| 摘要 |
<p>A concrete retarder comprises a polymer (A) having the concrete set retarding ability. The polymer (A) has, as a structural unit, a low glass transition temperature (Tg) component with a Tg of not higher than -5 DEG C, and a surface tension of 45 mN/m or lower. The proportion of the low Tg component having a glass transition temperature (Tg) of not higher than -5 DEG C is 10% by weight or more relative to the whole polymer (A). The polymer (A) has a functional group which can form a salt with a metal ion (particularly, a free acid group or a group capable of forming an acid group by hydrolysis). The polymer (A) is a vinyl-series polymer, a polyester (saturated or unsaturated polyester), or a crosslinked or graft polymerized unsaturated polyester. A sheet and a decorative pack may be formed with the concrete retarder. Removing smears on the tile preapplied concrete panel surface, wash of the concrete surface, and surface-finishing of the concrete can be made easier by the use of the retarder, sheet, or pack.</p> |
