Environment-friendly silicon steel sheet insulating paint and preparation method thereof

Abstract

The invention discloses an environment-friendly silicon steel sheet insulating paint and a preparation method thereof, and belongs to the technical field of paint preparation. Epoxy resin is dissolved through a CBE environment-friendly solvent and a CBM-1 environment-friendly solvent to replace xylene, so that the toxicity in the preparation reaction is reduced, and the silicon steel sheet insulating paint is more environment-friendly. Compared with xylene, the CBE environment-friendly solvent and the CBM-1 environment-friendly solvent have slight pungent smell or no pungent smell and lower VOC emission, so that the environment-friendly requirement is met, the harm to the body of a worker is reduced, and compared with a 40% epoxy resin solution, the organic silicon modified epoxy resin solution has higher heat resistance and better toughness due to difference of chemical bonds, so that the environment-friendly paint is more environment-friendly. Boron nitride can form a heat conduction network after the paint is cured, so that the heat conduction efficiency and the heat resistance are improved, meanwhile, nano-scale particles such as nano silicon dioxide can fill free volume, so that the mechanical property of the paint is improved, and the paint has good heat conduction performance. And zinc phosphate can form a passive film to inhibit electrochemical corrosion.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and in particular relates to an environmentally friendly silicon steel sheet insulating paint coating and a preparation method thereof. Background Art

[0002] At present, when electrical equipment is used, it is required that the electrical equipment should have good environmental adaptability, reduce the negative impact on the environment and resources, and adopt resource-saving, environmentally friendly and sustainable development technologies and processes. In this context, the application of environmentally friendly insulating materials in dry-type transformers has become particularly important.

[0003] Traditional coatings are relatively insufficient in heat resistance, breakdown strength and mechanical strength due to problems with raw material preparation. Moreover, among the various types of existing coatings, the vast majority are still solvent-based coatings. Solvents such as xylene, trimethylbenzene and cyclohexanone pose a great threat to the environment and personal safety, which is not conducive to human contact and environmental protection needs. Summary of the Invention

[0004] In order to overcome the above-mentioned defects, the present invention provides an environmentally friendly silicon steel sheet insulating paint coating and a preparation method thereof, which solves the problem that most coatings are still solvent-based coatings, and solvents such as xylene, trimethylbenzene, and cyclohexanone pose a great threat to the environment and personal safety, which is not conducive to human contact and environmental protection needs, and the traditional coatings have relatively insufficient heat resistance, breakdown strength and strength.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an environmentally friendly insulating paint coating for silicon steel sheet, wherein the insulating paint coating comprises the following raw materials in parts by weight: 50-100 parts by weight of epoxy resin, 2-5 parts by weight of MF980 amino resin, 3-10 parts by weight of CT-120 aldehyde ketone, 5-15 parts by weight of 284 phenolic resin, 1-5 parts by weight of ADP accelerator, 0.1-1 parts by weight of 835 leveling agent, 10-100 parts by weight of CBE environmentally friendly solvent, 10-100 parts by weight of CBM-1 environmentally friendly solvent, 1-5 parts by weight of boron nitride, 1-3 parts by weight of nano-silica, 1-4 parts by weight of zinc phosphate, 0.05-0.15 parts by weight of defoaming agent, 1-10 parts by weight of coupling agent, 0.1-0.5 parts by weight of catalyst, and 10-30 parts by weight of silicone prepolymer.

[0006] As a further solution of the present invention: the ADP accelerator is a modified imidazole compound, the 835 leveling agent is a polyether-modified polysiloxane, and the organosilicon prepolymer is a hydroxyl-terminated polydimethylsiloxane.

[0007] As a further solution of the present invention: the defoaming agent is nano aerogel, the coupling agent is glycidyloxypropyltrimethoxysilane, and the catalyst is dibutyltin dilaurate.

