Silicon steel insulation coating paint for core dispensing forming

Abstract

The application discloses a silicon steel insulation coating paint for core dispensing forming, which comprises the following components in parts by mass: water-soluble metal phosphate 100 parts, water-dispersible organic resin 20-160 parts, and adhesive function promoter 7-18 parts. The application has good insulation, adhesion, heat resistance, punching, welding and other basic properties, and can also endow the coated silicon steel with good adhesive properties after the core dispensing process, and the coated silicon steel has fast curing speed and high adhesive strength, thereby improving the core fixing strength and solving the problems of vibration noise and core efficiency caused by low inherent frequency, and is especially suitable for coating on thin-gauge high-grade non-oriented silicon steel plates of new energy motor, servo motor, micro motor and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of silicon steel insulation coating paint, and particularly relates to a silicon steel insulation coating paint for core dispensing forming. BACKGROUND

[0002] Motor core forming generally has four methods of bolt fastening, riveting, welding and bonding, among which the bonding method has the characteristics of no damage to the core magnetic circuit, high bonding strength, wide applicability, etc., and the manufactured core has the characteristics of high efficiency, small magnetic vibration noise and high fixing strength, etc., and is particularly suitable for advanced motors such as new energy vehicle drive motors and robot servo motors.

[0003] In the prior art, special C-3 type (ASTM A976 standard) self-bonding coating silicon steel such as CN 201810275197.8 and CN 201610197722.X disclosed can be selected to realize the inter-sheet bonding process, but it is limited to the high price of the material, the incomplete maturity of the current application market, the incompleteness of the self-bonding silicon steel specifications and the difficulty in obtaining, so the core punching sheet factory actively seeks dispensing process to realize inter-sheet bonding.

[0004] The core loose sheet dispensing adhesive forming technology is developed by referring to the surface mount technology (SMT) of integrated circuits, and the adhesive performance is determined by the selection of adhesive, its process and equipment, but more and more applications find that the variety of silicon steel coating or the composition of coating has a significant influence on the adhesive performance, and even directly determines whether the core dispensing process is feasible; however, the manufacturing technology is currently in the small-batch trial production stage, and the market application promotion has not yet reached a scale, and the disclosed patents such as CN 202010530524.7 are basically concentrated in the core dispensing equipment technology, and the information related to the dispensing characteristics of the core raw material such as silicon steel coating is basically blank.

[0005] In view of the above situation, it is urgent to develop a C-5 coating property (ASTM A976 standard) core dispensing functional silicon steel environment-friendly insulation coating which can adapt to more types of core dispensing adhesives on the basis of having conventional film coating features, and has fast curing speed and high bonding strength. SUMMARY

[0006] In view of the above defects in the prior art, the purpose of the present application is to provide a silicon steel insulation coating paint for core dispensing forming, which has good insulation, adhesion, heat resistance, punching, welding and other basic properties, and also has good adhesive performance after the coating silicon steel is treated by the core dispensing process, and has fast curing speed and high adhesive strength, thereby improving the vibration noise and core efficiency problems caused by low core fixing strength and natural frequency, and is particularly suitable for coating on thin-gauge high-grade non-oriented silicon steel sheets for new energy motors, servo motors and micro-motors.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] The present application provides a silicon steel insulation coating paint for core dispensing forming, comprising the following components by mass fraction:

[0009] Water-soluble metal phosphate 100 parts;

[0010] Water-dispersible organic resin 20-160 parts;

[0011] Adhesive function promoter 7-18 parts.

[0012] Preferably, the water-soluble metal phosphate contains one or more water-soluble phosphates of aluminum, zinc, magnesium, and calcium.

[0013] Preferably, the water-soluble aluminum phosphate is selected from one or more of aluminum dihydrogen phosphate, aluminum dihydrogen tripolyphosphate, aluminum monohydrogen phosphate, and aluminum phosphate.

[0014] Preferably, the mass fraction of the water-dispersible organic resin is 25-100 parts.

[0015] Preferably, the water-dispersible organic resin is selected from one or more of polyester emulsion, polyurethane emulsion, polyacrylate emulsion, and polyvinyl acetate emulsion.

[0016] Preferably, the water-dispersible organic resin is a composite emulsion of cationic polyurethane emulsion and polyacrylate emulsion.

[0017] Preferably, the mass fraction of the adhesive function promoter is 10-15 parts.

