoxy resin, curing agent and other auxiliaries, stir at 300 r / min at room temperature for 60 min, to obtain the high-performance environmentally friendly single-component pure epoxy resin insulating paint.

[0064] Example 3

[0065] A high-performance environmentally friendly single-component pure epoxy resin insulating paint, the high-performance environmentally friendly single-component pure epoxy resin insulating paint comprises the following components by mass fraction:

[0066]

[0067] The preparation method of the high-performance environmentally friendly single-component pure epoxy resin insulating paint comprises the following steps:

[0068] S1, mix stearic acid and hydroxylated silicon dioxide with a mass ratio of 0.1:1 with toluene as solvent, ultrasonic reaction at 80℃ for 12h, then filter, dry, to obtain an intermediate product;

[0069] S2, mix the intermediate product and KH-560 with a mass ratio of 1:2 with a mixture of ethanol and water with a volume ratio of 3:1 as solvent, reflux reaction at 90℃ for 24h, filter, wash, dry, to obtain modified silica;

[0070] S3, mix active diluent and 1 / 2 mass of epoxy resin according to the above mass fraction, stir at 200 r / min at 55℃ for 30 min, to obtain a premix liquid;

[0071] S4, mix toughener and the remaining epoxy resin, stir and react at 80℃ for 2h, to obtain a toughener modified epoxy resin;

[0072] S5, mix the thixotropic agent, the modified silica and the premix liquid, disperse at 1000 r / min for 20 min, then add the toughener modified epoxy resin, curing agent and other auxiliaries, stir at 300 r / min at room temperature for 60 min, to obtain the high-performance environmentally friendly single-component pure epoxy resin insulating paint.

[0073] Comparative Example 1

[0074] The difference between Comparative Example 1 and Example 1 is that steps S1-S2 are modified as follows:

[0075] Mix stearic acid and hydroxylated silicon dioxide with a mass ratio of 1:1 with toluene as solvent, ultrasonic reaction at 80℃ for 12h, then filter, dry, to obtain modified silica;

[0076] The other components and preparation method are the same as those of Example 1.

[0077] Comparative Example 2

[0078] Comparative Example 2 differs from Example 1 in that steps S1-S2 are modified as follows:

[0079] A mixture of hydroxylated silica and KH-560 in a mass ratio of 1:3 is mixed with an ethanol and water mixture in a volume ratio of 3:1 as a solvent, and refluxed at 90℃ for 24h, filtered, washed, and dried to obtain modified silica;

[0080] The other components and preparation methods are the same as in Example 1.

[0081] Test Example

[0082] The high-performance environmentally friendly single-component pure epoxy resin insulating paint prepared in Example 1 and Comparative Examples 1-2 is subjected to performance testing.

[0083] Test Method:

[0084] The gel time, storage stability, surface drying time, curing volatile matter, medium loss factor, volume resistivity, electrical strength, adhesion strength, temperature shock test, and salt spray resistance test are performed in accordance with the standards of GB / T 15022.2-2017, GB / T 1981.2-2009, GB / T 150.5A-2009, GB / T 2423.17-2008, etc.

[0085] The test results are shown in Table 1.

[0086] Table 1 Performance Test Results

[0087]

[0088] According to Table 1, it can be concluded that the high-performance environmentally friendly single-component pure epoxy resin insulating paint prepared in the example has good stability and corrosion resistance, fast curing speed, and excellent dielectric properties, adhesion, and other properties, and can meet the needs of different application fields. The comparative examples 1-2 replace the modified silica and only use fatty acids or silane coupling agents as modifiers, resulting in reduced bonding strength and compatibility between components, and the synergistic effect between different components is not ideal, and the performance of the paint product decreases to varying degrees.

[0089] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other embodiments without departing from the spirit or essential characteristics of the application. The embodiments should, therefore, be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0090] Furthermore, it should be understood that although the description is made on embodiments, not every embodiment contains only one independent technical solution, and the description is made in this way only for the sake of clarity, and a person skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can also be combined appropriately to form other embodiments that can be understood by a person skilled in the art.

Claims

1. A high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish, characterized in that: The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish comprises the following components by mass fraction: Wherein, the modified silica is silica modified by alkyl acid and silane coupling agent.

2. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The epoxy resin has an epoxy value of 0.4-0.6 mol / 100g.

3. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The reactive diluent is selected from reactive diluents containing epoxy groups.

4. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The curing agent is selected from amine latent curing agents.

5. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The toughening agent is selected from one or more of carboxyl-terminated nitrile rubber and polyether polyol.

6. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The other additives include dispersants, defoamers and leveling agents.

7. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 1, characterized in that: The modified silica is a product obtained by reacting hydroxylated silica with an alkyl acid and then with an epoxy silane coupling agent.

8. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 7, characterized in that: The preparation method of the high-performance environmentally friendly one-component pure epoxy resin insulating varnish comprises the following steps: S1, mixing an alkyl acid and hydroxylated silica, and reacting them by ultrasonic heating to obtain an intermediate product; S2, mixing the intermediate product and an epoxy silane coupling agent, heating and reacting to obtain modified silica; S3, mixing the reactive diluent and part of the epoxy resin, heating and stirring to obtain a premixed solution; S4, mixing the toughening agent and the remaining epoxy resin, heating and stirring to react, to obtain a toughening agent modified epoxy resin; S5. Mix the thixotropic agent, modified silicon dioxide and the premixed liquid, disperse them, add the toughening agent modified epoxy resin, curing agent and other additives, and stir evenly to obtain the high-performance environmentally friendly one-component pure epoxy resin insulating paint.

9. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 8, characterized in that: The mass ratio of the alkyl acid to the hydroxylated silica is (0.1-0.5):

1.

10. The high-performance, environmentally friendly, one-component pure epoxy resin insulating varnish according to claim 8, characterized in that: The mass ratio of the intermediate product to the epoxy silane coupling agent is 1:(1-5).

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