[0008] A method for preparing an environmentally friendly silicon steel sheet insulating paint coating, the method comprising the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool down to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then filter through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package it; S3, 20 parts by mass of an organosilicon prepolymer and 5 parts by mass of a coupling agent were mixed, stirred at 60° C. for 1 hour to generate an epoxy-terminated organosilicon prepolymer, and then the epoxy-terminated organosilicon prepolymer was slowly added dropwise to the prepared 40% epoxy resin solution, and 0.1 parts by mass of a catalyst was added, followed by step temperature control, adding 10-15 parts by mass of a CBE environmentally friendly solvent, adjusting the viscosity to 400-600 cps, maintaining at 25° C., and finally vacuum defoaming and filtering with a 5 μm filter bag to obtain an organosilicon-modified epoxy resin solution; S4. Add the organosilicon-modified epoxy resin solution to the reactor, start stirring at 300 r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent within 5 minutes, and increase the stirring speed to 500 r / min. Then add 8 parts by mass of CBM-1 environmentally friendly solvent and continue stirring for 10 minutes until it is completely transparent; S5, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S6, take 1 part by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S7, 1 part by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 1 part by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min; S8. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

[0009] As a further solution of the present invention: when slowly adding the epoxy-terminated organosilicon prepolymer dropwise in S3, the temperature needs to be raised to 80° C., and the dropping rate is controlled to be 1 ml / min.

[0010] As a further solution of the present invention: when adding 0.1 parts by mass of the catalyst in S3, nitrogen needs to be flushed into the reaction container and the pressure balance needs to be maintained.

[0011] As a further solution of the present invention: the step temperature control in S3 is divided into two stages, the temperature of the first stage is 80-100°C, the time is 2-3 hours, and the temperature of the second stage is 120 degrees Celsius, the time is 1-2 hours.

[0012] As a further solution of the present invention: when 1 part by mass of nano-silica in S6 is premixed with 0.2 parts by mass of 835 leveling agent, ultrasonic dispersion at 40 kHz is performed for 20-40 minutes.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, CBE environmentally friendly solvent, CBM-1 environmentally friendly solvent, epoxy resin, organosilicon prepolymer, catalyst and coupling agent are provided, and the epoxy resin is dissolved by CBE environmentally friendly solvent and CBM-1 environmentally friendly solvent instead of xylene to dissolve the epoxy resin, thereby reducing the toxicity during the preparation reaction. In addition, compared with xylene, CBE environmentally friendly solvent and CBM-1 environmentally friendly solvent have a slight or no irritating odor and lower VOC emissions, thereby meeting environmental protection requirements and reducing harm to the health of workers. A 40% epoxy resin solution is reacted with the organosilicon prepolymer, catalyst and coupling agent to prepare an organosilicon-modified epoxy resin solution. The organosilicon-modified epoxy resin solution has higher heat resistance and better toughness than the 40% epoxy resin solution due to different chemical bond chains, thereby improving the comprehensive performance of the insulating paint coating.

[0014] 2. In the present invention, boron nitride, nano-silica, zinc phosphate, MF980 amino resin, CT-120 aldehyde ketone and 284 phenolic resin are provided, and 284 phenolic resin, CT-120 aldehyde ketone and MF980 amino resin are added to the obtained organosilicon-modified epoxy resin solution in sequence for mixing reaction, thereby ensuring the high-temperature resistance, adhesion and heat curing performance of the coating. Boron nitride can form a heat-conducting network after the coating is cured, thereby improving thermal conductivity and heat resistance. At the same time, nano-scale particles such as nano-silica can fill the free volume and react with resin compounds such as epoxy resin or MF980 amino resin to form specific chemical bonds, thereby improving the mechanical properties of the coating. Zinc phosphate can form a passivation film to inhibit electrochemical corrosion. DETAILED DESCRIPTION

[0015] The technical solution of the present application will be further described in detail below in conjunction with specific implementation methods.

[0016] The present invention provides a technical solution: an environmentally friendly silicon steel sheet insulating varnish coating and a preparation method thereof.

