| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulating sheet having a resin film excellent in heat resistance, withstand voltage characteristics and surface characteristics as a dielectric film.SOLUTION: An insulating sheet has a layer formed of a dielectric film. The dielectric film is obtained by stretching an unstretched film using a hydrogenated crystalline dicyclopentadiene ring-opened polymer, and then heating the resultant film. When a resin film is heated at a softening point of 250-320°C and a temperature of 200°C for 10 minutes, the resin film has a thermal shrinkage rate of 0.01-5.0%, surface roughness of 10-100 nm, and dielectric breakdown voltage of 300-1,000 kV/mm.SELECTED DRAWING: None |
