| 摘要 |
PURPOSE:To obtain the waterproof material with reduced shrinkage when cured and having excellent waterproofness, softness, and adhesion to the backing by mixing cement, an aq. emulsion of a specified copolymer contg. PVA, and an aggregate. CONSTITUTION:The waterproof material consists essentially of cement, an aq. emulsion of an ethylene-acrylic ester-vinyl acetate copolymer having <=-30 deg.C glass transition temp.(Tg) and contg. PVA, and an aggregate. When the Tg is lower than -30 deg.C, sufficient softness (flexibility) as the waterproof material is not developed, the material is unable to follow up the impact in concrete placing and movement of the backing, and crazing and cracking are caused. The content of ethylene of the emulsion is preferably controlled to 10-30wt.%. When the ethylene content is lower than 10wt.%, the alkali resistance of the emulsion is insufficient. The emulsion is instabilized at >30wt.%, and the use is hindered. |