[0017] Example 1: Disclosed is an environmentally friendly insulating varnish coating for silicon steel sheets. The insulating varnish coating comprises the following raw materials, measured in parts by weight: 40 parts by weight of epoxy resin, 3 parts by weight of MF980 amino resin, 4 parts by weight of CT-120 aldehyde ketone, 9 parts by weight of 284 phenolic resin, 1.8 parts by weight of ADP accelerator, 1 part by weight of 835 leveling agent, 90 parts by weight of CBE environmentally friendly solvent, 40 parts by weight of CBM-1 environmentally friendly solvent, 1 part by weight of boron nitride, 1 part by weight of nano-silica, 1 part by weight of zinc phosphate, 0.05 parts by weight of defoaming agent, 5 parts by weight of coupling agent, 0.1 part by weight of catalyst, and 20 parts by weight of silicone prepolymer.

[0018] A method for preparing an environmentally friendly silicon steel sheet insulating paint coating, the preparation method comprising the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool down to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then filter through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package it; S3, 20 parts by mass of an organosilicon prepolymer and 5 parts by mass of a coupling agent were mixed, stirred at 60° C. for 1 hour to generate an epoxy-terminated organosilicon prepolymer, and then the epoxy-terminated organosilicon prepolymer was slowly added dropwise to the prepared 40% epoxy resin solution, and 0.1 parts by mass of a catalyst was added, followed by step temperature control, adding 10-15 parts by mass of a CBE environmentally friendly solvent, adjusting the viscosity to 400-600 cps, maintaining at 25° C., and finally vacuum defoaming and filtering with a 5 μm filter bag to obtain an organosilicon-modified epoxy resin solution; S4. Add the organosilicon-modified epoxy resin solution to the reactor, start stirring at 300 r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent within 5 minutes, and increase the stirring speed to 500 r / min. Then add 8 parts by mass of CBM-1 environmentally friendly solvent and continue stirring for 10 minutes until it is completely transparent; S5, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S6, take 1 part by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S7, 1 part by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 1 part by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min; S8. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

[0019] Example 2: Disclosed is an environmentally friendly insulating varnish coating for silicon steel sheets. The insulating varnish coating comprises the following raw materials, measured in parts by weight: 40 parts by weight of epoxy resin, 3 parts by weight of MF980 amino resin, 4 parts by weight of CT-120 aldehyde ketone, 9 parts by weight of 284 phenolic resin, 1.8 parts by weight of ADP accelerator, 1 part by weight of 835 leveling agent, 90 parts by weight of CBE environmentally friendly solvent, 40 parts by weight of CBM-1 environmentally friendly solvent, 1 part by weight of boron nitride, 1 part by weight of nano-silicon dioxide, 1 part by weight of zinc phosphate, and 0.05 part by weight of defoaming agent.

[0020] A method for preparing an environmentally friendly silicon steel sheet insulating paint coating, the preparation method comprising the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool down to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then filter through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package it; S3, take 40% epoxy resin solution and add it to the reactor, start stirring at 300r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent, add it within 5 minutes, and increase the stirring speed to 500r / min, then add 8 parts by mass of CBM-1 environmentally friendly solvent, and continue stirring for 10 minutes until it is completely transparent; S4, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S5, take 1 part by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S6, 1 part by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 1 part by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min; S7. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

[0021] The difference between Example 2 and Example 1 is that in Example 2, silicone prepolymer, catalyst and coupling agent are not used to react with 40% epoxy resin solution to prepare silicone-modified epoxy resin solution, but 40% epoxy resin solution is directly used to participate in the subsequent steps to complete the coating preparation.

[0022] Example 3: Disclosed is an environmentally friendly insulating varnish coating for silicon steel sheets. The insulating varnish coating comprises the following raw materials, measured in parts by weight: 40 parts by weight of epoxy resin, 3 parts by weight of MF980 amino resin, 4 parts by weight of CT-120 aldehyde ketone, 9 parts by weight of 284 phenolic resin, 1.8 parts by weight of ADP accelerator, 1 part by weight of 835 leveling agent, 90 parts by weight of CBE environmentally friendly solvent, 40 parts by weight of CBM-1 environmentally friendly solvent, 0.5 parts by weight of boron nitride, 0.5 parts by weight of nano-silica, 0.5 parts by weight of zinc phosphate, 0.05 parts by weight of defoaming agent, 5 parts by weight of coupling agent, 0.1 parts by weight of catalyst, and 20 parts by weight of silicone prepolymer.

