Abstract: An object of the present invention is to provide an oil-in-water emulsion defoaming agent that is superior in defoaming properties (initial defoaming property and defoaming durability) and stability (emulsion stability). The present invention provides an oil-in-water emulsion defoaming agent including hydrophilic fumed silica (C), wherein an oil phase (A) is emulsified and dispersed in a water phase (B). Preferably, the content of the oil phase (A) is 10 to 50% by weight, the content of the hydrophilic fumed silica (C) is 0.1 to 6% by weight, and the content of the water phase (B) is 44 to 89.9% by weight based on the weight of the oil phase (A), the hydrophilic fumed silica (C), and the water phase (B). The weight ratio (A/C) of the oil phase (A) to the hydrophilic fumed silica (C) is preferably from 2 to 100.

Abstract: The present invention is a defoaming agent comprising a fatty acid amide (A), a base oil (B) that is liquid at 25° C., an oil thickening agent (C), and a surfactant (D), wherein the content of the fatty acid amide (A) is 1 to 10% by weight, the content of the base oil (B) that is liquid at 25° C. is 71 to 97.9% by weight, the content of the oil thickening agent (C) is 0.1 to 10% by weight, and the content of the surfactant (D) is 1 to 9% by weight based on the weight of the fatty acid amide (A), the base oil (B) that is liquid at 25° C., the oil thickening agent (C), and the surfactant (D), and the viscosity (25° C.) at a shear rate of 1000 s?1 is 0.1 to 1.0 Pa·s.

Abstract: An object of the present invention is to provide an oil-in-water emulsion defoaming agent that is superior in defoaming properties (initial defoaming property and defoaming durability) and stability (emulsion stability). The present invention provides an oil-in-water emulsion defoaming agent including hydrophilic fumed silica (C), wherein an oil phase (A) is emulsified and dispersed in a water phase (B). Preferably, the content of the oil phase (A) is 10 to 50% by weight, the content of the hydrophilic fumed silica (C) is 0.1 to 6% by weight, and the content of the water phase (B) is 44 to 89.9% by weight based on the weight of the oil phase (A), the hydrophilic fumed silica (C), and the water phase (B). The weight ratio (A/C) of the oil phase (A) to the hydrophilic fumed silica (C) is preferably from 2 to 100.

Abstract: The object of the present invention is to provide a defoaming agent that is superior in defoaming properties (foam-breaking, foam-inhibiting effect, defoaming durability). The present invention is a defoaming agent comprising a fatty acid amide (A), a base oil (B) that is liquid at 25° C., an oil thickening agent (C), and a surfactant (D), wherein the content of the fatty acid amide (A) is 1 to 10% by weight, the content of the base oil (B) that is liquid at 25° C. is 71 to 97.9% by weight, the content of the oil thickening agent (C) is 0.1 to 10% by weight, and the content of the surfactant (D) is 1 to 9% by weight based on the weight of the fatty acid amide (A), the base oil (B) that is liquid at 25° C., the oil thickening agent (C), and the surfactant (D), and the viscosity (25° C.) at a shear rate of 1000 s?1 is 0.1 to 1.0 Pa·s.