▎ 摘　　要

NOVELTY - A heat conductive particle filling fiber comprises heat conductive particles and a resin having weight average molecular weight of 30000-300000. The heat conductive particles comprise thermally conductive particles (X) having particle size of 10-900 nm. The thermally conductive particles (X) comprise 5-50 %mass particles (X100) having particle size of 100 nm or more. USE - Heat conductive particle filling fiber used in resin composition (claimed) used as thermal radiation material and heat exchange material for electronic devices. Uses include but are not limited to high-performance filter, battery separator, electromagnetic wave shielding material, artificial leather, cell culture substrate, integrated circuit chip, organic electroluminescent, and solar cells. ADVANTAGE - The fiber has excellent thermal conductivity and workability at the time of mixing with resin. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of heat conductive particle filling fiber, which involves mixing a heat conductive particles (X1) having average particle diameter of less than 100 nm, a heat conductive particles (X2) having average particle diameter of 100-900 nm, and the resin; (2) resin composition, which comprises the heat conductive particle filling fiber, and a matrix resin; and (3) manufacture of resin composition, which involves manufacturing the heat conductive particle filling fiber, blending the heat conductive particle filling fiber with the resin, and spinning by an electrospinning method using a polymer solution containing the resin, the heat conductive particles (X1) and the thermally conductive particles (X2) and a solvent.