[0023] A method for preparing an environmentally friendly silicon steel sheet insulating paint coating, the preparation method comprising the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool down to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then filter through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package it; S3, 20 parts by mass of an organosilicon prepolymer and 5 parts by mass of a coupling agent were mixed, stirred at 60° C. for 1 hour to generate an epoxy-terminated organosilicon prepolymer, and then the epoxy-terminated organosilicon prepolymer was slowly added dropwise to the prepared 40% epoxy resin solution, and 0.1 parts by mass of a catalyst was added, followed by step temperature control, adding 10-15 parts by mass of a CBE environmentally friendly solvent, adjusting the viscosity to 400-600 cps, maintaining at 25° C., and finally vacuum defoaming and filtering with a 5 μm filter bag to obtain an organosilicon-modified epoxy resin solution; S4. Add the organosilicon-modified epoxy resin solution to the reactor, start stirring at 300 r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent within 5 minutes, and increase the stirring speed to 500 r / min. Then add 8 parts by mass of CBM-1 environmentally friendly solvent and continue stirring for 10 minutes until it is completely transparent; S5, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S6, take 0.5 parts by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S7, 0.5 parts by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 0.5 parts by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min; S8. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

[0024] Example 4: Disclosed is an environmentally friendly insulating varnish coating for silicon steel sheets. The insulating varnish coating comprises the following raw materials, measured in parts by weight: 40 parts by weight of epoxy resin, 3 parts by weight of MF980 amino resin, 4 parts by weight of CT-120 aldehyde ketone, 9 parts by weight of 284 phenolic resin, 1.8 parts by weight of ADP accelerator, 1 part by weight of 835 leveling agent, 90 parts by weight of CBE environmentally friendly solvent, 40 parts by weight of CBM-1 environmentally friendly solvent, 1.2 parts by weight of boron nitride, 1.2 parts by weight of nano-silicon dioxide, 1.2 parts by weight of zinc phosphate, 0.05 parts by weight of defoaming agent, 5 parts by weight of coupling agent, 0.1 parts by weight of catalyst, and 20 parts by weight of silicone prepolymer.

[0025] A method for preparing an environmentally friendly silicon steel sheet insulating paint coating, the preparation method comprising the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool down to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then filter through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package it; S3, 20 parts by mass of an organosilicon prepolymer and 5 parts by mass of a coupling agent were mixed, stirred at 60° C. for 1 hour to generate an epoxy-terminated organosilicon prepolymer, and then the epoxy-terminated organosilicon prepolymer was slowly added dropwise to the prepared 40% epoxy resin solution, and 0.1 parts by mass of a catalyst was added, followed by step temperature control, adding 10-15 parts by mass of a CBE environmentally friendly solvent, adjusting the viscosity to 400-600 cps, maintaining at 25° C., and finally vacuum defoaming and filtering with a 5 μm filter bag to obtain an organosilicon-modified epoxy resin solution; S4. Add the organosilicon-modified epoxy resin solution to the reactor, start stirring at 300 r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent within 5 minutes, and increase the stirring speed to 500 r / min. Then add 8 parts by mass of CBM-1 environmentally friendly solvent and continue stirring for 10 minutes until it is completely transparent; S5, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S6, take 1.2 parts by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S7, 1.2 parts by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 1.2 parts by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min. S8. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

[0026] The difference between Example 1, Example 3 and Example 4 is that: in Example 1, there are 1 part by mass of boron nitride, 1 part by mass of nano-silicon dioxide, and 1 part by mass of zinc phosphate; in Example 3, there are 0.5 part by mass of boron nitride, 0.5 part by mass of nano-silicon dioxide, and 0.5 part by mass of zinc phosphate; and in Example 4, there are 1.2 parts by mass of boron nitride, 1.2 parts by mass of nano-silicon dioxide, and 1.2 parts by mass of zinc phosphate.

