Disclosed is an excellent emulsion stability, storage stability, and has low skin irritation, no stickiness at the time of application, can be fresh, non-powdery texture and frictional feeling, and even excellent in lasting effect of scent to provide an oil-in-water emulsion composition was emulsified with a core type microgel emulsifier and the emulsifier - novel coronavirus that used to produce an oil-in-water emulsion composition. A polyethylene oxide macromonomers, and a hydrophobic monomer, corona made of the resulting copolymer by polymerizing and crosslinking monomers under certain conditions - the core type microgel emulsifiers and the corona - core type microgel emulsifiers and is an oil-in-water emulsion composition characterized in that it was emulsified by using the emulsifier. [Selection Figure] Figure 1【課題】優れた乳化安定性、経時安定性、低皮膚刺激性を有し、塗布時のべたつきがなく、みずみずしくて、粉っぽさやきしみ感がなく、さらには香りの持続効果にも優れた水中油型乳化組成物を製造するために使用する新規なコロナ-コア型ミクロゲル乳化剤及び当該乳化剤で乳化した水中油型乳化組成物を提供すること。【解決手段】ポリエチレンオキサイドマクロモノマーと、疎水性モノマーと、架橋性モノマーとを特定の条件下で重合して得られる共重合体からなるコロナ-コア型ミクロゲル乳化剤及び当該コロナ-コア型ミクロゲル乳化剤及び当該乳化剤を使用して乳化したことを特徴とする水中油型乳化組成物である。【選択図】図1
