WATERPROOFING MATERIAL COMPOSITION

PROBLEM TO BE SOLVED: To provide a waterproofing material composition giving waterproof coating film slight in its surface tuck and high in extensibility, to provide such a waterproofing material coating film using the above composition, and to provide an application method for the waterproofing material coating film. SOLUTION: The waterproofing material composition comprises (A) a vinyl polymer comprising specific constituent monomer units and having a glass transition temperature of -20°C or lower, (B) a second vinyl polymer containing (meth)acrylic acid monomers as constituent units, 2,000-100,000 in weight-average molecular weight, 50-200 mgKOH/g in acid value and 0°C or higher in glass transition temperature, (C) an inorganic hydraulic material, and an aqueous medium. In this composition, the proportions of the vinyl polymer B and the inorganic hydraulic material C are 0.3-8 pts.mass and 10-200 pts.mass, based on 100 pts.mass of the vinyl polymer A, respectively. COPYRIGHT: (C)2009,JPO&INPIT