| 摘要 |
<p>The present invention relates to a nonoriented electrical steel sheet coated on both surfaces with a cured insulative coating for providing a high level of surface r esistivity to minimize interlaminar power losses. The cured insulative coating on the steel sh eet includes, based upon 100 parts by dry weight, 20-60 parts of aluminum phosphate, 20-70 parts of at least one inorganic particulate silicate and 10-25 parts of an acryl ic resin. The cured coating is formed from an acid aqueous suspension that may include up to 1 part by weight of a water-soluble organic solvent per each part of the resin. The aqueou s suspension has a pH of about 2-2.5, a silicate particle size of 0.3-60 .mu.m, a resin particle size of less than 1 .mu.m, less than about 0.5 wt.% unreacted phosphoric acid an d a specific gravity of about 1.0-1.3. The silicate may be one or more from the group consist ing of aluminum silicate, aluminum potassium silicate and magnesium silicate. After cur ing, the coating has a thickness on each sheet surface of 0.5-8 .mu.m. The insulative coa ted nonoriented electrical steels may be used to minimize power losses in laminated magnetic cores of motors, generators, transformers, and other electrical equipment.</p> |
