THERMOSETTING RESIN COMPOSITION, RESIN SHEET, PREPREG AND LAMINATE SHEET

PROBLEM TO BE SOLVED: To provide a resin composition high in heat-conductivity and excellent in insulation properties at high temperature, a resin sheet, a prepreg and a laminate sheet.SOLUTION: There is provided a thermosetting resin composition containing: a polyfunctional epoxy resin monomer; a polyfunctional amine compound; an inorganic filler (A) which is an aggregate of primary particles and has an average particle diameter d1 of 10 μm to 70 μm; and an inorganic filler (B) containing an inorganic filler(b) having an average particle diameter d3 of particle unit of 1 μm or more and less than 10 μm and an inorganic filler (c) having an average particle diameter d4 of 0.1 μm or more and less than 1 μm. A volume ratio of the (b) : the (c) is 90:10 to 70:30. A percentage content of the (A) to a total solid content is 10 to 55 vol.%, and a percentage content of (B) to the total solid content is 10 to 55 vol.%. The total percentage content of the (A) and the (B) is 30 to 80 vol.%. 【課題】熱伝導率が高く、且つ高温時の絶縁性に優れる樹脂組成物、樹脂シート、プリプレグ及び積層板を提供する。【解決手段】多官能エポキシ樹脂モノマーと、多官能アミン化合物と、一次粒子の凝集体であって平均粒径ｄ１が１０μｍ以上７０μｍ以下の無機充填材（Ａ）と、粒子単体の平均粒径ｄ３が１μｍ以上１０μｍ未満の無機充填材（ｂ）及び平均粒径ｄ４が０．１μｍ以上１μｍ未満の無機充填材（ｃ）を含む無機充填材（Ｂ）と、を含み、上記（ｂ）と（ｃ）との体積比が９０：１０〜７０：３０であり、総固形分に対して、上記（Ａ）の含有率が１０〜５５体積％であり、上記（Ｂ）の含有率が１０〜５５体積％であり、上記（Ａ）及び（Ｂ）の総含有率が３０〜８０体積％である熱硬化性樹脂組成物を提供する。【選択図】なし