[0018] Preferably, the adhesive function promoter comprises the following components by mass fraction:

[0019] Soluble metal ion salt 2-9 parts;

[0020] Hydrophilic nano-oxide dispersion liquid 1-8 parts;

[0021] The balance is a high-boiling-point moisturizing polyol;

[0022] The hydrophilic nano-oxide dispersion liquid is calculated based on the solid mass of nano-oxide.

[0023] Preferably, the mass fraction of the soluble metal ion salt is 3-6 parts.

[0024] Preferably, the soluble metal ion salt is an inorganic metal ion salt or an organic metal ion salt that can be dissolved in a water solution with pH < 2.0.

[0025] Preferably, the soluble metal ion salt is selected from one or more of a chloride of Fe, a sulfate of Fe, a nitrate of Fe, a phosphate of Fe, a chloride of Cu, a sulfate of Cu, a nitrate of Cu, a phosphate of Cu, a chloride of Mn, a sulfate of Mn, a nitrate of Mn, a phosphate of Mn, organic copper lithium R2CuLi, copper acetate, and ferric citrate FeC6H5O7.

[0026] Preferably, the hydrophilic nano-oxide dispersion liquid has a mass fraction of 2-5 parts based on the solid mass of the nano-oxide.

[0027] Preferably, the nano-oxide in the hydrophilic nano-oxide dispersion liquid is composed of colloidal SiO2 and Si / Al / Ti fumed oxide; the colloidal SiO2 is provided in the form of a colloidal silica aqueous solution, with an average particle size D50 of 5-20 nm; and the Si / Al / Ti fumed oxide is provided in the form of fumed nano-oxide particle powder generated by high-temperature flame decomposition of Si / Al / Ti raw materials, with an average particle size D50 of 5-15 nm.

[0028] Preferably, the colloidal SiO2 and the Si / Al / Ti fumed oxide particles have a solid mass fraction ratio of 1-3:1.

[0029] Preferably, the colloidal SiO2 has an average particle size D50 of 8-15 nm.

[0030] Preferably, in the hydrophilic nano-oxide dispersion liquid, the agglomerates formed after dispersion of the Si / Al / Ti fumed oxide have an average particle size D50 of 0.05-0.35 µm.

[0031] Preferably, the high-boiling-point humectant polyol has a boiling point ≥180°C.

[0032] Preferably, the high-boiling-point humectant polyol is selected from one or more of ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, butylene glycol, hexylene glycol, sorbitol, and xylitol.

[0033] The silicon steel insulation coating paint for core dispensing forming provided by the present application has the following beneficial effects:

[0034] 1. The silicon steel insulation coating paint for core dispensing forming of the present application, on the basis of having good basic properties such as insulation, adhesion, heat resistance, punching, and welding, can also impart good adhesive properties to the coated silicon steel after core dispensing process, and has fast curing speed and high adhesive strength, thereby improving the core fixing strength and the vibration noise and core efficiency problems caused by low inherent frequency, and is particularly suitable for coating on thin-gauge high-grade non-oriented silicon steel sheets for new energy motor, servo motor, and micro special motor.

[0035] 2、The silicon steel insulation coating paint for core dispensing forming of the present application, in addition to the basic performance of the conventional C-5 coating, the coating silicon steel has good adhesive properties after being dispensed with adhesive, which is manifested as fast initial solidification speed (initial solidification speed ≥ 1 N / mm2@3 min, i.e. initial solidification speed ≥ 1 N / mm2 within 3 minutes after solidification) and high adhesive strength (adhesive strength ≥ 4 N / mm2@60 min, i.e. adhesive strength ≥ 4 N / mm2 after 60 min of solidification), which is widely applicable to the types of adhesives currently used in core dispensing process;

[0036] 3、The silicon steel insulation coating paint for core dispensing forming of the present application is a non-hazardous chemical product, has low VOC emission and is green and environmentally friendly, and can be applied to the surface of silicon steel sheets used in various motors, especially micro and special motors, servo motors, automobile drive motors and other emerging fields, and the unique dispensing adhesive properties thereof significantly improve the performance of motor core vibration noise, motor efficiency and other properties, and have great commercial application value. BRIEF DESCRIPTION OF DRAWINGS

[0037] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the following drawings:

[0038] Figure 1 Fig. 1 is a schematic diagram of the coating falling amount at the cutout after punching of a cross-linking and curing film-forming coating, wherein (a) is a schematic diagram of the coating falling amount at the cutout after punching of a cross-linking and curing film-forming coating, and (b) is a schematic diagram of the coating falling amount at the cutout after punching of the silicon steel insulation coating for core dispensing forming in Example 1 of the present application;

[0039] Figure 2 Fig. 3 is a comparison diagram of the adhesive effect of the silicon steel sheet coated with the insulation coating in Example 1 of the present application after being treated by the core dispensing process and the cross-linking and curing film-forming coating;

[0040] Figure 3 Fig. 4 is a diagram showing the relationship between the mass fraction of the water-dispersible organic resin and the performance of the silicon steel insulation coating for core dispensing forming in Example 1 of the present application;

[0041] Figure 4 Fig. 5 is a diagram showing the relationship between the curing time and the adhesive strength of the silicon steel insulation coating paint using different soluble metal ion salts in Example 2 of the present application. DETAILED DESCRIPTION

[0042] In order to better understand the above technical solutions of the present application, the technical solutions of the present application will be further described below in conjunction with examples.

[0043] The silicon steel insulation coating paint for core dispensing forming provided by the present application is mainly suitable for the silicon steel water dispersible environment-friendly C-5 type silicon steel insulation coating for processing the punching core dispersion dispensing process, and the silicon steel insulation coating paint for core dispensing forming includes the following components in mass fraction:

[0044] Water-soluble metal phosphate 100 parts;

[0045] Water-dispersible organic resin 20-160 parts;

[0046] Adhesion function promoter 7-18 parts.

[0047] The water-soluble metal phosphate and the water-dispersible organic resin are film-forming components, the water-soluble metal phosphate contains one or more water-soluble phosphates of aluminum, zinc, magnesium, calcium and the like, and even a plurality of components other than the conventional dihydrogen phosphate, as long as the pH is less than 2.0 (25 DEG C, 1 atm, 40 wt% mass concentration) and the solution has good compatibility stability (the solution is still clear and transparent after standing at 50 DEG C for 7 days, without obvious precipitation, sedimentation, flocculation and the like), and is not limited to the dihydrogen phosphate generally used in similar coatings; in fact, taking the most commonly used aluminum phosphate as an example, the components contained include a certain amount of dihydrogen aluminum tripolyphosphate, dihydrogen aluminum phosphate, aluminum phosphate and the like, which can be dissolved in the acidic solution system with pH less than 2 and have good compatibility stability; the phosphates of zinc, magnesium and calcium are mainly in the form of dihydrogen phosphate; the stable existence of a plurality of phosphates is conducive to the improvement of the compactness of the coating.

[0048] When the solid content of the water-soluble metal phosphate is set to 100 mass parts, the addition amount of the water-dispersible organic resin is 20-160 mass parts, and in a further preferred embodiment, the addition amount of the water-dispersible organic resin is 20-100 parts; if the content of the water-dispersible organic resin is low, the punching performance of the formed coating is poor and the appearance uniformity is poor; within a certain range, the higher the resin content, the better the insulation, corrosion resistance and other cold working properties including the adhesion of the coating dispensing; however, if it is too high, the adhesion improvement tends to be saturated, and the thermal working properties including coating welding, heat adhesion and the like are significantly deteriorated, and the coating cost is also increased. The present application requires that the water-dispersible organic resin is in the form of water-dispersible emulsion, the main film-forming mechanism of which is mainly particle aggregation into a film, rather than cross-linking and solidification into a film, and the water-dispersible organic resin can use one or more of polyester emulsion, polyurethane emulsion, polyacrylate emulsion and polyvinyl acetate emulsion; considering the heat resistance and cost control requirements of the coating, a cationic polyurethane / polyacrylate emulsion is preferably used.

