Silicon steel sheet self-adhesive glue as well as preparation method and application thereof

Abstract

The invention relates to silicon steel sheet self-adhesive glue and a preparation method and application thereof.The silicon steel sheet self-adhesive glue comprises epoxy resin, an emulsifier, a curing agent, filler and a solvent, the epoxy resin is bisphenol A type epoxy resin and polyurethane modified epoxy resin, the epoxy value of the bisphenol A type epoxy resin is 0.1-0.2 mol / 100g, and the epoxy value of the polyurethane modified epoxy resin is 0.1-0.2 mol / 100g. The mass ratio of the bisphenol A type epoxy resin to the polyurethane modified epoxy resin is 1: (0.01-0.03). The silicon steel sheet self-adhesive glue is high in peel strength, good in storage stability, high in heat resistance grade and good in aging resistance, can meet the strict working condition requirements of motor silicon steel sheet coating, can realize uniform film formation of a coating within a short time, and is convenient to use, lower in energy consumption and wide in application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical insulation, and particularly relates to a self-adhesive glue for silicon steel sheets, a preparation method thereof, and an application thereof. Background Art

[0002] Most electrical steel sheets are assembled into iron cores by welding, bolt connection, self-latching or riveting methods. However, whether it is welding, bolt connection, self-latching or riveting fixing methods, they are all point-fixed locally on the chips, and the connection force is not high, making it difficult to meet the situation with high requirements for fastening strength. In addition, welding and riveting methods are not applicable to many micro-motors. In contrast, the self-adhesive coating bonds the silicon steel sheets together by a "surface" fixing method, significantly improving the connection strength and having a wider applicability.

[0003] However, there are still many problems in the actual application of self-adhesive glue, which seriously restrict its large-scale production and application. For example, its curing time is long and the curing temperature is high, which not only increases the production cost but also reduces the production efficiency. In the B stage (the stage where the self-adhesive glue transitions from liquid to solid), the surface of the coating is prone to adhesion after surface drying, bringing great inconvenience to transportation and post-curing. In addition, the powder dispersibility of the self-adhesive glue is poor, resulting in a decrease in strength after impregnating with insulating paint and easy cracking. These problems not only affect the subsequent stamping process but may also have an adverse effect on the post-curing effect in the C stage (the state after the self-adhesive glue is completely cured), further restricting its application prospects in large-scale production. Summary of the Invention

[0004] The purpose of the present invention is to provide a self-adhesive glue for silicon steel sheets that can be cured in a short time, has good stability and excellent mechanical strength, as well as a preparation method and an application thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] On the one hand, the present invention provides a self-adhesive glue for silicon steel sheets, which includes epoxy resin, emulsifier, curing agent, filler and solvent. The epoxy resin is a compound of bisphenol A type epoxy resin and polyurethane-modified epoxy resin. The epoxy value of the bisphenol A type epoxy resin is 0.1 - 0.2 mol / 100g. The mass ratio of the bisphenol A type epoxy resin to the polyurethane-modified epoxy resin is 1:(0.01 - 0.03). The mass ratio of the epoxy resin to the emulsifier is 1:(0.005 - 0.015). The mass ratio of the epoxy resin to the curing agent is 1:(0.001 - 0.05). The mass ratio of the epoxy resin to the filler is 1:(0.001 - 0.05).

[0007] Preferably, the mass ratio of the bisphenol A epoxy resin to the polyurethane-modified epoxy resin is 1:(0.015 - 0.025), such as 1:0.015, 1:0.018, 1:0.02, 1:0.023, 1:0.025.

[0008] Preferably, the curing agent is selected from one or more of blocked isocyanates and dicyandiamide.

[0009] More preferably, the curing agent is a blocked isocyanate.

[0010] In some embodiments, the blocked isocyanate is obtained by mixing an MDI-type prepolymer, caprolactam, and organotin in a mass ratio of 1:(0.01 - 0.5):(0.001 - 0.03) and reacting at 120 - 140 °C. The blocked isocyanate prepared in the present invention can accurately release the -NCO group at a specific high temperature (180 - 220 °C) to form a dense cross-linked network, thereby effectively inhibiting the pre-reaction and improving the storage stability of the silicon steel sheet self-adhesive.

[0011] More preferably, the reaction time is 2 - 4 h.