[0027] The following table is obtained based on Examples 1-4:

[0028] From the comparison in the above table we can see that: The insulating paint prepared by silicone modified epoxy resin solution has higher heat resistance, better oil resistance and stronger mechanical strength than the insulating paint prepared by 40% epoxy resin solution alone, which is conducive to high temperature In addition, adding a certain amount of boron nitride, nano-silicon dioxide and zinc phosphate for reaction mixing during the preparation of insulating paint can further improve the drying efficiency, oil resistance, heat resistance and mechanical strength of the paint, thereby improving the overall performance.

[0029] In summary: Using CBE environmentally friendly solvent and CBM-1 environmentally friendly solvent to dissolve epoxy resin can reduce the toxicity during the preparation reaction. Compared with xylene, CBE environmentally friendly solvent and CBM-1 environmentally friendly solvent have mild or no irritating odor and lower VOC emissions, thereby meeting environmental protection needs and reducing harm to the health of workers. A 40% epoxy resin solution is reacted with a silicone prepolymer, a catalyst and a coupling agent to prepare a silicone-modified epoxy resin solution. The insulating paint coating prepared by the silicone-modified epoxy resin solution has higher heat resistance and better toughness, thereby improving the performance of the insulating paint coating. In the preparation process, a certain amount of boron nitride, nano-silica and zinc phosphate are added for reaction, which can further improve the drying efficiency, oil resistance, heat resistance and mechanical strength of the coating, thereby improving the comprehensive performance.

[0030] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0032] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the descriptions with reference to the terms "one scheme", "some schemes", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the scheme or example are included in at least one scheme or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more schemes or examples.

Claims

1. An environmentally friendly silicon steel sheet insulating paint coating, characterized by: The insulating paint coating comprises the following raw materials in parts by weight: 50-100 parts by weight of epoxy resin, 2-5 parts by weight of MF980 amino resin, 3-10 parts by weight of CT-120 aldehyde ketone, 5-15 parts by weight of 284 phenolic resin, 1-5 parts by weight of ADP accelerator, 0.1-1 parts by weight of 835 leveling agent, 10-100 parts by weight of CBE environmentally friendly solvent, 10-100 parts by weight of CBM-1 environmentally friendly solvent, 1-5 parts by weight of boron nitride, 1-3 parts by weight of nano-silicon dioxide, 1-4 parts by weight of zinc phosphate, 0.05-0.15 parts by weight of defoaming agent, 1-10 parts by weight of coupling agent, 0.1-0.5 parts by weight of catalyst, and 10-30 parts by weight of silicone prepolymer.

2. The environmentally friendly insulating paint for silicon steel sheets according to claim 1, characterized in that: The ADP accelerator is a modified imidazole compound, the 835 leveling agent is a polyether-modified polysiloxane, and the organosilicon prepolymer is a hydroxyl-terminated polydimethylsiloxane.

3. The environmentally friendly insulating paint for silicon steel sheets according to claim 1, characterized in that: The defoaming agent is nano aerogel, the coupling agent is glycidyloxypropyltrimethoxysilane, and the catalyst is dibutyltin dilaurate.

