| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface treatment liquid for obtaining an electrical steel plate with an insulation coating that has excellent corrosion resistance even when the insulation coating contains no chromium compound, and can obtain excellent coating appearance, water resistance, and tension pad resistance and further obtain high inter-layer resistance.SOLUTION: A surface treatment liquid for an electrical steel plate contains 0.1-6.5 mass% of predetermined alkoxysilane (A), 1-10 mass% of a silane coupling agent (B) having an epoxy group, 15-60 mass% of oxide fine particles (C) of 300 nm or less in average particle size for the content of the silane coupling agent, and 0.3-5.0 mass% of carboxylic acid (D), and is adjusted so that pH is 5.0-7.0 and the rate of solid content is 3-15 mass%. |