[0012] Preferably, the emulsifier is selected from one or more of sodium dodecyl sulfate, polyethylene oxide, and polyethylene glycol.

[0013] Preferably, the filler is silica.

[0014] More preferably, the filler is fumed silica.

[0015] Preferably, the solvent is selected from one or more of propylene glycol monomethyl ether, N,N-dimethylformamide, and water.

[0016] Preferably, the silicon steel sheet self-adhesive further comprises additives, and the additives include one or more of a promoter, a leveling agent, an adhesion promoter, and an organosilicon defoamer.

[0017] In some embodiments, the promoter is a tertiary amine promoter.

[0018] More preferably, the mass ratio of the promoter to the epoxy resin is (0.001 - 0.005):1.

[0019] In some embodiments, the leveling agent is a polyether silicone copolymer.

[0020] More preferably, the mass ratio of the leveling agent to the epoxy resin is (0.001 - 0.005):1.

[0021] In some embodiments, the adhesion promoter is a macromolecular polyether-modified acrylate.

[0022] Further preferably, the mass ratio of the adhesion promoter to the epoxy resin is (0.001 - 0.008):1.

[0023] In some embodiments, the mass ratio of the silicone defoamer to the epoxy resin is (0.001 - 0.005):1.

[0024] Preferably, the solid content of the silicon steel sheet self - adhesive is 40 - 50%.

[0025] The second aspect of the present invention is to provide a preparation method of the silicon steel sheet self - adhesive as described above. The preparation method includes the following steps:

[0026] (1) Mix bisphenol A epoxy resin, polyurethane - modified epoxy resin, emulsifier, curing agent and solvent, and make an emulsion through stirring and emulsification;

[0027] (2) Mix the emulsion with fillers and grind them, and selectively mix the ground mixture system with additives to obtain the silicon steel sheet self - adhesive.

[0028] Preferably, after mixing the emulsifier with the solvent, then mix with the epoxy resin, the polyurethane - modified epoxy resin, and the curing agent.

[0029] Further preferably, the mass ratio of the emulsifier to the solvent in the feeding is (0.005 - 0.015):1.

[0030] Preferably, the stirring speed in step (1) is 2000 - 3000 r / min.

[0031] Further preferably, the stirring time in step (1) is 10 - 30 min.

[0032] Preferably, an ultrasonic emulsification device is used for the emulsification.

[0033] Further preferably, the emulsification temperature is 40 - 60 °C and the time is 5 - 20 min.

[0034] Preferably, the grinding time is 20 - 40 min.

[0035] Preferably, when mixing the ground mixture system with the additives, a high - speed stirrer is used for stirring.

[0036] Further preferably, control the stirring speed of the high - speed stirrer to be 2000 - 3000 r / min and the time to be 20 - 40 min.

[0037] The third aspect of the present invention is to provide an application of the self - adhesive glue for silicon steel sheets as described above. The application includes coating the self - adhesive glue for silicon steel sheets onto the silicon steel sheets to form a coating, and then performing surface drying and curing.

[0038] Preferably, the thickness of the coating is 2 - 10 μm.

[0039] Preferably, the temperature for curing is 150 - 250 °C, the time is 1 - 60 min, and the pressure is 2 - 5 MPa.

[0040] More preferably, the temperature for curing is 160 - 200 °C, the time is 2 - 60 min, and the pressure is 4 - 5 MPa.

[0041] Even more preferably, the temperature for curing is 190 - 200 °C, the time is 2 - 5 min, and the pressure is 4 - 5 MPa.

[0042] Preferably, the temperature for surface drying is 160 - 200 °C, and the time is 0.5 - 5 min.

[0043] More preferably, the temperature for surface drying is 180 - 200 °C, and the time is 0.5 - 2 min.

[0044] The fourth aspect of the present invention is to provide a self - adhesive coating for silicon steel sheets, which is formed by the above - mentioned self - adhesive glue for silicon steel sheets.

[0045] Preferably, the thickness of the self - adhesive coating is 2 - 10 μm.

[0046] Preferably, the self - adhesive glue for silicon steel sheets is surface - dried and cured to form the self - adhesive coating for silicon steel sheets. The surface - drying and curing processes are as above and will not be repeated here.

