| 摘要 |
PROBLEM TO BE SOLVED: To provide a laminated sheet having a good tracking resistance. SOLUTION: This prepreg is obtained by impregnating a paper substrate with a varnish obtained by dissolving a resin composition consisting essentially of a water-soluble and hardenable resin in pure water having <=1,000μS/m electric conductivity, or a mixed solvent of the pure water having <=1,000μS/m electric conductivity with methanol, drying the impregnated paper substrate, and further impregnating the dried paper substrate with a varnish obtained by dissolving a resin composition consisting essentially of a tung oil-modified phenol resin in an organic solvent, and drying the impregnated paper substrate. The laminated sheet is obtained by heating and pressing the prescribed number of sheets of the prepreg.
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