[0049] When the solid content of the water-soluble metal phosphate is set as 100 parts by mass, the amount of the adhesive function promoter added is 7-18 parts by mass, and in a further preferred embodiment, the amount of the adhesive function promoter is 10-15 parts by mass; the adhesive function promoter mainly includes the following three types of components:

[0050] (1) a soluble metal ion salt, the solid amount of which is 2-9 parts by mass, and in a preferred embodiment, the parts by mass of the solid amount of the soluble metal ion salt is 3-6 parts; wherein the soluble metal ion salt is an inorganic metal ion salt or an organic metal ion salt that can be dissolved in a water solution with pH<2.0, and specifically, the soluble metal ion salt includes at least one or more of various inorganic salts or organic salts of Fe, Cu, Mn, etc. that can be dissolved in a water solution with pH<2 and are relatively stable, such as chlorides, sulfates, nitrates or phosphates of Fe, Cu and Mn in various valence states, and organic copper lithium R2CuLi, copper acetate, ferric citrate FeC6H5O7, etc., i.e., the soluble metal ion salt is selected from one or more of chlorides of Fe, sulfates of Fe, nitrates of Fe, phosphates of Fe, chlorides of Cu, sulfates of Cu, nitrates of Cu, phosphates of Cu, chlorides of Mn, sulfates of Mn, nitrates of Mn, phosphates of Mn, organic copper lithium R2CuLi, copper acetate, ferric citrate FeC6H5O7. Although the coating containing certain organic metal salts has a relatively significant promoting effect on the curing of the adhesive (hereinafter referred to as adhesive) used in the point gluing forming process of the iron core, the raw material of the organic salt is not easy to obtain, and the compatibility and stability in the coating system are generally poor, and a chelating agent needs to be used to optimize the coating formula, therefore, the inorganic metal ion salt described above is preferably used in the present application. The larger the application amount of the inorganic metal ion salt is, the more beneficial to the curing speed and bonding strength of the adhesive, but the more deteriorated the corrosion resistance of the coating is; the deterioration degree of the inorganic ferrous dihydrogen phosphate on the corrosion resistance of the coating is relatively controllable, therefore, it can be preferentially selected, and the preparation method is as follows: high-activity Fe2O3 or Fe(OH)3 and diaphthong P2O5 or high-concentration phosphoric acid H3PO4 are selected as raw materials, the molar ratio of phosphorus / iron P2O5:Fe2O3 is set as ≥5, the reaction temperature is 200-280℃, and the impurities are removed by filtration to obtain a relatively stable ferrous dihydrogen phosphate solution.

[0051] (2) a hydrophilic nano-oxide dispersion liquid, the mass fraction of which is 1-8 parts based on the solid mass of the nano-oxide; in a preferred embodiment, the mass fraction of the hydrophilic nano-oxide dispersion liquid is 2-5 parts based on the solid mass of the nano-oxide. The nano-oxide in the hydrophilic nano-oxide dispersion liquid is composed of colloidal SiO2 and Si / Al / Ti fumed oxide, and the solid mass ratio of colloidal SiO2 to Si / Al / Ti fumed oxide ranges from (1-3) to 1. The colloidal SiO2 is in the form of a colloidal silica aqueous solution, and the average particle size D50 of the colloidal SiO2 is 5-20 nm, and in a preferred embodiment, the average particle size D50 of the colloidal SiO2 is 8-15 nm; the Si / Al / Ti fumed oxide is in the form of fumed nano-oxide particle powder produced by high-temperature flame decomposition of Si / Al / Ti raw materials, and the average particle size D50 of the Si / Al / Ti fumed oxide is 5-15 nm, so as to ensure that the Si / Al / Ti fumed oxide is put into a water-based solution and, after high-speed stirring by a suitable process, the average particle size D50 of Si / Al / Ti agglomerates (Si / Al / Ti fumed oxide exists in the form of Si / Al / Ti agglomerates after dispersion in the industrial dispersion liquid) in the industrial dispersion liquid is controlled to be 0.05-0.35 μm; the hydrophilic nano-oxide dispersion liquid thus formed contains two or more kinds of nano-oxide, and the particle size distribution thereof has a typical bimodal structure, i.e., it contains small-particle nano-level colloidal SiO2 and large-particle sub-micron-level fumed oxide agglomerates. The Si / Al / Ti raw materials and related products can be directly used as commercially available products such as .

[0052] Since the water-dispersible organic resin of the present application is used in the form of a film formed by aggregation of particles, and the small-particle colloidal SiO2 and large-particle Si / Al / Ti fumed oxide agglomerates are used in combination, the coating density is improved, and the heat resistance and corrosion resistance of the coating are improved. Furthermore, the surfaces of the nano-oxide particles in the two forms contain a large number of polar hydroxyl groups, which easily contact any type of core point gluing adhesive at the molecular level to improve the bonding speed, and the large-particle fumed nano-oxide plays a mechanical interlocking role in the cured adhesive, thereby improving the bonding strength. The greater the dosage of the hydrophilic nano-oxide, the more stable the curing effect of the adhesive, and the more beneficial to the coating density, heat resistance and corrosion resistance, but the coating punching performance is significantly deteriorated, so there is an optimal range.