[0047] Due to the application of the above - mentioned technical solutions, the present invention has the following advantages compared with the prior art:

[0048] The self - adhesive glue for silicon steel sheets of the present invention has high peel strength, good storage stability, high heat - resistance grade, and good aging - resistance performance. It can meet the stringent working conditions requirements for the coating of motor silicon steel sheets, and can form a uniform film in a relatively short time. It is convenient to use, has lower energy consumption, and has a wide application prospect. Detailed Embodiments

[0049] The present invention will be further described below in conjunction with embodiments. However, the present invention is not limited to the following embodiments. The implementation conditions adopted in the embodiments can be further adjusted according to different requirements of specific uses. The implementation conditions not specified are the conventional conditions in the industry. The technical features involved in each implementation manner of the present invention can be combined with each other as long as they do not conflict with each other.

[0050] Unless otherwise specified, the raw materials and instruments involved in the following examples are commercially available products or can be prepared by referring to existing methods. The bisphenol A resin was purchased from Baling Petrochemical, with the trade name E20; the polyurethane-modified resin was purchased from Zhuzhou Shilin, with the trade name SL3403; the tertiary amine accelerator was triethanolamine from Dow; the leveling agent was TEGO Glide 450 from Degussa; the adhesion promoter was BYK-3560 from BYK; the silicone defoamer was DAPRO DF 696 from Elementis.

[0051] In the following text,

[0052] The blocked isocyanate was self-made. The preparation method included adding MDI prepolymer (purchased from Wanhua Chemical, model PM200), caprolactam and organotin (CAS No.: 167693-36-9) into a three-necked flask according to the mass ratio of 1:0.1:0.005, heating to 130 °C with stirring, keeping warm for 3 h, and then evacuating to obtain it.

[0053] Example 1

[0054] 50 g of preheated E20 resin and 1 g of polyurethane-modified resin were slowly added to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass ratio of 10:1. At the same time, 0.5 g of blocked isocyanate was added. A high-speed stirrer was used to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, it was transferred to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0055] 0.5 g of gaseous silica was added to the epoxy emulsion and ground. After grinding for 30 min, 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer were successively added to the emulsion. A high-speed stirrer was used to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0056] The self-adhesive coating emulsion was coated on the silicon steel sheet, and the coating thickness was controlled at 2 - 10 μm. It was surface-dried (temperature: 180 °C, time: 1 min) and cured (temperature: 200 °C, pressure: 5 MPa, curing time: 2 min).

[0057] Example 2

[0058] Slowly add 50 g of preheated E20 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0059] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0060] Coat the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and perform surface drying (temperature 180 °C, time 1 min), curing (temperature 180 °C, pressure 5 MPa, curing time 20 min).

[0061] Example 3

[0062] Slowly add 50 g of preheated E20 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0063] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0064] Coat the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and perform surface drying (temperature 180 °C, time 1 min), curing (temperature 160 °C, pressure 5 MPa, curing time 30 min).

[0065] Example 4

[0066] Slowly add 50 g of preheated E20 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0067] Add 0.5 g of gaseous silica to the epoxy emulsion and grind for 30 min to obtain a self-adhesive coating emulsion.

[0068] Apply the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and perform surface drying (temperature 180 °C, time 5 min), curing (temperature 200 °C, pressure 5 MPa, curing time 2 min).

[0069] Example 5

[0070] Slowly add 50 g of preheated E20 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 5 g of a dicyandiamide DMF solution with a mass content of 14%. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0071] Add 0.5 g of gaseous silica to the epoxy emulsion and grind. After grinding for 30 min, sequentially add 0.1 g of a tertiary amine accelerator, 0.1 g of a leveling agent, 0.2 g of an adhesion promoter, and 0.1 g of an organosilicon defoamer to the emulsion, and use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0072] Apply the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and perform surface drying (temperature 180 °C, time 1 min), curing (temperature 200 °C, pressure 5 MPa, curing time 2 min).

[0073] Comparative Example 1

[0074] Slowly add 50 g of preheated E20 resin to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass ratio of 10:1. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0075] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0076] Coat the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and conduct surface drying (temperature 180 °C, time 1 min), curing (temperature 200 °C, pressure 5 MPa, curing time 2 min).

[0077] Comparative Example 2

[0078] Slowly add 50 g of preheated E20 resin and 2 g of polyurethane-modified resin to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass ratio of 10:1. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0079] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0080] Coat the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, and conduct surface drying (temperature 180 °C, time 1 min), curing (temperature 200 °C, pressure 5 MPa, curing time 2 min).

