PROBLEM TO BE SOLVED: To provide a method for inhibiting syneresis in an oil-in-water emulsion composition containing a metal oxide such as zinc oxide or titanium oxide, a syneresis inhibitor for the composition, and the oil-in-water emulsion composition containing the inhibitor.SOLUTION: The method for inhibiting syneresis in an oil-in-water emulsion composition containing an metal oxide comprises compounding of a silicic anhydride (particularly a hydrophilic silicic anhydride having an average primary particle size of 0.001-0.5 &mum) with the composition. The syneresis inhibitor for the oil-in-water emulsion composition containing an metal oxide comprises the silicic anhydride. The oil-in-water emulsion composition contains a metal oxide and the silicic anhydride as the syneresis inhibitor.COPYRIGHT: (C)2010,JPO&INPIT【課題】酸化亜鉛や酸化チタンなどの金属酸化物を含有する水中油型乳化組成物の離液(シネレシス)の抑制方法、該組成物の離液抑制剤および該抑制剤を含有する水中油型乳化組成物を提供する。【解決手段】無水ケイ酸(特に、平均一次粒子径0.001~0.5μmの親水性無水ケイ酸)を配合することにより、金属酸化物を含有する水中油型乳化組成物の離液を抑制する方法、該無水ケイ酸を含有してなる金属酸化物を含有する水中油型乳化組成物の離液抑制剤、および金属酸化物ならびに離液抑制剤として該無水ケイ酸を含有する水中油型乳化組成物。【選択図】なし