[0053] (3) the balance is a high-boiling-point moisture-retaining polyol; wherein the high-boiling-point moisture-retaining polyol is a polyol with a boiling point of ≥180°C and certain moisture-retaining or moisture-absorbing properties, such as ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, butanediol, hexanediol, sorbitol, xylitol, etc. The high-boiling-point moisture-retaining polyol only needs to have certain moisture-retaining or moisture-absorbing properties. The coating containing a certain amount of high-boiling-point moisture-retaining polyol can still be kept in the cured coating to a certain extent after baking and curing, which is beneficial to the adhesion of the adhesive type with a moisture curing mechanism; meanwhile, the high-boiling-point moisture-retaining polyol can also be used as an organic additive or solvent in the coating, which will not significantly affect the main properties of the coating.

[0054] The silicon steel insulation coating prepared by the method described above is coated on a non-oriented silicon steel sheet, and then baked and cured at a sheet temperature of 200-300°C to form a film, thereby forming a silicon steel insulation coating. The thickness of the insulation coating on the surface of the silicon steel sheet is controlled to be 0.3-1.5 μm.

[0055] The silicon steel insulation coating prepared by the method described above is coated on a non-oriented silicon steel sheet, and then baked and cured at a sheet temperature of 200-300°C to form a film, thereby forming a silicon steel insulation coating. The thickness of the insulation coating on the surface of the silicon steel sheet is controlled to be 0.3-1.5 μm.

[0056] Example (I)

[0057] This example is directed to the influence of the selection and dosage of the water-dispersible organic resin on the main properties of the coating:

[0058] In this example, the water-dispersible organic resin is a water-dispersible emulsion, and its main film-forming mechanism is mainly particle aggregation into a film, because under the condition that the other ingredients in the formula are the same, the amount of the coating that is damaged and falls off at the cutout after punching is relatively small (see Figure 1 ), and the adhesion effect of the silicon steel insulation coating sheet after the core dispensing process is obviously better than that of the cross-linked and cured film-forming coating (see Figure 2 ). Of course, the more the dosage of the water-dispersible organic resin in the organic film-forming component, the better the insulation, corrosion resistance, and cold working properties of the coating, including the adhesion properties, but the thermal properties of the coating, such as welding and thermal adhesion, are obviously deteriorated, which is also not conducive to the stability and cost control of the coating, so the optimal solid amount thereof is 25-100 parts per 100 parts of the water-soluble metal phosphate (see Figure 3 , coating film thickness 0.5 μm).

[0059] Example (II)

[0060] This example is directed to the influence of the component of the adhesion function promoter on the main properties of the coating:

[0061] The soluble metal ion salts of Fe, Cu, Mn and the like selected in the embodiment can play a promoting role on the curing of the adhesive in the coating. It has been found that the Fe ion salt mainly improves the adhesive strength after the curing of the adhesive, and the Cu / Mn ion salt mainly improves the initial curing speed of the adhesive, as shown in Table 1. Figure 4

[0062] In the silicon steel insulation coating paint for core dispensing forming in the embodiment, the water-soluble metal phosphate solid amount is 100 parts, and the water-dispersible organic resin amount is 30 parts. The components and mass fractions of the adhesive function promoter are shown in Table 1. The coating formed by the above-mentioned paint is fully baked and cured at a plate temperature of 260℃, the single-side dry film thickness is controlled to be 1.0 μm, and the performance evaluation results of the finally formed coating are shown in Table 2. In Table 2, the evaluation symbols are ◎ excellent, ⊙ good, ○ general, △ deviation, and × unacceptable.