[0081] Comparative Example 3

[0082] Slowly add 30 g of preheated E20 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0083] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0084] Apply the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, perform surface drying (temperature: 180 °C, time: 1 min), and curing (temperature: 200 °C, pressure: 5 MPa, curing time: 2 min).

[0085] Comparative Example 4

[0086] Slowly add 50 g of preheated E44 resin and 1 g of polyurethane-modified resin in a mass ratio of 10:1 to a propylene glycol methyl ether solution containing 10% sodium dodecyl sulfate by mass. At the same time, add 0.5 g of blocked isocyanate. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min. After stirring evenly, transfer it to an ultrasonic emulsification device for auxiliary emulsification at a temperature of 50 °C for 10 min to further refine the emulsion particles and obtain an epoxy emulsion.

[0087] Add 0.5 g of gaseous silica to the epoxy emulsion and grind it. After grinding for 30 min, sequentially add 0.1 g of tertiary amine accelerator, 0.1 g of leveling agent, 0.2 g of adhesion promoter, and 0.1 g of silicone defoamer to the emulsion. Use a high-speed stirrer to stir at a stirring speed of 2000 - 3000 r / min for 30 min to obtain a self-adhesive coating emulsion.

[0088] Apply the self-adhesive coating emulsion on the silicon steel sheet, control the coating thickness at 2 - 10 μm, perform surface drying (temperature: 180 °C, time: 1 min), and curing (temperature: 200 °C, pressure: 5 MPa, curing time: 2 min).

[0089] Performance test:

[0090] 1. Viscosity test: Use a No. 4 Ford cup and test at 23 ± 1 °C.

[0091] 2. Solid content: Take 1 - 2 g and place it in an aluminum foil box, bake at 130 °C for 2 h, and calculate the percentage of the remaining mass.

[0092] 3. Adhesion test: Test according to GB / T 9286 - 2021 "Cross - cut test for paints and varnishes", observe the number of squares that peel off. The smaller the value, the better the adhesion.

[0093] 4. Peel strength test: The test specimens are tested according to GB / T 7122 - 1996 "Determination of peel strength of high - strength adhesives - Floating roller method".

[0094] 5. Storage stability test: Store at 40 °C for 1 month, test the peel strength, compare the reduction ratio calculated from the initial peel strength of the formula. The smaller the value, the better the storage stability.

[0095] 6. Heat - resistance grade test: Test according to JB / T 1544 - 2015 "Rapid thermal aging test method for electrical insulation impregnating varnishes and varnished cloths - Thermal - key - slope method".

[0096] 7. Thermal aging: Age in an oven at 165 °C for 15 h, and test the peel strength according to GB / T 7122 - 1996 "Determination of peel strength of high - strength adhesives - Floating roller method".

[0097] 8. Impregnated paint thermal aging: Impregnate with JF - 9965 epoxy paint for 1 h, age in an oven at 165 °C for 20 h, and then test the peel strength according to GB / T 7122 - 1996 "Determination of peel strength of high - strength adhesives - Floating roller method".

[0098] 9. Shelf life: Prepare 100 g of self - adhesive emulsion for each, store it in a sealed manner in a light - proof environment at 0 °C and 40 °C. Stir evenly every 15 d and then test the peel strength. If the strength attenuation is ≥20%, it is considered expired.

[0099] Table 1 Properties of water - based silicon steel sheet self - adhesive

[0100]

[0101] By comparing Example 1 with Comparative Examples 1 to 3, it is found that compared with Comparative Example 1 using a single epoxy resin as the matrix, through the compounding of bisphenol A - type epoxy resin and polyurethane - modified epoxy resin, the adhesion, peel strength, and heat - resistance grade of the self - adhesive can be effectively improved, but it may also cause deterioration of storage stability and aging resistance (such as Comparative Example 2). The inventor further optimized the ratio of bisphenol A - type epoxy resin and polyurethane - modified epoxy resin, significantly improving the storage stability and aging resistance of the self - adhesive.

[0102] By comparing Example 1 and Comparative Example 4, it is found that the epoxy value of bisphenol A epoxy resin also affects the performance of the self-adhesive glue. When the epoxy value is too large (such as in Comparative Example 4, the epoxy value is 0.41 - 0.47 mol / 100g), the epoxy resin has high hardness and poor toughness, the self-adhesive glue coating is brittle, and the bonding performance is poor.

