PROBLEM TO BE SOLVED: To provide zinc oxide particles having a comparatively large particle size and high crystallinity, and to provide a method for simply producing the same.SOLUTION: A particle size of zinc oxide has a median diameter R measured by a laser diffraction/scattering method of 10 μm or more and has an average crystallite diameter of r determined by powder X-ray diffractometry of 0.06 μm or more. A particle shape is preferably a hexagonal pillar shape or a substantially hexagonal shape. The zinc oxide particles are excellent in thermal conductivity and have good filling property, and can be formed into a heat dissipation composition having high thermal conductivity.SELECTED DRAWING: Figure 4【課題】比較的粒子径が大きく、結晶性の高い酸化亜鉛粒子及びそれを簡便に製造する方法を提供する。【解決手段】酸化亜鉛の粒子径は、レーザー回折／散乱法で測定したメジアン径Ｒが１０μｍ以上であり、粉末Ｘ線回折法で求めた平均結晶子径ｒが０．０６μｍ以上である。粒子形状は六角柱状あるいは略六角柱状が好ましい。このような酸化亜鉛粒子は、熱伝導性に優れ、充填性が良好であるため、熱伝導率の高い放熱性組成物とすることができる。【選択図】図４