4. A method for preparing an environmentally friendly insulating varnish for silicon steel sheets, according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: S1. Mix 50 parts by mass of CBE eco-friendly solvent and 10 parts by mass of CBM-1 eco-friendly solvent, heat to 40-50°C, then slowly add 40 parts by mass of epoxy resin in batches, continue stirring, rotate at 300-500 rpm, dissolve for 2-3 hours, and use a high-speed shearing disperser at a speed of 1000-1500 rpm for 30 minutes to ensure that there are no visible particles; S2. Cool to below 30°C, add 0.15 parts by mass of 835 leveling agent and 0.05 parts by mass of defoamer in sequence, stir and mix at low speed for 10 minutes, then pass through a 5μm filter bag to remove impurities to prepare a 40% epoxy resin solution, and package; S3, 20 parts by mass of an organosilicon prepolymer and 5 parts by mass of a coupling agent were mixed, stirred at 60° C. for 1 hour to generate an epoxy-terminated organosilicon prepolymer, and then the epoxy-terminated organosilicon prepolymer was slowly added dropwise to the prepared 40% epoxy resin solution, and 0.1 parts by mass of a catalyst was added, followed by step temperature control, adding 10-15 parts by mass of a CBE environmentally friendly solvent, adjusting the viscosity to 400-600 cps, maintaining the mixture at 25° C., and finally vacuum defoaming and filtering with a 5 μm filter bag to obtain an organosilicon-modified epoxy resin solution; S4. Add the organosilicon-modified epoxy resin solution to the reactor, start stirring at 300 r / min, maintain the temperature at 25°C, then slowly add 25 parts by mass of CBE environmentally friendly solvent within 5 minutes, and increase the stirring speed to 500 r / min. Then add 8 parts by mass of CBM-1 environmentally friendly solvent and continue stirring for 10 minutes until it is completely transparent; S5, then add 9 parts by mass of 284 phenolic resin in 3 batches, with an interval of 5 minutes between each batch, and then inject 4 parts by mass of CT-120 aldehyde ketone in a thin stream, and simultaneously raise the temperature to 35°C; S6, take 1 part by mass of nano-silica and 0.2 parts by mass of 835 leveling agent and pre-mix them, inject them into the solution obtained in S5 and stir them for 15 minutes at a stirring speed of 1200r / min, then take 2.6 parts by mass of MF980 amino resin and add them dropwise, the addition time is ≥10 minutes, the pH is controlled at 7-8, and the resulting solution is kept warm; S7, 1 part by mass of boron nitride was mixed with 5 parts by mass of CBM-1 environmentally friendly solvent, and ball milled for 2 hours at a speed of 300 rpm to form a stable slurry. After that, the temperature of the solution obtained in S6 was raised to 30-45 ° C, and the slurry was slowly added. The reaction time was 1-2 hours and stirred. After that, 1.8 parts by mass of ADP accelerator was diluted with 9 parts by mass of CBM-1 environmentally friendly solvent and added dropwise. After 5 minutes, 1 part by mass of zinc phosphate was taken and mixed and stirred. Finally, 0.2 parts by mass of 835 leveling agent was added and the stirring speed was 600 r / min; S8. Adjust the stirring speed to 800r / min and maintain it for 30-40 minutes. Finally, filter it through a 10μm nylon filter bag and let it stand for 15 minutes to defoam. The obtained paint is then filled and sealed for storage.

5. The method for preparing an environmentally friendly silicon steel sheet insulating varnish coating according to claim 4, characterized in that: When slowly adding the epoxy-terminated organosilicon prepolymer dropwise into S3, the temperature needs to be raised to 80° C., and the dropping rate is controlled to be 1 ml / min.

6. The method for preparing an environmentally friendly silicon steel sheet insulating varnish coating according to claim 4, characterized in that: When adding 0.1 parts by mass of the catalyst in S3, nitrogen gas needs to be flushed into the reaction container and the pressure balance needs to be maintained.

7. The method for preparing an environmentally friendly insulating varnish for silicon steel sheets according to claim 4, characterized in that: The step temperature control in S3 is divided into two stages. The temperature of the first stage is 80-100°C for 2-3 hours, and the temperature of the second stage is 120°C for 1-2 hours.

8. The method for preparing an environmentally friendly silicon steel sheet insulating varnish coating according to claim 4, characterized in that: When 1 part by mass of nano-silica and 0.2 parts by mass of 835 leveling agent in the S6 are premixed, ultrasonic dispersion at 40 kHz is performed for 20-40 minutes.

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