[0103] By comparing Example 1 and Example 4, it is found that the addition of additives helps to improve the performance of the self-adhesive glue, especially the adhesion, which can effectively prevent the subsequent adhesion between silicon steel sheets, facilitating transportation and post-curing.

[0104] By comparing Example 1 and Example 5, it is found that compared with using dicyandiamide as a promoter (Example 5), using the self-made blocked isocyanate can improve the performance of the self-adhesive glue to a greater extent.

[0105] As can be seen from Example 1, the self-adhesive glue of the present invention can achieve uniform film formation with a coating thickness of 2 - 10 μm under the short-time curing condition of 200°C / 2 min, with high efficiency, low energy consumption, and more excellent performance.

[0106] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A silicon steel sheet self-adhesive adhesive, characterized in that: The silicon steel sheet self-adhesive glue includes epoxy resin, emulsifier, curing agent, filler and solvent, the epoxy resin is bisphenol A epoxy resin and polyurethane modified epoxy resin, the epoxy value of the bisphenol A epoxy resin is 0.1-0.2 mol / 100g, the mass ratio of the bisphenol A epoxy resin to the polyurethane modified epoxy resin is 1:(0.01-0.03), the mass ratio of the epoxy resin to the emulsifier is 1:(0.005-0.015), the mass ratio of the epoxy resin to the curing agent is 1:(0.001-0.05), and the mass ratio of the epoxy resin to the filler is 1:(0.001-0.05).

2. The silicon steel sheet self-adhesive adhesive according to claim 1, characterized in that: The curing agent is selected from one or more of blocked isocyanate and dicyandiamide.

3. The silicon steel sheet self-adhesive adhesive according to claim 2, characterized in that: The blocked isocyanate is obtained by mixing MDI prepolymer, caprolactam and organic tin in a mass ratio of 1: (0.01-0.5): (0.001-0.03) and reacting at 120-140°C.

4. The silicon steel sheet self-adhesive adhesive according to claim 1, characterized in that: The emulsifier is selected from one or more of sodium lauryl sulfate, polyethylene oxide, and polyethylene glycol; and / or, The filler is silicon dioxide; and / or, The solvent is selected from one or more of propylene glycol methyl ether, N,N-dimethylformamide and water.

5. The silicon steel sheet self-adhesive adhesive according to claim 1, characterized in that: The silicon steel sheet self-adhesive glue also includes an auxiliary agent, and the auxiliary agent includes one or more of an accelerator, a leveling agent, an adhesion promoter, and an organic silicon defoaming agent.

6. The silicon steel sheet self-adhesive adhesive according to claim 5, characterized in that: The accelerator is a tertiary amine accelerator, and the mass ratio of the accelerator to the epoxy resin is (0.001-0.005):1; and / or, The leveling agent is a polyether siloxane copolymer, and the mass ratio of the leveling agent to the epoxy resin is (0.001-0.005):1; and / or, The adhesion promoter is a macromolecular polyether modified acrylate, and the mass ratio of the adhesion promoter to the epoxy resin is (0.001-0.008):1; and / or, The mass ratio of the organosilicon defoamer to the epoxy resin is (0.001-0.005):

1.

7. The method for preparing the silicon steel sheet self-adhesive adhesive according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: (1) mixing epoxy resin, emulsifier, curing agent and solvent, stirring and emulsifying to form an emulsion; (2) The latex and the filler are mixed and ground, and the ground mixed system is selectively mixed with an auxiliary agent to obtain the silicon steel sheet self-adhesive glue.

8. The use of the silicon steel sheet self-adhesive adhesive according to any one of claims 1 to 6, characterized in that: The application includes applying the silicon steel sheet self-adhesive glue onto the silicon steel sheet to form a coating, and then performing surface drying and curing.

9. The use of the silicon steel sheet self-adhesive adhesive according to claim 8, characterized in that: The coating has a thickness of 2 to 10 μm.

10. The use of the silicon steel sheet self-adhesive adhesive according to claim 8, characterized in that: The curing temperature is 150-250°C, the curing time is 1-60 min, and the curing pressure is 2-5 MPa; and / or, The surface drying temperature is 160-200° C. and the time is 0.5-5 min.

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