| 摘要 |
PROBLEM TO BE SOLVED: To provide a resin composition having excellent electrical insulation properties and thermal conductivity in a thickness direction.SOLUTION: Hexagonal boron nitride powder (B) in a resin composition contains aggregated particles formed by aggregating primary particles of hexagonal boron nitride, and a particle diameter distribution curve thereof has one initial maximum peak in a range of a particle diameter of more than 1 μm and 500 μm or less. The hexagonal boron nitride powder has such properties that when being subjected to ultrasonic irradiation treatment, the particle diameter distribution curve changes and becomes a particle diameter distribution curve satisfying all of following three conditions: (Condition 1) the particle diameter distribution curve has a first maximum peak in a range of a particle diameter of 1 μm or more and 20 μm or less; (Condition 2) the particle diameter distribution curve has a second maximum peak which is in a range of a particle diameter of more than 1 μm and 350 μm or less, and in a larger particle diameter than the first maximum peak and a smaller particle diameter than the initial maximum peak; and (Condition 3) a ratio [height of the first maximum peak]/[height of the second maximum peak] of a height of the first maximum peak to a height of the second maximum peak is 0.1 or more and 8.0 or less.SELECTED DRAWING: None |
