High-thermal-conductivity corrosion-resistant electrical steel self-bonding coating and preparation method thereof

Abstract

The invention discloses a high-thermal-conductivity corrosion-resistant electrical steel self-bonding coating and a preparation method thereof. The self-adhesive coating comprises the following components in percentage by mass: 25%-35% of bisphenol A type epoxy resin, 4%-8% of novolac epoxy resin, 0.2%-0.5% of isooctyl phosphate, 5%-10% of propylene glycol monomethyl ether, 5%-8% of an emulsifier, 1%-3% of dimethylaminoethoxy trioxaborooctacycle, 0.5%-2% of ammonium blocked Lewis acid salt, 3%-12% of boron nitride fiber, 0.4%-1.0% of alumina fiber, 0.2%-0.3% of a grinding aid and the balance of pure water. An activated self-adhesive coating formed after the self-adhesive coating is subjected to primary curing remarkably improves the corrosion resistance to an electrical steel substrate, the self-adhesive coating has high heat conductivity, and the operation difficulty of primary curing and secondary hot-pressing curing process conditions is remarkably reduced. The preparation method of the self-adhesive coating is easy to operate and high in implementation feasibility.

Description

technical field [0001] The invention relates to the technical field of insulating coatings for metal surfaces, in particular to a self-adhesive coating for high thermal conductivity and corrosion-resistant electrical steel and a preparation method thereof. Background technique [0002] Electrical steel sheets, also known as silicon steel sheets, are mainly used in various motor cores. In the existing motor manufacturing process, the electrical steel is usually welded, bolted or riveted to fasten the motor core after being punched and laminated, but the above connection methods may have the following problems: (1) Or the riveting will lead to the deterioration of the magnetic performance of the iron core, which will affect the operating efficiency of the motor; (2) only a part of the iron core is fastened, and it is easy to generate noise during magnetization resonance; (3) only part of the iron core is fixed, which cannot be applied to The working conditions with high faste...

AI Technical Summary

Problems solved by technology

In the existing motor manufacturing process, the electrical steel is usually welded, bolted or riveted to fasten the motor core after being punched and laminated, but the above connection methods may have the following problems: (1) Or the riveting will lead to the deterioration of the magnetic performance of the iron core, which will affect the operating efficiency of the motor; (2) only a part of the iron core is fastened, and it is easy to generate noise during magnetization resonance; (3) only part of the iron core is fixed, which cannot be applied to It is not suitable for micro motors in the working conditions with high fastening requirements

[0011] 1. In the activated state (semi-cured state) after primary curing, the corrosion resistance of the coating is poor; under the damp heat test conditions (50°C, 95% relative humidity, 72 hours), the corrosion area reaches more than 20%;

[0012] 2. The thermal conductivity of the all-organic coating or the self-adhesive coating doped with inorganic nano-powder is relatively low. After the laminated iron core of the motor is made, the heat dissipation of the iron core will be reduced due to the poor thermal conductivity of the coating. Poor condition, which limits the application of self-adhesive coatings to some extent;

[0013] 3. Most of the curing agents of existing self-adhesive coatings use dicyandiamide, and there are also a small amount of systems with imidazole, amino resin or isocyanate. Because dicyandiamide needs a higher temperature (above 150°C) to cure epoxy resin in the system ), it is difficult to control once curing (semi-cured state) in production

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