| 摘要 |
<p>PURPOSE:To make a water repellent aggregate low in cost and high in durability and water repellency without using an expensive silicone resin or fluorinated resin by interlocking a water repellent silica powder on the surface of an inorganic or plastic fine particle. CONSTITUTION:This water repellent aggregate is produced by uniformly coating 100 pts.wt. inorganic aggregate such as gravel, sand or slag having 0.5-5mm particle diameter or a fine particle of plastics such as high density polyethylene and thermosetting resin having 0.1-5mm particle diameter, which has fastness not to be finely pulverized by operation such as stirring and is insoluble in a solvent and capable of controlling the penetration of water to a packed layer, with >=0.5 pts.wt. resin-based binder such as urethane resin having <=100cps viscosity as a solution, and sticking >=0.5 pts.wt. superfine powder silica obtained by treating a superfine powder inorganic silica having small bulk density and >=100m<2>/g specific surface area with a silylating agent such as methyl chlorosilane per 100 pts.wt. fine particle thereon, thereafter hardening the binder at room temp. to <=200 deg.C.</p> |
