Antifoaming agent and water-based coating composition containing the same

摘要

PROBLEM TO BE SOLVED: To provide a defoaming agent exhibiting the high finishing property of a coating film and being excellent in the controllability (foam removal, foam-inhibiting property and the like) of bubbles at a low temperature.SOLUTION: A defoaming agent consisting of a glycidyl compound (GL) having general formula (1): {G(-OA)}-Q-{(AO-)H}(1) (wherein, G is glycidyl; Q is a reaction residue where a hydrogen atom is removed from the t pieces of the primary hydroxyl group of a non-reducing disaccharide or trisaccharide; OA and AO are 2-4C oxyalkylene groups; H is a hydrogen atom; n is an integer of 4-40; t is an integer of 2-4; p is an integer of 1-4 (tp); and the total number of oxyalkylene groups (OA and AO) in the glycidyl compound (GL) having the general formula (1) is an integer of 20-70) is used.