To provide a damping water-borne coating composition which does not cause slippage, sagging, swelling, crack, foaming and pin holes even in a high film thickness.

This damping water-based coating composition comprises (A) a synthetic resin emulsion which is obtained from an α,β-unsaturated carboxylate-based monomer, one or more monomers selected from the group consisting of aromatic vinylic monomers and dienic monomers, and an α,β-unsaturated carboxylic acid as essential components, and has a glass transition temperature (Tg) of 0 to 60°C, the maximum tangent of loss angle (tan δ max) of ≥0.5, and an average particle diameter of 100 to 500 nm, such as a synthetic resin emulsion obtained from one or more monomers selected from the group consisting of an alkyl (meth)acrylate, styrene and butadiene, and (meth)acrylic acid as essential components, (B) a urea-based compound, (C) a filler, and (D) a foaming agent.

COPYRIGHT: (C)2005,JPO&NCIPI