[0063]

[0064] Table 2 Performance of the coating

[0065]

[0066] It can be known from Tables 1 and 2 that:

[0067] a) For the soluble metal ion salt, the Fe ion salt should be selected preferentially, and at least one ion salt of Cu or Mn is compounded and applied, so as to simultaneously ensure the initial curing speed and the final strength of the adhesive of the obtained coating. If the addition amount is too low, the soluble metal ion salt cannot play a promoting role on the curing of the adhesive. If the addition amount is too high, it is not conducive to the corrosion resistance of the coating, and the storage stability of the paint is also affected. Therefore, the appropriate solid amount is 2-9 mass parts;

[0068] b) For the hydrophilic nano-oxide dispersion liquid, the application of the small-particle colloidal SiO2 and the large-particle Si / Al / Ti gas-phase nano-oxide is simultaneously compounded, the mass fraction is controlled to be 1-8 parts, and the solid mass ratio of the colloidal SiO2 to the Si / Al / Ti oxide particle is in the range of (1-3):1. The main performances of the coating, such as the adhesion, corrosion resistance, punching, welding and heat resistance and the like, can be considered.

[0069] c) The addition of an appropriate amount of high-boiling-point moisturizing polyol can be used as an organic auxiliary agent or solvent in the paint, and can also improve the wide adaptability of the obtained coating to various types of adhesives.

[0070] Those skilled in the art should understand that the above embodiments are only used to illustrate the present application, and are not used as a limitation on the present application. Any changes and modifications of the above embodiments within the scope of the spirit of the present application will fall within the scope of the claims of the present application.​

Claims

1. A silicon steel insulating coating for core glue forming, characterized in that: Includes the following ingredients in parts by mass: 100 parts of water-soluble metal phosphate; 20-160 parts of water-dispersible organic resin; 7-18 parts of adhesive function promoter, The water-soluble metal phosphates include one or more water-soluble phosphates of aluminum, zinc, magnesium, and calcium; The water-dispersible organic resin is selected from one or more of polyester emulsion, polyurethane emulsion, polyacrylate emulsion and polyvinyl acetate emulsion; The adhesive function promoter includes the following components in parts by mass: 2-9 parts of soluble metal ion salt; 1-8 parts of hydrophilic nano-oxide dispersion; The balance is high boiling point moisturizing polyol; Wherein, the hydrophilic nano-oxide dispersion is calculated based on the solid mass of the nano-oxide. The soluble metal ion salt is an inorganic metal ion salt or an organic metal ion salt that can be dissolved in an aqueous solution with a pH value less than 2.0; The soluble metal ion salt is selected from one or more of Fe chloride, Fe sulfate, Fe nitrate, Fe phosphate, Cu chloride, Cu sulfate, Cu nitrate, Cu phosphate, Mn chloride, Mn sulfate, Mn nitrate, Mn phosphate, organic copper lithium, copper acetate, and ferric citrate FeC6H5O7; The nano-oxides in the hydrophilic nano-oxide dispersion are composed of colloidal SiO2 and Si / Al / Ti vapor-phase oxides; the colloidal SiO2 is supplied in the form of a colloidal silica aqueous solution, and has an average particle size D50 of 5 to 20 nm; the Si / Al / Ti vapor-phase oxide is supplied in the form of vapor-phase nano-oxide particle powder generated by high-temperature flame decomposition of Si / Al / Ti raw materials, and has an average particle size D50 of 5 to 15 nm; The boiling point of the high-boiling-point moisturizing polyol is ≥180°C; The high boiling point moisturizing polyol is selected from one or more of diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, hexylene glycol, sorbitol, and xylitol. In the hydrophilic nano-oxide dispersion, the average particle size D50 of agglomerates formed after the Si / Al / Ti vapor-phase oxide is dispersed is 0.05 to 0.35 μm.

2. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The water-soluble aluminum phosphate is selected from one or more of aluminum dihydrogen phosphate, aluminum dihydrogen tripolyphosphate, aluminum monohydrogen phosphate, and aluminum phosphate.

3. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The mass fraction of the water-dispersible organic resin is 25 to 100 parts.

4. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The water-dispersible organic resin adopts a composite emulsion of cationic polyurethane emulsion and polyacrylate emulsion.

5. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The mass fraction of the adhesive function promoter is 10 to 15 parts.

6. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The mass fraction of the soluble metal ion salt is 3 to 6 parts.

7. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The hydrophilic nano-oxide dispersion has a mass fraction of 2 to 5 parts based on the solid mass of the nano-oxide.

8. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The solid mass ratio of the colloidal SiO2 to the Si / Al / Ti gas phase oxide particles is 1 to 3:

1.

9. The silicon steel insulating coating material for core glue forming according to claim 1, characterized in that: The average particle size D50 of the colloidal SiO2 is 8 to 15 nm.

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